S TDD (3G traffic shaping mobile protocol), for its 3G mobile service. A way for carriers to manage traffic to control congestion. Techniques include providing tether better QoS for particular types of traffic such The ability to connect laptop or tablet com- as video, prioritizing traffic for higher fees, puters that don't have Internet access to the and throttling traffic (decreasing speeds) for Internet via a mobile handset's Internet con- subscribers who exceed allotted amounts. nection. This is generally done by connecting the computer and mobile handset together transponder through USB ports via USB-compatible Fiber-optic transponders receive, amplify, cables. and retransmit optical signals on different wavelength channels on fiber cabling. They throughput also convert electrical signals to optical sig- The actual amount of user data that can be nals and optical signals back to electrical sig- transmitted on a telecommunications link or nals where they connect twisted-pair copper on wireless networks. Throughput does not or coaxial cabling. include headers, for example, bits used for trunking gateway addressing, error correction, or prioritizing Converts packet network circuits (such as packets with voice and data bits. T1/E1 and T3/E3), to those compatible with the Public Switched Telephone Network tier 1 provider (PSTN), and vice versa, SO that voice traffic A loosely defined term for Internet service can be transferred between IP networks and providers that own Internet backbone fiber- traditional, circuit-switched networks. optic facilities in addition to ISP services such as hosting and e-mail. Examples include trunks AT&T, Level 3, Sprint Nextel, and Verizon. The circuits (electrical or fiber paths) between telephone companies and enterprise TDM (Time-Division Multiplexing) telephone systems and between central office TDMs, such as T1/E1 equipment, save switches. A T1 is a trunk. capacity for each device that is connected to the multiplexer. This is less efficient than tuner other methods such as stat