Choosing The Right Communications Protocol

July 21, 2005

A communications protocol determines the type of signal being transmitted and how it encodes the information contained within the signal. While there are many different wireless communications protocols, three stand out for wireless sensing: Wi-Fi (IEEE 802.1), Bluetooth (IEEE 802.15.1), and ZigBee (IEEE 802.15.4). Each protocol is backed by a consortium of companies, with ZigBee gaining favor thanks to its simplicity, low cost, and low power dissipation (see the table).

Two special frequency bands have been set aside for wireless-sensor-net communications: the Industrial, Scientific and Medical (ISM) band and the Unlicensed Network Information Infrastructure (U-NII) band. However, many potential interference sources can plague wireless sensor nets, including microwave ovens and electric motors. Often, they will simply overwhelm sensor communications.

Another method of communications, RF ID tagging, requires no power in the RF ID tag for transmission. The passive technology is used for labeling and tracking materials. Message size, though, is one limitation. Present RF ID tags can hold only 96 bits of information. Work is under way to increase that amount to 128 and 256 bits.

About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.