Japan Communications to bring landline numbers to Japanese mobile phones

Frank Sanda, general telecom disrupter and founder and CEO of Japan Communications Inc., the provider of b-mobile products, recently announced on twitter that they are "about bring Tokyo landline numbers to mobile phones". That is, you could have a 03-xxxx-xxxx phone number attached to your smartphone. This will make your mobile number indistinguishable at a glance from a normal landline phone and will allow people to call you for a fraction of the cost they would incur if they called your mobile number.

He also said that the goal for JCI this next year is to move in the same revenue class (trillion yen) as NTT East and NTT West, and he thinks this "03 Smartphone" will do just that. And he also thinks the NTTs are going to need some help from someone, somewhere.

As far as I can see, the way this is going to happen is using VoIP ("IP softphone") with a "Class A" LTE connection. If so, not only will calling in be cheaper, so will calling out. Docomo charges ¥42 per minute to place an out-of-network call from an LTE phone. Doing the same with VoIP costs one tenth of that price, and if the connection is good, (I'll come back to that later) the voice quality is loads better due to the use of higher-quality codecs.

A bit of background:

Phone Numbers in Japan

In Japan, prefixes are typically reserved for particular types of devices. Mobile phones are allocated numbers beginning with 090, 080, and (recently), 070. Because incoming calls are charged to the caller, calling a mobile phone can be quite expensive. A commonly available option is an iP (VoIP) softphone app for your smartphone that is attached to a 050 number. However, the incoming calls to a 050 number can still incur a premium charge, above the cost of a standard local call. So, the best would be to have a normal number attached to your cellphone, for example a “03” Tokyo prefix.

Using a SIP client with a purchased 03 DID allows this right now, which is similar to what many of us do to get a phone number from “back home”. (I used to use callwithus, but now have a free DID from callcentric at which I point my Google Voice number.) While this is easy and straightforward in most countries, it is a bit more complicated here in Japan (though not impossible).

Quality of Service

Part of the reason why you can’t just get a prepackaged VoIP plan for your mobile phone with a 03 number is because there are minimum requirements before particular prefixes may be allocated. For a standard landline (固定電話) number to be allocated to a VoIP provider, the line must be CLASS A, capable of an R-factor greater than 80 for 95% of the time with less than 100 ms latency (according to wikipedia). A Class B (>70 and <150 ms) line may only be allocated to a 050 number.

A Caveat

LTE is technically Class A and could qualify for a standard landline number allocation.

Technically.

Realistically, I’m a bit skeptical how well this will work out. At peak times, the carriers are beyond capacity. I think the 95% of the time R factor requirement might be hard to meet. NTT East and West, as well as NTT Docomo and NTT Communications - hell, all the NTTs - are going to fight this. I’m sure all but Docomo will use the same argument that LTE doesn’t yet qualify as Class A. On top of this, you have inconsistent behavior with VoIP apps across different smartphones, as well as potential concerns with battery.

070 prefix phone numbers for 3G+ phones

Starting November 1st, 2013, Japanese phone numbers beginning with "070" will be available for use with 3G, LTE, and 4G cellular phones.

070 is not a new prefix for Japanese cellular phones. It's actually an old prefix: it was (and still is) used for Japan's last remaining 2G cellular network, called "PHS" in Japanese.

However, with PHS usage in decline and 3G/LTE/4G phone numbers in the 080 and 090 space being rapidly depleted, they have opened up parts of the 070 prefix for non-2G/non-PHS use:

• If the first digit after the 070 is a five or six (ex. 070-5XXX-XXXX or 070-6YYY-YYYY), it is still a Japanese PHS number
• All other number combinations could be either a PHS number or a 3G (or more advanced protocol) number

One interesting interoperability issue: because PHS 2G is not compatible with worldwide 2G GSM, they cannot send or receive SMS text messages.

That's how Japan's mobile email system got started: it was invented as an alternative to SMS.

From a consumer's standpoint, Japan's mobile mail alternative to SMS was superior: it allowed very long messages, it could interoperate and send/receive from internet email addresses, and allowed for rich content much like HTML mail.

From a carrier's commercial viewpoint, mobile email was a blessing because carrier provided email addresses, unlike phone numbers, could not to transferred to rival's networks (via MNP procedures), locking in customer loyalty; subscribers are hesitant to defect to other carriers because they would have to change/lose their Japanese carrier mobile mail email address.

It is only a recent phenomenon were people in Japan have begun to use SMS, although usage lags compared to carrier email. This is because of a few factors:

• It is only recently that the government MIC mandated that carrier's SMS interoperate (send/receive SMS text messages between Japanese and international carriers)
• Japanese 3G phones often had the SMS/MMS functionality buried in a deep submenu and referred to by strange brand names ("C-Mail" for KDDI/au SMS and "S!Mail" for Softbank MMS). Foreign phone operating systems, such as Android and iPhone, tend to feature the SMS/MMS features more prominently in their user interfaces. As Android and iPhone became popular in Japan, awareness of this functionality increased.
• When the restrictions were lifted for SMS/MMS interoperability, internet services (both in Japan and overseas) started increasing the use of SMS as a verification method for Japanese customers.

Thus, sending SMS/MMS messages used to never work if sent to a 070 number. Now, people will need to know if the the 070 phone is PHS or not if they want to send an SMS.

PHS' popularity amongst the general public in Japan has dropped precipitously now that 3G is ubiquitous and even faster phones (LTE/4G) are available everywhere. However, there is one area where PHS is still used: corporations still use them for internal "employee assigned" phones as they're very cheap to buy and use in bulk with a corporate contract. They tend to be used as pagers, either connected to humans or machines.

When 3G was introduced, they first exclusively assigned the 080 prefix to the devices. They then eventually added the 090 prefix. During this time when 3G was new, some people were surprised to hear people tell them that their mobile number was "080", thinking that only "070" numbers were mobile numbers. Now, with the younger generation, some people may express surprise that somebody has a "070" number, as younger people associate the 070 prefix with old technology.