4. Long Term Numbering Plan
5. MULTIFUNCTIONAL ADDRESSING SYSTEM
Consider now the proprietary Multifunctional Telecommunication Addressing System (MTAS) developed by Telecom Addressing Group and disclosed herein (Garfinkle, 1997). Although the MTAS changes the number of characters required to access various telecommunication devices, the additional characters do not enter directly into any subscriber's primary telephone address, and thereby do not affect the perceived bound groupings of three and four characters. The ultimate usefulness of the MTAS however requires that it is utilized in a particular manner rather than indiscriminately.
 
MTAS Protocol
The keys designated <*> and <#> with the multifrequency tones 941/1209 hertz and 941/1663 hertz respectively are not used at present in telephone addressing except for special customer services provided by LECs. Although these tones are used by automated devices controlled by multifrequency tones, and to simply add these keys to new telephone addresses would lead to the same confusion as would adding additional characters, and would add significant mnemonic difficulties, leading to increased misdialing. According to the MTAS protocol these two multifrequencies 941/1209 hertz and 941/1663 hertz serve rather as markers or place-setters designating the type of telecommunication equipment to be accessed.
 
To remember a string of random number can be quite arduous, and recall them without random errors at any occasion at which it might be necessary can be even more formidable.

 
To alleviate this problem telephone addresses are presently displayed in the PSTN fixed group arrangement.

Although we do not consciously remember the group divider it remains as part of the array stored in our memory, and when we recall a telephone address we recall as well the divider, and momentarily pause at the divider when reciting or recording the address. Essentially we do not recall the address as a single bound group but as an array of two bound groups.
 
According to the MTAS protocol a marker doublet is placed in the array for multifunctional purposes. This marker will be any combination of <*> and <#> tones grouped in pairs. For example, if <**> appears in the address then the caller will be accessing a facsimile machine. However the position of this marker in the array will be as important as the marker itself.
 
Consider the case of the marker preceding the address as shown below. Although the numerical characters are the same, the first example indicates a telephone line and the second example a facsimile line, both for the same subscriber.

However the expected seven-character array separated into two bound groups has now been broken. The first position is now occupied by an access code, either blank <__> or <**>. Worse the mnemonic is lost, with the added liability that PSTN compatibility is lost.
 
Consider now the preferred embodiment of the MTAS arrangement shown below.

Not only is the expected address preserved as two bound groups with a divider, but the marker doublet <**> fits comfortably between the bound groups. The mnemonic is preserved. Most importantly, because the marker doublet is not a numerical character it cannot be confused with the address.
 
Practical Considerations
Consider the MTAS in practice. A business subscriber at present has two lines for example, a regular telephone line and a facsimile line. These lines have the addresses
 

Telephone: 321-1234 and Facsimile: 321-2345 .

 
According to the MTAS protocol the subscriber would have the choice of changing his facsimile address to a sub-address as an optional service, much like call forwarding or caller ID, so that
 

Telephone: 321-1234 and Facsimile: 321**1234 ,

 
each still independent, autonomous and distinct lines. In both cases the telephone address terminates with a four digit line number, signaling the end of the address sequence as expected by PSTN. There is now an extra character, but it is essentially imperceivable to the telephone user as it requires neither another address character to be recalled nor alters the conventional bound grouping of characters. The <**> tones serves solely as a marker and indicates to the PSTN that a facsimile machine is being accessed. As long as the <**> multifrequency can be recognized by the PSTN switch, it is a matter of programming the PSTN software to secure the correct interconnection.
 
As in conventional practice the subscriber's facsimile machine would be accessible by both the old and new addresses for some adjustment period after the conversion. Of course any preceding area code will have no effect on this arrangement. Although the access multifrequency tone <n> is recognized by the switching program to normally indicate that ten characters are to follow, a 941/1209 hertz multifrequency doublet <**> embedded within the dialed sequence following the first six characters after the access tone would superseded this command, indicating that four subsequent characters will follow.
 
Only the sub-address 321**1234 need appear on telephone directory listings and company letterheads inasmuch as the symbol <**> would indicate that a telephone is also accessible at the primary address, greatly simplifying commercial telecommunication access, an advantage readily perceived by marketers, promoters and advertisers.
 
Business and residential subscribers who do not wish general access to their facsimile machines would simply request that the symbol <**> be omitted from their telephone directory listing.
 
Most significantly however, the facsimile address released for reuse 321-2345 can itself accommodate the two lines of another subscriber:
 

Telephone: 321-2345 and Facsimile: 321**2345 .

 
The functionality of the MTAS can be further expanded moreover by

Most salesmen need cellular phones on the road, and it would be both convenient and smart from a sales viewpoint if its sub-address was the same as his primary telephone address, accordingly

 

Phone: 321-1234, Facsimile:  321**1234 & Cellular: 321##1234.

Consider again all of the various telecommunication devices commonly being accessed by telephone lines: telephones, facsimile machins, cellular phones, modems and pagers. These devices can now be assigned a specific marker that would be fixed for each such device.

If our salesman has a laptop computer, which increasingly has become a competitive necessity, his modem sub-address would be 321*#1234: very convenient and most expedient, as would a pager with 321#*1234.
 
Essentially, the salesman's five lines function independently because each has a separate and distinct line number, however their sub-addresses are simply expected variations on the primary address.

All sub-address lines operate autonomously and as required simultaneously.

Contents

6. SIGNALING AND CONTROL