Re: Telephone Area Codes and Prefixes

So how would they pr> The other cool thing about that number is that it is of
> course the lowest (generally-dialable) phone number in > the entire world!

R> In the telephony world 0 is a ten not a null, so

wouldn't that be a pretty high number?

PAT wrote:

I th> True for North American phone systems. > There are other, incompatible, phone systems that use different > encodings. One uses two through eleven pulses for the digits, with > 'n+1' pulses for 1-9, and eleven pulses for '0'. This greatly > reduced false-digit detection from the equivalent of a 'switch-hook > flash'.

You may be thinking of Sweden.

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But note that on the Swedish dial, zero is encoded as one pulse, not eleven. Of course, that would still prevent wrong numbers due to false-digit detection: the caller would get the operator.

Assuming, of course, that "false-digit detection" is actually a problem. I always thought it was, but our friend Wes Leatherock thinks otherwise. Wes?

PAT continued:

Exactly how it [digit zero] is translated if being 'tone dialed' is > not known to me. Is it still considered a 'ten'. In that case, are > the '*' and '#' keys considered eleven and twelve when dialed? PAT]

Tone dialing is accomplished by transmission of two audio tones within the 300-3000 Hz voice bandwidth; hence the terminology "dual-tone multi-frequency" (DTMF) signaling. Each digit (including *, #, A, B, C, and D) is encoded by a different combination of a set of eight audio tones. Digit zero is encoded as 941 Hz + 1336 Hz.

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No matter how we encode numeric digits, we have to assign *something* to represent zero. We can't represent zero by nothing at all (although I've been told that Roman numerals don't have a zero). Over the centuries, we humans have evolved numerous conventions: 0, 000,

0000, 0x00, "zero", "oh", "null", "nought", "goose egg", "zilch",...

In the telephony world, zero can be encoded as one pulse, ten pulses, eleven pulses, 941+1336 Hz, or whatever. But for the purposes of assigning human-readable telephone numbers, a zero is a zero is a zero.

Therefore, I agree with Goudreau: 201-200-0000 is the lowest (numerically) in the NANP.

And I suppose that:

- If you're counting dial pulses, the lowest would be 212-221-1111 (except that it might be tied with 212-212-1111 if the Illinois Commerce Commission were assigning NNXs in New York).

- The highest (numerically) would be 989-999-9999, in an unassigned NPA-NNX in Michigan.

- The highest (counting dial pulses) would be 909-900-0000, an unassigned number in the Fantana, California rate center.

Neal McLain