Standard based solutions for voice and SMS services over LTE

LTE (Long Term Evolution) is the last step towards the 4th generation (4G) of radio technologies, therefore seen as a high priority for the operators in the deployment of future telephony networks. Most of today's operator revenues come from Voice and SMS services, making Voice and SMS over LTE the first services to be offered to customers in the 4G networks. This paper discusses different technologies for Voice over LTE, comparing the requirements and benefits for the operator as well as for the end-user. Both the solutions based on open standards (3GPP, TISPAN) and non-standardized solutions are discussed, although the priority is given to the standards-based solutions.