Mobile operators believe their networks will enjoy a second life as the backbone of the internet of things, but a French startup Sigfox begs to differ. It’s building a dedicated network in France designed to connect objects and machines, not people. So far, carriers’ confidence is well founded. Mobile operators are using their 2G and mobile broadband networks to connect everything from jukeboxes to ice machines, and as mobile phone penetration nears 100 percent, a good deal of carrier growth is dependent on these new machine-to-machine (M2M) subscriptions.
But a French startup named Sigfox is challenging that accepted wisdom. Sigfox business development chief and Internet of Things of evangelist Thomas Nicholls said that cellular networks were meant to connect humans, not objects. Sigfox is proposing to build an alternate wireless network dedicated solely to linking together the Internet of Things.
Our mobile phones are always on and ready to receive and make phone calls, update our Facebook and Twitter feeds or download new email, but the majority of objects linked to the network will connect rarely. A GPS tracker in a vehicle or shipping container may send out its coordinates just once a day. A smart meter may link back to its utility company’s servers once a week. Many of the sensors being embedded in devices from vending machines to security cameras only transmit when something goes wrong, meaning a M2M module may wait months if not years between connections to the network.
Sigfox has developed a wireless architecture using ultra narrow-band modulation techniques that can theoretically support millions of devices with only a handful of network transmitters. Using the unlicensed frequencies commonly used for baby monitors and cordless phones (868 MHz in Europe and 915 MHz in the US), Sigfox SAYS IT can provide the same coverage with a single tower that a cellular network could provide with 50 to 100 cell sites. Sigfox is building a network covering all of France with 1,000 transmission sites, and Nicholls estimates that the company could do the same in the US with 10,000 transmitters. The radio modules embedded in objects are about the size of two thumbnails, and they transmit at power levels 50 times lower than their cellular M2M counterparts. Such low consumption levels mean that objects that normally have no external power supply could remain connected for as a long as 20 years before their module batteries would require recharging.