Abstract
In this paper we analyse the performance of a relay based UMTS system in an urban environment using multiple hops on multiple frequency bands. Measurement based path loss, fading and shadowing models are used in the Manhattan grid deployment scenario. Both uplink and downlink operations of the cellular system are considered at the same time. Two hop communication links over the uplink and downlink are operated at four non-overlapping spectrum bands in order to minimise interference. This results in several possible frequency schemes. Power solutions are derived analytically for the selected frequency schemes. The system performance is evaluated both by simulation and analysis and improvement by employing relays is shown.