Sign in to follow this  
Followers 0
MSIGuy

How many useable phone numbers?

18 posts in this topic

So I was having a conversation with a guy, and he said that the US must have a rather limited number of phone numbers available based on our 1+XXX-XXX-XXXX system as opposed to the UK's system.

Now a quick calculation of 10c10 gets us 10 billion numbers, but that's assuming that every area code is filled, that the 555's are used as well as the 000's and 999's, and lots of other blocks that arent' normally used are being calculated.

So my question is, what's the best estimation of how many numbers the US has available based on our 10 digit phone system?

0

Share this post


Link to post
Share on other sites

So my question is, what's the best estimation of how many numbers the US has available based on our 10 digit phone system?

Seeing as how there are 298,908,863(roughly) in the U.S., one would assume about that many numbers. Give or take the businesses, multiple phones, people that don't have phones, and all of the 867-5309's that can't be used anymore of course ^_^

0

Share this post


Link to post
Share on other sites

No, I mean like how many are possible.

I already know that there are 10 billion possibilites if we're counting all 000's and everything, I'm pretty much looking for how many exceptions there are, how many numbers can't be used, and subtract that from 10 billion.

0

Share this post


Link to post
Share on other sites

No, I mean like how many are possible.

Well here is a list of number prefixes.

Why do you want to find out?

For current area codes: here

Edited by Dare To Imagine
0

Share this post


Link to post
Share on other sites

Actually, replace the 10 X's with 10 nines and you get 9,999,999,999. One shy of your 10 billion.

Sorry, couldn't resist. ;)

I just did an area code lookup earlier tonight to check if it was valid. I suppose a quick and dirty script to query the site could yield a fair approximation based on area codes.

Or...

I just went to

http://www.bennetyee.org/ucsd-pages/area.html

and got a list of area codes for the US, Canada, Guam, Virgin Islands and Puerto Rico. We seem to share area codes with each of them. Using 'wc -l' it showed that there are currently 383 area codes in use out of a possible 999. I removed other countries and things like reserved and toll numbers which left 319 area codes in use for civilians and government.

I ran 'cut' on the file to get just the numbers and then 'wc -l' which tells me how many lines are in the file. That showed 319 used area codes with 616 left unassigned. That makes a total of 9,349,999,065 numbers available for normal phone use. I think. :blink:

Hm, with over 9 billion numbers available the argument may be moot. For a couple years anyway. How many kids are you going to have? :P

0

Share this post


Link to post
Share on other sites

That makes a total of 9,349,999,065 numbers available for normal phone use. I think. :blink:

Nah, that can't be right. Given the current census, 298,908,863 people, that would mean that there were 31 numbers a person.

0

Share this post


Link to post
Share on other sites

There are a whole host of things you guys arent considering.

Originally, area codes were assigned as NYN, where Y was a 1 or 0. That has now changed so it is now NXN. So excluded are 0XX, 1XX, and N11 combinations for area codes. There are lots of other reserved area codes, 855,866,877,888,900, 700 and 710 for starters.

Also, there is not universal 10 digit dialing, which brings up tons of issues... In a multi area code LATA with 7 digit dialing, exchanges cannot be the same as surronding area codes. Of course the exchanges would also need to follow the area code type numbering scheme, plus typically not 555, etc.

Since blocks of numbers are sold to companies, even if not used, they are not 'usable' for anyone else.

Also, 'churned' numbers are kept out of use for at least a few months.

And then there are all kinds of carrier indepdendent special numbers (which I suppose dont really qualify

anyway :))

and all of the 867-5309's that can't be used anymore of course happy.gif

They can surely be used. But they call them vanity numbers and charge you much more for that privledge ^_^

Moved to OSP

0

Share this post


Link to post
Share on other sites

There are a whole host of things you guys arent considering.

Also, 'churned' numbers are kept out of use for at least a few months.

What are "churned" numbers?

0

Share this post


Link to post
Share on other sites

http://en.wikipedia.org/wiki/Churn_rate

When people drop their telephone service, the company can't just go and give that number to someone else right away, or that person would receieve lots of calls from people trying to reach the original owner. The intermediary period is supposed to resolve this best as a comprimise of cost. (Remember, calls and complaints cost money!)

0

Share this post


Link to post
Share on other sites

I think the answer he is looking for is how many possible numbers are out there for regular people to acquire. Excluding gov prefixes and un-usable area codes ect...

0

Share this post


Link to post
Share on other sites

What are "churned" numbers?

though the term 'churned' doesn't quite fit what i think he's trying to say, I believe he is referring to numbers that people once had, but have since changed thier number. The old number is automatically re-assigned, it likely takes them a while to get around to collecting all the unassigned numbers hidden in the mess.

They can surely be used. But they call them vanity numbers and charge you much more for that privledge happy.gif

nothing quite like the feeling of spending extra cash to be pranked. (damn you PLA!!! :P )

0

Share this post


Link to post
Share on other sites

http://en.wikipedia.org/wiki/Churn_rate

When people drop their telephone service, the company can't just go and give that number to someone else right away, or that person would receieve lots of calls from people trying to reach the original owner. The intermediary period is supposed to resolve this best as a comprimise of cost. (Remember, calls and complaints cost money!)

Much thanks.

0

Share this post


Link to post
Share on other sites
Nah, that can't be right. Given the current census, 298,908,863 people, that would mean that there were 31 numbers a person.

WHAT!!! How come I only got 27 numbers then???? :D
0

Share this post


Link to post
Share on other sites
Nah, that can't be right. Given the current census, 298,908,863 people, that would mean that there were 31 numbers a person.

WHAT!!! How come I only got 27 numbers then???? :D

Check it again, cause I did..

9,349,999,065 divided by 298,908,863 equals exactly 31.280434347642612390519848854398 which I rounded down to 31.

Math is hard. :roll:

Edited by Dare To Imagine
0

Share this post


Link to post
Share on other sites

So my question is, what's the best estimation of how many numbers the US has available based on our 10 digit phone system?

If X denotes a digit that can take any of the values 0 through 9, and N denotes a digit that can take any of the values 2 through 9, then any phone number in North America must be on the form NXX-NXX-XXXX.

This gives 8 x 10 x 10 = 800 area and office codes, and 10⁴ = 10,000 station codes. So there are exactly 800 x 800 x 10,000 = 6,400,000,000 different numbers available in North America.

Edit: If you want a to know how many numbers that can actually be used, you must of course find out how many area codes there are in use (I believe there are currently about 350), and how many of the possible central office codes that will not be used: http://www.nanpa.com/reports/reports_cocodes_assign.html (like 205-211 and 217-500). So you can get for example (350 x 800 - 1000) x 10,000 ( ([area codes] x 800 - [unassignable central office codes]) x 10,000 ).

2,700,000,000 is probably a fair estimate, but the number grows as new area codes are introduced. Just one more area code gives almost 8,000,000 new possible numbers.

Edited by snow
0

Share this post


Link to post
Share on other sites

The UK system must not be great either - london in particular kept changing area code and number of digits, as they ran out of numbers. Each time they changed, of course, they hailed the new numbering plan as the plan to end all plans, no number shortages ever. One problem with our numbering plan is that some area codes have few numbers in use, and some area codes are full. They aren't distributed evenly.

My area code uses 6xxxx / 7xxxx and 8xxxxx and each exchange (central office) in the 8xxxxx prefix has 10000 numbers despite how big it may be. My exchange is roughly 1000 lines, and it has 10000 assigned (one of the reasons for the numbering shortage is that ofcom didn't/doesn't assign numbers in smaller blocks than 10000)

We have a real mix of numbers.

You can get

(0xxxx) xxxxx (used in some places, not too common)

(0xxxx) xxxxxx (the most common, used everywhere else apart from:)

(0xxx) xxx xxxx (used in major cities

(0xx) xxxx xxxx (the newest, used in london, southampton, portsmouth, coventry and others - THERE IS NO 4 DIGIT AREA CODE despite some people will have you believe, 020 7 not 0207)

01 = landlines

02 = landlines, 0xx xxxx xxxx format

03 = unused

04 = unused

05 = freephone, 055/056 is voip iirc

06 = was used, now isn't

07 = 070 is personal numbering (35-50p/min), 076 is pagers, 077/078/079 is mobiles

08 = freephone, 0844/0845/0870/0871 rip-off numbers

09 = premium

1xxx / 1xxxx = carrier access codes

100 = operator

155 = international operator

101 = non-emergency number (10p/call)

131/132 = cable and wireless

118 xxx = directory enquiries

999 and 112 = emergency

150, 151 = faults

these are applicable to BT lines, cable operators may not have all these.

I don't know how many usable phone numbers, but if there are 67,908,546 mobile subscriptions (wikipedia) in the UK and 3 area code prefixes are enough to number them all then we have a hell of a lot.

Edited by mo0
0

Share this post


Link to post
Share on other sites
Nah, that can't be right. Given the current census, 298,908,863 people, that would mean that there were 31 numbers a person.

WHAT!!! How come I only got 27 numbers then???? :D

Check it again, cause I did..

9,349,999,065 divided by 298,908,863 equals exactly 31.280434347642612390519848854398 which I rounded down to 31.

Math is hard. :roll:

I think he meant, "Why am I only in possession of 27 numbers then?"

Incidentally, for the Tommy Tutone bashers:

A scan of every 8675309 by area code.

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0