Analysis on the Scalability Issues of Wireless Mesh Networks: Key Factors and Potential Solutions

Wireless multi-hop networks (mesh) have been proven to be effective in extending network coverage. However, the pioneering research work of Gupta and Kumar [1] has shown that the achievable per-node throughput in a random network is Theta(1 root n log n), which limits its potential for large-scale deployment. A scalable wireless mesh architecture is still not available. In contrast to most work has been concentrated on scaling law derivation, theoretical analysis carried out in this paper reveals that interference and link-sharing are the two key limiting factors of per-node throughput for extended networks. Based on the analysis, a multi-tier hierarchical architecture utilizing 3D beamforming is proposed to overcome the link-sharing problem and achieve scalability in extended networks. MIMO is also considered to be a powerful tool to increase both transmission rate and per-node throughput. Besides, a flexible hybrid architecture that integrates with wired infrastructures is proposed to reduce the difficulty of large-scale deployment of multi-tier mesh networks.