CC1125: Listen Before Talk (LBT)

Hi,

Yes, it meets ETSI LBT spec.

Yes, you can control time out from host MCU.

Thanks,

PM

PM said:

it meets ETSI LBT spec

indeed - the ETSI spec is equally opaque on this.

PM said:

you can control time out from host MCU

I know I can - the question was whether I must - ie, whether  that's the only way!

EDIT

The algorithm seems to be:

  START 
    |
    | Start timer, Tf = 5ms
    |
    +<------------+
    |             |
    V             |
  LISTEN          |
   til            |
  timer           |
 expires          |
    |             | Start timer,
    |             | 0 < Tps < 5ms
    V             |
 channel          |
  free?  --NO-->--+
    |
   YES
    |
    |
    v
 TRANSMIT

Which clearly has a potential endless loop.

There more complex ways of doing this, such as doing CSMA.

For ETSI, usually the only way would be to do LBT the way you are showing in the diagram.

But the question was how to escape from the potential endless loop in that implementation.

Specifically, whether the CC1125 provides an exit mechanism - or if that has to be managed by the external host microcontroller.

Andy Neil said:

whether the CC1125 provides an exit mechanism

Seems the answer is, NO.

Andy Neil said:

or if that has to be managed by the external host microcontroller

Which leaves that as the only option.