In a survey with global service providers that have deployed IMS core equipment in their networks or will do so by the end of 2018, IHS firm found that the deployment of IP multimedia subsystem(IMS) in the Network Function Virtualization(NFV) enviroment is expected to grow to 78 percent by 2018, driven by the ability to scale services up and down quickly and also the operational efficiencies it is expected to deliver. This scores a significant increase from the current 17% deployment of IMS on NFV infrastructure.
Operators worldwide continue to deploy and expand IMS networks for a variety of services, but mobile has become king and VoLTE is driving the majority of new activity. As the largest driver for IMS, VoLTE is dictating the challenges and product requirements. The study found that 91 percent of carriers surveyed plan to run voice over LTE (VoLTE) services over IMS in the next two years.
According to IHS, the biggest challenges to IMS are migrating legacy subscribers and justifying capital expenditures on a new network for a service (voice) that represents declining revenue. Although IMS is still viewed as complex, requiring significant system integration and vendor interaction, it exposes larger challenges as operators look to move all their subscribers to IP.
Fixed-line voice over IP (VoIP) service continues to be the mainstay of IMS deployments. The transition from fixed-line VoIP to mobile services over IMS is happening, but in a measured fashion, found the market firm. Today, 57 to 65 percent of operators surveyed run residential voice over broadband, Session Initiation Protocol (SIP) trunking or hosted business VoIP over IMS, growing to 87 to 91 percent by 2018.