The Ideal Headend Evolution to Carrier Class WHITE PAPER Today’s successful cable operators are ramping up their networks to deliver advanced services—HD video-on- demand (VOD), tiered high-speed data, voice-over-IP (VoIP) and commercial services. MSOs are focused on improving network reliability and customer satisfaction, and understand the importance of “carrier-class” infrastructure. In order to reach the highest level of delivering the extremely reliable services customers expect, MSOs must begin thinking about the “ideal headend.” Path to the ideal headend In the most basic terms, an ideal headend is the key to enabling MSOs to grow their system without major rebuilds each time new services are added. In the past, these networks were typically designed and built to meet only the needs of the day. To be successful in today’s brutally competitive environment, the mindset has to shift. Cable operators must look five to 10 years into the future and design a system that can easily accept and integrate new equipment into the existing network—a system that can deliver voice, video, data and wireless services for the quadruple play. As high-tech hardware, such as VOD servers, is introduced to the network, connectivity infrastructure must be designed to “wrap” the new equipment. Keeping in mind the old cliché that a network is only as strong as its weakest link, proper network documentation, a solid foundation of RF and fiber signal management, and power distribution solutions must work hand-in-hand to make network reconfigurations faster, easier to perform and far less risky to implement. This flexibility and reliability is only achieved by building the headend of the future. One path is to use modular components that enable operators to easily expand their systems to offer the best performance. The high density of these system components also requires a much smaller footprint within the facility. Let’s take a look at some of the criteria for designing and building an ideal cable headend—power distribution, circuit-switched telephony, fiber-to-the-premise (FTTP) support and fiber cable management, data-center connectivity solutions, digital signal cross-connects and RF signal management. Power distribution Building a future-proof headend begins with ensuring you have the necessary power distribution facilities in place to support new equipment and services. The type of power required will be determined by the services to be delivered across the system. However, MSOs planning to deliver telephony services over IP (which include lifeline or E-911 services) will have to change their power structure. Traditionally, most of the equipment found in an MSO’s headend was operated by AC power. However, AC power is not built to handle telephony services because it cannot easily provide continuous, uninterrupted power. Therefore, in the ideal headend, cable operators should be looking at incorporating some type of DC power configuration with battery back-up. Today, most cable headends use some type of hybrid power—some equipment powered by AC and some by DC. But telephone companies are almost exclusively DC powered, so for cable operators to emulate the carrier-class services of their telecom competitors, they will need to adapt their power distribution to enable delivery of additional services. DC power and redundancy will become critical issues. For instance, the systems that power the high-speed Internet are extremely power hungry, drawing up to 70 amps per unit, and there are very specific requirements for continuously powering these devices. Although DC requires more initial cost during installation and uses more real estate, the improvement to network reliability cannot be overstated. Capital expenditures must be weighed against the possibility of higher operational costs down the road. Truck rolls and technicians are a large part of operational costs so, simply put, upping the reliability lowers the number of service calls required. Cable MSOs ideal headend—the evolution to ‘carrier class’ Page 2 THE CABLE MSO’S IDEAL HEADEND—THE EVOLUTION TO ‘CARRIER-CLASS’ seirettaB tes neG refsnarT h ctiwS CA oT slenaP buS le naP esuo H seirettaB CD kcar tnempiuqE slenap esuf rewoP noitubirtsiD draoB BFDB CD sdaoL hctiwS C A laicremmoC yradnoceS rewoP seitilicaF/gnidliuB yramirP rewoP sreifitceR There are other good reasons for converting headends to DC power despite the conversion costs. Future services, including VoIP, VOD and IPTV, will up the ante in terms of a provider’s ability to quickly add, turn up and reliably maintain whatever service bundle each customer chooses. Problems relating to power in the new FTTP networks that offer “full suite” services will simply be unacceptable. The impact of DC power is immediately apparent if one considers several attributes: • DC power is conditioned power, enabling equipment to run more smoothly and efficiently • Systems can be configured for longer standby at hubs or nodes • Since equipment is direct-wired rather than plugged in, connections are unlikely to disconnect • Each piece of equipment can now be individually fused • There is A to B power redundancy to each individual piece of equipment • A DC power plant is easier to monitor • Cable management, a huge consideration in FTTP networks, is more cleanly managed Power is never a no-brainer, especially when it comes to doing the “heavy lifting” for the network. If the power fails, the network fails. If the network fails, customers look elsewhere for more reliable service. In the ideal headend, the right power scheme is employed to offer uninterruptible delivery of advanced IP services. Circuit-switched telephony In typical cable system, circuit-switched telephony is accomplished by headend equipment that “talks” to a telephone switch at a telephone company’s central office. However, with the advent of IP telephony, those systems are rapidly migrating to some form of packetized transport. Telephony is exiting the days of circuit switching and entering the new world of packetized switching. With that in mind, an ideal headend will need to operate both systems simultaneously for a period of time, realizing that at some point the circuit-switched solution will disappear. This hybrid operation of two systems will be necessary as packet switching gradually evolves to become the dominant telephony system. Throughout this evolution, cable operators must also have the ability to reconfigure their circuit-switched customers to the new packet-switched operation. Customer migration onto a packet-switched system must be completely transparent. Supporting FTTP New FTTP technologies are also requiring MSOs to ensure their networks provide a means to upgrade and expand to meet any future demands. Although MSOs already have high bandwidth hybrid fiber/coax (HFC) architectures in place and are capable of delivering bandwidth-hungry services to residential and small business customers, they still must look to the future. Their core infrastructure must be flexible and scalable enough to allow them to compete with the massive amounts of fiber being driven deeper into the access. An ideal headend will enable MSOs to realize the full benefits of the broadband systems they already have in place, while allowing them the ability to deliver next- generation services like VOD, HSD, and VoIP that are carrier grade. Cable MSOs ideal headend—the evolution to ‘carrier class’ Page 3 Fiber Frame Softswitch IP PSTN SS7 Router VMX Trunking Media Gateway CMTS O to E Converter CALEA Mediation Announce- ment CMTS CMTS Video Voice Packet Voice Data PowerWorx DC DC DSX-1 DSX-3 RF Worx True N et PowerWorx DC DC PowerWorx DC DC Legacy HDT RF Worx RF Worx A/V Patching Video Fiber Frame Fiber Frame ADC Telecommunications, Inc., P.O. Box 1101, Minneapolis, Minnesota USA 55440-1101 Specifications published here are current as of the date of publication of this document. Because we are continuously improving our products, ADC reserves the right to change specifications without prior notice. At any time, you may verify product specifications by contacting our headquarters office in Minneapolis. ADC Telecommunications, Inc. views its patent portfolio as an important corporate asset and vigorously enforces its patents. Products or features contained herein may be covered by one or more U.S. or foreign patents. An Equal Opportunity Employer 101203AE 11/05 Revision © 2005 ADC Telecommunications, Inc. All Rights Reserved Web Site: www.adc.com From North America, Call Toll Free: 1-800-366-3891 • Outside of North America: +1-952-938-8080 Fax: +1-952-917-3237 • For a listing of ADC’s global sales office locations, please refer to our web site. WHITE PAPER Fiber cable management The ideal headend will be designed not only to enable cable operators the flexibility to add new subscribers, but also easily reconfigure the network to adapt to customer churn. The principles of a good fiber management system that apply to telecom service providers are equally as important to cable MSOs. Fiber cable management is broken down into a few key principles, the first of which is to develop clear routing paths that are obvious to any technician at a glance. In other words, routing the fiber correctly should be intuitive and easily accomplished. Next, fiber cable should be physically protected to prevent damage as a result of technicians working on other parts of the rack, cabinet or cable-management device. Measures should be taken to avoid damaging, pulling, stretching, crushing or pinching existing fibers in the vicinity of the work area. Another key is bend-radius protection. As fiber is bent, the radius can become too small and allows light to escape the core and enter the cladding. The result is insertion loss in the fiber or a macrobend that decreases the signal or, in extreme cases, causes complete signal loss and data-transfer failures. Finally, an integrated slack-storage strategy or system is necessary. Each fiber, due to the high tolerance needed, is normally terminated in the factory to eliminate the high costs involved with field terminations. This typically results in fixed cable lengths and patch cords. Once the technician arrives at the job site to make a connection, the fiber cable or patch cord may be longer than what is actually required. Therefore, a system must allow the proper storage of the slack—the difference in length between what is actually needed to physically make the connection and what the technician actually has to work with. Data center connectivity Historically, cable providers only had a handful of data cables in the headend, mostly connecting computers to the network. But today, data is a large part of the headend, especially to provide high-speed Internet services. Because of the increased demand for high-speed data, cable management solutions must be incorporated for structured cabling solutions. Offering data-based services requires the cable operator to transport traffic from the Internet service provider (ISP) to each server and onto the cable modem transport system (CMTS) to customers. As with other areas of the ideal headend, the data-center portion of the network must be completely flexible and scalable. In fact, data delivery has become so important to today’s MSOs, the ideal headend is beginning to transition from just housing RF signal-management equipment into resembling an actual data center. Unlike telecom providers who are scrambling to get fiber capacity to the home, MSOs already have the large pipe they need. Their focus now should be on ensuring they have the proper equipment in the headend to deliver those services. Conclusion Just as telecom providers must adapt their networks to deliver services like IPTV, MSOs have to take steps to ensure they can deliver the data and telephony services as a bundled offering to customers. Delivering video has always been the “bread & butter” for the MSO, but gearing up cable systems to deliver data and voice greatly lowers the tolerance for error in the system. Building the ideal headend that is flexible, scalable, and reliable for delivering triple-play bundles will enable the delivery of carrier-class services that customers expect and demand. ADC’s time-tested products and professional services help enable cable operators to design and build the reliable and flexible multivendor headends, and provide firm footing on which to compete in the triple- and quadruple-play services space. . lowers the number of service calls required. Cable MSOs ideal headend the evolution to carrier class Page 2 THE CABLE MSO’S IDEAL HEADEND THE EVOLUTION TO. customers expect, MSOs must begin thinking about the ideal headend. ” Path to the ideal headend In the most basic terms, an ideal headend is the key to