for its efforts to increase accessibility to communication for people with disabilities. The award holds some irony; it was AT&T that, in the 1960s, resisted efforts to implement TTY technology, claiming it would damage its communication equipment. In 1968, the Federal Communications Commission struck down AT&T's policy and forced it to offer TTY access to its network. Protocols There are many different standards for TDDs and textphones. Original 5-bit Baudot code The original standard used by TTYs is a variant of the Baudot code. The maximum speed of this protocol is 10 characters per second. This is a half-duplex protocol, which means that only one person at a time may transmit characters. If both try to transmit at the same time, the characters will be garbled on the other end. This protocol is commonly used in the United States. This is a variant of the Baudot code, implemented as 5-bits per character transmitted asynchronously using frequency-shift key-modulation at either 45.5 or 50 baud, 1 start bit, 5 data bits, and 1.5 stop bits. Details of the protocol implementation are available in TIA-825-A and also in T-REC V.18 Annex A "5-bit operational mode". Turbo Code The UltraTec company implements another protocol known as Enhanced TTY, which it calls "Turbo Code," in its products. Turbo Code has some advantages over Baudot protocols, such as a higher data rate, full ASCII compliance, and full-duplex capability. However, Turbo Code is proprietary, and UltraTec gives its specifications only to parties who are willing to license it, although some information concerning it is disclosed in . Other legacy protocols Other protocols used for text telephony are European Deaf Telephone (EDT) and dual-tone multi-frequency signaling (DTMF). The ITU V series recommendations are a collection of early modem standards approved by the ITU in 1988. ITU V.21 specifies 300 bits per second duplex mode. ITU V.23 specifies audio frequency-shift keying modulation to encode and transfer data at 600/1200 bits per second. V.18 In 1994, the ITU approved the V.18 standard, which comprises two major parts, a dual standard. It is both an umbrella protocol that allows recognition and interoperability of some of the most commonly used textphone protocols, as well as offering a native V.18 mode, which is an ASCII full- or half-duplex modulation method. Computers can, with appropriate software and modem, emulate a V.18 TTY. Some voice modems, coupled with appropriate software, can now be converted to