During the research of the Waspmote sensor platform, several tests were made using different kinds of transceivers according to the frequency bands (2.4GHz, 868MHz and 900MHz) and the transmission power (1mw, 100mW, 315mW).
The tests performed in the Monegros Desert (Spain) had the purpose of seing the capabilities and limits of the 802.15.4/ZigBee radios integrated in Waspmote.
Among the 6 different links (356m, 639m, 1239m, 3810m, 6363m,12136m) were chosen Line of Sight (LOS) and Non Line of Sight (NLOS) configurations which were tested always using omnidirectional antennas (2dBi, 5dBi).
Highlights:
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- 12km link using the 868 and 900MHz radios in LOS configuration.
- 7km link using the 2.4GHz – 100mW radio and in LOS configuration.
- 6’5km link using the 868 radio in NLOS configuration
Notes:
- The maximum theoretical distance for the 868MHz radio in Waspmote is 40km. The reason we could not test a 12km longer link was due to topology restrictions.
- All the tests were made using just the parts included in the Waspmote Dev Kit (including the 5dBi antennas).
The final study and analysis of the data obtained was made as a collaboration between the Royal Institute of Technology – KTH, Stockholm (Sweden), the University of Cape Town, Cape Town (South Africa) and Libelium.
The results obtained were presented in the European Wireless Sensor Network Conference (EWSN2010) in Coimbra, Portugal. The article: “Experimental Evaluation of Radio Transceivers for Sensor Networks in Harsh Environments”.