Telcos are counting on IPTV to complete the video leg of their triple-play service offerings. However, in order to achieve real competitive advantages, any service provider looking to deploy IPTV needs to first ensure that its network has the necessary capabilities to deliver this new on-demand HDTV content.

While IPTV is hot and getting lots of press, one issue is often overlooked: how will content and service providers provide sufficient high definition television (HDTV) programming to make IPTV truly competitive? Beyond the issue of generating the content, providing it must take into account issues such as transporting HDTV signals from live events or any origination point and immediately streaming or archiving them for later download from video on demand IPTV servers. To enable service providers to supply the level of video quality that consumers demand, the networks that deliver this content must also be scalable and flexible to provision bandwidth on a per-customer or per-transmission basis.

For service providers, the key to achieving a competitive advantage in IPTV is choosing a network provider that offers the right capabilities. This decision should be based on the network’s flexibility of bit rate, availability of bandwidth and codecs, and the capability to multicast for archiving and streaming purposes.

Arguably, the consumer electronics industry is on an unstoppable drive toward HDTV market penetration, and more and more broadcasters are looking to carry live HD events. These are the most challenging programs to transport because the broadcasters need to supply a standard definition (SD) and HD feed from the field.

Since the majority of customers still need SD programming, broadcasters must support the transport bandwidth and quality required for both SD and HDTV for live on-location events, such as sports events or awards ceremonies. The preferred approach is to transmit the SD and HD feeds across the same network, such as an OC12 or OC48 all fiber optic network. This would allow provisioning of bandwidth in 0.5-Mb increments, enabling the broadcaster to select the right cost effective and high-quality solution for its applications.

A network that supports both SD and HD IPTV must by necessity also support standard networking protocols such as Ethernet, ATM, and Dynamic Synchronous Transport Mode (DTM) with the flexibility to provision bandwidth across a broad range of speeds. For instance, a DS3 network can only provision up to 45 Mbits/s. If the network must support more than 45 Mbits/s, than the customer must purchase larger telecom standard circuits, such as OC3/OC12/OC48, or the service provider must send the feed over an MPLS network, which cannot offer 100% QOS and is difficult to monitor. A DTM network, on the other hand, can scale from 0.5 Mbits/s up to 2.4 Gbit/s, providing the flexibility to do occasional use or dedicated services at any rate customers want.

Flexibility of bit rates is particularly important for HDTV. To ensure quality video, the transmission rates should not be constrained by limitations from the codecs or telcom network standards, such as 45 Mbits/s on a DS3. For quality video, service providers need to be able to provision bandwidth across a range of 500 Kbits/s to 1.4 Gbits/s. That allows the customer to easily decide the tradeoff between buying more bandwidth instead of increasing compression. Increasing compression rates would likely result in higher codec capex cost (due to the need for more processing), greater latency (time to compress), degradation of quality (more artifacts), complicated configurations, and potential for equipment failure.

For contribution-quality back haul of production, sports, and other live events, broadcasters and customers generally prefer to eliminate the costs and signal degradation of the codecs and transmit native uncompressed video. For high-quality multiplexed transmissions, the network should support bandwidth provisioning in 0.5Mbits/s increments up to the full 214 Mbits/s DVB-ASI standards. These attributes require a flexible, lower cost, high-speed network to support the greater network demands.

Besides bandwidth, bit rates, and codecs, another concern with HD IPTV is the network's ability to efficiently transmit feeds from the source to multiple destinations (point to multipoint). A network with multicasting capabilities can be used to efficiently archive footage for later download on an IPTV system and to provide live feeds to other destinations. Many providers will have multiple headends and, therefore, will want to deliver the content to several locations simultaneously. Without multicasting capabilities, the network must transmit multiple replicated streams to various locations (such as in ATM or MPLS), which is an inefficient use of bandwidth. This becomes very apparent at the higher bit rates of full ASI (214 Mbits/s). It is imperative to optimize the route used by the feeds traversing the network in order to reserve and guarantee that the necessary bandwidth will be available when needed. Having a plan for a backup path is also critical for troubleshooting and rapid re-routing in the event of a network outage. A network with multicasting capabilities is better able to support optimized routing and rapid re-routing.

To be sure, many telcos are counting on IPTV to complete the video leg of their triple-play service offerings. Cable and satellite services are looking at IPTV to complement their existing video on demand services. Regardless of the type of provider—telecommunications, cable, or even satellite—the ability to enable a rich HD IPTV experience for customers is directly related to the quality, flexibility, and capabilities of the underlying fiber-optic network.

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