back to article T-Mobile goes Apple/Google route by separating phone numbers and devices

T-Mobile is taking a leaf out of the tech industry book and separating phones from their numbers. The company's Digits service will allow you to pick up calls from any device – in much the same way Google does with its voice service and Apple does with its AppleID. It will launch on May 31. The service has been in beta for …

  1. Anonymous Coward
    Anonymous Coward


    Not even Google Voice can route multiple numbers to a single device. You have to point each one to a separate line. Now my cellular carrier just one-uped Google. Nice!

    1. Bob Vistakin

      Re: Nice!

      And having come this far with Google Voice, and also controlling the OS on 90% of the worlds smartphones, Google will surely just sit back and say, "gosh, looks like we're beat, goddamit!".

      1. Graham Dawson Silver badge

        Re: Nice!

        Or they might announce that Google voice is just a beta and is being discontinued in a month.

      2. RyokuMas

        Re: Nice!

        ... or they might manipulate their search results to bury information about it...

  2. Number6

    Oh good, I've been considering a dual-SIM phone but perhaps now I won't have to.

    1. handleoclast

      Dual SIM

      The T-Mobile thing provides some of the advantages of dual SIM. But not all of them.

      If you have a dual SIM phone with T-Mobile and some other MNO, if T-Mobile goes down you can still make calls (and use data if you have data plans for both SIMs). With this scheme, if T-Mobile goes down then you're fucked. With dual SIM if you're in an area that T-Mobile doesn't cover you can still make calls through the other MNO. With this scheme if you have no T-Mobile coverage you're fucked.

      Which is why I have a dual-SIM phone with EE and Three. One dies, I can still use the other. If I'm out of coverage of one, I can still use the other.

      Well, that's what I thought until they did engineering work on my nearest mast. Which took out both EE and Three for a few hours. Sometimes mast sharing has disadvantages...

      1. Anonymous Coward
        Anonymous Coward

        Re: Dual SIM

        I have a dual SIM phone too but for a different reason. One of my SIMS is only turned on when I want to receive calls from the people that know that number. Digits won't help me with this.

  3. Kevin McMurtrie Silver badge

    App versus battery

    During the beta, activating DIGITS deactivated your number from cellular service so I didn't sign up. It will be interesting to see if they've solved that. The problem is that phone makers are cheating on battery life claims by turning off everything except the GSM radio. Push notifications are very delayed or may not work at all. (These landfill phones don't ring on pure LTE networks either)

    1. JetSetJim

      Re: App versus battery

      It's basically a SIP call - your number isn't really deactivated, as your IMSI will be used to track you as you move around the network - sounds like they just have a lookup table that routes voice calls to you via the SIP service that notifies all registered appliances that you have an incoming call. All that happens here is that a SIP paging message is transmitted to those end-points, and the mechanisms needed to instantiate bearers to a particular device are invoked as needed - e.g. same as for when you get a notification that you have an email on your phone - typically a push notification for services such as Google.

      T-Mo may be the first mobile provider to offer it, but it's been around for a while - I can receive calls on several mobiles for all calls to my home number, and have done for 2 years - and I'm pretty confident that the feature was baked into SIP at least 15 years ago.

      1. David Beck

        Re: App versus battery

        JetsetJim is right.

        I've been doing this with my much maligned Vonage acct since 2005. Moved to Vonage UK a few years ago with virtual US number and receive calls on UK mobile, wife's rings too. Outgoing via Vonage app for int'l calls. Haven't had a phone plugged into the Vonage box for years. Or the box plugged in for that matter.

      2. Anonymous Coward
        Anonymous Coward


        Back in 2010 I was able to do this with the non geographic numbers that i pushed to a SIP enabled PBX

        there was a mini pbx in the telecom providers sip enabled non geo number system that i could use to do different types of routing before it even got to my on premise PBX.

        allowed for DR scenarios and easy routing changes based on rules.

  4. Andrew Jones 2

    This is presumably using the Next Gen network since this is one of the many things covered on the GSMA site and ties in with RCS.

  5. Adam 52 Silver badge

    What's the betting that the App will want permission to everything and come with a whole load of terms and conditions that say T-Mobile's can abuse them to their heart's content?

    1. JetSetJim

      The app will need permission for the following:

      a) access contacts - so that you can dial from your contacts, or add someone to them from the app

      b) network access (wifi & mobile) - so that the call can progress over a data bearer on an available technology. They may abuse this by also bundling enhanced purchasing suggestions in informative sub-windows of the app

      c) at a stretch, location, but this should really be looked after by the mobile network infrastructure

      To offer a more complete solution, it may ask to be able to receive and send SMS/MMS, use the camera (particularly if video calls are supported), and store media files. Potentially, to guarantee access to 911 facilities, it may require the ability to make a phone call (via cellular).

  6. Anonymous Coward Silver badge
    Paris Hilton

    So innovative

    I mean nobody ever managed to work out how to clone a phone in the analogue 1G days of mobile phones.

    No, I definitely didn't know anyone who had the same phone number ring their car phone as well as their handportable at the same time.

    I must've been dreaming all of that.

    All that is old is new again.

    1. JetSetJim

      Re: So innovative

      It's not cloning, it's registering one or more devices to be notified of incoming calls and to be able to handle those calls. Those devices may well be on another service providers network, and have their own contracts.

      1G was an awfully insecure system, as everything was readily interceptable by any device in the network - which is why that worked. The same technique would not work from 2G onwards. However SIP was invented to support VoIP calls, where a central server keeps a record of subscribers to a service, and attempts to notify all registered subscribers of events related to that service. In that way, multiple different devices, on multiple networks, can register to receive calls to an IP phone number, and the IP phone service provider will attempt to notify all subscribed devices and establish IP bearers (not voice circuits) to those devices that respond.

      Google and Apple like it cos it moves the operators one step closer to being a dumb pipe, this is another attempt to put the brakes on that on T-Mo's part.

      1. Number6

        Re: So innovative

        Google and Apple like it cos it moves the operators one step closer to being a dumb pipe, this is another attempt to put the brakes on that on T-Mo's part.

        They need to adopt the approach slowly being forced upon OpenReach in the UK - infrastructure provider (pretty much the dumb pipe) terminating at the telco/ISP of your choice. So T-Mobile would morph into two parts, the airtime provider and the content provider. It would be even better if the cable operators could be forced to do the same, so you could deal with the part that provided an internet pipe and had them route packets to your choice of ISP as the end point. I use none of the added services of my ISP, they are just a dumb pipe to the internet.

  7. verno

    I wonder how WhatsApp will cope with that

    It's still tied fairly tightly to your phone number I believe?

    1. David Beck

      Re: I wonder how WhatsApp will cope with that

      For me WhatsApp used the SIM number of SIM1 (dual SIM phone). What goes out as caller ID depends on dialer. So even though my phone rings when any of four numbers are called, two UK and two US, WhatsApp only cares about the one.

  8. Anonymous Coward
    Anonymous Coward

    need it in the UK

    so when will this come to EE in the UK so i can ditch my second handset / dual sim phone.

  9. Cuddles

    How does it work?

    "The system works through an app (Android and iOS) or a downloaded application (MacOS or Windows). ...just under half used a browser on their PC."

    The system works through a downloaded application, but half of users somehow managed to use a browser instead? I mean technically a browser is an application, but that's certainly not what the first part of the quote implies. If it's usable through a (presumably platform and browser agnostic) web interface and not just a separate installed application that's a pretty important point to mention - it's the difference between being able to use it virtually anywhere at any time, and only being able to use it on my own PC that I have install rights for.

    1. Z80

      Re: How does it work?

      There's a web site that'll work with a Chromium-based browser and a Mac and Windows app. The Windows one installs to AppData\Local so shouldn't need admin rights.

      Amazing what you can find out within about 1 minute of doing a Google search for T-Mobile Digits.

  10. Anonymous Coward
    Anonymous Coward

    multiple phones on same number

    My basic question was: how can I have two or more phones with the same number. Some magic app that doesn't need another sim card, or only on WIFI? This answer was not that easy to find. Turns out they will send a second SIM for free if you sign up for that option and up to 5 sims, at some additional cost.

  11. PNGuinn
    Big Brother

    Just one little unimportant question - to start with


  12. BryanFRitt

    Blackberry OS computer texting

    "Send texts from a computer"

    Blackberry OS can already do this. Texting/typing from computer is much faster than texting/typing from a phone. (assuming one can touch type)

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