While many analysts are debating the definitions of M2M and the IoT, no one is debating that wireless data network applications are growing rapidly. Both Cisco and Ericsson have predicted that there will be 50 billion devices connected by 2020, up from 14 billion today.
What are these new connected devices? Many of the predicted next wave of devices will be fixed-location, sensor-based devices sending less than 500 bytes of data a day. Strategy Analytics estimates that this will account for roughly 5 billion device connections by 2022. Even more interesting is their prediction that half of these new applications will come from startup companies.
These sensor-based applications have some specific requirements, notably, 7 to 10 year battery life; modem costs under $10; network fees less than $1 per month; and indoor and outdoor ranges measured in miles, not feet.
Existing cellular networks, especially 4G-LTE networks today, cannot meet these requirements and here’s the reason: today’s cellular networks are “always on” so batteries last days not years, power requirements are ten times more for transmit and 100 times more for standby and cellular hardware and monthly service fees are too expensive.
So who and what are these new networks? The term that is emerging to describe them is LPWA (Low Power Wide Area) networks. What they all have in common is that they are very low speed and inexpensive. Why so slow? The slower the data rate, the greater the link budget, or range. This is how they get two miles from deep inside buildings to 10+ miles for outside applications.
Major players are emerging in the LPWA space with networks covering full countries. Within this model, remote devices can send in data, but data cannot be transmitted back out. We had an almost identical network in the U.S. in the 1990’s called AlarmNet. AlarmNet was built out in the major cities in the U.S. to monitor alarm panels, smoke detectors, and other security systems. What they eventually had to address is that a one-way network with non-acknowledged messages required a lot of Forward Error Correction (FEC) to increase the chance that the message gets through and is heard by the network. This clogs the network and reduces the number of devices that the infrastructure can support.
Many applications will only require one-way data transmission. If messages are critical, however, two-way is required. Two-way communication ensures that the messages get through and are acknowledged, and that you can wake up a device to make sure it is still working properly. Two-way communications also ensures the ability to control the end device, and the ability to update or change firmware or application functionality remotely.
There are several companies now in stealth mode with products that have the same long range, lower power radios with great battery life, but will also operate efficient, well-architected two-way networks.
There are still some clouds on the horizon for these LPWA networks. Several of these companies operate in the unlicensed ISM (Industrial, Scientific, Medical) bands. Because they are unlicensed, these companies can put up their infrastructure wherever they want. This makes it easier and less costly for them to build out networks than licensed networks. However, the ease of deployment of unlicensed ISM band applications will be their major hurdle. ISM band applications must accept interference from other transmitters which means the more applications or networks that operate in these bands, the more interference they must accept, which ultimately limits the number of devices that can be monitored by these new networks.
What technology will win? Stay tuned.
Edited by
Ken Briodagh
