Abstract – UTRA-FDD requirements for operation in the 900 MHz band have been recently standardized in 3GPP paving the way for refarming of GSM spectrum to UMTS. UMTS900 networks will have to co-exist with GSM900 networks for some time. 3GPP  has studied co-existence issues and has concluded that GSM900 and UMTS900 can co-exist in both coordinated and un-coordinated deployments in which the UMTS900 carrier is allocated 5 MHz in addition to a guard-band ...
Vieri Vanghi, Mustafa Saglam, and Jiang Jindi
July 18, 2013
Frequency Coordination Between UMTS and GSM Systems 900 MHz