Improving capacity in a GSM system with DCS1800 and dual band mobiles

The capacity of a GSM system can be improved in several ways. This paper focuses on a GSM system complemented with DCS1800. The capacity of a combined GSM and DCS1800 system with GSM mobiles and dual band mobiles has been simulated. Two types of dual band mobiles have been studied. They are both able to set up a call in either system. But only one of them can also change system at handover. The conclusion of the paper is that the dual band mobiles that cannot change between GSM and DCS1800 during a call are not suitable when the coverage differs between the two systems. The dual band full system handover improves the capacity approximately nine times, under Swedish conditions, when each GSM cell are complemented with an equal sized DCS1800 cell.