  The density of mobile phones has increased rapidly in recent years. One
drawback of the current mobile telephone technology is that it forces all the
calls to go through cellular base stations even if the caller and the callee
are within the radio range of each other. Hybrid cellular networks and
Unlicensed Mobile Access (UMA) have been proposed as solutions that enable
mobile phone users to bypass cellular base stations. However, these
technologies either require special hardware or in some cases have to rely on
the service providers. We identified that most of the Commodity-off-the-Shelf
mobile phones are Wi-Fi (and Bluetooth) enabled. We propose a Community Mobile
Network (COMONet) which utilizes Wi-Fi (and Bluetooth) to build ad hoc network
among mobile phone users to bypass GSM base stations whenever possible. COMONet
does not depend on special noncommodity hardware and it is a software based
solution. COMONet monitors all the available paths over the ad hoc network and
it transparently switches to the regular path over the service provider's GSM
base station if a path is not available over the ad hoc network. In COMONet the
caller and the callee do not have to be within the Wi-Fi or Bluetooth range of
each other to make a call since the COMONet is capable of routing calls through
the other mobile nodes that are participating in the COMONet.
