Eliminating QoS Congestion in Video and Triple-Play Networks

In today’s competitive market place, network operators face decreasing revenue from traditional telephony services and a flat-rate pricing model for Internet services. There is a low margin for service providers who offer only Internet services, as well as increased pressure from cable operators who are offering triple-play services over cable infrastructure.

To grow top-line revenue, telecom operators are looking to increase their offerings, meeting the escalating demand for triple-play services and increasing the revenue per subscriber. This convergence of media and telecommunications is becoming the norm and is leading to more deployments of triple-play services over xDSL.

According to a recent report from Infonetics Research, the number of IPTV subscribers in North America will increase more than 40-fold between 2005 and 2009. Meanwhile, in 2005, worldwide IPTV equipment revenue topped $400 million.

To increase revenue and compete against cable TV operators, telecommunications companies are stretching to deliver the best IPTV in conjunction with VoIP and other media services. Unfortunately, telecom networks initially were built to handle only high-speed Internet access.

“Service providers expect huge returns from IPTV, and they are investing heavily in IPTV infrastructure to ensure those returns,” says Jeff Heynen, directing analyst for IPTV at Infonetics Research. “Right now they’re focused on transport infrastructure, upgrading their access networks. … Over the next four years, though, their investments will shift a bit to content infrastructure, so they’ll spend more on things like video-on-demand servers, encoders, content security platforms and headend equipment.”

With a lack of adequate network solutions to cost effectively meet the requirements of QoS, flexibility and reliability when deploying content-rich media, network limitations are preventing the complete convergence of the two industries. Additionally, support and maintenance costs associated with triple play can far exceed capital investments.

To address QoS issues stemming from network limitations, many network operators are over-provisioning. But this approach proves one of the biggest threats to ROI. Over-provisioning is an extremely costly way of addressing the issue since a substantial portion of network cost is the fiber infrastructure. Currently, network operators are using network bandwidth at an extremely low utilization rate of 30 to 40 percent, meaning that more fibers/wavelengths and more ports are needed. Research has shown that QoS problems intensify with the number of hops and the number of ports in the networks. Ultimately, this method drives up capital expenses on both equipment and the underlying infrastructure, making it an unreasonable solution for QoS when deploying IPTV services.

The most successful method of delivering triple-play services and media convergence is by using GMPLS and next-generation transport technologies, which employ bandwidth channelization. With this approach, operators can change radically the economics of offering video and triple-play services over existing networks by preserving resources and provisioning services end-to-end through bandwidth channelization.

By using dynamic bandwidth channelization with signaled end-to-end provisioning, network operators can realize 100 percent QoS for IP video traffic, even with a network load of more than 95 percent. This allows service providers to allocate more bandwidth to popular services. Doing so results in an extremely high level of utilization of infrastructure, contributing to overall reduced capital expenditures.

This channelization technique provides enhanced QoS and multicast functionality for efficient triple-play networks. Video traffic is separated from other traffic via the bandwidth channelization, which ensures strict QoS even at high volumes. TV and video traffic only experience one hop from headend to subscriber. Because the video traffic bypasses the broadband remote access server (BRAS), the functionality is centralized.

There are many technical benefits for using channelization to ensure QoS including:

• Configurable channel size – In addition to being configurable and having high granularity, channels can be symmetric or asymmetric, depending on customer preference, which dramatically increases bandwidth utilization.
• Flexible topologies – Businesses can configure the architecture to build ring, bus, point-to-point or mesh structures.
• Non-hierarchical switching – Channels can be aggregated and switched on VC3/VC4 levels as well as set up end-to-end and switched on sub-VC12 levels. Links can be set up as desired to build large network structures without affecting the characteristics of the transport.
• Signaled end-to-end provisioning – Through this approach, channels automatically can find paths through the network during provisioning and rerouting.
• Multicast – This can provide for point-to-multipoint channels, which are essential to accommodate many media services such as IPTV.
• Generic transport –Traffic can run on many different transport carriers including, IP, SDH/SONET and gigabit Ethernet optics.

By using dynamic next-generation optical transport technology with end-to-end provisioning, all types of traffic (IP, Ethernet, SDI and ASI video, etc.) can be routed over separate channels. This helps minimize issues of jitter, packet loss and traffic delays while allowing operators to transfer video in real time over large networks as compressed IP traffic or as uncompressed 270mbps digital video signal. Additionally, this solution is based on international standards and is compliant with emerging NG-SDH/SONET and GMPLS standards. With standardized interfaces, operators easily can upgrade existing networks to better utilize capacity.

Today, telecom operators are using this next-generation technology to provide video, voice and data cost effectively, which attracts and retains subscribers. Furthermore, operators can upgrade existing networks to better utilize capacity and offer additional, comprehensive services without incurring costly network buildouts that come with over-provisioning

Per Lindgren is vice president of business development and a founding member of Net Insight Inc. He can be reached at per.lindgren@netinsight.com.

Net Insight Inc. www.netinsight.com

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