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Conference Paper

Title

A Distributed, Mobile Wireless Infrastructure for Multimedia Applications

Abstract

This paper, we will present network concepts and preliminary results relative to the design of a wireless, mobile infrastructure for multimedia communications. This research is supported by ARPA under the WAMIS (Wireless Adaptive Mobile Information Systems) program. The network design requirements are: - mobility handling ("instant" infrastructure) - multihop communications - multimedia support (data, voice, video) - robustness to failures and environment changes Unlike cellular systems, WAMIS is not constrainted by a fixed wired network. Instead, it enables rapid deployment and dynamic reconfiguration of a network of wireless stations. The target applications of this wireless, instant infrastructure are civilian (emergency communications in disaster areas, e.g. fire, earthquake, etc.), law enforcement (e.g. search and rescue) and military (e.g. rapid deployment of tactical units). The following assumption are made regarding the direct-sequence, spread spectrum radios: 915 MHz frequency, 12.7 Mchips/sec; spreading factor 15 to 127 chips/bit; data rates ranging from 100 to 800 kbps; transmission range up to 1 km; dynamic power control (16 dB range); dynamic code selection. Data transmissions are handled by the network in a datagram fashion, with end to end reliability provided by TCP. Voice and video transmissions are handled with a virtual circuit approach, with quality of service and bandwidth guarantee. We assume adaptive video coding (from 600 kbps at 15 frames/sec down to 60 kbps at 5 frames/sec), as well as adaptive speech coding (from 32 to 4 kbps, with echo cancellation). Two main challenges in this project are: (a) the presence of both mobility and multimedia requirements, and; (b) the support of multiple real time (voice/video) connections via CDMA, using dynam...

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Information & Date

Fifth WINLAB Workshop on Third Generation Wireless Networks, NJ, April. 1995

Authors

Mario Gerla
Jack Tzu-chieh
Nicholas Bambos
Shou C. Chen