rcentage of bits received in error in a advanced mobile protocols. Many countries transmission. are re-farming spectrum originally used only for older second-generation services to newer blade fourth-generation technologies. Circuit boards are often referred to as "blades" when they are dense, such as when they have backbone many ports (connections) or software for a A segment of a network used to connect specialized application such as security. smaller segments of networks together. Back- bones carry high concentrations of traffic Bluetooth between on and off ramps to networks. A set of standards for special software on low- backhaul cost, low-powered radio chips that enables devices to communicate with one another A term used mostly to describe the links between antennas at base stations and mobile over a short-range wireless link. Bluetooth central offices, and services in the cellular eliminates cable clutter between computers networks core. Traffic and signaling informa- and peripherals in offices and supports wire- tion is backhauled from where it enters the less headsets for mobile handsets. network to the mobile core, and vice versa. BOC (Bell Operating Company) bandwidth One of the 22 local Bell telephone compa- The measure of the capacity of a communi- nies owned by AT&T Corporation prior to cations channel. Analog telephone lines mea- 1984. Examples of Bell Operating Com- sure capacity in hertz (Hz), the difference in panies are Michigan Bell, Illinois Bell, and the highest and lowest frequency of the chan- Pac Bell. Bell Operating Companies are now nel. Digital channels measure bandwidth in part of AT&T Inc., CenturyLink, and Verizon bits per second (bps). Communications. Glossary border elements BTA (Basic Trading Area) Another name for media gateways. See also A relatively small area in which the FCC media gateways. allocates spectrum. There are 491 basic trad- ing areas in the United States. bps (bits per second) The number of bits sent or received in one CAP (Competitive Access Provider) second. 