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VillageNet is a wireless mesh network that aims to provide low-cost broadband Internet access for rural regions. The cost of building the network is kept low by using off-the-shelf IEEE 802.11 equipment and optimizing the network topology to minimize cost. In this paper we describe the over-all operation of VillageNet and discuss two fundamental problems in building such a network. Nodes in VillageNet communicate using long-distance point-to-point wireless links that are established using high-gain directional antenna. VillageNet uses the 2P MAC protocol [?], that is suited for the interference pattern within such a network. However, the 2P protocol requires the underlying mesh graph (for each 802.11 channel) to be bi-partite. Thus, if K channels are available, then an important consideration is how to select K bi-partite subgraphs to activate, such that the demands of the nodes are best met. We formally pose this problem and present some initial results. Second, we observe that the dominant cost of constructing such a mesh network is the cost of constructing antenna towers at nodes. The cost of a tower depends on its height, which in turn depends on the length of its links, and the physical obstructions along those links. Thus to minimize cost, we pose the problem of deciding which links should be established, such that all villages are connected and the cost of constructing antenna towers to establish the selected links is minimized. |
