On BS/BS coordination towards interference minimization in WiMAX networks

Broadband wireless networking is a rapidly evolving research field supported by both industrial and academic communities. Focusing on the Medium Access Control (MAC) layer, IEEE 802.16 protocol family constitutes a prominent technology offering significant advantages in terms of meeting the continuously increasing application demands. However, cross-interference due to co-channel Base Station (BS) transmission residing in adjacent cells constitutes a challenging issue preventing optimum resource utilization in an IEEE 802.16 system thus significantly degrading network performance. In this paper a study on this problem is presented, based on a well-known system level network simulator. Furthermore, driven by valuable conclusions extracted by the aforementioned evaluation, an Internet Protocol (IP) layer coordination mechanism is presented, implemented and evaluated in the context of the network simulation environment, indicating significant behavioral and performance improvement. An important aspect of this work is to focus on critical concerns for industry, such as, the implementation feasibility and efficiency, while preserving backwards compatibility to existing systems. The main objective of the coordination mechanism is to achieve optimum bandwidth allocation in overlapping coverage areas, compensate from degraded throughput performance, and minimize side-effects due to coordination overhead.