METHODS AND APPARATUS FOR MOBILITY IN MOVING NETWORKS
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.