Providing mobile phone access in rural areas via heterogeneous meshed wireless back-haul networks
Wireless Mesh Networks (WMNs) are often seen as an affordable solution to bring Internet connectivity into rural and previously unconnected regions. To date, the main focus has been to provide access to classical services such as the WWW or email which requires the users to use a personal computer or a recent smart phone. In many developing regions, however, the prevailing end user device is a mobile phone. In order to connect mobile phones to an IP-based wireless back-haul networks, the network access points must provide a mobile phone air interface, compatible with GSM or UMTS specifications. Avoiding dependence on a costly mobile operator infrastructure, we propose to deploy GSM or 3GPP nano cells in order to terminate the mobile phone protocols immediately at the local network access points. Therefore, voice or data traffic can be carried over wireless back-haul networks using open protocols such as SIP and RTP. In this paper we present a meshed wireless back-haul n etwork architecture whose access points have been equipped with GSM nano-cells. The voice packets generated by mobile phones are carried across the back-haul network in parallel to typical web or video traffic. We evaluate the QoS handling received by the voice calls across our multi-hop wireless testbed and show that our architecture can provide the resource isolation required to offer uninterrupted VoIP services in parallel to regular Internet traffic.