D e s c r i p t i o n
Field of the invention
The invention relates to the field of wireless telecommunication, more specifically to
transmitting radio configuration parameters from a base station to a relay node.
Background and related art
The relay node functions as a relay between a user equipment and a base station.
The user equipment may be for example a mobile phone, a PDA, or a laptop. The
relay node extends the coverage area of the base station. By placing a relay node at
a suitable position the coverage area of the base station and/or an overall data rate
within a cell of the base station may be significantly increased. A user equipment
may for example communicate directly with the base station or via a relay node. In
case of communication with a relay node data transmitted from the user equipment
to the relay node is forwarded to the base station. Data which is indicated to be sent
to the user equipment is transmitted from the base station to the relay node. The
relay node forwards the data to the user equipment.
Summary
It is an object of the present invention to provide an improved method of transmitting
radio configuration parameters from a base station to a relay node, an improved
base station, an improved relay node, and improved computer readable storage
media for a relay node and a base station apparatus.
These objects are achieved by the method, the base station apparatus, the relay
node and the computer readable storage media according to the independent
claims. Embodiments of the invention are given in the dependent claims.
The invention relates to a method of transmitting radio configuration parameters
from a base station to a relay node in a wireless telecommunication system. The
method comprises the step of transmitting a signal from the base station to the relay
node over an air interface via a protocol. The protocol is adapted to communication
between two network nodes. The signal is indicative of the radio configuration pa¬
rameters and/or at least one unique cell global identity.
The at least one unique cell global identity is unique in the wireless telecommunica¬
tion network. The at least one cell global identity is used for determining an identifier
of the base station. And the identifier of the base station is used for routing signals
in the wireless telecommunication network. Preferably, the cell global identity con¬
sists of a public land mobile network (PLNM) identifier plus 28 bits. The PLMN iden¬
tifier plus the leftmost 20 bits of the 28 bits are equal to the relay node identifier. The
PLMN identifier is an identifier for the wireless telecommunication network. Each
network provider has a corresponding PLMN identifier.
One cell global identity is assigned to one relay node cell. In other words, more than
one cell global identity is transmitted to the relay node, if the relay node serves more
than one relay node cell.
The protocol used for transmitting the signal is intentionally adapted to a communi
cation between two network nodes. For example the protocol may be an S 1 protocol
between an MME (MME = Mobility Management Entity) and an eNB (eNB = en¬
hanced NodeB) in 3GPP LTE (3GPP = 3rd Generation Partnership Project; LTE =
Long Term Evolution) or an X2 protocol between two eNBs in 3GPP LTE. The pro
tocol is known to the relay node and the base station. Therefore, configuration mes¬
sages defined in the S 1 or X2 protocol are terminated in both the relay node and the
base station and may thus be used for transmitting the radio configuration parame¬
ters from the base station to the relay node. In other words, the message overhead
is reduced and there is no need to define or use a redundant radio message for this.
The configuration messages may be a setup configuration messages or an update
configuration messages. A setup configuration message is transmitted during a
start-up phase of the relay node. An update configuration is transmitted for updating
the radio configuration parameters of the relay node.
The configuration may be used by the relay node for communicating with user
equipments. The configuration may for example define the type of the relay node.
The relay node may be for example an in-band or an out-of-band relay node. An inband
relay node transmits signals with the same frequency as the base station,
while an out of band relay node transmits signals with a different frequency than the
base station. Additionally, the configuration may comprise the frequency used by the
relay node, the subframe configuration, and/or start symbols such as start symbols
of a Reverse Physical Downlink Control Channel (R-PDCCH).
The signal being indicative of the radio configuration parameters and of the cell
global identity is advantageous, because the signal overhead is reduced. The cell
global identity and the radio configuration parameters are required by the relay node
for communication in the wireless telecommunication network. Additional messages
are avoided by transmitting both of them via the signal over the protocol being in¬
tended to be used for communication between two network nodes. The signal may
for example be comprised by a configuration setup message or by a configuration
update message. Thus, only one message is needed for transmitting the radio con¬
figuration parameters and the cell global identity. Additionally, the configuration
setup message and/or the configuration update message may comprise further pa¬
rameters like network configuration parameters. Thus, radio configuration parame
ters, network configuration parameters and the cell global identity are transmitted by
transmitting the configuration setup message and/or the configuration update mes¬
sage.
According to embodiments of the invention the wireless telecommunication network
is a digital cellular telecommunication network.
According to embodiments of the invention the relay node is adapted to forwarding
data received from the base station to a user equipment. The relay node is adapted
to use the radio configuration parameters for forwarding the data to the user equipment.
According to embodiments of the invention the method further comprises the step of
using the radio configuration parameters for wireless communication between the
relay node and at least one user equipment.
According to embodiments of the invention a configuration setup or configuration
update message comprises the signal. The configuration setup or configuration up¬
date message also comprises network configuration parameters. The configuration
setup or configuration update message may be for example transmitted when a re¬
lay node is switched on. In this case network configuration parameters are transmit¬
ted from the base station to the relay node. The network configuration parameters
4
may be for example a list of tracking areas, or a list of PLMNs, or a list of cells. The
radio configuration parameters and/or the at least one global cell identity may be
comprised by the configuration setup or configuration update message. A container
in the network configuration message for example may also comprise the radio configuration
parameters and/or the at least one global cell identity. The container may
be for example labeled as containing radio configuration parameters and/or the at
least one unique cell global identity and information within the container may be ex¬
tracted by the relay node. Thus, the network configuration parameters and the radio
configuration parameters and/or the at least one unique cell global identity are
transmitted from the base station to the relay node by transmitting a network con¬
figuration setup or configuration update message. Preferably, the configuration
setup or configuration update message may be transmitted from the base station to
the relay node during a start-up phase of the relay node.
According to embodiments of the invention the signal is transmitted from the base
station to the relay node using a configuration update procedure. During the configu
ration update procedure the signal may be for example transmitted using the S 1 or
X2 protocol. The update procedure according to the S 1 or X2 protocol may be for
example a so-called eNB configuration update, or a MME configuration update pro¬
cedure. In this case a container of the configuration update message may also
comprise the radio configuration parameters and/or the unique cell global identity.
Embodiments of the invention are advantageous because the configuration update
procedure may be used for the configuration update and for updating the radio con¬
figuration parameters and/or the unique cell global identity. Thus, the message
overhead is reduced and applying a redundant dedicated message is avoided.
According to embodiments of the invention the radio configuration parameters com
prise a relay node type, a frequency, sub-frames configuration, and/or start symbols.
According to embodiments of the invention a container of the configuration setup or
configuration update message comprises the radio configuration parameters and/or
the signal.
According to embodiments of the invention the method further comprises a step of
assigning a relay node identifier to the relay node. The relay node identifier is identi¬
cal to a base station identifier of the base station. This is advantageous for handover
procedures and routing signals.
At least one unique cell global identity is determined for at least one relay node cell
by the base station. One relay node may for example serve several relay node cells.
Each relay node cell corresponds to a unique cell global identity. Thus, in case of
several relay node cells being served by different relay nodes it is possible that two
relay node cells could have the same cell global identity. This is avoided by the base
station assigning the relay node identifier. In other words, the base station deter¬
mines at least one unique cell global identity for at least one relay node cell and
avoids determining one cell global identity for more than one relay node cell.
The at least one unique cell global identity is assigned to the at least one relay node
cell by the base station.
According to embodiments of the invention the at least one unique cell global iden¬
tity is transmitted together with the signal using the S 1 or X2 protocol. Alternatively,
the unique cell global identity is comprised by the signal. In general, the at least one
unique cell global identity is transmitted together with the radio configuration parameters
from the base station to the relay node. A container of a network configu¬
ration message, a configuration setup message or a configuration update message
may comprise the at least one unique cell global identity.
In another aspect the invention relates to a base station apparatus. The base station
apparatus comprises means for transmitting a signal from the base station to a relay
node over an air interface via a protocol. The protocol is adapted to communication
between two network nodes. The signal is indicative of radio configuration parame¬
ters and/or at least one unique cell global identity.
In another aspect the invention relates to a relay node. The relay node comprises
means for receiving a signal from a base station over an air interface via a protocol.
The protocol is adapted to communication between two network nodes. The signal
is indicative of radio configuration parameters and/or at least one unique cell global
identity. The relay node further comprises means for using the radio configuration
parameters for wireless telecommunication with at least one user equipment.
In yet another aspect the invention relates to a computer readable storage medium.
The computer readable storage medium comprises instructions that when executed
by a base station cause the base station to perform a method of transmitting radio
configuration parameters from the base station to a relay node. The instructions
may be for example program instructions executed by a processor of the base sta
tion. The method comprises transmitting a signal from the base station to the relay
node over an air interface via a protocol. The protocol is adapted to communication
between two network nodes. The signal is indicative of the radio configuration pa¬
rameters and/or at least one unique cell global identity.
In yet another aspect the invention relates to a computer readable storage medium.
The computer readable storage medium comprises instructions that when executed
by a relay node cause the relay node to perform a method of receiving and taking
into use radio configuration parameters and/or at least one unique cell global iden¬
tity from a base station. The instructions may be for example program instructions
executed a processor of the relay node.
The method comprises receiving a signal from the base station over an air interface
via a protocol. The protocol is adapted to communication between two network
nodes. The signal is indicative of the radio configuration parameters and/or at least
one unique cell global identity. The radio configuration parameters are used by the
relay node for a wireless communication with at least one user equipment.
Brief description of the drawings
In the following preferred embodiments of the invention will be described, by way of
example only, and with reference to the drawings in which:
Figure 1 is a schematic view of a base station transmitting a signal to a relay
node, the signal being indicative of radio configuration parameters,
and
Figure 2 is a block diagram of a relay node and a base station.
Detailed description
Like numbered elements in these figures are either identical elements or perform
the same function. Elements which have been discussed previously will not neces¬
sarily be discussed in later figures if the function is identical.
Figure 1 is a schematic view of a relay node 100 and a base station 102 exchanging
signals 104 and 106. Relay node 100 transmits signal 104 to base station 102. The
signal 104 is indicative of requesting a configuration setup or configuration update
signal from the base station 102. The signal 104 may be for example transmitted
from the relay node to the base station 102 during a start up procedure of relay
node 100 after relay node 100 has been switched on. The signal 104 requesting a
response from base station 102 may also be transmitted during a configuration up¬
date procedure. Signals 104 and 106 are exchanged according to a protocol, which
is adapted to be used for communication between two network nodes. A network
node may be for example a base station such as base station 02 and/or a central
network entity such as a mobility management entity (MME). After having received
signal 104 the base station 102 transmits signal 106 to relay node 100. Signal 106 is
indicative of radio configuration parameters. The radio configuration parameters are
adapted to be used by the relay node 100 for communication with a user equipment
(not depicted). Radio configuration parameters may be for example the type of the
relay node, the frequency to be used by the relay node for communication with a
user equipment, sub frames configuration, and/or start symbols to be used by the
relay node for telecommunication with at least one user equipment. The signal 106
may be comprised by a configuration setup or configuration update message. The
configuration setup or configuration update message may also comprise network
configuration parameters. By transmitting the network configuration parameters and
the radio configuration parameters within one single setup or configuration message
the message overhead is reduced and signaling traffic is reduced. The radio con¬
figuration parameters may also for example be comprised by a container in the configuration
setup or configuration update message.
Additionally or alternatively the signal 106 also comprises at least one cell global
identity for at least one relay node cell. The relay node 100 may for example serve a
plurality of relay node cells. For each relay node cell a unique cell global identity is
required. The cell global identity for each relay node cell is determined by base station
102 and transmitted to relay node 100. Transmitting the at least one relay node
cell global identity may be performed for example by adding the cell global identity
to signal 106 or by transmitting the cell global identity together with signal 106 to
relay node 00. In other words, the cell global identity may also be comprised by a
network configuration or configuration update message or by a configuration setup
message. Preferably, the cell global identity is also transmitted via the X2 or S 1 pro¬
tocol.
This is advantageous for avoiding unnecessary message overhead or redundant
messages and reducing the traffic and signaling transmitted from base station 102
to relay node 100. The messages used for transmitting signal 106 and/or the at least
one cell global identity are also used for transmitting network configuration parame¬
ters. Thus, no new messages being exchanged between relay node 100 and base
station 102 need to be defined for allowing transmission of signal 106 and/or the at
least once cell global identity from base station 102 to relay node 100.
Figure two is a block diagram of a relay node 100 and a base station 102. The relay
node 00 comprises means 200 for communication with a user equipment 202 and
base station 102. The means 200 may be for example an antenna. User equipment
202 may be for example a mobile phone. Base station 102 comprises means 204
for communicating with relay node 100. Means 204 may be for example an antenna.
Thus, relay node 100 and base station 02 are adapted for communicating with
each other via an air interface. According to embodiments of the invention commu¬
nication between relay node 100 and base station 102 is performed according to a
protocol, which is adapted to be used for communication between two network
nodes such as a base station and/or a mobility management entity (MME). The protocol
may be for example an S 1 or a X2 protocol. Further, relay node 100 comprises
a data storage 206. In the data storage 206 a program 208 is stored. The program
208 comprises instructions. Relay node 100 further comprises a processor 210.
Processor 210 is adapted for executing program instructions 208. For example,
when relay node 100 is switched on, processor 2 10 executes program instructions
208. Program instructions 208 cause the relay node 100 to request radio configura¬
tion parameters from base station 102. Additionally or alternatively cell global identi¬
ties may be requested by relay node 100 from base station 102. Base station 102
comprises a data storage 212 and a processor 214. In data storage 2 2 program
instructions 216 are stored. When receiving a request from relay node 100 for
transmitting radio configuration parameters and/or at least one cell global identity,
the program instructions 216 executed by processor 214 cause the base station 102
to transmit a signal to relay node 100, the signal being indicative of the radio con¬
figuration parameters and/or the at least one cell global identity. The signal may be
transmitted together with network configuration parameters or the signal may be
comprised by a configuration setup or configuration update message. The signal
may be for example comprised by a container in the network configuration mes
sage. When the signal is received by relay node 100 the program instructions 208
cause the relay node 100 to use the received radio configuration parameters and/or
the at least one cell global identity for communication with mobile device 202.
L i s t o f r e f e r e n c e n u m e r a l s
100 relay node
102 base station
104 signal
106 signal
200 antenna
202 user equipment
204 antenna
206 data storage
208 program instructions
210 processor
212 data storage
214 processor
216 program instructions
C a i m s
. A method of transmitting radio configuration parameters from a base station
(102) to a relay node (100) in a wireless telecommunication system, the
method comprising the step of:
- transmitting a signal (106) from the base station to the relay node over
an air interface via a protocol, the protocol being adapted to communi
cation between two network nodes, wherein the signal is indicative of
the radio configuration parameters and/or at least one unique cell glo¬
bal identity.
2 . Method according to claim 1, wherein the method further comprises the relay
node applying the radio configuration parameters for forwarding data re¬
ceived from the base station to a user equipment.
3. Method according to any one of the preceding claims, wherein the method
further comprises the step of
- using the radio configuration parameters for wireless telecommunica
tion between the relay node and at least one user equipment.
4 . Method according to any one of the preceding claims, wherein a configura¬
tion setup or configuration update message comprises the signal, and
wherein the configuration setup or configuration update message also com¬
prises network configuration parameters.
5. Method according to any one of the preceding claims, wherein the signal is
transmitted during a start-up phase of the relay node.
6 . Method according to any one of the preceding claims, wherein the protocol is
a S 1 or an X2 protocol.
7 . Method according to claim 6 , wherein the signal is transmitted from the base
station to the relay node using a configuration update procedure.
8. Method according to any one of the preceding claims, wherein the radio con
figuration parameters comprise a relay node type, a frequency, subframe
configurations, and/or start symbols.
9 . Method according to any one of the claims 4-8, wherein the signal is com¬
prised by a container in the configuration setup or configuration update mes¬
sage.
10. Method according to any one of the preceding claims, wherein the method
further comprises the steps of:
- assigning a relay node identifier to the relay node, the relay node iden¬
tifier being identical to a base station identifier of the base station;
- determining the at least unique cell global identity for at least one relay
node cell by the base station; and
- assigning the at least one unique cell global identity to the at least one
relay node cell by the base station.
11.Method according to claim 10, wherein the at least one unique cell global
identity is transmitted together with the signal using the S 1 or X2 protocol or
comprised by the signal.
12. A base station apparatus ( 1 02), wherein the base station apparatus compri¬
ses:
- means (204; 21 ) for transmitting a signal from the base station to a
relay node over an air interface via a protocol, the protocol being
adapted to communication between two network nodes, wherein the
signal is indicative of radio configuration parameters and/or a unique
cell global identity.
13.A relay node (100), wherein the relay node comprises:
- means (200; 210) for receiving a signal from a base station over an air
interface via a protocol, the protocol being adapted to communication
between two network nodes, wherein the signal is indicative of radio
configuration parameters and/or a unique cell global identity; and
- means (210) for using the radio configuration parameters and/or the
unique cell global identity for wireless telecommunication with at least
one user equipment.
14.A computer-readable storage medium (212), the computer-readable storage
medium comprising instructions (216) that when executed by a base station
(102) cause the base station to perform a method of transmitting radio con¬
figuration parameters from the base station to a relay node, the method comprising
- transmitting a signal (106) from the base station to the relay node over
an air interface via a protocol, the protocol being adapted to communi¬
cation between two network nodes, wherein the signal is indicative of
the radio configuration parameters and/or a unique cell global identity.
5 .A computer-readable storage medium (206), the computer-readable storage
medium comprising instructions (208) that when executed by a relay node
( 100) cause the relay node to perform a method of receiving radio conf igura
tion parameters from a base station, the method comprising:
- receiving a signal ( 06) from the base station over an air interface via
a protocol, the protocol being adapted to communication between two
network nodes, wherein the signal is indicative of the radio configura¬
tion parameters and/or a unique cell global identity; and
- using the radio configuration parameters and/or the unique cell global
identity for wireless telecommunication with at least one user equipment.