er 40 feet. "We were in a lab environment with a lot of high-power equipment that generates interference," says researcher Jason Hill, who received his PhD in electrical engineering and computer sciences from UC Berkeley in May. "If we went outdoors and had direct line of sight between the two motes, we could realistically transmit about twice the distance we did indoors." Spec also includes hardware accelerators to help the core pieces of TinyOS run more efficiently. The accelerators allow data encryption to be performed by the hardware, which is thousands of times more efficient than performing the same function in software. The mote's radio transmitter uses 1,000 times less power than a standard mobile phone. In addition to the chip, Spec requires an inductor, an antenna, a 32-kHz watch crystal, and a power source. The researchers note that these components would add little to the mote's size. Several companies are already developing millimeter-scale batteries that could power a commercial version of Spec. CONNECTIONS IN THE AIR-WIRELESS TECHNOLOGIES Besides its academic and commercial potential, Spec has generated inter- est from the military for possible uses on the battlefield or to monitor troop movements. Pister says he plans to develop Spec into a commercial product within the next year. He notes that the finished product, which will include the battery and casing, will likely be about the size of an aspirin. 3.9 COLLABORATIVE SENSING Large-scale, distributed and sensor-rich wireless networks can be used to track physical phenomenon, including multiple moving objects such as vehicles or animals. Potential applications include traffic control, battlefield target track- ing, security, and monitoring of wildlife, environmental pollutants, and infra- structures such as power and telecom grids. Scientists in the embedded collaborative computation group of Xerox's Palo Alto Research Center (PARC) are exploring problems in information processing, communication, storage, and routing in environmentally based smar