Communication system

Abstract

A gateway is described which facilitates a change of communication cell for a mobile device in a communication system, which includes a core network. The gateway receives messages from a base station operating a cell and forwards the messages received from the base station to the core network. The gateway intercepts a message relating to a change of communication cell, from a source cell in which the mobile communication device is located to a target cell, to determine if the core network needs to be notified of the change of cell. When it is determined that the core network needs to be notified, the gateway generates a message for providing information relating to the change of cell to the core network and transmits the message to the core network.

1 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the gateway apparatus comprising:
 a receiver configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   an interceptor configured to intercept and process said message relating to said change of communication cell to determine if said communication entity in the core network needs to be notified of information relating to said change of communication cell;   a generator configured to generate, when it is determined that said communication entity in the core network needs to be notified of information relating to said change of communication cell, a message for providing said information relating to said change of communication cell to said core network entity; and   a transmitter configured to transmit, to said communication entity in the core network, said message for providing said information relating to said change of communication cell;   wherein each of the receiver, the interceptor, the generator, and the transmitter are implemented by a hardware processor.   
     
     
         2 . Gateway apparatus according to  claim 1  wherein said interceptor is operable to determine whether or not said message relating to said change of communication cell should be forwarded to said communication entity in the core network. 
     
     
         3 . Gateway apparatus according to  claim 2  wherein said interceptor is operable to determine whether messages relating to a change of communication cell should be forwarded to said communication entity in the core network based on a number of cell changes that have occurred since messages relating to a change of communication cell were previously forwarded to said communication entity in the core network. 
     
     
         4 . Gateway apparatus according to  claim 3  said interceptor is operable to determine that messages relating to a change of communication cell should not be forwarded to said communication entity in the core network when the number of cell changes that have occurred since messages relating to a change of communication cell were previously forwarded to said communication entity in the core network has not exceeded a predetermined value. 
     
     
         5 . Gateway apparatus according to  claim 3  said interceptor is operable to determine that messages relating to a change of communication cell should be forwarded to said communication entity in the core network when the number of cell changes that have occurred since messages relating to a change of communication cell were previously forwarded to said communication entity in the core network has reached or exceeded the predetermined value. 
     
     
         6 . Gateway apparatus according to  claim 1  wherein said generator is operable to generate, responsive to said message relating to said change of communication cell, a further message for progressing said change of communication cell; and said transmitter is operable to transmit said further message for progressing said change of communication cell to said source base station or to said target base station. 
     
     
         7 . Gateway apparatus according to  claim 6  wherein said generator is operable to generate said further message for progressing said change of communication cell without forwarding the message relating to said change of communication cell to the communication entity in the core network. 
     
     
         8 . Gateway apparatus according to  claim 6  wherein said generator is operable to generate said further message for progressing said change of communication cell based on information obtained by said interceptor from messages previously forwarded to or from said communication entity in said core network. 
     
     
         9 . Gateway apparatus according to  claim 1 , wherein said interceptor is operable to determine if said communication entity in the core network needs to be notified of information relating to said change of communication cell comprising location information; and wherein said message for providing said information relating to said change of communication cell to said communication entity in the core network comprises a location report for providing said location information. 
     
     
         10 . Gateway apparatus according to  claim 1  wherein said interceptor is operable to determine if said communication entity in the core network needs to be notified of information relating to said change of communication cell comprising information identifying communication bearers that the target base station has failed to set up; and wherein said message for providing said information relating to said change of communication cell to said communication entity in the core network comprises a message identifying said communication bearers that the target base station has failed to set up. 
     
     
         11 . Gateway apparatus according to  claim 10  wherein said receiver is operable to receive, from said communication entity in the core network in response to said message identifying said communication bearers that the target base station has failed to set up, a message for initiating a modification in a communication parameter for communication by said mobile communication device in said target cell. 
     
     
         12 . Gateway apparatus according to  claim 11  wherein said message for initiating a modification in a communication parameter is configured to initiate a change in an aggregate maximum bit rate. 
     
     
         13 . Gateway apparatus according to  claim 1  wherein said interceptor is operable to determine, from a message relating to said change of communication cell received from said source base station, whether direct data forwarding is possible for at least one communication bearer of said mobile communication device. 
     
     
         14 . Gateway apparatus according to  claim 13  wherein said generator is operable to generate, responsive to said determination of whether direct data forwarding is possible, a message indicating whether direct data forwarding is possible for sending to said target base station. 
     
     
         15 . Gateway apparatus according to  claim 13  wherein said generator is operable to generate, responsive to a determination that direct data forwarding is possible, a message comprising parameters for establishing a direct communication tunnel for forwarding data directly between said source and target base stations. 
     
     
         16 . Gateway apparatus according to  claim 13  wherein said gateway apparatus is operable, responsive to a determination that direct data forwarding is not possible, to facilitate establishment of an indirect communication tunnel for forwarding data indirectly between said source and target base stations via said gateway apparatus. 
     
     
         17 . Gateway apparatus according to  claim 16  wherein said gateway apparatus is operable to facilitate said establishment of an indirect communication tunnel using a tunnel creation request and a corresponding response message. 
     
     
         18 . Gateway apparatus according to  claim 1  wherein said gateway apparatus is operable to terminate messages related to said change of communication cell, received from said source base station or from said target base station and destined for said communication entity in the core network, without forwarding them to said communication entity in the core network. 
     
     
         19 . Gateway apparatus according to  claim 1  wherein said gateway apparatus is a small cell gateway apparatus. 
     
     
         20 . Gateway apparatus according to  claim 1  wherein said gateway apparatus comprises at least one of a home base station gateway (HeNB-GW) function, a security gateway (SeGW), and an X2 gateway (X2-GW) function. 
     
     
         21 . Gateway apparatus according to  claim 1  wherein said communication entity in the core network is a mobility management entity (MME). 
     
     
         22 . Gateway apparatus according to  claim 1  wherein each said base station comprises a low power node (LPN) operating a small cell. 
     
     
         23 . Gateway apparatus according to  claim 1  wherein said at least one message relating to said change of communication cell is a message in accordance with the S1 application protocol (S1AP). 
     
     
         24 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus comprising:
 a storage, implemented by a memory, the storage being configured to store at the gateway apparatus, context information for the mobile communication device relating to a communications connection between the mobile communication device and a source base station that operates a source cell in which said mobile communication device is located;   a receiver configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   a generator configured to generate at least one further message for progressing said change of communication cell responsive to said at least one message relating to said change of communication cell using said context information; and   a transmitter configured to transmit, to at least one of said source base station and said target base station, said at least one further message for progressing said change of communication cell;   
       wherein each of the receiver, the generator, and the transmitter are implemented by a hardware processor. 
     
     
         25 . Gateway apparatus according to  claim 24  wherein said at least one further message for progressing said change of communication cell comprises a message for transferring said context information to said target base station. 
     
     
         26 . Gateway apparatus according to  claim 24  wherein said context information comprises security context information relating to the communications connection between the mobile communication device and the source base station. 
     
     
         27 . Gateway apparatus according to  claim 26  wherein said gateway apparatus is operable to determine whether or not to initiate the transfer of said context information, including said security context information, based on a number of cell changes that have occurred since the security context information was last updated. 
     
     
         28 . Gateway apparatus according to  claim 27  wherein said gateway apparatus is operable to determine to initiate the transfer of said context information, including said security context information, when the number of cell changes that have occurred since the security context information was last updated has not exceeded a predetermined value. 
     
     
         29 . Gateway apparatus according to  claim 27  wherein said gateway apparatus is operable to determine not to initiate the transfer of said context information, including said security context information, when the number of cell changes that have occurred since the security context information was last updated has reached or exceeded said predetermined value. 
     
     
         30 . Gateway apparatus according to  claim 29  wherein said gateway apparatus is operable to initiate an update to said security context information when the number of cell changes that have occurred since the security context information was last updated has reached or exceeded said predetermined value. 
     
     
         31 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the gateway apparatus comprising:
 a receiver configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   an interceptor configured to intercept and process said message relating to said change of communication cell to determine whether said message relating to a change of communication cell should be forwarded to said communication entity in the core network based on a number of cell changes that have occurred since messages relating to a change of communication cell were previously forwarded to said communication entity in the core network;   a generator configured to generate, when it is determined that said message relating to a change of communication cell should not be forwarded to said communication entity in the core network, a further message for progressing said change of communication cell;   a transmitter configured to transmit, when it is determined that said message relating to a change of communication cell should not be forwarded to said communication entity in the core network, to said source base station or to said target base station, said further message for progressing said change of communication cell; and   a forwarded configured to forward said message relating to a change of communication cell to said communication entity in the core network, when it is determined that said message relating to a change of communication cell should be forwarded to said communication entity in the core network;   wherein each of the receiver, the interceptor, the generator, the transmitter and the forwarder are implemented by a hardware processor.   
     
     
         32 . A gateway apparatus for configured to facilitate change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the gateway apparatus comprising:
 a receiver configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   an interceptor configured to intercept and process said message relating to said change of communication cell to determine, from a message relating to said change of communication cell received from said source base station, whether direct data forwarding is possible for at least one communication bearer of said mobile communication device;   a generator configured to generate, responsive to said determination of whether direct data forwarding is possible, a message indicating whether direct data forwarding is possible for sending to said target base station; and   a transmitter configured to transmit, said message indicating whether direct data forwarding is possible to said target base station;   wherein each of the receiver, the interceptor, the generator, and the transmitter are implemented by a hardware processor.   
     
     
         33 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the gateway apparatus comprising a processor and transceiver circuitry, wherein:
 said transceiver circuitry is configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   said processor is configured to:
 i) intercept and process said message relating to said change of communication cell to determine if said core network entity needs to be notified of information relating to said change of communication cell; and 
 ii) generate, when it is determined that said communication entity in the core network needs to be notified of information relating to said change of communication cell, a message for providing said information relating to said change of communication cell to said communication entity in the core network; and 
   said transceiver circuitry is configured to transmit, to said communication entity in the core network, said message for providing said information relating to said change of communication cell.   
     
     
         34 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus comprising a processor, a memory, and transceiver circuitry, wherein:
 said processor is configured to store in said memory context information for the mobile communication device relating to a communications connection between the mobile communication device and a source base station that operates a source cell in which said mobile communication device is located;   said transceiver circuitry is configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   said processor is configured to generate at least one further message for progressing said change of communication cell responsive to said at least one message relating to said change of communication cell using said context information; and   said transceiver circuitry is configured to transmit, to at least one of said source base station and said target base station, said at least one further message for progressing said change of communication cell.   
     
     
         35 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the gateway apparatus comprising a processor and transceiver circuitry, wherein:
 said transceiver circuitry is configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   said processor is configured to:
 i) intercept and process said message relating to said change of communication cell to determine whether said message relating to a change of communication cell should be forwarded to said communication entity in the core network based on a number of cell changes that have occurred since messages relating to a change of communication cell were previously forwarded to said communication entity in the core network; and 
 ii) generate, when it is determined that said message relating to a change of communication cell should not be forwarded to said communication entity in the core network, a further message for progressing said change of communication cell; 
   said transceiver circuitry is configured to transmit, when it is determined that said message relating to a change of communication cell should not be forwarded to said communication entity in the core network, to said source base station or to said target base station, said further message for progressing said change of communication cell; and   said transceiver circuitry is configured to forward said message relating to a change of communication cell to said communication entity in the core network, when it is determined that said message relating to a change of communication cell should be forwarded to said communication entity in the core network.   
     
     
         36 . A gateway apparatus configured to facilitate a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the gateway apparatus comprising a processor and transceiver circuitry, wherein:
 said transceiver circuitry is configured to receive, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   said processor is configured to:
 i) intercept and process said message relating to said change of communication cell to determine, from a message relating to said change of communication cell received from said source base station, whether direct data forwarding is possible for at least one communication bearer of said mobile communication device; and 
 generate, responsive to said determination of whether direct data forwarding is possible, a message indicating whether direct data forwarding is possible for sending to said target base station; and 
   said transceiver circuitry is configured to transmit, said message indicating whether direct data forwarding is possible to said target base station.   
     
     
         37 . A communication system comprising a gateway apparatus according to  claim 1 , at least one mobile communication device, a source base station and a target base station. 
     
     
         38 . A method performed by a gateway apparatus for facilitating a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the method comprising:
 receiving, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   intercepting and processing said message relating to said change of communication cell to determine if said communication entity in the core network needs to be notified of information relating to said change of communication cell;   generating, when it is determined that said communication entity in the core network needs to be notified of information relating to said change of communication cell, a message for providing said information relating to said change of communication cell to said communication entity in the core network; and   transmitting, to said communication entity in the core network, said message for providing said information relating to said change of communication cell.   
     
     
         39 . A method performed by a gateway apparatus for facilitating a change of communication cell for a mobile communication device in a communication system, the method comprising:
 storing, at the gateway apparatus, context information for the mobile communication device relating to a communications connection between the mobile communication device and a source base station that operates a source cell in which said mobile communication device is located;   receiving, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   generating at least one further message for progressing said change of communication cell responsive to said at least one message relating to said change of communication cell using said context information; and   transmitting, to at least one of said source base station and said target base station, said at least one further message for progressing said change of communication cell.   
     
     
         40 . A method performed by a gateway apparatus for facilitating a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the method comprising:
 receiving, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   intercepting and processing said message relating to said change of communication cell to determine whether said message relating to a change of communication cell should be forwarded to said communication entity in the core network based on a number of cell changes that have occurred since messages relating to a change of communication cell were previously forwarded to said communication entity in the core network;   generating, when it is determined that said message relating to a change of communication cell should not be forwarded to said communication entity in the core network, a further message for progressing said change of communication cell; transmitting, when it is determined that said message relating to a change of communication cell should not be forwarded to said communication entity in the core network, to said source base station or to said target base station, said further message for progressing said change of communication cell; and   forwarding said message relating to a change of communication cell to said communication entity in the core network, when it is determined that said message relating to a change of communication cell should be forwarded to said communication entity in the core network.   
     
     
         41 . A method performed by a gateway apparatus for facilitating a change of communication cell for a mobile communication device in a communication system, the gateway apparatus being operable to receive messages from at least one base station operating a respective cell of said communication system and to forward the messages received from the at least one base station to a communication entity in a core network, the method comprising:
 receiving, from at least one of a source base station that operates a source cell in which said mobile communication device is located and a target base station that operates a target cell for said change of communication cell, at least one message relating to said change of communication cell;   intercepting and processing said message relating to said change of communication cell to determine, from a message relating to said change of communication cell received from said source base station, whether direct data forwarding is possible for at least one communication bearer of said mobile communication device;   generating, responsive to said determination of whether direct data forwarding is possible, a message indicating whether direct data forwarding is possible for sending to said target base station; and   transmitting, said message indicating whether direct data forwarding is possible to said target base station.   
     
     
         42 . A computer implementable instructions product comprising computer implementable instructions for causing a programmable communications device to perform the method of  claim 38 .