On-demand session establishment for All IP-based mobile networks

Increasing demand for mobile data communications and for various applications encourages mobile network operators (MNOs) to deploy new radio access technologies (RATs). The third generation partner project (3GPP) has specified an all-IP-based mobile core network: evolved packet core (EPC) which can can accommodate a 3.9-G RAT (Long Term Evolution [LTE]) as well as conventional RATs, such as UMTS and CDMA2000. The cellular RATs can release radio resources (assignment of the radio frequency and the transmission time slot) when a mobile terminal (MT) is in an idle mode. However, the EPC nodes, such as anchor and mobile access gateways, maintain all these MT sessions. This means that MNOs are forced to retain the sufficient capacity in the gateways despite the fact that active MTs are much less than the total subscribing MTs. This paper proposes modifications to the service request procedure which establishes the communication path when an MT in the idle mode begins communications. The modification enables the EPC nodes to maintain the sessions only for MTs in an active mode where the MT has on-going communications. and to release the context (session-related information) for MTs in the idle mode. A simulation-based evaluation shows that the proposal can reduce the sessions maintained by MNOs to one fourth of the total MTs.