AT&T Wireless introduces IS-136 next generation of TDMA digital service -- Perot Systems to use in-building wireless system.

DALLAS--(BUSINESS WIRE)--Dec. 4, 1995--AT&T Wireless Services Inc. has launched the next generation of digital service based on the advanced TDMA (Time Division Multiple Access) standard.

The new service will greatly extend normal wireless telephone battery life, enable users to receive short text messages over their cellular telephone, and provide for separate rate plans for home, office, and mobile wireless usage.

The new technology, based on Interim Standard (IS) - 136, is now installed at Perot Systems in Dallas, and is expected to be become available to most AT&T Wireless markets and customers in 1996. The IS-136 standard utilizes a digital datapath, called a "digital control channel," between the wireless network and the user, to bring wireless communications features and services to customers.

"The IS-136 technology will allow our customers to truly rely on their portable devices and control their communications," said Nicolas Kauser, chief technology officer, AT&T Wireless Services Inc. "We have been pioneers in this new technology and today there are more than 1.5 million digital customers worldwide who are enjoying lower prices and continually improving service due to TDMA digital. We have a proven winner!"

The Perot "network" includes two microcells with a custom designed, in-building radio antenna distribution system. The network is connected to the Perot PBX allowing a call to an employee's desk phone to also ring their cellular telephone and vice versa. Perot employees can also receive text messages over their cellular phones. With microcells manufactured by Ericsson and cellular phones by Nokia, there is robust coverage throughout Perot's facility.

"We are excited to be using the most advanced wireless communications system available today," said Phil Evans, senior telecommunications consultant, Perot Business Systems. "Through this technology partnership we can satisfy our clients business needs as well as our own internal requirements. This is a case of intelligent application of technology giving us a competitive advantage."

AT&T Wireless has implemented TDMA digital systems throughout its 800 MgH license areas that include nearly 100 million potential customers, or roughly 40 percent of the U.S. The company will upgrade these markets to the advanced, IS-136 systems by early next year.

In addition, AT&T Wireless will use the TDMA IS-136 standard for development of its recently licensed wireless systems in the 1900 MgH frequency covering an additional 112 million potential customers. These systems are expected to be on-line beginning in early 1997. In all, the company will offer the nation's largest wireless coverage area that will include nearly 80 percent of the county and 41 of the top 49 U.S. cities.

With the digital control channel users will enjoy many new features including:

Extended battery life: The digital control channel allows the telephone to operate in a "sleep mode." Being digitally synchronized with the wireless network, phones "go to sleep" for all but six mili-seconds of each second cycle and when the phone "awakens" it receives any incoming call. The initial net result is at least double existing standby battery life.

Cellular messaging: This feature allows a telephone to receive and display short, alpha-numeric messages sent by a PC, or by telephone DTMF tones, to leave a call back number. In addition, if a call back number is left on the Nokia phone, the wireless user simply presses one "softkey" and the number is dialed.

With cellular messaging, telephones can also receive messages without ringing the phone, allowing customers to leave phones on during meetings, without interrupting meeting participants.

Differentiated access: IS-136 is also designed to allow differentiated service offerings to key customer segments. This phone alerts the wireless network of the customer's location and displays the "location identification" on the customer's telephone. The customer is then billed at different rates depending on their location.

For example, the word "office" may appear on the display indicating the customer will be billed at a flat monthly rate for all calls made or received at the office. Outside the company premise, the phone display will operate like a traditional cellular phone indicating the customer will be billed at their designated cellular rate.

AT&T Wireless Services Inc. is the nation's largest provider of cellular service offering wireless voice and data communications. The company has nearly 5 million cellular customers and licenses to eventually cover 80 percent of the United States.

Additionally, AT&T Wireless Services Inc. is the nation's fifth largest messaging service provider and a world leader in air-to-ground communications services.

CONTACT: AT&T Wireless Services Inc.

Bob Ratliffe, 206/828-8685 or 206/979-4254 portable

Todd Wolfenbarger, 206/828-1851 or 206/979-2677 portable