Driving wireless M2M. Wireless M2M has become more practical because of cost reductions in wireless communications technologies, as well as advances in their performance, functionality, and reliability. The technologies include cellular approaches; IEEE 802.11; Bluetooth, generally used for short-range device connectivity; IEEE 802.15.4 low-rate, short-range networks; the Zigbee protocols ( www.zigbee.org), built on top of IEEE 802.15.4 for low-power monitoring, sensing, and control networks; radio frequency identification (RFID), which uses electromagnetic or electrostatic coupling to transmit status signals from tagged devices; and the IEEE 1451.5 wireless communication methods and data format for sensors, controllers, and actuators.
Mesh networks promise to drastically reduce M2M's power requirements and thus let remote sensors operate longer between battery changes. Mesh networks enable nodes to communicate with and pass data directly to other nodes, permitting the data to travel in short hops over long distances. Traditional networks send data from servers to individual nodes and back and thus are limited by their single-hop transmission range.
Lower costs and increased accuracy in sensors have made wide deployment easier and less expensive. "Now you can peel and stick them to any type of machine you need to monitor," said Millennial Net's Pacelle. Major cellular operators have developed services for M2M systems with rate plans that cost as little as $4.99 per month per node, noted John Andre, vice president of business development at Airdesk, an M2M systems integrator.
Andre said that for large M2M applications, integrating embedded cellular-radio modules—such as the Nokia 12 GSM or the Sony Ericsson GT48—into nodes can make sense. These modules translate and format data for transmission over wireless networks, thereby simplifying the connection to M2M systems, and are less expensive for many companies than developing their own equipment.
Using wireless M2M. Wireless M2M can be desirable for cost-sensitive deployments. In addition, wireless M2M networks let users track mobile assets like truck fleets or equipment in the field, the quantity and location of products in stock, and items in a vending machine.
Wireless M2M could also be embedded in projects where wires aren't practical, such as with sensors measuring the stress in walls or bridges.