According to the Global Mobile Suppliers Association (GSA), at the end of Q1 2015 there were 393 commercially launched LTE networks in 138 countries supporting 635 million LTE subscriptions, 428 million of which had been added in the previous 15 months. GSA estimates there will be more than one billion LTE subscriptions by the end of 2015.

Three years earlier, GSA chairman, Alan Hadden, had observed: "The number of operator commitments to deploy LTE networks, announced in the 12 months following the first commercial LTE network launch, was higher than for any other mobile communications technology in the same stage of development."

The ITU, in its State of Broadband 2014 report said: "It took GSM technology 6.3 years to achieve its first 100 million users whereas LTE achieved the same milestone in just 4.2 years. The rapid growth of LTE in particular has overtaken all previous mobile technologies, and LTE is expected to grow even faster over the next few years."

Whichever way you look at it LTE is growing faster than any other mobile technology. According to the GSA, in Q1 of 2015, New LTE subscriptions outpaced 3G/WCDMA-HSPA subscriptions by 58 percent. Meanwhile, GSM (2G) subscriptions are in terminal decline. Their number fell 78.5 million in Q4 of 2014, and a further 100 million disappeared in Q1 of 2015.

The reasons carriers are rolling out LTE with such zeal are not hard to find. In much of the world the mobile device is the main internet access device, pushing up demand for high speed mobile broadband, aided by the growing popularity of video.

In addition, LTE is much more cost effective and spectrum efficient than earlier mobile technologies, especially 2G. Booz & Co has estimated the cost per Mbps of network capacity on LTE to be only one thirtieth the cost using 2G EDGE technology and a sixth of the cost on 3G (HSPA).

So it's no wonder those mobile operators that have been most aggressive with their LTE rollouts have announced plans to shut down their 2G networks and free up the spectrum for use by the much more efficient LTE. Telstra's 2G network and that of AT&T in the US will both be gone by the end of 2016 and in Singapore the Government has a set a shutdown date for all 2G networks of 1 April 2017.

When he announced Telstra's 2G shutdown plan in mid 2014, Telstra's managing director networks, Mike Wright, said: "Today 2G traffic accounts for less than one percent of our total network traffic [and] we have not sold a 2G phone for several years."

However, Norwegian telco Telenor plans to keep its 2G network going for another decade, until 2025, and is planning instead to free up spectrum for LTE and future 5G technologies by shutting down its 3G network in 2020.

CTO, Magnus Zetterberg, justified the decision by saying. "It’s better to retain 2G than 3G because all the devices today are still embedded with 2G, so you will lose out without the network. 2G is still important for the M2M market.”

Users on other networks will not be so fortunate. AT&T says it is "committed to providing clear, advance notice and communications about our 2G migration and to working closely with our customers to manage the transition," but is telling its M2M customers "quot;Ultimately [you] are responsible for planning hardware upgrades in a reasonable timeframe prior to planned network shut downs."

It also points out that by transitioning to LTE, M2M customers will be able to "enhance their applications and solutions with new features (ie video cameras for real-time streaming/records for alarm solutions, driver dash cameras for fleet trucks, etc) because of the higher speeds of the upgraded network, allowing them to better serve their customers and employees."

It's the lower latency of LTE networks compared to 2G networks that enables support of real-time services, but LTE also has other benefits over 2G and 3G for operators of M2M services. For example, it allows them to offer services with different grades of service, and charge premium prices for premium services.

That's the situation with today's LTE M2M devices, which operate on the same LTE standard as every other LTE device: smartphones, mobile broadband dongles and other such devices. It's a standard designed to provide high speed mobile broadband, not specifically to cater for the needs or M2M applications, but that is about to change.

In short, LTE-based M2M technology has a very bright future.