GSM Evolution Importance in Re-Farming 900 MHz Band

Re-farming of 900 MHz band into HSPA has been started and is likely to happen later with LTE. Typically operators have less than 10 MHz block of 900 MHz spectrum and therefore co-existence of two systems in that band is causing challenges. One of the major issues is the high GSM voice traffic that will remain in the GSM network. How to cope the same traffic with significantly less bandwidth for GSM? Orthogonal Sub-Channel (OSC) is a new method to increase voice capacity in the GSM system. OSC intends not only increase the GSM voice capacity but enables very efficient usage of hardware and spectrum resources. In this paper a detailed analysis on OSC performance is made based on system level simulations. Aim is to provide results that show how OSC can be used for refarming of the 900 MHz band into HSPA or LTE. Simulations are carried in the GSM network evaluating capacity for different bandwidths and site configurations. Released frequency spectrum can be used for HSPA or LTE to provide good coverage for rural area mobile broadband. Results show that OSC is an efficient method to release resources for the new systems.