November 11, 1996

http://www.faxworldcom.com

Introduction:

Facsimile technology has come a long way since its beginning. Most people do not realize that the first facsimile machine was actually developed in the 1840’s! These first crude machines have developed into the devices we now use in our everyday lives. The fax machine has gone from a novelty in the early eighties, to a must have piece of office equipment in the nineties. The future will bring us more integration of facsimile machine and computer like features into new machines that will revolutionize the industry.

The core of facsimile technology is of course, the fax machine. This paper will explore the recent past, present, and future of the stand alone fax machine. Technology, however, will not stop there. We will also talk about the current and future trends in multifunctional fax machines, fax servers, fax-on-demand, fax broadcasting, and the recently hyped fax on the Internet. All of these items make up the facsimile systems we know today and expect for our near future.

The stand alone fax machine first really took hold in the mid eighties as the Group 3 fax standard (G3) was introduced. This standard was developed by the former CCITT ( Consultative Committee on International Telephony and Telegraphy) now known as the ITU ( International Telecommunications Union). This standard covered machines that could send a page in less than one minute.

The secret to breaking the one minute barrier was in digital compression of the data to be sent. G3 parameters specified that a compliant machine must have Modified Huffman (MH) compression capability. This allows the fax machines to compress the actual amount of data to be sent therefore reducing the time required to send a page of data.

It is important to note that the phrase "page" is used very commonly when describing a fax machine. References are made as to how fast a given fax machine can send or scan a page of data, how many pages of memory a machine has, or even how many pages it can print before it runs out of toner. In fax lingo a "page" is the CCITT test chart #1 also known as the Slerexe Letter (see Appendix 1). This page has 4% coverage, meaning only 4% of the page is black and the rest is white. A page with double the coverage, as is most often found in business environments today, will take almost twice as long to send.

Now that the word compression and page are understood, how long it actually takes to send a page should be discussed. Under G3 using MH compression, a 4800 Bit Per Second (bps) modem could transmit a page in 60 seconds. The actual transmission takes a little longer because the sending and receiving machines must perform a "handshake". The handshake is where the machines figure out what speed and compression they will use to proceed with the data communication. The V.29 (up to 9600 bps) and V.17 fax standard for modems up to 14400 bps take 16 seconds to perform the handshake. Now the realistic time to transmit our page at 4800 bps is 16 seconds for handshake plus 60 seconds for data for a total of 76 seconds. A modem at 9600 bps could cut the data transmission time in half but have no effect on the handshake. Similar to the handshake is retraining. Retraining is the time between pages of data where the machines verify that the page was transmitted successfully and that the receiver is ready for the next page. This retraining accounts for 4 seconds between every page sent for modem rates up to 14000 bps.

As can be seen, increasing the modem speed does decrease the transmit time but not on a linear scale. This is because the handshake and retraining times are fixed and only the page data moves faster. Up until only recently, modem speeds were essentially at a standstill and another method of sending faxes faster was needed. The answer was better compression.

While MH compression was part of the G3 standard, two other compression schemes were alternately supported. These are Modified Read (MR) and Modified Modified Read (MMR). Using MMR compression, a page of data can be sent at 14.4 Kbps in only 6 seconds whereas the very same modem using MH would take 20 seconds! This is huge speed improvement considering the modem speed remained constant. Inexpensive fax machines and fax boards for computers typically use only MH compression and cost the user big bucks in telephone charges whereas a more expensive machine or fax board will support all compression methods and save a considerable amount of time on the telephone line. This not only reduces cost but also improves the throughput of the machine making it a more effective tool.

As can be seen in figure 1, the combination effect of better compression and higher modem speed combine to provide a very positive effect. Notice that the 14.4 Kbps modem using only MH is actually slower than the 9.6 Kbps modem using MMR! This once again is where the price shoppers fall victim to modem speed without even looking at compression. This is the reason why a 14.4 Kbps modem for a computer can range from $59.00 to $999.00.

Figure 1.

Notice that figure 1 also shows a modem speed of 21.6 Kbps. This is part of the new V.34 standard being introduced for fax. The actual modem speed is as high as 33.6 Kbps, however, real world testing has shown that these modems typically connect at 21.6 Kbps due to noise or echo on the phone lines and only reached 33.6 Kbps 4% of the time in laboratory tests! The V.34 protocol also shortens the time required for handshake and retraining as well as offering a new compression called Joint Binary Imaging Group (JBIG).

This overview of fax communication in basic fax machines provides a foundation to understand additional developments outside of speed of communication.

Multifunctional Plain Paper Fax (MPPF) machines are really no different than the older fax technology with the exception of their print media and additional features. MPPF’s print out on regular paper just like you put in a laser printer or a copier. The preferred print method for medium and large sized offices is laser because it is the most heavy duty of the printing methods and fairly economical compared to the other methods. MPPF’s save the user time since copies of the received pages do not have to be copied at the copier for long term storage thus saving thousands of dollars in additional use of the copier and employee labor.

MPPF’s also have another unique feature, they are multifunctional. This means that the same device one uses to fax can also perform another very important feature such as laser printing, copying or scanning. Some machines offer an RS-232 connection to connect directly to a computers COM port. Others offer connectivity through a parallel port just like a regular printer would have, and some high end machines connect via a SCSI connector.

Of the types of connections listed, those attaching to the parallel port or SCSI connector offer the most preferred method of connecting to a computer. The COM port connection usually is a problem because most computers sold today are already using all of their available COM ports for mouse and modem connections.

The printing feature is one of the most used multifunctional features. On a laser fax machine, an adapter that emulates a common laser printer is attached and you essentially have a high speed laser printer. These options are designed specifically for certain models so be sure the fax machine you may be looking at supports this option.

Using the modem contained in the fax machine from your computer is offered by some vendors but unfortunately has not yet reached a practical point. The problems are that the computer typically is unavailable for use while it is talking to the modem in the fax machine thus creating productivity problems. Also, fax modems in fax machines cannot be used as regular data modems, usually requiring the user to separately purchase a data modem. This is not a very effective use of this device as usually a data modem also supports the fax protocols.

Scanning from the fax machine to the computer is the third and final function of some MPPF devices. While this is practical for low volume and low resolution scanning, it does not address high speed high resolution nor color scanning. The inherent problems are that a fax machine scanner at best can scan 400 DPI while most scanners on the market at the $500 price point are 1600 DPI and color.

To be released in the 4^th quarter of ‘96, several multifunction fax machines at the upper end of the market will have Network Interface Cards (NIC’s) installed in them making them another addressable node on a LAN. This will greatly improve their multifunctional capabilities. These devices will be accessed just like a remote printer or a fax server on a LAN. The true test will come shortly as these devices are installed on corporate LAN’s and their true performance can be evaluated.

As can be seen, the multifunctional fax today is in its infancy. The soon to be released products coupled with connection methods will determine the future of the multifunctional devices. To work properly and efficiently these devices will, however, carry a heavy price tag. When used within their boundaries they should provide effective multifunctional benefits and be well worth their investment in increased efficiency.

Group 4 (G4) fax, also known as digital fax, has also been around since the late eighties. G4 fax encompasses sending facsimile communication over digital networks. The first form of G4 fax was sending over X.25 networks. The G4 machine was assigned an address and data was delivered over the network between G4 machines. This has obvious potential for larger companies communicating overseas where line charges accumulate quickly. Unfortunately, this concept never caught on big and the speed these machines communicated at was typically only 19.2 Kbps.

Another form of G4 fax communication supported is fax communication over ISDN (Integrated Services Digital Network). ISDN fax supports up to 64 Kbps over the ISDN digital network. These machines have phone numbers like regular faxes and can be connected to the increasingly popular ISDN lines offered by the local exchange carriers.

A major benefit of ISDN G4 fax is that handshaking between the machines is extremely fast and actually takes place on a separate line. When ISDN machines connect, its all business. Tests conducted by Faxworld have shown that a 5 page Slerexe Letter takes just 8 seconds to send! This is very favorable to even the very latest in analog fax technology described earlier.

Figure 2

The standard ISDN line that can be brought into the home or office is the Basic Rate Interface (BRI). This service, while traveling over regular twisted pair wire, delivers three channels. A BRI consists of two B-channels each capable of 64Kbps and a single D-channel capable of 16Kbps as shown in figure 2. One of the B channels is used by the G4 fax machine to send and receive data while the D channel is used for call signaling and set-up. ISDN lines are almost immune to static as digital rather than analog signaling is used. The fax received on a G4 fax will typically appear a little cleaner and sharper than one sent on a G3 machine because of this digital signaling.

About the only drawback to ISDN G4 fax is the extremely small installed base of machines. This is partly due to expense of the equipment, and until recently, the difficulty in obtaining ISDN lines. As Internet users find ISDN a more attractive method to connect to the Internet, ISDN fax will stand a good chance of being included as part of the ISDN solution being installed in offices around the country.

A fax server is a computer based fax solution. Essentially a fax server allows all users on a LAN to send and receive faxes from their desktop without having to go to the fax machine. All documents created at the computer can be faxed utilizing the fax server. The resources required such as phone lines and fax boards are contained in the network fax server and are shared resources eliminating the need for every desktop computer to have a fax modem and telephone line. This reduces the costs of faxing by minimizing unproductive time spent walking to the fax machine, waiting for a fax to send, as well as reduces the number of documents printed because they can simply be faxed from the screen with no hard copy being needed. Other major benefits include the ability to attach product brochures or technical information from an available library of your company's documents to accompany your fax.

This a very valuable asset to those companies operating Sales and Technical / Customer Support Centers as it allows the Sales / Customer Service Rep to remain in contact with the customer while the information is being sent. Inbound routing can also be established such that Direct Inward Dial (DID) lines can be utilized to route inbound faxes to the desktop of the individual or department without having to print them.

The fax modems used in fax servers vary widely depending on the quality of the system. At the low end, single line fax boards are used. These fax modems typically are 14.4 Kbps with only MH compression. These modems also place very high demands on the CPU of the fax server as they have no onboard controllers. At the other end of the spectrum there are single cards that contain 12 fax modems each with their own CPU so as to free the CPU of the server for other tasks. These high end modems operate at 14.4 Kbps or greater as well as support all current compression methods.

It is worth noting that recently voice interfaces have been added to specialized fax servers to connect these items to a company's PBX. The voice features allow incoming faxes to be stored in a persons mail box much like voice mail. These faxes can be remotely retrieved by the recipient or forwarded to a destination of their choice. Essentially, fax services are added to the PBX much like voice mail services are added.

Fax broadcasting involves the sending of the same information, such as a technical alert, a promotional special, even the company newsletter to hundreds or thousands of locations automatically. This is available on fax machines but is very limited. A fax machine generally must be programmed with the numbers to send to, typically limited to 200 or less, and can then send the document one after the other over a single phone line. This is extremely slow and ties up the fax machine for long periods of time.

High Volume Fax Broadcasting systems eliminate the bottlenecks of the single phone line and small maximum location limitation. A database of hundreds, thousands, even tens of thousands of fax numbers can be loaded along with several pages to be faxed out. The systems can have as few a one but typically 4 or more fax ports sending information simultaneously. Full T1 based systems can be implemented for extreme needs. This is a very cost effective alternative to mailings that are costly not only in postage, but also in paper, envelopes, printing, folding, labor and timeliness.

Fax broadcasting can typically be done from a good quality multiline fax server. In some instances, however, a dedicated fax broadcaster is required as demand is very high or timeliness of delivery is very critical.

Fax-On Demand (FOD) is an ever increasing method of servicing customers needs for information. FOD is essentially a system that allows customers to call into an automated system, request information either by a document number or voice prompts, and have it faxed to them 24 hours per day. These systems have been used the longest in Technical Support applications to give the user access to information even when the Tech Support Department is closed. Recently, companies have been providing brochures, advertisements, technical specs, and other customer support information on these systems. Essentially a customer calls in to the system for the first time and has faxed to them an index of available documents. They can then call up and order documents at any time by document number. Customers are happy because the information is available 24 hours per day and the companies are happy due to the decreased cost of labor for literature fulfillment and cost of printing literature.

Figure 3

Fax-on-Demand has many cost saving benefits. Figure 3 shows the typical savings of delivering 5 pages of information via FOD versus sending those same pages via U.S. Mail. Costs eliminated are labor, envelopes, printing costs, and postage.

The services provided by fax on demand are increasingly being incorporated into corporate web sites. Fax-on-Demand will always have its place as not everyone is connected to the Internet. There are far more fax machines in existence today than their are computers connected to Internet and people find faxing a simple way to receive information. In Europe, doing business by fax is far more accepted than in the U.S., there are also far fewer Internet connections in Europe compared to the U.S. For these reasons, the web will not eliminate fax usage in the near future.

In a world where a dog year and a web year are about equal ,2 months long, it is hard to make a statement about the Internet that will stand for much longer than the time it takes to print this document. Everyone seems to be talking about fax on the Internet, also called remote printing. Fax manufacturers are scrambling to show fax over the Internet at future trade shows, but no one seems to be able to define it.

The concept of Internet fax is different depending on what device you choose to use as a sender. If a fax machine is how you choose to send, then a fax machine with TCP/IP connectivity is required. This may simply be a fax machine with a NIC installed that allows it to communicated through the corporate LAN to the Internet. The other method would be for the fax machine to connect to the Internet on a dial-up basis by connecting to an Internet Service Provider (ISP) and then deliver the information. This once again is the approach being taken from the fax manufacturers.

The software companies of the world would of course like the PC to be the device that sends information. This piece of the puzzle is currently being done by at least one forward thinking company called FaxSav. They provide software free of charge to the customer who then can send e-mail or a regular print job from their PC over the Internet for delivery to a fax machine at the remote location. The drawback to this method is that the document must be created at the PC.

The way this system works, regardless of how you connect to it, is by using the TPC.INT subdomain. This has been around since 1993 but is just now becoming a much talked about technology. Essentially this subdomain is part of an e-mail address. While software and fax machines will hide these complicated e-mail addresses from the user, it is important to note that it is still e-mail. The e-mail will be routed to a "cell" that will have both a connection to the Internet as well as a fax connection to the Public Switched Telephone Network (PSTN). From the cell the information will be converted to a fax image and sent over regular phone lines. It is a blend of an e-mail server and a fax server working together to deliver information.

Who will pay for this service and how will the users be charged? Money is what pushes technology to the next step, but few are sure how to charge for these services. At the kick-off of the TPC.INT subdomain on July 16, 1993, only five small areas of the world were covered. The "cells" performing these operations were installed as a part of an "Internet community project" and charging for use was the last thing on their minds. As the technology proved feasible, many companies considered how to charge for these services.

Currently, FaxSav, formerly known as Digitran, developed a network of cells to deliver information throughout the United States and expand to the rest of the world. A cell is located within major cities within the U.S. and other countries. Information is sent by the user over the Internet using FaxSav’s software where it is routed to the closest cell to the destination. Then the Internet message is converted by the cell and faxed over the PSTN. If the message originates in the U.S. and is delivered to an oversees location, the potential savings in telephone charges is quite large. A cell, however, must reside in the destination country to make this a cost saving operation. The company providing the service, FaxSav in this example, will send a bill based on usage or a monthly flat rate depending on their billing methods. The savings are derived by the Internet performing the long haul delivery at a relatively minimal cost compared to a standard telephone call to transmit a fax.

As this technology evolves, a large market should open as additional cells and providers come on line. A few downsides to this technology are security and latency problems. Security is an issue as the mail message may be monitored along its’ path to the cell. Latency also presents a problem as e-mail can get delayed at a server or the cell delivering the fax may become overloaded and the fax may have to wait for the next available line before it can be sent.

There are many choices available to design an effective facsimile system. All of the devices described in this paper have their place in business today. It is important to utilize the knowledge learned in the fax communication section of this document and apply it to future purchases of facsimile equipment. Modem speed isn’t everything, company's should utilize faxes with leading edge compression methods to reduce their monthly phone bill. Fax servers and fax-on-demand can reduce the time required to get information in the hands of customers. Fax Broadcasting should be considered as an alternative to mailings and G4 fax to speed communication within companies with overseas offices or very high volume needs. Internet fax is on the horizon but must develop further both in hardware and software to be a true business solution. The choices are here today, and the correct selections will take a company well into the 21^st century.

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 Brobst, P., et. Al., Enhanced Fax Technology Seminar, Instant InfoSystems, Feb. 28, 1995, Los Angeles Airport Sheraton.

 Camarro, Kenneth, Fax Modems Demystified, Telecommunications, July 1993.

 Davidson, Peter, Faxing for Fewer Dollars, Office Systems 96, September 1996.

FaxSav, http://www.faxsav.com

 Hewes, Arlington, An Experiment in Remote Printing (FAQ", http://bond.edu.au/mirrors/fax/faq.html.

 Ibex Technologies, http://www.ibex.com

Malamud, C, & M. Rose, Principles of Operation for the TPC.INT Subdomain: General Principles and Policy, RFC 1530, Internet Multicasting Service, Dover Beach Consulting, Inc, October 1993.

 Pacific Bell, ISDN- A User’s Guide to Services, Applications & Resources in California", Pacific Bell, 1994.

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Ricoh Corporation, http://www.ricoh.com

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