Channelization for dynamic multi-frequency, multi-hop wireless cellular networks

Multi-hop relaying in cellular networks can greatly increase capacity and performance by exploiting the best available links to a base station. We envision an environment in which relay networks are dynamically formed when performance on the radio access network is degraded and then dissolved when the performance improves or the radio spectrum on which the relay network is operating is reclaimed. Each relay network operates on a different frequency band. Likewise, a relay network may channelize its frequency band to offer non-interfering links among the mobile nodes within a single relay network. We propose a set of algorithms used to form such relay networks on-demand. Each algorithm provides a simple and distributed frequency assignment scheme. We also propose two enhancements to improve network throughput of resulting relay networks. We evaluate these algorithms in terms of the overhead of the relay network formation. The evaluation results show that having nodes outmost from the BS initiate route discovery first is the best approach for reducing the formation overhead. The results also show that there is a large increase in throughput when using multiple frequencies in a relay network. Further, the performance of the network using multiple frequencies based on our simple frequency assignment is very close to that of a network using optimal frequency assignment.