Comparing Unlicensed Mobile Access (UMA) and Voice Call Continuity (VCC) Architectures

As the concept of fixed-mobile convergence (FMC) is gaining popularity among operators and consumers, there is an increasing debate about the performance of the mobile-network-centric UMA architecture versus the IP-centric VCC architecture. While UMA-based FMC solutions are already launched for commercial use, VCC-based solutions are still in their trial stages. The purpose of this paper is to compare the performance of the two architectures based on the call handover (HO) delay and throughput, in order to answer the following question: is preferring UMA over VCC a business decision or a technical performance decision? We found that the two architectures do not significantly differ from one another in throughput when subject to different traffic and delay profiles. Moreover, the literature shows that, similar to UMA, VCC is capable of handling data-session continuity between different network domains. Thus, the choice between UMA and VCC is governed by non-technical factors such as network upgrade cost for different operator profiles. The mobile-network centric UMA is better suited for mobile operators whereas the IP-centric VCC is suited for mobile virtual network operators (MVNOs) that do not own a licensed spectrum or a mobile core network.