Author(s): Raghu Gopal
Category M is a flavour of LTE optimised for low-cost, low-power cellular connectivity applications. Standardised by 3GPP like the rest of the LTE family of standards, category M is all about enabling a network of connected things. (The "M" indicates the machine-centric intentions of the spec.)
With category M, the LTE specs have been modified to use a fraction of the energy needed by other LTE devices such as phones and tablets. This means connected objects could go as long as 10 years on a single charge. The technology is particularly practical for adding connectivity to generally hard-to-reach places. Furthermore, the standard is engineered to penetrate walls which are up to 8 inches thicker than those that standard cellular signals can penetrate.
Operators are now readying commercial support for the standard by deploying LTE-M networks, hoping to spark rapid commercial growth in the Internet of things.
This week, AT&T announced that it will launch LTE-M coverage in the US by the middle of 2017. The carrier also said it expected to expand coverage to Mexico by the end of the year. The launch follows the successful completion of a pilot started in October 2016 at AT&T Labs in San Ramon, California with several partners.
The LTE-M network has a top speed of about 1 Mbps upstream and downstream, and a range of up to 100 kilometres (60 miles). In the age of HD video streaming, this sounds stingy, but the thin bandwidth is generally sufficient for applications that usually need to transmit only small amounts of data, such as location information or the amount of water registered in a meter.
The headline focus on the Internet of things has been on connecting consumer products such as lights, watches and refrigerators to the Internet. In reality, the more immediate and tangible benefits will be for enterprise uses such as monitoring meters, tracking fleets and cargo, and maintaining machinery. For example, PepsiCo is trialling LTE-M to collect usage data from soda fountains. Consumers can dispense their own blends of drink from these fountains, and PepsiCo uses sensors to keep the fountains stocked and also gain insights into popular blends.
AT&T is one of several mobile operators around the global preparing to add support for LTE-M to their networks. Others include Orange in France and SoftBank in Japan.
Despite all the talk about the Internet of things, without a robust and standardised network infrastructure, the full opportunity will not be realised for lack of economies of scale. LTE-M is expected to be one of the major enabling technologies for connecting things, along with NB-IoT for even smaller data transmissions.
AT&T stated in its latest quarterly report that it already has nearly 32 million connected devices on its network in addition to phones and tablets. It's an impressive number and reflects AT&T's success in connecting cars and creating smart cities. AT&T's IoT machinery is in full gear and the operator is hoping to establish itself as a leader.