Although LTE adoption has taken off in almost every market, with some moving rapidly towards LTE-Advanced, implementing Voice over LTE (VoLTE) is progressing more slowly. This may be due to the need to move to the IP Multimedia Subsystem (IMS) core, a relatively costly, if strategic, investment. Nevertheless, most observers believe it will prevail, so service providers need to start considering now the opportunities and challenges around innovative new ways to monetise VoLTE, says Jonah Pransky of Amdocs
First of all we need to determine, in charging terms, what is VoLTE? Is it voice or is it data?
If it is voice, then CSPs should be rating based on duration and location, and a VoLTE call should either be charged accordingly or deducted from the voice allowance of a subscriber’s plan. If it is data, then a VoLTE call should be rated based on volume, and the subscriber should either pay a per megabyte fee or have the volume deducted from their data allowance.
But why should CSPs limit themselves to simple pricing plans for VoLTE services? Perhaps they want to create a complex rating logic, one that allows them to create more innovative rate plans and offers. For instance, service providers could offer higher quality VoLTE calls for business purposes, as opposed to personal use. We can even consider a rating logic that combines various dimensions of the VoLTE call and create attractive new offers, such as zero-rating data – the volume – for calls made from within the subscribers’ home zone – the location.
Taking this one step further, the promise of VoLTE and IMS lies in the ability to mash up combinations of high quality rich communication services (RCS) – voice, video, instant messaging (IM) location and sharing. CSPs should be able to charge for these carrier-grade services, based on the richness of the service given its better quality than free over-the-top (OTT) services, as well as the duration or volume of the service.
So there are many options for VoLTE monetisation; as either voice, data or high quality value-added services. The decision on how any particular CSP decides to monetise their VoLTE service may be driven more by market forces than industry best practice, but it must never be a decision based on technology limitations, and an inability of the CSP’s rating and charging system to handle all options.
With all of these opportunities, what’s the challenge?
As always, the challenge comes when we move from the theoretical into real-word situations. For instance, until LTE network coverage is 100%, CSPs will be handling calls that are handed off between different generation networks. A person starting a VoLTE call who moves into an area with no 4G reception must be handed over to a 3G or 2G network in order to avoid disconnects. Assuming that is done successfully, the signal for the call will be coming from different network sources generating different events.
Monetising RCS-type (rich communication suite) services adds another layer of complexity. As the different services are sourced over different network paths and components that do not necessarily integrate one with the other, we need to be able torate a charge accurately for a single servicegenerating session from multiple sources. This is further complicated by the fact that the different event reporting sources for these different aspects of the service are volatile, delivering events at different times and with different notions of what a session is, making it imperative that the correlation of all of these different sessions into one usage record, and their subsequent processing, rating and charging, is done in real-time.
Other challenges in rolling out VoLTE include interoperability between different VoLTE service providers, but these are problems for CSPs to decide between themselves and industry bodies. AT&T and Verizon, for example, have announced that subscribers on their respective networks will be able to make VoLTE calls between the two networks. The key challenge of monetising VoLTE however, is in having the technology in place to support new and attractive pricing models for services that differentiate service provider offerings from their OTT counterparts. And that challenge must be solved by each service provider having the charging capabilities to effectively address signal and session correlation.
So what is required?
Given the complexity of charging for VoLTE services, there are a couple of clear requirements for effective VoLTE monetisation. Firstly, the charging system must be tightly integrated with the disparate network subsystems that send signals based on rich VoLTE communications services; such as MMTel for video (Diameter Ro), P-Gateway for location-based services (Diameter Gy) and PCRF (Policy and Charging Rules Function) for QoS (Diameter Sy/Rx). It must then be able to correlate all of the signals coming from the use of a VoLTE service by a single subscriber into one session, which is rated according to a rating logic that correlates all of the information from the various network sources into a unified event and charges the subscriber accordingly for a single service. It must ultimately do all of this in real-time in order to ensure that subscribers are given exactly the right access to the services volumes and quality levels they have purchased at any given time.
Real-time charging is the crucial foundation
Many challenges lie ahead for CSPs in order to ensure they can provide the quality of experience that consumers expect from, as well as achieve a profitable return on their investment in, LTE, IMA and VoLTE. A modern, real-time convergent charging solution is crucial to achieving this goal. With the significant explosion in VoLTE still to come, service providers need to act now to ensure they have the right systems in place to support offers that really stand out from the competition. To do that, they can’t just rate, they have to correlate.
