Have you heard the one about IoT network tech that uses SIM cards?
Thingstream reckons USSD is talking thingies' future
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 firm's biz development veep, told us, this protocol is baked into every mobile network operator's "core SS7 network".
"It's the messaging that handshakes your phone when you arrive in a new country and gets you onto the network, all that kind of stuff that no one knows happens," said Hamilton. "There's only a few consumer uses of it."
Thingstream's parent group, Myriad, includes companies that have a lot of experience with USSD-based products. Indeed, one product described by Hamilton used USSD to provide "messaging technologies to the mobile carriers directly and to enterprises such as banks". This, he said, "was the starting point which got us thinking around IoT and a new type of bearer in the GSM spectrum".
Most of Thingstream's customers so far appear to be agencies and companies keen to deploy low-profile tracking devices that report back to base using GSM networks, though Hamilton would not be drawn further: all he would say is that the firm has "sub-100" customers.
USSD is a signalling protocol built into GSM. Hamilton explained: "There's a menu system you can use on your (pre-paid) phone, some networks offer the *#100# type codes. That's using USSD messaging. When you type in that command, it actually makes the phone phone another computer. During that phone call – effectively it's like a voice call – it's phoning the network, it's keeping the connection open.
"It sends a message with that code which the server side knows: 'ah, you need the balance for your top-up, I'll give it to you immediately.' That displays on your screen and it displays inside something called a microbrowser, which is embedded on everyone's phones."
Hamilton said Thingstream looked more closely at USSD and realised that the protocol allows messages of "around 182 characters; that's around 160 bytes. Most IoT sensor applications for sure are [using] far less than that." The internal conversation then ran along the lines of "so why don't we think about developing a solution that would leverage that technology?"
When comparing it to Sigfox, LoRa and other IoT connectivity technologies at El Reg's invitation, Hamilton also noted that the advantage of USSD as he sees it is that it allows two-way comms, rather than the broadcast-only capability of most of its rivals.
Their USSD product works through roaming-enabled SIM cards. Rather than using 3G or LTE data, however, Thingstream just uses the 2G USSD capability. "In this instance USSD is playing in that voice layer, it needs a lot less energy, there's [fewer] capacity challenges when you're going along a motorway, tracking drugs or whatever."
Thingstream is an interesting prospect that has the distinct advantage of using already-deployed technology and funnelling a decent chunk of revenue towards mobile networks, thanks to its SIM-dependent model. It avoids the problem that LoRa and Sigfox have, which is the need to deploy a dedicated network over a suitably large area – and in LoRa's case the user then has to find enough technical people to run that network. If it achieves significant takeup, it will be one to watch. ®