Designing ad hoc networks with limited infrastructure support

Ad hoc networks based on IEEE 802.11 (Wi-Fi) wireless links are viable for small regions with a few tens of mobile nodes, but such networks suffer from frequently broken routes and low network utilization. We investigate the benefits of adding a few infrastructure nodes to an otherwise ad hoc network to improve its performance. These infrastructure nodes are interconnected among themselves with point-to-point (p2p) links in addition to Wi-Fi capability. To evaluate the benefit of ad hoc networks with mixed broadcast wireless and point to point links, we modify an existing ad hoc routing protocol to automatically discover routes emphasizing p2p links and simulated several ad hoc and mixed networks using the Glomosim simulator. Our results show that adding a small number of point-to-point links makes a significant difference in performance with 2-3 times higher throughput and up to 2-3 times lower packet delays.