MURRAY HILL, N. J. — People with speech or hearing disabilities will be able to make digital cellular phone calls - including 911 emergency calls - - using text-telephone (TTY) devices plugged into wireless telephone handsets, thanks to the Bell Atlantic Mobile unit of Bell Atlantic Corporation (NYSE:BEL) and Bell Labs, the research and development arm of Lucent Technologies (NYSE:LU).
Using innovative software from Bell Labs, Bell Atlantic Mobile plans to be first in the world to make digital wireless systems compatible with TTY devices, using the same path used for voice transmission. The carrier plans to introduce the new service in the second half of next year with the service initially available through Bell Atlantic Mobile's direct sales channels.
The innovation pioneered by Bell Labs researchers was prompted by Bell Atlantic Mobile's priority in meeting the needs of speech and hearing- impaired customers, especially in emergency situations. Lucent is informing the Federal Communications Commission (FCC) and industry organizations that it is making the patents and technology available royalty-free to wireless service providers and manufacturers serving TTY customers, subject to certain conditions.
"We're going to bring the benefits of digital wireless service to a large segment of the population that up until now couldn't use this state- of-the-art technology" said Ted Hoffman, vice president of Technology Development for Bell Atlantic Mobile. "In addition, this successful collaboration benefits other wireless carriers' customers."
The FCC has mandated that wireless service carriers provide TTY users access to 911 emergency services. Carriers deploying digital wireless systems have so far been unable to meet the FCC requirement, however, because existing digital wireless systems cannot accurately pass the specially encoded audio tones produced by TTY devices.
Lucent's solution, developed by Steven Benno and Michael Recchione, of the Bell Labs Speech and Audio Processing Technologies group, offers TTY users essentially error- free digital transmission, even in areas with extremely poor reception. The technology involves upgrading software both in the network and in the digital handset, yet retains compatibility with existing digital wireless network standards.
The Telecommunications Industry Association (TIA) has adopted the Bell Labs solution as a TTY solution that is compatible with the ANSI-41 standard for code-division and time-division multiple-access (CDMA and TDMA) wireless systems.
"I can't think of a better example of cutting-edge communications research being used to help people," said Ed Hall, co-chair of the Cellular Telecommunications Industry Association's (CTIA) TTY Industry Forum. "We're extremely pleased that Lucent devoted its energies to such an important innovation for hearing- and speech-impaired people."
Digital wireless transmissions inherently contain errors, but error correction techniques can mitigate the problem by reconstructing speech to keep it intelligible on the receiving end. However, digital networks are less forgiving in the case of the tones generated by TTY devices, and the transmission errors can cause characters to be missed or changed on the receiving end, resulting in unintelligible messages.
Lucent's solution to this problem is to detect the TTY characters being sent and to repeatedly transmit those characters to the receiving end. The repetition allows the receiving end to correctly regenerate the tones corresponding to those characters despite over-the-air errors.
Unlike other techniques, Lucent's solution treats TTY calls as data transmissions that also permit voice conversation over the same connection. Typically, people with speech impediments and hearing- impaired people who can speak require TTY capability in one direction and speech transmission in the other direction. While data-only calls have a built-in capability for error correction, they do not allow a TTY user to switch between voice and TTY. Lucent's method treats TTY calls the same as voice calls -- a feature called voice carryover/hearing carryover - that cannot currently be supported by treating TTY as a data call.
Bell Atlantic Mobile owns and operates the largest wireless network in the East and systems in the Southwest, covering 216,000 square miles, and the largest chain of retail outlets devoted exclusively to wireless voice, data and paging. Based in Bedminster, NJ, Bell Atlantic Mobile has 7.3 million customers and 8,800 employees from Maine to Georgia and, through a separate subsidiary in the Southwest. Through its "Wireless at Work..." community service program, the company uses its technology to help individuals and communities improve security and emergency communications. Bell Atlantic Mobile's parent, Bell Atlantic Corporation (NYSE:BEL) is one of the world's largest wireless communications companies, with domestic operations in 25 states and international investments in Mexico, Europe and the Pacific Rim. For more information on Bell Atlantic Mobile visit: http://www.bam.com ; on global operations visit: http://www.bellatlantic.com/worldwide .
Lucent Technologies, headquartered in Murray Hill, N. J., designs, builds, and delivers a wide range of public and private networks, communications systems and software, data networking systems, business telephone systems, and microelectronics components. Bell Labs is the research and development arm for the company. For more information on Lucent Technologies, visit its Web site at http://www.lucent.com .