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INTRODUCTION
Over the last few years, video over broadband in its various forms has been associated with the hype around convergence. Content digitization, new broadband technologies, and the promise of ubiquitous broadband access triggered high expectations in the media and telecommunications industries. In spite of numerous lab and field trials (in Europe almost every telecom operator tested video over broadband) and impressive media-industry consolidations, there have been no commercial launches of video over broadband services until very recently. Several factors can explain the gap between market expectations and the first deployment of video services, from business and legal challenges to technical challenges.
Technology has been evolving since 1995. Set-top boxes and other video building blocks have started following a "Moore-like" law in terms of cost versus capacity driven by digitization and increasing use of IP and Ethernet. Interoperability between the video building blocks has also accelerated over recent years, resulting in more attractive return-on-investment (ROI) models. The media industry is now seriously considering broadband as another distribution channel. And with recent deployments of Ethernet- and IP-based technologies on the access and aggregation side, together with cost-effective Optical transport, service providers are now seriously reconsidering the viability of video over broadband.
The most successful providers of triple play and video over IP have built their networks with Cisco® products. Over 10 million subscribers around the world are using IP and Ethernet networks from Cisco to deliver video-including video service market leaders like Comcast, Fastweb, Hong Kong Broadband, Neuf Telecom, and Surewest. The Cisco portfolio of products and services ranges from core switching, routing and optical transport to aggregation routers, access and home residential gateways. Combined with application-layer services, policy and control, Cisco can provide the right IP video architecture needed to meet and exceed today's and tomorrow's video service goals.
Cisco has unparalleled network linkages to the video application. Cisco designed and built much of the Gigabit Ethernet-based IP video transport now used in both cable and telco copper and fiber networks. Using our expertise, Cisco has deployed numerous innovations that link the video application to the network and offer the flexibility and intelligence to adapt to ongoing changes, and continues to develop more to meet the demands of an evolving, successful video service. These range from asymmetric networking and failure-recovery scenarios to an intelligent video control plane for admission control and dynamic resource sharing. Video applications-especially a complex mix of broadcast and video on-demand (VoD), as well as the emergence of high-definition-drive the need for large amounts of asymmetrical bandwidth and increase the need for intelligent video service admission control and video component resource management.
Cisco's leadership and innovations translate into lower operational barriers and raise the performance of the entire IP video and triple play system. Our solutions are designed to help service providers overcome the main challenge: taking video services to the next scale, from hundreds of thousands of subscribers to millions, in the most cost-effective way.
BROADBAND AS ANOTHER VIDEO DISTRIBUTION CHANNEL
The residential broadband market has changed beyond recognition since the introduction of ADSL Internet access in the late 1990s. With the accelerating commoditization of broadband through increased DSL penetration rates in the majority of European countries, telecom operators are struggling to reinvent themselves, to create market differentiation through innovation, and to find new ways of extracting value from their DSL infrastructure. In order to maintain profitability, many operators are moving from offering Internet access over DSL to delivering value-added services over DSL. Triple play services, which bundle voice, video, and data services over broadband, are being deployed as operators face the challenge of maintaining profitability and reducing customer churn in a commoditized market. In addition to communication and information services such as voice and data, many service providers are now looking to expand their share in the entertainment market as a way of increasing their penetration and maintaining average revenue per user (ARPU), and in turn profitability. In the face of fierce competition in Europe, the number of operators offering video over DSL services in its various forms (such as TV broadcast and on-demand services), is likely to increase over the next few quarters, either in a cooperation or "co-opetition" with content owners and media companies. The first deployments will probably be TV over DSL, where network operators will partner with a TV broadcaster. But in the longer term, operators will move into co-opetition mode and start adding their own content to existing services.
By 2008, market analysts predict 8 to 10 million subscribers in Europe for video-related services over broadband, compared to less than 1 million subscribers in 2004. This represents approximately 10% to 15% market penetration in terms of European broadband connections. North American and Asian service providers are also planning video over broadband deployments.
In order to achieve video services delivery that can scale up to these market projections, Cisco has been working on key component-providing rich interworking functionality between the video application and the network. You can think of this as a video application layer sitting over the underlying network layer, which provides network services rather than just connectivity to the upper video layer.
By working closely with the leading video vendors and the standards bodies (such as IETF, DVB forum, ISMA) in the definition of this interworking layer model, Cisco has been able to apply its powerful IP toolkit (QoS, security, multicasting, scalability) to the video distribution process from the very earliest stages of technology development.
Time to market and time to service are major concerns of service providers worldwide. This means that Cisco's extensive industry knowledge in video transport, coupled with a solid track record of successful service provider deployments of triple play services over broadband, delivers a value proposition that is unparalleled in the industry.
NETWORK CHALLENGES
Broadband and convergence have caused traditional cable and satellite media providers to turn their focus to alternative access methods such as DSL and Ethernet. Competition has been fierce, and in countries like France, alternate service providers are taking a significant share of the broadband market away from the incumbent-a situation hardly imaginable a few years ago.
Competition has energized the market, with some providers taking very creative and innovative approaches. In order to be successful, reducing time to market is crucial. This can be achieved by using homogeneous, end-to-end solutions that have been proven in real deployments.
From a technology standpoint, it is crucial that the new broadband solutions scale to serve millions-even tens of millions-of subscribers with multiple services at multimegabit speeds while also enhancing the customer experience. Another important factor to take into account is bandwidth, as providers must have the capacity to deal with enormous amounts of traffic in the aggregation network. Further stress on the network will come from on-demand services, which, depending on the take-up rate, will create the need for huge amounts of bandwidth from the serving headends to the receivers.
Better customer experience and satisfaction is key for video over broadband delivery. Maintaining good TV picture quality and acceptable channel-change time is essential to ensuring customer retention and ultimate adoption of video over broadband. For optimal customer experience, channel-change time should more no more than one second. There are a dozen or more contributors to channel-change delay, most notably the set-top-box's buffer size and the inter-I-frame gap time of video when it was encoded. Cisco has added enhancements to multicast leaves and joins such that it contributes less than one fifth of the total channel delay experienced.
Preventing denial of service attacks is an important strategy in preventing service disruption. Cisco has added enhancements to multicast routing such that only network specified sources may send multicast streams and has also implemented rate limits in aggregation routers that thwart malicious subscriber behavior.
When congested, the network should grant access to premium content on a per-user basis even. If policy dictates it, web surfing and peer-to-peer applications should not prevent a customer from watching TV content or placing phone calls concurrently.
CISCO INTELLIGENT VIDEO OVER BROADBAND SOLUTIONS
Building on its unique experience in developing triple play residential Metro Ethernet architectures and solutions, Cisco has enriched and developed new features and technologies for Gigabit Ethernet DSL aggregation. To keep the Gigabit Ethernet DSLAM piece interchangeable and as cost-effective as possible, Cisco has defined and documented an architecture that enables triple play service delivery with the smallest subset of common functionalities shared across the different Gigabit Ethernet DSLAM platforms being deployed in the market. This framework has been applied in the majority of recent triple play deployments and offers an unprecedented amount of flexibility and scalability as well as multiple service injection points.
Cisco broadband solutions offer many unique, unparalleled features that address the requirements posed by broadband triple play services:
• Cisco introduced the industry's first asymmetric Gigabit Ethernet optimized video network solution. Video on-demand applications have highly asymmetric traffic patterns, with the bulk of the traffic (video streams) flowing from the network to the subscribers. Cisco's asymmetric design helps operators to build in only as much bandwidth as is necessary in each direction. Deployment of an asymmetric Ethernet architecture retains the low startup cost of a unidirectional network without sacrificing any of the operational benefits of more traditional bidirectional networks. Building this Ethernet capability over an integrated, asymmetric optical infrastructure provides further cost and operational benefits-again optimizing the network for the traffic patterns of VoD. For example, numerous Gigabit Ethernet links in the downstream direction can be deployed to support video streams, with only a single, Gigabit Ethernet link in the return path for control and management traffic. Introducing Cisco's 10 Gigabit Ethernet solutions brings additional bandwidth scalability, while still having the ability to build out asymmetrical bandwidth by using a drop and continue architecture.
• Security mechanisms that are necessary to prevent service disruption and that are standard in Cisco IOS® Software include IGMP and PIM filters, access control lists, and rate limiting.
• IP Multicast with Source Specific Multicast (SSM) provides for bandwidth-efficient delivery of the broadcast service while providing greater simplicity and inherent security than previous versions of multicast routing. While IGMPv3 on the subscriber edge is the most appropriate signaling mechanism, SSM mapping in Cisco aggregation routers allows the installed base of DSLAM and STBs that only support IGMPv2 to be used without compromising the advantages of multicast routing with SSM (PIM-SSM).
• IP QoS ensures the necessary bandwidth, latency, and jitter for video service-level agreements (SLAs) and better customer experience.
• Fast convergence for both unicast and multicast during an outage.
• Broadcast Source Redundancy, which enables the high availability required by the video broadcast service. Cisco has been working for years with major video vendors to develop and incorporate advanced resiliency mechanisms, such as Anycast sources with fail-over notification.
• Load balancing permits optimal use of the available capacity on redundant links by using Layer 2 and 3 techniques.
• Network Monitoring is an important operational task that is easily achieved using currently available Cisco solutions for video over broadband.
Interoperability between network elements such as DSLAMs, core switching/routing and optical transport, aggregation routers, access and home residential gateways with video building blocks such as STB, middleware, video-on-demand servers and video headends is the key to guaranteeing flexibility and scalability but can only be realized by leveraging standard protocols such as IP. Cisco has been working closely with video building-block vendors to support enabling protocols for video, both in our labs as well as in standards bodies.
FUTURE ENHANCEMENTS FOR VIDEO OVER BROADBAND IP
Cisco Systems is currently developing numerous innovations that link the video application to the network with the flexibility and intelligence to adapt to changes in consumer acceptance of video services as well as changes in topology or scale. One such innovation is an approach for intelligent video service admission control and dynamic resource sharing. These innovations make Cisco a trusted partner in scaling video and triple play service well into the future.
CISCO EFFORT IN IP AND VIDEO STANDARDIZATION FORUMS
Looking forward, Cisco is leading an industry effort to bring an open, standards-based scenario to video networking. These efforts help define the mechanisms and protocols for communication between different components in a video over broadband network.
Cisco also participates in:
• Universal Edge standardization efforts
• CableLabs Next Generation VoD standardization efforts
• DSL Forum standardization
• Interoperability with vendors of video building blocks
CONCLUSION
Broadband has not only revolutionized the telecommunications world but is also changing the media industry by opening up a new way to deliver innovative services to tens of millions of users.
Cisco's unrivalled experience in entertainment services helps deliver cost-effective video networking infrastructures to meet aggressive time-to-market demands. More than 10 million subscribers in North America alone are accessing entertainment services over Cisco-based infrastructures. Cisco's innovative video networking solutions help service provider operators to reduce the total cost of video over broadband services
Cisco video over broadband solutions allow service providers to deploy triple play services in a rapid, safe, flexible and scalable manner to meet today's fast changing service requirements. Leveraging best-of-breed ecosystem partners on both the video and integration sides, Cisco is able to provide service providers with a working and scalable end-to-end solution for triple play and video in particular.
Cisco has proven experience in multimedia transport over converged packet networks, superior knowledge of the video-network interface from years of collaboration with major video vendors within a large partner ecosystem, and the proven track record of successful deployments in broadband service providers. This unique combination of attributes makes Cisco the right choice for video over broadband.
