LTE Capacity and Service Continuity in Multi Radio Environment

3GPP standards release 8 and 9 have introduced Long Term Evolution (LTE) Radio Access Technology (RAT) to provide broadband services to end users. LTE is an all-IP packet switched technology. The evolution path towards LTE can be done in two ways. First, for GSM only operators, internetworking between GSM networks and LTE is envisioned to go through IP Multimedia Subsystem (IMS). Second, for 3G/3.5G operators the internetworking can be utilized through Packet Data Network Gateway (P-GW). LTE deployment and internetworking with the existing GSM/EDGE Radio Access Technology (GERAN) and / or UMTS Terrestrial Radio Access Networks (UTRAN) will bring out several technical issues. First, internetworking between GERAN and LTE will highlight the control of voice calls over IP networks. However, most operators agreed to support VoLTE. Second, LTE will be deployed in the same frequency band as of GERAN/UTRAN which will cause signalling problems. In this paper, first, based on service requests, we propose an algorithm to optimize the available network resources in multi radio deployment. Second, single radio IMS enhanced user equipment is modelled, and finally, a voice call continuity study will be conducted through a Discrete Event Simulator (DES) based on multi service environment.