Patent Publication Number: US-2020280363-A1

Title: Mobile communications device and system

Description:
TECHNICAL FIELD 
     The present invention relates to mobile communications system and to mobile devices and networks, particularly but not exclusively those operating according to the 3GPP (Third Generation Partnership Project) standards or equivalents or derivatives thereof. The invention has particular although not exclusive relevance to the Long Term Evolution (LTE) of UTRAN (called Evolved Universal Terrestrial Radio Access Network (E-UTRAN)), for example as currently defined in 3GPP standards documentation TS 23.401 (SA2), 36.300, 36.331 (RAN2). 36.413 (RAN3), 24.301, 27.007 (CT1), and 29.272 (CT4). 
     BACKGROUND ART 
     Relaying is considered for LTE-Advanced as a tool to improve, for example, the coverage of high data rates for User Equipment (UE), group mobility, temporary network deployment, cell edge throughput and/or to provide coverage in new cell areas. E-UTRAN supports relaying by having a Relay Node (RN) wirelessly connected to a base station (eNB) (referred to as a Donor eNB (DeNB)). In addition to serving its own ‘donor’ cell, the DeNB serves the RN, via a modified version of the E-UTRA radio interface. The modified interface is referred to as the ‘Un’ interface or the ‘RN-Un’ interface. Although the RN may be fixed or mobile, it is, nevertheless, a base station and is provided with many aspects of a base station&#39;s functionality and is therefore capable of acting as a base station serving UE in its own ‘relay’ cell via a wireless interface referred to as the ‘RN-Uu’ interface. From the perspective of the UE in the relay cell, therefore, the RN essentially appears to be a conventional LTE base station. 
     SUMMARY OF INVENTION 
     Technical Problem 
     Nevertheless, situations may well arise where a UE cannot properly communicate with either a base station or an RN. For example, various factors, such as environment, path loss, power limitation, may limit cell coverage, or, indeed, the UE may be in an environment, where communication with the base station or RN is very problematic. At recent 3GPP meetings, it has been proposed, for public safety purposes to utilize specially configured UEs themselves as relays for other UEs. For example, as discussed at 3GPP TSG-SA WG1 Meeting #56 in San Francisco, Calif., 14-18 Nov. 2011 and described in documents S1-113135, S1-113143 and S1-113144 (3GPP TR 22.8xx V0.1.0), a UE can be enabled for Proximity-based Services (ProSe). Such a ProSe enabled UE could be able to act for safety purposes as a relay of direct communication towards the network for UEs unable to access the network. A safety enabled UE without access to the network but with ProSe access to another UE with relay capability and with access to the network would be able to interact with that UE to establish direct communication for relay. Of course, ProSe functionality has been concerned, in general, with communication between UEs that are in proximity to each other and may enable social networking applications between them. 
     The present invention therefore seeks to provide a system and a mobile device that provide efficient relay configuration. 
     Solution to Problem 
     Accordingly, in a first aspect, the invention provides a method of providing relay capabilities in a wireless communication system, the method comprising receiving mobile device relaying capability information about a particular mobile device, updating at a network controller of the communications system, a stored context for the particular mobile device with the mobile device relaying capability information for that mobile device indicating that the particular mobile device can be used as a relay for relaying communications for another mobile device, and configuring the wireless communication system to enable the particular mobile device to be used to provide relay functionality based on the updated stored context to relay communications for another mobile device. 
     In one preferred embodiment, after receiving the mobile device relaying capabilities about a particular mobile device, the method comprises checking whether a user of the particular mobile device has granted consent to the use of the particular mobile device as a relay and only updating the stored context that the particular mobile device can be used as a relay, if the user has granted consent. 
     The consent to the use of the particular mobile device as a relay may be provided in subscription information for the particular mobile device stored in a home subscriber server for the particular mobile device. 
     The method may further comprise obtaining relaying subscription information about the particular mobile device from the home server if the consent has been granted. 
     In an embodiment, the user can change whether consent to the use of the particular mobile device as a relay is given, and may be able to temporarily change consent that has been given. 
     The mobile device relaying capability information may comprise network-level mobile device relaying capabilities, which may comprise a level of relay capability indicating whether the particular mobile device can be used for all communications or for only a subset of communications. The network-level mobile device relaying capabilities may be received in a Non-Access Stratum (NAS) message. 
     The mobile device relaying capability information may comprise radio-level relaying capabilities about the particular mobile device, which may be received in an Access Stratum (AS) message. 
     The method may further comprise utilizing the particular mobile device as a relay for communications to another mobile device based at least in part on the mobile device relaying capability information. 
     According to another aspect, the present invention provides a mobile communications device for use in a communications system, comprising means for communicating mobile device relaying capability information to a communications node of the communications system, and means for providing relay communications for another mobile device. 
     The relay communications may be provided between another mobile device and either the communications node or another relay device of the communications system. 
     The mobile device relaying capability information may comprise network-level mobile device relaying capabilities, which may comprise a level of relay capability indicating whether the particular mobile device can be used for all communications or for only a subset of communications. The network-level mobile device relaying capabilities may be transmitted in a Non-Access Stratum (NAS) message and may be communicated during registration with the communications node. 
     The mobile device relaying capability information may comprise radio-level relaying capabilities about the particular mobile device, which may be transmitted in an Access Stratum (AS) message. 
     The radio-level relaying capabilities may comprise information regarding any one or more of supported carrier frequencies, supported frequency bands and supported radio access technologies. 
     The radio-level capability information may be communicated following a device capability enquiry during registration with the communications node. The network-level mobile device relaying capabilities may be communicated during registration with the communications node. 
     In one embodiment the mobile communications device may further comprise means for temporarily disabling the means for providing relay communications for another mobile device. The means for temporarily disabling the means for providing relay communications for another mobile device may comprise a user interface or an AT (Terminal Equipment to Terminal Adaptor) command interface. 
     In a further aspect, the invention provides a network controller for use in a wireless communication system, the network controller comprising means for receiving mobile device relaying capability information about a particular mobile device, means for updating a stored context for the particular mobile device with the mobile device relaying capability information for that mobile device indicating that the particular mobile device can be used as a relay for relaying communications for another mobile device, and means for configuring the wireless communication system to enable the particular mobile device to be used to provide relay functionality based on the updated stored context to relay communications for another mobile device. 
     The network controller may further comprise means for checking whether a user of the particular mobile device has granted consent to the use of the particular mobile device as a relay and only updating the stored context that the particular mobile device can be used as a relay, if the user has granted consent. 
     The mobile device relaying capability information may comprise network-level mobile device relaying capabilities, which may comprise a level of relay capability indicating whether the particular mobile device can be used for all communications or for only a subset of communications. 
     The mobile device relaying capability information may comprise radio-level relaying capabilities about the particular mobile device. 
     A further aspect of the invention provides a base station for use in a wireless communication system, the base station comprising means for receiving mobile device relaying capability information about a particular mobile device, means for forwarding the mobile device relaying capability information to a network controller of the wireless communication system, means for receiving, from the network controller, a request for radio-level relaying capabilities about the particular mobile device, means for obtaining radio-level relaying capabilities from the particular mobile device, and means for forwarding the radio-level relaying capabilities obtained from the particular mobile device to the network controller. 
     Another aspect of the invention provides a subscriber server for use in a wireless communication system, the subscriber server comprising means for receiving, from a network controller, a request for information about a particular mobile device, means for checking whether a user of the particular mobile device has granted consent to the use of the particular mobile device as a relay, and means for forwarding relaying information for that particular mobile device if the user has granted consent. 
     According to a further aspect, the invention provides a communications system comprising a communications node for communicating with at least one mobile device, a mobile device as described above, and a network controller as described above coupled to the communications node. The communications system may further comprise a base station as described above and/or a subscriber server as described above. 
     As used herein, a mobile device may be a mobile telephone device, such as a UE in a 3GPP system, a netbook, laptop computer, or any other mobile electronic device configured to transmit and receive data (whether voice or other) on a wireless network. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to at least provide a system and a mobile device that provide efficient relay configuration. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  schematically illustrates a mobile telecommunication system of a type to which the embodiment is applicable. 
         FIG. 2  shows a flow diagram illustrating, in general terms, a procedure for registration of a mobile device in the mobile telecommunication system of  FIG. 1 . 
         FIG. 3  shows a flow diagram illustrating, in general terms, a procedure for modifying consent in the mobile telecommunication system of  FIG. 1 . 
         FIG. 4  shows a flow diagram illustrating, in general terms, a procedure for updating radio access relaying capabilities in the mobile telecommunication system of  FIG. 1 . 
         FIG. 5  is a block diagram illustrating the main components of the base station illustrated in  FIG. 1 . 
         FIG. 6  schematically illustrates a mobile device for use in the system shown in  FIG. 1 . 
         FIG. 7  shows a flow diagram illustrating, in general terms, a procedure for updating network level mobile device relaying capabilities in the mobile telecommunication system of  FIG. 1 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the invention will now be more fully described, by way of example, with reference to the drawings. 
     Thus,  FIG. 1  schematically illustrates a mobile (cellular) telecommunication system  1  in which users of mobile devices  2  can communicate with other users (not shown) via a base station  3  and a telephone network  4 . As shown in  FIG. 1 , the base station  3  is directly connected to the core network  4 . The system may be a 3GPP LTE system, where the mobile devices are known as User Equipment (UE) and the core network includes a Mobile Management Entity, MME,  5 , which is coupled to a Home Subscriber Server, HSS,  6 , which may, or may not be within the core network  4 . However, the system need not be a 3GPP LTE system, but may be a 2G or 3G system, where the MME may be replaced by a Serving GPRS Support Node (SGSN), for example. However, the present embodiment will be further described in the context of a 3GPP LTE system. 
     Accordingly, as shown schematically in  FIG. 1 , the UE  2  is too far away, or in an environment where it cannot (or cannot properly) communicate directly with the base station  3 . Therefore, another UE that is in a location where it can communicate directly with both the base station  3  and the UE  2  is used as a relay for the communications between the UE  2  and the base station  3 . The relaying UE (known as UE-R)  7  thereby improves the coverage of the base station to enable the network to provide communication coverage for UEs that are not in good direct communication with a base station. 
     In order to allow the network to properly utilize such UE-Rs in an efficient way (for example, to have a sufficient cell deployment and optimal resource usage), the network should know which UEs are capable of providing a relay function to relay data to/from other UEs. Since not all UEs may have such relaying functionality, the network needs to know the relaying capabilities of a UE-R, including whether it has any relaying functionality and, if so, the level of relaying functionality that it is capable of and the UE radio capabilities, so that the network can configure the UE-R according to the required network deployment. 
       FIG. 2  shows a schematic flow diagram of a registration procedure for a UE with relay capability, such as UE-R  7 , when it first registers with a network  4 . As can be seen, the UE-R sends an Attach Request message (as is known) via the Non-Access Stratum (NAS) via the base station  3  (in this case the evolved NodeB (eNB) base station, to the MME  5 . In a 3GPP LTE network, the role of the eNB  3  (which is part of the Radio Access Network) is to transmit/receive the data and signaling between the Core Network  4  and the UEs  2  which are under its radio cell coverage. The UEs  2  need to transmit/receive data and/or signaling to/from the eNB  3  whenever a communication is required (for example, to register, update registration, establish a data session, or a voice call). When registering with the network  4 , a UE  2  sends UE Network Capabilities to the MME  5  in order for the MME  5  to know how to configure communications with the UE  2 . UE Network Capabilities may include general UE Non Access Stratum characteristics to provide the network with information concerning aspects of the UE related to Evolved Packet System or interworking with GPRS. The contents might affect the manner in which the network handles the operation of the UE. In current 3GPP TS 24.301, the UE Network Capabilities includes information about UE EPS supported security algorithms, and UE support of Single Radio Voice Call Continuity. In one embodiment, the UE  2  stores Network-level UE Relaying Capabilities together with the UE Network Capabilities and forwards them to the MME in the NAS Attach Request. The Network-level UE relaying Capabilities includes information regarding the relaying capabilities of the UE, which may affect the manner in which the network utilizes the relay operation using that UE, for example, whether the UE can be used as a relay for emergencies and/or for other uses. Of course, the Network-level UE relaying Capabilities need not be sent in the NAS Attach Request message, but could be sent via any other NAS level information message or using other messages. The Network-level UE relaying Capabilities can be sent to the MME during the NAS registration procedure, or be included in other NAS messages sent by the UE. The Network-level UE relaying Capabilities are then stored in the Core Network  4  (e.g. the MME  5 ) in order to be able to use the relaying functionality of the UE-R  7 . 
     The MME  5 , upon receiving the NAS Attach Request message, performs a UE Update Location procedure with the HSS  6  by sending an Update Location Request to the HSS  6 . At this point, according to a preferred embodiment, the HSS  6  determines whether the user of the UE has given consent for the UE to be used by the network for relaying purposes. Such consent may be included in subscriber relaying information stored together with Subscriber Information in the HSS  6 . If, upon receipt of the Update Location Request message, the HSS  6  determines that the user has such consent from the user of the UE for the UE to be used as a relay for other UEs, the subscriber relaying information can be made available by the HSS  6  to the MME  5  for storage in the MME  5 . It will be apparent that the subscriber information can be associated with the IMSI number of the UE and the HSS  6  may store, associated with the IMSI a field that indicates whether the subscriber has consented to the relaying function. If the field indicates that such consent has been given, then relaying subscription data can be stored in a further field associated with the IMSI and this further subscription data would then be accessible by the HSS  6  to transmit to the MME  5 . If the consent field indicates that consent has not been given, then the relaying subscription data field may not be accessible. Of course, if desired, the system could be set up such that the relaying subscription data may be made available in the event of an emergency irrespective of whether consent has been given or not, but may not be so set up. Accordingly, if the HSS  6  determines that access to the relaying subscription information may be granted, it sends that information to the MME  5 , possibly in an Update Location Acknowledgement message. 
     The MME  5  then saves the Subscription Information, including the relaying subscription information received from the HSS  6  in a context for the UE-R  7  and transmits an S1 Initial Context Setup Request to the eNB  3 . During initial registration, the context for that UE-R  7  would be empty, so the eNB  3  requests Radio-level Access Capabilities from the UE-R  7 , which provides its Radio-level Access Capabilities, including Radio-level Relaying Capabilities, back to the eNB  3 , which transmits them back to the MME  5 , where they are stored in the UE-R context. The Radio-level Relaying Capabilities comprises information at radio AS (Access Stratum) level and generally includes information regarding supported carrier frequencies, supported frequency bands and/or supported radio access technologies, such as 3GPP and/or non-3GPP radio access technologies. This information is used by the network to configure the radio bearers of both the UEs and the UE-Rs for relaying purposes. For example, a non-3GPP technology could be used for the relaying function if both the relaying and the relayed UEs support it. Alternatively, if a network operator decides to use dedicated bands for relaying, the eNB must take into account both the dedicated bands and the UE-Rs relaying radio capabilities, when configuring the UEs and UE-Rs for relaying. The Radio-level Relaying Capabilities may be included in the UE&#39;s Radio-level Access Capabilities container and signaled in a Radio Resource Control (RCC) message by the UE to the eNB. Such an RRC message may be the UE Capability Information message that is sent in response to a UE Capability Enquiry sent by the eNB. 
     As mentioned above, both the Network-level UE relaying Capabilities and the Radio-level Relaying Capabilities are stored in the MME in the Core Network, together with the Subscription Information from the HSS for the particular UE-R. The consent given or not given by the subscriber owning a particular UE to its use as a UE-R can be changed, of course. If, for example, the subscriber wishes to withdraw consent to the use of the UE as a UE-R, as shown in  FIG. 3 , the subscriber can contact the Service Provider, either by an internet web server interface, SMS, voice call or in any other suitable manner, to advise the Operator Server that consent has been withdrawn. In such a case, the Operator Server updates the HSS field associated with the UE IMSI and the HSS updates the MME with the information that the consent has been withdrawn. The MME then updates the UE context by marking it as no longer being available for use as a UE-R, for example, if the MME itself stores the consent in the UE context, or by removing the Subscription Information from the UE context altogether. 
       FIG. 5  is a block diagram illustrating the main components in the base station  3  shown in  FIG. 1 . As shown, the base station  3  includes a transceiver circuit  11  which is operable to transmit signals to, and to receive signals from, UEs over a conventional Uu interface via at least one antenna  12 . The base station  3  is also operable to transmit signals to and to receive signals from the core network  4  via a network interface  13 . The operation of the transceiver circuit  11  is controlled by a controller  14  in accordance with software stored in memory  15 . 
     The software includes, among other things, an operating system  16 , a communications control module  17  including a relay module  18 , and a UE context maintenance module  19 . 
     The communications control module  17  is operable to control communication with UEs and UE-Rs including, for example, allocation of resources to be used by the transceiver circuit  11  in its communications with the UEs and the UE-Rs. The communications control module  17  also schedules the times for the transmission of downlink data to the UEs and UE-Rs. The relay module  18  of the control module  17  controls the configuration of the UEs that are to be used as UE-Rs and configuration of UE-Rs, as well as the communications with UE-Rs that are being used as relays for communications with other UEs. 
     A UE context maintenance module  19  maintains the context of the UE-R  7  as received from the MME  5  to allow the base station  3  to carry out device identity mapping, and to provide the various relay capabilities to the relay module  18 , as needed. 
       FIG. 6  schematically illustrates the main components of each mobile device  7  shown in  FIG. 1 . As shown, the mobile device  7  includes transceiver circuitry  21  which is operable to transmit signals to and to receive signals from the base station  3  via one or more antennas  22 . As shown, the mobile device  7  may includes a controller  23  which controls the operation of the mobile device  7  and which may be connected to the transceiver circuit  21  and may further be connected to a loudspeaker  24 , a microphone  25 , a display  26 , and a keypad  27 . The controller  23  operates in accordance with software instructions stored within memory  28 . As shown, these software instructions include, among other things, an operating system  29 , a reporting module  30 , a handover module  31  and a relay module  32 . 
     In this embodiment: the reporting module  30  is operable to report the occurrence of specified events back to the serving base station  3 , the handover module  31  is operable to control the handover of the mobile device  7  from one cell to another and the relay module  32  is operable to control and configure the functionality of the UE as a UE-R. In one embodiment, the UE-R  7  can allow a user of the UE-R to temporarily disable relay functionality, for example to reduce power consumption. This can be done, for example, by the relay module  32  providing the user with relay ON/OFF capability via a user interface formed by at least the display  26  and keypad  27  so that the user can turn off the relay functionality without changing the consent status at the HSS. The relay module  32  interfaces between the application layer (the user interface) and the NAS so that NAS updates any impacted Network-level UE relaying Capabilities in the UE. An AT command (being a command from Terminal Equipment (TE), such as a computer, to a Terminal Adaptor (TA)) could be used to enable or disable relay functionality, for example. The AT command could be used for configuring Mobile Termination relaying functions from TE to a TA. Any affected NAS (or AS) capabilities for the relaying function would then be updated according to the user choice. Any updates to the Network-level UE relaying Capabilities will also be transferred to the MME, as will be further described below. 
       FIG. 4  illustrates a scenario where the UE-R configuration is updated via a User Interface or AT command. If the change impacts the UE radio relaying capabilities, then the MME is informed via a NAS Tracking Area Update procedure in which an “Update of the radio capability information needed” bit is set. The MME thus triggers the eNB to fetch from the UE-R updated Radio-level Access Capabilities, including Radio-level Relaying Capabilities, which are then uploaded to the MME and updated in the UE context. 
     Similarly, as shown in  FIG. 7 , if the UE-R configuration is updated via a User Interface or AT command and the change impacts the Network-level UE relaying Capabilities, then the MME is informed via the NAS Tracking Area Update procedure including the updated Network-level UE relaying Capabilities further to which the MME updates the UE context. 
     It will be seen, therefore, that various embodiments allow the network to determine the relay capabilities of any relay capable UEs based on the Network-level UE relaying Capabilities provided by such UEs. This allows the network to operate more efficiently. A user can change the relay capabilities of the UE-R temporarily and such changes are notified to the network, where they can be taken into account in determining relaying. Since the user may also need to grant consent to the use of the UE as a UE-R, which consent is included in the subscriber information, a user can more permanently change whether the UE is permitted to be used for relay functions. Since the network knows which UEs are UE-Rs and their relaying capabilities, it can use such UE-Rs to increase the coverage of the network. This could be independent of any subscription and/or roaming rights of the user of the UE-R being so used, since the network can configure the UE to be used as a UE-R, as needed based on the requirements of the network configuration/policy and the capabilities of nearby UEs which require relaying. It is also possible for such network configuration of UE-Rs to be carried out irrespective of whether consent by the user has been granted, for example in the case of emergencies. 
     It will be appreciated that although only one particular embodiment of the invention has been described in detail, various modifications and improvements can be made by a person skilled in the art without departing from the scope of the present invention. For example, it is possible for consent to be granted or withheld at different levels of relay capability. It may be, that a user is willing to grant consent for use for emergency purposes only, or for only certain uses, or for all uses. For example, if the user belongs to a particular group of users, consent may be given for relaying capabilities to be provided between mobile devices or users belonging to that group, but not for other users or devices. Such consent to particular levels of relaying capability may be included in the Subscription Information and stored in the HSS, as described above, and the MME is then only authorized to utilize the UE-R according to the level of relaying capability for which consent has been granted, but not for any other level of relaying capability. 
     This application is based upon and claims the benefit of priority from United Kingdom Patent Application No. 1201915.4, filed on Feb. 3, 2012, the disclosure of which is incorporated herein in its entirety by reference. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be applied to a method of providing mobile communications system and to mobile devices and networks. 
     REFERENCE SIGNS LIST 
     
         
           1  MOBILE (CELLULAR) TELECOMMUNICATION SYSTEM 
           2  MOBILE DEVICES (UE) 
           3  BASE STATION (eNB) 
           4  CORE NETWORK 
           5  MOBILE MANAGEMENT ENTITY (MME) 
           6  HOME SUBSCRIBER SERVER (HSS) 
           7  MOBILE DEVICES (UE: KNOWN AS UE-R) 
           11  TRANSCEIVER CIRCUIT 
           12  ANTENNA 
           13  NETWORK INTERFACE 
           14  CONTROLLER 
           15  MEMORY 
           16  OPERATING SYSTEM 
           17  CONTROL MODULE 
           18  RELAY MODULE 
           19  UE CONTEXT MAINTENANCE MODULE 
           21  TRANSCEIVER CIRCUIT 
           22  ANTENNAS 
           23  CONTROLLER 
           24  LOUDSPEAKER 
           25  MICROPHONE 
           26  DISPLAY 
           27  KEYPAD 
           28  MEMORY 
           29  OPERATING SYSTEM 
           30  REPORTING MODULE 
           31  HANDOVER MODULE 
           32  RELAY MODULE