M2M applications will typically use the same wireless module for anywhere between five and 20 years. And right now most of them run over 2G and 2.5G networks because coverage is ubiquitous and rates have become very competitive. 

When I started covering M2M, I used to wonder why higher data rates were needed. With the possible exception of video surveillance, the apps are not bandwidth intensive and video performance over 2.5G is acceptable. So why move to 3G? And what is the justification for going to the seriously high data rates of HSPD and LTE (News - Alert)? Developing these next-gen modules and getting them certified is going to be expensive. And to complete the air interface picture, why is WiMAX in the frame?

If you believe in forward looking applications like in-vehicle infotainment, e.g. streaming video and games to kids in the back seat then you need the kind of bandwidth that LTE delivers. And running telemetry and other apps like usage-based insurance over this air interface at the same time isn’t a problem, so there is a valid business model for this sector if the concept takes off. 

From a technical perspective WiMAX (News - Alert) can do the same thing: it can handle bandwidth-intensive applications and services should be cost-effective: the operators use free spectrum. But coverage is a long way from being ubiquitous and it will stay that way since the technology was designed for urban environments, so the kids would start screaming when there’s no network coverage. Therefore, you need to use 3G as a fallback technology, but that would make the modules more expensive.

Answers

Operators are migrating to all-IP next-gen networks, both in the core and the air interfaces. They’re faster and much more efficient. Therefore, it’s more than likely that the 2G and 2.5G networks will be phased out, followed by 3G at a later date. It won’t happen anytime soon, but given those long life cycles it doesn’t make sense to develop new apps for yesterday’s wireless technologies. High-speed data may represent engineering overkill, but if the price is right it doesn’t matter. 

If coverage is available, then WiMAX is an attractive proposition for M2M. The chip sets are relatively cheap and the certification process should be less irksome than that required for cellular networks. WiMAX modules should therefore be significantly cheaper than those that employ HSPD or LTE and because the spectrum is unlicensed, the service is likely to be very competitive.   

Conclusion: WiMAX has a lot going for it when it comes to apps that don’t need anywhere, anytime access. In Europe there is growing interest in employing this air interface for advanced metering infrastructure (AMI). Other candidates include real M2M (machines on factory floors), smart grid and surveillance networks. In the U.S., WiMAX is being deployed for smart grid trials.