voice over zigbee networks with environmental monitoring

PRESENTED BY:WAQAR AHMED

(BETL/H/F10/0111)

Waqar.Ahmed_s@yahoo.Com

VOICE OVER ZIGBEE NETWORKS WITH ENVIRONMENTAL MONITORING

1. Introduction

2. ZigBee technology overview

3. System Architecture

(A) Hardware Architecture

(B) Software Architecture

4. References

1. CONTENTS (1/1)

To present a voice transmission system, one of telecommunication value-added services, based on the low-rate ZigBee networks.

To present a model to perform a sensor role as a member of ZigBee networks in addition to providing the cost effective voice transmission function.

1. INTRODUCTION (1/2)

The initial objective of the ZigBee alliance provides a wireless platform for remote monitoring and control applications including simplicity, low-cost, and low-power.

ZigBee is designed to transmit low-rate data with low-energy consumption within a short-distance.

1. INTRODUCTION (2/2)

2.ZIBGEE TECHNOLOGY OVERVIEW (1/3)

ZigBee is the IEEE standard 802.15.4.

The ZigBee technology is designed to provide a simple, battery-powered, and low-cost wireless communication, such as home monitoring and automation, environmental monitoring, industry controls, and low rate wireless sensor, applications.

It uses 2.4GHz frequency.

2.ZIBGEE TECHNOLOGY OVERVIEW (2/3)

Inexpensive batteries in a typical monitoring application.

Two classes of ZigBee devices.• Full function devices (FFDs) • Reduced function devices (RFDs)

2.ZIBGEE TECHNOLOGY OVERVIEW (3/3)

ZigBee topologies

Router : FFD that can relay message. Coordinator: FFD that controls a ZigBee network.

(A) Hardware Architecture: Figure shows a typical architecture of the VOZ

device.

3. SYSTEM ATCHITECTURE (1/5)

It is controlled by a 16 bit microcontroller running at 16 MHz .

A temperature sensor, a humidity sensor, and an illumination sensor are connected to monitor environmental information.

It is equipped with a microphone, an audio input and output port for voice recording and playing.

3. SYSTEM ATCHITECTURE (2/5)

3. SYSTEM ATCHITECTURE (3/5)

To perform voice recording and playing, it utilizes the internal ADC(Analog to Digital Converter), PWM(Pulse Width Modulation), internal timers, and DMA (Direct Memory Access) is used to transmit voice data for reasonable transmission.

(B) Software Architecture:

3. SYSTEM ATCHITECTURE (4/5)

IEEE 802.15.4 PHY/MAC protocol is basically used for wireless communication in ZigBee networks.

Two applications to monitor environmental data and transmit voice data are designed and implemented based on ZigBee networks.

Both the voice data and the environmental data are transmitted by the ZigBee specification.

The voice application is especially implemented with the internal components to reduce cost.

Using the ADC, voice is converted into digitized raw data with voice conversion resolution.Then raw voice data can be converted into real analog voice form PWM signal.The internal timer is used to record periodically and generate PWM output.DMA is used to transfer Voice data.

3. SYSTEM ATCHITECTURE (5/5)

ZigBee Specifications, ZigBee Alliance, Oct 2007,

ZigBee Alliance, https://www.zigbee.org

Eunchang Choi et al, “Simulation and Implementation of Voice Over IEEE 802.15.4 LR-WPAN,” In Proc. Of the 26th International Conf. on Consumer Electronics (ICCE), USA, Jan.2008.

Chonggang, Wang et al, “Voice Communication Over ZigBee Networks” Communication Magazine, IEEE, 46(1):121-127,January 2008.

4. REFERNECES (1/1)