Wimax standards and Security The Wimax

RNG-RSP
(Location update response, paging group ID)


New location info of MS
(MS new location)

FIGURE 6.12
Location update procedure.



FIGURE 6.13
Procedure of network reentry from idle mode.

paging group ID of the target BS. In addition, the paging controller can send a backbone message to the BS at which the MS entered idle mode, to give notice that the MS has transferred to a different paging group.

3. Network Reentry from Idle Mode

An MS in idle mode reenters the network when it wants to connect to its network to receive/transmit data. Figure 6.13 shows the procedure of network reentry from idle mode. The MS initiates network reentry with the target BS

by sending an RNG-REQ message, which includes the ranging purpose indi- cation of network reentry request and the paging controller ID. If the target BS receives an RNG-REQ that includes a network reentry indication and it had not previously received information about the MS over the backbone, the target BS requests information about the MS from the paging controller over the backbone network, and the paging controller responds. Network reentry procedures can be shortened if the target BS possesses information about the MS. If the target BS possesses such information, it sends the MS an RNG-RSP with an HO process optimization TLV that indicates which reentry manage- ment messages can be omitted. Then, the MS and BS communicate with each other to perform the network reentry procedure with respect to such mat- ters as the negotiation of SS basic capability, authentication, and registration. After the network reentry process is completed, normal operation is resumed. The target BS notifies the paging controller of the successful network reentry of the MS via the backbone, and the paging controller can also send a back- bone message to the BS at which the MS entered into idle mode, to give notice that the MS has resumed normal operation at the new BS.

5.