Dialogic Blog

Is Your IMS/VoLTE Future Still Unclear? You Need to Take This First Step Regardless

by Thomas Schroer

Feb 5, 2015 10:28:00 AM


According to the Global mobile Suppliers Association (GSA) more than 80 operators are investing in Voice over LTE networks and 14 of those are currently in production. For operators like SK Telecom, SingTel, T-Mobile US and KDDI and several others, VoLTE is the architecture of choice for delivering advanced IP-based multimedia voice services to their subscribers. It has also been demonstrated that VoLTE provides better voice quality compared to OTT offerings like Skype, faster call set up times, and from an operational perspective, lower cost of ownership compared to traditional circuit switched telephony methods. 

Of course, the IP Multimedia Subsystem (IMS) is at the heart of VoLTE in which three functional platforms – IMS SIP protocol-based core session control, subscriber data repository, and application servers – are used to make an IMS IP call. However, if you want to talk to the majority of the people in the world, there’s one additional IMS platform that is most critical, namely the Media Gateway Control Function or MGCF.

The IMS MGCF is the next evolutionary step for class 4 switching technology, and it’s effectively the PSTN gateway that allows IMS/VoLTE networks to connect with the billions of endpoints not connected by IP.

The research firm TeleGeography tracks the international wholesale voice minutes space and they reported that the share of carrier voice traffic that goes over IP has grown (to 38 percent by the end of 2013), however many of the established service providers still rely on their legacy TDM networks. This means that regardless of whether a service provider deploys VoLTE or an IP next generation network, end-to-end connectivity for the majority of the traffic for many years to come will require IP-to-TDM interworking.

The challenge is that much of the class 4 switching technology still out there is costly legacy TDM, end-of-life, or does not support IMS-to-TDM interworking.  So the critical first step that we’re recommending for an operator is to implement an NGN/IMS surround to their core IP network. This approach positions them to 1) interwork with the multitude of circuit-switched networks using SS7 signaling; 2) lower their ongoing OPEX and CAPEX; 3) reduce the risk of delivering services over unsupported, end-of-life switching infrastructure; and 4) integrate flexibility to deploy an IMS/VoLTE or other IP NGN architecture. The service providers we work with are doing this by replacing their old switching technology to an IMS MGCF-ready NGN class 4 softswitch.

Of all the benefits, flexibility is paramount because IMS may not be in the cards for every operator in every region of the world. Analyst Dean Bubly points out that service providers should at least adopt a strategy that prepares them to find new forms of revenue from multimedia services that are non-IMS based. Implementing an IMS MGCF-ready NGN class 4 softswitch provides operators the ability to take advantage of pretty much any core IP architectural approach that makes the most business sense for them and still pursue an IP transformation makeover.

There’s a short solution brief that we’ve prepared explaining how an MGCF can provide a solid foundation and path to NGN and IMS/VoLTE – check it out and let us know what you think.

Topics: VoLTE/VoWifi & IMS