The group spent the subsequent few years testing the Network Embedded Computing Group's wireless sensors in small deployments within Microsoft's multiple data centers. Eventually, it deployed a full network in several locations at the Seattle-based company.
The system consists of small, battery-powered devices known as Genomotes. There are two types of Genomote—slave and master—that are assembled together to create a wireless
sensor node that directs data to a back-end system so Microsoft can monitor its data centers in real time and locate any hot spots.
|
|
Michael Manos
|
"If the temperature exceeds certain thresholds, the servers will suffer," Zhao states. "It would impact the performance of Microsoft's Internet services."
Slave Genomotes contain sensors that measure temperature and humidity every 30 seconds, then upload that data to a master Genomote via a cable connection. Master Genomotes, meanwhile, function similarly to certain types of
RFID tags, and communicate via a 2.4 GHz signal complying with the IEEE 802.15.4 standard (the same standard on which
ZigBee is based), to create a mesh network, transmitting information from one to the next until they reach a
base station consisting of a receiver connected to the back-end system via an Ethernet cable. If there is a problem with one base station, the system is designed to enable the transmission to continue on to a working base station.
Zhao's group attached a master Genomote, along with several slave devices, to the front or back of each server rack. "A typical configuration involves three slave sensor nodes," he says, "located at the top, middle and bottom of a rack, and attached to a master node that wirelessly communicates data to other wireless nodes." Microsoft declines to reveal how many of its data centers currently utilize the technology, nor what percentage of racks are fitted with Genomotes in the data centers in which the technology has been deployed.