Physical-layer system prioritization and communication session management within a wireless communications system

Abstract

Embodiments are directed to selecting a physical layer for an access terminal's (AT's) participation in a communication session. In an embodiment, the AT can register its priorities for multiple physical-layer systems as well as contact information by which an application server can contact the AT over each system. The AT selectively updates the system prioritization and/or contact information. When the AT joins or initiates a communication session, the application server supports the AT on a highest-priority system through which the AT can be contacted. The system supporting the AT's session can change upon request by the AT, the initiative of the application server and/or a detected triggering event. In a further embodiment, multiple systems can be used concurrently to support the AT's session, such that the AT can send and/or receive signaling and/or media for at least a portion of the communication session over the multiple systems concurrently.

What is claimed is: 
     
         1 . A method of conducting a communication session in a wireless communications system, comprising:
 sending media associated with the communication session to at least one access terminal on a highest-priority system among a previously established system prioritization for a plurality of systems by which the at least one access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   periodically sending a signaling message on the highest-priority system to the at least one access terminal to confirm that the at least one access terminal can still be reached on the highest-priority system; and   selectively updating the system prioritization based at least in part on whether the periodically sending step results in an acknowledgment from the at least one access terminal.   
     
     
         2 . The method of  claim 1 , wherein the selectively updating step includes:
 if the signaling message is not acknowledged by the at least one access terminal, sending a supplemental signaling message on at least one of the plurality of systems other than the highest-priority system; and   if one of the supplemental signaling messages is acknowledged, updating the system prioritization such that the system upon which the acknowledgment is received corresponds to the highest-priority system in the updated system prioritization.   
     
     
         3 . The method of  claim 1 , further comprising:
 receiving a request from the at least one access terminal to transition support of the communication session from the highest-priority system to a different of the plurality of systems;   modifying the sending step such that the modified sending step sends media associated with the communication session to the at least one access terminal on the requested system instead of the highest-priority system.   
     
     
         4 . The method of  claim 3 , wherein the received request either corresponds to (i) a request to temporarily support the communication session on the requested system without modifying the system prioritization, or to (ii) a request to support the communication session on the requested system and to set the requested system as the highest-priority system in an updated system prioritization. 
     
     
         5 . The method of  claim 1 , further comprising:
 determining to send media associated with the communication session to the at least one access terminal on multiple systems among the plurality of systems, such that the media is carried on the highest-priority system and at least one additional system; and   modifying the sending step such that the modified sending step sends media associated with the communication session to the at least one access terminal on the highest-priority system as well as the at least one additional system.   
     
     
         6 . The method of  claim 5 , wherein the determining step determines to send the media on multiple systems in response to a triggering event. 
     
     
         7 . The method of  claim 6 , wherein the triggering event corresponds to (i) the at least one access terminal failing to acknowledge the periodic signaling message and/or (ii) a request received from the at least one access terminal for multiple-system support of the communication session. 
     
     
         8 . The method of  claim 1 , wherein the plurality of systems include one or more of a WiFi system, a CDMA2000 1x system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, a orthogonal frequency division multiplexing (OFDM) system, a long-term evolution (LTE) system and/or a broadcast and multicast service (BCMCS) system. 
     
     
         9 . A method of conducting a communication session in a wireless communications system, comprising:
 receiving media associated with the communication session at an access terminal on a highest-priority system among a previously established system prioritization for a plurality of systems by which the access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   receiving a signaling message on one of the plurality of systems; and   selectively updating the system prioritization based on whether the signaling message is received on the highest-priority system.   
     
     
         10 . The method of  claim 9 , wherein if the signaling message is received on the highest-priority system, the selectively updating step does not update the system prioritization. 
     
     
         11 . The method of  claim 9 , wherein if the signaling message is received on a system other than the highest-priority system, the selectively updating step includes updating the system prioritization such that the system upon which the signaling message is received corresponds to the highest-priority system in the updated system prioritization. 
     
     
         12 . The method of  claim 9 , further comprising:
 sending an acknowledgment to the signaling message on the system upon which the signaling message is received.   
     
     
         13 . The method of  claim 12 , further comprising:
 after the sending step, receiving media associated with the communication session at an access terminal on the system upon which the signaling message is received and the acknowledgment is sent.   
     
     
         14 . The method of  claim 9 , further comprising:
 sending a request to the application server to transition support of the communication session from the highest-priority system to a different of the plurality of systems; and   after the sending step, receiving media associated with the communication session at an access terminal on the requested system.   
     
     
         15 . The method of  claim 14 , wherein the sent request either corresponds to (i) a request to temporarily support the communication session on the requested system without modifying the system prioritization, or to (ii) a request to support the communication session on the requested system and to set the requested system as the highest-priority system in an updated system prioritization. 
     
     
         16 . The method of  claim 9 , further comprising:
 determining that the application server is expected to send media associated with the communication session to the access terminal on multiple systems among the plurality of systems, such that the media is carried on the highest-priority system and at least one additional system; and   receiving media associated with the communication session at the access terminal on the highest-priority system and the at least one additional system.   
     
     
         17 . The method of  claim 16 , wherein the determining step is based on a triggering event. 
     
     
         18 . The method of  claim 17 , wherein the triggering event corresponds to (i) the signaling message being received on a system other than the highest-priority system and/or (ii) a request sent by the access terminal to the application server for multiple-system support of the communication session. 
     
     
         19 . The method of  claim 9 , wherein the plurality of systems include one or more of a WiFi system, a CDMA2000 1x system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, a orthogonal frequency division multiplexing (OFDM) system, a long-term evolution (LTE) system and/or a broadcast and multicast service (BCMCS) system. 
     
     
         20 . An application server, comprising:
 means for sending media associated with a communication session to at least one access terminal on a highest-priority system among a previously established system prioritization for a plurality of systems by which the at least one access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   means for periodically sending a signaling message on the highest-priority system to the at least one access terminal to confirm that the at least one access terminal can still be reached on the highest-priority system; and   means for selectively updating the system prioritization based at least in part on whether the periodically sending step results in an acknowledgment from the at least one access terminal.   
     
     
         21 . An access terminal, comprising:
 means for receiving media associated with a communication session on a highest-priority system among a previously established system prioritization for a plurality of systems by which the access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   means for receiving a signaling message on one of the plurality of systems; and   means for selectively updating the system prioritization based on whether the signaling message is received on the highest-priority system.   
     
     
         22 . An application server, comprising:
 logic configured to send media associated with a communication session to at least one access terminal on a highest-priority system among a previously established system prioritization for a plurality of systems by which the at least one access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   logic configured to periodically send a signaling message on the highest-priority system to the at least one access terminal to confirm that the at least one access terminal can still be reached on the highest-priority system; and   logic configured to selectively update the system prioritization based at least in part on whether the periodically sending step results in an acknowledgment from the at least one access terminal.   
     
     
         23 . An access terminal, comprising:
 logic configured to receive media associated with a communication session on a highest-priority system among a previously established system prioritization for a plurality of systems by which the access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   logic configured to receive a signaling message on one of the plurality of systems; and   logic configured to selectively update the system prioritization based on whether the signaling message is received on the highest-priority system.   
     
     
         24 . A computer-readable storage medium, comprising instructions, which, when executed by an application server, cause the application server to perform operations, the instructions comprising:
 program code to send media associated with a communication session to at least one access terminal on a highest-priority system among a previously established system prioritization for a plurality of systems by which the at least one access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   program code to periodically send a signaling message on the highest-priority system to the at least one access terminal to confirm that the at least one access terminal can still be reached on the highest-priority system; and   program code to selectively update the system prioritization based at least in part on whether the periodically sending step results in an acknowledgment from the at least one access terminal.   
     
     
         25 . A computer-readable storage medium, comprising instructions, which, when executed by an access terminal, cause the access terminal to perform operations, the instructions comprising:
 program code to receive media associated with a communication session on a highest-priority system among a previously established system prioritization for a plurality of systems by which the access terminal can be contacted by an application server, each of the plurality of systems associated with a different physical-layer;   program code to receive a signaling message on one of the plurality of systems; and   program code to selectively update the system prioritization based on whether the signaling message is received on the highest-priority system.