| TACS |
Total Access Communications System |
|
| TAMS |
Temporary Mobile Station Identity |
|
| TCH |
Traffic Channel |
A logical channel that allows the transmission of speech or data. In most second generation systems, the traffic channel can be either full or half-rate. |
| TCH/F |
Traffic Channel - full rate |
|
| TCH/H |
Traffic Channel - half rate |
A traffic channel using half rate voice coding. |
| TCM |
Trellis Code Modulation |
A type of channel coding that, unlike block and convolutional codes, provide coding gain by increasing the size of the signal alphabet and use multi-level phase signalling. |
| TCP |
Transmission Control Protocol |
TCP/IP is the standard communications protocol required for computers communicating over the Internet. To communicate using TCP/IP, computers need a set of software instructions or components called a TCP/IP stack. |
| TDD |
Time Division Duplex |
A duplexing technique dividing a radio channel in time to allow downlink operation during part of the frame period and uplink operation in the remainder of the frame period. See also duplex. |
| TDMA |
Time Division Multiple Access |
A technology for digital transmission of radio signals between, for example, a mobile telephone and a radio base station. In TDMA, the frequency band is split into a number of channels which in turn are stacked into short time units so that several calls can share a single channel without interfering with one another. Networks using TDMA assign 6 timeslots for each frequency channel. TDMA is also the name of a digital technology based on the IS-136 standard. TDMA is the current designation for what was formerly known as D-AMPS. See also IS-136 and D-AMPS. |
| TDN |
Temporary Directory Number |
|
| TD-SCDMA |
Time Division Synchronous Code Division Multiple Access |
A new technology developed by Siemens and the China Academy of Telecommunication
Technology. TD-SCDMA is part of the ITU 3G standard harmonization and will
likely be adopted by some operators in China. This proposed standard is 1.6
MHz wide and uses multiple timeslots, synchronous CDMA, and new detection
and interference cancellation schemes. |
| TDTD |
Time Division Transmit Diversity |
|
| terminal |
|
In wireles communications, used synonymously with such terms as mobile
handset, mobile station, user equipment, or mobile device. |
| TIA |
Telecommunications Industry Association (U.S.) |
|
| time dispersion |
|
Time dispersion is a manifestation of multipath propagation that stretches the signal in time so that the duration of the received signal is greater than the transmitted signal. |
| TOA |
Time of Arrival |
A location technique that uses GSM timing to triangulate the position
of a handset relative to active base stations. Accuracy is good indoors and
in areas of dense base-station coverage, and TOA can be used with legacy
handsets. Specialized equipment is needed at the base station, however, and
planning, deployment, and maintenance costs can be high. |
| transceiver |
|
A transmitter and receiver contained in one package. A 2-way radio or cell phone is an example of a transceiver. |
| transmission plane |
|
In a wireless communications network, the transmission plane consists
of layered protocols that transfer user information and provide control procedures
such as flow control and error correction. |
| transmit diversity |
|
A technique utilizing multiple transmit stations to originate the downlink signal and improve performance. The station used is determined by either a fixed pattern or a quality measurement at the mobile. See also TDTD, STD and TSTD. |
| TSTD |
Time Switched Transmit Diversity |
|
| TTA |
Telecommunications Technology Association (Korea) |
A telecommunications standards setting body in Korea. |
| TTC |
Telecommunications Technology Committee (Japan) |
A private-sector corporate body established in 1985 to prepare domestic standards relevant to Japanese telecommunications. |
| tunneling |
|
Sending data intended for a private network through the public network
using a temporary, secure path. Tunneling enables virtual private networks
to send data across the Internet, for example. Several protocols exist for
tunneling, including the point-to-point protocol (PTPP) developed by Microsoft
and others, and the generic routing encapsulation (GRE) protocol developed
by Cisco Systems. |
