Hi guys

I am reading this application note/report from Microchip:
http://ww1.microchip.com/downloads/en/AppNotes/00001629A.pdf

On page 15, all the modules have bigger range without acknowledge, but have a small range with acknowledge. Why is that?? I can't think of a reason myself what with ACK would effect the range.

Thanks guys!

 

Hi guys

I am reading this application note/report from Microchip:
http://ww1.microchip.com/downloads/en/AppNotes/00001629A.pdf

On page 15, all the modules have bigger range without acknowledge, but have a small range with acknowledge. Why is that?? I can't think of a reason myself what with ACK would effect the range.

Thanks guys!

IIRC "Broadcast" packets are (spectrally) 'narrower' and, hence, of greater effective (i.e. 'time-distributed') ERP (Do note the adjective 'effective'! ) -- That said, the range disparity, while measurable, should be so slight as to be negligible in most applications...

Best regards
HP

 

When you said 'narrower', did you mean the package is very small?

 

When you said 'narrower', did you mean the package is very small?

No, Spectrally narrower (i.e. narrower RF bandwidth)

Best regards
HP

 

Interesting, I would think they use the same bandwidth in all transmission (when not doing frequency hopping).

 

Interesting, I would think they use the same bandwidth in all transmission (when not doing frequency hopping).

I believe the 'unicast' protocol entails FHSS operation (re: acknowledgement 'bursts'). While, in theory, owing to error correction and general (NB) interference 'immunity', such might be expected to increase range, the FHSS 'bursts' are commonly 'attenuated' (actually, transmitted at reduced power) in the interests of economy and RFEF exposure compliance - with the result that the range 'breaks even' or, indeed, falls short of correspondent NB range...

Please note: The, IMO, dubious, use of the terms 'broadcast' and 'unicast' in this context is entirely down to Microchip! --- 'Tho I am obliged to adopt the manufacturer's jargon am I to communicate - Pun not entirely not intended

Best regards
HP

PS: Please be advised that my responses on this thread are based 90% upon memory and 10% on 'guesswork' -- hence it's far from 'gospel'