rk (PAN): - A short-range network, usually wireless, that provides a connection between two or more devices, for example, linking a PDA to a computer in order to synchronize data. Photon: - A particle of light. Photonic circuit: - A circuit that uses light rather than electricity. Photonic crystal: - A credit-card-thick stack of optical filters. Picture phone: - AT&T's video telephone technology, introduced at the 1964-1965 New York World's Fair. Piezoelectric: - Material that moves when placed under an electric voltage. Plain old telephone service (POTS): - Ordinary telephone lines and equipment. Polymer: - A substance made of repeating chemical units or molecules. The term is often used in place of plastic or rubber. POTS: - See Plain old telephone service. Ordinary telephone lines and equipment. Project Oxygen: - A Massachusetts Institute of Technology project for replac- ing discrete telecommunications and computer devices with a ubiquitous- often invisible-infrastructure. Protocol: - Rules pertaining to the transmission and reception of information. Quantum cryptography: - Technology for encrypting data that draws on inher- ent properties of photons. Radio frequency identification (RFID): - An asset tracking and data collec- tion technology that uses electronic tags to store identification data and a remote reader to capture information. RBOCs: - See Regional Bell operating companies. Reader: - A device that obtains data from a source, optically, electrically, or via radio or infrared signals. Regional Bell operating companies (RBOCs): - One of the original Bell System operating companies. GLOSSARY RFID: - See Radio frequency identification. SALT: - See Speech application language tags. SDR: - See Software-defined radio. Second-generation services (2G): - Digital mobile phone services. Sensor: - A device that detects a real-world condition, such as heat, motion or light, and converts and relays that information to a computer. Smart: - Intelligence built into a device or system. Smart phone: - A telephone wit