Comparing frequency planning against 1×3 and 1×1 re-use in real frequency hopping networks

On the one hand, the potential of radio link control options like frequency hopping, power control and discontinuous transmission for capacity increase in GSM mobile radio networks has been extensively studied by several authors using computer simulations in homogeneous hexagonal networks. Unfortunately, some idealistic assumptions on these network models have a substantial drawback on the practical relevance of the simulation results. On the other hand, many field trials and regular network operation have proven very good results in terms of both network quality and capacity when applying radio link options in tight frequency re-use. But there, systematic investigations are hardly feasible. Therefore, we present results of close-to-reality simulations of FH networks showing that FH, PC and DTX can largely improve system capacity in real non-homogeneous networks by as much as 200%. We systematically investigate both advanced frequency assignments at varying re-use and frequency assignments in cluster 1×3 and 1×1. Our results reveal some aspects contrasting widely spread views on implementing FH in real networks. From our investigations we deduct recommendations concerning the optimum approach of using frequency hopping, power control and discontinuous transmission in GSM networks