Nuts and Volts - June 2014

Embedded micros in each vehicle will analyze the data and provide feedback to the driver. Even automatic braking can be deployed in close-call situations.

Then, there is vehicle-to-infrastructure (V2I) systems that let vehicles communicate to nearby roadside nodes in a network that can supply traffic, weather, road conditions, and other safety information automatically. These services will use a Wi-Fi type of wireless technology called Dedicated Short Range Communications (DSRC) in the 5. 9 GHz band for communications. The Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) believes that up to 80% of all collisions could be avoided with such systems. Look for them to become standard on vehicles in the future.

WHAT WIRELESS WORKS FOR M2M AND IOT?

Almost any short-range wireless technology will work for M2M or Io T, but some common ones are emerging. For example, cellular connections make up about 40% of all M2M applications. A cellular modem module like that in Figure 4 is embedded into the device to be monitored. An accompanying embedded microcontroller runs the applications. Older 2G technology like GSM and GPRS cellular can be used, but with some carriers planning to phase out the older GSM 2G networks it makes GSM and other older methods a poor choice. Most new systems will use the faster 3G WCDMA and 4G (LTE) cellular modems despite the fact that most M2M applications require mostly low speed (<500 kbps) data rates. Most of the major cellular carriers like AT&T, Sprint, T-Mobile, and Verizon offer M2M services.

Wi-Fi is another popular connection technology. Since it is available in millions of hot spots and home networks everywhere, it is a likely choice for Io T. Wi-Fi modules are easy to build into most products.