Slashdot Mirror

The cost of building and maintaining ever faster telecoms networls (celullar and otherwise), paired with smaller cell sizes, and NIMB syndrome were communities reject cell towers (but demand service nonetheless) for aesthetic or "health" reasons (in the case of celullar), lead to this.

Fisrt came the sharing of the long range towers (think microwave repetition and concentration points), then came the sharing of rural cell towers, then urban cell towers.

The next step is RAN Sharing. And is being baked in 5G standards (and backported to 4G).

[Carefull, PDF]
https://www.gsma.com/publicpol...

For more info on the topic, and in particular, specific provider cases, google is your friend.

I just checked using over my Verizon mobile phone and sure enough there is the X-UIDH header.

I just checked with my AT&T mobile phone and found an "x-acr" header which seems to serve much the same purpose, so switching away from Verizon might not help. (The header is not present when accessing the site through a VPN, so it wasn't sent by the browser.)

The content seems to be based on the Anonymous Customer Reference concept promoted by the GSM Alliance.

AT&T already has an IMEI blacklist. I believe they are exchanging data internationally already too. (The GSMA has an international shared blacklist - http://www.gsma.com/technicalp... )

See above. But here's the link again: GSM Association Official Document 12FAST.13 - Embedded SIM Remote Provisioning Architecture.

To fix this issue, the GSMA has developed a non-removable SIM that can be embedded in a device for the duration of its life, and remotely assigned to a network. This information can be subsequently modified over-the-air, as many times as necessary.

What this seems to do is take control away from the user, who could swap SIM cards, and give it to some carrier. This looks like something where you beg and plead with your old carrier to let you switch your device to a new carrier. There's a lot of elaborate key management in this system, and compromise of certain keys could break the whole system.

Spec for the system architecture.

The idea that Google is going to make money on subscription services is dubious.

By wireless I assume they mean Cellular.

Marketing Cellular to "sub-Saharan Africa" might work because The number of mobile phone users in sub-Saharan Africa rose by 44 per cent to 475 million, compared to just 12.3 million fixed line connections, representing the highest proportion of mobile versus fixed line connections in the world.

By comparison, there are only 326 million subscribers in the US.

(There is little street level wired infrastructure there, and cellular is the big player. (pdf). )

So cellular penetration is already bigger there than you might imagine, and apparently there is no problem affording handsets, and computers. So if there is enough money to buy equipment there is probably enough money to support advertising.

I would worry more about becoming targets for muslim extremists than failing to gain traction due to poor market conditions.

The ability to deny service to a blacklisted device already is part of the GSM standard and the central registry needed to get this working:

http://www.gsma.com/technicalprojects/fraud-security/imei-database

Now it is only a matter of getting the carriers to actually use this list to deny service. In most SGSN, all it takes is changing a config flag.

Yes, that hard!

I didn't mean to imply they wouldn't unlock your device for international travel but if you look at the iPhone 5 for AT&T (Model A1428) you see it is only compatible with Bell, Rogers, and Telus but the world phone version (Model A1429) covers all non-North American LTE carriers. Apple didn't need to produce a separate phone for N.A. but they did. So if you take your iPhone abroad your LTE won't work. Now imagine we've moved to VoLTE...how do you make a call? I'm sure we'll have legacy voice for a long time to come but I can't help thinking about these things.

According to the GSMA, the IMEI number is globally unique amongst GSM IMEI and CDMA MEID numbers.
http://www.gsma.com/newsroom/ts-06-6-0-imei-allocation-and-approval-guidelines/

You're right. Here is a document dating back from July 2011 (the emphasis in bold is mine).

GSMA has launched an initiative to fight mobile theft, and has worked on IMEI security best
practice. GSMA and DIGITAL EUROPE members drafted and approved 2 common
documents:

Technical Principles: intended to strengthen the security of the International Mobile
Equipment Identity (IMEI)
* GSMA Doc Reference: Security Principles Related to Handset Theft 3.0.0
* DIGITAL EUROPE CCIG Doc Reference: DIGITAL EUROPE Doc: 04cc100

Process in place: GSMA and DIGITAL EUROPE have agreed on a process to report alleged
breaches of IMEI integrity and on the introduction of counter-measures to correct and
improve IMEI security.
* GSMA Doc Reference: IMEI Weakness and Correction Process 3.0.0
* DIGITAL EUROPE CCIG Doc Reference: DIGITAL EUROPE Doc: 04cc101

Apparently to the drafters of that document, IMEI integrity and security (whatever that means to them) is something that must be constantly monitored and maintained. And while this does not prove my original point.

As a mobile software developer, until I know what those "counter-measures" are supposed to be in the first place, I'm just going to assume that what was true 10 years ago can still be true today, and I can not completely rely on an IMEI being completely unique. So whatever software I build that takes this assumption to heart, I'll have to leave a process in place to manually override my system if that that particular edge case ever comes up.