Range delay when a LE_CODED device is say 800m away

[Mahendra Tailor]

Hi
In v5 one can advertise in le_coded and then a central can connect off the resulting AUX packet.

For the AUX_CONNECT packet the inter-packet delay is  T_MAFS which is 300us.

Then in v5.0 spec look at section "4.2.3 Range Delay" on page 2605.

Where it shows that extra delay to add is  (2D*4)ns  and if say D is 800m we have 6.4 microseconds.

Question:
After sending an AUX_ADV packet, assuming that the peripheral then switches on its radio to listen for the AUX_CONNECT after 300us, for how long is it going to listen.
If the central device is 800m away then it should listen for at least more than 6.4 microseconds before giving up that it does not see a preample.

My thought. Depending on that extra listening time, there is going to be a maximum range before a connection is never going to happen because the peripheral will stop listening.

Look forward to hearing from you

Kind regards
Mahendra

[Hung Bui]

Hi Mahendra, 

You are correct on your calculation. We do have added range delay in our protocol stack from S140 6.0.0. The range used in calculation is way more than the 800m of your use case and should cover most use cases. We currently don't have an option to adjust this number. 

[Mahendra Tailor]

Hi Hung
That is really good news. 
I am curious about how optimistic you are in how far the two nordic devices can be :-)
You say 'way more than 800m'.
It would be good to know how much more.

[Hung Bui]

Unfortunately, it's not possible to provide more information regarding that. 

But one of our colleague made a test at 0dbm and he got 1.3km range. It's described here.