NRF51822 RSSI for CSMA/CA

Hello,

is it possible to use the RSSI value of the NRF51822 for collision avoidance? How long does an RSSI measurement take?

I'm trying to implement a discovery protocol based on ESB or Gazell:

  1. All nodes are in receive mode (PRX / Host)
  2. Node A starts discovery process (now PTX / Device), sends broadcast with discovery request datagramm on broadcast address
  3. Node B,C,D,.. receives datagramm (PRX / Host)
  4. Node B,C,D,.. switches to transfer mode (PTX / Device) und sends discovery response datagramm <- collisions

My idea at the moment for collision avoidance: Before sending, the transmitter should wait a random time, then checking RSSI, and if free, starts to transmit. This process should be repeated N times, to be sure Node A get the response of all nodes.

Because the nodes are unknown and anonymous, i don't know the addresses (and can't set them for example in gazell to use different rf frequencies).

Thanks!

Best regards, Kevin

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