Methods and apparatus for mobility in moving networks

Abstract

A method and apparatus for receiving a broadcast configuration indicating when a change in a RAN function termination occurs is provided, for example, by a timer value. The broadcast configuration may be received from a satellite, blimp or other moving transmitter. A dedicated configuration may also be received from the serving cell. The dedicated configuration may include a preamble, a transient configuration and an indication of a layer 2 behavior. If a WTRU detects a change in RAN function termination, the WTRU may suspend any uplink data transmissions, apply the transient configuration and transmit the preamble to a target cell. The WTRU may synchronize with the target cell and apply the layer 2 behavior.

1 . A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
 receiving information from a serving cell, wherein the information indicates when a change in a radio access network (RAN) function termination occurs;   receiving a preamble from the serving cell; and   when the change in RAN function termination occurs,
 transmitting the preamble to a target cell, wherein the target cell is different than the serving cell. 
   
     
     
         2 . The method of  claim 1 , further comprising:
 synchronizing with the target cell, wherein a layer 2 (L2) behavior associated with the serving cell is preserved following the synchronization with the target cell.   
     
     
         3 . (canceled) 
     
     
         4 . The method of  claim 1 , further comprising: receiving a security configuration from the serving cell, wherein the security configuration is applicable to the target cell. 
     
     
         5 . The method of  claim 1 , wherein the information includes one or more of: a timer value indicative of when the change in the RAN function termination occurs; proximity information indicative of when the change in the RAN function termination occurs and/or location information indicative of when the change in the RAN function termination occurs. 
     
     
         6 . The method of  claim 5 , further comprising:
 decrementing the timer value to determine when the change in the RAN function termination occurs.   
     
     
         7 . The method of  claim 1 , wherein the serving cell is provided by a satellite. 
     
     
         8 . The method of  claim 1 , wherein the serving cell is provided by a blimp. 
     
     
         9 . A wireless transmit/receive unit (WTRU) comprising:
 a receiver configured to receive, information from a serving cell, wherein the information indicates when a change in a radio access network (RAN) function termination occurs;   the receiver further configured to receive, from the serving cell, a preamble; and   circuitry configured to, when the change in RAN function termination occurs,
 instruct a transmitter to transmit the preamble to a target cell, wherein the target cell is different than the serving cell. 
   
     
     
         10 . The WTRU of  claim 9 , further comprising:
 the receiver further configured to receive an indication of a layer 2 (L2) behavior from the serving cell, wherein the circuitry is configured to apply the L2 behavior and is further configured to re-establish one or more radio bearers of the serving cell on the target cell.   
     
     
         11 . The WTRU of  claim 9 , further comprising:
 the receiver further configured to receive a RACH configuration from the serving cell, wherein the RACH configuration identifies first RACH occasions;   the receiver further configured to receive a transient configuration from the serving cell, wherein the transient configuration identifies second RACH occasions;   wherein a total number of the second RACH occasions is greater than a total number of the first RACH occasions.   
     
     
         12 . The WTRU of  claim 9 , further comprising:
 the receiver further configured to receive, from the serving cell, a security configuration for use with the target cell.   
     
     
         13 . The WTRU of  claim 9 , wherein the information includes a timer value indicative of when the change in the RAN function termination occurs. 
     
     
         14 . The WTRU of  claim 13 , further comprising:
 circuitry configured to decrement the timer value to determine when the change in the RAN function termination occurs.   
     
     
         15 . The WTRU of  claim 9 , wherein the target cell is provided by a satellite. 
     
     
         16 . The WTRU of  claim 9 , wherein the target cell is provided by a blimp. 
     
     
         17 . A satellite comprising:
 a transmitter configured to transmit information which indicates when a change in a radio access network (RAN) function termination occurs; and   the transmitter further configured to transmit a preamble for use with a target cell of another satellite.   
     
     
         18 . The satellite of  claim 17 , further comprising:
 the transmitter further configured to transmit information indicative of a transient configuration, wherein the transient configuration indicates opportunities for downlink (DL) synchronization measurements.   
     
     
         19 . The satellite of  claim 18 , wherein the transient configuration indicates opportunities for UL synchronization. 
     
     
         20 . The satellite of  claim 18 , wherein the transient configuration indicates a start of an UL resource availability for a preamble transmission. 
     
     
         21 . The satellite of  claim 17 , wherein the information includes one or more of: a timer value indicative of when the change in the RAN function termination occurs; proximity information indicative of when the change in the RAN function termination occurs and/or location information indicative of when the change in the RAN function termination occurs.