System and method for voice service in an evolved packet system

Abstract

A system and method for enabling voice services using a network component in a communication system including a user equipment (UE) is provided. The UE is configured to receive a first message which may be a SIP request. The network component is configured to create a second message, or SIP request, based upon the first message. The network component further configured to subsequently receive a SIP response and select a subsequent action upon receiving the SIP response.

1 - 20 . (canceled) 
     
     
         21 . A method, comprising:
 transmitting, from a network node to a user equipment (UE), an initial Session Initiation Protocol (SIP) Invite request, wherein the initial SIP invite request includes a session description protocol (SDP) offer that allows the UE to select, between an internet protocol (IP) bearer or a circuit-switched (CS) bearer;   in response to the initial SIP Invite request, receiving, at the network node and from the UE, a SIP response comprising an indication that the initial SIP Invite request is not acceptable, wherein the UE determines that the initial SIP Invite request is not acceptable based on at least one of the following scenarios:
 a voice setting in the UE is “CS only” and the UE has not performed a successful non-access stratum (NAS) combined attach procedure, wherein the successful NAS combined attach procedure attaches the UE to both a packet-switched (PS) core and to a circuit-switched (CS) domain; or 
 the voice setting in the UE is “CS preferred” and the UE has not performed the successful combined attach procedure and an IP Multimedia Subsystem (IMS) over PS session is not supported. 
   
     
     
         22 . The method of  claim 21 , wherein the SDP offer allows the UE to select the IP bearer or the CS bearer for an audio session. 
     
     
         23 . The method of  claim 21 , wherein the SIP response comprises a SIP 606 (Not Acceptable) response. 
     
     
         24 . The method of  claim 21 , wherein the SIP response comprises a SIP 488 response. 
     
     
         25 . A network node, comprising:
 a memory; and   at least one processor comprising processing hardware platform, wherein the processing hardware platform is configured to execute instructions stored in the memory, the instructions causing the network node to:   transmit, to a user equipment (UE), an initial Session Initiation Protocol (SIP) Invite request, wherein the initial SIP invite request includes a session description protocol (SDP) offer that allows the UE to select, between an internet protocol (IP) bearer or a circuit-switched (CS) bearer;   in response to the initial SIP Invite request, receive, from the UE, a SIP response comprising an indication that the initial SIP Invite request is not acceptable, wherein the UE determines that the initial SIP Invite request is not acceptable based on at least one of the following scenarios:
 a voice setting in the UE is “CS only” and the UE has not performed a successful non-access stratum (NAS) combined attach procedure, wherein the successful NAS combined attach procedure attaches the UE to both a packet-switched (PS) core and to a circuit-switched (CS) domain; or 
 the voice setting in the UE is “CS preferred” and the UE has not performed the successful combined attach procedure and an IP Multimedia Subsystem (IMS) over PS session is not supported. 
   
     
     
         26 . The network node of  claim 25 , wherein the SDP offer allows the UE to select the IP bearer or the CS bearer for an audio session. 
     
     
         27 . The network node of  claim 25 , wherein the SIP response comprises a SIP 606 (Not Acceptable) response. 
     
     
         28 . The network node of  claim 25 , wherein the SIP response comprises a SIP 488 response. 
     
     
         29 . A non-transitory computer-readable medium storing computer instructions, that when executed by one or more hardware processors, cause a computing device to perform operations comprising:
 transmitting, from a network node to a user equipment (UE), an initial Session Initiation Protocol (SIP) Invite request, wherein the initial SIP invite request includes a session description protocol (SDP) offer that allows the UE to select, between an internet protocol (IP) bearer or a circuit-switched (CS) bearer;   in response to the initial SIP Invite request, receiving, at the network node and from the UE, a SIP response comprising an indication that the initial SIP Invite request is not acceptable, wherein the UE determines that the initial SIP Invite request is not acceptable based on at least one of the following scenarios:
 a voice setting in the UE is “CS only” and the UE has not performed a successful non-access stratum (NAS) combined attach procedure, wherein the successful NAS combined attach procedure attaches the UE to both a packet-switched (PS) core and to a circuit-switched (CS) domain; or 
 the voice setting in the UE is “CS preferred” and the UE has not performed the successful combined attach procedure and an IP Multimedia Subsystem (IMS) over PS session is not supported. 
   
     
     
         30 . The non-transitory computer-readable medium of  claim 29 , wherein the SDP offer allows the UE to select the IP bearer or the CS bearer for an audio session. 
     
     
         31 . The non-transitory computer-readable medium of  claim 29 , wherein the SIP response comprises a SIP 606 (Not Acceptable) response. 
     
     
         32 . The non-transitory computer-readable medium of  claim 29 , wherein the SIP response comprises a SIP 488 response.