Libelium Waspmote, Техническое руководство

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-74- v6.3
802.15.4/ZigBee
8.4. XBee - 900
Module Frequency Tx Power Sensitivity Channels Distance
XBee 900 902-928MHz 50mW -100dBm 12 10km
Figure: XBee 900MHz
Note: The XBee 868 MHz module is provided with 4.5dBi antenna, which enables maximum range.
The frequency used is the 900MHz band, using 12 channels with a bandw idth 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. In the chapter “Certifications”, more
information can be obtained about the Certifications .
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.
{
xbee900.setEncryptionMode(1);
xbee900.setLinkKey(key);
}