Fujitsu Gigabit Ethernet Solutions
Overview Cable networks are quickly evolving from basic analog TV distribution systems to broadband multiple services networks supporting hundreds of digital video channels, CD quality music channels, cable modem data services, voice services and services. The residential broadband services market is highly competitive with MSOs, direct satellite broadcasters, and telcos striving to attract and retain their residential customers. represents a key service offering that differentiates MSOs from their direct satellite competitors, while reducing cable churn and improving overall business margins. The Fujitsu solutions for transport networks ensure an MSO can easily and cost effectively launch new services. systems allow a customer to select from a wide library of digitally stored movies and shows, giving them the control to watch entertainment on their own schedule. No more trips to a video store on a rainy evening or scheduling your life around a fixed programming schedule. provides entertainment flexibility. Movies and entertainment shows, referred to as programming content, are stored in a digitally compressed form on a number of disk drives, similar to the hard disk drives found in home computers. servers running special software control the flow of programming content from the hard disk drives to a residential set top box. A home user simply selects a movie or show from a menu of choices displayed on their set top box and within a few seconds, their entertainment choice (programming content) begins streaming into their set top box (see Figure 1). In addition to watching what you want, when you want it, most services provide VCR-like controls to stop, pause, fast reverse and fast forward the movie. STB Disk Drives s Figure 1: Overview For your convenience, a list of acronyms can be found at the end of this document. 1
Applications While normally associated with MOD, a infrastructure actually allows a number of different service types to be offered, including: Movies on Demand (MOD) This primary service allows a residential customer to order any movie from a large library of stored movies. The service is similar to picking a movie from a virtual video store, without the hassles of driving to a real video store, renting the movie and then returning the VHS tape or DVD on another day. Subscription on Demand (S) S is a subscription version of, allowing customers to watch all of the programming content for a premium channel on their own time schedule. For example, the entire programming content for HBO for the month of October could be stored on the disk drives. For a small additional monthly fee, HBO customers can opt for an enhanced service (HBO S) allowing them to view any of the HBO programming for that month, at their convenience, using the network. This service enables entertainment on your own terms and on your own schedule. Networked Personal Recorder (PVR) PVRs are becoming an increasingly popular method to record TV shows and allow time-shifted viewing. A PVR incorporates a hard disk drive into the set top box in order to record digitally compressed programs for later viewing. Several high-end cable set top boxes are available with PVR functionality built into the units. The high cost of these advanced STBs remains an issue for many cable customers. As an alternative approach, MSOs can provide networked PVR services that do not require hard disk drives in every set top box. With a system in place to support MOD and S, simply adding additional storage to the existing system allows all programming content to be stored. Users can watch their favorite shows when they want, similar to locally recording the program on a VCR or PVR. 2
Architectures systems can be deployed in one of three fundamental architectures as illustrated in Figure 2. Each of these methods has relative strengths and weaknesses that can be evaluated for a particular metro area or application. Headend Headend Headend Centralized Distributed Hybrid Figure 2: Architectures The Centralized method deploys a single, large system at the headend with streams transported across the network to multiple s. Since only one system is required, this approach tends to lower hardware and software costs. In addition, receiving the programming content (asset reception), managing the programming content (asset management) and overall operating expenses are lower with this single, centralized architecture. Historically, the drawback to this approach has been the high network bandwidth requirements and transport costs associated with sending out the streams from a single location. A large metropolitan area may require 20,000 to 40,000 streams during peak usage, which is the equivalent of almost 200 Gigabit Ethernet channels. Fortunately, DWDM solutions have dramatically lowered the cost of these core transport networks in the last two years, making DWDM and the centralized architecture the preferred method for successful services. With Distributed architectures, multiple systems are deployed at each of the secondary or s. All programming content (assets) are duplicated at each of the s, with each distributed system serving its own small area. This approach eliminates or reduces the bandwidth and transport costs across the core network. However, the approach requires that many smaller servers and associated storage be deployed at multiple s, greatly increasing equipment costs. In addition, each of these systems must be actively managed on an ongoing basis, including constantly updating the stored programming content across multiple sites. Asset management, asset distribution and operating expenses across multiple sites are all major issues with this approach. The Hybrid architecture is a blend of the centralized and distributed models. Smaller servers are deployed at the s but are limited in both size and storage to only the most popular movie selections. A larger platform is installed at the headend with a deep library of movie and programming content. Since new movie releases are by far the most popular viewing choice, these selections can be streamed 3
directly from the smaller, distributed systems, minimizing transport costs across the core network. The system located at the headend has a large repository of several hundred to several thousand movie titles, acting as a backup to fulfill any movie request that is not stored on the smaller, distributed platforms. The hybrid approach has lower equipment costs than a pure distributed model because the systems at the distribution sites are smaller in size and capacity. However, this method still tends to be more expensive than a centralized approach, and the same asset management, asset distribution and multiple operating expenses exists as with the distributed model. The hybrid approach does lower the bandwidth requirements across the core transport network. IP Fundamental to Networks The higher capacity and lower cost of GigE ports, combined with the wide availability of Layer 2 Ethernet switches and Layer 3 routers to perform IP switching and aggregation functions have made IP the leading protocol for networks, which is a major change for most cable networks. Traditionally, digital video channels have been distributed across cable networks using the DVB-ASI format, illustrated in Figure 3. The DVB-ASI signal specifies a physical coax port running at 270 Mbps, with the capacity to carry up to 70 digital video channels in the MPEG-2 TS format. DVB-ASI remains the primary method for interconnecting headend equipment and transporting regular digital video programming channels to QAMs located at the s. DVB-ASI Envelope MPEG-2 TS (i.e., Digital Channel) Figure 3: DVB-ASI Most vendors have migrated to IP as the preferred output format for streams, as well as transport across the network. As the popularity of services grows, the number of output streams can become very large. A GigE output port can accommodate up to 240 digital video streams or channels. Utilizing GigE ports can dramatically reduce the number of output ports required on a system, thereby reducing costs. Since GigE is a widely adopted and deployed interface in data networking markets, MSOs benefit from volume cost efficiencies and cost reductions. Finally, utilizing IP allows MSOs to deploy standard Layer 2 Ethernet switches to perform stream switching and aggregation. 4
While IP may be the perfect choice for output streams and network transport, the IP headers must be stripped off the MPEG-2 TS packets prior to QAM/RF modulation so that the digital video signal is compatible with the millions of deployed residential set top boxes. Standard QAMs only provide a DVB-ASI input, so an IP to ASI gateway is used at the s to remove the IP headers from streams prior to QAM/RF modulation as shown in Figure 4. Newer GigE QAMs are being introduced that provide standard IP/Ethernet interfaces and remove the IP headers internally prior to the QAM/RF modulation. IP to ASI GigE QAM GigE QAM GigE QAM Figure 4: QAM/RF Modulation Getting to the core of A modern implementation incorporates each of the individual elements into an overall service and network solution as shown in Figure 5. servers and storage from SeaChange, Concurrent Computer Corporation or ncube are centrally located at the master headend. GigE output streams feed into a Layer 2 Ethernet switch that performs switching and aggregation of the video streams. Hundreds of these GigE channels are transported over a Fujitsu DWDM network to the s. At the s, the streams are sent to an IP to ASI gateway and then onto standard QAM/RF devices or sent directly to newer GigE QAMs. Once modulated by the QAM/RF, the signal is transmitted across the normal HFC network and into residential homes and set top boxes. HFC Network s Layer 2 Switch Headend 7500 DWDM/GigE Transport 7500 Figure 5: Network 5
The Fujitsu 7500 Platform Optimized GigE Transport Solution Key to the success of any service is cost effective transport of hundreds to thousands of streams over the core MSO network using GigE interfaces. Fujitsu designed the 7500 DWDM platform specifically for MSO applications, including. The high-density Gigabit Ethernet muxponder cards dramatically lower the per-stream costs of networks. The 7500 auto balancing features ensure your network maintains optimal performance, without the cost and thousands of hours of manual adjustments required on other DWDM networks. Widely deployed on several MSO networks, Fujitsu DWDM solutions provide proven performance, leading to superior business results. Benefits include: Reduced Network Costs Offering the lowest cost per stream transport, the 7500 DWDM system boosts bottom line profitability. Revenue Growth Fujitsu DWDM networks offer new revenue-generating services, including, VoIP, Ethernet data services, legacy video services and business services, all across a single core network. Service Delivery Turn up services and wavelengths in minutes instead of the months required on other products. The improved service velocity means new services start generating revenue faster. Reduced Operating Expenses Surprisingly, the largest cost factors for optical networks are not the initial equipment costs but the ongoing expense of operating and maintaining the network. Fujitsu provides advanced self-tuning and power balancing features to eliminate time consuming manual adjustments. Figure 6: 7500 Platform The 7500 Platform Overview The 7500 system is a next-generation metro DWDM platform capable of supporting from 1 to 40 C-band wavelengths.the system is divided into two sections, an all optical OADM and an OLC shelf as shown in Figure 6. MUXPONDER 7 5 0 0 MUXPONDER 40λ C-BAND The all optical switch fabric shown in Figure 7 provides the flexibility to add or drop any of the 40 channels at any node, allowing easy modifications as service patterns change. Because it operates at the optical layer using wavelengths, the 7500 system can support multiple service types on a single platform. Figure 7: All Optical Switch Fabric of the 7500 Platform 6
1 x 2 1 x 2 1 x 2 1 x 2 Fujitsu provides patented optical technology and advanced self-tuning features that eliminate the timeconsuming manual adjustments required on most other DWDM products.the 7500 platform actively monitors the power levels on each of its optical channels, automatically adjusting and tuning itself as wavelengths are added or deleted.this self-tuning feature, illustrated in Figure 8, eliminates the need to send a small army of technicians out to manually adjust power levels and attenuation settings at every node whenever a service is added or deleted. New services can be established in minutes rather than weeks, which means faster revenues and more satisfied customers. REF REF Figure 8: Self-Tuning Automatically Balances Wavelength Power Levels Each service type is supported through an OLC as shown in Figure 9. The OLC provides performance monitoring of the incoming signal, converts the signal to a specific narrowband wavelength, and provides communications to remote equipment for OAM&P purposes. For applications, the GigE card provides eight GigE interface ports multiplexed onto a single wavelength, allowing up to 340 GigE channels per network. 10 Gbps 100 Mbps to 2.5 Gbps 8:1 GigE 4:1 OC-48 Figure 9: OLC Options for the 7500 Platform 7
Elimination of Overlay Networks The 7500 platform further reduces operating costs by eliminating the need for overlay networks as shown in Figure 10. Most MSO networks employ multiple core networks, with each network or layer designed to support a single service, including: Digital.................... DVB-ASI Circuit Switched Telephony...... DS1 CMTS............................ 100Base-TX, GigE, OC-3, OC-12............................. GigE The 7500 platform can collapse all of these services into the single, converged broadband network shown in Figure 11, eliminating the cost to maintain and operate multiple networks and freeing up fiber for additional revenue-bearing services. on Demand Telephony Analog Digital Cable Modem Business Services Digital Cable Modem on Demand Telephony Analog Business Services 7 0 0 0 Local Feed 7 0 0 0 7 0 0 0 Master Headendd Master Headendd Figure 10: The Complexity of Overlay Networks Figure 11: The Simplicity of Multiservice Networks The Possibilities are Infinite In today s business environment, you need a partner you can trust. Fujitsu offers more than 60 years of proven experience and optical networking leadership. As a networking company with more than $38 billion per year in revenue, Fujitsu has the financial stability and technical development resources to ensure an MSO network remains robust and profitable. Our resources are focused toward the single goal of helping MSOs build next-generation networks that offer dramatically lower transport and operating costs, as well as enhanced service flexibility and faster service delivery. This next-generation optical network is here today with Fujitsu Gigabit Ethernet solutions, based on the 7500 DWDM platform. 8
Acronyms Acronym ASI CMTS DVB DWDM GigE HFC IP MOD MPEG MSO OADM OAM&P OLC PVR QAM RF SONET STB S TS VCR VoIP Descriptor Asynchronous Serial Interface Cable Modem Termination System Distribution Hub Digital Broadcast Dense Wavelength Division Multiplexing Gigabit Ethernet Hybrid Fiber Coax Internet Protocol Movies on Demand Moving Pictures Experts Group Multiple System Operator Optical Add/Drop Multiplexer Operation, Administration, Management & Provisioning Optical Line Card Personal Recorder Quadrature Amplitude Modulation Radio Frequency Synchronous Optical NETwork Set Top Box Subscription on Demand Transport Stream Cassette Recorder on Demand Voice over Internet Protocol Copyright 2004 Fujitsu Network Communications Inc. All rights reserved. and (and design) are trademarks of Fujitsu Network Communications Inc. (USA). FUJITSU (and design) and THE POSSIBILITIES ARE INFINITE are trademarks of Fujitsu Limited. All other trademarks are the property of their respective owners. 9