CCITT COMMITTEE MEMBERS CALL FOR STANDARDIZED APPROACH Challenge Vendor For Co-Opting 28.8 Kbps Standard SKOKIE, Ill., -- June 8, 1992 --Two members of the Consultative Committee on International Telephony and Telegraphy (CCITT) have challenged the recent introduction of a modem by Motorola Codex that Motorola Codex claims conforms to the developing CCITT standard for 28.8 Kbps dial-up communication. The standard is known in its working form as "V.Fast," a nickname Motorola Codex borrowed for its 326XFAST modem. But with the CCITT study group at least a year from agreeing on a standard, and the standard itself not expected to be officially adopted until 1994, any claims of conformance are dubious, according to the committee members. "Most of the fundamental things haven't even been agreed on yet," said Dick Stuart, chairman of the CCITT committee developing the 28.8 Kbps standard and technology vice president of Penril Datacomm Networks, Gaithersburg, Md. "I've had people suggest to me that we change the preliminary name for the standard (V.Fast) just because of what has happened. Some people have even asked me if we can have a number assigned to the standard, whereas normally that's one of the last things we do." Dale Walsh, vice president for advanced development at U.S. Robotics, Inc., says the Motorola Codex modem incorporates some early proposals that the company made to the CCITT committee. "But it doesn't conform to the standard we are working on," Walsh said. "Nobody can make that claim yet." Stuart said that Motorola Codex's move creates confusion for customers and could delay work on the standard. "Now it becomes more of an issue of turf protection for the committee, rather than trying to get the best recommendation for all concerned," he said. "It' s tough for a body to come to an agreement when maybe what they'd be agreeing on has already been done by one manufacturer." Jonathan Zakin, executive vice president of sales and marketing at U.S. Robotics, noted that while Motorola Codex promises an upgrade path when the 28.8 Kbps dial-up standard is adopted, USR is the only firm offering a field upgrade. The company will offer users the opportunity to purchase an easily installed daughterboard that will plug in to existing USR modems, thus allowing an upgrade to the CCITT standard when it is finalized. "Nobody knows what the standard for '28.8' will be, but we do know what the maximum hardware upgrade will be," said Zakin. "So while we won't say that our modems conform to the 28.8 standard, we can say that our modular architecture provides a clear upgrade path to whatever that standard will be. And it's something a user can install in 10 minutes -- which means they won't be without their modem while it's at some factory being upgraded." -------------------------------------------------------- CCITT 28.8 Kbps STANDARD: BACKGROUNDER SKOKIE, Ill., -- June 8, 1992 --The standard for 28.8 Kbps dial-up communications being developed by the CCITT will stretch the limits of dial-up telephone lines. But don't expect to be sending files at top speeds immediately. Dale Walsh, vice president for advanced development at U.S. Robotics, Inc., cautions that most users won't be able to achieve the maximum speeds permitted under the standard right away. When the standard is adopted, modems that conform should be able to transmit at 19.2 Kbps on lines where a modem conforming to V.3bis (the current high-speed standard) can now transmit at 14.4 Kbps. But Walsh, a member of the CCITT committee developing the standard, says it is being formulated with the increasing digitization of dial-up phone networks in mind. "The improved quality of phone lines, as much as any modem technology improvements, has made high-speed dial-up communications possible," says Walsh. "We are designing the standard keeping in mind that phone networks will use more and more digital circuits and digital central office switches." Consequently, speeds in the neighborhood of 28.8 Kbps will be the exception, rather than the rule --at least until the public switched telephone network becomes completely digital. "I'd say that when it's finished in a year or so, the standard will allow 19.2 Kbps transmissions on about 80 percent of all lines, 24 Kbps on 50 percent of all lines, and 28.8 Kbps communications on 20 percent of all lines," says Walsh, who also helped develop the CCITT V.32bis standard for 14.4 Kbps dial-up communications. "As the phone networks improve, top speeds will be more easily achieved, so I think it's more realistic to think of it as a 19.2 Kbps standard that is sometimes capable of higher speeds." A common misconception is that the coming 28.8 Kbps standard will allow speeds of 115.2 Kbps, when combined with V.42bis data compression. Walsh noted that such calculations are based on an assumption that V.42bis allows 4-to-1 data compression. Outside the lab, V.4bis allows compression ratios between 2-to-1 and 3-to-1 meaning that under real-life conditions, the forthcoming standard will allow maximum throughput of about 86.4 Kbps. "It's a mistake to use the 28.8 number and max everything out from that," said Walsh. Not that the 28.8Kbps standard doesn't have its advantages. After all, 19.2 Kbps is an improvement over 14.4 Kbps. And the forthcoming standard will adjust for line conditions -- a critical factor in high-speed data communications -- like no previous standard. The standard under development will include a "probing" function that the modem can use to "sound out" the quality of the phone line. That will allow the modem to optimize transmissions to take advantage of available bandwidth. "We are still working on the training sequences," says Walsh. "But before transmission starts, the standard will enable the modem to determine what bandwidth is available and how to best position the signal to match available bandwidth." The standard achieves higher speeds through its ability to use more of a line' s bandwidth -- not just the center portion of the channel used under current standards. "It will more closely match the modulation scheme to what's available," says Walsh. "That way, the modem can shape the transmission to adapt precisely to the channel -- which is very important if you want to transmit at high speeds." The most recent committee meeting was held last week. Still to be agreed upon are such critical issues as training sequences, coding schemes and signaling rates. Walsh said he expects the committee to reach final agreement in 1993, with official CCITT adoption likely in 1994. While some have taken to calling the standard under development V.Last, Walsh isn't convinced this will be the final modem standard. After all, he notes, no one thought dial-up phone lines would ever be this noise-free, and further advances in that area could make even higher speed dialup communication possible. "I'm certain we'll have at least a fax version of this standard as the quality of phone lines keep improving," he said. "We're trying to be sure that this standard will serve users into the year 2000. But modem standards are like wars -- you always think it's going to be the last one." U. S. Robotics, Inc., (NASDAQ: USRX) is a worldwide designer, manufacturer and marketer of data communications hardware and software. U.S. Robotics' product lines include Shared Access resource-sharing products for remote LAN access, the Total Control modem management system and network access servers for central data sites, BLAST software products for terminal emulation, file transfer and remote control, Courier data and fax/data modems for corporate users, WorldPort portable data and fax/data modems for traveling professionals, and Sportster data and fax/data modems for small business, home office and entry-level users. Both corporate headquarters and manufacturing operations are based in Skokie, Ill. U.S. Robotics owns and operates Miracom Technology Ltd., Slough, England and U.S. Robotics, s.a., Lille, France. The company markets its products to business, industry, government agencies and original equipment manufacturers. U.S. Robotics, 8100 North McCormick Blvd, Skokie, IL 60076 708-982-5010 800-DIAL-USR +---------------------------------------------------------------+ | From the America Online New Product Information Services | +===============================================================+ | This information was processed with OmniPage Professional OCR | | software (from Caere Corp) & a Canon IX-30 scanner from data | | provided by the above mentioned company. For additional info, | | contact the company at the address or phone# indicated above. | | All submissions for this service should be addressed to | | BAKER ENTERPRISES, 20 Ferro Drive, Sewell, NJ 08080 U.S.A. | +---------------------------------------------------------------+