Unified Architecture for Ad-hoc and Cellular Networks

In third-generation (3G) wireless data networks, providing service to low data-rate users is required for maintaining fairness, but at the cost of reducing the cell?s aggregate throughput. We have proposed the Unified Cellular and Ad Hoc Network (UCAN) architecture [20, 21] for enhancing cell throughput while maintaining fairness. In UCAN, a mobile client has both 3G interface and IEEE 802.11-based peer-to-peer links. The 3G base station forwards packets for destination clients with poor channel quality to proxy clients with better channel quality. The proxy clients then use an ad hoc network composed of other mobile clients and IEEE 802.11 wireless links to forward the packets to the appropriate destinations, thereby improving cell throughput. We have refined the 3G base station scheduling algorithm so that the throughput gains are distributed in proportion to users? average channel rates, thereby maintaining fairness. With the UCAN architecture in place, we have proposed novel greedy and on-demand protocols for proxy discovery and ad hoc routing that explicitly leverage the existence of the 3G infrastructure to reduce complexity and improve reliability. We have also proposed secure crediting mechanisms to motivate users that are not actively receiving to participate in relaying packets for others. Through both analysis and extensive simulations with HDR and IEEE 802.11b, we have shown that the UCAN architecture can increase individual user's throughput by more than 100 percent and the aggregate throughput of the HDR downlink by up to 50 percent.

Most Relevant Papers