T

---

Tablet Computer/PC

A design for a fully-equipped personal computer that allows a user to take notes using natural handwriting on a stylus- or digital pen-sensitive touch screen instead of requiring the use of a keyboard. A tablet computer/PC is similar in size and thickness to a yellow paper notepad.

TCP

See Transmission Control Protocol (TCP).

TCPng

Short for TCP next-generation, which is another term used to describe Stream Control Transmission Protocol (SCTP).

See also Stream Control Transmission Protocol (SCTP).

See also TCP.

TCP/IP Suite

This refers to a collection of communication protocols allowing communication between groups of dissimilar computer systems from a variety of vendors. The TCP/IP suite provides the basic framework for communication over the Internet. The TCP/IP suite consists of a number of different protocols, e.g. Address Resolution Protocol (ARP), File Transfer Protocol (FTP), User Data Protocol (UDP), Simple Management Transfer Protocol (SMTP), Telnet, Domain Name System (DNS), and more.

TDMA

See Time Division Multiple Access.

Telephony

The science of translating sound into electrical signals, providing a process for transmitting the signals and then converting them back to sound. Although the term could apply to POTS, it is more commonly used to refer to computer hardware and software that performs functions traditionally performed by telephone equipment. For example, telephony hardware and/or software can to turn a PC into a telephone and/or sophisticated answering service. The most popular telephony application to date is voice mail.

Temporal Key Integrity Protocol (TKIP)

A protocol that is a part of the IEEE 802.11i encryption standard for wireless LANs. TKIP is oft-times referred to as the next generation of WEP (Wired Equivalency Protocol), which is currently used to secure 802.11 wireless LANs. TKIP provides per-packet key mixing, a message integrity check and a re-keying mechanism.

See also WEP.

Temporary Local Directory Number (TLDN)

A number that is used by cellular networks to deliver wireless calls to roaming wireless customers.

Terminal Node Controller (TNC)

As used in this book, TNC refers to a device which assembles and disassembles frames and usually includes some form of a user interface and command set. The TNC is used in conjunction with a radio, modem, and terminal for packet radio applications. The TNC may be implemented in hardware or software.

Time Division Multiple Access

This is a method of digital wireless communications transmission that allows a large number of users to access a single radio frequency channel without interference. With TDMA, each user is given a unique time slot within each channel.

TKIP

Pronounced "tee-kip," this acronym of Temporal Key Integrity Protocol is commonly used in place of its progenitor.

See also Temporal Key Integrity Protocol (TKIP).

Token Ring

A type of computer network in which all the computers are arranged (schematically) in a circle and a token (a special bit pattern) travels around the circle. To send a message, a computer catches the token, attaches a message to it, and then lets the packet continue its travel around the network.

Total Cost of Ownership (TCO)

A type of calculation designed to help consumers and enterprise managers to assess direct (and indirect) costs and benefits related to the purchase of an IT component. The intention of the TCO is to arrive at a final figure that will reflect the effective cost of purchase, all things considered.

Touchscreen

A display device with a clear glass panel (typically liquid crystal) overlay that acts as an input device by responding to the touch of the user.

Transmit Power (Tx Power)

The amount of RF power that comes out of the antenna port of the radio. Transmit power is usually measured in Watts, milliwatts, or dBm.

See also Receive Sensitivity (Rx Sensitivity).

Transmission Control Protocol (TCP)

The Transport Layer protocol used in IP networks, which includes the Internet, local area networks, wireless local area networks, intranets, and extranets. TCP breaks data streams such as messages or file transfers into small "packets" and hands them to IP for transmission across the network. On the receiving end, TCP collects the packets and puts them in the correct order, restoring the original data stream.

Transmission Power Control (TPC)

A technique used to limit the transmitted power to the minimum needed to reach the furthest end-user.

Tuple

A term that refers to an ordered sequence of fixed length of values of arbitrary types. For example, the two end points of a session or application use the IP address and the TCP port number at each end point as a tuple to form a connection

Tx

Transmit/transmitter.

Tx Power

See Transmit Power (Tx Power).

---