Path: utzoo!telecom-request Date: Mon, 13 May 1991 21:23:26 GMT From: Bud Couch Newsgroups: comp.dcom.telecom Subject: Re: Hayes Wins Damages on its Command Set Patent Message-ID: Organization: Kentrox Industries, Inc. Sender: Telecom@eecs.nwu.edu Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 11, Issue 355, Message 6 of 9 Lines: 46 In article 0004133373@mcimail.com (Donald E. Kimberlin) writes: > The "Hayes AT Command Set," a defacto standard used by > virtually every dial-up modem for more than a decade, has had some of > its functions patent protected, but that has not kept it from being > virtually freely used. Perhaps Hayes has kept a low profile on the > matter, preferring to let its name be spread by such wide use. In the interest of stemming panic out there, let's be quite clear. The enforcement was to a specific patent, not to the "Hayes AT Command Set". That patent, although quite important to modem users, does not cover the "AT" _command_ set. As a matter of fact, as PN-2120, a document from TIA committee TR-30.4, the command set has been submitted to the CCITT as part of draft recomendation "V.25 ter". One of the regular contributors to TELECOM Digest, Toby Nixon of Hayes is the chairman of TR-30.4, and can probably post an update of the status of this proposal, if asked. Communication software writers can, quite freely, write software which sends the string "AT whatever" and DCE equipment may recognize that string and act upon it. The patent upheld is on the method of notifying the DCE equipment that the next data arriving should be treated as a command to the DCE, as opposed to data to be transmitted to the far end; that is, switching to command mode. Most software defaults to a one second pause, transmitting three plus (+) signs, followed by a one second pause. Hayes patent is broader, covering any time delay, followed by any unique sequence. This patent, however, covers only async data ports used for both data and command. Synchronous ports, obviously, cannot pause in sending data, and the use of separate command and data ports is also outside the scope of the patent. For those in the external async modem business, the Hayes patent is a business expense that they will have to factor in. The rest of us can continue to type in "ATxxx" without worrying that the feds are going to come after us. Bud Couch - ADC/Kentrox standard BS applies