Billing in an all converging IP-world

Internet protocol (IP) is truly revolutionising the communication technologies available to people in their day-to-day lives. With IP, and more importantly IMS and its various flavours, a standard is finally emerging that is not tied to the access-means and transport.

What this creates is a framework for seamless interactivity across any number of networks, wireline or wireless alike and devices, such as PCs and mobile phones, to name just two. There are many angles to IP and the way it impacts billing, but we will focus specifically on the following three:

Billing for broadband and the impact of residential multi-play
Most operators today have solved their initial broadband billing needs. After all, it is in many ways one of the simplest charging-scenarios – a monthly fee for access and nothing else. However, when moving towards triple and quad-play this is not so straightforward. Even though subscription to a TV-package may just be another recurring monthly fee, many of the value propositions that IPTV offers over traditional TV requires a lot more flexibility.

Therefore, when assessing billing solutions for broadband, the impact of additional content, TV and VoIP, for example, shouldn’t be underestimated. The major trend points are towards solutions that are capable of both managing cyclic billing (such as producing invoices, accounting properly for recurring charges and the capability to pro-rate) with online balance management such as for content, video-on-demand and other services.

For example, with IPTV, service providers will enable users to pay and view a premium sports event when visiting a friend who has a different set-top box. This capability requires solutions that span orders, billing and customer-care rather than having separate CRM, ordering and billing systems. The key advantage of the tight link between ordering and charging is that the CSR has full visibility of what is happening. If a customer has signed up to a football final that has just started but that he can’t view, he can call the call-centre to ask why its not available and the CSR will have the full picture. If not, the customer-experience can easily be so disastrous that the customer decides to churn.

IMS and its impact on billing
With IMS comes a number of opportunities and challenges in the billing-space. One fundamental shift between traditional networks and IMS is that in traditional networks signalling to control calls was costly. Often in fixed networks there would be no single point for the control of calls, and in a mobile network so-called SS7 signalling was required. The signalling is used to authorise the session before and during the session when it is used.

As signalling in an IMS world travels over the IP network, such constraints are not necessarily relevant any longer and IMS represents an opportunity for operators to move towards ‘now-authorised’ charging. In other words, instead of charging happening at some point later based on a CDR, the call is validated, rated and charged for immediately. If one is to implement such features, a convergent solution with proven scale in the network is required.

Another challenge that IMS brings is the multiple opportunities to charge for a session. If it is a download, perhaps the so-called ‘bearer-channel’ or transport is charged for. However, if one is watching a video over the same network, there may be a one-off charge for the film instead, which includes the streaming (‘bearer’ again) of the film. In such scenarios, real-time correlation and aggregation will become important features, either in the charging or between the network and charging as ‘active mediation’ in order to make the correct charging decisions from different information off the network.

Another aspect that needs to be considered is the variety of services that are offered. As these increase, cost-efficient means for signing up and managing these services will be required. Today, operators have systems, often based around CRM to manage all ordering through a call-centre. With more services on offer, self-service and the use of the internet will become increasingly more important. Finally, it will be important to have systems that can provide consistent ordering and billing behaviour, regardless of the channel being used. A customer may use a website, a store or a gaming device to activate the same service. If this is supported with separate systems all requiring their own integration and management, the agility and cost-efficiency will quickly be lost.

VoIP and other IP-based services
Another area of rapid development is the rolling out of IP-based voice or voice over IP (VoIP). For VoIP services, charging has been relatively unimportant as most VoIP today travels over internet and therefore rarely carries any charges. There is the exception when the VoIP call interconnects to a PSTN, in which case interconnection charges exist. However, this has been relatively easy to solve by measuring the calls at the interconnection point between VoIP and the PSTN, either at the switch or gateway.

However, as VoIP matures and in particular if other IP-based services start appearing, such as video-calling, a wish to charge for the sessions may emerge, as they carry a cost in terms of volume of data being transported across the network. As many of the VoIP and IMS technologies are potentially peer-to-peer and therefore are routed directly to the two parties, once the connection is established, it becomes quite hard to control the session. In particular, once it is established there is nothing to stop it if a customer has run out of balance.

Because of this, a couple of new technologies are being developed. The standards assume that applications running on top of IMS will have interfaces to the charging through Diameter and associated protocols such as Parlay/X. However, in many cases the current application servers – for example, an IP-based switch – do not have such interfaces. In these cases, technologies such as a ‘SIP-Proxy’ have been explored. When using a SIP-proxy, it acts as the destination for the calling party and then calls the ‘true’ destination on behalf of the caller. This way, the SIP proxy can request a disconnection of both the origin and destination party, should there be no further credit. In the medium term, various applications are likely to be implemented using SIP-proxy technology.

In an all IP world, services are converging and access and transport should become less significant over time. When looking at the billing needs for an all IP world it is an interesting lesson to look at the internet today. Internet customers expect continuous access to their billing information. One example is eBay – as soon as a user decides to sell something, he or she is guided through the selection of options for which the price is immediately available, even if it is a promotion or a discount based on his or her profile. Moreover, as soon as something is purchased, the charges and the balance are available immediately. Since the website is the livelihood of the business it needs to always be there. At the same time, because of the reach of the internet, one system can support over 50 million sellers across the globe with minimal operational cost.

If one compares such streamlined operations with today’s telco providers there is a wide range of billing services, which can be developed to match the service capabilities of the internet. As telcos enter this new bright era of IPTV, content and IMS-based services, they may perhaps re-consider their back-office infrastructure and invest in solutions that enable the wide variety of IP services that the new converged world has to offer.