The profitable generation of new service revenues is a key priority for mobile operators. Yet
introducing new services, and blends of services, can look a daunting and expensive technical challenge, with the requirement for new call and session control technologies.
Mobile Europe caught up with Seamus Hourihan, Vice President, Marketing & Product Management, Acme Packet (right), to hear how mobile operators are implementing Session Initiation Protocol (SIP) in their networks to enable them to create and manage new services.
Mobile Europe:
Seamus, with operators challenged to create profitable new revenue sources as well as drive down operating costs, many are of the view that technologies like SIP will be crucial in enabling operators to manage these services more effectively.
How are your operator customers viewing the implementation of SIP within their networks?
Seamus Hourihan:
When it comes to the current implementation of SIP, there are three areas of growth: in the core, on the interconnect between borders, and on the subscriber access side of the service infrastructure.
Many service providers have implemented IP cores to link disparate parts of their networks together. Yet, signaling has largely remained legacy (i.e., circuit-switched), which stops short of the full potential cost savings.SIP in the core
In the core, SIP activity is being driven chiefly by the operators’ need to reduce capex and opex. Many service providers have implemented IP cores to link disparate parts of their networks together. Yet, signaling has largely remained legacy (i.e., circuit-switched), which stops short of the full potential cost savings. Employing SIP-based elements means they can benefit from centralised routing databases, instead of having one at each MSC, resulting in complex and costly route management. This sort of development is occurring initially in the USA, and we expect to see more movement elsewhere around the world as operators face the same challenges that US operators have done as they move to all-IP networks.
More efficient interconnect
On the interconnect side, things are happening simultaneously with the movement of SIP to the core. As service providers move from TDM interconnectivity to IP, using session border control solutions, such as we provide, means they can reduce their interconnect costs by up to 50%. Interconnect set-up times are reduced from weeks to days, and there is also the added advantage of an increase in the quality of the voice calls they support, as the need for transcoding different voice codecs is eliminated.
One of the factors driving this move is that in the USA there’s a trend to move to a “bill-and-keep” business model. A bill-and-keep business model eliminates all the cost and hassle of the administrative infrastructure associated with per call settlement or negotiated settlements on termination costs. Again, it’s occurring in the USA primarily as the rest of the world is still wedded to the GSMA business model of negotiated settlements, as reflected in the GSMA’s IPX initiatives.One issue associated with the movement to SIP is, “How to do it?” IMS is an architecture – a functional architecture that does not tell you how to combine functions together. That’s challenging for operators to figure out because each vendor has its own solution.
SIP for Rich Communications Suite and Fixed-Mobile Covergence
The third area, that I termed SIP for enabling enhanced subscriber access, is being driven by the GSMA’s Rich Communications Suite (RCS) initiative – with the use of SIP to complement circuit-switched voice in 3G networks. RCS allows operators to augment and enhance the address book and messaging services, to create connected services of greater value to the user. This side of things is moving a little slower, in terms of looking at the number of subscriber calls handled by SIP, but we see great potential. In European markets, there is considerable activity on RCS in Southern Europe and in France in terms of trials, and these trials continue to go well.
Fixed-mobile convergence is another service which enhances subscriber access by bridging mobile services from the 3G RAN to femotocell and WiFi access points. The goals of this service are to increase geographic service coverage for subscribers and off-load the macro 3G RAN to reduce costs.
Mobile Europe:
One challenge operators face is how to get the benefits of implementing SIP-enabled elements through the network without committing to a full, transformative, all-IP network architecture at the same time.
Seamus Hourihan:
Yes, one issue associated with the movement to SIP is, “How to do it?” IMS is an architecture – a functional architecture that does not tell you how to combine functions together. That’s challenging for operators to figure out because each vendor has its own solution.
Acme Packet is a proponent of IMS and, in fact, our products fulfill many critical functional elements, such as the Proxy-CSCF. However, we also realize that IMS represents a complex and resource intensive migration.This is why Acme Packet has recently introduced products that have IMS-like functions, and standard interfaces, but that can enable operators to emulate IMS elements in a very cost-effective manner. Our SIP Multimedia-xpress (SMX) uses industry standard interfaces to add IMS functionality to our session border controller solutions, allowing operators to offload core SIP routing to centralised elements, instead of interconnecting a host of points of presence.
That creates a very affordable solution, just $2-3 per subscriber for 100k subscribers. And used with the session-aware load balancing solution that we announced at Mobile World Congress, operators can create clusters to manage the distribution of up to two million subscribers on the access side. This means that service providers can start small and then scale this to a full IMS solution in a very cost effective way using products from Acme Packet and our IMS core vendor partners
Mobile Europe:
And operators can have confidence that they will still have full interoperability in an IMS environment?
Seamus Hourihan:
IMS defines standard interfaces between functions, like between the serving CSCF and application server. As long as there is a standard interface to these elements, then these standard interfaces go a long way to ensuring interoperability, even though the elements themselves may still run into issues in how developers interpret those standards.I feel that we are just wasting our precious time and money if our only goal with LTE is to deliver circuit-switched voice calls over LTE.
Mobile Europe:
Another high-profile role for SIP recently has been in the development of the One Voice, now the GSMA-backed VoLTE, initiative to find a common method to deliver IMS voice over LTE networks.
Seamus Hourihan:
Yes, and we’ve been a very active proponent of SIP for delivering voice services and more interactive services over LTE. I feel that we are just wasting our precious time and money if our only goal with LTE is to deliver circuit-switched voice calls over LTE. The goal is really to enable the new services we don’t have yet. We are fully supportive of VoLTE, and the vision it has of providing a single SIP-based IMS standard for providing voice over LTE.
But I would like to add that SIP, whether as part of a full IMS architecture or not, enables everything that everyone talks about from the over-the-top providers, as well as more efficient and higher quality voice. It enables the blending of new services and user experiences that will allow operators to compete in the new environment.