Voice over zigbee networks with environmental monitoring

1. VOICE OVER ZIGBEE NETWORKS WITH
ENVIRONMENTAL MONITORING

2. 1. CONTENTS (1/1)
1. Introduction
2. ZigBee technology overview
3. System Architecture
(A) Hardware Architecture
(B) Software Architecture
4. References

3. 1. INTRODUCTION (1/2)
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.

4. 1. INTRODUCTION (2/2)
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.

5. 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 lowcost wireless communication, such as home
monitoring and automation, environmental
monitoring, industry controls, and low rate
wireless sensor, applications.
It
uses 2.4GHz frequency.

6. 2.ZIBGEE TECHNOLOGY
OVERVIEW (2/3)
Inexpensive
batteries
monitoring application.
Two
in
a
classes of ZigBee devices.
• Full function devices (FFDs)
• Reduced function devices (RFDs)
typical

7. 2.ZIBGEE TECHNOLOGY
OVERVIEW (3/3)
ZigBee

topologies
Router : FFD that can relay message.
 Coordinator: FFD that controls a ZigBee
network.

8. 3. SYSTEM ATCHITECTURE
(1/5)
(A) Hardware Architecture:

Figure shows a typical architecture of the VOZ
device.

9. 3. SYSTEM ATCHITECTURE
(2/5)

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.

10. 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:

11. 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.

12. 3. SYSTEM ATCHITECTURE
(5/5)
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.

13. 4. REFERNECES (1/1)
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 LRWPAN,” 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.
