Most of the service providers pursuing quality have spent many years honing their ability to deliver and manage voice services to the point where reliability is almost perfect — we need five-nines just to remind us that it's not absolutely perfect. Even their experience with data services, despite early bandwidth limitations, has consistently improved.

If there is one arena that poses a threat to their records of reliability, it's the realm of IP-based services. Voice over IP's (VoIP) quality is much improved over the years when telcos wouldn't touch it, but ask any business using VoIP if it's the same quality as their old TDM service — maybe they know what the acronyms mean, but most of them know the difference, however slight, in quality. IPTV represents a new world of service management to the telephone companies that are investing in it.

The former Bell companies are in the early deployment stages of their IPTV projects, and many independent telcos already are launching IPTV services. For all of them, IPTV is a new adventure. The challenges of managing the new services has influenced these service providers and their vendors to think about service quality in a new way.

In a network environment in which traditional voice services are the primary offering, benchmarks for what constitutes a quality voice connection are obvious and easy to monitor in a centralized fashion. With IPTV, service quality is more subjective, more relevant to the experience of individual users and the increasing number of ways in which they interact, compared with their fairly one-dimensional relationship with traditional voice services.

This has inspired vendors helping IPTV service providers to manage their services to devise ways to describe the new thinking about IPTV quality. Spirent Communications says it's all about “subscriber experience management.”

“Subscriber experience management is not necessarily something new, but the service providers and manufacturers building these networks now understand that managing the subscriber experience is the key to the next generation of services,” said Anders Gustafsson, CEO of Spirent. “Service providers are always focused on signing up the new customers, but keeping those subscribers is a higher priority today than it has ever been.”

Although focusing more on the user experience doesn't sound like a new or imaginative idea, measuring that experience and translating it into something that carriers and vendors can manage and influence is something else.

Measuring subscriber experience requires companies to get much closer to their customers and to somehow look at a particular service from an individual customer's point of view, but without disrupting the service or that customer's use of it.

SwissQual, a test developer based in Switzerland, invented what it describes as Non-Intrusive Network Assessment (NINA) to help network operators and their vendors follow a program of subscriber experience management. NINA uses algorithms — in the case of IPTV, a special video algorithm — to disassemble signals and examine their core reference points and potential degradation factors. These elements have values attached to them and then are recombined and mapped to a Mean Opinion Score (MOS). The MOS gives IPTV managers a metric for subscriber experience management that can be further evaluated for potential improvement.

SwissQual's work in subscriber experience management is part of what influenced Spirent to acquire the company last year, Gustafsson said. “Its findings about how to score subscriber experience are part of the advantage to us owning the company,” he said. “No one else is really competing on that basis right now, though that doesn't mean no one will.”

Though SwissQual had been fond of licensing its algorithms to other vendors manufacturing their own test systems, Gustafsson said, “We're not licensing it for now. We're looking for more ways to use it internally.”

Spirent isn't the only vendor that understands the new test requirements for IPTV. And it's not the only company using new phrases to describe those requirements. Robert Winters, co-founder and CEO of Ireland's Shenick Network Systems (named for an island off the Irish coast near Dublin), said, “Previously, when you were talking about testing a broadband service, you were talking about throughput. Now, you might say what you're looking for is ‘good-put.’ [That is] how many good, stateful packets can you run through the network,” he said. “It's not how many megabits per second you can provide, but how many connections per second you can support at a high level of quality.”

Shenick has worked mostly in European IPTV deployments so far, supporting vendors that are involved in the initial construction of these networks. “Telcos are really just starting with IP,” Winters said. “The thing they want to know most right now is what's going to happen when they add another thousand subscribers to their IP networks?”

He added that most service providers are well aware of what's at stake as they offer new kinds of IP-based services. There has been a great deal of excitement over services like IPTV, but the transition to offer IPTV ubiquitously may be a gradual and step-wise migration — much like it was with VoIP.

“There's a lot of work that goes into this before the service even launches,” Winters said. “Service providers need to look at every single element in this IPTV architecture. A lot of people are very conscious that they will only get one shot at getting this service right.”

Because they have existing relationships with cable TV companies — which initially weren't known for the quality of their customer service records, but have improved in recent years — customers signing up for IPTV may have “zero tolerance” for poor service quality. This is in part because they already expect the best from their telephone companies. But Winters said video quality isn't the only factor in providing a quality IPTV service.

Service providers must also be conscious of several factors, including the speed at which their systems allow customers to change channels; of the performance of their remote control devices; and of the response and activation times of their ordering and billing interfaces for on-demand programming.

“It's not just video quality,” Winters said. “Channel ‘zap-rate’ is a big deal.”

The IPTV market opportunity is inspiring the industry to develop new ways of thinking about and of measuring service quality. It's also inspiring some aggressive — and acquisitive — strategic thinking in the traditionally reserved world of test and measurement systems.

In addition to SwissQual, Spirent has made three acquisitions in the last several months, sold a non-test division and restructured its organization — all in the name of better addressing a growing market for testing IP-based wireline and wireless networks and services.

JDS Uniphase, which owns Acterna, recently bought another test firm focused on IP monitoring. Also, Agilent is emerging from a long restructuring process during which it shed non-test assets. Meanwhile, Shenick, which has been around for six years, is attempting to expand globally and to work more closely with service providers.

The IPTV trend may still be in its earliest stages, but these vendors are charging ahead as if the market were a sure thing. But Spirent's Gustafsson said there is good reason for that. “Will IPTV be successful? With the amount of money that the industry is investing in its development, it's almost inconceivable that it won't.”