— In this paper, the system capacity of a multi-cell IEEE 802.16j system operating in transparent mode is investigated. A previous published analytical model is used and incorporates interference from neighbouring cells. The model can be used to determine downlink performance under max-min fairness constraints for both sectored and omnidirectional systems with different amounts of relays. The study provides guidelines on the design of 802.16j systems operating in transparent mode – specifically, how to maximise throughput for such systems. It is shown that inter-cell interference from relays is limited in a suburban environment and that relays can deliver significant gains over single hop systems: gains of 30% and 60% can be achieved without and with spatial reuse in an omnidirectional system while 15% and 25% in a sectorised system.