Andy Williamson, Manager, Strategic Core and IMS Marketing, Ericsson
There is currently a fair amount of debate about how best to deliver voice services over Long Term Evolution (LTE) access networks – especially following recent announcements from the VoLGA (Voice over LTE via Generic Access) Forum about its initiatives in this area. But there is already a clear way forward for LTE voice services, based on agreed open standards for delivering real-time services over fixed and mobile all-IP networks.
When LTE radio access networks begin to be commercially rolled out in the next couple of years, we’ll witness a step-change in mobile broadband data speeds. With its ability to deliver 100Mbit/s downloads, LTE will mean improved Internet access for our mobile phones, laptops, dongles and other devices while we’re on the move or away from high-speed fixed line connections. Naturally, we’ll also be able to make and receive telephone calls using LTE-enabled devices.
The problem with the current debate around exactly how LTE voice services should be handled is that it shifts the focus away from the bigger picture. Yes, it is important that traditional voice calls should be handled elegantly and efficiently by LTE devices from the outset. But the LTE-based, all-IP mobile broadband experience will be about much more than this.
An even bigger potential problem with multiple proposals for handling LTE voice is that we could end up with telephony being implemented in inconsistent ways across different networks and different end-user devices – stripping the value away from what is still operators’ biggest and most profitable service.
By putting the right service solutions in place for LTE from day one, operators will have a platform that is not just good for high-speed Internet and basic voice services, but also for converged, real-time multimedia services that really take advantage of the capabilities of LTE and other broadband networks.
Fixed operators leading the charge
Fixed network operators are already having to make crucial strategic decisions about the evolution of their networks over the coming years, as they compete for share of mind – and share of wallet – with alternative media and Internet-based players.
Today, almost all the large fixed line operators focus primarily on modernizing their networks to ensure future competitiveness. This marks a clear shift from the previously common approach of cost-reducing current business by looking for the cheapest way of delivering the widest range of legacy services.
For voice and other real-time communication services delivered over mobile and fixed IP networks, the agreed 3GPP and ETSI/TISPAN standard is Multimedia Telephony (MMTel). MMTel is a service that uses IP Multimedia Subsystem (IMS) architecture to deliver voice and video communications services.
In other words, the MMTel standard is ready to deliver telco-grade voice services over all-IP LTE access networks as soon as they are ready, and to deliver a host of new revenue-generating services into the future. Furthermore, because MMTel sits on standard IMS architecture, it enables network consolidation – reducing overall capital and operating expenditure – as well as fixed–mobile convergence.
Convergence is targeted today through the integration of MMTel into the Rich Communications Suite (RCS) initiative, with specifies a set of common standards applicable to both fixed and mobile networks. It covers the complete range of interoperable communication services, adding – among other things – a presence-powered, active address book, messaging and text chat, and image/file transfer on top of the high-quality voice and video conferencing provided by MMTel.
RCS will ensure that users experience the same look and feel for all communication services, with access to the same address books, buddy lists and message stores, on whatever device they happen to be using, wherever they go. Such capabilities can really only be delivered across fixed and mobile accesses by using standardized IMS architecture and services.
Big-bang, not make-do
Voice services delivered over LTE according to this industry standard will help ensure a ‘big-bang’ introduction of the technology, rather than a ‘make-do’ one. Users will begin to see the benefits of converged multimedia services delivered over LTE very quickly. Operators will be able to evolve and blend services in smart ways – for example, they might enable their subscribers to use an IPTV console to respond to an incoming call in a variety of ways, such as a text message or voicemail, without having to interrupt their viewing.
In the early stages of LTE roll-out, coverage will of course be patchy. Nonetheless, service continuity for telephony based on MMTel will be assured: the 3GPP-standardized Single Radio Voice Call Continuity (SR-VCC) enables in-call hand-over of a VoIP call from LTE to a 3G or 2G cell without interruption.
If mobile operators want to maximize the business opportunity from rolling out LTE, there is really only one path to delivering voice and converged multimedia services – however tempting alternative ‘quick-fix’ solutions may appear.
If you would like to discuss this issue in more detail, please contact: industry.analysts@ericsson.com.
