Condensed Downlink MAP Structures for IEEE 802.16e Wireless Metropolitan Area Networks (MANs)

Abstract

The new mobile wireless metropolitan area network (WMAN) architecture imposes a demanding performance requirement on the radio resource to provide broadband internet access. The radio resource is partitioned as bursts in time and frequency domains and used by mobile stations (MS) in an exclusive manner. The base station (BS) functionally serves as a resource controller for traffic to and from the MSs associated with it, and thus naturally generates the proper downlink (DL) and uplink (UL) MAPs for active MSs based on service and traffic requirements. However, the DL-MAP construction scheme in IEEE 802.16e OFDMA standard, which was designed for handling irregular traffic pattern of MS, often produces a large DL-MAP, as a certain small amount of data distribution to MSs will render a potential overhead of information elements (IE) in DL-MAP and limit the overall capacity. Moreover, the robustness requirement on MAP broadcasting would further cause severe system overhead. As a solution, we propose two exclusive condensed DL-MAP structures, which only carry partial information of each rectangular burst in order to reduce the size of IE in DL-MAP. For each condensed DL-MAP structure, the algorithms for BS to produce the condensed DL-MAP structure and the scheme for MS to precisely reconstruct the original DL-MAP structure are provided. As confirmed by the analytical results, the proposed condensed DL-MAP can achieve significant DL-MAP size reduction compared with standard DL-MAP structure.