
Japan plans to create 10B 14-digit phone numbers with 5G era approaching - Ultramanoid
https://www.japantimes.co.jp/news/2019/05/14/national/japan-plans-create-10-billion-14-digit-phone-numbers-5g-era-approaching/
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lifthrasiir
As many seem to wonder about details, this is my understanding of the
situation (I've posted some below, but this format would be better):

\- 070, 080 and 090 prefixes are being used for mobile phones and M2M
(machine-to-machine) communications since 1999. They are 11 digits long and
the future shortage was expected.

\- 020 prefix was created exclusively for M2M in 2017. The existing M2M
numbers do not have to migrate, but it is recommended for most cases as 020
prefix has no requirement for the number portability and QoS. So the creation
and expansion of 020 prefix is irrelevant to the population estimate.

\- Since 0204 prefix was already used for pagers, and since 0 is a trunk
prefix in Japan, there were initially 80 million numbers available, starting
with 0201--0203 and 0205--0209.

\- It was envisioned that 80 million numbers do not suffice for the future
expansion of IoT devices, so there was already a plan for 13- or even 14-digit
numbers at the time. Note that while 14-digit numbers are within the E.164
recommendation (e.g. +81-20-XXX-XXXXXXXX = 020-XXX-XXXXXXXX) it does seem to
cause some serious engineering problems to tackle.

\- 020 prefix was allocated in the increasing order, so numbers up to
020-536-XXXXX are allocated as of May 2019 [1]. It is expected that the digit
expansion will happen in the remaining area.

\- While 020 will greatly postpone the exhaustion, existing 070--090 prefixes
would be eventually full in the future. 030, 040 and 060 prefixes once used
but now vacant are reserved for this inevitability.

[1]
[http://www.soumu.go.jp/main_content/000477284.pdf](http://www.soumu.go.jp/main_content/000477284.pdf)

~~~
JimboOmega
But why would Japan run out of phone numbers with the population shrinking?

While of course IoT devices need to be addressable, that's more of an IPv6
problem than a phone number problem.... right? A person might have a few
numbers, at most - and a flat if not shrinking number (I used to have home,
work, cell; but have only had cell for a while now)

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sschueller
What do we have IPv6 for? I thought these 4G/5G networks run a TCP stack and
telephony on top of it. Why do we phone numbers for device to device
communication?

~~~
lemcoe9
Give me a call at [2607:f8b0:4004:802::200e] and I'll tell you.

~~~
lmm
A phone number is just an entry in my phone's address book - I don't think I
dial them by hand any more often than I type an IP address by hand.

~~~
vidarh
Exactly. I don't know my moms phone number. Or my sons. Or any friends or
colleagues. The only phone number I remember is my childhood home phone number
that was drilled into me 35 years ago, and my own number.

~~~
snuxoll
There are exactly 6 phone numbers I can recall from memory, one of them is my
grandfathers which I’ve known since I was little, the others are family
members on my phone plan because we got assigned a block of contiguous numbers
when we switched to T-Mobile.

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srmarm
Considering > about 32.6 million of the 80 million numbers starting with 020
had already been assigned

It seems a bit odd that they're putting the 14 digit numbers on the same 020
prefix that half the 11 digit numbers have already been released for. Seems
like some chance for confusion where the first 11 digits collide. I'd have
thought it'd make more sense to give a new 3 digit prefix for this class of
numbers.

~~~
toast0
Someone mentioned they've been assigning prefixes in 020 to carriers in order.
The thing to do then is make say 020 [0-3] be 11 digit numbers, and 020 [4-9]
be 14 digit numbers. Then it's easy to validate.

I doubt they would assign 14 digit numbers where the 11 digit prefix was
assigned to someone else, but, if they were desperate for space, they might
make the 020 prefix all be maybe 11, maybe 14 and as 11 digit numbers were
released, issue 14 digit numbers with the same prefix.

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avar
How are these allocated under the hood? Wouldn't it make sense to stick all of
these phone numbers in an IPv6 /64 at this point, with the "14 digit" just
being a convention mapping to some range in that space?

~~~
sametmax
Is a simcard always supposed to have the same ip ? How would ip spoofing would
affect the phone network ?

~~~
zamadatix
Why not, a single /64 has way more address space than a MAC-48 and we've been
permanently assigning those to hardware (including phones) for years.

I don't think the spoofing question would change based on what identifier you
use. Whatever identifier you give you have to ask and answer the question.

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andyjohnson0
Regarding machine-to-machine communications, I'm wondering if these extra
numbers are needed because mobile devices require a phone number to interface
to mobile networks, even thought they typically only initiate _data_
exchanges. Or‡ are there devices that actually receive phone calls - as in
dial-up?

‡ not familiar with tech in Japanese infrastructure

~~~
michaelt
There are certainly cheap GPS trackers that send SMS messages. Of course,
those are usually sold to consumers rather than into the M2M market.

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gumby
M2M should just use IPv6 natively which would leave enough 11 digit numbers
for human use.

And the fact that they are willing to go to 14 digit means they know that few
people dial numbers manually anyway.

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throw0101a
In case anyone is wondering, ITU E.164 specifies that maximum length of a
phone number is 15 digits:

* [https://en.wikipedia.org/wiki/E.164](https://en.wikipedia.org/wiki/E.164)

* [https://en.wikipedia.org/wiki/Telephone_number](https://en.wikipedia.org/wiki/Telephone_number)

Given that Japan's country code is +81, that leaves thirteen digits for
however Japan wants to assign it internally.

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GreaterFool
Given that the population of Japan is <130M and is only going to go down from
now on, what's the point? :)

14-digits?!?! Yikes. Not looking forward to using that!

~~~
SenHeng
For those that haven't RTFA Japanese phone numbers have 11 digits,
123-1234-1234, of which the first three are reserved as identifiers. A lot of
people also carry two phones. Many companies also still have fax machines.
Even my pocket wifi has its own phone number (can't be dialed).

8 digits is only 100,000,000 possible unique numbers. So it looks like they're
simply running out of numbers.

~~~
delhanty
>Japanese phone numbers have 11 digits

10 digit numbers are still in use:

[https://en.wikipedia.org/wiki/Telephone_numbers_in_Japan#10_...](https://en.wikipedia.org/wiki/Telephone_numbers_in_Japan#10_digit_numbers)

~~~
SenHeng
I've always thought of those as having an invisible 0 that's filled by the
system, like when you call a landline number.

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thefounder
At some point we should stop using numbers and use something like an email
address.

~~~
epanchin
How would international calls work?

~~~
Moeg
The same way website addresses work, DNS type of thing?

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lcnmrn
What's wrong with case insensitive letters?

US-ABC-900-900 can be a beautiful phone number and global. 165,216,101,262,848
numbers per country.

US-ABCD-900E-900R in case we run out of numbers again.

~~~
jasonhansel
Most countries don't use the English alphabet, so I'm not sure if that would
work outside the US.

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dagw
_Most countries don 't use the English alphabet_

I strongly suspect that most countries (and certainly a majority of the world
population) use a super-set of the English alphabet though.

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sundaeofshock
Your suspicions are incorrect. Only 36% of the world’s population uses the
Latin alphabet.

[https://www.worldstandards.eu/alphabets/](https://www.worldstandards.eu/alphabets/)

~~~
__HYde
If you count Chinese who are using Pinyin that jumps to being a majority using
latin.

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lostmsu
Can't we use email addresses instead?

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noselasd
Why ?

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lostmsu
Why not? Federation, one less identifier to remember, can send an email, if
the callee unavailable.

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manjana
14-digit!? No one can possibly remember that easily... Why not alphanumeric
and make the address space so big that people can chose one that would be
possible for a stranger to remember immediately - like we have domain names,
e.g.: cecelia_alberto OR charlotte1231

~~~
Ultramanoid
Does anybody actually remember phone numbers these days ?

Edit : I do remember the half a dozen I use or might really need, and already
feel like an outlier. ( And as pointed in another comment, they're already 11
digits each. Not that much of a difference. )

~~~
manjana
No, properly not perhaps. But it would be a nice feature when you have to
exchange phone numbers.

~~~
Ultramanoid
We exchange cards as a matter of daily interaction. The biggest issue is
reading properly a name ( kanji ), not the other data in them.

