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T.30
T.30 is a Group III/IV-compatible standard for routing faxes to users via subaddresses or fax mailboxes. Message security is included, with only the cover page capable of being viewed. The routing can be accomplished in several ways, including DTMF, DID, OCR, and manual. Dual Tone MultiFrequency (DTMF) routing requires the sender to enter the appropriate fax extension via a telephone tonepad. Direct Inward Dialing (DID) routing requires a PBX and each fax extension is required to have a separate DID number. Optical Character Recognition (OCR) software, lets the server recognize the name or special identification of the intended recipient. OCR currently is more expensive and less reliable than are the other options. Manual routing is the most common approach, with an individual viewing only the cover page and then routing the fax as appropriate.
In a client/server computing environment, each LAN-connected client workstation is assigned a fax extension number. Inbound fax messages received by the fax server are then automatically routed to the appropriate workstation associated with the intended recipient. Through entry of the appropriate security password, the recipient then accesses the facsimile message. Assuming that the message is T.434-compliant, it can be edited and annotated by the recipient prior to either a fax response or forwarding to a user-definable distribution list. Companies such as Brooktrout have developed software that allows the server to recognize the dialed telephone number with the trailing subaddress. The fax can then be routed to a fax machine, another client workstation, or an e-mail address. Server software developed by companies such as Castelle enable the server automatically to determine whether to send the message via the PSTN or e-mail [5-10].
Rather than being replaced by e-mail and other forms of messaging technology, facsimile appears to have a long and prosperous future. Dependable, inexpensive, standardized and virtually ubiquitous, fax promises to continue its role as a valuable communications tool. While e-mail offers a number of advantages over fax, it is not widely available in developing countries. Further, facsimile is an inexpensive and highly-effective complement to other messaging systems.
As costs continue to drop and as PCs equipped with fax boards and software become more common, fax will penetrate virtually every small business and household. Fax servers will become commonplace in medium and large businesses. Fax-on-Demand (FOD) will challenge direct mail and will become used extensively in fulfillment of information requests generated by various, more traditional, forms of advertising.
Mobile fax will become commonplace, as more laptop computers are equipped with fax modems in the form of PCMCIA (Personal Computer Memory Card Industry Association) cards, also known as PC cards. The questionable trend toward PDAs (Personal Digital Assistants) may encourage mobile fax, as well [5-11] and [5-12].
Color fax is accomplished either by standalone color fax machines, special fax compression techniques, or computer fax techniques. Color fax machines, which began to appear commercially in 1995, will increase in popularity as dependable and affordable multifunction devices are developed. Such devices will take the form of combined faxes/printers/scanners/copiers. The technology exists today through interfaces between computers and color copiers, but is relatively expensive and non-standardized; as a result, its application is unusual. An exception is Windows 95 Color Link from Laser Today International. Priced at US$138 and residing on a Microsoft Windows 95 or Apple Macintosh platform with fax modem, the software allows the transmission and receipt of color faxes between similarly equipped computers.
Fax compression technology, through the use of special software, will become more common. InfoImaging Technologies, for instance, has developed 3D Fax Software which will compress any file at 100:1. The proprietary software, which must reside on both transmitter and receiver at a current cost of US$100-$200, can transmit up to 1 GByte (1GB) of data in 99 pages of dot patterns which are decompressed by the receiving system to yield the image in its original form. The faxed information (text, image, video or multimedia files or computer programs) also can be sent to a standard fax machine and then scanned into a computer where the software will act on it to restore the information to its native form. In this manner, a color photograph can be sent via a standard black and white fax machine, scanned into the computer and restored to its original color form [5-13]. Fax compression is becoming increasingly important as the average Fortune 500 company spends an average of US$13.6 million on fax-related network usage40% of a companys total long distance bill according to a 1995 Gallup/Pitney Bowes Fax Usage and Application Study. Due to differences in time zones, that figure goes up to as much as 75% for many companies doing business in Asia [5-14].
Major international carriers (AT&T, MCI, and Sprint) recently have developed various fax network offerings. AT&T offers International Advanced Fax which operates over high-quality digital circuits in the U.S. and to a small number of other countries. For a small set-up charge and monthly minimum, quality is improved and transmission time is reduced. Special rates are available for short-duration calls. MCI and Sprint have developed network-based FOD and fax store-and-forward systems [5-14] and [5-15].
Voice processing systems were developed and deployed on a closed trial (alpha test) basis in the early 1970s as a replacement for answering machines. In the United States, the AT&T Bell Operating Companies (BOCs) trialed CO-based systems. However, the impending MFJ forestalled their commercial deployment, as they were considered to be enhanced services, which the RBOCs were prohibited from offering.
The first commercial voice processing system was developed and marketed by VMX (since merged with Octel) around 1978. That system was a standalone voice mail system with an interface to the PBX, from which the call was forwarded in the event of a busy or no answer condition at the user station. Since that time, a number of manufacturers have entered the voice processing business, and the nature of the systems has changed considerably to include increased feature content, integrated messaging, PC platforms, application development toolkits, and networking.
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