Michael D. Turner

System aspects and handover management for IEEE 802.16e

The IEEE 802.16 family of standards that are currently being developed target wide area, cellular, high data rate transmission for non-line-of-sight terminals. The initial phase of the standard (802.16d) supports fixed terminal locations and the subsequent phase of the standard (802.16e) provides support for mobile terminals. The standards specify physical layer (PHY) and media access control (MAC) layer functionalities with several flexible options for frequency reuse and handover. We describe various system architectures for handling handovers in an 802.16e system based on the capabilities of the current draft standard (802.16e D8). The system architecture description combines the functionalities provided in the standard at the PHY and MAC layers with network layer signaling to provide a complete solution. Specifically, we propose hard handover with MAC context reset for a low mobility scenario and a layered migration procedure using fast base station switching (FBSS) with MAC context transfer for a high-mobility scenario and Internet Protocol (IP) packet forwarding for seamless mobility. Our handover solution is applicable to both flat and centralized network architectures. We discuss evolution paths through these various options, keeping in mind that the initial deployments are likely to be for limited mobility and low capacity, while future deployments will target high mobility and increased capacity.