|
|
|
Solutions » Cable Operators Cable operators have a unique asset, when compared to their satellite and telco competitors—550+ megahertz of node-based, two-way-enabled plant. The transition to all-digital video transmission will enhance the value and utility of this investment: better quality picture, better bandwidth efficiency, and the ability to leverage the developments and economies of scale of modern “data” networking. Cable will have the advantage of an affordable, flexible, ubiquitous high-capacity channel to and from every home and every pair of eyes. The cable industry has already made a massive investment in CATV plant upgrades over the last decade, so it is imperative that the conversion to all-digital incur minimal incremental cost, while remaining flexible enough to support the advanced services enabled by an all-digital, two-way plant. The RetroVue® System encompasses a suite of crucial components, comprising a high-density broadcast/switched-broadcast/narrowcast edgeQAM, a high ingestion rate video server, an ASI-to-Gigabit Ethernet IP streamer, a CMTS-bypass controller, and a controller/set-top application server. How does RetroVue work?GoBackTV’s suite of products supports the RetroVue service by enabling compact, affordable narrowcast video, as well as digital broadcast. The RetroVue service works by allocating each viewer his own, personal television channel, which means that he gets to watch what he wants, not what everyone else is watching. Besides jumping back to the start of the program, the viewer can jump forward, jump backward, pause, and return to the normal video broadcast. Also, by using the MyRetroVue™ interface on his set top, computer, or PDA, the subscriber can create play lists, manage channel bundles, specify advertising preferences, and access other time-shifted, on-demand applications, such as network PVR (nPVR), Video on Demand (VoD), and Television on Demand (ToD). In addition, the MSO can use the two-way interaction to enforce and augment Digital Rights Management (DRM) and Conditional Access policies. Enabling technology GoBackTV’s vision reflects the new digital headend, in which video, voice, and data services coalesce into a single digital system. RetroVue delivers the video portion of this all-digital triple play. Individual components interconnect through standardized Gigabit Ethernet (GbE), and can be deployed to fit any cable operator’s network topology—centralized, distributed, redundant, or mixed. RetroVue system elements can interoperate with legacy and third-party equipment. They can also perform as standalone products.
Figure 1 RetroVue System Diagram (Distributed Architecture)
Figure 1 illustrates the RetroVue system. GoBackTV-supplied elements include:
GigaQAM edgeQAM. GigaQAM enables narrowcast, broadcast, and switched broadcast transmission in a single compact package. The GigaQAM 3000 also supports packet encapsulation for IPTV-over-cable using CMTS-bypass technology. All versions of the GigaQAM provide 24 QAM-RF outputs, integrated with an extremely versatile software-based multiplexer and optional conditional access scrambling in a 1RU chassis. Channels are dual-bonded but otherwise completely frequency agile. Inputs are three Gigabit Ethernet RJ45 ports, which are used for video input, dual-homing, and management. GigaQAM IP CMTS-bypass controller. The
GigaQAM IP enables affordable delivery of IPTV over cable, using
existing standards-based DOCSIS® 1.1 and 2.0 cable modems and
low-cost IP set-top boxes. The GigaQAM IP provides DOCSIS timing
and control information for up to eight attached GigaQAM 3000 edgeQAMs
(192 QAM channels), allowing the edgeQAMs to deliver any mix of DOCSIS
and traditional MPEG2 video, even within a single channel. It
also provides up to six upstream channels to be shared among the
downstreams. StreamCache high-ingestion-rate video server. StreamCache is a 2RU server which currently provides up to 1700 hours of real-time storage at 3.8Mbps, and sufficient disk throughput to ingest 100 simultaneous digital channels and serve 480 independent, non-blocking 3.8Mbps video streams. I/O and management ports are Gigabit Ethernet. RetroVue Application Server. The RetroVue Application Server is the heart of the RetroVue System, and coordinates RetroVue System components to deliver a complete spectrum of stream-based video services, including switched broadcast, Video on Demand (VoD), network PVR (nPVR), time-shifted television, Start Over and Look Back, historical EPG, user-based profiles, and personalTV services. It manages and controls the entire RetroVue system, including service creation, subscriber management, dynamic scheduling of video streams and edgeQAM resources, system monitoring and data collection, and GUI-based element management and configuration. The platform also provides host support for MyRV Portal HTML-based middleware, which enables television service providers to deliver customized navigation and information services to subscribers’ set-top boxes using a standard HTML browser interface. By leveraging industry standards, client GUI layout and appearance are simple to customize or update, and can even be done in-house using standard design tools. DVB-SIfter. The SIfter is used to probe the DVB System Information (SI) tables embedded within DVB-C transmissions and extract Electronic Program Guide (EPG) information for the RetroVue Application Server databases. With this information, the RetroVue Application Server creates a historical EPG to help viewers locate and navigate time-shifted content. The input port for the SIfter is Gigabit Ethernet. ASI-to-Gigabit Ethernet IP Streamer. The AG4404 converts up to 4 ASI’s worth of MPEG-2 transport streams into a Gigabit Ethernet stream in order to bridge the gap between legacy interfaces and RetroVue components. The output stream can be unicast or multicast IP or native Ethernet. Input Multi-Program Transport Streams (MPTSs) may be transmitted in “pass-through” mode or may be demultiplexed into individual Single Program Transport Streams (SPTSs) for simpler remultiplexing or for transmission to separate destinations. In addition, the ASI-GbE IP Streamer can perform the same function as the SIfter, and provide DVB-SI-based EPG information to the RetroVue Application Server. How to get started with RetroVue?RetroVue System components can be deployed as standalone elements to deliver just the functionality you need, when you need it. For example, GigaQAM can be deployed alone as a broadcast QAM gateway during a cable operator’s analog-to-digital transition, to carry a simulcast digitized version of the analog channel lineup. Once the migration is accomplished, analog channels can be recovered, and the newly-freed bandwidth repurposed for stream-based services such as switched broadcast , time-shifting, VoD, and nPVR by adding GigaQAMs, StreamCaches, and RetroVue Application Servers. In addition, the QAM channels can deliver IPTV through DOCSIS 1.1/2.0 cable modems with the addition of a GigaQAM IP CMTS-bypass controller. As the demand for personal streams increases, the RetroVue system can be incrementally expanded. Half a rack (20RU) of RetroVue head end components can service 2000 independent MPEG-2 video streams, including real-time ingestion of 100 channels of digital video, play-out of 2000 streams, remultiplexing, timing correction, conditional access encryption, stream processing, and 64/256 QAM-RF synthesis, all at a fraction of today’s VoD per-stream costs. How does RetroVue fit in the cable plant?
> Figure 2 RetroVue connections in the head end
Digital video sources with traditional ASI interfaces, such as IRD/IRTs, encoders, remultiplexers, and video groomers can feed into an ASI-to-GbE converter for protocol conversion to Gigabit Ethernet. The newest generation of video sources now includes Gigabit Ethernet output options as well. StreamCache can intercept video streams carried on Gigabit Ethernet to provide storage and play-out for on-demand services, or can be bypassed by legacy VoD and non-stored video. GigaQAM accepts video input on Gigabit Ethernet, and outputs QAM-RF into the plant’s combining network. The GigaQAM IP CMTS-bypass controller enables the GigaQAM to use any or all of its channels to carry IP traffic as well. GoBackTV equipment can accept native Gigabit Ethernet input, or IP/UDP-encapsulated Gigabit Ethernet, with either multicast or unicast addressing. Content may be pre-encrypted by Conditional Access systems, or it may be encrypted by GigaQAM on the fly using DVB Simulcrypt, 3DES, or AES. Although diagrams in this document show all components, each RetroVue product may be used independently from the others. Spectrum usageDuring initial rollout, GigaQAM can be used to modulate as few as one or two 6Mhz or 8MHz channels on any given trunk. This allows GigaQAM-supported services to be installed in parallel with legacy services. Figure 3 illustrates this situation.
<> Figure 3 Spectrum usage during the transition
In an all-digital, all-switched broadcast future, RetroVue can be used to provide every television set in a node with its own unicast channel, enabling unlimited services. Cable operators could offer their subscribers many more channels and services than today’s 550MHz and 750MHz plants can carry, since each television can only watch one channel at a time. A node size of 500 households passed could be served at 100% penetration, 100% peak usage, and more than two televisions per house. Figure 4 illustrates this case.
Figure 4 Spectrum usage in a switched broadcast mode
Conclusion RetroVue takes television viewing
into the future. It co-exists with existing digital services; it
enables added-value services that generate new cash flows; and it gives
a competitive advantage in the battle to gain new digital subscribers,
regain lost subscribers, and retain existing subscribers. RetroVue System Overview (cable/pdf) RetroVue System Datasheet (cable/pdf)
|
