Time Warner delivers full-service video network
Last December, after an intense two-year hardware/soft ware integration effort, Time Warner Cable activated a test trial of an advanced hybrid fiber/coaxial-cable network in suburban Orlando, FL.
A project of Time Warner Entertainment Co. with partners Time Warner Inc., US West, Toshiba Corp. and Itochu Corp., the digital, asynchronous transfer mode-switched, interactive, broadband network is delivering to the first six connected homes such initial services as movies on demand, video games and home-shopping.
Officially designated as the Full Service Network, it merges cable, telephone and computer technologies from a team of leading companies, including AT&T Network Systems, Silicon Graphics Inc., Scientific-Atlanta Inc., Hitachi America Ltd., Toshiba Electronics and Hewlett-Packard Co.
Although the installed network is a viable commercial entity, Tom Feige, president of the Full Service Network, a division of the Time Warner Entertainment Co., refers to it as "the world`s most advanced telecommunications research lab."
As to the financial investments in the full-service network, Jim Chiddix, senior vice president for engineering and technology at Time Warner Cable, states, "The involved companies view Orlando as a research and development project. They all understood that they were not going to get a return on just 4000 customers, but they expect that the knowledge gained is going to be invaluable."
The network partners are also taking developed technologies to other commercial ventures. For example, the software system serving as the cornerstone of the full-service network is being marketed by AT&T and Silicon Graphics via their joint venture known as Interactive Digital Solutions.
Time Warner is closely monitoring how customers value and use the network`s various multimedia services to learn how to price and market different services and applications. It is also helping advertisers discover how they can profitably move into supporting broadband networks by delivering commercial content cost-effectively.
Says Gerald M. Levin, chairman and chief executive at Time Warner Inc., "As we move ahead in Orlando, we are installing the full-service network`s fiber-optic backbone in our cable operations across the country. These upgrades will enable us to offer a wider range of programming choices."
Adds Joseph J. Collins, chairman and chief executive at Time Warner Cable, "We intend to learn from Orlando, refining the technology, pushing down its cost and determining precisely what our customers want. The key is that we have a powerful network upon which we can build a system of services that will evolve over time, but with increasing momentum, as we refine this technology."
Comments Chiddix on the nearly one-year schedule delay, "There have been scores of crises, a variety of highly technical wrinkles, twists or complications that nobody could foresee. We`ve had to solve each of these as methodically and inventively as possible."
According to Bart Stuck, president at Business Strategies LLC, a Westport, CT-based network computing and communications consultancy, "The gating items in deploying the Time Warner full-service network were not photonic; they were largely based on software and system integration issues. The next five years of photonics technology will see higher levels of device reliability and cost reduction. So, the future full-service network issues will not be technology, but rather, increasingly based on business economics."
Chiddix claims this full-service network can be put in place for less than $1000 per user. Of that amount, $200 to $250 is for upgrading the plant with fiber. Time Warner is committed to that amount for fiber-upgrading virtually all its cable systems by the end of 1998. The remaining $750 covers set-top boxes, servers, switches and software.
The fiber aspects
The full-service network implements a fiber-to-the-feeder architecture, where singlemode fiber-optic cables containing six to a few hundred strands are installed from the headend to neighborhood nodes. Several strands serve as spares, and each node handles approximately 500 passed homes. The fiber is supplied by Siecor Corp. and Alcatel Network Systems, among others.
Time Warner has installed approximately 1600 kilometers of optical fiber in the test area and approximately 8000 km in the Orlando network. In 1996, the completed network should total 32,000 km of fiber.
Coaxial cables are used to link the neighborhood nodes to customer homes. The cable`s bandwidth exceeds 1 gigahertz.
To understand how the full-service network works, consider the actions that take place when a customer orders a movie through the home communications terminal and a remote control unit.
On the television set, an on-screen, rotating, Carousel navigation system, co-developed by Silicon Graphics and And Communications, displays venues of services. The customer enters the home video theater venue and chooses a movie. The movie request is forwarded through the cable distribution system and then to a demultiplexer (made by Hitachi), a Globeview 2000 20-gigabit-per-second ATM multimedia packet switch (from AT&T Network Systems) and media servers and storage facilities (supplied by Silicon Graphics). Capable of terabytes of storage, the servers implement eight to 36 processors that each can run millions of instructions per second to choose the requested movie from vaults that store movies as compressed digital video on magnetic hard drives.
Next, the servers place the video data into ATM packets--48 bytes of data and a 5-byte header or address for each packet--and send the packets at optical carrier level 3 speeds (155 megabits per second at 3 to 6 Mbits/sec per video stream) back to the ATM switch.
The switch reads the packets and routes them at digital signal level 3 rates (45 Mbits/sec) as video channels to a quadrature amplitude modulator from Scientific-Atlanta. The modulator device changes the signals into radio-frequency signals. Some of the DS-3s serve as control channel data for each neighborhood node and are demultiplexed to DS-1s (1.544 Mbits/sec).
Both the DS-1s and DS-3s go to a combiner that completes the spectrum by adding the digital frequencies to the analog ones. The signals then arrive at the transmitting lasers, where they are sent through the fiber-optic cables to the neighborhood node. There, the signals are converted to radio-frequency signals and transmitted over coaxial cable to the home communications terminal (jointly developed by Silicon Graphics, Scientific-Atlanta and Toshiba Electronics) located inside the customer`s home. This terminal retrieves the ATM data packets, reassembles them as a data stream, decompresses the video and displays the movie. The entire operation from selection to reception takes less than one second.
The full-service network implements existing communications standards and protocols as applicable. For example, synchronous optical network technology for transport utility is used; such computer protocols as transport control protocol/Internet protocol aid in formatting data streams; and motion picture experts group-1 compression and simple network management protocol are also used. The operating system and application interfaces are new technologies, but they are structured on existing computer formats. These standards promote interoperability as demonstrated by the myriad of participating vendors.
Time Warner expects that 4000 of the 5200 residential subscribers in the Orlando test area will receive advanced services before the end of 1995. These services include local and long-distance telephone access, retail and grocery shopping, online computer, on-demand news, sports, education, entertainment and other products developed by several Time Warner divisions and numerous contents providers. The company also claims that 85% of its cable operations nationwide should be full-service operational by 1998.
Time Warner is supporting the building of flexible and powerful fiber-based full-service networks because they can be quickly and easily adjusted to meet market demands. In fact, should developing technologies emerge more rapidly than expected, they would be incorporated into the Orlando network as soon as possible to deliver enhanced voice, video and data services.
In the full-service network, all the neighborhood nodes are operational, but as yet, not all are operational for digital services. Most nodes are serving customers with analog services. But, according to Chiddix, until Time Warner understands network demand and the capacity strain of the Orlando architecture, there is no reason to push fiber closer to the home. However, with spare fibers in place, the company can go back later and divide the node into two nodes of 250 or less homes.
Economically, says Chiddix, fiber to the home is many years away. It cannot compete in cost and capability with what can be accomplished with a hybrid fiber/coaxial-cable system. To get the flexibility that cable customers desire, a network must offer an array of analog channels for direct access by television tuners. q