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IPTV/Triple play access networks - Sweet dreams
Both service providers and customers are expecting big things from the next big thing, IPTV/Triple Play. But can the technical requirements fulfil the level of expectations, asks John Mellis
Communications networks are poised to undergo unprecedented, customer-driven transformations. Changes to the backbone networks, in response to burgeoning business and consumer demand for new, faster, richer and cheaper web-based services, as well as the wholesale migration from circuit-switching to IP/MPLS (Internet Protocol/Multi-Protocol Line Switching) packet-based networks are already well underway.
In the access network, the business driver – to deliver profitable new-generation services – is exactly the same, but the practical network issues, and technology solution options, are more complex. Currently prime amongst new-generation services are IPTV and Triple-Play which includes the delivery of interactive video services, over existing telephone lines, to a consumer mass-market. Market-size predictions are still uncertain, but centre around 50 million customers before the end of the decade, from the current base of less than 50,000 IPTV customers globally. What is certain is that the drive to new-generation interactive services will require radical new approaches to managing the urgent transformation and future operation of our communications networks.
The service providers' dream
The overwhelming desire of service providers for attractive new service offerings is well understood, and increasingly obvious to us all. Traditional revenue streams – fixed voice traffic and line rental income – are static or declining under the combined onslaught of lower-cost mobile and IP-based voice services. However, the fixed-line access network, although largely buried, is not dead. Broadband access to the web over xDSL has injected an elixir of youth into the veins of aging copper loops worldwide.
The demand for progressively faster access to an ever-widening range of web services (and media download sources) has proved that last-decade predictions of the demise of the copper local-loops were premature. Reports of the death of the copper loop have been wholly exaggerated. Instead, we see unexpected longevity in the fixed line access network, currently sustained by demand for broadband web access, and for the future, holding the promise of a viable and profitable platform for the delivery of truly wideband and interactive services covering video, voice and Internet data – the service provider's life-line 'Triple-Play'.
Triple-Play offers service providers several promises which are hugely attractive. The opportunity to augment low-margin voice call revenues with new entertainment services, delivered over a common network infrastructure as well as re-invigorated growth to top-line revenues and perhaps higher profit margins. Providing services for the media and entertainment industries offers the chance to leverage a higher percentage of consumers' disposable incomes. With that, the opportunity to shed the staid 'utility industry' image which has subdued the stock price of most telecom operators since the end of the 90's technology 'bubble'. These promises are real, and achievable. However service providers must revolutionise several aspects of their customer access networks to fulfil these promises, and there are many reasons why the expectations of service providers and their customers may be misaligned.
The customers' dream
Customer expectations of next-generation communications services have been shaped by their experiences of the Internet, mobile voice and text services, and the World-Wide Web's ability to search and provide access to large stores of music and image content either free, or at low prices, globally. Most European, North American and East-Asian consumers already have access to many channels of broadcast TV, both analogue and digital, delivered off-air, by satellite, and by cable. Acquiring more channels of generic, broadcast programming is not a high priority for the average customer.
What is attractive are the prospects of real interactivity – true Video-on-Demand, based on rich and accessible stores of content; super-fast web access to knowledge stores; mobile access within and beyond the home, using a variety of wirelessly-tethered devices (lap-tops, PDAs, cameras, phones and music players), with content delivery tailored to the nature of the receiving device. With the proliferation of terminal devices and service offerings, the customer demand for bandwidth is likely to skyrocket.
For those who still doubt the continued buoyancy of future bandwidth demand, consider the following real-world customer scenario. In a domestic household the father is watching a large high-definition television showing a live football match. The transmission is not available on local broadcast TV but is received via his broadband connection using HD-IPTV, consuming an incoming data-rate of 8Mb/s.
At half-time, while watching the football game analysis, he briefly uses his mobile phone to browse the scenes shown by the security video webcams located at his parent's property on the other side of town, since they are away on vacation.
At the same time in the next room, the woman of the house is legally downloading a favourite old movie that she will view after dinner (she is not interested in the football!). The amount of movie data to be downloaded is 5G Bytes at a rate of 40Mb/s – this will take about 15 minutes. While waiting for the download to complete, she is preparing the family meal, and listening on her wireless-enabled MP3 player to some music tracks, previously down-loaded to the household's main hard-disk recorder.
Upstairs, the family's eldest daughter is in a video conference with her Business School associates, who are based overseas. As part of her presentation she enables her personal TV station in multicast mode, so that those involved in the conference can view the digital video she prepared last week. The required outgoing bandwidth to support this activity is 8Mb/s for the video conference plus another 8Mb/s for her up-streaming video document.
The fourth user of the system is the youngest member of this family, a son. He is in another room and has just finished working on a study assignment for school, using the web. Now he is connected to an online 3D gaming and messaging community with 1,000 concurrent users, playing within a realistic virtual adventure world. The symmetric data-rate required for this gaming activity is about 20Mb/s. To support all these activities simultaneously, a symmetric bandwidth of between 50 and 100Mb/s is required, well beyond the capacity of even new-generation xDSL systems.
This kind of scenario illustrates several factors that will be key to future broadband customer satisfaction. Increasing demand for fast, non-real-time downloads of music and movies is extremely important to customers, which means additional bandwidth, beyond the requirements of real-time applications, must be made available. The nature of interactive services is making the usage and traffic patterns symmetric or two-way. The symmetric traffic is generated not only in the external access network as traditionally defined, but also within the customer's home, where many diverse terminal devices are interconnected on the wired and wireless home network.
Lastly, the services that are taken up are highly personalised. In particular, the essence of the attraction to IPTV, VoD and movie downloads is the alternative and archive content available, locally and globally, which differentiates the interactive services from 'vanilla' national broadcast programming.
Fulfilment challenges
Many daunting challenges confront service providers trying to meet customer expectation for new generation interactive services. These most obviously include the acquisition and management of rights to attractive content, and the implementation of new, cohesive billing systems. But perhaps the most fundamental challenge is the least commented upon: the need to raise the quality of aged access networks and systems to deliver the new real-time services, reliably, with high satisfaction levels and adequate profit margins. The problem arises from the legacy of the copper local-loop access network. Historically, the copper access network, required to deliver only basic voice services, received little capital investment in infrastructure and operational management systems. In the early 1990s, the UK copper loop network was regarded as obsolescent and soon to be entirely replaced by optical fibre, with its promise of near-infinite bandwidth capability.
The results of this history of comparative neglect commonly include:
• a mismatch of the availability of spare copper pairs with current geographical demand patterns;
• outdated operational practices (e.g. repetitive pair disconnection and re-connection to cope with customer 'churn)';
• widespread deployments of multiplexers, taps and coils which impede or prevent the delivery of broadband service;
• and poor accuracy in the databases which should record the location and connectivity of access network cables and cross-connection-points.
In some respects many access networks are like a 'ball of wool' – the ends of each circuit are visible and well-located, but the precise internal routings are often a mystery.
This has terrible consequences for the prospects for efficient 21st century service fulfilment and profitable network operations. Frequent engineering field visits to provision, reconfigure or repair the access network, impose a high base of operational costs, eroding service profit margins.
Reliability of future service provision is compromised in several ways:
• predicting the performance and quality of service deliverable over any given customer circuit is problematic, particularly as the penetration of new network services rises to the point where electrical interactions between adjacent circuits and cables is probable;
• maintaining a high quality of service provision (e.g. meeting customer installation dates) is difficult against the background of a poorly-recorded and constantly 'churning' access network infrastructure;
• accurate diagnosis and repair of faults depends on accuracy of access network records for correct interpretation of system test results;
• and finally, poor network data records are a poor basis for strategic network planning. This is crucial, because well-planned strategies will be required to optimise the addition of extra network capacity (e.g. in Fibre-to-the-Kerb deployments) to keep pace with continually increasing consumer bandwidth demands.
The future – breaking the boundaries
In response to these new-service fulfilment challenges, major changes can be expected in the management, and even in the definition, of the future access network. The traditional definition of the network's scope has already expanded, to include broadband local exchange equipment such as DSLAMs (Digital Subscriber Line Access Multiplexer) and, imminently, MSANs (Multi-Service Access Nodes) fed by the fibre-based IP core network. At the customer end, the capability and responsibility of service providers needs to expand beyond the traditional network termination point, into the customer premises network. Customers will expect high Quality of Service to their screens, headphones, hard-disk recorders, and hand-held terminals, not just to the historic network termination point.
Above all, a new mind-set will be required by service providers in managing their external access networks. In the UK, radical restructuring of BT's operations has been agreed with the national regulator (Ofcom) to allow closer focus on access network management, and 'equivalent' treatment of Broadband service retailers. If successful, this model will be replicated more widely. The new interactive services will excite great customer demand (far greater than presently predicted by the conservative market-size estimates of the service providers). But new-generation services will not be the magic bullet for the declining profit margins of traditional communication services. IPTV and VoD provision will require the sharing of customer revenues with content providers and digital rights owners, and the service provider's profit margins may not be as healthy as currently hoped.
Therefore some final mind-set boundaries will need to be breached – namely, the traditional constraints that have hampered capital investment in the access network, to the detriment of operational efficiency and the broadband 'delivery potential' of the infrastructure. This trend will certainly be corrected and reversed, so that stabilised, lean-operation access networks, based on hybrid copper-fibre-wireless infrastructures, will be the basic platforms for new-generation service delivery – just in time for the next revolution, the long-awaited high-volume rollout of optical fibre-to-the-home, which will be required to satisfy the newly-stimulated demand for the 100Mb/s symmetric services of the next decade. •
John Mellis is CTO, Evolved Networks, and can be contacted via tel: +44 (0)1473 663 027; e-mail: john.mellis@evolvednetworks.com www.evolvednetworks.com
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