User Equipment Context Transfer Over Radio Access Network Paging

Abstract

This document describes methods and systems for user equipment (UE) context transfer over radio access network (RAN) paging. A first base station receives from a second base station a first message that includes a context that is associated with a user equipment while the user equipment was in an engaged mode with the second base station. The first base station transmits a second message that is a paging message to the user equipment and in response receives, from the user equipment, a third message that includes a resume message authentication code identifier. After the first base station verifies the third message using the resume message authentication code identifier, the first base station transmits, to the user equipment, a fourth message that enables the user equipment to resume the engaged mode with the first base station in accordance with the context.

1 - 15 . (canceled) 
     
     
         16 . A method performed by a first of two base stations comprising:
 receiving, by the first base station and from a second base station, a first message that includes a context of a user equipment that was previously in an engaged mode with the second base station;   transmitting, by the first base station in response to receiving the first message and to the user equipment, a second message that includes a radio network temporary identifier that identifies the context;   receiving, by the first base station from the user equipment, a third message that includes a resume message authentication code identifier;   verifying, by the first base station, the third message by comparing the resume message authentication code identifier received in the third message with a calculated message authentication code identifier; and   transmitting, to the user equipment, a fourth message that enables the user equipment to resume the engaged mode with the first base station in accordance with the context.   
     
     
         17 . The method as recited in  claim 16  wherein:
 receiving the first message includes receiving a set of parameters that comprise one or more of a physical cell identifier, a cell radio network temporary identifier, a resume constant, or a key; and 
 verifying the third message includes verifying that the resume message authentication code identifier is identical to a calculated message authentication code identifier generated by the first base station based on the set of parameters. 
 
     
     
         18 . The method as recited in  claim 16  wherein:
 receiving the first message includes receiving a calculated message authentication code identifier generated by the second base station; and 
 verifying the third message includes verifying that the resume message authentication code identifier is identical to the calculated message authentication code identifier. 
 
     
     
         19 . The method as recited in  claim 16 , wherein:
 receiving the first message includes receiving a plurality of calculated message authentication code identifiers, each calculated authentication code identifier of the plurality of calculated message authentication code identifiers generated by the second base station; and   verifying the third message includes verifying that the resume authentication code identifier is identical to a calculated message authentication code identifier from the plurality of calculated message authentication code identifiers.   
     
     
         20 . The method as recited in  claim 16 , further comprising transmitting, by the first base station to the second base station, a fifth message that indicates forwarding address information. 
     
     
         21 . The method as recited in  claim 20 , further comprising:
 transmitting, by the first base station and to a core network, a sixth message that indicates a request to perform a path switch; and   receiving, from the core network, a seventh message that includes a response to the sixth message.   
     
     
         22 . The method as recited in  claim 21 , further comprising transmitting, by the first base station and to the second base station, an eighth message that includes a context release command, the context release command effectuating a release of resources supporting wireless communications between the second base station and the user equipment. 
     
     
         23 . The method as recited in  claim 16 , wherein the second message is a radio access network paging message. 
     
     
         24 . The method as recited in  claim 16 , wherein the third message is a radio resource control paging message. 
     
     
         25 . A method performed by a user equipment, the method comprising:
 discontinuing, by the user equipment, an engaged mode with a second base station to enter a disengaged mode;   receiving, from a first base station, a first message that includes a radio network temporary identifier that identifies a context associated with the user equipment while the user equipment was in the engaged mode with the second base station;   converting, by the user equipment, the radio network temporary identifier to a resume message authentication code identifier;   transmitting, by the user equipment to the first base station in response to receiving the first message, a second message that includes the resume message authentication code identifier; and   receiving, by the user equipment from the first base station, a third message from the first base station, wherein the third message causes the user equipment to:
 resume, with the first base station, the engaged mode in accordance with the context; or 
 remain in the disengaged mode. 
   
     
     
         26 . The method as recited in  claim 25 , wherein, prior to discontinuing the engaged mode, the user equipment receives, from the second base station, a radio resource control release message that includes a suspend configuration. 
     
     
         27 . The method as recited in  claim 25 , wherein discontinuing the engaged mode causes the user equipment to enter a radio resource control inactive state. 
     
     
         28 . The method as recited in  claim 25 , wherein the second base station is a last-serving base station. 
     
     
         29 . The method as recited in  claim 25 , wherein receiving the first message includes receiving a radio resource control paging message. 
     
     
         30 . A first base station comprising:
 a wireless transceiver; and   a processor and computer-readable storage media comprising instructions to implement a context manager application, the context manager application configured to direct the first base station to:
 receive, from a second base station, a first message that includes a context of a user equipment that was previously in an engaged mode with the second base station; 
 transmit, in response to receiving the first message and to the user equipment, a second message that includes a radio network temporary identifier that identifies the context; 
 receive, from the user equipment, a third message that includes a resume message authentication code identifier; 
 verify the third message by comparing the resume message authentication code identifier received in the third message with a calculated message authentication code identifier; and 
 transmit, to the user equipment, a fourth message that enables the user equipment to resume the engaged mode with the first base station in accordance with the context. 
   
     
     
         31 . The first base station of  claim 30 , wherein the context manager application is further configured to direct the first base station to transmit, to the second base station, a fifth message that indicates forwarding address information. 
     
     
         32 . The first base station of  claim 31 , wherein the context manager application is further configured to direct the first base station to:
 transmit, to a core network, a sixth message that indicates a request to perform a path switch; and   receive, from the core network, a seventh message that includes a response to the sixth message.   
     
     
         33 . The first base station of  claim 32 , wherein the context manager application is further configured to direct the first base station to transmit, to the second base station, an eighth message that includes a context release command, the context release command effectuating a release of resources supporting wireless communications between the second base station and the user equipment. 
     
     
         34 . The first base station of  claim 30 , wherein the second message is a radio access network paging message. 
     
     
         35 . The first base station of  claim 30 , wherein the third message is a radio resource control paging message.