868Mhz - Libelium waspmote plug & sense Technical Manual

7.4. 868MHz

Module Frequency
XBee 868 869,4 – 869,65MHz
The frequency used is the 869MHz band (Europe), using 1 single channel. The use of this module is only allowed in Europe. See
certification section to obtain more information.
Figure : Channel frequency on 869MHz
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 information contained in Payload field which is the place in the link layer frame where the
data to be sent is stored.
The way in which 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.
Common topology in 868 Networks is Star topology, where nodes send directly the sensor data to the Gateway.
Figure : Star topology
Regarding the energy section, the transmission power can be adjusted to several values:
Figure : Transmission power values
Transmission Power
315mW
Parameter Tx XBee - 868
0 0dBm
1 13.7dBm
2 20dBm
3 22dBm
4 25dBm
-34-
Sensitivity Channels
-112dBm 1
Radios
Distance
12km
v5.8