Infrastructure equipment, mobile communications network and method for reducing overhead of signaling transmissions and processing

Abstract

A communications device establishes a communications context for communicating data packets using a packet communications bearer from the communications device via a mobile communications network. A controller of the communications device is configured to identify that the communications device can enter a stasis state because no data packets are available for transmission for a predetermined time via the packet communications bearer or there are no data packets to receive via the packet communications bearer, to transmit a stasis state message to the mobile communications network, and to store information relating to the communications context associated with the packet communications bearer in a data store. The stored information can be used by the controller to re-establish the packet communications bearer to transmit and/or receive data packets using the packet communications bearer, the communications device thereby entering the stasis state.

What is claimed is: 
     
         1 . An infrastructure equipment for forming part of a mobile communications network, the infrastructure equipment comprising:
 a transmitter unit configured to transmit data to communications devices via a wireless access interface,   a receiver unit configured to receive data transmitted from communications devices via the wireless access interface, and   a controller configured to control the transmitter unit and the receiver unit to form the wireless access interface,   to receive one or more signalling messages from a communications device and in response to establish a communications context for communicating data packets via a packet communications bearer via the mobile communications network,   to receive a stasis state message from the communications device for which the context has been established, the stasis state message indicating that the communications device wishes to enter a stasis state because no data packets are available for transmission for a predetermined time via the packet communications bearer,   to transmit a stasis state confirm message to the communications device, and   to store information relating to the communications context established for the communications devices and associated with the packet communications bearer in a data store, which stored information can be used by the controller to re-establish the same packet communications bearer to transmit data packets via the same packet communications bearer, the communications device thereby entering the stasis state.   
     
     
         2 . An infrastructure equipment as claimed in  claim 1 . wherein the controller is configured in response to the stasis state message to store, with the information relating to the communications context, a network terminal identifier provided to the communications device for requesting communications resources when the communications context was established,
 receiving a request to re-connect message from the communications device, the request to re-connect message including the network terminal identifier,   in response to receiving the request to re-connect message from the communications device the controller is configured   to recognise the network terminal identifier,   to retrieve the information relating to the communications context of the communications device from the data store,   to re-establish the communications context of the communications device, to communicate data packets received from the communications device via the wireless access interface and the mobile communications network via the packet communications bearer.   
     
     
         3 . An infrastructure equipment as claimed in  claim 1 , wherein the information relating to the communications context which is stored by the controller in the data store includes one or more sequence numbers associated with one or more protocols of a protocol stack which forms the packet communications bearer to the effect that, when the communications device moves from the stasis state to the connected state, the stored sequence numbers can be restored to the one or more protocols of the protocol stack to transmit or receive data packets via the wireless access interface and the packet communications bearer. 
     
     
         4 . An infrastructure equipment as claimed in  claim 3 , wherein the information relating to the context which is stored by the controller in the data store includes one or more of a sequence number associated with a radio link control protocol, a packet data communications protocol or a configuration of a medium access control layer. 
     
     
         5 . An infrastructure equipment as claimed in  claim 3 , wherein the information relating to the context which is stored by the controller in the data store includes a sequence number and a cyphering key associated with a sequence context. 
     
     
         6 . An infrastructure equipment as claimed in  claim 1 , wherein the infrastructure equipment is configured to operate in accordance with a 3GPP Long Term Evolution network, the terminal identification number of the communications device being an Cell-Radio Network Terminal Identifier, C-RNTI, and the packet communications bearer is an Enhanced Packet System communications bearer. 
     
     
         7 . A mobile communications network including an infrastructure equipment as claimed in  claim 1 . 
     
     
         8 . A method of communicating data packets from an infrastructure equipment via a mobile communications network, the method comprising:
 receiving one or more signalling messages from a communications device, in response to the received signalling messages establishing a communications context for communicating data packets using a packet communications bearer via the mobile communications network,   receiving a stasis state message from the communications device for which the context has been established, the stasis state message indicating that the communications device wishes to enter a stasis state because no data packets are available for transmission for a predetermined time via the packet communications bearer,   transmitting a stasis state confirm message to the communications device, and   storing information relating to the communications context established for the communications devices and associated with the packet communications bearer in a data store, which stored information can be used by the controller to re-establish the packet communications bearer to transmit data packets using the packet communications bearer, the communications device thereby entering the stasis state.   
     
     
         9 . A method as claimed in  claim 8 , wherein the storing information relating to the communications context established for the communications devices comprises
 in response to the stasis state message storing, with the information relating to the communications context, a network terminal identifier provided to the communications device for requesting communications resources when the communications context was established,   receiving a request to re-connect message from the communications device, the request to re-connect message including the network terminal identifier, and   in response to receiving the request to re-connect message from the communications device,   recognising the network terminal identifier,   retrieving the information relating to the communications context of the communications device from the data store, and   re-establishing the communications context of the communications device, to communicate data packets received from the communications device via the wireless access interface and the mobile communications network via the packet communications bearer.   
     
     
         10 . A method as claimed in  claim 8 , wherein the storing information relating to the communications context established for the communications devices and associated with the packet communications bearer in a data store comprises
 storing in the data store one or more sequence numbers associated with one or more protocols of a protocol stack which forms the packet communications bearer to the effect that, when the communications device moves from the stasis state to the connected state, the stored sequence numbers can be restored to the one or more protocols of the protocol stack to transmit or receive data packets via the wireless access interface and the packet communications bearer.   
     
     
         11 . A mobile communications system comprising a mobile communications network as claimed in  claim 7  providing a wireless access interface for communicating with the communications device, and a communications device for transmitting data to and receiving data from the mobile communications network, the communications device comprising:
 a transmitter unit configured to transmit signals to the mobile communications network via the wireless access interface provided by the mobile communications network, and 
 a receiver unit configured to receive signals from the mobile communications network via the wireless access interface provided by the mobile communications network, and 
 a controller configured to control the transmitter unit to transmit one or more signalling messages to the communications network and the receiver unit to receive one or more signalling messages from the communications network to establish a communications context for communicating data packets using a packet communications bearer from the communications device via the mobile communications network, wherein the controller is configured 
 to identify that the communications device can enter a stasis state because no data packets are available for transmission for a predetermined time via the packet communications bearer or there are no data packets to receive via the packet communications bearer, 
 to transmit a stasis state message to the mobile communications network, and 
 to store information relating to the communications context associated with the packet communications bearer in a data store, which stored information can be used by the controller using the transmitter unit and the receiver unit to re-establish the packet communications bearer to transmit and/or receive data packets using the packet communications bearer, the communications device thereby entering the stasis state.