Talk:Overlay complex

This article is written in American English, which has its own spelling conventions (color, defense, traveled) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.

Telecommunications

	Telecommunication portal This article is within the scope of WikiProject Telecommunications, a collaborative effort to improve the coverage of Telecommunications on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.TelecommunicationsWikipedia:WikiProject TelecommunicationsTemplate:WikiProject TelecommunicationsTelecommunications articles
???	This article has not yet received a rating on the project's importance scale.

First overlay plan?

Pursuant to my edit comments, does anyone know offhand what the first proposed and/or implemented overlay plan was? - Keith D. Tyler ¶ 18:46, September 1, 2005 (UTC)

As far as the U.S. is concerned, the first overlay as such was in New York City in 1992 when the new 917 code overlaid the existing areas of both 212 & 718. However, in this case the new 917 code was used initially only for new cellular and pager numbers. It was later opened up for regular POTS use as well.

Maryland introduced two full overlays (i.e. open for all uses from the beginning) at the same time in 1997, with 240 overlaying 301 and 443 overlaying 410. 80.229.125.177 (talk) 18:05, 1 July 2013 (UTC)[reply]

The 301 overlay was the first to break seven-digit local calls to the same area code. There has to be some sort of booby prize award for that. K7L (talk) 04:58, 2 November 2014 (UTC)[reply]

Merge with Area code overlay completed

The pages were different with the former mostly being a list. So I moved that page to List of area code overlays and then changed the newly formed redirect to here.

outside North American Numbering Plan

any examples? For now I put it in Category:North American Numbering Plan NoGringo 19:19, 18 August 2007 (UTC)[reply]

I'm not aware of any in the UK, although some people seem to think "0203" is an overlay for London - see Erroneous UK telephone codes for how this mess came about! Timrollpickering 02:27, 16 November 2007 (UTC)[reply]

Actually come to thing of it the sub-area codes in London have had overlays - see 020#History. Timrollpickering 02:33, 16 November 2007 (UTC)[reply]

The exchange codes within a director area are really a different case though, unrelated to STD/area codes. The use of more than one exchange prefix to cover a particular area of a large city has been common for many years, since with 7-digit numbering schemes it's not that hard for certain densely populated areas to exceed 10,000 numbers. London and New York are two such examples.

As far as the U.K. is concerned, the stage is now set for the introduction of the first overlay area code as such at some point within the next few years. Bournemouth moved to a closed dialing plan in November 2012, meaning that the 01202 code now has to be dialed for all calls to 01202 numbers, even when calling from within the area. Initially, that will allow the allocated of 01202 0xxxxx and 01202 1xxxxx as regular subscriber numbers to provide temporary relief (they were already in use for certain special purposes). Once those ranges are exhausted, a new area code will be assigned as a Bournemouth overlay. 80.229.125.177 (talk) 18:14, 1 July 2013 (UTC)[reply]

North America is a special case because of the inflexible way a fixed-length number (1-NPA-NXX-XXXX) has been hard-coded into the design of the entire system since the advent of direct distance dial in 1951. That sort of thing doesn't happen in the UK or most European countries; local numbers can be lengthened from seven digits to eight (as they were in London) without the entire system imploding. NANP is going to be messy once the last area code is squandered and the whole system has to change. K7L (talk) 04:56, 2 November 2014 (UTC)[reply]

The plan is for each 3-digit area code to be turned into a 4-digit area code. During the transition, the new digit will be the second digit, and will be a 9. Once the transition is over, the other numbers will be available, multiplying the number of possible area codes by about 10 (minus, of course, the few special numbers that will remain reserved). Currently, the number 9 cannot be used as the second digit in an area code, and the reason for this is specifically to allow for an easier transition when the inevitable day comes that area codes in North America are exhausted. _{ping me if you reply here.} Etamni | ✉ | ✓ 01:21, 3 November 2015 (UTC)[reply]

Denver/Confusion

Hi everyone! This is kind of odd... certainly not my first talk post, but my first one when logged in. Now I know what I'm doing! Yay! O.K. more to the point, I believe an overlay was done in Denver Colorado, but I'm not sure. (I live in a different area code and nobody I know there has the different one)

Also, why is everyone so whiny about these things? They're a neccesary byproduct of growth, but people say plans have been "thwarted" like the area code people are trying to take over the world! Of course this is going to happen, there are only 10^7 possible numbers in an area code, from 000-0000 to 999-9999 -- 10,000,000 numbers. If we used all of them, it wouldn't happen much, but I think some aren't used. Have you ever SEEN a 000-0000 number> That's a weird one!

well, that's what I think. See Ya'll around! —Preceding unsigned comment added by Waladil (talk • contribs) 17:34, 11 June 2008 (UTC)[reply]

Denver has had 720 as on overlay on 303 since September 1998.

As for 10 million numbers being available within each area code, it's actually fewer than that. Because of other characteristics of the North American numbering plan, you can't have numbers beginning with 0 or 1, so that brings it down to 8 million. Then there are the reserved n11 service codes (411, 911 etc.), plus other 3-digit codes which are reserved for telephone company use, etc. Of course, that still leaves a good few million numbers per area code, but the exchange prefix (the first three digits) is still allocated in a way which determines where within the area code the call will be directed. At one time, that's as far as the breakdown went, so even in a small town which was likely to need no more than, say, 2000 numbers for the foreseeable future, it still needed a full block of 10,000 numbers assigned. In more recent times, there has been a breakdown of assignments in blocks of 1,000 rather than 10,000 in some areas, but this is still a limiting factor to an extent.

The split vs. overlay argument is likely to continue, but slowly the NANP is going in the direction of adopting overlays rather splits, and no doubt there will come a time when most if not all areas have overlays and all calls will be dialed as 10/11 digits. 80.229.125.177 (talk) 17:55, 1 July 2013 (UTC)[reply]

The problem isn't that 10000 numbers are being given to each small town. The problem is that 10000 numbers were being given to each carrier in each small town. There are towns of less than 5000 population which have 80000 numbers spread across two overlaid area codes, utterly pointlessly. That wastes numbers. These are not "a necessary byproduct of growth", there's no need for a separate rate centre for every tiny speck on the map (some of which have no physical telco central office) with a block of 1000 or 10000 numbers to each of a long list of competing carriers in each. K7L (talk) 04:53, 2 November 2014 (UTC)[reply]

I just love clarifications.

Overlays have also become more popular than split plans in Canada during the previous decade.

Previous to what? —Tamfang (talk) 04:25, 7 August 2010 (UTC)[reply]

The Canadian overlay infestation began in 2001 with 416/647. K7L (talk) 04:46, 2 November 2014 (UTC)[reply]

Canada

"By 2013, as mentioned above, seven-digit dialling had been eliminated in all eight of Canada's original numbering plan areas."

Factually wrong. There are nine original NPA's (from the 1947 allocations): +1 604 403 306 204 613/416 514/418 and 902. Where do you get eight? 66.102.87.40 (talk) 19:29, 8 November 2022 (UTC)[reply]