GSM refarming analysis based on Orthogonal Sub Channel and interference optimization

The current mobile communication environment is advancing rapidly with 3G networks´ data rates growing and LTE representing already the preliminary version of the ITU-R-defined fourth generation. While the 3G and LTE development provides a new era for the multimedia communications with considerably higher bit rates and lower latencies, the legacy systems as 2G are still important as their market share remains high. Regardless of the relatively low spectral efficiency of GSM compared to the new access technologies, both emerging and mature markets benefit from it. 2G still provides with a sufficiently functional platform for the basic voice and data services; moreover, 2G terminal penetration figure remains high, and the radio coverage is typically wider than of more modern networks being deployed in higher frequencies. Furthermore, with the new functionalities of 2G, such as Orthogonal Sub Channel (OSC) and Dynamic Frequency and Channel Allocation (DFCA), the gradual transition towards the new access technologies is granted. This paper investigates the effect of these functionalities on the refarming of GSM frequencies for UMTS/LTE deployment. The study concentrates on urban scenarios and 900 MHz frequency band.