Power-efficient routing mechanism for ODMA systems

Opportunity driven multiple access (ODMA), a cellular multihop method proposed for Universal Mobile Telecommunications Systems, potentially allows reduction in power consumption of user equipment (UE), extending Node B's coverage and supporting higher user data rate. However, ODMA requires extra power for discovering relaying nodes and introduces additional transmission latency in data transfer. This paper offers enlightenment to these ODMA implementation problems. A power-efficient routing (PER) mechanism is proposed to identify a minimum-power path for ODMA communication. Prior to the route (or path) discovery, the PER mechanism utilizes an analytical solution to estimate the total power and number of intermediate UEs required in the minimum-power path. With the estimation, route discovery procedures originating from nonattainable ODMA requests can be prevented. For those attainable ODMA requests that require a route discovery procedure to locate intermediate UEs, the PER mechanism further provides a method to set the transmission power and maximum hop count. Hence, the power consumption of each UE during route discovery is significantly reduced. Simulation results coincided with the analysis, and the results demonstrate the performance improvement of PER over dynamic source routing.