protocols. IM: - See Instant messaging. Incumbent local exchange carrier (ILEC): - A local telephone carrier that was one of the original Bell System operating companies. Information hiding: - See Data Hiding. Instant messaging (IM): - The process of exchanging real time voice or text messages over a network. Institute of Electrical and Electronics Engineers (IEEE): - A membership organization that sets many telecommunications, networking, and computer standards. Interference: - Unwanted signals from a manmade or natural source. International Organization for Standardization (ISO): - An international standards-setting organization. Internet protocol (IP): - The network layer protocol in Internet-based networks. IP: See Internet Protocol. ISO: - See International Organization for Standardization. Joint Photographic Experts Group: - The organization that developed JPEG, a popular image file compression format. JPEG: - A popular image file compression format. See Joint Photographic Experts Group. Key: - In security, a numeric code that's used to encrypt information. kHZ: - See Kilohertz. Kilohertz (kHz): - One thousand cycles per second. See Hertz. LAN: - See Local area network. Local area network (LAN): - A computer network that serves users in a confined location, such as an office or building. GLOSSARY Local loop: - The connection between a phone customer and the phone company's office. Location-based service: - A service that works by pinpointing its user's location. Megahertz (MHz): - One million cycles per second. See Hertz. MEMS: - See Micro-electrical mechanical systems. Mesh network: - A network that provides at least two pathways between each node. MHz: - See Megahertz. Micro-electrical mechanical systems (MEMS): - Nano-sized devices that are built onto chips. Microscillator: - A miniature device for generating tunable microwave signals. Motion Pictures Experts Group: - The organization that developed MPEG, a popular video compression format. Motion tracking: - Using a video system to automatically follow 