COMMUNICATIONS DEVICE, APPARATUS,
SYSTEM, METHOD AND COMPUTER IMPLEMENTABLE IN¬
STRUCTIONS PRODUCT
Technical Field
[0001] The present invention relates to a communications system. The invention has
particular but not exclusive relevance to wireless communications systems and devices
thereof operating according to the 3rd Generation Partnership Project (3GPP) standards
or equivalents or derivatives thereof. The invention has particular although not
exclusive relevance to the provision of assistance information by Machine-Type Com
munications devices.
Background Art
[0002] The latest developments of the 3GPP standards are referred to as the Long Term
Evolution (LTE) of EPC (Evolved Packet Core) network and E-UTRAN (Evolved
UMTS Terrestrial Radio Access Network). Under the 3GPP standards, a NodeB (or an
eNB in LTE) is the base station via which communications devices connect to a core
network and communicate to other communications devices or remote servers. For
simplicity, the present application will use the term base station to refer to any such
base stations. In the core network, a home subscriber server (HSS) entity holds in
formation related to the services subscribed/available for each communication device.
Mobility of the communication devices (i.e. access to the core network via various
radio access networks) is managed by a so-called mobility management entity (MME).
The MME communicates with the communication devices using non-access stratum
(NAS) protocol messages.
[0003] Communications devices might be, for example, mobile communications devices
such as mobile telephones, smartphones, user equipment, personal digital assistants,
laptop/tablet computers, web browsers, e-book readers and the like. Such mobile (or
even generally stationary) devices are typically operated by a user. However, 3GPP
standards also make it possible to connect Machine-Type Communications (MTC)
devices (sometimes also referred to as Machine-to-Machine (M2M) communications
devices) to the network, which typically comprise automated equipment, such as
various measuring equipment, telemetry equipment, monitoring systems, tracking and
tracing devices, in-vehicle safety systems, vehicle maintenance systems, road sensors,
digital billboards, point of sale (POS) terminals, remote control systems and the like.
MTC devices can be implemented as a part of a (generally) stationary apparatus such
as vending machines, roadside sensors, POS terminals, although some MTC devices
can be embedded in non-stationary apparatus (e.g. vehicles) or attached to animals or
persons to be monitored/tracked.
[0004] For simplicity, the present application refers to MTC devices in the description but it
will be appreciated that the technology described can be implemented on any commu
nications devices (mobile and/or generally stationary) that can connect to a commu
nications network for sending/receiving data, regardless whether such communications
devices are controlled by human input or software instructions stored in memory. In
particular, the term 'MTC device' is intended to cover any communications device im
plementing MTC functionality, such as mobile telephones / user equipment (UE)
running an MTC application.
[0005] In order to be able to communicate with each other, a Radio Resource Control (RRC)
connection needs to be established between an MTC device and the radio access
network (RAN), i.e. a base station of that RAN currently serving the MTC device.
Under normal circumstances, an RRC connection for a particular MTC device is
usually released by the RAN/base station due to inactivity of the MTC device. In some
cases, an existing RRC connection may also be released due to a communication
failure, authentication error, and/or the like. An RRC connection may also be released
upon a request from a core network entity (e.g. the MME) and/or the MTC device
itself (e.g. when it is being switched off).
[0006] Inactivity of a communications device is determined by the serving base station at the
expiry of a so called 'user inactivity' timer, when the base station releases the RRC
connection for the inactive communications device. Upon expiry of the user inactivity
timer, the base station also notifies the core network about the release of the RRC
connection using a so-called UE context release procedure, which is described in more
detail in section 5.3.5 of the 3GPP TS23.401 standards specification.
[0007] Since the use and the length of the user inactivity timer are implementation
dependant, details of these are not provided in the above specification. However, the
release of a RRC connection for inactivity of an MTC device is typically carried out as
follows. The base station runs a user inactivity timer (per RRC connection) during the
existence of an RRC connection between the base station and the MTC device.
Whenever the MTC device sends or receives data, the base station re-starts the user in
activity timer associated with that MTC device (i.e. the RRC connection used by the
MTC device). When the user inactivity timer expires (i.e. it reaches a predefined value
or it reaches zero if counting down from the predefined value), the base station initiates
the RRC connection release procedure referred to above.
[0008] MTC devices connect to the network whenever they have data to send to or receive
from a remote 'machine' (e.g. a server) or user. MTC devices use communication
protocols and standards that are optimised for mobile telephones or similar items of
user equipment (UEs). However, MTC devices, once deployed, typically operate
without requiring human supervision or interaction, and follow software instructions
stored in an internal memory. MTC devices might also remain stationary and/or
inactive for a long period of time. The specific network requirements to support MTC
devices have been dealt with in the 3GPP TS 22.368 standard, the contents of which
are incorporated herein by reference.
[0009] In accordance with section 7.2.5 of TS 22.368, MTC devices can benefit from a socalled
'small data transmissions' functionality, intended for the sending and/or
receiving of small amounts of data (typically in the order of IK (1024) octets of data).
In order to implement this feature, the system supports transmissions of small amounts
of data with minimal impact on e.g. signalling overhead, network resources, and delay
for reallocation of resources, regardless whether or not the MTC device is attached to
the network before transmitting data. The network counts the number of small data
transmissions per subscription e.g. for charging or statistical purposes. This allows
charging and accounting of small data transmissions between network operators on a
bulk basis.
[0010] More recently, optimisation of small data transmissions (including keep-alive
messages from smartphones) has been considered by 3GPP as part of the MTCe-
SDDTE (Small Data transmission and Device Triggering Enhancements) work item,
published under section 5.1 of 3GPP TR23.887 - the contents of which are in
corporated herein by reference.
Summary of Invention
Technical Problem
[001 1] One of the key issues is the efficiency of small data transmissions (including keepalive
messages) by MTC devices. It has been suggested that in case of mobile
originated small data transmissions, instead of using a base station initiated RRC
connection release procedure (e.g. inactivity timer run by the base station), the MME
may control the RRC connection release.
[0012] According to section 5.1.1.3.1.1 of TR23.887, "The MME uses knowledge of the
subscriber to determine whether to proceed with the full UE triggered Service Request
procedure, or, to immediately release the RRC connection, or to wait for some time
(e.g. to see if a downlink IP packet causes the S-GW to send a Downlink Data noti
fication to the MME)". This MME centric approach may be applied in case of mobile
originated (MO) small data transmissions. The term 'Service Request' procedure as
used herein includes, for example, the exchange of keep-alive messages and/or small
data transmissions by the MTC device.
[0013] However, "knowledge of the subscriber" that is already available from the subscriber
information stored in the MME and/or HSS may not always be sufficient for the MME
to decide whether or not the RRC connection for a particular MTC device can be
released. For example, this suggested approach may lead to an early release of the
RRC connection by the MME (i.e. whilst the MTC device still has data to send/
receive), which would in turn generate additional signalling messages between the
MTC device and the base station in order to re-establish the interrupted RRC
connection between them. In some cases, the MME may decide, based on the in
formation available to it, not to release a particular RRC connection even if the MTC
device does not require this RRC connection anymore (e.g. it has no more data to rend/
receive). In this case, the RRC connection may be maintained until expiry of the user
inactivity timer at the base station (or even longer if the base station relies on the MME
to release the RRC connection). This is also wasteful of the network resources.
[0014] It has also been suggested in TR23.887 that in case of mobile terminated (MT) small
data transmissions, the MTC device can request its serving base station to release the
RRC connection. In MT case, the MTC device typically sends an Internet Protocol (IP)
packet to the MME as an acknowledgement. The IP packet is sent in an encrypted in
formation element (IE) using NAS signalling included in an uplink information
transfer message transmitted to the base station. The base station forwards the NAS
signalling to the MME. Upon receipt of the IP packet, the MME decrypts the IE, and
also controls termination of the requesting MTC device's connection in the core
network, e.g. by terminating a corresponding bearer at a gateway serving entity serving
the MTC device (i.e. the so called serving gateway or S-GW). The request for the base
station to release the RRC connection may be added as an optional IE in the uplink in
formation transfer message sent from the MTC device to the base station.
[0015] However, the optional release indication from the MTC device to its serving base
station also does not cover all possible MT scenarios and it does not address the issues
associated with the MME centric control suggested for MO small data transmissions.
[0016] Accordingly, preferred embodiments of the present invention aim to provide methods
and apparatus which address or at least partially deal with one or more of the above
needs.
[0017] Although for efficiency of understanding for those of skill in the art, the invention
will be described in detail in the context of a 3GPP system (UMTS, LTE), the
principles of the invention can be applied to other systems in which communications
devices or User Equipment (UE) access a core network using a radio access
technology.
Solution to Problem
[0018] In one aspect, the invention provides a communications device for providing information
to a network entity for use in determining whether a radio bearer should be
maintained or released, the communications device comprising: means for establishing
the radio bearer via a base station of a communications system for sending or receiving
data; means for sending or receiving data using the established radio bearer; means for
providing to the network entity information configured to indicate a potential for future
data to be sent or received by said communications device for use, by the network
entity, in determining whether the radio bearer should be maintained or released ac
cordingly.
[0019] Said information configured to indicate a potential for future data to be sent or
received by said communications device may comprise information configured to
indicate whether or not any further data is to be sent or received by said commu
nications device.
[0020] Said information configured to indicate a potential for future data to be sent or
received by said communications device may comprise information configured to
indicate whether or not a user-plane connection is required for said communications
device to be able to send or receive said future data.
[0021] In one aspect, the invention provides a communications device for providing in
formation to a network entity for use in determining whether a radio bearer should be
maintained or released, the communications device comprising: means for establishing
the radio bearer via a base station of a communications system for sending or receiving
data; means for sending or receiving data using the established radio bearer; means for
determining at least one of: i) whether or not any further data is to be sent or received
by said communications device; and ii) whether or not a user-plane connection is
required for said communications device; and means for providing to the network
entity information identifying a result of said determination for use, by the network
entity, in determining whether the radio bearer should be maintained or released ac
cordingly.
[0022] The means for sending or receiving data may be operable to send or receive said data
as a data packet in a payload of a control plane message. In this case, the means for
sending or receiving data may be operable to send or receive said data as a data packet
in a payload of a radio resource control (RRC) message. For example, the means for
sending or receiving data may be operable to send said data as a data packet in a
payload of an uplink information transfer message or receive said data as a data packet
in a payload of a downlink information transfer message. The means for sending or
receiving data may also be operable to send or receive said data as a data packet in a
payload of an RRC connection setup complete message.
[0023] The information providing means may be operable to provide said information
identifying a result of said determination to said network entity as part of a procedure
for establishing said radio bearer.
[0024] The determining means may determine that no further data is to be sent or received
by said communications device, in which case said information identifying a result of
said determination may comprise an indication that no further data is to be sent or
received by said communications device.
[0025] The determining means may determine that further data is to be sent or received by
said communications device, in which case said information identifying a result of said
determination may comprise an indication that further data is to be sent or received by
said communications device. In this case, the further data may comprise data to be sent
in response to data received by said communications device. The further data may also
comprise data requiring establishment of a user plane connection for said commu
nications device.
[0026] The providing means may be operable to provide said information identifying a
result of said determination to said network entity by sending at least one RRC
message to said base station. In this case, the providing means may be operable to send
said at least one RRC message as part of an RRC connection establishment procedure.
The providing means may be operable to provide said information identifying a result
of said determination using at least one information element in said at least one RRC
message.
[0027] The at least one RRC message may include at least one non-access stratum (NAS)
message. In this case, the providing means may be operable to provide said in
formation identifying a result of said determination using said at least one NAS
message.
[0028] The means for sending or receiving data may be operable to send said data as a data
packet in a payload of said at least one RRC message in which said information
identifying a result of said determination is provided to said network entity. The data
packet may require a response to be received at said communications device, in which
case said information identifying a result of said determination may indicate that no
further data is to be sent or received by said communications device after receipt of
said response. The data packet may comprise data sent in response to data received by
said communications device, in which case wherein said information identifying a
result of said determination may indicate that said communications device expects no
further data to be sent or received after sending said data packet.
[0029] The providing means may be operable to send said information identifying a result of
said determination to said base station. The providing means may be operable to send
said information identifying a result of said determination to a core network entity. The
providing means may be operable to send said information identifying a result of said
determination to said base station via said core network entity.
[0030] The communications device may comprise at least one of a machine-type commu
nications device, a mobile telephone, and user equipment operating in accordance with
long term evolution (LTE) standards.
[0031] In one aspect, the invention also provides an apparatus for managing a radio bearer
for a communications device, the apparatus comprising: means for communicating
data with said communications device using a radio bearer; means for obtaining in
formation from said communications device, said information indicating, for the com
munications device, at least one of: i) whether or not any further data is to be sent or
received by said communications device; and ii) whether or not a user-plane
connection is required by said communications device; means for determining, from
said obtained information, whether the radio bearer should be maintained or released;
and means for maintaining said radio bearer in dependence of said determination.
[0032] The data communicating means may be operable to send or receive said data as a
data packet in a payload of a control plane message. In this case, the data commu
nicating means may be operable to send or receive said data as a data packet in a
payload of a radio resource control (RRC) message. For example, the data commu
nicating means may be operable to send said data as a data packet in a payload of a
downlink information transfer message or receive said data as a data packet in a
payload of an uplink information transfer message. The data communicating means
may also be operable to receive said data as a data packet in a payload of an RRC
connection setup complete message.
[0033] The information obtaining means may be operable to obtain said information from
said communications device as part of a procedure for establishing said radio bearer.
[0034] The information may comprise an indication that no further data is to be sent or
received by said communications device. The information may comprise an indication
that further data is to be sent or received by said communications device. In this case,
the further data may comprise data to be received, by said communications device, in
response to data sent by said communications device. The further data may also
comprise data requiring establishment of a user plane connection for said commu
nications device.
[0035] The obtaining means may be operable to obtain said information from said commu
nications device by receiving at least one RRC message at said base station. In this
case, the obtaining means may be operable to receive said at least one RRC message as
part of an RRC connection establishment procedure for said mobile communications
device. For example, the obtaining means may be operable to obtain said information
from at least one information element in said at least one RRC message.
[0036] The at least one RRC message may include at least one non-access stratum (NAS)
message. In this case, the obtaining means may be operable to obtain said information
from said at least one NAS message.
[0037] The data communicating means may be operable to receive said data as a data packet
in a payload of said at least one RRC message in which said information is provided by
said communications device. The data packet may require a response to be received at
said communications device, in which case said obtained information may indicate that
no further data is to be sent or received by said communications device after receipt of
said response. The data packet may comprise data sent in response to data previously
received by said communications device, in which case said obtained information may
indicate that no further data is to be sent or received by said communications device
after sending said response.
[0038] In one possibility, the base station may comprise said obtaining means. The obtaining
means may be operable to provide said obtained information to a core network entity.
[0039] The maintaining means may be operable to i) maintain said radio bearer if said in
formation indicates that further data is to be sent or received by said communications
device and ii) release said radio bearer if said obtained information indicates that no
further data is to be sent or received by said communications device.
[0040] The maintaining means may be operable to request said communications device to
establish a user-plane connection if said obtained information indicates that a userplane
connection is required by said communications device.
[0041] The maintaining means may be operable to request said communications device to
release said radio bearer if said obtained information indicates that no further data is to
be sent or received by said communications device.
[0042] The apparatus may comprise at least one of a base station and a mobility
management entity operating in accordance with long term evolution (LTE) standards.
[0043] In one aspect, the invention provides a communications device for providing in
formation to a network entity for use in determining whether a radio bearer should be
maintained or released, the communications device comprising a processor and a
transceiver The processor is configured to establish the radio bearer via a base station
of a communications system for sending or receiving data and the transceiver is
configured to send or receive data using the established radio bearer. The processor is
configured to determine at least one of: i) whether or not any further data is to be sent
or received by said communications device and ii) whether or not a user-plane
connection is required for said communications device; and to provide to the network
entity information identifying a result of said determination for use, by the network
entity, in determining whether the radio bearer should be maintained or released ac
cordingly.
[0044] In one aspect, the invention provides an apparatus for managing a radio bearer for a
communications device, the apparatus comprising a processor and a transceiver. The
transceiver is configured to communicate data with said communications device using
a radio bearer. The processor is configured to: obtain information from said commu
nications device, said information indicating, for the communications device, at least
one of: i) whether or not any further data is to be sent or received by said commu
nications device and ii) whether or not a user-plane connection is required by said
communications device; and determine, from said obtained information, whether the
radio bearer should be maintained or released; and maintain said radio bearer in de
pendence of said determination.
[0045] The invention also provides corresponding methods and a system comprising the
above communications device, the above base station, and the above mobility
management entity.
[0046] A further aspect of the present invention provides a computer program product
comprising computer implementable instructions for causing a programmable
computer device to become configured as a communications device, the base station,
or the mobility management entity as described above. The computer software
products may be provided on a carrier signal or on a recording medium, such as a CD,
DVD or the like.
Advantageous Effects of Invention
[0047] According to the present invention, it is possible to provide an improved
management of a connection release in case of small data transmissions by a MTC
device, and result in a more optimal usage of the overall resources of a communication
system.
Brief Description of Drawings
[0048] [fig.l]Fig. 1 illustrates schematically a cellular telecommunications system to which
embodiments of the invention may be applied;
[fig.2]Fig. 2 is a block diagram of a machine-type device forming part of the system
shown in Fig. 1;
[fig.3]Fig. 3 is a block diagram of a base station forming part of the system shown in
Fig. 1;
[fig.4]Fig. 4 is a block diagram of a mobility management entity forming part of the
system shown in Fig. 1;
[fig.5]Fig. 5 is an example timing diagram illustrating the provision of assistance in
formation during connection setup in a Mobile Originated small data transfer scenario;
and
[fig.6]Fig. 6 is another example timing diagram illustrating the provision of assistance
information during an information transfer procedure in a Mobile Terminated small
data transfer scenario.
Description of Embodiments
[0049] Overview
Fig. 1 schematically illustrates a telecommunications network 1 in which MTC
devices 2, mobile telephones 3, and other communications devices (not shown) can
communicate with each other or MTC service providers (e.g. an MTC server) via a
base station 5 and a core network 7 using an E-UTRA radio access technology (RAT).
As those skilled in the art will appreciate, whilst two MTC devices 2, two mobile
telephones 3, and one base station 5 are shown in Fig. 1 for illustration purposes, the
system, when implemented, will typically include other base stations and commu
nications devices.
[0050] The base station 5 is connected to the core network 7 via an S1 interface and to other
base stations via an X2 interface (not shown). The core network 7 includes a gateway 8
for connecting to other networks, such as the Internet and/or to servers hosted outside
the core network 7. It will be appreciated that the functionalities of the gateway 8 may
be split between two logical (and/or physical) entities. In this case, the gateway func
tionality for connecting the base station 5 (hence the MTC devices 2 and the mobile
telephones 3) to the core network 7 is carried out by a so-called serving gateway
(S-GW) entity whereas the gateway functionality for connecting to other (external)
networks is carried out by a so-called a packet data network (PDN) gateway, or simply
P-GW, entity.
[0051] A mobility management entity (MME) 9 is the network node responsible for keeping
track of the locations of the mobile communication devices (e.g. mobile telephones 3
and the MTC devices 2) within the communications network 1. In particular, the MME
9 stores an identifier of the mobile communication devices' last known cell (or tracking
area) so that they can be notified when there is an incoming (voice or data) call for
them and that a communication path is set up via the base station 5 currently serving
the particular mobile communication device.
[0052] A home subscriber server (HSS) 10 stores subscription related information and
control parameters specific for each communications device (e.g. the MTC devices 2
and the mobile telephones 3). The HSS 10 also stores information identifying which
ones of the communications devices are configured as machine-type communication
devices (e.g. the MTC devices 2 and/or a mobile telephone 3 when it is running an
MTC client) and provides this information to the other network entities when needed.
[0053] As explained above, the MTC devices 2 and mobile telephones 3 establish an RRC
connection with the base station 5 in order to be able to communicate with other
devices via that base station 5 (and the core network 7). The MTC devices 2 support
the small data transmission functionality so that their communications with other
devices can be carried out in an efficient manner and with minimal network impact.
[0054] In addition, the MTC devices 2 shown in Fig. 1 are also configured to provide a s
sistance information to the MME 9 in order to indicate any further expected commu
nications involving the MTC devices 2. The MME 9 may thus beneficially use the a s
sistance information provided by each MTC device 2 in its determination whether or
not to terminate the RRC connection (and possibly the SI connection) for that
particular MTC device 2.
[0055] Specifically, an MTC device 2 can provide at least one of the following types of a s
sistance information:
[0056] i) Information indicating that no further data is expected to be sent/received by/at the
MTC 2. In this case the MME 9 can beneficially instigate the release of the RRC and/
or SI connection immediately.
[0057] ii) Information indicating that the MTC device 2 expects to receive response data (i.e.
an acknowledgment) from another device/server. In this case the MME 9 maintains the
RRC and S1 connections for the MTC device 2 and waits for the response data.
However, the MME 9 can beneficially instigate the release the RRC and/or S1
connection for the MTC device 2 after receipt of the response data, e.g. without the
MTC device 2 having to send an indication described in point i) above. However, after
receipt of the response data, the MME 9 may also wait for further assistance in
formation and/or may take into account other information available to it before in
stigating the release of the RRC and/or S1 connection.
[0058] iii) Information indicating that user-plane establishment is expected/needed. If this
indication is given by the MTC device 2, the MME 9 maintains the RRC/S 1
connection for the MTC device 2. In this case, the MME 9 can beneficially trigger a
full service request for the establishment of the user-plane for the given MTC device 2.
In this case, the MME 9 may wait for further assistance information (such as in point i)
or ii) above) before instigating the release of the RRC and/or SI connection for the
MTC device 2.
[0059] Beneficially, the provision of assistance information from the MTC device 2 to the
MME 9 is achieved using NAS signalling. The NAS signalling carrying the assistance
information can be embedded in any suitable RRC message exchanged between the
MTC device 2 and the base station 5 so that it can be transmitted to the MME 9 r e
gardless whether the MTC device 2 is involved in a mobile originated or mobile
terminated small data transmission (and/or any other communication, such as regular
data transmissions).
[0060] In particular, the MTC device 2 includes any assistance information in an in
formation element in the form of a preference indication (e.g. a 'release preference in
dication' IE) which may be added to the NAS signalling message or the RRC message
carrying the NAS signalling message (or both). If the release preference indication IE
is included in the RRC message (i.e. the base station 5 can also read the release
preference indication IE), then the base station 5 can decide whether or not to release
the RRC/S1 connection for that MTC device 2 in accordance with the received
preference indication.
[0061] In any case, when the MME 9 receives the assistance information, and decides to
instigate the release of the RRC/S 1 connection for the MTC device 2, it informs the
base station 5 accordingly, which proceeds to release the applicable RRC/S 1
connection.
[0062] The provision of the MTC device's 2 release preference (which takes into account
any expected communication for/by that MTC device 2) can improve the decision
making process at the MME 9 (or the base station 5). Since the release preference is
based on information (expected communication) that may not be available to the
network entity controlling the RRC/S 1 connection, the provision of such assistance in
formation by the MTC device 2 can result in a more optimal usage of the overall
resources of the communication system 1. For example, the MTC devices 2 providing
their release preference to the MME 9 and/or the base station 5 may not be required to
send any keep-alive messages (or they may be required to send fewer keep-alive
messages than other communication devices) in order to maintain an RRC connection
with their serving base station 5.
[0063] MTC Device
Fig. 2 is a block diagram illustrating the main components of the MTC device 2
shown in Fig. 1. As shown, the MTC device 2 has a transceiver circuit 3 1 that is
operable to transmit signals to and to receive signals from a base station 5 via one or
more antenna 33. The MTC device 2 has a controller 37 to control the operation of the
mobile device 3. The controller 37 is associated with a memory 39 and is coupled to
the transceiver circuit 31. Although not necessarily required for its operation, the MTC
device 2 might of course have all the usual functionality of a conventional mobile
telephone 3 (such as a user interface 35) and this may be provided by any one or any
combination of hardware, software and firmware, as appropriate. Software may be preinstalled
in the memory 39 and/or may be downloaded via the telecommunications
network or from a removable data storage device (RMD), for example.
[0064] The controller 37 is configured to control overall operation of the MTC device 2 by,
in this example, program instructions or software instructions stored within memory
39. As shown, these software instructions include, among other things, an operating
system 41, a communications control module 43, an MTC module 45, a non-access
stratum module 47, and a radio resource control module 49.
[0065] The communications control module 43 controls the communication between the
MTC device 2 and other communications devices, such as other MTC devices 2,
mobile telephones 3, or the base station 5.
[0066] The MTC module 45 generates a release preference indication for sending to the
mobility management entity (or another network element). In particular, the MTC
module 45 obtains information from the communications control module 43 regarding
any expected communication by the MTC device 2 and generates the release
preference indication in dependence of the obtained information.
[0067] The non-access stratum module 47 exchanges NAS signalling messages with the
MME 9 (via the transceiver circuit 31). If a release preference is to be indicated in a
NAS message, the non-access stratum module 47 also includes the preference in
dication (obtained from the MTC module 45) in the NAS message (e.g. in an in
formation element) it sends to the MME 9.
[0068] The radio resource control module 49 exchanges RRC signalling messages with the
base station 5 (via the transceiver circuit 31). If requested to do so by the non-access
stratum module 47, the radio resource control module 49 includes any NAS message
(including any NAS IE) generated by the non-access stratum module 47 in the RRC
message it sends to the base station 5. If a release preference is to be indicated in an
RRC message, the radio resource control module 49 also includes the preference in
dication in the RRC message (e.g. in an information element in the RRC message) it
sends to the base station 5.
[0069] Base Station
Fig. 3 is a block diagram illustrating the main components of the base station 5
shown in Fig. 1. As shown, the base station 5 has a transceiver circuit 5 1 for
transmitting signals to and for receiving signals from the communications devices
(such as MTC devices 2 / mobile telephones 3) via one or more antenna 53, a core
network interface 55 for transmitting signals to and for receiving signals from the core
network 7. The base station 5 has a controller 57 to control the operation of the base
station 5. The controller 57 is associated with a memory 59.
[0070] The controller 57 is configured to control the overall operation of the base station 5
by, in this example, program instructions or software instructions stored within
memory 59. As shown, these software instructions include, among other things, an
operating system 61, a communications control module 63, an MTC assistance module
65, an SI module 67, and a radio resource control module 69.
[0071] The communications control module 63 controls the communication between the
base station 5 and the MTC devices 2, the mobile telephones 3 and other network
entities that are connected to the base station 5. The communications control module
63 also controls the separate flows of downlink user traffic and control data to be
transmitted to the communications devices associated with this base station 5
including, for example, control data for managing operation of the MTC devices 2 and/
or the mobile telephones 3.
[0072] The MTC assistance module 65 receives and handles assistance information from the
MTC device 2 including the release preference indication. The indication may be
received either via the RRC module 69 (if included in an RRC message from the MTC
device 2) or the SI module 67 (if sent via the MME 9, e.g. using NAS signalling).
[0073] The SI module 67 exchanges SI signalling messages with the MME 9 (via the
transceiver circuit 51). If the MME 9 requests the SI module 67 to do so, it proceeds to
release the SI connection for the MTC device 2 as requested by the MME 9.
[0074] The radio resource control module 69 exchanges RRC signalling messages with the
MTC device 2 (via the transceiver circuit 51). If the RRC message includes any NAS
message, the radio resource control module 69 forwards the NAS message (including
any NAS IE) to the MME 9 (via the SI module 67). If a release preference is indicated
in an RRC message received from an MTC device 2, depending on its configuration,
the radio resource control module 69 can either proceed to release the RRC connection
for that MTC device 2 in accordance with the received release preference indication or
forward the indication to the MME 9. If the MME 9 requests the radio resource control
module 69 to do so, it proceeds to release the RRC connection for the MTC device 2 as
requested by the MME 9.
[0075] Mobility Management Entity
Fig. 4 is a block diagram illustrating the main components of the mobility
management entity 9 shown in Fig. 1. As shown, the base station 5 has a transceiver
circuit 71 for transmitting signals to and for receiving signals from the other commu
nications devices (such as the MTC devices 2 / mobile telephones 3 / base stations 5 /
gateway 8) via a network interface 75. The mobility management entity 9 has a
controller 77 to control the operation of the mobility management entity 9. The
controller 77 is associated with a memory 79.
[0076] The controller 77 is configured to control the overall operation of the mobility
management entity 9 by, in this example, program instructions or software instructions
stored within memory 79. As shown, these software instructions include, among other
things, an operating system 81, a communications control module 83, an MTC a s
sistance module 85, a non-access stratum module 87, and an RRC/S1 control module
89.
[0077] The communications control module 83 controls the communication between the
mobility management entity 9 and the MTC devices 2 / mobile telephones 3 (i.e. via
the base station 5) and other network entities that are connected to the mobility
management entity 9.
The MTC assistance module 85 obtains assistance information relating to the MTC
device 2, including any release preference indication. In dependence of any obtained
preference indication (and/or any further information available to it), the MTC a s
sistance module 85 decides whether or not to maintain the RRC/Sl connection for the
MTC device 2. If the MTC assistance module 85 decides to release the RRC/Sl
connection, it informs the base station 5 (via the RRC/Sl control module 89) ac
cordingly.
[0078] The non-access stratum module 87 exchanges NAS signalling messages with the
MTC device 2 (via the transceiver circuit 71). If a release preference is received via a
NAS message, the non-access stratum module 87 provides the received preference in
dication to the MTC assistance module 85, also identifying which MTC device 2 sent
the preference indication.
[0079] The RRC/S 1 control module 89 manages the RRC and/or S1 connections for the
MTC devices 2 (and other communications devices) managed by this MME 9. The
RRC/S 1 control module 89 also controls the release of the RRC/S 1 connection in de
pendence of the decision made by the MTC assistance module 85.
[0080] In the above description, the MTC device 2, the base station 5, and the mobility
management entity 9 are described for ease of understanding as having a number of
discrete modules (such as the communications control modules and the MTC
modules). Whilst these modules may be provided in this way for certain applications,
for example where an existing system has been modified to implement the invention,
in other applications, for example in systems designed with the inventive features in
mind from the outset, these modules may be built into the overall operating system or
code and so these modules may not be discernible as discrete entities. These modules
may also be implemented in software, hardware, firmware or a mix of these.
[0081] Operation
A more detailed description will now be given (with reference to Fig. 5 and Fig. 6) of
the scenario discussed above where a UE comprising an MTC device 2 provides a s
sistance information to the mobility management entity 9 for controlling the release of
a connection for this MTC device 2.
[0082] Fig. 5 is an example timing diagram illustrating the provision of assistance in
formation during connection setup by the MTC device 2 (denoted 'UE'). This
procedure may be followed, for example, in case of a mobile originated (MO) small
data transmission scenario.
[0083] In this example, as shown in step s504, the MTC device 2 initially performs a
random access procedure with the base station 5 in order to be able to communicate
with the base station 5.
[0084] Once the MTC device 2 is granted communication resources during the random
access procedure, its RRC module 49 generates and sends, in step S506, a message requesting
the base station 5 to establish an RRC connection for/with the MTC device 2.
This 'RRC connection request' includes information identifying the MTC device 2 (e.g.
its S-Temporary Mobile Subscriber Identity (S-TMSI)) and an indication that the MTC
device 2 is configured to send/receive small data transmissions.
[0085] If the request by the MTC device 2 can be accommodated, the base station 5 (using
its RRC module 69) generates and sends an 'RRC Connection Setup' message, as
shown in step S508. After receiving this message, the MTC device 2 is ready to com
municate with other devices via this base station 5. Since the RRC connection has been
requested by the MTC device 2 for this purpose, this scenario can also be referred to as
a mobile originated communication scenario.
[0086] However, at this point the MME 9, the base station 5, and/or any other network entity
may not have information on the amount of data to be sent/received by this MTC
device 2.
[0087] Therefore, the MTC device 2 provides information to assist the MME 9 and/or the
base station 5 to manage the RRC connection that has been established in the
preceding step. This assistance information can also be used by the MME 9 and/or the
base station 5 to manage the S1 connection (between the base station 5 and the core
network 7) for communications by this MTC device 2.
[0088] Depending on the amount of data to be sent/received by the MTC device 2, the a s
sistance information may be provided in any one (or more) of the following ways:
[0089] i) If the MTC device 2 expects that no further data will be sent or received (i.e. other
than the data already included in this message), then it can provide a release preference
indication to indicate its preference for the MME 9 (or alternatively the base station 5)
to release the RRC and/or SI connection for the MTC device 2 immediately (or at any
point in time).
[0090] ii) If the MTC device 2 expects to receive response data (e.g. an acknowledgment)
from another communications device or an MTC server, then it can provide a release
preference indication to indicate its preference for the MME 9 (or alternatively the
base station 5) to keep the RRC/S1 connection alive and only release the connection(s)
after the response data is received.
[0091] iii) If the MTC device 2 expects/requires the establishment of a user-plane
connection (e.g. in order to send/receive data other than 'small data communications'
data), then it can a release preference indication to indicate its preference for the MME
9 (or alternatively the base station 5) to trigger a full service request for user-plane e s
tablishment.
[0092] As shown in Fig. 5, in case of an MO scenario, the MTC device 2 has two main
options to indicate its release preference.
[0093] In a first possibility denoted 'OPT A', the MTC device 2 (using its RRC module 49)
generates and sends, at step S510, a message to the base station 5 indicating that the
RRC connection has been set up (e.g. an 'RRC Connection Setup Complete' message).
The RRC module 49 also includes in this RRC message a NAS message generated by
the NAS module 47. This NAS message includes, amongst others, the MTC device's 2
release preference indication and the initial data packet ('UDP/IP packet') that the MTC
device 2 needs to send to another communications device (or server).
[0094] As shown in step S512, the base station 5 forwards the contents of the message
received at S510 to the MME 9. This is done by its SI module 67 generating and
sending a so-called 'Initial UE message' over the SI interface. This SI message
identifies (by its S-TMSI) the MTC device 2 for which the RRC connection has been
set up and also includes the NAS message carrying the MTC device's 2 release
preference indication and its initial data packet.
[0095] If the MTC device 2 follows this possibility, it may use any suitable NAS in
formation element to provide its release preference indication to the MME 9 or the
base station 5 via the MME 9 (e.g. a 'release preference indication' IE included in the
NAS message).
[0096] In a second possibility denoted 'OPT B', the MTC device 2 (using its RRC module
49) generates and sends, at step S520, an RRC message to the base station 5 indicating
that the RRC connection has been set up (e.g. an 'RRC Connection Setup Complete'
message). As in the previous possibility, the RRC module 49 includes in this RRC
message a NAS message generated by the NAS module 47 (and this NAS message
includes the MTC device's 2 initial data packet). However, rather than including its
release preference indication in the NAS message, the MTC device 2 includes its
release preference indication in the RRC message (generated by its RRC module 49).
The MTC device 2 may use any suitable RRC information element to provide its
release preference indication (e.g. a 'release preference indication' IE included in the
RRC message).
[0097] As shown in step S522, the base station 5 forwards the contents of the message
received at S520 to the MME 9. This is done by its SI module 67 generating and
sending a so-called 'Initial UE message' over the SI interface. This SI message
identifies (by its S-TMSI) the MTC device 2 for which the RRC connection has been
set up by the base station 5 and also includes the NAS message carrying the initial data
packet by the MTC device 2. Since the MME 9 is not able to handle RRC information
elements, the base station 5 includes the MTC device's 2 release preference indication
in a suitable information element within the SI message.
[0098] Regardless whether the first or second possibility is used, upon receipt of the Initial
UE message (at S512/S522) the MME 9 proceeds to setting up the connection for the
MTC device 2 in the core network 7 so that the MTC device 2 can send/receive data
packets to other communications devices and/or servers.
[0099] Therefore, in step S534, the MME 9 generates and sends a user-plane GPRS
Tunnelling Protocol (GTP-U) message to the gateway 8 serving the MTC device 2.
This GTP-U message also includes user-plane data, i.e. the initial data packet ('UDP/IP
packet') sent by the MTC device 2, which is then forwarded by the gateway 8 to its
intended recipient (at S536).
[0100] As generally shown at step S540, after the initial data packet has been transmitted,
the MME 9 or the base station 5 can start managing the RRC/S 1 connection for the
MTC device 2 in accordance with the received release preference indication.
[0101] If the received release preference comprises data transmissions of the type i) above,
then the MME 9 or the base station 5 can initiate release of the RRC/Sl connection im
mediately after the initial data packet has been successfully forwarded to the recipient
(or at least to the serving gateway 8), i.e. any time after step S534.
[0102] In case of a release preference indication of type ii), the MME 9 or the base station 5
can initiate the release of the RRC/Sl connection only after response data (e.g. an ac
knowledgement packet) for the initial data packet has been received by the MTC
device 2. Of course, until receipt of the response data, the MTC device 2 may send
further data packets and hence the RRC/S 1 connection should be preferably
maintained. However, in accordance with the release preference indication of type ii),
the MTC device 2 is not expected to send any further data packets after receipt of the
response data and hence the RRC/Sl connection can be released accordingly.
[0103] Finally, if the release preference indicated data transmissions of type iii), the MME 9
or the base station 5 does not initiate the release of the RRC/Sl connection until at
least receiving further indication from the MTC device 2 and/or fulfilment of other
release conditions (e.g. expiry of a user inactivity timer at the base station 5, receiving
a request from another network entity to release the RRC/S 1 connection, receiving an
error indication, data held at the MME 9 indicates that the connection can be released,
etc).
[0104] Fig. 6 is another example timing diagram illustrating the provision of assistance in
formation during an information transfer procedure between the MTC device 2 and the
mobility management entity 9. This procedure may be followed, for example, in case
of a mobile terminated (MT) small data transmission scenario.
[0105] As shown at step S600, the serving gateway 8 receives data for the MC device 2 (e.g.
from another communications device or a remote server). Therefore, in step S601, the
gateway 8 generates and sends to the MME 9 a message notifying the MME 9 about
the downlink data for the MTC device 2 ('Downlink Data Notification' message). The
gateway 8 includes in this message the data (e.g. 'UDP/IP packet') to be delivered to
the MTC device 2.
[0106] Upon receipt of the Downlink Data Notification message, the MME 9 initiates
paging of the MTC device 2, as shown in step S602, which is performed by the base
station 5 in step S603. If the data for the MTC device 2 is indicated to comprise data in
accordance with the small data transmissions functionality, the paging message for the
MTC device 2 also indicates this, e.g. by setting a flag (e.g. Small data flag) appro
priately. At this point, the downlink data for the MTC device 2 is temporarily stored in
the memory 79 of the MME 9 and awaits delivery to the MTC device 2 once an RRC
connection has been set up.
[0107] In response to the paging message, the MTC device 2 performs a random access
procedure with the base station 5, as shown in step S604, so that it can communicate
(i.e. receive the incoming data) via the base station 5.
[0108] Once the MTC device 2 is granted communication resources, its RRC module 49
generates and sends, in step S606, a message requesting the base station 5 to establish
an RRC connection for/with the MTC device 2. This 'RRC connection request'
includes information identifying the MTC device 2 (e.g. its S-TMSI).
[0109] Next, the base station 5 (using its RRC module 69) generates and sends an 'RRC
Connection Setup' message, as shown in step S608. After receiving this message, the
MTC device 2 is ready to communicate with other devices via this base station 5. Since
the RRC connection has been requested by the MTC device 2 in response to a paging
message indicating downlink data, this scenario can also be referred to as a mobile
terminated communication scenario.
[0110] The MTC device 2 confirms that the RRC connection has been successfully set up by
using its RRC module 49 to generate and send, at step S610, a message to the base
station 5 indicating that the RRC connection has been set up (e.g. an 'RRC Connection
Setup Complete' message). The MTC device 2 also includes in this RRC message an
indication of the service being requested, i.e. the delivery of download data indicated
by the preceding paging message.
[01 11] In response to this, as shown in step S612, the base station 5 (using its SI module 67)
generates and sends a message to the MME 9 (e.g. an 'Initial UE message'). This SI
message identifies (by its S-TMSI) the MTC device 2 for which the RRC connection
has been set up and also includes the service request received from the MTC device 2.
[01 12] Upon receipt of the message sent at step S612, the MME 9 processes the service
request and, using its NAS module 87, it generates a new NAS message to the MTC
device 2 and includes in this message, amongst others, the downlink data that is stored
in its memory 79. As shown in step S614, the MME 9 generates and sends a downlink
message (e.g. a 'Downlink NAS Transport' message) to the base station 5 over the SI
interface. This message includes the new NAS message carrying the downlink data for
the MTC device 2 and instructs the base station 5 to forward the NAS message to the
MTC device 2 over the RRC interface.
[0113] Accordingly, the base station 5 (using its RRC module 69) generates and sends an
RRC message to transfer the downlink data (e.g. a 'Downlink Information Transfer'
message) to the MTC device 2 - as shown in step S616. This RRC message includes
the NAS message generated by the MME 9 (which includes the data for the MTC
device 2).
[01 14] However, at this point the MME 9, the base station 5, and/or any other network entity
may not have information on the amount of data to be received (and/or sent) by this
MTC device 2 other than the initial data packet received at step S600.
[0115] Therefore, optionally, the MTC device 2 provides information to assist the MME 9
and/or the base station 5 to manage the RRC connection that has been established in
the preceding step. This assistance information can also be used by the MME 9 and/or
the base station 5 to manage the S1 connection (between the base station 5 and the core
network 7) for communications by this MTC device 2, as described above. However, if
the MTC device 2 does not have any data to send in response to the received downlink
data and/or it does not expect to receive any further downlink data, the MTC device 2
may skip the following steps and hence conserve its battery power. In this case, the
base station 5 and/or the MME 9 can still rely on conventional techniques to release
the RRC/S1 connection for this MTC device 2.
[0116] However, if the MTC device 2 does send assistance information, in case of an MT
scenario it has two main options to indicate its release preference, as shown in Fig. 6.
[01 17] In a first possibility denoted 'OPT C , the MTC device 2 (using its RRC module 49)
generates and sends, at step S620, a message to the base station 5 for sending uplink
data (e.g. an 'Uplink Information Transfer' message). The RRC module 49 also
includes in this message a new NAS message generated by the NAS module 47. This
NAS message includes, amongst others, the MTC device's 2 release preference in
dication and any response data ('UDP/IP response packet') that the MTC device 2
needs to send.
[0118] As shown in step S622, the base station 5 forwards the contents of the message
received at S620 to the MME 9. This is done by its SI module 67 generating and
sending a so-called 'Uplink NAS Transport' message over the SI interface. This SI
message includes the new NAS message carrying the MTC device's 2 release
preference indication and its response data packet.
[01 19] If the MTC device 2 follows this possibility, it may use any suitable NAS in
formation element to provide its release preference indication to the MME 9 or the
base station 5 via the MME 9 (e.g. a 'release preference indication' IE included in the
NAS message).
[0120] In a second possibility denoted 'OPT D', the MTC device 2 (using its RRC module
49) generates and sends, at step S630, a message to the base station 5 for sending
uplink data (e.g. an 'Uplink Information Transfer' message). As in the previous pos
sibility, the RRC module 49 includes in this RRC message the new NAS message
generated by the NAS module 47 (and this NAS message includes the MTC device's 2
response data packet). However, rather than including its release preference indication
in the NAS message, the MTC device 2 includes its release preference indication in the
RRC message (generated by its RRC module 49). The MTC device 2 may use any
suitable RRC information element to provide its release preference indication (e.g. a
'release preference indication' IE included in the RRC message).
[0121] As shown in step S632, the base station 5 forwards the contents of the message
received at S630 to the MME 9. This is done by its SI module 67 generating and
sending a so-called 'Uplink NAS Transport' message over the SI interface. This SI
message thus includes the NAS message carrying the response data packet by the MTC
device 2. Since the MME 9 is not able to handle RRC information elements, the base
station 5 includes the MTC device's 2 release preference indication in a suitable in
formation element within the SI message.
[0122] Steps S634 to S640 generally correspond to steps S534 to S540, respectively, hence
their description is omitted for simplicity.
[0123] The above exemplary embodiments may result in improved management of the
(RRC/S1) connection release in case of small data transmissions by the MTC device.
This is achieved by considering information provided by the MTC device 2 (or an
MTC application of a mobile telephone 3), which is normally not available at the
network nodes. By taking into account the assistance information from the MTC
device 2, the SI and RRC connections can be advantageously:
- released immediately by the network if it has been indicated that no further
transmission from the MTC device 2 is expected;
- kept active if it has been indicated that the MTC device 2 is expecting confirmation;
and
- maintained and regular user-plane establishment be triggered if it is indicated that
additional small data transmissions are expected by the MTC device 2.
[0124] Since the release preference is based on information (expected communication) that
may not be available to the network entity controlling the RRC/S1 connection, the
provision of such assistance information by the MTC device 2 can result in a more
optimal usage of the overall resources of the communication system 1.
[0125] Modifications and Alternatives
Detailed embodiments have been described above. As those skilled in the art will ap
preciate, a number of modifications and alternatives can be made to the above em
bodiments whilst still benefiting from the inventions embodied therein. By way of illustration
only a number of these alternatives and modifications will now be described.
[0126] It will be appreciated that whilst embodiments of the invention have been described
with particular reference to the control of machine-type data connections (e.g. the
release of a radio connection used for the transmission of a relatively small amount of
data), the provision of assistance information (release preference indication) may
benefit any other applications in which assistance information may be used to control
the release of a connection for a communications device. For example, the above em
bodiments may be applicable for transmitting user data, backup data, synchronisation
data, diagnostic data, monitoring data, usage statistics, error data and/or the like.
[0127] In the above description, an MME was given as an example NAS entity commu
nicating with the MTC device (and/or the mobile telephone). However, it will be ap
preciated that the release preference indication may be provided to any other NAScapable
communications entity, e.g. a Serving GPRS Support Node (SGSN) within (or
coupled to) the core network.
[0128] Although the above embodiments describe the MTC device providing assistance in
formation to the MME (in the form of a release preference indication), it will be ap
preciated that any MTC-capable mobile telephone (i.e. a mobile telephone running an
MTC client and/or supporting the small data transmission functionality) may also
provide such assistance information.
[0129] The above embodiments describe specific examples for the MTC device to provide
assistance information to the base station / MME serving the MTC device. However, it
will be appreciated that the release preference indication may be provided using any
suitable IE and/or any signalling message other than the NAS/RRC/S1 messages
described above. It will also be appreciated that the release preference indication may
be included in any part of the NAS/RRC/S1 message.
[0130] In the above description, the release preference indication given by the MTC device
is described to relate to an existing communication (e.g. small data transmission) by
the MTC device. However, it will be appreciated that this preference may relate to any
future communications by the MTC device (i.e. until an updated preference indication
is provided overriding any previous preference). It will also be appreciated that a
separate preference may be indicated for MO and MT communications within the same
or in different signalling messages. In particular, any one or more of the above
described options A to D may be used in combination.
[0131] Further, it will be appreciated that the MTC device's release preference may
comprise a default setting (either as a default factory configuration or as an ap
plication/subscriber specific setting). The default setting may be provided, for
example, by the MTC device and/or the HSS and/or any other network entity either as
part of the above described procedures or independently. If a default setting is used, it
will be appreciated that the MTC device may only indicate its release preference only
if a release preference other than the default one is to be applied for a particular com
munication by the MTC device. Thus, in the absence of an explicit release preference,
the base station / MME may apply the default release preference for communications
by the MTC device.
[0132] In the above embodiments, the base station is described to obtain the MTC device's
preference indication from an information element included in the RRC part of the
message sent from the MTC device to the MME. However, it will also be appreciated
that the base station may obtain the MTC device's preference indication from the MME
(i.e. indirectly) if this indication is included in the NAS part of the message sent by the
MTC device (which the base station may not be able to access). This may be beneficial
for network operators wishing to maintain control of the RRC/S 1 release procedure at
the base station rather than the MME irrespective of the type of information element
used by the MTC device.
[0133] In the above description of Fig. 5 and Fig. 6, steps S540 and S640 are shown to take
place only after the initial data packet has been transmitted from the MME to the
gateway. However, it will be appreciated that steps S540/S640 may also take place as
soon as the release preference indication is received from the MTC device and/or may
take place at different time for the base station and the MME, depending on when they
obtain the MTC device's release preference indication (e.g. after step S510/S520 in
case of the base station and after step S512/S522 in case of the MME).
[0134] In the above embodiments, a 3GPP radio communications (radio access) technology
is used. However, any other radio communications technology (i.e. WLAN, Wi-Fi,
WiMAX, Bluetooth, etc.) can be used by the MTC device in accordance with the
above embodiments. The above embodiments are also applicable to 'non-mobile' or
generally stationary user equipment.
[0135] Examples of MTC applications
Some examples of machine type communication applications are listed in the
following table (source: 3GPP TS 22.368, Annex B). This list is not exhaustive and is
intended to be indicative of the scope of machine type communication applications.
Service Area MTC applications
Surveillance systems
Backup for landline
Security
Control of physical access (e.g. to buildings)
Car/driver security
Fleet Management
Order Management
Pay as you drive
Asset Tracking
Tracking & Tracing
Navigation
Traffic information
Road tolling
Road traffic optimisation/steering
Point of sales
Payment Vending machines
Gaming machines
Monitoring vital signs
Supporting the aged or handicapped
Health
Web Access Telemedicine points
Remote diagnostics
Sensors
Lighting
Pumps
Remote Maintenance/Control Valves
Elevator control
Vending machine control
Vehicle diagnostics
Power
Gas
Water
Metering
Heating
Grid control
Industrial metering
Digital photo frame
Consumer Devices Digital camera
eBook
In the above description, the MTC device, the base station, and the mobility
management entity are described for ease of understanding as having a number of
discrete functional components or modules. Whilst these modules may be provided in
this way for certain applications, for example where an existing system has been
modified to implement the invention, in other applications, for example in systems
designed with the inventive features in mind from the outset, these modules may be
built into the overall operating system or code and so these modules may not be discernible
as discrete entities.
[0137] In the above embodiments, a number of software modules were described. As those
skilled in the art will appreciate, the software modules may be provided in compiled or
un-compiled form and may be supplied to the MTC device, to the mobile telephone, to
the base station or to the mobility management entity as a signal over a computer
network, or on a recording medium. Further, the functionality performed by part or all
of this software may be performed using one or more dedicated hardware circuits.
However, the use of software modules is preferred as it facilitates the updating of the
MTC device (or the mobile telephone having an MTC application), the base station,
the mobility management entity in order to update their functionalities.
[0138] Various other modifications will be apparent to those skilled in the art and will not be
described in further detail here.
[0139] The above-mentioned processing may be executed by a computer. Also, it is possible
to provide a computer program which causes a programmable computer device to
execute the above-mentioned processing. The program can be stored and provided to a
computer using any type of non-transitory computer readable media. Non-transitory
computer readable media include any type of tangible storage media. Examples of nontransitory
computer readable media include magnetic storage media (such as floppy
disks, magnetic tapes, hard disk drives, etc.), optical magnetic storage media (e.g.
magneto-optical disks), CD-ROM, CD-R, CD-R/W, and semiconductor memories
(such as mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash
ROM, RAM (Random Access Memory), etc.). The software modules may be provided
to a computer using any type of transitory computer readable media. Examples of
transitory computer readable media include electric signals, optical signals, and elec
tromagnetic waves. Transitory computer readable media can provide the software
modules to a computer via a wired communication line (e.g. electric wires, and optical
fibers) or a wireless communication line.
[0140] This application is based upon and claims the benefit of priority from United
Kingdom Patent Application No. 1309074.1, filed on May 20, 2013, the disclosure of
which is incorporated herein in its entirely by reference.
Reference Signs List
[0141] 1 TELECOMMUNICATIONS NETWORK
2 MTC DEVICE
3 MOBILE TELEPHONE
5 BASE STATION
7 CORE NETWORK
8 GATEWAY
MOBILITY MANAGEMENT ENTITY (MME)
HOME SUBSCRIBER SERVER (HSS)
TRANSCEIVER CIRCUIT
ANTENNA
USER INTERFACE
CONTROLLER
MEMORY
OPERATING SYSTEM
COMMUNICATIONS CONTROL MODULE
MTC MODULE
NON-ACCESS STRATUM MODULE
RADIO RESOURCE CONTROL MODULE
TRANSCEIVER CIRCUIT
ANTENNA
CORE NETWORK INTERFACE
CONTROLLER
MEMORY
OPERATING SYSTEM
COMMUNICATIONS CONTROL MODULE
MTC ASSISTANCE MODULE
SI MODULE
RADIO RESOURCE CONTROL MODULE
TRANSCEIVER CIRCUIT
NETWORK INTERFACE
CONTROLLER
MEMORY
OPERATING SYSTEM
COMMUNICATIONS CONTROL MODULE
MTC ASSISTANCE MODULE
NON-ACCESS STRATUM MODULE
RRC/S1 CONTROL MODULE

Claims
A communications device for providing information to a network entity
for use in determining whether a radio bearer should be maintained or
released, the communications device comprising:
means for establishing the radio bearer via a base station of a commu
nications system for sending or receiving data;
means for sending or receiving data using the established radio bearer;
means for determining at least one of:
i) whether or not any further data is to be sent or received by said com
munications device; and
ii) whether or not a user-plane connection is required for said commu
nications device; and
means for providing to the network entity information identifying a
result of said determination for use, by the network entity, in de
termining whether the radio bearer should be maintained or released ac
cordingly.
The communications device according to claim 1 wherein said means
for sending or receiving data is operable to send or receive said data as
a data packet in a payload of a control plane message.
The communications device according to claim 2 wherein said means
for sending or receiving data is operable to send or receive said data as
a data packet in a payload of a radio resource control, RRC, message.
The communications device according to claim 3 wherein said means
for sending or receiving data is operable to send said data as a data
packet in a payload of an uplink information transfer message or
receive said data as a data packet in a payload of a downlink in
formation transfer message.
The communications device according to claim 3 wherein said means
for sending or receiving data is operable to send or receive said data as
a data packet in a payload of an RRC connection setup complete
message.
The communications device according to any of claims 1 to 5 wherein
said information providing means is operable to provide said in
formation identifying a result of said determination to said network
entity as part of a procedure for establishing said radio bearer.
The communications device according to any of claims 1 to 6 wherein
when said determining means is operable to determine that no further
PCT7JP2014/002604
data is to be sent or received by said communications device, said in
formation identifying a result of said determination comprises an in
dication that no further data is to be sent or received by said commu
nications device.
The communications device according to any of claims 1 to 6 wherein
when said determining means is operable to determine that further data
is to be sent or received by said communications device, said in
formation identifying a result of said determination comprises an in
dication that further data is to be sent or received by said commu
nications device.
The communications device according to claim 8 wherein said further
data comprises data to be sent in response to data received by said com
munications device.
The communications device according to claim 8 or 9 wherein said
further data comprises data requiring establishment of a user plane
connection for said communications device.
The communications device according to any of claims 1 to 10 wherein
said providing means is operable to provide said information
identifying a result of said determination to said network entity by
sending at least one RRC message to said base station.
The communications device according to claim 11 wherein said
providing means is operable to send said at least one RRC message as
part of an RRC connection establishment procedure.
The communications device according to claim 12 wherein said
providing means is operable to provide said information identifying a
result of said determination using at least one information element in
said at least one RRC message.
The communications device according to claim 12 or 13 wherein said
at least one RRC message includes at least one non-access stratum,
NAS, message.
The communications device according to claim 14 wherein said
providing means is operable to provide said information identifying a
result of said determination using said at least one NAS message.
The communications device according to any of claims 1 1 to 15
wherein said means for sending or receiving data is operable to send
said data as a data packet in a payload of said at least one RRC message
in which said information identifying a result of said determination is
provided to said network entity.
PCT7JP2014/002604
The communications device according to claim 16 wherein said data
packet requires a response to be received at said communications
device and wherein said information identifying a result of said deter
mination indicates that no further data is to be sent or received by said
communications device after receipt of said response.
The communications device according to claim 16 wherein said data
packet comprises data sent in response to data received by said commu
nications device and wherein said information identifying a result of
said determination indicates that said communications device expects
no further data to be sent or received after sending said data packet.
The communications device according to any of claims 1 to 18 wherein
said providing means is operable to send said information identifying a
result of said determination to said base station.
The communications device according to any of claims 1 to 19 wherein
said providing means is operable to send said information identifying a
result of said determination to a core network entity.
The communications device according to claim 20 wherein said
providing means is operable to send said information identifying a
result of said determination to said base station via said core network
entity.
The communications device according to any of claims 1 to 2 1
comprising at least one of a machine-type communications device, a
mobile telephone, and user equipment operating in accordance with
long term evolution, LTE, standards.
An apparatus for managing a radio bearer for a communications device,
the apparatus comprising:
means for communicating data with said communications device using
a radio bearer;
means for obtaining information from said communications device,
said information indicating, for the communications device, at least one
of:
i) whether or not any further data is to be sent or received by said com
munications device; and
ii) whether or not a user-plane connection is required by said commu
nications device;
means for determining, from said obtained information, whether the
radio bearer should be maintained or released; and
means for maintaining said radio bearer in dependence of said deterPCT7JP2014/
002604
mination.
The apparatus according to claim 23 wherein said data communicating
means is operable to send or receive said data as a data packet in a
payload of a control plane message.
The apparatus according to claim 24 wherein said data communicating
means is operable to send or receive said data as a data packet in a
payload of a radio resource control, RRC, message.
The apparatus according to claim 25 wherein said data communicating
means is operable to send said data as a data packet in a payload of a
downlink information transfer message or receive said data as a data
packet in a payload of an uplink information transfer message.
The apparatus according to claim 25 wherein said data communicating
means is operable to receive said data as a data packet in a payload of
an RRC connection setup complete message.
The apparatus according to any of claims 23 to 27 wherein said in
formation obtaining means is operable to obtain said information from
said communications device as part of a procedure for establishing said
radio bearer.
The apparatus according to any of claims 23 to 28 wherein said in
formation comprises an indication that no further data is to be sent or
received by said communications device.
The apparatus according to any of claims 23 to 29 wherein said in
formation comprises an indication that further data is to be sent or
received by said communications device.
The apparatus according to claim 30 wherein said further data
comprises data to be received, by said communications device, in
response to data sent by said communications device.
The apparatus according to claim 30 or 31 wherein said further data
comprises data requiring establishment of a user plane connection for
said communications device.
The apparatus according to any of claims 23 to 32 wherein said
obtaining means is operable to obtain said information from said com
munications device by receiving at least one RRC message at said base
station.
The apparatus according to claim 33 wherein said obtaining means is
operable to receive said at least one RRC message as part of an RRC
connection establishment procedure for said mobile communications
device.
WO 2014/188694 PCT7JP2014/002604
[Claim 35] The apparatus according to claim 34 wherein said obtaining means is
operable to obtain said information from at least one information
element in said at least one RRC message.
[Claim 36] The apparatus according to claim 34 or 35 wherein said at least one
RRC message includes at least one non-access stratum, NAS, message.
[Claim 37] The apparatus according to claim 36 wherein said obtaining means is
operable to obtain said information from said at least one NAS
message.
[Claim 38] The apparatus according to claim 36 or 37 wherein said data commu
nicating means is operable to receive said data as a data packet in a
payload of said at least one RRC message in which said information is
provided by said communications device.
[Claim 39] The apparatus according to claim 38 wherein said data packet requires
a response to be received at said communications device and wherein
said obtained information indicates that no further data is to be sent or
received by said communications device after receipt of said response.
[Claim 40] The apparatus according to claim 38 wherein said data packet
comprises data sent in response to data previously received by said
communications device and wherein said obtained information
indicates that no further data is to be sent or received by said commu
nications device after sending said response.
[Claim 41] The apparatus according to any of claims 23 to 40 wherein said base
station comprises said obtaining means.
[Claim 42] The apparatus according to any of claims 23 to 4 1 wherein said
obtaining means is operable to provide said obtained information to a
core network entity.
[Claim 43] The apparatus according to any of claims 23 to 42 wherein said
maintaining means is operable to i) maintain said radio bearer if said
information indicates that further data is to be sent or received by said
communications device and ii) release said radio bearer if said obtained
information indicates that no further data is to be sent or received by
said communications device.
[Claim 44] The apparatus according to claim 43 wherein said maintaining means is
operable to request said communications device to establish a userplane
connection if said obtained information indicates that a userplane
connection is required by said communications device.
[Claim 45] The apparatus according to claim 43 wherein said maintaining means is
operable to request said communications device to release said radio
WO 2014/188694 PCT7JP2014/002604
bearer if said obtained information indicates that no further data is to be
sent or received by said communications device.
[Claim 46] The apparatus according to any of claims 23 to 44 comprising at least
one of a base station and a mobility management entity operating in ac
cordance with long term evolution, LTE, standards.
[Claim 47] A communications device for providing information to a network entity
for use in determining whether a radio bearer should be maintained or
released, the communications device comprising a processor and a
transceiver, wherein:
the processor is configured to establish the radio bearer via a base
station of a communications system for sending or receiving data;
the transceiver is configured to send or receive data using the e s
tablished radio bearer;
the processor is configured to determine at least one of:
i) whether or not any further data is to be sent or received by said com
munications device; and
ii) whether or not a user-plane connection is required for said commu
nications device; and
the processor is configured to provide to the network entity information
identifying a result of said determination for use, by the network entity,
in determining whether the radio bearer should be maintained or
released accordingly.
[Claim 48] An apparatus for managing a radio bearer for a communications device,
the apparatus comprising a processor and a transceiver, wherein:
the transceiver is configured to communicate data with said commu
nications device using a radio bearer;
the processor is configured to:
obtain information from said communications device, said information
indicating, for the communications device, at least one of:
i) whether or not any further data is to be sent or received by said com
munications device; and
ii) whether or not a user-plane connection is required by said commu
nications device; and
determine, from said obtained information, whether the radio bearer
should be maintained or released; and
maintain said radio bearer in dependence of said determination.
[Claim 49] A system comprising the communications device according to any of
claims 1 to 22 and the apparatus according to any of claims 23 to 46.
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[Claim 50] A method performed by a communications device for providing in
formation to a network entity for use in determining whether a radio
bearer should be maintained or released, the method comprising:
establishing the radio bearer via a base station of a communications
system for sending or receiving data;
sending or receiving data using the established radio bearer;
determining at least one of:
iii) whether or not any further data is to be sent or received by said
communications device; and
iv) whether or not a user-plane connection is required for said commu
nications device; and
providing to the network entity information identifying a result of said
determination for use, by the network entity, in determining whether
the radio bearer should be maintained or released accordingly.
[Claim 51] A method performed by a network apparatus for managing a radio
bearer for a communications device, the method comprising:
communicating data with said communications device using a radio
bearer;
obtaining information from said communications device, said in
formation indicating, for the communications device, at least one of:
iii) whether or not any further data is to be sent or received by said
communications device; and
iv) whether or not a user-plane connection is required by said commu
nications device; and
determining, from said obtained information, whether the radio bearer
should be maintained or released; and
maintaining said radio bearer in dependence of said determination.
[Claim 52] A computer implementable instructions product comprising computer
implementable instructions for causing a programmable commu
nications device to perform the method according to claim 50 or 51.