BLE network hardening tests , blocking PAwR

[aksh_diode]

Hi,

I am trying to build a BLE PAwR network jammer for wireless network hardening. I have three nrf52840  transmitting on channels 37,38 and 39, which blocks nodes from joining the network as expected. 

Now, I would like to block nodes after the network is established. Do I need a wideband jammer for this, or is it possible to reuse the same setup ?

[Hung Bui]

Hi Aksh, 
PAwR based on top of Periodic Advertising as the bearer for sending data. The Periodic Advertising basically has 2 packets. One is the very short ADV_EXT_IND packet sending over the primary channels (37 38, 39) to tell which channel the main AUX_SYNC_SUBEVENT_IND PAwR packet will be sent. 

A scanner/listener doesn't have to listen to the primary channels to follow the AUX_SYNC_SUBEVENT_IND packets if it's already synced to the Advertiser. So if you only jam 37 38 39 it is not sufficient to block the PAwR communication. You would need either block all channels, or use sync information to know which channel you should block. 

Blocking 37 38 39 can stop new node to sync to the Advertiser.