Wi-Fi Alliance Critiques Recent GE White Paper Comparing Wi-Fi and Other Wireless Technologies

December 20, 2010 by Jeff Shepard

According to the Wi-Fi Alliance a recent white paper authored by the General Electric Company (GE) comparing the power efficiency of Wi-Fi and Zigbee technologies in home Smart Grid applications is flawed, resulting in inaccurate findings.

What follows is the Wi-Fi Alliance critique of the GE paper:

"The report, released on December 9, 2010 and titled, "Energy Efficiency Comparisons of Wireless Communication Technology Options for Smart Grid Enabled Devices" compares Wi-Fi and ZigBee in home Smart Grid applications, focusing on power consumption as the primary evaluation criterion. The report bases its conclusion on measurements of a single implementation each of Zigbee and Wi-Fi, using Smart Energy Profile 1.0.

"The evaluation was based on old technology and tested only one implementation.

"The evaluation that formed the basis for the conclusions in the paper was conducted using ZigBee Smart Energy Profile 1.0, an older protocol which lacks key technical features, such as cyber security and IP communications, now specified by the federal government for Smart Grid use.

"Moreover, the single tested Wi-Fi implementation in the study is based on an 802.11b chip, based on ten-year-old Wi-Fi technology. Wi-Fi CERTIFIED – technology based upon 802.11n will be very widely used in Smart Grid applications, and is already used in millions of households around the world. In fact, Wi-Fi offers a range of technology options, including 802.11a, g and n, that suit the diverse range of Smart Grid applications, and none of these technologies was tested.

"The study’s design leads to inaccurate conclusions on power efficiency.

"Because the evaluation was based on old technologies, its conclusions present an inaccurate characterization of the energy efficiency of both ZigBee and Wi-Fi technologies and cannot be used to draw generalized conclusions about the state of Smart Grid communications technology today.

"Implementations of any technology using Smart Energy Profile 2.0 – the federally-specified implementation for the Smart Grid – will have increased power consumption compared with the version of the protocol which was tested, because of the additional data transmission requirements inherent in Smart Energy Profile 2.0. It should be noted that 802.11n, the current generation of Wi-Fi technology, incorporates more efficient data transmission and more sophisticated power-saving mechanisms than 802.11b, and may perform better in an energy efficiency evaluation. When evaluated using Smart Energy Profile 2.0 the differences in energy consumption between Wi-Fi and ZigBee could be much smaller.

"The study’s limited scope excluded important criteria in which Wi-Fi has key strengths.

"A recent and significantly more comprehensive Association of Home Appliance Manufacturers (AHAM) study, available here, concludes with a leading ranking for Wi-Fi as the communications protocol technology of choice in smart home appliance applications because of its range and throughput benefits, power management, established certification ecosystem, significant installed base, and more.

"Already the network of choice in an estimated 201 million households worldwide, Wi-Fi brings a variety of features unmatched by other technologies, including whole-home coverage, IP-based communications, industry-standard security protections, and advanced power management mechanisms that meet the federally-specified requirements of smart energy applications.