-35-
v5.8
Radios
Figure : XBee TX Power
All information about their programming and operation can be found in the 868MHz Networking Guide available at
of Libelium website.
7.5. 900MHz
Module
Frequency
Tx Power
Sensitivity
Channels
Distance
XBee 900
902-928MHz
50mW
-100dBm
12
10km
The frequency used is the 900MHz band, using 12 channels with a bandwidth of 2.16MHz per channel and a transmission rate
of 156.25kbps. The use of this module is only allowed in the United States and Canada. More information can be obtained about
the Certifications in the corresponding section.
Figure : Channel frequencies in the 900MHz band
Encryption is provided through the AES 128b algorithm. Specifically through the type AES-CTR. In this case the Frame Counter
field has a unique ID and encrypts all the information contained in the Payload field which is the place in the link layer frame
where the data to be sent is stored.
The way in which the libraries have been developed for module programming means that encryption activation is as simple as
running the initialization function and giving it a key to use in the encryption.
The classic topology for this type of network is a star topology, as the nodes can establish point to point connections with
brother nodes through the use of parameters such as MAC address or that of the network.
All information about their programming and operation can be found in the 900MHz Networking Guide available at
of Libelium website.
