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This project outlines the design of a portable voice-over-IP communicator for wireless networks. It covers the overall goal, functional diagrams, requirements, schedule, and conclusion, aiming to achieve telephone-quality audio with low propagation delay.
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Designing a Communicator ~ Audio Communication on a Wireless Network ~ Mike Pascucci Advisor: Professor Spinelli 10/5/04
Outline • Purpose • Overall Goal • Functional Diagram • Functional Requirements • Schedule • Conclusion • Questions
Purpose Portable Voice-over-IP * Two-way audio communication between …………microcontrollers & wireless ethernet * VoIP exists as free telephone alternative - Advantages: ~ Free ~ Computer-to-Computer and ………………. …..Computer-to-Phone - Disadvantage: ~ Systems using VoIP not portable
Overall Goal 8051 (F020) Cygnal Microcontroller Headphone to DAC Serial-to-WiFi Ethernet By ACKSYS Mic to ADC
Functional Diagrams Analog voice to Digital Digital Data to Serial Port as IP Packets Serial to Wireless To Internet Digital to Analog voice IP Packets from Serial Port to Digital Data Wireless to Serial From Internet …
Functional Diagrams Server Client Serial-to-Wireless sends connection request (to IP designated in code) Connection Accepted Voice into mic, to ADC, to serial, to IP (as packets) Acknowledge Digital Data to DAC, ………………………… tospeaker output Close Connection Connection Closed
Functional Requirements • Telephone Quality Audio ……~ ADC and DAC sample > 8000 bits/sec (8 Kbs) ………with 8 bits/sample • Propagation Delay: 150-200 ms • Ability to connect to another device • Ability to disconnect from that device • Transmit IP Packets with high fidelity
Schedule Stage 0 One 8051 Microcontroller One Headphone / Microphone combo Mic to ADC Headphone to DAC
Schedule Stage 1 Serial-to-Serial Cable
Schedule Stage 2 Dedicated Serial-to-Wireless Devices
Conclusion Basic Tentative Schedule: - Stage 0 by Wednesday, November 3 - Stage 1 by Monday, December 6 - Stage 2 by Monday, January 17 - Overall Goal by Monday, February 14 Proof of Concept for Portable VoIP - Note: Though portable, not necessarily ………..compact – could be made so in the future
Questions References Image of Serial-to-WiFi Ethernet credit: http://www.acksys.fr/us/produits/wl_dongle_oem.htm Image of Headphone/Microphone credit: http://us.st7.yimg.com/store1.yimg.com/I/directron_1812_79736366 Image of 8051F020 target board credit: http://www.silabs.com/products/pdf/C8051F02x-DKrev0_4.pdf Tackling Delay in Today’s Global Voice Networks http://www.tmcnet.com/it/0704/Fpmcsierra.htm