UWE Bristol Engineering showcase 2015

Benjamin Fatunmise
Meng Electronic engineering
WSNs using the ZigBee, with emphasis on communication
This project embarks on the study of wireless technology, in particular the investigation of the implementation of a wireless monitoring
and control system, with a special emphasis on communication. The monitoring and control of an Incubator was targeted as a case
study. The wireless protocol that was considered was the ZigBee. The radio which was used to support the ZigBee was the XBee. “The
XBee is a brand of radio that supports a variety of communication protocols, Including ZigBee, 802.15.4,Wi-fi,among others”
Project Supervisor
Mokhtar Nibouche
Project Conclusion
Three tests were performed:
• The first was a WSN network with
digital/analogue temperature and humidity sensor
where an open loop and closed loop system were
studied in depth.
• The second was a test of the received
signal strength (RSSI) at various distances bearing in
mind the factors such as; line of sight (LOS) and
Non-line-of sight (NLOS).
• The last was a measure of the packet
delay(round trip time) in a point to point network
RSSI(dBm)
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-55
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0 10 20 30 40 50 60 70 Distance(meters)
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-55
RSSI LOS
RSSI NLOS
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All three of the tests proved successful when using
the analogue and digital components. From each test,
valid conclusions were made, these were;
• With the increase in distance the
communication will falter. It will falter much more if
there are obstructions in the way of the XBee
modules line of sight.
• Most of the delay in the round trip
time is caused by the acknowledgement that needs
to be sent from the coordinator when it receives the
packet from the router.
• A closed loop system implemented
within a WSN can help recognize and resolve issues in
which in this case can be a high
temperature/humidity.
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Project Objectives
Signal strength vs distance
1. Successful wireless Connection (a working wireless sensor
network)
2. Parsing and data acquisition
3. Analyse wireless Signal (data transmission rates and packets)
4. Closing the wireless loop
Final thoughts!!!
it would have been interesting to see the “Internet of things” implemented in some
type of manner. One aspect that would aid curiosity is “what if the Wireless
incubator system could be controlled from a smartphone?” There are many devices
currently which send information to a cloud(online) for people who are miles away
to view. This is the extent of wireless technology currently. An instance where this
would prove beneficial is if you had to leave the incubator running for a long period
of time, the individual would need to monitor the incubator some way. If the
individual could monitor whilst being on the move, that would prove to be the
most ideal situation. Methods to achieve this would be extremely informative,
pleasing and exceedingly helpful to the everyday individual.
Project summary
The project as whole revolved around the
communication of wireless sensor networks. The aim
of project was to put the wireless connections to the
test under various conditions testing its limits and it
strengths. Between the three most prominent
wireless protocols (WI-FI, Bluetooth and ZigBee),
ZigBee was the protocol favored for this project
simply due to its low power consumption, simple
network deployment, low installation costs and
reliable data transmissions. For a communications
project involving a WSN this would be the most ideal
solution