Handheld Analyzer of IEEE 802.15.4 PHY and MAC Frames
Milan Simek, Jiri Pokorny, Miroslav Botta, and Lubomir MrazBrno University of Technology, Czech republic,
16.11.2012
Motivation
The WISLAB team is working at research project „Adaptive WSN with Data Visualization for Crises Management“, where many Zigbee-based sensors will be deployed.
During the testbed deployment, the motivation has arised ...
To fast and on-site analyze activity and signal quality of individual Zigbee nodes .
Motivation cont’d
Well-known ad-hoc wireless automation protocols is based on the original or slightly modified IEEE 802.15.4 MAC.
IEEE 802.15.4 PHY
IEEE 802.15.4 MAC
We need to: analyse channels energy identify nodes monitor RSSI (dBm) monitor LQI check nodes activity
All parameters defined by 802.15.4 PHY and MAC
Radio analyser working at lower levels finds wider application between various wireless ad-hoc protocols
1 channel: 868MHz10 channels: 916 MHz16 channels: 2,4GHz
addressing & access
Well-known WSN analysers
Daintree Sensor Network Analyser
IEEE 802.15.4, Zigbee, 6lowPAN very complex and powerful packet decoding topology and association visualization PC-based only 2,4 GHz band no more supported (discontinued on 2010)
Perytons Analysers
2,4GHz, 868MHz/916MHz single & multichannel observation IEEE 802.15.4/4a, Zigbee, 6lowPAN, PLC, Dash7, allow to own protocols … quite powerful substitution of Daintree SNAPC-based (works on Tablet)
Packet analysers: in addition to radio analysis provide decoding of the packets according to supported protocol
Well-known WSN analysers
WiSpy & Chanalyser
observes dBm across the WiFi and 15.4.channels 2,4 GHz, 868MHz/916MHz offers logging and reports suitable for interference monitoring PC-based
Telegesis Zigbee Range Finder
handheld version measure bidirectional signal energy in dBm one monitor station & two “satellites” monitor only channels No.11, 14, 15, 19, 20, 24, 25
Channel analysers: measure signal energy through the channels
Our handheld 15.4. analyzer
Features
works in2,4 GHz reports energy scan in graphical or text list mode configurable sniffing time (how long sniffs the channel) configurable resolution of graphs for each node reports
address [16bit hex]RSSI [dBm]LQI[-]
results are sorted according to address or RSSI identifies 15.4. signals announces node inactivity
Does not aim to be better, it is just developed for our specific needs.
HW & SW
Memisc Wireless - IRIS node
2,4 GHz radio AT86RF230 8bit ATmega1281 USART, SPI, 51pin port extension
Atmel – IEEE 802.15.4 MAC employs CSMA-CA defines addressing mechanism performs energy detection RSSI and LQI measurement data transmission and reception …
Solution based on
Analyzer control
After start up, user selects either to scan all sixteen (11-26) IEEE 802.15.4 channels or one can choose the sniffed channel manually:
Analyzer control
In the Channel scan menu, first define how long the analyser are to scan at each channel.
The results can be displayed in the Graphical (bars) form or in the Text list form:
If you don’t know, where your wireless network communicate
Analyzer control The dBm values at the analysed channels in the Text list form are displayed below. The symbol "15.4" indicates that that channel is occupied by the technology complying with the IEEE 802.15.4 standard. Graphical Text list
Analyzer control
By pressing BACK button, the user can jump to the main menu and manually selects the desired channel for the analyses.
Once the channel is selected, it is possible to sort the results according to the MAC address or RSSI value:
Analyzer control
The freshness of the dBm values are indicated by the "x" symbol. When the symbol appears, the reported dBm value was obtained more than 10 seconds before:
Conclusion
Introduction of well-known WSN analyzers
HW & SW used
The analyzer offers: energy scan through the channels and identification of node behavior.
Future work:
To substitute the IRIS node by individual components to push down a priceTo assembly 2,4 GHz and 896MHz/916MHz radios separatelyTo use the graphical display with higher resolutionTo export logged data through the USART or SD card