Information processing techniques program, volume 2: Wideband integrated voice/data technology

The goal of this program is the investigation and development of techniques for integrated voice and data communication in packetized networks which include wideband common-user satellite links. Specific areas of concern are the concentration of statistically fluctuating volumes of voice traffic; the adaptation of communication strategies to conditions of jamming, fading, and traffic volume; and the eventual interconnecting of wideband satellite networks to terrestrial systems. The current report covers work in two areas: a study of speech concentration requirements and a simulation of a technique for adaptive variable-rate packet speech networking. The speech concentration requirements study begins with an identification of the basic elements of a speech concentration facility and an outline of design objectives relating to the separation of functions among these elements. Access area options, voice terminal design issues, and concentrator requirements are then each discussed in more detail. The adaptive-networking efforts are based on an embedded speech coding technique coupled with priority-oriented packet handling and end-to-end flow control. The effects of these strategies are being studied in the context of a simple network topology consisting of a central node through which pass 16 paths connecting 4 nodes on either side.