Description
MESSAGE EXCHANGE METHOD, WIRELESS COMMUNICATION SYSTEM,
WIRELESS TERMINAL, AND WIRELESS BASE STATION
Technical Field
The present invention relates to a message exchange
method, a wireless communication system, a wireless
terminal, and a wireless base station which are provided
for performing wireless communication. In particular, the
present invention relates to a message exchange method, a
wireless communication system, a wireless terminal, and a
wireless base station which perform processing for
allocating a bandwidth to the wireless terminal.
Background Art
The IEEE 802.16 Working Group (802.16 WG) specifies
a point-to-multipoint (P-MP) communication system which
enables connection of a plurality of terminals to a
wireless base station. The 802.16 WG provides two types of
standards 802.16d (IEEE 802.16-2004) and 802.16e (IEEE
802.16e-2005), where IEEE 802.16-2004 is provided mainly
for fixed communications, and IEEE 802.16e-2005 is
provided for mobile communications. The above standards
provide specifications for a plurality of physical layers,
and technologies such as OFDM (Orthogonal Frequency
Division Multiplex) or OFDMA (Orthogonal Frequency
Division Multiplex Access) are mainly used.
The standards 802.16d/e basically specify a point-
to-multipoint (P-MP) connection, in which a plurality of
wireless terminals (MSs) is connected to a wireless base
station (BS). MAC (Media Access Control) messages are
exchanged between the BS and each MS before communication
is started.
FIG. 24 is a sequence diagram indicating an outline
of a procedure for exchanging main MAC messages. In FIG.
24, only the main MAC messages are indicated. However, in
the practical use of the techniques in accordance with
IEEE 802.16d/e, the MS needs a wireless resource allocated
by the BS, when each MS transmits to the BS various
messages such as the MAC messages.
For example, although the CDMA Ranging Code can be
transmitted by use of a bandwidth which can be used by any
MS, the other messages following the CDMA Ranging Code
such as the "RNG-REQ" message are required to be
transmitted through a bandwidth allocated to each MS by
the BS. Therefore, in practice, signals or messages for
requesting a bandwidth or allocating a bandwidth are
exchanged between the BS and the MS before messages such
as the "RNG-REQ" message are transmitted from the MS to
the BS.
FIG. 25 is a sequence diagram indicating details of
a procedure for exchanging messages for bandwidth
allocation. In FIG. 25, details of messages preceding the
"SBC-REQ" message (which is indicated in the sequence
diagram of FIG. 24) are indicated, and the messages
necessary for allocation of a bandwidth are indicated by
dashed lines.
Here, a procedure for transmitting the "SBC-REQ"
message by the MS after the MS receives an "RNG-RSP"
message is briefly explained. First, the MS transmits a
"BW Request CDMA Code" message to the BS. The "BW Request
CDMA Code" message requests allocation of a bandwidth for
transmitting header information having a predetermined
length (6 bytes). When the BS receives the "BW Request
CDMA Code" message, the BS transmits to the MS a "UL-MAP"
message containing the information "CDMA Allocation IE"
for allocation, to the MS, of a bandwidth for an uplink
(from the MS to the BS) . The information "CDMA Allocation
IE" contains codes indicating a subchannel, a symbol, a
modulation technique, an encoding technique, and the like
for use by the MS. Thus, a bandwidth necessary for
transmission of the header information to the MS can be
allocated to the MS.
When the MS receives the above "UL-MAP" message, the
MS transmits to the BS a "Bandwidth Request Header"
message designating a bandwidth necessary for transmission
of the "SBC-REQ" message by using the allocated bandwidth.
The BS recognizes the bandwidth needed by the MS on the
basis of the "Bandwidth Request Header" message. Then, the
BS allocates the bandwidth to the MS, and transmits to the
MS a "UL-MAP" message indicating the allocated bandwidth.
When the MS receives the "UL-MAP" message, the MS
transmits the "SBC-REQ" message to the BS by use of the
allocated bandwidth.
The above communication procedure is indicated in
the IEEE 802.16d and IEEE 802.16e standards. (See the
nonpatent literatures 1 and 2.)
The nonpatent literature 1: "IEEE Standard for Local
and Metropolitan Area Networks Part 16: Air Interface for
Fixed Broadband Wireless Access System," IEEE Std 802.16-
2004, USA, IEEE, 1 October 2004
The nonpatent literature 2: "IEEE Standard for Local
and Metropolitan Area Networks Part 16: Air Interface for
Fixed and Mobile Broadband Wireless Access Systems,
Amendment for Physical and Medium Access Control Layers
for Combined Fixed and Mobile Operation in Licensed Bands"
IEEE Std 802.16e-2005 and IEEE Std 802.16-2004/Cor 1-2005,
USA, IEEE, 25 February 2006
Disclosure of Invention
Problems to be Solved by the Invention
In order to transmit a message uplink from the MS,
many preparatory messages are required to be exchanged for
requesting and allocating a bandwidth, and the exchange of
such messages increase delay and wastefully use bandwidths.
In the example of FIG. 25, the four messages are exchanged
for allocation of a bandwidth between the BS and the MS in
order to transmit an "SBC-REQ" message from the MS to the
BS.
In addition, when a message or the like on a
wireless link is discarded, it takes a long time before
the same message is resent.
The present invention is made in view of the above
problems, and the object of the present invention is to
provide a message exchange method, a wireless
communication system, a wireless terminal, and a wireless
base station which enable efficient message transmission
from the MS.
Means for Solving the Problems
In order to accomplish the above object, according
to the present invention, a message exchange method for
communication between a wireless terminal 1 and a wireless
base station 2 as illustrated in FIG. 1 is provided. The
wireless terminal 1 transmits a message parameter 3 to the
wireless base station 2. The message parameter 3 contains
identification information identifying a trigger message 4
and a message size indicating the data length of a message
6 to be transmitted, where the message 6 to be transmitted
is to be transmitted from the wireless terminal 1 to the
wireless base station 2, and the trigger message 4
triggers transmission of the message 6 to be transmitted.
Subsequently, the wireless base station 2 transmits the
trigger message 4 to the wireless terminal 1, and
thereafter allocates to the wireless terminal 1 a wireless
bandwidth corresponding to the message size of the message
6 to be transmitted. Further, the wireless base station 2
transmits to the wireless terminal 1 allocation
information 5 which indicates the allocated wireless
bandwidth. Then, the wireless terminal 1 transmits the
message 6 to be transmitted, to the wireless base station
2 by use of the wireless bandwidth indicated by the
allocation information 5.
In the above message exchange method, when the
wireless terminal 1 transmits the message parameter 3 to
the wireless base station 2, the wireless base station 2
transmits the trigger message 4 to the wireless terminal 1.
Thereafter, the wireless bandwidth corresponding to the
message size of the message 6 to be transmitted is
allocated to the wireless terminal 1. Further, the
wireless base station 2 transmits the allocation
information 5 to the wireless terminal 1. Then, the
wireless terminal 1 transmits the message 6 to be
transmitted, to the wireless base station 2.
Advantage of the Invention
According to the present invention, the wireless
base station is informed, in advance, of the
identification information identifying the trigger message
for the message to be transmitted and the message size of
the message to be transmitted. Therefore, the wireless
base station can allocate to the wireless terminal a
wireless bandwidth for transmission of the message to be
transmitted, without exchanging messages for bandwidth
allocation after transmission of the trigger message. As a
result, the communication efficiency in message exchange
between the wireless terminal and the wireless base
station is improved.
The above and other objects, features and advantages
of the present invention will become apparent from the
following description when taken in conjunction with the
accompanying drawings which illustrate preferred
embodiment of the present invention by way of example.
Brief Description of Drawings
FIG. 1 is a diagram illustrating an outline of the
present invention.
FIG. 2 is a diagram illustrating an example of a
system configuration according to embodiments.
FIG. 3 is a block diagram illustrating the functions
of a wireless base station (BS).
FIG. 4 is a block diagram illustrating the functions
of a wireless terminal (MS).
FIG. 5 is a diagram illustrating data tables stored
in a storage in the BS.
FIG. 6 is a diagram illustrating data tables stored
in a storage in the MS.
FIG. 7 is a diagram indicating a sequence of
messages exchanged when the MS starts an operation for
connection to the BS in the first embodiment.
FIG. 8 is a diagram indicating a sequence of
messages in the case where a plurality of error processing
operations are combined.
FIG. 9 is a first flow diagram indicating operations
performed by a controller in the BS.
FIG. 10 is a second flow diagram indicating
operations performed by the controller in the BS.
FIG. 11 is a third flow diagram indicating
operations performed by the controller in the BS.
FIG. 12 is a first flow diagram indicating
operations performed by a controller in the MS.
FIG. 13 is a second flow diagram indicating
operations performed by the controller in the MS.
FIG. 14 is a diagram illustrating the contents of
the storage in the BS in the second embodiment.
FIG. 15 is a diagram illustrating the contents of
the storage in the MS in the second embodiment.
FIG. 16 is a diagram indicating a sequence of
messages exchanged when the MS starts an operation for
connection to the BS in the second embodiment.
FIG. 17 is a state transition diagram of the BS.
FIG. 18 is a flow diagram indicating operations
performed by the controller in the BS in the second
embodiment.
FIG. 19 is a flow diagram indicating operations
performed by the controller in the MS in the second
embodiment.
FIG. 20 is a diagram illustrating the contents of
the storage in the BS in the third embodiment.
FIG. 21 is a diagram indicating a sequence of
messages exchanged when the MS starts an operation for
connection to the BS in the third embodiment.
FIG. 22 is a flow diagram indicating operations
performed by the MS when the MS receives a "UCD" message.
FIG. 23 is a flow diagram indicating operations
performed by the MS after the MS transmits a CDMA Ranging
Code until the MS transmits an "SBC-REQ" message.
FIG. 24 is a sequence diagram indicating an outline
of a procedure for exchanging main MAC messages.
FIG. 25 is a sequence diagram indicating details of
a procedure for exchanging messages for bandwidth
allocation.
Best Mode for Carrying Out the Invention
Hereinbelow, the embodiments of the present
invention are explained with reference to drawings.
FIG. 1 is a diagram illustrating an outline of the
present invention. As illustrated in FIG. 1, in the
wireless communication system according to the present
invention, messages are wirelessly exchanged between the
wireless terminal 1 and the wireless base station 2.
The wireless terminal 1 comprises a message-
parameter transmission means la and a message transmission
means lb. The message-parameter transmission means la
transmits a message parameter 3 to the wireless base
station 2. The message parameter 3 contains identification
information identifying a trigger message 4, the message
size indicating the data length of a message 6 to be
transmitted, and a time of delay occurring after the
wireless terminal 1 receives the trigger message 4 until
preparations for transmission of the message 6 to be
transmitted are completed, where the message 6 to be
transmitted is to be transmitted from the wireless
terminal 1 to the wireless base station 2, and the trigger
message 4 triggers transmission of the message 6 to be
transmitted. In the example of FIG. 1, the identification
information identifying the trigger message 4 is "Msg#1,"
and the message size is 30 bytes, and the time of delay is
10 ms.
When the message transmission means lb receives the
trigger message 4 from the wireless base station 2, the
message transmission means lb starts preparation for
transmission of the message 6 to be transmitted. In
addition, when the message transmission means lb receives
allocation information 5 which indicates a wireless
bandwidth allocated by the wireless base station 2, the
message transmission means lb transmits the message 6 to
be transmitted, to the wireless base station 2 by use of
the wireless bandwidth indicated by the allocation
information 5. The wireless base station 2 comprises a
trigger-message transmission means 2a, a bandwidth
allocation means 2b, and an allocation-information
transmission means 2c.
The trigger-message transmission means 2a transmits
the trigger message 4 to the wireless terminal 1 in
accordance with a predetermined message exchange sequence.
When the bandwidth allocation means 2b receives the
message parameter 3 from the wireless terminal 1, and the
time of delay elapses since the transmission of the
trigger message 4 by the trigger-message transmission
means 2a, the bandwidth allocation means 2b allocates to
the wireless terminal 1 the wireless bandwidth in
correspondence with the message size of the message 6 to
be transmitted. The allocation-information transmission
means 2c transmits to the wireless terminal 1 the
allocation information 5 indicating the wireless bandwidth
allocated by the bandwidth allocation means 2b.
In the above wireless communication system, when the
wireless terminal 1 transmits the message parameter 3 to
the wireless base station 2, the wireless base station 2
transmits the trigger message 4 to the wireless terminal 1
in accordance with the message exchange sequence. When the
time of delay elapses since the transmission of the
trigger message 4, the wireless bandwidth corresponding to
the message size of the message 6 to be transmitted is
allocated to the wireless terminal 1. In addition, the
wireless base station 2 transmits the allocation
information 5 to the wireless terminal 1. Then, the
wireless terminal 1 transmits the message 6 to be
transmitted, to the wireless base station 2.
Thus, the wireless base station 2 can allocate to
the wireless terminal 1 the wireless bandwidth for
transmission of the message 6 to be transmitted, without
exchanging messages for bandwidth allocation after
transmission of the trigger message 4. As a result, the
communication efficiency in message exchange between the
wireless terminal 1 and the wireless base station 2 is
improved.
Further, since the wireless base station 2 receives
as the time of delay the time necessary for preparation
for the transmission of the message 6 to be transmitted,
the wireless base station 2 allocates the bandwidth after
the time of delay elapses since the transmission of the
trigger message 4. Therefore, the wireless terminal 1 can
transmit the message 6 to be transmitted immediately after
the wireless base station 2 allocates the bandwidth. As a
result, it is possible to facilitate efficient use of the
wireless bandwidth.
In the case where the above processing for the
bandwidth allocation is performed when various messages to
be transmitted are transmitted by the wireless terminal 1,
it is possible to greatly reduce the time needed for
requesting and allocating bandwidths used for the messages
to be transmitted.
In the example of FIG. 1, the wireless base station
2 is informed of the timing of the start of the operation
for bandwidth allocation by insertion of the time of delay
in the message parameter 3. This is effective in the case
where the time necessary for preparation for transmission
of the message 6 to be transmitted by the wireless
terminal 1 is fixed. In the case where the time necessary
for preparation for transmission and reception of the
message 6 to be transmitted is not fixed, the wireless
terminal 1 may request bandwidth allocation by
transmitting identification information which is unique to
the wireless terminal 1 to the wireless base station. At
this time, the amount of the wireless resource (bandwidth)
to be allocated is determined according to the message
size, of which the wireless base station 2 is informed by
the wireless terminal 1 in advance.
Hereinbelow, details of the embodiments are
explained for exemplary cases where the present invention
is applied to wireless communications in accordance with
the IEEE 802.16d/e standards.

FIG. 2 is a diagram illustrating an example of a
system configuration according to the first embodiment.
The wireless communications according to the first
embodiment are performed between the wireless base station
(BS) 100 and a plurality of wireless terminals (MSs) 200,
200a, and 200b. The MSs 200, 200a, and 200b are located
within the area covered by the BS 100. The BS 100 is
connected to a router 300. The router 300 is further
connected to the wireless base stations (BSs) 100, 100a,
and 100b, and controls routing of data such as packet data
which are received through the BSs 100, 100a, and 100b.
The communication method according to the first
embodiment is explained below by taking as an example the
communication between the BS 100 and the MS 200.
FIG. 3 is a block diagram illustrating the functions
of the wireless base station (BS) . The BS 100 has an
antenna 111 and a duplexer 112. The antenna 111 is
provided for transmitting and receiving wireless signals
to and from wireless terminals, and the duplexer 112 is
provided for commonly using the antenna 111 for
transmission and reception.
A part of the BS 100 arranged for reception from the
MS 200 comprises a receiver 121, a demodulator 122, a
decoder 123, a control-message extractor 124, and a packet
re-assembler 125.
The receiver 121 receives through the duplexer 112
signals inputted into the antenna 111, and passes the
received signals to the demodulator 122. The demodulator
122 demodulates the received signals, and passes the
demodulated signals to the decoder 123. The decoder 123
decodes the demodulated signals into decoded data, and
passes the decoded data to the control-message extractor
124.
The control-message extractor 124 extracts control
data from the decoded data, and passes the control data to
a controller 150. In addition, the control-message
extractor 124 transfers to the packet re-assembler 125
data (such as user data) other than the control data. The
packet re-assembler 125 packetizes the data transferred
from the control-message extractor 124, and passes the
packetized data to an NW (network) interface 130.
The NW interface 130 is an interface provided for
communication with the router 300. The NW interface 130
transmits a packet passed to the NW interface 130 by the
packet re-assembler 125, to the router 300 through a
network. When the NW interface 130 receives a packet from
the router 300, the NW interface 130 passes the packet to
a packet classifier 141.
A part of the BS 100 arranged for transmission to
the MS comprises the packet classifier 141, a packet
buffer 142, a PDU (Protocol Data Unit) generator 143, an
encoder 144, a modulator 145, and a transmitter 146. The
packet classifier 141 recognizes the IP (Internet
Protocol) address of the destination contained in the
packet received from the NW interface 130, and identifies
the MS as the destination on the basis of the IP address.
For example, the packet classifier 141 stores in advance
in a memory a table (address table) in which the
correspondences between the IP addresses and the IDs of
the MSs are recorded. When the packet classifier 141
receives a packet, the packet classifier 141 refers to the
address table, and acquires the ID of the destination MS
(i.e., the MS corresponding to the destination IP address
in the packet).
In addition, the packet classifier 141 acquires a
QoS (Quality of Service) information corresponding to the
ID of the destination MS when the packet classifier 141
receives the packet. For example, the packet classifier
141 stores in advance in the memory a table (QoS table) in
which the correspondences between the QoS information
items and the IDs of the MSs are recorded. When the packet
classifier 141 receives a packet, the packet classifier
141 refers to the QoS table, and acquires the QoS
information corresponding to the ID of the destination MS.
When the packet classifier 141 acquires the ID and
the QoS information for the destination MS, the packet
classifier 141 supplies to the controller 150 the ID and
the QoS information for the destination MS and the data
size, and sends out a request for bandwidth allocation.
Then, the packet classifier 141 stores in the packet
buffer 142 a packet passed to the packet classifier 141 by
the NW interface 130. The packet buffer 142 temporarily
holds the packet which is to be transmitted to the MS.
The PDU generator 143 acquires user data from the
packet stored in the packet buffer 142 and control data
from the controller 150 in accordance with an instruction
from the controller 150 to transmit data. In addition, the
PDU generator 143 generates a PDU by inserting data which
is to be transmitted and is constituted by the user data
and the control data, into a wireless frame, which is
formed with a synchronization signal (preamble) as a
reference. Then, the PDU generator 143 transmits the
generated PDU to the encoder 144.
The encoder 144 performs processing for encoding
(such as error-correcting coding) of the PDU received from
the PDU generator 143. Then, the encoder 144 passes the
encoded PDU data to the modulator 145. The modulator 145
modulates the PDU data received from the encoder 144, and
passes the modulated PDU data to the transmitter 146. The
transmitter 146 wirelessly transmits through the antenna
111 the modulated PDU data in the form of a wireless
signal.
When the controller 150 receives from the packet
classifier 141 a request for bandwidth allocation for the
downlink traffic (in the direction from the BS to the MS),
the controller 150 selects an MS for which a bandwidth is
requested to be allocated, according to the QoS
information. Then, the controller 150 instructs the packet
buffer 142 and the PDU generator 143 to perform scheduling
of transmission of the user data. In addition, the
controller 150 also produces the control data, and passes
the produced control data to the PDU generator 143.
In addition, the controller 150 allocates to the MS
200 an uplink bandwidth for the uplink traffic (in the
direction from the MS to the BS) in response to a request
for a bandwidth, which is received from the MS 200.
Further, when the controller 150 transmits a message for
triggering transmission of predetermined control data from
the MS 200, and a predetermined time of delay is measured
by a timer, the controller 150 automatically allocates an
uplink bandwidth to the MS 200. Furthermore, when the
controller 150 transmits the message for triggering the
transmission, the controller 150 generates allocation
information on the bandwidth allocation, and instructs the
PDU generator 143 to transmit to the MS 200 control data
containing the generated allocation information.
Moreover, the controller 150 performs processing of
the received control data. For example, the controller 150
performs processing for registration, authentication,
generation and exchange of a key, state management of
wireless channels, and the like for the functions
supported by the MS 200. A storage 160 is connected to the
controller 150, and the controller 150 stores data
necessary for various processing in the storage 160, and
reads out the data from the storage 160.
The storage 160 stores various data which the BS 100
should store. For example, the storage 160 stores
information on the functions of the MS 200, information on
authentication, information on the key, information on the
wireless channels, and the like, which are contained in
the control data received from the MS 200, as well as
management information on the status of use of the
resources in the MS 200.
In addition, a TLV definition table and a
transmission-trigger table are stored in advance in the
storage 160. The TLV table stores definitions of TLV
parameters, and the transmission-trigger table stores
definitions of transmission triggers which trigger the
bandwidth allocation. Further, when the MS 200 is
connected, a bandwidth-allocation management table is
stored in the storage 160 in association with the MS 200.
In the bandwidth-allocation management table, the message
size and the time of delay related to bandwidth allocation
are defined. Details of the above tables stored in the
storage 160 are explained later.
FIG. 4 is a block diagram illustrating the functions
of a wireless terminal (MS). The MS 200 comprises an
antenna 211 and a duplexer 212. The antenna 211 is
provided for transmitting and receiving wireless signals
to and from the BS 100, and the duplexer 212 is provided
for commonly using the antenna 211 for transmission and
reception.
The MS 200 comprises a reception processor 220,
which includes a receiver 221, a demodulator 222, a
decoder 223, and a control-message extractor 224.
The receiver 221 receives through the duplexer 212
signals inputted into the antenna 211, and passes the
received signals to the demodulator 222. The demodulator
222 demodulates the received signals, and passes the
demodulated signals to the decoder 223. The decoder 223
decodes the demodulated signals into decoded data, and
passes the decoded data to the control-message extractor
224. The control-message extractor 224 extracts control
data from the decoded data, and passes the control data to
a controller 250. In addition, the control-message
extractor 224 transfers to a data processor 230 data (such
as user data) other than the control data.
The data processor 230 performs processing for
displaying various data included in the received data,
processing for outputting sound, and the like. In addition,
the data processor 230 sends to a PDU buffer 241 user data
which is desired to be transmitted to a destination device.
The transmission processor 240 comprises the PDU
buffer 241, an encoder 242, a modulator 243, and a
transmitter 244. The PDU buffer 241 holds data which is to
be transmitted and is received from the data processor 230,
and the PDU buffer 241 outputs the held data to the
encoder 242 in accordance with an instruction from the
controller 250.
The encoder 242 encodes the data which is to be
transmitted and is received from the PDU buffer 241, under
control of the controller 250, and the encoder 242 passes
the data which is to be transmitted and is encoded, to the
modulator 243. The modulator 243 performs processing for
modulation of the data which is to be transmitted and is
encoded, and passes the data which is to be transmitted
and is modulated, to the transmitter 244. The transmitter
244 wirelessly transmits the data which is to be
transmitted and is modulated, in the form of a wireless
signal through the antenna 211.
The controller 250 performs processing of control
data which are transmitted to or received from the BS 100.
For example, the controller 250 performs processing for
registration, authentication, generation and exchange of a
key, state management of wireless channels, and the like
for the functions supported by the MS 200. In addition,
the controller 250 transmits user data or control data to
the BS 100 by controlling the transmission processor 240
on the basis of the allocation information for an uplink
bandwidth, which is transmitted from the BS 100. When
bandwidth allocation is necessary, the controller 250
instructs the transmission processor 240 to transmit to
the BS 100 a signal or a message for requesting the
bandwidth allocation.
A storage 260 is connected to the controller 250.
The controller 250 stores in the storage 260 data
necessary for data processing, bandwidth allocation
information transmitted from the BS 100, and the like.
The storage 260 stores data necessary for processing
performed by the controller 250. In addition, the storage
260 stores a message-information management table, in
which the message sizes and the times of delay are
recorded for messages transmitted uplink from the MS 200
to the BS 100.
Next, the contents of the data tables stored in the
storage 160 in the BS 100 and the storage 260 in the MS
200 are explained below.
FIG. 5 is a diagram illustrating the data tables
stored in the storage in the BS. The TLV definition table
161 and the transmission-trigger table 162 are stored in
advance in the storage 160. In addition, when the MS 200
is connected, the controller 150 produces a parameter
table 163, and stores the parameter table 163 in the
storage 160. In FIG. 5, only the data tables which are
necessary for bandwidth allocation are indicated among the
information stored in the storage 160. That is, in
practice, the storage 160 further stores various data
which are not indicated in FIG. 5.
The TLV definition table 161 has the columns of
"Type," "Length," and "Value." The information items
arranged along each row are related to each other, and
constitute a data structure of a TLV parameter of a type.
For example, one type of TLV parameter defined in the TLV
definition table 161 is a TLV parameter for transmission
of bandwidth allocation information.
The data type of the information indicated in the
column "Value" is indicated in the column "Type." The data
length of the information indicated in the column "Value"
is indicated in the column "Length." The data length of
the information indicated in the column "Value" of the TLV
parameter for transmission of bandwidth allocation
information is three bytes. The information which is
actually transmitted as the value of the TLV parameter is
indicated in the column "Value." In the value of the TLV
parameter for transmission of bandwidth allocation
information, the size of the message to be transmitted is
indicated (in bytes) in the leading ten bits, the time of
delay is indicated (in frames) in the subsequent six bits,
and the transmission trigger ID is indicated in the
remaining eight bits. The transmission trigger ID is
identification information for identifying a trigger
(transmission trigger) which indicates the timing of
transmission of predetermined control data by the MS 200.
The transmission-trigger table 162 has the columns
of "Transmission Trigger ID," "Transmission Trigger," and
"Transmitted Message."
The identification information (transmission trigger
ID) assigned to each transmission trigger is set in the
column "Transmission Trigger ID." The event which triggers
transmission of control data by the MS 200 is set in the
column "Transmission Trigger." The type of the message to
be transmitted from the MS 200 in response to each
transmission trigger is set in the column "Transmitted
Message."
In the example of FIG. 5, the reception of the "RNG-
RSP" message is set as the transmission trigger in
correspondence with the transmission trigger ID "1." When
the MS 200 receives the "RNG-RSP" message, the MS 200
transmits an "SBC-REQ" message to the BS 100. In addition,
the reception of the "PKMv2-RSP (Key-Reply)" message is
set as the transmission trigger in correspondence with the
transmission trigger ID "2." When the MS 200 receives the
"PKMv2-RSP (Key-Reply)" message, the MS 200 transmits a
"REG-REQ" message to the BS 100.
The parameter table 163 has the columns of
"Transmission Trigger ID," "Delay Time," and "Message
Size." The trigger ID indicating an event (message
reception) which triggers transmission of a message by the
MS 200 is set in the column "Transmission Trigger ID." The
minimum value of the time of delay occurring until
preparations for transmission of the message to be
transmitted by the MS 200 in response to the transmission
trigger indicated by the transmission trigger ID are
completed is set in the column "Delay Time." The amount of
the data of the message which is to be transmitted by the
MS 200 in response to the transmission trigger indicated
by the transmission trigger ID is set in the column
"Message Size."
FIG. 6 is a diagram illustrating a data table stored
in the storage in the MS. The storage 260 in the MS 200
stores a TLV definition table 261, a transmission-trigger
table 262, and the message-information management table
263.
The data structure of the TLV definition table 261
and the data recorded in the TLV definition table 261 are
identical to the TLV definition table 161 stored in the
storage 160 in the BS 100. In addition, the data structure
of the transmission-trigger table 262 and the data
recorded in the transmission-trigger table 262 are
identical to the transmission-trigger table 162 stored in
the storage 160 in the BS 100.
The message-information management table 263 has the
columns of "Transmitted Message," "Message Size," and
"Delay Time." When an "RNG-REQ" message is transmitted
from the MS 200, predetermined data contained in the "RNG-
REQ" message are recorded in the message-information
management table 263.
The type of the message transmitted by the MS 200 in
response to each transmission trigger is set in the column
"Transmitted Message." The size of each message
transmitted from the MS 200 is set (in bytes) in the
column "Message Size." The time of delay of each message
transmitted from the MS 200 is set in the column "Delay
Time." The time of delay of each message is the minimum
value of the time necessary after the MS 200 receives a
transmission trigger until the MS 200 transmits the
corresponding message. This means that the MS 200 does not
transmit a predetermined message until the time of delay
elapses after the BS 100 transmits a message as a
transmission trigger. Therefore, it is sufficient for the
BS 100 to allocate a bandwidth to the MS 200 when the time
of delay elapses since the transmission of a message as a
transmission trigger.
Since the BS 100 and the MS 200 are configured as
above, it is possible to efficiently uplink control data
from the MS 200 to the BS 100.
FIG. 7 is a diagram indicating a sequence of
messages exchanged when the MS starts an operation for
connection to the BS in the first embodiment. In FIG. 7,
the exchanged messages are indicated by arrow lines, the
types of the messages are indicated above the arrow lines,
and the data contained in the messages are indicated in
parentheses following the types of the messages. In
addition, the signals and messages for requesting and
allocating a bandwidth are indicated by dashed lines, and
the main messages for exchanging information on
authentication and the like between the MS 200 and the BS
100 are indicated by solid lines.
Further, the curved dashed lines shown on the BS 100
side with arrows each indicate processing for allocation
of a bandwidth, and extend from a message causing the
processing for bandwidth allocation to a message informing
the MS 200 of details of the bandwidth allocation. As
indicated in FIG. 7, a plurality of messages are exchanged
when the MS 200 starts the operation for connection of the
MS 200 to the BS 100 (i.e., the operation for network
entry). At this time, the order of exchange of the
messages (i.e., the message exchange sequence) is
predetermined.
First, the main messages exchanged when the MS 200
starts the operation for connection of the MS 200 to the
BS 100 are explained below with reference to FIG. 7. When
a request for connection to the BS 100 is inputted into
the MS 200 by a user's manual operation, the MS 200
transmits the CDMA Ranging Code to the BS 100. Then, the
BS 100 transmits an "RNG-RSP (Success Status)" message to
the MS 200.
Subsequently, the MS 200 transmits an "RNG-REQ (MAC
Address, etc)" message to the BS 100. In response to the
"RNG-REQ (MAC Address, etc)" message, the BS 100 registers
the MAC address of the MS 200. Then, the BS 100 allocates
a Basic CID and a Primary CID and transmits an "RNG-RSP
(Basic/Primary CID, etc)" message to the MS 200.
After that, the MS 200 transmits an "SBC-REQ"
message to the BS 100. In response to the "SBC-REQ"
message, the BS 100 transmits an "SBC-RSP" message to the
MS 200. Thus, negotiations for the authentication
technique and the functions in the physical layer which
are used in the communication are performed, where the
functions in the physical layer include the modulation
technique, the error-correcting coding technique, the H-
ARQ technique, and the like which are supported.
Thereafter, the BS 100 performs authentication, and
determines whether or not to permit the connection by
exchanging the PKM-REQ message and the PKM-RSP message
multiple times. When the authentication of the MS 200
succeeds and the connection is possible, the MS 200
transmits an "REG-REQ" message to the BS 100. In response
to the "REG-REQ" message, the BS 100 transmits an "REG-
RSP" message to the MS 200. Thus, negotiations for
functional parameters and the like for setting up a
connection for data transfer are performed as above.
In principle, bandwidth allocation by the BS 100 is
necessary every time an uplink message is transmitted from
the MS 200 to the BS 100 during the exchange of the main
messages, although the CDMA Ranging Code can be
transmitted by use of a bandwidth which can be used by all
the MSs since the MS 200 receives the "UL-MAP (DDMA
Ranging Opportunity)" message from the BS 100 in advance.
Each message transmitted from the MS 200 other than
the CDMA Ranging Code is transmitted by using a bandwidth
uniquely allocated to the MS 200 by the BS 100. In order
to allocate the bandwidth to the MS 200, the BS 100 is
required to recognize the size and the time of delay of
the message to be transmitted from the MS 200.
That is, in order to realize efficient use of the
communication bandwidth, it is necessary to allocate to
each MS the minimum bandwidth necessary for message
transmission, for the shortest possible time. Therefore,
in the case where a certain time is necessary for
preparation for transmission of a message by the MS 200,
the BS 100 allocates a bandwidth to the MS 200 after the
time necessary for the preparation for transmission
elapses. Thus, it is possible to minimize the time since
allocation of a bandwidth until transmission of a message
by use of the bandwidth. In addition, allocation of the
minimum necessary bandwidth to the MS 200 can be realized
by allocating a bandwidth according to the size of the
message to be transmitted by the MS 200.
When the MS 200 receives a "RNG-RSP (Success
Status)" message, the MS 200 transmits a "RNG-REQ (MAC
Address, etc)" message. It is known that preparations for
the transmission of the "RNG-REQ (MAC Address, etc)"
message can be completed in the minimum time of delay. In
addition, the message size of the "RNG-REQ (MAC Address,
etc)" message is also known from the standard. That is,
the BS 100 knows in advance the message size of the "RNG-
REQ (MAC Address, etc)" message and the time of delay for
the preparation for the transmission of the "RNG-REQ (MAC
Address, etc)" message. Therefore, the BS 100 can allocate
a bandwidth to the MS 200, and transmit a "UL-MAP (CDMA
Allocation IE)" message to the MS 200 immediately after
the transmission of the "RNG-RSP (Success Status)" message
from the BS 100. However, the message sizes and the times
of delay of the other main messages transmitted from the
MS 200 to the BS 100 are different for each MS. Therefore,
conventionally, more than one message is required to be
exchanged for bandwidth allocation as indicated in FIG. 24.
Consider the contents of the main messages
transmitted from the MS 200 to the BS 100. For some of the
main messages transmitted from the MS 200 to the BS 100,
the message size and the time of delay can be defined as
fixed values in advance in the MS 200. Specifically, the
"SBC-REQ" message (which is transmitted by the MS 200
after the MS 200 receives an "RNG-RSP" message containing
the "Basic/Primary CID" and the like) and the "REG-REQ"
message (which is transmitted by the MS 200 after
authentication succeeds and the MS 200 receives a "PKM-
RSP" message representing a key exchange) are messages
containing information unique to the MS 200 and having a
predetermined message size. In addition, the "SBC-REQ"
message or the "REG-REQ" message can be transmitted
without necessity of complicated processing after the
reception of the "RNG-RSP" or "PKM-RSP" message. Therefore,
the preparations for transmission of the "SBC-REQ" message
or the "REG-REQ" message can be completed with minimum
delay.
In consideration of the above situation, according
to the present embodiment, the MS 200 inserts information
recorded in the message-information management table 263
into a message which is transmitted to the BS 100 before
the MS 200 receives the first message which becomes a
transmission trigger (i.e., the "RNG-RSP (Basic/Primary
CID, etc)" message). That is, the MS 200 transmits to the
BS 100 an "RNG-REQ" message containing a message parameter
20, which includes the message sizes of the "SBC-REQ"
message and the "REG-REQ" message, the time of delay-
occurring after the MS 200 receives the "RNG-RSP
(Basic/Primary CID, etc)" message until the MS 200 becomes
ready to transmit the "SBC-REQ" message, and the time of
delay occurring after the MS 200 receives the "PKMv2-RSP
(Key-Reply)" message until the MS 200 becomes ready to
transmit the "REG-REQ" message. Then, the BS 100 produces
the parameter table 163 on the basis of the message
parameter, and stores the parameter table 163 in the
storage 160.
The BS 100 allocates to the MS 200 a bandwidth for
transmission of each of the "SBC-REQ" message and the
"REG-REQ" message at an appropriate time on the basis of
the parameter table 163. Specifically, the BS 100 waits
the time of delay for the "SBC-REQ" message after the BS
100 transmits the "RNG-RSP (Basic/Primary CID, etc)"
message, allocates a bandwidth corresponding to the
message size of the "SBC-REQ" message, and transmits an
"UL-MAP (Burst Allocation)" message to the MS 200. Further,
the BS 100 waits the time of delay for the "REG-REQ"
message after the BS 100 transmits the "PKMv2-RSP (Key-
Reply) " message, allocates a bandwidth corresponding to
the message size of the "REG-REQ" message, and transmits
an "UL-MAP (Burst Allocation)" message to the MS 200.
As explained above, the number of messages exchanged
for bandwidth allocation can be reduced, so that the
communication efficiency in the operation for connection
of the MS 200 to the BS 100 can be increased.
In the example of FIG. 7, it is assumed that all the
messages normally reach the destination. However, in some
environments of the MS 200 during the wireless
communication, the possibility that some messages cannot
be normally received is not ignorable.
According to the present embodiment, the messages
are transmitted and received at predetermined timings.
Therefore, in the case where a message is not received at
a predetermined timing, it is possible to immediately
detect that the message does not normally reach the
destination. Thus, a measure such as retransmission can be
quickly taken.
Specifically, in the case where the BS 100 cannot
receive the "SBC-REQ" message at the timing at which the
"SBC-REQ" message is to be received, the BS 100 performs
one of the following error processing operations.
(a) Retransmission of a main message which is
precedingly transmitted toward the MS 200
(b) Reallocation of a bandwidth
(c) Ranging processing (adjustment of transmission
parameters of the MS 200)
According to the present embodiment, the error
processing to be performed is determined according to the
error.
FIG. 8 is a diagram indicating a sequence of
messages in the case where a plurality of error processing
operations is combined. When the BS 100 receives the "RNG-
REQ" message from the MS 200, the BS 100 transmits an
"RNG-RSP" message to the MS 200. When a predetermined time
elapses since the transmission of the "RNG-RSP" message,
the BS 100 transmits to the MS 20.0 a "UL-MAP" message
containing information for allocating a wireless resource
for transmitting the "SBC-REQ" message. In the example of
FIG. 8, it is assumed that the "RNG-RSP" message and the
"UL-MAP" message cannot be normally received by the MS 200.
In the above case, since the MS 200 cannot normally
receive the responses (the "RNG-RSP" message and the "UL-
MAP" message) from the BS 100, the MS 200 cannot recognize
that the BS 100 allocates a wireless resource to the MS
200, so that the wireless resource allocated to the MS 200
by the BS 100 is not used.
The BS 100 detects that no signal is transmitted to
the wireless resource allocated to the MS 200 (i.e., the
BS 100 detects the "No Signal" state). Specifically, the
BS 100 detects the "No Signal" state when the BS 100 does
not receive a signal from the MS 200 even after a preset
time elapses since the allocation of a bandwidth to the MS
200. When the BS 100 detects the "No Signal" state, the BS
100 cannot determine whether or not the message which is
precedingly transmitted reaches the MS 200.
Therefore, the BS 100 performs the aforementioned
error processing operation (a). That is, the BS 100
performs retransmission of the "RNG-RSP" message,
reallocation of a bandwidth to the MS 200, and
transmission of a "UL-MAP" message. At this time, the BS
100 increments a retransmission number counter by one.
When the MS 200 receives the retransmitted "RNG-RSP"
message and the transmitted "UL-MAP" message indicating
details of the reallocation of the bandwidth, the MS 200
transmits the "SBC-REQ" message to the BS 100 by use of
the allocated wireless resource. However, in this example,
it is assumed that the BS 100 detects a CRC (Cyclic
Redundancy Check) error in the "SBC-REQ" message at this
time. When the BS 100 detects a CRC error, the BS 100 can
recognize that the MS 200 transmits some message by use of
the bandwidth reallocated to the MS 200, and determine
that the preceding "RNG-RSP" message and "UL-MAP" message
normally reach the MS 200.
In the above situation, the BS 100 performs the
aforementioned error processing operation (b) . That is,
when the BS 100 detects that the BS 100 cannot normally
receive the "SBC-REQ" message because of the CRC error,
the BS 100 reallocates a bandwidth to the MS 200, and
retransmits a "UL-MAP" message to the MS 200. At this time,
the BS 100 increments the retransmission number counter by
one.
When the MS 200 does not receive the "SBC-RSP"
message and receives the bandwidth allocation, the MS 200
determines that the BS 100 cannot normally receive the
"SBC-REQ" message. Therefore, the MS 200 retransmits the
"SBC-REQ" message. If the retransmitted "SBC-REQ" message
cannot be normally received, and a CRC error occurs, the
BS 100 performs the aforementioned error processing
operation (b) again. That is, a bandwidth is reallocated
to the MS 200, a "UL-MAP" message is retransmitted to the
MS 200, and the retransmission number counter is
incremented by one.
The maximum retransmission number is stored in
advance in the storage 160 in the BS 100. Every time the
BS 100 detects an error, the controller 150 compares the
value of the retransmission number counter with the
maximum retransmission number. When the value of the
retransmission number counter is equal to or greater than
the maximum retransmission number, the BS 100 performs the
aforementioned error processing operation (c) . That is,
the BS 100 transmits to the MS 200 an "RNG-RSP" message
containing the Continue Status, and prompts the MS 200 to
transmit the CDMA Ranging Code for adjustment of the
transmission parameters (of the transmission power,
frequency, and timing).
When the MS 200 receives the RNG-RSP" message
containing the Continue Status, the MS 200 transmits the
CDMA Ranging Code to the BS 100. When the BS 100 receives
the CDMA Ranging Code, the BS 100 determines whether or
not the reception power, frequency, and timing in the CDMA
Ranging Code are within specified ranges. In the case
where one or more of the reception power, frequency, and
timing in the CDMA Ranging Code are outside one or more of
the specified ranges, the BS 100 transmits to the MS 200
an "RNG-RSP" message containing one or more adjustment
values for the one or more of the transmission parameters,
and prompts the MS 200 to transmit the CDMA Ranging Code
again.
When the MS 200 receives the "RNG-RSP" message
containing the one or more adjustment values for the one
or more of the transmission parameters, the MS 200
performs the instructed adjustment, and thereafter
transmits the CDMA Ranging Code to the BS 100. When the BS
100 receives the CDMA Ranging Code, the BS 100 determines
whether or not the reception power, frequency, and timing
in the CDMA Ranging Code are within specified ranges. In
the case where the reception power, frequency, and timing
in the CDMA Ranging Code are within the specified ranges,
the BS 100 transmits to the MS 200 an "RNG-RSP" message
containing the Success Status. Then, the BS 100 allocates
a bandwidth to the MS 200 for transmission of an "SBC-REQ"
message, and transmits an "UL-MAP (Burst Allocation)"
message to the MS 200.
As explained above, a highly reliable message
exchange can be realized by combining the plurality of
error processing operations.
Next, sequences of operations performed by the
controller 150 in the BS 100 and the controller 250 in the
MS 200 for realizing the processing indicated in FIGS. 7
and 8 are explained in detail. First, the operations
performed by the controller 150 from the acquisition of
the CDMA Ranging Code to the transmission of the "SBC-RSP"
message are explained below with reference to FIGS. 9 to
11.
FIG. 9 is a first flow diagram indicating operations
performed by the controller in the BS. The operations of
FIG. 9 are explained below step by step.
The controller 150 waits for transmission
of the CDMA Ranging Code from the MS 200. (That is, the
controller 150 goes into a wait state.)
The controller 150 receives and acquires
the CDMA Ranging Code.
The controller 150 determines whether or
not the reception power, frequency, and timing in the CDMA
Ranging Code are within the specified ranges. When yes is
determined, the operation goes to step S16. When no is
determined, the operation goes to step S14.
The controller 150 transmits to the MS
200 the "RNG-RSP" message containing the Continue Status.
The controller 150 waits for transmission
of the CDMA Ranging Code from the MS 200. (That is, the
controller 150 goes into a wait state.) Thereafter, the
operation goes to step S12.
In the case where the values of the CDMA
Ranging Code are within the specified ranges, the
controller 150 transmits to the MS 200 the "RNG-RSP"
message containing the Success Status.
The controller 150 allocates to the MS
200 a bandwidth necessary for transmission of the "RNG-REQ
(MAC Address, etc)" message, and transmits the "UL-MAP
(CDMA Allocation IE)" message to the MS 200.
The controller 150 waits for transmission
of the "RNG-REQ (MAC Address, etc)" message from the MS
200. (That is, the controller 150 goes into a wait state.)
The controller 150 receives the "RNG-REQ
(MAC Address, etc)" message.
The controller 150 acquires the MAC
address and message parameter of the MS 200 from the
received message. The controller 150 refers to the TLV
definition table 161 (as indicated in FIG. 5), and
interprets the message parameter. The message parameter
includes the message sizes of the "SBC-REQ" message and
the "REG-REQ" message, the time of delay occurring after
the MS 200 receives the "RNG-RSP (Basic/Primary CID, etc)"
message until the MS 200 becomes ready to transmit the
"SBC-REQ" message, and the time of delay occurring after
the MS 200 receives the "PKMv2-RSP (Key-Reply)" message
until the MS 200 becomes ready to transmit the "REG-REQ"
message. Then, the controller 150 produces the parameter
table 163 (as indicated in FIG. 5) on the basis of the
message parameter, and stores the parameter table 163 in
the storage 160.
The controller 150 allocates the Basic
CID and the Primary CID to the MS 200.
The controller 150 transmits the "RNG-RSP
(Basic/Primary CID, etc)" message to the MS 200.
The controller 150 refers to the
transmission-trigger table 162 (as indicated in FIG. 5) ,
and recognizes that the reception of the "RNG-RSP" message
realizes a transmission trigger for a message by the MS
200. Specifically, in step S23, the controller 150 resets
the value of the retransmission number counter to "0."
Thereafter, the operation goes to step S31 (in FIG. 10).
FIG. 10 is a second flow diagram indicating
operations performed by the controller in the BS. The
operations of FIG. 10 are explained below step by step.
The controller 150 starts a timer for
measuring a waiting time.
The controller 150 detects an expiration
of a time in the timer. Specifically, the controller 150
refers to the transmission-trigger table 162, and acquires
the transmission trigger ID "1" in the "RNG-RSP
(Basic/Primary CID, etc)" message transmitted in step S22.
Then, the controller 150 refers to the parameter table 163,
and acquires the time of delay "10 ms" associated with the
acquired transmission trigger ID. Subsequently, the
controller 150 compares the acquired time of delay "10 ms"
with the value of the timer, and determines the expiration
when the value of the timer becomes equal to or greater
than the time of delay.
The controller 150 allocates a bandwidth
to the MS 200. At this time, the controller 150 refers to
the parameter table 163, and acquires the message size
associated with the transmission trigger ID "1" acquired
in step S32. Then, the controller 150 allocates to the MS
200 a wireless bandwidth corresponding to the acquired
message size. Subsequently, the controller 150 transmits
the "UL-MAP (Burst Allocation)" message to the MS 200.
The controller 150 waits for transmission
of the "SBC-REQ" message from the MS 200. When the BS 100
receives the "RNG-REQ" message from the MS 200, the
operation goes to step S35. When the BS 100 receives the
"SBC-REQ" message from the MS 200, the operation goes to
step S37. In the case where the BS 100 cannot receive a
message from the MS 200, the "No Signal" state is
determined, and the operation goes to step S41 (indicated
in FIG. 11) . In the case where a CRC error occurs in a
message received from the MS 200, the operation goes to
step S45 (indicated in FIG. 11).
The controller 150 acquires the "RNG-REQ"
message.
The controller 150 retransmits to the MS
200 the "RNG-RSP" message containing the Basic/Primary CID.
Thereafter, the operation goes to step S31.
The controller 150 acquires the "SBC-REQ"
message.
The controller 150 performs negotiations
for the authentication technique and the functions in the
physical layer which are used in communications, where the
functions in the physical layer include the modulation
technique, the error-correcting coding technique, the H-
ARQ technique, and the like which are supported.
The controller 150 transmits the "SBC-
RSP" message to the MS 200. Thereafter, messages are
exchanged between the BS 100 and the MS 200 as indicated
in FIG. 7.
FIG. 11 is a third flow diagram indicating
operations performed by the controller in the BS. In FIG.
11, a sequence of error processing is indicated. The
operations of FIG. 11 are explained below step by step.
In the case where no message is
transmitted by use of the bandwidth allocated to the MS
200 for a predetermined time, the controller 150
determines that the allocated bandwidth is in the "No
Signal" state.
The controller 150 retransmits to the MS
200 the "RNG-RSP" message containing the Basic/Primary CID.
The controller 150 compares the value of
the retransmission number counter with the maximum
retransmission number (which is preset). When the value of
the retransmission number counter is smaller than the
maximum retransmission number, the operation goes to step
S44. When the value of the retransmission number counter
is equal to or greater than the maximum retransmission
number, the operation goes to step S48.
The controller 150 increments the value
of the retransmission number counter. Thereafter, the
operation goes to step S31.
The controller 150 detects occurrence of
a CRC error in the message received from the MS 200.
The controller 150 compares the value of
the retransmission number counter with the maximum
retransmission number (which is preset). When the value of
the retransmission number counter is smaller than the
maximum retransmission number, the operation goes to step
S47. When the value of the retransmission number counter
is equal to or greater than the maximum retransmission
number, the operation goes to step S48.
The controller 150 increments the value
of the retransmission number counter. Thereafter, the
operation goes to step S33.
The controller 150 transmits to the MS
200 the "RNG-RSP" message containing the Continue Status.
The controller 150 waits for transmission
of the CDMA Ranging Code from the MS 200. Thereafter, the
controller 150 acquires the CDMA Ranging Code from the MS
200.
The controller 150 determines whether or
not the reception power, frequency, and timing in the CDMA
Ranging Code are within the specified ranges. In the case
where the values of the CDMA Ranging Code are within the
specified ranges, the operation goes to step S52. In the
case where one or more of the values of the CDMA Ranging
Code are outside one or more of the specified ranges, the
operation goes to step S51.
The controller 150 transmits to the MS
200 the "RNG-RSP" message containing one or more
adjustment values for the one or more of the transmission
parameters. Thereafter, the operation goes to step S49.
The controller 150 transmits to the MS
200 the "RNG-RSP" message containing the Success Status.
The controller 150 resets the value of
the retransmission number counter to "0." Thereafter, the
operation goes to step S33.
Next, the operations performed by the controller 250
in the MS 200 are explained in detail below with reference
to flow diagrams.
FIG. 12 is a first flow diagram indicating
operations performed by the controller in the MS. FIG. 12
indicates the operations following the transmission of the
CDMA Ranging Code. The operations of FIG. 12 are explained
below step by step.
The controller 250 waits for transmission
of the "RNG-RSP" message from the BS 100.
The controller 250 acquires the "RNG-RSP"
message transmitted from the BS 100.
The controller 250 determines whether or
not the "RNG-RSP" message transmitted from the BS 100
indicates the Success Status. When yes is determined, the
operation goes to step S66. When no is determined, the
operation goes to step S64.
The controller 250 transmits the CDMA
Ranging Code.
The controller 250 waits for transmission
of the "RNG-RSP" message from the BS 100. Thereafter, the
operation goes to step S62.
The controller 250 waits for transmission
of the "UL-MAP (CDMA Allocation IE)" message from the BS
100.
The controller 250 acquires the "UL-MAP
(CDMA Allocation IE)" message transmitted from the BS 100.
The controller 250 transmits the "RNG-REQ
(MAC Address, etc)" message. Specifically, the controller
250 produces a message parameter having the same form as
the value of the type "X" in the TLV definition table 261
on the basis of the contents of the message-information
management table 263. The message parameter is constituted
by the size of the message to be transmitted, the time of
delay, and the transmission trigger ID. The size of the
message to be transmitted and the time of delay can be
acquired from the message-information management table 263,
and the transmission trigger ID can be acquired from the
transmission-trigger table 262. That is, the controller
250 searches the transmission-trigger table 262 for the
message to be transmitted corresponding to the type of the
message indicated in the column "Transmitted Message" in
the message-information management table 263, and acquires
from the transmission-trigger table 262 the transmission
trigger ID corresponding to the message to be transmitted
which is searched for.
The controller 250 waits for transmission
of the "RNG-RSP (Basic/Primary CID, etc)" message from the
BS 100. In the case where the "RNG-RSP (Basic/Primary CID,
etc)" message from the BS 100 reaches the MS 200, the
operation goes to step S72. In the case where the "UL-MAP
(Burst Allocation)" message from the BS 100 reaches the MS
200 before the "RNG-RSP (Basic/Primary CID, etc)" message
reaches the MS 200, the operation goes to step S70.
The controller 250 acquires the "UL-MAP
(Burst Allocation)" message transmitted from the BS 100.
The controller 250 retransmits the "RNG-
REQ (MAC Address, etc)" message. Thereafter, the operation
goes to step S69.
The controller 250 acquires the "RNG-RSP
(Basic/Primary CID, etc)" message transmitted from the BS
100.
The controller 250 makes preparations for
transmission of the "SBC-REQ" message. Thereafter, the
operation goes to step S81 (indicated in FIG. 13) .
FIG. 13 is a second flow diagram indicating
operations performed by the controller in the MS. The
operations of FIG. 13 are explained below step by step.
The controller 250 waits for transmission
of the "UL-MAP (Burst Allocation)" message from the BS 100.
The controller 250 acquires the "UL-MAP
(Burst Allocation)" message transmitted from the BS 100.
The controller 250 transmits the "SBC-
REQ" message to the BS 100.
The controller 250 waits for transmission
of the "SBC-RSP" message from the BS 100. When the "SBC-
RSP" message from the BS 100 reaches the MS 200, the
operation goes to step S85. When the "UL-MAP (Burst
Allocation)" message from the BS 100 reaches the MS 200,
the operation goes to step S87. Further, when the "RNG-RSP
(Continue)" message from the BS 100 reaches the MS 200,
the operation goes to step S89.
The controller 250 acquires the "SBC-RSP"
message transmitted from the BS 100.
The controller 250 waits for transmission
of the "PKMv2-RSP (EAP-Transfer: EAP Request/Identify)"
message from the BS 100. Thereafter, messages are
exchanged between the MS 200 and the BS 100 as indicated
in FIG. 7.
The controller 250 acquires the "UL-MAP
(Burst Allocation)" message transmitted from the BS 100.
The controller 250 retransmits the "SBC-
REQ" message to the BS 100. Thereafter, the operation goes
to step S84.
The controller 250 acquires the "RNG-RSP
(Continue)" message transmitted from the BS 100.
The controller 250 transmits the CDMA
Ranging Code to the BS 100.
The controller 250 waits for transmission
of the "RNG-RSP" message from the BS 100.
The controller 250 acquires the "RNG-RSP"
message transmitted from the BS 100.
The controller 250 determines whether or
not the acquired "RNG-RSP" message indicates the Success
Status. When yes is determined, the operation goes to step
S81. When no is determined, the operation goes to step S90.
As explained above, efficient bandwidth allocation
can be realized without impairing communication
reliability.
Although messages for requesting or allocating
bandwidths for transmission of the "PKM-REQ" messages are
not indicated in the above explanations on the first
embodiment, the operations similar to the operations
explained above can also be applied to the bandwidth
allocation for the "PKM-REQ" messages (e.g., the "PKMv2-
REQ (Key Request)" message).

Next, the second embodiment is explained below. The
second embodiment is applied to the cases in which an MS
transmits a message to a BS after the MS performs some
processing in response to a message from the BS, and the"
processing time of the MS cannot be evaluated in advance.
In the first embodiment, the time of delay occurring until
preparations for transmission of the message to be
transmitted from the MS are completed and the size of the
message are predetermined in the MS. However, in some type
of processing, the time of delay can vary. For example,
information for authentication is exchanged by PKM
messages. In some cases, the MS performs verification of
the validity of information contained in a message
received from the BS, generation of a key, and the like,
so that the time of delay occurring until transmission of
a subsequent message can vary.
According to the second embodiment, even in the case
where the time of delay can vary and preparations for
transmission of a message cannot be completed in a
predetermined time of delay, the processing efficiency in
bandwidth allocation for transmission of the message is
improved. Even in the above case, the first embodiment can
be applied by determining the fixed time of delay to be
the maximum delay time. However, in the case where the
first embodiment is applied as above, the determined time
of delay is too large, so that the processing delay
increases.
In order to solve the above problem, according to
the second embodiment, the BS first allocates to an MS a
Bandwidth Request CDMA Code, which is unique to the MS.
Immediately before the MS becomes ready to transmit a
subsequent message, the MS transmits to the BS the
Bandwidth Request CDMA Code as a wireless-bandwidth
request signal for requesting bandwidth allocation. When
the BS receives the Bandwidth Request CDMA Code, the BS
determines the MS on the basis of the Bandwidth Request
CDMA Code, and allocates a bandwidth through which a
message expected to be received next can be transmitted.
The message size is assumed to be known in advance by both
of the BS and the MS, for example, by informing the BS of
the message size by the MS in a similar manner to the
first embodiment.
The Bandwidth Request CDMA Code can be allocated by
the BS to the MS, for example, by using an "RNG-RSP"
message or the like. At this time, it is possible to limit
the expiration period of the allocated code to the time at
which the process for network entry of the MS receiving
the allocation is completed, for reducing the number of
codes.
In addition, the code may be allocated on a message-
by-message basis. That is, the BS can attach, to a message
to be transmitted from the BS to the MS, a Bandwidth
Request Code for requesting a bandwidth for use in
transmission of a subsequent message from the MS. Then,
the MS can use the Bandwidth Request CDMA Code for
requesting a bandwidth for use in the transmission of the
subsequent message.
The functions of the BS and the MS for realizing the
above processing are similar to the functions in the first
embodiment illustrated in FIGS. 3 and 4. However, the
second embodiment is different from the first embodiment
in the processing performed by the controller 150 in the
BS 100, the data stored in the storage 160 in the BS 100,
the processing performed by the controller 250 in the MS
200, and the data stored in the storage 260 in the MS 200.
Therefore, the features of the second embodiment which are
different from the first embodiment are explained below
with reference to FIGS. 3 and 4.
FIG. 14 is a diagram illustrating the contents of
the storage in the BS in the second embodiment. The
storage 160 in the BS 100 stores in advance the TLV
definition table 161, the transmission-trigger table 162,
and a transmitted-message-ID management table 164. In
addition, when the MS 200 is connected to the BS 100, the
parameter table 163 and a message-size management table
165 are produced by the controller 150, and stored in the
storage 160.
A TLV definition of the type "Y," as well as the TLV
definition of the type "X" (indicated in FIG. 5), is
recorded in the TLV definition table 161 indicated in FIG.
14. In the TLV definition of the type "Y," the leading
eight bits indicate the transmitted message ID, and the
subsequent 16 bits indicate the size of the message to be
transmitted (in bytes) . The transmitted message ID is an
identification number for uniquely identifying a message
transmitted from the MS 200 to the BS 100.
The controller 150 in the BS 100 recognizes the
message parameter received from the MS 200, on the basis
of the TLV definition table 161. Specifically, when the
controller 150 receives a message parameter of the type
"X," the controller 150 determines that the message
parameter is for automatic bandwidth allocation. Therefore,
the controller 150 analyzes the message parameter of the
type "X" by reference to the TLV definition table 161, and
records the transmission trigger ID, the time of delay,
and the message size in the parameter table 163.
In addition, when the controller 150 receives a
message parameter of the type "Y," the controller 150
determines that the message parameter is for bandwidth
allocation based on reception of a BW Request Code.
Therefore, the controller 150 analyzes the message
parameter of the type "Y" by reference to the TLV
definition table 161, and records the transmitted message
ID and the message size in the message-size management
table 165.
The contents of the transmission-trigger table 162
and the parameter table 163 are as indicated in FIG. 5.
The transmitted-message-ID management table 164 is a
data table for management of the transmitted message ID.
The transmitted-message-ID management table 164 has the
columns of "Transmitted Message ID" and "Message." The
identification number of each message transmitted from the
MS 200 to the BS 100 is recorded in the column
"Transmitted Message ID," and the type of the message
corresponding to the transmitted message ID is recorded in
the column "Message."
The message-size management table 165 is a data
table for management of the data sizes of all or part of
the messages transmitted from the MS 200 to the BS 100 for
each of which the time of delay is unknown and the data
size is known. The message-size management table 165 has
the columns of "Transmitted Message ID" and "Message
Size." The identification number of each message
transmitted from the MS 200 is set in the column
"Transmitted Message ID," and the data size of the
corresponding message is set in the column "Message Size."
FIG. 15 is a diagram illustrating the contents of
the storage in the MS in the second embodiment. The
storage 260 in the MS 200 stores the TLV definition table
261, the transmission-trigger table 262, and a
transmitted-message-ID management table 264. When the MS
200 is connected, the controller 250 produces a message-
information management table 263, and stores the message-
information management table 263 in the storage 260.
The structures and the contents of the TLV
definition table 261 are identical to the TLV definition
table 161 indicated in FIG. 14. The contents of the
transmission-trigger table 262 are identical to the
contents indicated in FIG. 6.
The message sizes of one or more messages for each
of which the time of delay is unknown and the data size is
known in advance, as well as the information indicated in
FIG. 6, are set in the message-information management
table 263. In the message-information management table 263,
for the one or more messages for each of which the time of
delay is unknown and the data size is known in advance,
valid data are set only in the column "Message Size," and
invalid data are set in the column "Delay Time."
The structures and the contents of the transmitted-
message-ID management table 264 are identical to the
transmitted-message-ID management table 164 indicated in
FIG. 14. '
When the above data are used, efficient bandwidth
allocation can be realized between the BS 100 and the MS
200.
FIG. 16 is a diagram indicating a sequence of
messages exchanged when the MS starts an operation for
connection to the BS in the second embodiment. In FIG. 16,
it is assumed that EAP-TLS (Extensible Authentication
Protocol Transport Layer Security) is adopted as the
authentication technique. The sequence preceding the
transmission of the "SBC-REQ" message in FIG. 16 is
similar to the first embodiment.
The messages exchanged between the BS 100 and the MS
200 are indicated in FIG. 16. In FIG. 16, the exchanged
messages are indicated by arrow lines, the types of the
messages are indicated above the arrow lines, and the data
contained in the messages are indicated in parentheses
following the types of the messages. In addition, the
signals and messages for requesting and allocating a
bandwidth are indicated by dashed lines, and the main
messages for exchanging information on authentication and
the like between the MS 200 and the BS 100 are indicated
by solid lines.
Further, the curved lines shown on the BS side with
arrows each indicate processing for allocation of a
bandwidth, and extend from a message causing the
processing for bandwidth allocation to a message informing
the MS 200 of details of the bandwidth allocation. In
particular, the curved dashed lines indicate automatic
bandwidth allocation in consideration of the time of delay,
where the automatic bandwidth allocation is realized by
the function of allocating a bandwidth according to the
first embodiment. On the other hand, the curved solid
lines indicate bandwidth allocation based on reception of
the BW Request Code, which is realized by the function of
allocating a bandwidth provided according to the second
embodiment.
As indicated in FIG. 16, after the BS 100 transmits
the "SBC-RSP" message, the BS 100 transmits a "PKMv2-RSP
(EAP-Transfer: EAP Request/Identify)" message to the MS
200 in order to start an authentication sequence. When the
MS 200 receives the "PKMv2-RSP (EAP-Transfer: EAP
Request/Identify)" message, and a predetermined time
elapses after the transmission of the "PKMv2-RSP (EAP-
Transfer: EAP Request/Identify)" message, the B*S 100
allocates to the MS 200 a bandwidth for transmission, from
the MS 200 to the BS 100, of a "PKMv2-REQ (EAP-Transfer:
EAP-Response/Identify(MylD))" message containing an NAI
(Network Access Identifier) as an identification of the MS
200. Similar to the first embodiment, the BS 100 is
informed of the predetermined time by the MS 200 using the
"RNG-REQ (MAC Address, etc)" message, and records the
predetermined time in the parameter table 163.
Alternatively, the above time of delay as a parameter
unique to the system may be recorded in advance in the
parameter table 163.
Incidentally, the "PKMv2-REQ" message contains
information for processing in a protocol layer which is
higher than the "SBC-REQ" message and the "REG-REQ"
message, including authentication information. Therefore,
it is preferable that the processing time allowed for the
MS 200 becoming ready to transmit the "PKMv2-REQ" message
be greater than the processing time allowed for the MS 200
becoming ready to transmit the "SBC-REQ" message or the
"REG-REQ" message.
When the MS 200 receives the "PKMv2-RSP (EAP-
transmits to the BS 100 the "PKMv2-REQ (EAP-Transfer: EAP-
Response/Identify(MylD))" message containing the NAI
(Network Access Identifier) of the MS 200 by using an
automatically allocated wireless bandwidth. At this time,
the NAI has, for example, the form as "user-
name@service_provider.com". The NAI is transferred through
the BS 100 to an authentication server (not shown) ,
although explanations on the exchange of messages between
the BS 100 and the authentication server are not included
in this specification.
The BS 100 starts TLS (Transport Layer Security)
authentication by transmitting a "PKMv2-RSP EAP-Transfer
(EAP-Request/TLS Start)" message to the MS 200. At this
time, the BS 100 allocates to the MS 200 a wireless
bandwidth for transmission of an "EAP-Response/TLS Client
Hello" message by the MS 200 in a similar manner to the
aforementioned operation after the transmission of the
"EAP Request/Identify" message. When the MS 200 receives
the "PKMv2-RSP EAP-Transfer (EAP-Request/TLS Start)"
message, the MS 200 transmits a "PKMv2-REQ EAP-Transfer
(EAP-Response/TLS Client Hello)" message to the BS 100 by
using the automatically allocated bandwidth. The "PKMv2-
REQ EAP-Transfer (EAP-Response/TLS Client Hello)" message
contains a TLS version, a session ID, a random number,
candidate cipher algorithms, and the like.
Subsequently, the BS 100 transmits to the MS 200 a
"PKMv2-RSP EAP-Transfer (EAP-Request/TLS Server Hello,
Server Certificate, . . . ) " message containing a selected
TLS version, a session ID, a random number, candidate
cipher algorithms, a Server Certificate, and the like.
When the MS 200 receives the Server Certificate, it
is necessary for the MS 200 to verify the validity of the
Server Certificate before transmission of a response
message. However, the verification time of the Server
Certificate is uncertain. Therefore, the BS 100 allocates
a bandwidth after receiving the Bandwidth Request CDMA
Code from the MS 200, instead of automatically allocating
a bandwidth for transmission of a response message from
the MS 200. As mentioned before, the Bandwidth Request
CDMA Code is uniquely allocated to the MS 200. Therefore,
when the BS 100 receives the Bandwidth Request CDMA Code,
the BS 100 can determine which MS 200 transmits the
Bandwidth Request CDMA Code. When the verification of the
Server Certificate is completed, the MS 200 transmits the
allocated Bandwidth Request CDMA Code to the BS 100 before
preparations for transmission of a "PKMv2-REQ EAP-Transfer
(EAP-Response/TLS Client Certificate . . .)" message are
completed.
When the BS 100 receives the Bandwidth Request CDMA
Code, the BS 100 allocates to the MS 200 a bandwidth for
transmission of the EAP-Response/TLS Client Certificate
from the MS 200. At this time, the bandwidth is determined
according to the message size recorded in the message-size
management table 165 in correspondence with the message ID
of the "PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client
Certificate . . .)" message. When the bandwidth is
allocated to the MS 200, the BS 100 transmits a "UL-MAP
(Burst Allocation)" message to the MS 200. When the MS 200
receives the allocation of the bandwidth, the MS 200
transmits to the BS 100 the "PKMv2-REQ EAP-Transfer (EAP-
Response/TLS Client Certificate . . .)" message containing
the Client Certificate and the like by use of the
allocated bandwidth.
In the following operations, the request and
allocation of a bandwidth are performed by using either of
the manner in which the bandwidth is automatically
allocated in consideration of the time of delay as
explained for the first embodiment and the manner in which
the bandwidth is allocated on the basis of the Bandwidth
Request CDMA Code, where the latter manner is newly
provided according to the second embodiment. Therefore, in
the following explanations on the bandwidth allocation
during the EAP exchange using PKM messages, only the used
manner of the bandwidth allocation is indicated, and
explanations on the exchange of messages and signals for
the bandwidth allocation are not indicated.
When the BS 100 receives the "PKMv2-REQ EAP-Transfer
(EAP-Response/TLS Client Certificate . . .)" message, the
BS 100 performs authentication of the Client Certificate.
When the authentication succeeds, the BS 100 transmits to
the MS 200 a "PKMv2-RSP EAP-Transfer (EAP-Request/TLS
Change Cipher Spec)" message together with information
indicating the success of the authentication, the cipher
algorithm, and the like. At this time, the BS 100
automatically allocates a bandwidth, in consideration of
the time of delay, for transmission of a "PKMv2-REQ EAP-
Transfer (EAP-Response/TLS)" message from the MS 200.
When the MS 200 receives the EAP-Request/TLS Change
Cipher Spec, the MS 200 transmits to the BS 100 the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS)" message
through the allocated wireless bandwidth in response to
the EAP-Request/TLS Change Cipher Spec.
When the BS 100 receives the "PKMv2-REQ EAP-Transfer
(EAP-Response/TLS)" message, the BS 100 transmits to the
MS 200 a "PKMv2-RSP (EAP-Transfer: EAP-Success)" message
containing a Master Secret Key (MSK). At this time, the BS
100 generates an AK (Authentication Key) from the MSK, and
further generates a KEK (Key Encryption Key) and a
CMAC_Key from the AK.
When the MS 200 receives the "PKMv2-RSP (EAP-
Transfer: EAP-Success)" message, the MS 200 generates the
AK from the MSK, and the KEK and the CMAC_Key from the AK.
After the BS 100 transmits the "PKMv2-RSP (EAP-
Transfer: EAP-Success)" message and generates the AK, KEK
and CMAC_Key, the BS 100 transmits to the MS 200 a "PKMv2-
RSP (SA-TEK-Challenge)" message, which is protected by the
generated CMAC_Key. That is, a result (CMAC) of a hash
calculation of the contents of the PKM-RSP message by use
of the CMAC_Key is attached to the PKM-RSP message so that
falsification by somebody other than the BS 100 and the MS
200, which share the CMAC_Key, can be detected.
When the MS 200 receives the "PKMv2-RSP (SA-TEK-
Challenge)" message, the MS 200 compares the CMAC attached
to the PKM-RSP message with a result (CMAC) of a hash
calculation of the contents of the received PKM-RSP
message for confirming identicalness. When the CMACs are
identical, the MS 200 can confirm that the BS 100 and the
MS 200 have the identical CMAC_Keys. When the processing
for the confirmation is completed, the MS 200 receives
bandwidth allocation based on the Bandwidth Request CDMA
Code. Then, the MS 200 transmits to the BS 100 a "PKMv2-
REQ (SA-TEK-Request)" message by use of the allocated
wireless bandwidth in response to the "PKMv2-RSP (SA-TEK-
Challenge)" message, where the "PKMv2-REQ (SA-TEK-
Request)" message is protected with the CMAC.
When the BS 100 receives the "PKMv2-REQ (SA-TEK-
Request)" message, the BS 100 performs CMAC confirmation
processing in a similar manner to the MS 200 for
confirming that the BS 100 and the MS 200 have the
identical CMAC_Keys. Then, the BS 100 transmits to the MS
200 a "PKMv2-RSP (SA-TEK-Response)" message in response to
the "PKMv2-REQ (SA-TEK-Request)" message.
When the MS 200 receives the "PKMv2-RSP (SA-TEK-
Response)" message, the MS 200 confirms that the SA-TEK-
Request is normally received by the BS 100. When the MS
200 confirms that the BS 100 and the MS 200 have the
identical CMACs, the MS 200 receives bandwidth allocation
based on the Bandwidth Request CDMA Code. Then, the MS 200
transmits to the BS 100 a "PKMv2-REQ (Key Request)"
message for requesting an issue of an encryption key TEK
(Traffic Encryption Key) for use in encryption of user
data.
When the BS 100 receives the "PKMv2-REQ (Key
Request)" message, the BS 100 randomly generates the TEK,
encrypts the TEK with the KEK, inserts the encrypted TEK
into a Key-Reply, and transmits "PKMv2-RSP (Key-Reply)"
message to the MS 200. At this time, the BS 100 performs
automatic bandwidth allocation in consideration of the
time of delay for transmission of the "REG-REQ" message
from the MS 200.
When the MS 200 receives the "PKMv2-REQ (Key-Reply)"
message, the BS 100 transmits the "REG-REQ" message to the
BS 100, and continues the Network Entry process.
Although, in the example of FIG. 16, the message
containing authentication information is indicated as an
example for which a bandwidth request by use of the
Bandwidth Request CDMA Code is preferable (in other words,
an example of which the timing of transmission of a
message from the MS 200 is irregular), the bandwidth
request by use of the Bandwidth Request CDMA can be
applied to other messages.
FIG. 17 is a state transition diagram of the BS. FIG.
17 indicates state transitions of the BS 100 in the
authentication processing performed after the state ST1,
in which the BS 100 waits for reception of the "SBC-REQ"
message. When the BS 100 in the state ST1 receives the
"SBC-REQ" message, the BS 100 transmits the "SBC-RSP"
message and other messages, and performs automatic
bandwidth allocation in consideration of the time of delay.
Thereafter, the state of the BS 100 transitions from the
state ST1 to the state ST2, in which the BS 100 waits for
reception of the "PKMv2-REQ (EAP-Transfer: EAP-
Response/Identify(MyID))" message.
When the BS 100 in the state ST2 receives the
"PKMv2-REQ (EAP-Transfer: EAP-Response/Identify(MyID))"
message, the BS 100 performs automatic bandwidth
allocation in consideration of the time of delay, and
thereafter the state of the BS 100 transitions from the
state ST2 to the state ST3, in which the BS 100 waits for
reception of the "PKMv2-REQ EAP-Transfer (EAP-Response/TLS
Client Hello)" message.
When the BS 100 in the state ST3 receives the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client Hello)"
message, the BS 100 transmits the "PKMv2-RSP EAP-Transfer
(EAP-Request/TLS Server Hello)", and thereafter the state
of the BS 100 transitions from the state ST3 to the state
ST4, in which the BS 100 waits for reception of the
Bandwidth Request CDMA Code.
When the BS 100 in the state ST4 receives the
Bandwidth Request CDMA Code, the BS 100 performs bandwidth
allocation to the MS 200, and thereafter the state of the
BS 100 transitions from the state ST4 to the state ST5, in
which the BS 100 waits for reception of the "PKMv2-REQ
EAP-Transfer (EAP-Response/TLS Client Certificate . . .)"
message.
When the BS 100 in the state ST5 receives the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client
Certificate . . . ) " message, the BS 100 performs
authentication of the Client Certificate, transmits the
"PKMv2-RSP EAP-Transfer (EAP-Request/TLS Change Cipher
Spec)" message, and performs automatic bandwidth
allocation in consideration of the time of delay.
Thereafter, the state of the BS 100 transitions from the
state ST5 to the state ST6, in which the BS 100 waits for
reception of the "PKMv2-REQ EAP-Transfer (EAP-
Response/TLS)" message.
When the BS 100 in the state ST6 receives the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS)" message, the
BS 100 performs processing for the transmission of the
"PKMv2-RSP (EAP-Transfer: EAP-Success)" message and other
processing, and thereafter the state of the BS 100
transitions from the state ST6 to the state ST7, in which
the BS 100 waits for reception of the Bandwidth Request
CDMA Code.
When the BS 100 in the state ST7 receives the
Bandwidth Request CDMA Code, the BS 100 performs bandwidth
allocation to the MS 200, and thereafter the state of the
BS 100 transitions from the state ST7 to the state ST8, in
which the BS 100 waits for reception of the "PKMv2-REQ
(SA-TEK-Request)" message.
When the BS 100 in the state ST8 receives the
"PKMv2-REQ (SA-TEK-Request)" message, the BS 100 performs
the CMAC confirmation processing and processing for
transmission of the "PKMv2-RSP (SA-TEK-Response)" message.
Thereafter, the state of the BS 100 transitions from the
state ST8 to the state ST9, in which the BS 100 waits for
reception of the Bandwidth Request CDMA Code.
When the BS 100 in the state ST9 receives the
Bandwidth Request CDMA Code, the BS 100 performs bandwidth
allocation to the MS 200, and thereafter the state of the
BS 100 transitions from the state ST9 to the state ST10,
in which the BS 100 waits for reception of the "PKMv2-REQ
(Key Request)" message.
When the BS 100 in the state ST10 receives the
"PKMv2-REQ (Key Request)" message, the BS 100 generates
the TEK, transmits the "PKMv2-RSP (Key-Reply)" message,
and performs automatic bandwidth allocation in
consideration of the time of delay. Thereafter, the state
of the BS 100 transitions from the state ST10 to the state
ST11, in which the BS 100 waits for reception of the "REG-
REQ" message.
Next, the processing sequences in the controller 150
in the BS 100 and the controller 250 in the MS 200
according to the second embodiment are explained below.
FIG. 18 is a flow diagram indicating operations
performed by the controller in the BS in the second
embodiment. FIG. 18 indicates the processing sequence from
the operation of waiting for reception of the "PKMv2-REQ
EAP-Transfer (EAP-Response/TLS Client Hello)" message to
the operation of waiting for reception of the "PKMv2-REQ
EAP-Transfer (EAP-Response/TLS Client Certificate . . ..)"
message. The operations of FIG. 18 are explained below
step by step.
The controller 150 waits for
transmission of the "PKMv2-REQ EAP-Transfer (EAP-
Response/TLS Client Hello)" message from the MS 200.
When the controller 150 receives the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client Hello)"
message, the controller 150 transmits the "PKMv2-RSP EAP-
Transfer (EAP-Request/TLS Server Hello)" message to the MS
200.
The controller 150 waits for
transmission of the Bandwidth Request CDMA Code from the
MS 200.
The controller 150 acquires the
Bandwidth Request CDMA Code transmitted from the MS 200.
When the controller 150 recognizes, on
the basis of the Bandwidth Request CDMA Code, that the MS
200 issues a request for bandwidth allocation, the
controller 150 determines the message ID of the the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client
Certificate . . . ) " message by reference to the
transmitted-message-ID management table 164, where the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client
Certificate . . . ) " message is the message which is to be
received next during the message exchange with the MS 200.
In the example of FIG. 14, the message ID of the above
message is "1." Subsequently, the controller 150 refers to
the message-size management table 165, and acquires the
message size corresponding to the message ID "1." Further,
the controller 150 allocates to the MS 200 a bandwidth
corresponding to the acquired message size, and transmits
to the MS 200 the "UL-MAP (Burst Allocation)" message,
which indicates the allocated bandwidth.
The controller 150 goes into the state
in which the controller 150 waits for reception of the the
"PKMv2-REQ EAP-Transfer (EAP-Response/TLS Client
Certificate . . .)" message from the MS 200.
FIG. 19 is a flow diagram indicating operations
performed by the controller in the MS in the second
embodiment. FIG. 19 indicates the processing sequence from
the operation of waiting for reception of the "PKMv2-RSP"
message containing the server certificate to the operation
of reception of the next "PKMv2-RSP" message. The
operations of FIG. 19 are explained below step by step.
The controller 250 waits for
transmission of the "PKMv2-RSP EAP-Transfer (EAP-
transmission of the "PKMv2-RSP EAP-Transfer (EAP-
Request/TLS Server Hello, Server Certificate, . . .)"
message from the BS 100.
The controller 250 acquires the "PKMv2-
RSP EAP-Transfer (EAP-Request/TLS Server Hello, Server
Certificate, . . .)" message transmitted from the BS 100.
The controller 250 makes the message
exchange process enter a state in which the message
exchange process waits for completion of preparations for
transmission of the next message.
The controller 250 verifies the
effectiveness of the Server Certificate by a process
different from the message exchange process. When the
verification is completed, the controller 250 makes the
message exchange process complete the preparations for
transmission of the "PKMv2-REQ EAP-Transfer (EAP-
Response/TLS Client Certificate . . .)" message.
The controller 250 transmits the
Bandwidth Request CDMA Code to the BS 100.
The controller 250 waits for bandwidth
allocation by the BS 100.
The controller 250 acquires the "UL-MAP
(Burst Allocation)" message being transmitted from the BS
100 and indicating the bandwidth allocation.
The controller 250 transmits the "PKMv2-
REQ EAP-Transfer (EAP-Response/TLS Client
Certificate . . .)" message to the BS 100.
transmission of the "PKMv2-RSP EAP-Transfer (EAP-
Request/TLS Change Cipher Spec)" message from the BS 100.
As explained above, even in the case where the time
of delay in the MS 200 varies, the bandwidth allocation
can be realized by a smaller number of message exchanges
than the conventional message exchange process.

The third embodiment is a variation of the first
embodiment. According to the third embodiment, the BS 100
holds default values of the time of delay and the message
size of a message to be transmitted from the MS, and
automatically allocates a bandwidth in consideration of
the time of delay on the basis of the default values
unless the MS informs the BS of a message parameter unique
to the MS. When the BS is informed by the MS of a message
parameter unique to the MS, the BS 100 automatically
allocates a bandwidth in consideration of the time of
delay on the basis of the message parameter.
The functions of the BS and the MS for realizing the
above processing are similar to the functions in the first
embodiment illustrated in FIGS. 3 and 4. However, the
third embodiment is different from the first embodiment in
the processing performed by the controller 150 in the BS
100, the data stored in the storage 160 in the BS 100, and
the processing performed by the controller 250 in the MS
200. Therefore, the features of the third embodiment which
are different from the first embodiment are explained
below with reference to FIGS. 3 and 4.
FIG. 20 is a diagram illustrating the contents of
the storage in the BS in the third embodiment. The storage
160 in the BS 100 stores in advance the TLV definition
table 161, the transmission-trigger table 162, a default
parameter table 163a, and an MS management table 167. In
addition, when a message parameter is transmitted from the
MS 200, the controller 150 produces MS-specific parameter
tables 166, 166a, 166b, . . . for respectively different
MSs, and stores the parameter tables 166, 166a, 166b, . . .
in the storage 160.
The contents of the TLV definition table 161 and the
transmission-trigger table 162 are as indicated in FIG. 5.
The default parameter table 163a is a data table
indicating default values of the time of delay and the
message size of each message transmitted uplink from the
MS. The default parameter table 163a has the same data
structure as the parameter table 163 indicated in FIG. 5.
However, the values in the default parameter table 163a
are set in advance of the start of the system operation,
while the values indicated by the message parameter
transmitted from the MS 200 are set in the parameter table
163 in the first embodiment.
The MS-specific parameter tables 166 are provided
for the respective MSs, and identification numbers (MSIDs)
for uniquely identifying the respective MSs are set in the
for uniquely identifying the respective MSs are set in-the
parameter tables 166. In addition, each MS-specific
parameter table 166 has the columns of "Transmission
Trigger ID," "Delay Time," and "Message Size." The value
of the transmission trigger ID in the message parameter
transmitted from the MS indicated by each MSID is set in
the column "Transmission Trigger ID," the value of the
time of delay in the message parameter transmitted from
the MS indicated by each MSID is set in the column "Delay
Time," and the value of the message size in the message
parameter transmitted from the MS indicated by each MSID
is set in the column "Message Size."
The MS management table 167 is a data table which
indicates which of the default parameter table 163a and
the MS-specific parameter table corresponding to the MSID
of each MS is to be used for the MS connected to the BS
100. The MS management table 167 has the columns of "MSID"
and "Parameter Table." The identification number (MSID) of
each MS which is connected to the BS 100 is recorded in
the column "MSID," and information indicating which of the
default parameter table and the MS-specific parameter
table is to be used for the MS indicated by each MSID is
set
a message parameter from the MS, and the controller 150
produces the MS-specific parameter table 166 corresponding
to the MS, the controller 150 updates the value in the
column "Parameter Table" corresponding to the MSID of the
MS to "MS-specific Parameter Table."
Next, processing for allocating a time period
according to the third embodiment is explained below.
FIG. 21 is a diagram indicating a sequence of
messages exchanged when the MS starts an operation for
connection to the BS in the third embodiment.
As indicated in FIG. 21, the BS 100 inserts the
default size of a message to be transmitted from the MS
200, the default time of delay in allocation of a wireless
resource, and other information, into the "UCD (Uplink
Channel Descriptor)" message, which is periodically
broadcast by the BS 100. Specifically, the controller 150
refers to the default parameter table 163a, and acquires
the transmission trigger ID, the time of delay, and the
message size for each message for which automatic
bandwidth allocation is to be performed. Then, the
controller 150 generates a message parameter 21 in
accordance with the definition of the type "X" indicated
in the TLV definition table 161, inserts the generated
message parameter 21 into the "UCD" message, and transmits
broadcast the "UCD" message to the MS 200 and the like.
When the MS 200 receives the "UCD" message, the MS
200 compares the values in the message parameter 21 of
accordance with the definition of the type "X" indicated
in the TLV definition table 161, inserts the generated
message parameter 21 into the "UCD" message, and transmits
broadcast the "UCD" message to the MS 200 and the like.
When the MS 200 receives the "UCD" message, the MS
200 compares the values in the message parameter 21 of
which the MS 200 is informed, with the corresponding
values held by the MS 200 in the message-information
management table 263 (as indicated in FIG. 6). In the case
where the compared values are not identical, the MS 200
informs the BS 100 of the corresponding parameter values
held by the MS 200 as the message parameter 22, as in the
first embodiment. Specifically, the controller 250 in the
MS 200 transmits to the BS 100 the "RNG-REQ (MAC Address,
etc)" message containing the message parameter 22, which
indicates the corresponding values in the message-
information management table 263.
The controller 150 in the BS 100 produces the MS-
specific parameter table 166 by use of the value of the
message parameter 22 of which the BS 100 is informed, and
stores the MS-specific parameter table 166 in the storage
160. In addition, the controller 150 changes the value in
the column "Parameter Table" corresponding to the MSID of
the MS 200 in the MS management table 167 to "MS-specific
Parameter Table."
Thereafter, when the controller 150 in the BS 100
transmits to the MS 200 a message which is set in the
transmission-trigger table 162 as a transmission trigger,
the controller 150 first refers to the MS management table
167, and determines, on the basis of the MS management
table 167, which of the default parameter table 163a and
the MS-specific parameter table is to be used for the MS
200. In the case where the MS-specific parameter table is
to be used for the MS 200, the controller 150 refers to
the MS-specific parameter table corresponding to the MSID
of the MS 200, and acquires the time of delay and the
message size of a message to be transmitted from the MS
200 after the transmission of the message as the
transmission trigger. After the acquired time of delay
elapses, the controller 150 allocates to the MS 200 a
wireless bandwidth corresponding to the message size. The
MS 200 is informed of the allocated bandwidth by the "UL-
MAP (Burst Allocation)" message.
Next, processing performed by the controller 250 in
the MS 200 according to the third embodiment is explained
in detail below.
FIG. 22 is a flow diagram indicating operations
performed by the MS when the MS receives a "UCD" message.
The operations of FIG. 22 are explained below step by step.
The controller 250 waits for
transmission of the "UCD (Size of Messages, delay)"
message from the BS 100.
compared parameters are not identical, the operation goes
to step S125.
The controller 250 sets a parameter flag
to "0," and thereafter the processing is completed.
The controller 250 sets a parameter flag
to "1," and thereafter the processing is completed.
As explained above, a value is set in the parameter
flag. Thereafter, when the "RNG-REQ (MAC Address, etc)"
message is transmitted, it is determined whether or not
the message parameter 22 is to be transmitted, on the
basis of the value of the parameter flag.
FIG. 23 is a flow diagram indicating operations
performed by the MS after the MS transmits the CDMA
Ranging Code until the MS transmits the "SBC-REQ" message.
The operations of FIG. 23 are explained below step by step.
The controller 250 waits for
transmission of the "RNG-RSP" message from the BS 100.
The controller 250 acquires the "RNG-
RSP" message transmitted from the BS 100.
The controller 250 determines whether or
not the "RNG-RSP" message indicates the Success Status.
When yes is determined, the operation goes to step S136.
When no is determined, the operation goes to step S134.
The controller 250 transmits the CDMA
Ranging Code.
The controller 250 waits for
transmission of the "RNG-RSP" message from the BS 100, and
thereafter the operation goes to step S132.
The controller 250 waits for
transmission of the "UL-MAP (CDMA Allocation IE)" message
from the BS 100.
The controller 250 acquires the "UL-MAP
(CDMA Allocation IE)" message transmitted from the BS 100.
The controller 250 determines whether or
not the value of the parameter flag is "1." When the
parameter flag is "1," the operation goes to step S139.
When the parameter flag is "0," the operation goes to step
S140.
The controller 250 transmits the "RNG-
REQ (MAC Address, etc)" message containing the message
parameter, and thereafter the operation goes to step S141.
The controller 250 transmits the "RNG-
REQ (MAC Address, etc)" message not containing the message
parameter.
The controller 250 waits for
transmission of the "RNG-RSP (Basic/Primary CID, etc)"
message from the BS 100. When the "RNG-RSP (Basic/Primary
CID, etc)" message transmitted from the BS 100 reaches the
MS 200, the operation goes to step S144. In addition, when
the "UL-MAP (Burst Allocation)" message reaches the MS 200
before the "RNG-RSP (Basic/Primary CID, etc)" message
reaches the MS 200, the operation goes to step S142.
The controller 250 acquires the "UL-MAP
(Burst Allocation)" message transmitted from the BS 100.
The controller 250 retransmits the "RNG-
REQ (MAC Address, etc)" message containing the message
parameter, and thereafter the operation goes to step S141.
The controller 250 acquires the "RNG-RSP
(Basic/Primary CID, etc)" message transmitted from the BS
100.
The controller 250 makes preparations
for transmission of the "SBC-REQ" message.
The controller 250 waits for
transmission of the "UL-MAP (Burst Allocation)" message
from the BS 100.
The controller 250 acquires the "UL-MAP
(Burst Allocation)" message transmitted from the BS 100.
The controller 250 transmits the "SBC-
REQ" message to the BS 100.
The controller 250 waits for
transmission of the "SBC-RSP" message from the BS 100.
The sequence of operations performed by the
controller 150 in the BS 100 in the third embodiment is
almost similar to the sequence of operations indicated in
FIGS. 9 to 11. However, the third embodiment is different
from the first embodiment in the operations in steps S20,
S32, and S33. In step S20, the controller 150 acquires the
message parameter in the case where the received message
contains the message parameter. The controller 150 refers
to the TLV definition table 161 (as indicated in FIG. 20),
analyzes the message parameter, produces an MS-specific
parameter table on the basis of the message parameter, and
stores the MS-specific parameter table in the storage 160.
In addition, the controller 150 changes the value in the
column "Parameter Table" corresponding to the MSID of the
MS 200 in the MS management table 167 to "MS-specific
Parameter Table." In the case where the received message
does not contain the message parameter, the controller 150
does not perform processing such as data update in the
storage 160.
The time of delay which is used in the comparison
for detecting the time expiration in step S32 in FIG. 10
is the time of delay which is set in the MS-specific
parameter table for the MS 200 when the MS-specific
parameter table for the MS 200 is already produced, and is
the time of delay which is set in the default parameter
table 163a when the MS-specific parameter table for the MS
200 is not yet produced. In addition, the bandwidth
allocated in step S33 is determined on the basis of the
message size which is set in the MS-specific parameter
table for the MS 200 when the MS-specific parameter table
for the MS 200 is already produced, and is the message
size which is set in the default parameter table 163a when
the MS-specific parameter table for the MS 200 is not yet
produced.
As explained above, the message parameter can be
transmitted from the MS 200 to the BS 100 only in the case
where the time of delay and the message size which are set
as default values in the BS 100 are not identical to the
values which are set in the MS 200. In addition, since the
default values which are set in the BS 100 are broadcast
from the BS 100, it is possible to effectively use the
wireless resource.
Further, the default value of the message size of
each of the "SBC-REQ" message and the "REG-REQ" message
and the default value of the time of delay occurring until
transmission of each of the "SBC-REQ" message and the
"REG-REQ" message after reception of the "RNG-RSP" message
or the "PKM-RSP" message may also be stored in the MS 200
as well as the BS 100. In this case, the default parameter
table 163a as indicated in FIG. 20 is also stored in
advance in the storage 260 in the MS 200.
In the case where the default values are held in
both of the BS 100 and the MS 200, it is unnecessary to
insert the message parameter 21 in the "UCD" message which
is broadcast from the BS 100. The MS 200 inserts the
message parameter 22 in the "RNG-REQ (MAC Address, etc)"
message and transmits the "RNG-REQ (MAC Address, etc)"
message to the BS 100 only in the case where the default
values are not identical to the values recorded in the
message-information management table 263 (as indicated in
FIG. 6).
The functions of processing performed by the
controller 150 in the BS 100 and the controller 250 in the
MS 200 as explained above are realized by computers. In
this case, a program describing details of processing for
realizing the functions which each of the controller 150
and the controller 250 should have is provided. When a
computer executes the program, the processing functions of
one of the controller 150 and the controller 250 can be
realized on the computer.
The program describing the details of the processing
can be stored in a recording medium which can be read by
the computer. The recording medium may be a magnetic
recording device, an optical disk, an optical magnetic
recording medium, a semiconductor memory, or the like. The
magnetic recording device may be a hard disk drive (HDD),
a flexible disk (FD), a magnetic tape (MT) , or the like.
The optical disk may be a DVD (Digital Versatile Disk) , a
DVD-RAM (Random Access Memory), a CD-ROM (Compact Disk-
Read Only Memory), a CD-R (Recordable)/RW (Rewritable), or
the like. The optical magnetic recording medium may be an
MO (Magneto-Optical Disk) or the like.
In order to put each program into the market, for
example, it is possible to sell a portable recording
medium such as a DVD or a CD-ROM in which the program is
recorded. Alternatively, it is possible to store the
program in a storage device belonging to a server computer,
and transfer the program to another computer through a
network.
The computer which should execute the program stores
the program in a storage device belonging to the computer,
where the program is originally recorded in, for example,
a portable recording medium, or is initially transferred
from the server computer. The computer reads the program
from the storage device, and performs processing in
accordance with the program. Alternatively, the computer
may directly read the program from the portable recording
medium for performing processing in accordance with the
program. Further alternatively, the computer can
sequentially execute processing in accordance with each
portion of the program every time the portion of the
program is transferred from the server computer.
The present invention is not limited to the above
embodiments, the embodiments can be variously modified
within the scope of the invention.
The foregoing is considered as illustrative only of
the principle of the present invention. Further, since
numerous modifications and changes will readily occur to
those skilled in the art, it is not desired to limit the
invention to the exact construction and applications shown
and described, and accordingly, all suitable modifications
and equivalents may be regarded as falling within the
scope of the invention in the appended claims and their
equivalents.
Description of Reference Numerals
1 wireless terminal
1a message-parameter transmission means
1b message transmission means
2 wireless base station
2a trigger-message transmission means
2b bandwidth allocation means
2c allocation-information transmission means
3 message parameter
4 trigger message
5 allocation information
6 message to be transmitted
WE CLAIM
1. A message exchange method for communication
between a wireless base station and a wireless terminal,
comprising:
transmitting a message parameter from said wireless
terminal to said wireless base station, where the message
parameter includes identification information identifying
a trigger message and a message size indicating a data
length of a message to be transmitted from the wireless
terminal to the wireless base station, and the trigger
message is a message to trigger transmission of the
message to be transmitted;
transmitting said trigger message from said wireless
base station to the wireless terminal, and thereafter
allocating a wireless bandwidth corresponding to said
message size of the message to be transmitted, to said
wireless terminal by said wireless base station;
transmitting allocation information indicating the
allocated wireless bandwidth from said wireless base
station to said wireless terminal; and
transmitting said message to be transmitted, from
said wireless terminal to said wireless base station by
using said wireless bandwidth indicated by said allocation
information.
2. The message exchange method according to claim 1,
wherein:
said wireless terminal inserts in said message
parameter a time of delay occurring after reception of
said trigger message until completion of preparations for
transmission of said message to be transmitted, when the
wireless terminal transmits the message parameter to said
wireless base station; and
the wireless base station allocates a wireless
bandwidth to the wireless terminal after said time' of
delay elapses since the wireless base station transmits
the trigger message.
3. The message exchange method according to claim 2,
wherein said wireless terminal transmits said message
parameter to said wireless base station only in the case
where said message size, said time of delay, or a
combination thereof of said message to be transmitted is
not identical to respective default values of the message
size and the time of delay which are respectively
predetermined.
4. The message exchange method according to claim 3,
wherein said wireless base station transmits to said
wireless terminal said default values of the message size
and the time of delay of said message to be transmitted.
5. The message exchange method according to claim 4,
wherein said wireless base station transmits by
broadcasting to said wireless terminal said default values
of the message size and the time of delay.
6. The message exchange method according to claim 1,
wherein, in the case where said message to be transmitted
is not transmitted from said wireless terminal through the
allocated wireless bandwidth after said allocation
information is transmitted to the wireless terminal, said
wireless base station retransmits said trigger message,
reallocates a wireless bandwidth to the wireless terminal,
and transmits to the wireless terminal allocation
information indicating the reallocated wireless bandwidth.
7. The message exchange method according to claim 6,
wherein:
said wireless terminal inserts in said message
parameter a time of delay occurring after reception of
said trigger message until completion of preparations for
transmission of said message to be transmitted, when the
wireless terminal transmits the message parameter to said
wireless base station;
the wireless base station allocates a wireless
bandwidth to the wireless terminal after said time of
delay elapses since the wireless base station transmits
the trigger message; and
bandwidth to the wireless terminal after said time of
delay elapses since the wireless base station retransmits
the trigger message.
8. The message exchange method according to claim 1,
wherein said wireless base station reallocates a wireless
bandwidth to said wireless terminal, and transmits to the
wireless terminal allocation information indicating the
reallocated wireless bandwidth, in the case where the
wireless base station detects an error in said message to
be transmitted after the message to be transmitted is
transmitted from the wireless terminal.
9. The message exchange method according to claim 1,
wherein said wireless base station performs processing for
adjustment of a transmission parameter of said wireless
terminal in the case where said message to be transmitted
is not transmitted from the wireless terminal through the
allocated wireless bandwidth after said allocation
information is transmitted to the wireless terminal, or in
the case where the wireless base station detects an error
in the message to be transmitted after the message to be
transmitted is transmitted from the wireless terminal.
10. The message exchange method according to claim 1,
wherein
said wireless base station retransmits said trigger
said wireless base station retransmits said trigger
message, reallocates a wireless bandwidth to said wireless
terminal, and transmits to the wireless terminal
allocation information indicating the reallocated wireless
bandwidth in the case where said message to be transmitted
is not transmitted from the wireless terminal through the
allocated wireless bandwidth after said allocation
information is transmitted to the wireless terminal;
the wireless base station reallocates a wireless
bandwidth to the wireless terminal, and transmits to the
wireless terminal allocation information indicating the
reallocated wireless bandwidth in the case where the
wireless base station detects an error in the message to
be transmitted after the message to be transmitted is
transmitted from the wireless terminal; and
the wireless base station sets the number of
retransmissions of allocation information in a
retransmission number counter, and performs processing for
adjustment of a transmission parameter of the wireless
terminal in the case where a value in the retransmission
number counter is equal to or greater than a predetermined
maximum number.
11. A message exchange method for communication
between a wireless base station and a wireless terminal,
comprising:
transmitting a message parameter from said wireless
parameter includes a message size indicating a data length
of a message to be transmitted from the wireless terminal
to the wireless base station;
transmitting from said wireless terminal to said
wireless base station a wireless-bandwidth request signal
requesting allocation of a wireless bandwidth for
transmission of said message to be transmitted, when a
time to transmit the message to be transmitted comes and
preparations for transmission of the message to be
transmitted are completed;
allocating to said wireless terminal by said
wireless base station a wireless bandwidth corresponding
to said message size of said message to be transmitted
when the wireless base station receives said wireless-
bandwidth request signal;
transmitting allocation information indicating the
allocated wireless bandwidth from said wireless base
station to said wireless terminal; and
transmitting said message to be transmitted, from
said wireless terminal to said wireless base station by
using the wireless bandwidth indicated by said allocation
information.
12. A message exchange method for communication
between a wireless base station and a wireless terminal,
comprising:
transmitting a first message parameter and a second
transmitting a first message parameter and a second
message parameter from said wireless terminal to said
wireless base station, where the first message parameter
includes identification information identifying a trigger
message and a message size indicating a data length of a
first message to be transmitted from the wireless terminal
to the wireless base station, the trigger message is a
message to trigger transmission of the first message to be
transmitted, and the second message parameter includes a
message size indicating a data length of a second message
to be transmitted from the wireless terminal to the
wireless base station;
transmitting from said wireless terminal to said
wireless base station a wireless-bandwidth request signal
requesting allocation of a wireless bandwidth for
transmission of said second message to be transmitted,
when a time to transmit the second message to be
transmitted comes and preparations for transmission of the
second message to be transmitted are completed;
allocating a first wireless bandwidth corresponding
to the message size of the first message to be transmitted,
to said wireless terminal by said wireless base station
when the wireless base station transmits said trigger
message to the wireless terminal, and allocating to the
wireless terminal by the wireless base station a second
wireless bandwidth corresponding to the message size of
said second message to be transmitted when the wireless
base station receives said wireless-bandwidth request
signal;
transmitting from said wireless base station to said
wireless terminal allocation information indicating the
allocated wireless bandwidth of said first wireless
bandwidth and said second wireless bandwidth; and
transmitting one of said first message to be
transmitted and said second message to be transmitted,
from said wireless terminal to said wireless base station
by using said allocated wireless bandwidth indicated by
said allocation information.
13. A wireless communication system in which
wireless message exchange is performed, comprising:
a wireless terminal including,
a message-parameter transmission means which
transmits a message parameter to a wireless base station,
where the message parameter includes identification
information identifying a trigger message and a message
size indicating a data length of a message to be
transmitted to the wireless base station, and the trigger
message is a message to trigger transmission of the
message to be transmitted, and
a message transmission means which transmits
the message to be transmitted to the wireless base station
by using a wireless bandwidth which is allocated by the
wireless base station and indicated by allocation
information after the wireless terminal receives the
trigger message and the allocation information from the
wireless base station; and
said wireless base station including,
a trigger-message transmission means which
transmits said trigger message to said wireless terminal,
a bandwidth allocation means which allocates to
the wireless terminal a wireless bandwidth corresponding
to said message size of said message to be transmitted,
after the trigger-message transmission means transmits the
trigger message, when the wireless base station receives
said message parameter from the wireless terminal, and
an allocation-information transmission means
which transmits to the wireless terminal said allocation
information indicating the first wireless bandwidth
allocated by the bandwidth allocation means.
14. The wireless communication system according to
claim 13, wherein:
said message-parameter transmission means in said
wireless terminal inserts in said message parameter a time
of delay occurring after reception of said trigger message
until completion of preparations for transmission of said
message to be transmitted, when the message-parameter
transmission means transmits the message parameter to said
wireless base station; and
said bandwidth allocation means in said wireless
base station allocates said first wireless bandwidth to
the wireless terminal after said time of delay elapses
since transmission of said trigger message.
15. The wireless communication system according to
claim 14, wherein: said message-parameter transmission
means in said wireless terminal transmits said message
parameter to said wireless base station only in the case
where said message size, said time of delay, or a
combination thereof of said message to be transmitted is
not identical to respective default values of the message
size and the time of delay which are respectively
predetermined.
16. The wireless communication system according to
claim 15, wherein said wireless base station further
includes a default-value transmission means which
transmits to said wireless terminal said default values of
the message size and the time of delay of said message to
be transmitted.
17. The wireless communication system according to
claim 16, wherein said wireless base station transmits by
broadcasting to said wireless terminal said default values
of the message size and the time of delay.
18. The wireless communication system according to
claim 13, wherein:
said trigger-message transmission means in said
wireless base station retransmits said trigger message in
the case where said message to be transmitted is not
transmitted from said wireless terminal through said first
wireless bandwidth after said allocation information is
transmitted to the wireless terminal;
said bandwidth allocation means in the wireless base
station reallocates a second wireless bandwidth to the
wireless terminal when the trigger-message transmission
means retransmits the trigger message; and
said allocation-information transmission means
transmits to the wireless terminal allocation information
indicating the second wireless bandwidth reallocated by
the bandwidth allocation means.
19. The wireless communication system according to
claim 18, wherein:
said message-parameter transmission means in said
wireless terminal inserts in said message parameter a time
of delay occurring after reception of said trigger message
until completion of preparations for transmission of said
message to be transmitted; and
said bandwidth allocation means in said wireless
base station allocates said first wireless bandwidth to
the wireless terminal after said time of delay elapses
since the trigger message is transmitted, and reallocates
said first wireless bandwidth to the wireless terminal
after said time of delay elapses since the trigger message
is retransmitted.
20. The wireless communication system according to
claim 13, wherein:
said bandwidth allocation means in said wireless
base station reallocates a wireless bandwidth to said
wireless terminal in the case where an error is detected
in said message to be transmitted after the message to be
transmitted is transmitted from the wireless terminal; and
said allocation-information transmission means
transmits to the wireless terminal allocation information
indicating the wireless bandwidth reallocated by the
bandwidth allocation means.
21. The wireless communication system according to
claim 13, wherein said wireless base station further
includes a transmission-parameter adjustment means which
performs processing for adjustment of a transmission
parameter of said wireless terminal in the case wher'e said
message to be transmitted is not transmitted from the
wireless terminal through said first wireless bandwidth
after said allocation information is transmitted to the
wireless terminal, or in the case where
an error is detected in the message to be transmitted
after the message to be transmitted is transmitted.
22. The wireless communication system according to
claim 13, wherein:
said trigger-message transmission means in said
wireless base station retransmits said trigger message in
the case where said message to be transmitted is not
transmitted from the wireless terminal through the
allocated wireless bandwidth after said allocation
information is transmitted to the wireless terminal;
said bandwidth allocation means in the wireless base
station reallocates a wireless bandwidth to the wireless
terminal in the case where the trigger message is
retransmitted, or in the case where an error is detected
in the message to be transmitted after the message to be
transmitted is transmitted;
said allocation-information transmission means in
the wireless base station transmits to the wireless
terminal allocation information indicating the wireless
bandwidth reallocated by the bandwidth allocation means;
and
a transmission-parameter adjustment means in the
wireless base station sets the number of retransmissions
of allocation information in a retransmission number
counter, and performs processing for adjustment of a
transmission parameter of the wireless terminal in the
case where a value in the retransmission number counter
becomes equal to or greater than a predetermined maximum
number.
23. A wireless communication system in which
wireless message exchange is performed, comprising:
a wireless terminal including,
a message-parameter transmission means which
transmits a message parameter to a wireless base station,
where the message parameter includes a message size
indicating a data length of a message to be transmitted to
the wireless base station,
a bandwidth-request transmission means which
transmits to the wireless base station a wireless-
bandwidth request signal requesting allocation of a
wireless bandwidth for transmission of the message to be
transmitted, when a time to transmit the message to be
transmitted comes and preparations for transmission of the
message to be transmitted are completed, and
a message transmission means which transmits
the message to be transmitted to the wireless base station
by using a wireless bandwidth which is allocated by the
wireless base station and indicated by allocation
information, when the wireless terminal receives the
allocation information from the wireless base station; and
said wireless base station including,
a bandwidth allocation means which allocates to
the wireless terminal a wireless bandwidth corresponding
to said message size of said message to be transmitted,
when the wireless base station receives said wireless-
bandwidth request signal, and
an allocation-information transmission means
which transmits to the wireless terminal allocation
information indicating the wireless bandwidth allocated by
the bandwidth allocation means.
24. A wireless communication system in which
wireless message exchange is performed, comprising:
a wireless terminal including,
a message-parameter transmission means which
transmits a first message parameter and a second message
parameter to a wireless base station, where the first
message parameter includes identification information
identifying a trigger message and a message size
indicating a data length of a first message to be
transmitted from the wireless terminal to the wireless
base station, the trigger message is a message to trigger
transmission of the first message to be transmitted, and
the second message parameter includes a message size
indicating a data length of a second message to be
transmitted from the wireless terminal to the wireless
base station;
a bandwidth-request transmission means which
transmits to the wireless base station a wireless-
bandwidth request signal requesting allocation of a
wireless bandwidth for transmission of the second message
to be transmitted, when a time to transmit the second
message to be transmitted comes and preparations for
transmission of the second message to be transmitted are
completed, and
a message transmission means which transmits
one of the first message to be transmitted and the second
message to be transmitted, to the wireless base station by
using a wireless bandwidth which is allocated by the
wireless base station and indicated by allocation
information, when the wireless terminal receives the
allocation information; and
said wireless base station including,
a trigger-message transmission means which
transmits said trigger message to said wireless terminal,
a bandwidth allocation means which allocates to
the wireless terminal a first wireless bandwidth
corresponding to said message size of said first message
to be transmitted, after the trigger-message transmission
means transmits the trigger message, and allocates to the
wireless terminal a second wireless bandwidth
corresponding to said message size of said second message
to be transmitted, when the wireless base station receives
said wireless-bandwidth request signal from said wireless
terminal, and
an allocation-information transmission means
which transmits to the wireless terminal allocation
information indicating one of the first wireless bandwidth
and the second wireless bandwidth which is allocated by
the bandwidth allocation means.
25. A wireless terminal which wirelessly exchanges
messages with a wireless base station, comprising:
a message-parameter transmission means which
transmits a message parameter to said wireless base
station, where the message parameter includes
identification information identifying a trigger message
and a message size indicating a data length of a message
to be transmitted to the wireless base station, and the
trigger message is a message to trigger transmission of
the message to be transmitted; and
a message transmission means which transmits the
message to be transmitted to the wireless base station by
using a wireless bandwidth which is allocated by the
wireless base station and indicated by allocation
information after the wireless terminal receives the
trigger message and the allocation information from the
wireless base station.
26. A wireless base station which wirelessly
exchanges messages with a wireless terminal, comprising:
a trigger-message transmission means which transmits
a trigger message to said wireless terminal, where the
message to be transmitted, stores the received message
parameter in advance, and allocates to the wireless
terminal a wireless bandwidth corresponding to the message
size of the message to be transmitted, after said trigger-
message transmission means transmits the trigger message;
and
an allocation-information transmission means which
transmits to said wireless terminal allocation information
indicating the wireless bandwidth allocated by the
bandwidth allocation means.
27. A wireless terminal which wirelessly exchanges
messages with a wireless base station, comprising:
a message-parameter transmission means which
transmits a message parameter to said wireless base
station, where the message parameter includes a message
size indicating a data length of a message to be
transmitted to the wireless base station;
a bandwidth-request transmission means which
transmits to said wireless base station a wireless-
bandwidth request signal requesting allocation of a
wireless bandwidth for transmission of the message to be
transmitted, when a time to transmit the message to be
transmitted comes and preparations for transmission of the
message to be transmitted are completed; and
a message transmission means which transmits said
message to be transmitted to said wireless base station by
using a wireless bandwidth which is allocated by the
wireless base station and indicated by allocation
information, when the wireless terminal receives the
allocation information.
28. A wireless base station which wirelessly
exchanges messages with a wireless terminal, comprising:
a bandwidth allocation means which receives from
said wireless terminal a message parameter including a
message size indicating a data length of a message to be
transmitted from the wireless terminal to the wireless
base station, stores the received message parameter in
advance, and allocates to the wireless terminal a wireless
bandwidth corresponding to the message size of the message
to be transmitted, when the wireless base station receives
from the wireless terminal a wireless-bandwidth request
signal requesting allocation of a wireless bandwidth for
transmission of the message to be transmitted; and
an allocation-information transmission means which
transmits to said wireless terminal allocation information
indicating the wireless bandwidth allocated by the
bandwidth allocation means.

The present invention enables efficient message
communication by a wireless terminal.
A wireless terminal (1) transmits to a wireless base
station (2) a message parameter (3) which includes
identification information identifying a trigger message
(4) and a message size indicating the data length of a
message (6), which is to be transmitted from the wireless
terminal (1) to the wireless base station (2). The trigger
message (4) is a message to trigger transmission of the
message (6) to be transmitted. Next, the wireless base
station (2) transmits the trigger message (4) to the
wireless terminal (1), and thereafter allocates to the
wireless terminal (1) a wireless bandwidth corresponding
to the message size of the message (6) to be transmitted.
Further, the wireless base station (2) transmits to the
wireless terminal (1) allocation information (5)
indicating the allocated wireless bandwidth. Then, the
wireless terminal (1) transmits the message (6) to be
transmitted, to the wireless base station (2) by using the
wireless bandwidth indicated by the allocation information
(5).