User manual

toolbar save button becomes available. Clicking on this button will save the current Devices Under Test
settings that will be available the next time you open ComProbe BPA low energy analysis.
To begin sniffing Bluetooth low energy simply click the red Start button on the datasource toolbar.
Specifying the LE Device Address
You may specify the LE device you are testing by typing in or choosing its address (BD_ADDR). You can type it
directly into the drop down, or choose it from the existing previous values list in the drop down.
Alternatively you can open the LE Device Database tab, right-click on any device in the list, and click on Select
LE Device in the pop-up menu. The selected device's BD_Addr and Nickname will appear in the LE Device
field.
To enter the device manually type the address - 12 digit hex number (6 octets). The "0x" is automatically typed in
the drop down control.
Note: If one device changes its address and the other device does not, then select the device
address that does not change for the LE Device Address field.
Once you have the devices address identified, the next step is to identify the Encryption.
LE Encryption
Figure 3.2 - BPA low energy Devices Under Test LE Encryption
1. Enter the Long Term Key for the LE Encryption.
The Long Term Key is similar to the Link key in Classic. It is a persistent key that is stored in both devices and
used to derive a fresh encryption key each time the devices go encrypted.
Click here to learn more about the Long Term Key.
In LE, the long term key is generated solely on the slave device and then, during pairing, is distributed to a master
device that wants to establish an encrypted connection to that slave in the future. Thus the long term key is
transmitted over the air, albeit encrypted with a one-time key derived during the pairing process and discarded
afterwards (the so called short term key).
The long term key is directional, i.e. it is only used to for connections from the master to the slave (referring to the
roles of the devices during the pairing process). If the devices also want to connect the other way round in the
future, the device in the master role (during the pairing process) also needs to send its own long term key to the
device in the slave role during the pairing process (also encrypted with the short term key of course), so that the
device which was in the slave during the pairing process can be a master in the future and connect to the device
which was master during the pairing process (but then would be in a slave role).
Since most simple LE devices are only ever slave and never master at all, the second long term key exchange is
optional during the pairing process.
TELEDYNE LECROY Chapter 3 Configuration Settings
16 Frontline BPA low energy Hardware & Software User Manual