VillageNet: A low-cost, 802.11-based mesh network for rural regions

Abstract

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 gateway IEEE 802.11 equipment and optimizing the network topology to directional nodes minimize cost. In this paper we describe the over-all operation links of VillageNet and discuss two fundamental problems in building such a network.Nodes in VillageNet communicate using long-distance pointto-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 villages (nodes) 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 A. Architecture at nodes. The cost of a tower depends on its height, which in turn A typical rural mesh network is depicted in Figure 1. It depends on the length of its links, and the physical obstructions along those links. Thus to minimize cost, we pose the problem of ould cn is toof c tof villages connected wilth each deciding which links should be established, such that all villages other through point-to-point wireless links. Some special nodes are connected and the cost of constructing antenna towers to in this mesh, called gateway nodes, will be connected to the establish the selected links is minimized. wired internet. Other mesh nodes will connect to the gateway node (and thus, to the rest of the internet) through one or more

Minimum Cost Topology Construction for Rural Wireless Mesh Networks

“…It follows from STAR-TC-ALGO that J is a subset of the list L at the beginning of the for loop in line 12. 8 Also, for any node u ∈ J, incr opt (u) is equal to the h + (u) selected in the algorithm. Now consider a height increment incr algo where the first |J| elements of L have height increment given by h + , v has increment δ, and all other nodes have increment 0.…”

“…16 WiMAX have prohibitively expensive equipment costs. As a result, there has been considerable recent interest [2], [8], [16], [17] in the design of rural mesh networks using IEEE 802.11 (WiFi) equipment. The cost of an 802.11 radio (∼$50/PCMCIA card) is orders of magnitude less than that of cellular/WiMAX base stations.…”

“…There has been some recent work on constructing low-cost wireless mesh networks [19], [8]. The authors in [19] discuss solutions to the topology construction problem in the same context as ours−rural mesh networks where the costs are dominated by the height of antenna towers.…”

“…The authors in [8] also discuss a geometric version of our problem but do not provide any algorithm for solving it. So, to the best of our knowledge, we present the first algorithms for solving the topology construction problem with provable guarantees on the approximation factor.…”

TDMA MAC Protocols for WiFi-based Long Distance Networks: A Survey

“…Several research test beds have also been set up in recent times. MIT's Roofnet [4], QuRiNet [24] at the Quail Ridge Reserve in Napa County, California, FRACTEL [5] at IIT Bombay, India, and VillageNet [7] are some of the important WiLD network research test beds which are working towards network performance enhancement, providing support for various envisaged applications particularly real-time applications such as e-learning, e-governance, telemedicine, and telephony.…”