Design of High Throughput Scheduled Mesh Networks: A Case for Directional Antennas

Scheduled wireless mesh networks (WMNs) represent an important paradigm in the development of high speed wireless access networks. As a consequence of (Aditya Karnik, 2006), it can be shown that the maximum throughput of a single gateway n node WMN is upper-bounded by 1/n, normalized with respect to the highest available data-rate. The situation is actually worse since with conventional omni-directional antennas, the achievable throughput is considerably lower at low powers. This paper makes a case for smart (directional) antennas. For the same power, smart antennas can provide higher range, and therefore shorter paths, as compared to omni-directional antennas. For the same range, smart antennas can operate at lower powers, reducing the interference, and thereby improving the spatial reuse. Although they cannot change the fundamental throughput limit of 1/n, smart antennas can achieve significantly higher throughput at lower powers, These insights are demonstrated through several numerical examples using the framework of (Aditya Karnik, 2006).