With a number of spectrum reframing (e.g. 900 MHz spectrum re-farming) being done to free up band for LTE technology use, operators may have to reduce their GSM capacity and may share their GSM networks. As re-farming significantly reduces the set of frequencies allocated to GSM, 3GPP decided to look in to the RAN sharing method and along with supporting companies found that MOCN (Multiple-Operator Core Network) is optimal RAN Sharing method.
The transmission path is an important part of wireless networks. In wide rural areas or in remote areas, operators sometimes face the challenges to deploy networks due to the lack of or cost of fast and reliable backhaul transport network. Statistical data indicate that many calls in a mobile network in these areas are local calls. There is good probability that call between two terminals go via same BTS or in between co-located BTSs or with in same BSC.
3GPP initiated, IMS Centralized Services (ICS) paves the way for communication services that are based on IMS mechanisms. ICS enables IMS services for traditional circuit switched voice access. With ICS, user sessions are anchored in IMS network when user devices access via PS or CS access networks. UEs can be enhanced to support ICS capability otherwise UEs without ICS capability are also supported by ICS framework.