The machine-to-machine (M2M) communications space, made up of network-connected non-cellular devices, grew 21 percent in the most recent quarter, according to analyst Chetan Sharma.

With subscriber growth slowing across the board, M2M is one area operators are keen on beefing up. In fact, the GSM Association (GSMA) and Machina Research forecast that total connected devices will grow from more than 9 million today to 24 million in 2020. And, this summer alone, we've seen a number of moves across the globe designed to better position wireless operators to capitalize on this growth.

Here's a quick recap of six ways the operators are mining the M2M market, and a few ways vendors plan to as well.

1. Deutsche Telekom's secret M2M garden
Deutsche Telekom AG (NYSE: DT) is the latest big operator vying for developer attention in the M2M space. The German operator has opened the doors to its Developer Garden to connect developers to application programming interfaces (APIs), programming guidelines and software development kits (SDKs) to build and sell M2M apps on its network. The garden serves as the central point of contact for its M2M Developer Community to exchange ideas with other developers and DT's M2M team, to build their apps and then to sell them via the carrier's Marketplace. (See Deutsche Telekom Grows an M2M Developer Garden.)

2. AT&T asks M2M customers to upgrade
AT&T Inc. (NYSE: T) revealed earlier this month that it plans to shut down its 2G network by 2017. The customers that may be most affected by this are its M2M users that don't need much more capacity to power their bursty apps and devices. AT&T is encouraging them to upgrade to a faster (and likely more expensive) 3G connection before the 2G network goes under. It could end up losing some customers in the process, which would hurt AT&T, because it's currently the M2M market share leader in the U.S., according to analyst Sharma. This could be good news for T-Mobile US Inc. , however, as it's the only carrier that has said it will reserve some of its 2G network for M2M even as it refarms most for Long Term Evolution (LTE). (See AT&T: Say Goodbye to 2G in 2017 and What 'G' Do Connected Devices Need?)

3. The China Mobile machine
China Mobile Ltd. (NYSE: CHL) is helping make its home country the biggest geography for M2M. The carrier counted 14 million connected device subscribers at the end of 2011, and Berg Insight AB says it will surpass the U.S. in absolute terms within two to three years if it continues at this growth rate. The GSMA predicts the business impact from China's connected devices will increase six-fold -- from US$116 billion in 2012 to $707 billion in 2020.

4. Frag reduction
Network fragmentation could pose a problem for companies that want to take their M2M-powered devices global, but standards bodies and the wireless operators are teaming up to ease the pain. Last month, seven standards bodies announced they're teaming up to form oneM2M focused on the technical specs to deploy M2M globally. And, a separate group of seven wireless operators said they're joining forces to reduce costs and simplify global connectivity for the devices. Now, seeing how long it takes for these huge groups to agree on standards will be the real test. (See Standards Bodies Join Forces for M2M and M2M's Magnificent Seven.)

5. Telematics speeds up in the U.S.
Wireless operators in the U.S. are paying special attention to one of the sexier areas of M2M: telematics, or in-vehicle connectivity. Verizon Wireless has staked the biggest claim so far, acquiring M2M vendor Hughes Telematics to improve connected-car features and launching a consortium of car makers interested in adding LTE to their vehicles. (See Verizon Spends $612M for a Future in Cars, Verizon Closes Hughes M2M Buy and Photos: Connected World's M2M Jam.)

6. RIM eyes M2M for BlackBerry
BlackBerry CEO Thorsten Heins is eager to license the company's BlackBerry 10 software, and he's eyeing non-cellular devices even before the software makes its way to a smartphone. Heins tells Bloomberg that RIM will extend BlackBerry 10 beyond smartphones and tablets to other areas of mobile computing, including M2M devices. (See OS Watch: RIM Revisits Licensing BB10.)

— Sarah Reedy, Senior Reporter, Light Reading Mobile