 in order to listen for broadcast control messages for communication supervision (primarily acknowledgment messages and resource reassignments). It is allocated by a bitmap, which indicates the specific blocks dedicated to the mobile station on each assigned time slot of the TDMA. The bitmap is determined by the PCU (traffic management Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Radio and MS-PCUSN Interfaces Radio and MS-PCUSN Interfaces functionality) and avoids collisions (simultaneous access of several mobile stations on the same PDCH block). A bitmap is always determined inside the PCU, whatever the communication mode, but it is transmitted to the mobile station in the case of static UL allocation only. In this case, the mobile station decodes the bitmap as rectangular (as many fields as TS allocated). In the previous list and in Figure 6-15. two mobile stations have been allocated time slot 2 on a same TDMA, but collisions will be avoided thanks to the bitmap, which allocates different blocks to the mobile stations on time slot 2. Temporary Block Flow Continuing with the previous example, the focus remains only on time slot 2 (UL and DL), allocated to both mobile stations (mobile station 1 and mobile station 2), which is shown in Figure 6-16. On the downlink, only mobile station 1 continuously (all blocks) monitors time slot 2 because this time slot has been allocated to mobile station 1 as the DL CONTROL time slot in the Packet Figure 6-15 Static uplink TS 1, 2, 3 allocation. DL_CONTROL_TS=TS 2 TBF_STARTING_TIME(MS1). ALLOCATION BITMAP Packet Resource Assignment TS 2, 4, 5 0L_CONTROL_TS=TS5 TBF_STARTING_TIME (MS 2 2) ALLOCATIONS BITMAP What happens on TS 2? Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject