Interference Analysis on UMTS-2100 Co-Existence with GSM-1900

A possible mobile spectrum allocation for mobile operators that offer 2G/3G services is WCDMA 2100MHz system co-existing with a GSM 1900MHz system in the same coverage area. In this scenario inter-band interference exists at mobile subscriber (MS)/user equipment (UE) level and network/base transceiver station (BTS/Node B) level, and the objective of this paper is to observe this behavior. For that purpose, measurements were taken in a laboratory configuration where variables were adjusted in order to explore main RF environment characteristics in real life such as: the received signal level at GSM phone, the distance between WCDMA/GSM phones, the guard band between systems and the transmission output power of UEs. The results show that the interference levels can decrease the quality and the capacity of networks using this spectrum allocation.