M2M communications infrastructure continues to evolve. The announced shutdown of Telstra’s 2G (GSM) network is driving users of 2G M2M devices to search for alternatives and solutions. Some industry experts advocate the need for new networks specifically for M2M/IoT. Others see existing cellular as the best option, however in the past cellular has been not well suited for low bandwidth low cost characteristics of M2M/IoT applications.
Alternative cellular networks are being established to specifically support M2M/IoT, offering low cost wireless M2M with cheap data rates and low cost hardware for low bandwidth data throughput. Initiatives launched by Weightless (U.S.) SIG and SigFox (Fr.) and others offer M2M/ IoT solutions incorporating coverage, battery life, module cost and simplicity of operation that are claimed to improve greatly existing cellular networks. These new networks utilize unlicensed frequency bands but with some risks such as interference, proprietary and non-standard nature of the systems, and they are not always bi-directional. They do offer excellent power savings and are good for private deployments.
Cellular networks are turning off 2G (GSM) networks to re-farm the spectrum using 3G and LTE technologies. LTE in particular can be far more efficient and provides much higher bandwidth at lower prices. We are seeing 3G and LTE technologies being promoted for M2M/IoT applications but are these networks suitable for M2M use?
Most M2M applications do not need the higher bandwidth of LTE and 3G. Even in the envisioned IoT, with huge amounts of data produced by billions of sensors, bandwidth requirements per device are tiny. The new LTE networks can provide low data costs and the air interface can be split into several narrow band channels of different bandwidth. This allows bandwidth to be assigned in a very flexible way that could make it ideal for M2M and IoT applications.
According to Sierra Wireless, technologies that leverage existing networks make the most sense and they see 4G/LTE becoming a technology of choice for M2M deployments. Sierra Wireless believes that cellular connectivity will play a key role in the Internet of Things (IoT), and has been working with other hardware vendors and network carriers on the recently unveiled LTE-M (LTE for M2M). LTE-M will offer low power consumption (up to five years for a device running on AA batteries), easy deployment and interoperability, good security and mobility, low overall cost, and excellent coverage. We should see modules with this technology start to come to market in 2016. LTE-M is likely to evolve further with discussion on including local mesh networking, very low cost modules (under $5), very long battery life (more than 10 years) and low data rates with two-way communication.