Beyond 3G Cellular Multi-hop Networks

Beyond third-generation mobile communications networks will comprise a multitude of integrated legacy and new wireless networks. Mobile ad hoc networks are such new networks. In this paper, we consider the integration of the universal mobile telecommunications system (UMTS) that is a third-generation legacy mobile network and mobile ad hoc networks that are built using the IEEE 802.11 technology. Since UMTS and IEEE 802.11-based ad hoc networks have different but complementary features, the integration would leverage the advantages of each other. We have investigated the performance of real-time traffic over such an integrated network. The considered UMTS radio channel bit rates were ranging from 64 kb/s to 2 Mb/s with varying channel block error rates. Simulation results show that higher UMTS channel bit rates incur the lower end-to-end packet delay. In addition, the end-to-end delay incurred by the 802.11-based multi-hop ad hoc network is small as compared with the UMTS channel for low application traffic load. However, for large application traffic load, the performance bottleneck is shifted to the 802.11-based multi-hop ad hoc network.