In the fast-paced world of IoT communications, it can be difficult to get a clear picture of what’s new, what is no longer relevant, and just how far network technology has come. For a long time, 2G satisfied the desires of most early machine-to-machine applications, with a low transfer rate, enough power to send larger packets, and a secure channel with limited interference from other devices.
This all changed once smartphones came along, leading operators to focus on higher-capacity bandwidth to satisfy consumer demand, and recently there has been moves towards shutting down 2G and 3G bands completely. In the US AT&T have shut down their 2G network and will not activate new 3G connections, Verizon will not activate new 2G or 3G devices after June 30th, and T-mobile are limiting 2G service just for M2M devices and shutting down their 1900 Mhz 3G spectrum for LTE.
Legacy devices are where 3G will serve its lifespan, as many remote or mission-critical devices have been deployed on the 2G or 3G bands and need to remain in the field, untouched, for decades. Many will choose to stay on 3G for the short time it has left (no US operators have committed to 3G beyond 2021), using intelligent switching technology to update their connectivity over the air, but the wholesale shift to LTE is inevitable. By moving to an LTE technology now, M2M companies can avoid having to replace their devices again when 2G and 3G technologies are no longer supported, and reap the benefits of a much more sophisticated and efficient network band.
What’s Next for IoT Comms?
The majority of IoT devices need a combination of low power and a wide coverage range, so that they can send tiny packets from a remote location without needing their batteries changed for up to 10 years. LPWAN (low-power wide-area network) technologies such as Sigfox, LoRaWAN and RPMA that operate on the unlicensed sub-GHz spectrum have emerged to fill this niche – but with the refarming of 2G and 3G, what will happen to those applications that need the reliability of licensed communications? This is where LTE’s efficient use of spectrum comes in to accommodate a wide range of IoT/M2M use cases, making it more than just a fast version of 3G. LTE uses all of its bandwidth by hosting different technologies that fit between other communications, so there is little or interference from higher energy communications.
LTE Category 1 (or Cat-1) was intended as an LTE alternative to broadband when it was standardized in 2015, but with performance levels slightly less than 3G, Cat-1 is more likely to replace 3G for IoT use once that band has been sunsetted. Cat-M also uses existing LTE infrastructure, but caps its bandwidth to only 1Mbps, meaning that it can easily host 2G traffic (leaving higher bandwidth IoT devices for Cat-1), with the advantage that the module cost is also considerably reduced – a huge benefit to users with a large fleet of IoT devices already deployed in an LTE coverage zone.
NB-IoT (or Cat-NB1), the other most deployed cellular low-power standard globally, uses DSSS modulation to spread its signal, and only operates on very narrow LTE guard bands, meaning it has more initial costs to deploy for the cell networks themselves. Cat-M and Cat-1, are already supported throughout the US by AT&T, Verizon and T-mobile (Cat-1 only), and are expanding into leading IoT regions like Latin America as well. NB-IoT is being deployed in late Q3 firstly by T-Mobile and then will be followed in 2019 by Verizon and AT&T.
Cat-M is therefore a very attractive option for applications that want the security and reliability of licensed spectrum, without missing out on the low-power revolution, and for those that need more speed without relying on the limited lifespan of 3G, Cat-1 is the answer.
What’s Best For Me?
The IoT is filled with applications of all sizes, with different power requirements and data consumptions, so the answer to ‘which one is best’ depends on your needs. Pod is an agnostic connectivity provider, so we’ll help you find the best fit for your business, without pushing one network technology over another.
3G will soon be sunset along with 2G, and will only support those applications with legacy devices that will have to be replaced when their lifespan is up. For the vast majority of IoT applications, however, LTE can satisfy the need for high or low bandwidth, and can offer stable, reliable communications on a licensed band without the risk of interference that unlicensed technologies face.
Cat-M and NB-IoT offer the best alternative to unlicensed LPWAN technologies, and Cat-1 for higher bandwidth applications that don’t require speeds of more than 12 Mbps. The main advantage of all of these LTE technologies is that they are expected to be around for more than 10 years which allows you to take action now to future proof your devices. IoT companies should consult an IoT expert before making any decisions around connectivity, but one thing is certain: IoT-specific cellular connectivity is a game-changer, and LTE technologies are leading the charge.