back to article Have you heard the one about IoT network tech that uses SIM cards?

Another Internet of Things upstart has nudged its way into the limelight – and Thingstream reckons its "MVNO for IoT" connectivity offering will compete against established players Sigfox and LoRaWAN. Thingstream's product is built on the USSD (Unstructured Supplementary Service Data) messaging protocol. As Neil Hamilton, the …

  1. 2+2=5 Silver badge


    > Hamilton said Thingstream looked more closely at USSD and realised that the protocol allows messages of "around 182 characters; that's around 160 bytes.

    I'm confused. There's already a protocol that allows about 160 bytes of data to be sent to and from a phone. It's called SMS.

    1. TRT Silver badge

      Re: Eh?

      Slightly different way of doing things, though. The SMS payload is one way, the control structure is two way. USSD has two way payload space. The difference is SMS BALANCE to 450, wait 5 seconds, receive a SMS text back with the information. Dial *#100# and the balance appears immediately and is displayed on screen, not saved.

      There are already, and have been for ages, GPS trackers that send a SMS with their location information. There aren't any, that I know of, that use USSD to do that. I think this is a promising technology. Not sure how long it will last given the roll out of consumer led 3G/4G/5G etc.

      1. fuzzie

        Re: Eh?

        SMS and USSD use the same signalling channels, but you can view them as TCP vs UDP, i.e. USSD is session-based at the GSM layer. SMS-based apps have to roll their own if they require something more than a simple single request/reply.

        That very same channel also carries "cell broadcasts". Popularly, it was a novel people used to display cell location name or even, as MTN did for a while, cell-contention-based call discount rates.

        Another upside for IoT devices using good old 2G GSM, is that those chip sets are ridiculously cheap and very miserly on power compared to the newer generations.

    2. Jenks

      Re: Eh?

      SMS is only 140 bytes, USSD is 160. They both use a default 7 bit alphabet, but can be configured to use UTF-16.

    3. J. R. Hartley Silver badge

      Re: Eh?

      Shirley the point is that sending USSD messages is free, but SMS isn't? (At least without a contract)

    4. 2+2=5 Silver badge

      Re: Eh?

      @ TRT & fuzzie

      Thanks for your helpful responses.

  2. Anonymous Coward
    Anonymous Coward

    agencies and companies keen to deploy low-profile tracking devices

    I take it "low profile" here means "extremely sneaky, if not quite outright underhanded" rather than "not requiring a lot of space/resources in the device".

    1. Anonymous Coward
      Anonymous Coward

      'extremely sneaky, if not quite outright underhanded'

      You know its coming.... What's next? Faraday Caging our homes!

      1. Anonymous Coward
        Anonymous Coward

        Re: What's next? Faraday Caging our homes!

        I'm not sure that'll be necessary. Two half-built blocks of flats in line of sight to the nearest phone mast has just almost completely killed our mobile signal at home. Another block will be underway shortly.

  3. Mike007

    What is the advantage over SMS/GPRS? I get the feeling they are taking advantage of the fact that these sorts of messages are normally used internally by carriers, so aren't billed.

    Correction: Weren't billed prior to this story being published.

  4. Karlis 1

    So, yeah, they have, effectively, discovered SMS - which happens to be a payload on top of this protocol IIRC (my leet ss7/smsc skills are an honest decade out of date now).

    Good on them. If they'll manage to secure shedloads of cash on the basis of this I'll be quite sad - and looking for the names of investors to sell them a goundbreaking concept of making things that go round - well, round.

    (But actually - do really GOOD ON THEM! Somebody actually does something sensible as opposed to hur-hur-new-networks-for-iot-wanking that even bigger names like vodafone has fallen prey to).

  5. AnonymousCoward

    Move along, nothing new to see here

    One of the key points about USSD is where the server you are talking to is sited. It typically lives within the core network of your connectivity (SIM) provider and is, therefore, hard to get at/set up/manage. These guys can make USSD easy for you because they can host the server in their network usually using the ICCID to identify which of their customers the SIM belongs to and redirecting the request to that customers server so it can do specific things for that customer.

    Its not a new idea but I guess they are dressing it up in a more usable API which has some value. It might make it possible to use cheaper modems as you don't need to support UDP/TCP but to be honest the core GSM protocol support will dwarf that for resources anyway.

  6. bobajob12

    chipset cost

    I'm curious if this will work out financially - isn't a wifi chipset and a basic TCP/web stack an order of magnitude cheaper than an LTE/3G chipset with an IMS (SIP) or SS7 stack?

  7. IglooDude

    "Rather than using 3G or LTE data, however, Thingstream just uses the 2G USSD capability."

    I feel like I'm missing something - aren't cellular carriers turning down 2G left and right?

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