Fiber links telecommunications and TV at NAB show
Fiber links telecommunications and TV at NAB show
Growing demand for compressed digital high- and standard-definition Moving Picture Experts Group-2 (MPEG-2) signal transmission is creating alliances between suppliers and common carriers, as demonstrated at the National Association of Broadcasters show (NAB `96) held in Las Vegas last April. This drive for partnerships bodes well for fiber-optic cable, terminal and networking vendors because optical fiber is the common link.
Television industry companies extolled the user benefits of vendor partnering as expected, given the frenetic pace at which standards bodies are researching the need for, and issuing, digital standards for this industry.
In a sweeping endorsement for vendor partnering, five companies--Tektronix, Hewlett-Packard, Avid, Panasonic and Silicon Graphics--are becoming involved in Fibre Channel networking for video applications. These alliances focus on Fibre Channel support based on the companies` commitment to open solutions for broadcast and postproduction industries.
Also evident at the show was the change in marketing philosophy of telephone company common carriers. A few years ago, they considered a 1.5-Mbit/sec bit stream broadband. And, where available, DS-3 services (44.736 Mbits/sec) for television signal transport were tariffed to reflect the loss of telephone-call revenue streams. At NAB `96 Alcatel, Northern Telecom and Pacific Bell showed that DS-3 service can be configured to carry a variety of digitally compressed television-signal traffic, including the following:
seven MPEG-2 main profile/main level (MPML) television channels
one 270-Mbit/sec digital component video channel and four audio channels
one high-definition TV (HDTV) channel
EMC2 Corp., a data storage company in Hopkinton, MA, demonstrated its media server for storing high- and standard-definition programming, which for this debut was externally compressed and delivered to it at 45 Mbits/sec. Booth monitors displayed simultaneous, separate DS-3 playbacks, one of which was up-converted to a "digital cinema" HDTV presentation. Another stream was demultiplexed to provide multiple 1.5-Mbit/sec MPEG-1 feeds to workstations. Simultaneous feeds were carried by catwalk-installed fiber cables to the Alcatel, Northern Telecom and Pacific Bell booths from the EMC2 media server (see Fig. 1).
Alcatel Network Systems, of Richardson, TX, separately announced that it has joined with BellSouth to supply 750 of its Model 1718 video codecs for the 1996 summer Olympic Games in Atlanta. According to Alcatel spokesman Mike Newsom, "Video feeds across fiber from all of the sporting venues are expected to be delivered to the international broadcast center in Atlanta.
"It is likely that at least some of the equipment may be distributed throughout other portions of the BellSouth network following the Olympics," Newsom says. Alcatel`s 1718 video codec takes analog composite signals and provides 149.76-Mbit/sec OC-3c transport for Synchronous Optical Network. The equipment can also be configured to transmit signals over a 140-Mbit/sec Synchronous Digital Hierarchy STM-1 channel for international applications.
Alcatel also demonstrated its latest version of the 1743 video codec. This unit compresses and encodes either analog composite or serial digital component video for real-time transmission over fiber-optic networks at 45 Mbits/sec. Alcatel says the codec meets motion picture and postproduction requirements for transmitting movies and special effects. Alcatel and Miranda Technologies, of St. Laurent, QC, Canada, plan to create an end-to-end system for transporting 270-Mbit/sec digital component signals on DS-3 fiber-optic cables terminated in Alcatel`s 1743 video codecs.
Another partnership pairs the HD2100 downconverter and the HD5100 upconverter of Snell & Wilcox, of Petersfield, Hampshire, UK, with the Alcatel 1743 video codec. This end-to-end system compresses, encodes, transmits and decodes 270-Mbit/sec serial digital component video as well as analog composite video compliant with both U.S. NTSC and European PAL broadcasting standards. A HD2100 downconverter at the front end adds digital, HDTV-signal compatibility to the fiber-transmission system. On the receiving end, the 1743 codec transcodes the DS-3 signal back to 270 Mbits/sec. The HD5100 controls all aspects of the upconversion process. It accepts conventional broadcast-standard signals and provides outputs in all 1050-, 1125- and 1250-line interlaced HDTV standards, as well as 525 and 625 progressive scan.
Another major broadcast supplier, Northern Telecom, of Mississauga, ON, Canada, has an installed base of seven thousand DV45 codecs under end-user control for high-speed digital transmission services. However, as soon as the Advanced Television Systems Committee`s advanced-TV emission standard recommendation is adopted by the Federal Communications Commission, the demand for digital television signal transportation is expected to be at MPEG-2 MP/ML rates: 6 Mbits/sec for standard-definition signals and 20 Mbits/sec for high-definition signals (see Fig. 2).
Nuko Information Systems, San Jose, CA, is an 18-month-old entrant into the MPEG-2 arena, which already includes more than 20 encoder/decoder systems developers. The company debuted two DV-MPEG-2 modules--designed around IBM`s MPEG-2 chipset--that plug into DS-2 slots on the Northern Telecom DV45 platform.
According to Ian Craig, president of broadband networks at Northern Telecom, "Working with Nuko has allowed us to build on our DV45 codecs by delivering bandwidth- efficient deployment capabilities."
Pacific Bell`s Bob Stewart called the Northern Telecom/Nuko product line expansion a "telephone company solution." He added, "This gives us economic advantages to pass on to our cost-conscious customers. DS-3 single-stream transmission is too high priced; [Asynchronous Tranfer Mode] is even higher. At the `mass market` pricing we can now offer, [one of our major distance-learning customers] plans to increase its five channels of simultaneous course offerings to 28, accessible at 175 sites within California."
In another NAB `96 development, CableRep Advertising, the cable-TV advertising arm of Cox Communications Inc., in Atlanta, has agreed to purchase fiber-optic equipment and DV-MPEG-2 digital codecs from Northern Telecom to bring selected video content to and from its master control site in Phoenix. q
Bob Paulson is founder of Omnimedia Communication in Westborough, MA, and an industry consultant.