Voice over LTE

Abstract

Long Term Evolution (LTE) is the latest high speed mobile broadband technology that is gaining widespread attention due to its high data rates and improved Quality of Service (QoS). Initially, LTE was seen as a technology for supporting high speed data, but there is a growing interest in the industry to support voice over LTE. The support of voice over LTE has lot of challenges owing to the fact that both voice and data traffic are to be carried over the same radio and core networks. The optimum usage of resources in the radio network is of high importance as there is a growing need to improve the capacity at reduced cost. The transport network is another key area that needs to be carefully planned according to the capacity of the radio network. Differentiation and scheduling of resources in the transport network plays a key role in guaranteeing good end to end performance for both voice and data services. In this thesis, the impact of differentiation and scheduling of resources in the transport network on the end to end performance of voice over LTE is investigated. The results indicate that without proper prioritization and scheduling of resources in the transport network, the performance of voice is severely affected when the transport network is congested with data traffic. To overcome this scenario, we prioritize voice over data traffic and analyse its performance for different transport network scheduling algorithms. From the results, it is clear that with proper classification and scheduling of resources in the transport network, significant increase in voice capacity is observed. On the other hand, by totally prioritizing voice, performance of the data traffic is affected to a large extent. Hence, to achieve a balance, voice users are classified into different priority levels and the performance of voice and data in this scenario is investigated. The analysis for all these scenarios are based on simulations using OPNET simulation tool.