As the market shifts toward ubiquitous high definition content with more personalization and greater interactivity, Alcatel-Lucent (News - Alert) is driving the development of smart, IP-based, video-centric networks that offer subscribers a consistent and high-quality, personalized and interactive viewing experience. Release 2.0 of the Triple Play (News - Alert) Service Delivery Architecture provides the foundation for this experience by delivering the performance, value creation and optimization required to assure an uncompromised user experience and efficient content delivery, now and in future.

 

Innovation is rapidly changing the television landscape, expanding the user’s experience and service expectations. Service providers around the globe are embracing this opportunity by leveraging their IP-based networks to enhance and evolve the TV and video viewing experience. They are making their entertainment services more compelling for subscribers, while opening new revenue opportunities. These initiatives, however, significantly increase the per-subscriber service bandwidth and total network traffic levels as a result of the mass-scale unicasting with high concurrency (simultaneous users and service utilization). In addition, with the growing demand for high definition (HD) content and IPTV (News - Alert) services in several rooms in the home, operators must ensure their delivery of a high-quality TV experience is never jeopardized. Toward this end, Alcatel-Lucent is making significant enhancements to its already successful Triple Play Service Delivery Architecture (TPSDA) solution. These enhancements are collectively referred to as TPSDA 2.0.

 

TPSDA 2.0 introduces application layer intelligence to its underlying network elements, enabling them to cache, store, stream and splice video content in a coordinated and hierarchical manner, as well as to characterize application layer content traversing the network. These capabilities provide an unprecedented user experience with an optimized total cost of ownership (TCO), and enable a new level of mass personalization and ubiquitous HDTV. Specifically, TPSDA 2.0 delivers the following capabilities and benefits:

 

• Assures and optimizes the delivery of HDTV and multi-room services with unparalleled quality of experience (QoE). These capabilities are enabled and cost-optimized by integrating caching functions into the TPSDA network elements to support immediate channel changing and reliable delivery, which are known generically within standards organizations as Fast Channel Changing (FCC (News - Alert)) and Retransmission (RET) respectively.

• Optimizes delivery of the unicast content that will result from mass personalization of TV services (including targeted advertising). TPSDA 2.0 extends the caching function used in FCC/RET from a few minutes to hours, bringing the unicast delivery closer to the subscriber to significantly reduce costs. In addition, implementing ad splicing in the TPSDA network elements enables the introduction of targeted advertising in a cost-effective way, leading to new sources of revenue.

• Creates new value for Internet video content by enabling users and content owners, application owners, advertisers and other key players in the value chain to choose the QoE they want, for the content they care about, and at a price they are prepared to pay. Enabled through a new portfolio of managed online services, this capability assures the quality of specified, on-line applications by characterizing the content at the application layer (for example, on-line gaming or “over-the-top” (OTT) video), and leverages TPSDA’s end-to-end policy enforcement to assure its delivery, for a high-quality experience.

 

Selected by more than 55 operators, TPSDA is the blueprint architecture to accelerate the IP network transformation for delivery of video, voice, data and entertainment services. Illustrated in Figure 1, TPSDA is an end-to-end architecture designed from the ground up to deliver high subscriber scale, high bandwidth throughput per subscriber and high concurrency — the fundamental attributes for a new era of “always-on”, mass market residential broadband services.

 

First-generation broadband network solutions tunnel best-effort Internet traffic across the network. TPSDA significantly improves on this by providing distributed, fine-grain policy enforcement with centralized policy control. It enables providers to deliver multiple services to subscribers, including managed services such as IPTV, voice and managed online services, as well as unmanaged services such as High-speed Internet (HSI). TPSDA is unique in utilizing all parts of the network to deliver and enforce policy end to end.

 

 

TPSDA leverages industry-leading broadband access, optics, Carrier Ethernet and service-aware IP technologies from Alcatel-Lucent, and combines them with robust subscriber and network management, security capabilities, and a comprehensive suite of design, deployment and integration services.

 

In the long run, service value drives customer loyalty and market share. Now is the time for service providers to take IPTV to the next level and make the service more personalized and more interactive, with ubiquitous HD content.

 

TPSDA 2.0 begins by addressing linear TV delivery and its challenges with HD and multi-room offers. Solving these challenges is crucial to enabling an operator’s baseline portfolio of IPTV services. Moreover, the technology used here provides the foundation for more advanced personalized and interactive services (which are described later in this paper).

 

With linear TV programming (that is, traditional broadcast TV delivered over IP), all channels are delivered to the edge of the operator’s network, at which point only the channel (or channels) being watched in a given household are switched onto that subscriber’s broadband connection. Using IP multicast technology, a single copy of each channel is pushed onto the network at the video office and thereafter the channels are replicated as required within the network until each is distributed to the edge of the network. Multicast is extremely efficient in its use of bandwidth (see Figure 2).

 

The process of switching a channel onto a subscriber’s broadband connection is triggered by the subscriber pressing the remote control. When detected by the set-top box (STB), a signal is sent into the network and the requested channel is switched onto the subscriber’s broadband connection.

 

 

The emergence of ubiquitous HD content and multi-room offerings brings new challenges to IPTV operators. Both increase the amount of bandwidth to each household, increasing the likelihood of transmission errors from higher Digital Subscriber Line (DSL) capacities and/or noisy home networking technologies such as powerline – a technology that is significantly noisier than Ethernet over dedicated Category 5/6/7 wiring. Since linear IPTV is User Datagram Protocol-based, there is no inherent mechanism to retransmit the damaged video content. As a result, visual artifacts appear on the TV screen when errors occur, deteriorating the user experience. While true for all video encoding techniques, MPEG4 — an enhanced encoding technique used for HDTV — is particularly sensitive to transmission errors, thus compounding the issue.

 

MPEG4 brings an additional challenge: aggressive encoding, done to reduce bandwidth, means a longer interval between I-frames, the critical video content MPEG4 must receive before it can begin decoding. This delay results in a slower channel changing time, which can be as much as 3 to 5 seconds, based on anticipated MPEG4 compression settings.

 

These issues are the driving force behind FCC and RET, the application-level techniques developed to avoid jeopardizing the user experience. Illustrated in Figure 3, centralized server-based implementations of FCC and RET are triggered in the home by the user and STB respectively. When the user changes a channel, a message is sent into the network to have the new channel switched onto the broadband connection via multicast (this part remains the same). An FCC server, however, also detects the channel change request and sends a burst of unicast video content – beginning with the I-frame – to the subscriber’s STB with enough information to allow an immediate channel change along with several seconds of video information to play out while the STB synchronizes with the new multicast stream.

 

RET works in a similar manner except that the STB triggers the retransmission request. When a STB detects a video error in its buffer, it requests a retransmission of the missing content and the end user never sees a visual artifact. A centralized server-based FCC/RET implementation overcomes the challenges outlined and is sufficient for low concurrency levels.

 

 

The issue with centralized server-based FCC/RET implementations, however, is the amount of unicast bandwidth used: eight times more than the total bandwidth required to transport all multicast channels in the first place. Based on internal modeling of a typical tier 1 IPTV operator, the amount of unicast bandwidth required for FCC/RET is approximately 12.5 Gb/s whereas the total multicast bandwidth is approximately 150 Mb/s. Illustrated in Figure 4, this introduces a new dynamic to the economic equation: the cost to transport unicast traffic from servers located deep in the network to specific subscribers connected at the very edge of the network.

 

 

Enhanced with application layer intelligence, TPSDA 2.0 is able to deliver immediate channel changes and retransmission with considerable cost savings while assuring a superior, uninterrupted viewing experience (see Figure 5). Based on TPSDA 2.0’s distributed and integrated FCC/RET function in the network elements, the bandwidth in the core network is reduced to zero; in the aggregation network, up to 1 Gb/s of bandwidth is saved and on the precious broadband access node uplink hundreds of megabits of bandwidth are saved.

 

TPSDA 2.0’s implementations of FCC and RET are completely standards-based and middleware-independent. They adhere to the recent Digital Video Broadcasting (DVB) standard for RET using Real Time Protocol (RTP) and Real Time Control Protocol (RTCP), and to recent Internet Engineering Task Force work extending this approach for the FCC as well as the new DVB task force on FCC.

 

 

FCC/RET demonstrate the volume of unicast bandwidth generated but this is really just the tip of the iceberg, a sign-post of what’s to come. As operators deploy more personalized services with greater interactivity, the amount of unicast traffic will increase. More importantly, the popularity of such services will mean a much higher concurrency rate than witnessed for FCC/RET. For example, as at 80 percent concurrency is anticipated for popular Pause Live TV (PLTV). The result will be an explosion of unicast traffic and an excessive TCO to accommodate the massive scaling and transport of personalized services that are high bandwidth and high concurrency, if traditional centralized application and content servers are the only option.

 

Clearly, for IPTV to remain a winning proposition for service providers, they need an evolving architecture that enables them to take IPTV to the next level, beyond initial linear TV offerings and into the realm of personalized and interactive applications. This is what TPSDA 2.0 does.

 

To begin, the architecture must address the massive scaling requirements of personalized services (including HDTV), which are inherently unicast in nature. TPSDA 2.0 sets the foundation for these requirements by optimizing content delivery closer to the subscriber. This is crucial to an operator’s TCO and profitability since network-based services such as TSTV, PLTV and nPVR are becoming extremely popular but can be expensive to deliver as they impose massive bandwidth demands on the network when used with high concurrency.

 

With the cost of memory and processing resources declining faster than the cost of transport, market forces are converging, creating new opportunities to innovate and rethink traditional approaches to content distribution architectures.

 

Illustrated in Figure 6, centralized storage – the traditional approach – is moving toward decentralized server solutions, exchanging costly transport dollars for inexpensive memory dollars. Furthermore, the cost of real estate for decentralized servers combined with their power, cooling, interconnect ports and maintenance costs continues the transition, pushing storage into the network, closer to subscribers.

 

 

By distributing and integrating the application layer capabilities that were previously hosted in servers into the network elements, TPSDA 2.0 provides operators with a scalable and cost-effective foundation to serve all of these new service options. By making it possible for operators to lower their TCO, TPSDA 2.0 enables them to address the new requirements and to grow and expand their business to more homes, with more HDTV, more multi-room and more personalized and interactive services. For example, extending the FCC/RET buffer size in TPSDA network elements (refer to Figure 6) from minutes to hours creates an optimized platform upon which to deploy scalable PLTV and TSTV with high levels of concurrency. Being network-based, these buffers cache all channels, giving each household the ability to rewind any channel, not just the one they’re currently watching.

 

By caching content at the edge of the network, unicast traffic is kept local and does not incur the high transport cost associated with centralized storage deep in the network. Furthermore, by pushing the cache and supporting processing requirements closer to subscribers, the performance requirements are lower as fewer subscribers must be supported per element, providing a consistent and high-performance user experience.

 

The technology that enables TPSDA 2.0’s assured and optimized content delivery solutions plays a key role in the Alcatel-Lucent Targeted and Interactive IPTV Advertising Solution. Designed to increase IPTV revenue by making it easier for advertisers to reach the most attractive potential customers with ads that are more timely and relevant, it also offers a variety of interactivity features that enable consumers to view additional information about products that interest them. The solution gives IPTV operators the ability to insert ads into TV programs that are aimed at particular communities of interest and even specific households. TPSDA amplifies and extends the power of service providers’ IP networks by distributing an array of new capabilities throughout the network, including linear ad insertion, which is central to the delivery of targeted ads.

 

Illustrated in Figure 7, TPSDA 2.0 provides integrated ad splicing and insertion along with novel IPTV channel and ad activity tracking functions. This means an ad can be spliced into the video stream at the appropriate TPSDA network element, depending on the level of personalization. Further, the access network element coordinates with the splicing function, in order to discard the default ad on a per-subscriber basis, and to report user IPTV viewing behavior (to enhance the ad decision and advertising reconciliation process).

 

 

TPSDA 2.0’s distributed and integrated ad splicing function knows when to insert an ad based on digital cue points in accordance with the Society of Cable Telecommunications Engineers (SCTE) industry standard, known as SCTE 35. The ad splicer communicates with, and gets ads from, an ad server using the SCTE 30 standard. If the ad server decides to take advantage of an “avail” — the industry term for an ad insertion opportunity — it sends the ad stream to the ad splicer and the ad splicer “switches” it into the main transport stream as dictated by the digital splice points.

 

As depicted in Figure 7, the splicing function can be integrated into TPSDA elements within the video office (for national ads) or integrating into network elements closer to consumers for more granular advertising opportunities (referred to as local and zoned advertising). By offering this level of integration across various network locations, a dramatic simplification of operations and ease of use can be realized as well as the ability to provide more granular targeting of ads.

 

The combination of ad insertion and FCC/RET assures that the quality of an ad and its carrier TV stream is premium. But it also addresses another issue: because the ad insertion function alters the actual linear TV stream by splicing ads into it, a problem could arise when a subscriber changes a channel or the STB client requests a retransmission while the inserted ad is played out. For example, a centralized FCC/RET function uses “pre-splice” cached content of each TV channel to perform its function and it will not know about the new ad that was inserted at the local, zoned or personal level. When a subscriber changes a channel, the FCC content from the requested channel may not contain the same content as the actual stream when it arrives at the STB. This could lead to frame synchronization problems at the STB and a different ad could exist in the FCC stream than the main TV channel, which could confuse the subscriber. Similar issues could arise with RET if the frames deemed to be missing occurred during the time a local, zoned or personal ad was spliced into the stream. By tightly coupling FCC, RET and ad insertion within TPSDA 2.0, these issues are avoided in an elegant and efficient manner.

 

TPSDA 2.0’s assured and optimized content delivery also applies to over-the-top content. Integrated application assurance allows operators to embrace OTT content as an opportunity through a positive, value-centric approach. TPSDA enables operators to offer a new portfolio of managed online services, which creates new value by enabling users, content owners, application owners, advertisers and other key players in the value chain to choose the QoE they want, for the content they care about, and at a price they are prepared to pay.

 

Illustrated in Figure 8, managed online services are fully integrated with subscriber and policy management. TPSDA 2.0 can be configured to characterize application layer content traversing the network from the open Internet and mark specific application layer content (such as on-line gaming or OTT video). Once marked, the content is extracted from the bandwidth allocated for HSI access service and delivered to specified consumers in a managed service queue, leveraging TPSDA’s end-to-end policy enforcement to assure a high quality experience.

 

 

Furthermore, TPSDA 2.0 supports caching of short form content, which includes ads, live channels for PLTV and web-derived content. The exact business model to be employed for the caching of web-derived content is being investigated by Alcatel-Lucent and the Company’s operator customers. This subject is expected to be important in future developments.

 

As the market shifts toward ubiquitous high definition content with more personalization and greater interactivity, Alcatel-Lucent is driving the development of smart, IP-based, video-centric networks that offer subscribers a consistent and high-quality, personalized and interactive viewing experience. TPSDA 2.0 provides the foundation for this experience by delivering the performance, value creation and optimization required to assure an uncompromised user experience and efficient content delivery, now and in future.

 

 

TPSDA 2.0 uses intelligent network elements to deliver a distributed, end-to-end network architecture that spans access, aggregation and the video office. These elements are the Broadband Service Access Node (BSAN), Broadband Service Aggregator (BSA) and Broadband Service Router (BSR) respectively. Illustrated in Figure 10, these elements are delivered through Alcatel-Lucent products that are industry leaders in their respective categories. TPSDA has been selected by more than 55 operators as the foundation for their strategic, next-generation residential broadband networks.

 

 

The time is ripe for service providers to take IPTV to the next level and offer their subscribers more personalization and greater interactive, ubiquitous HD content. They can deliver these advanced services by leveraging the unique attributes of IPTV as a distribution mechanism. More than 55 IPTV operators have made strategic investments in TPSDA. Now, TPSDA 2.0 provides the features and functionality that will enable operators to go from being “in the game” to “winning it.”

 

Alcatel-Lucent is a recognized leader in IPTV, with the number 1 position in IPTV middleware subscribers (2+ million), TPSDA deployments (55+) and IPTV solution integration projects (50+).