Prizm and airdelay parameter

Ok, am doing some playing and find that Prizm seems to report all 900 MHZ units distance
incorrectly (or at least according to the AP and SM themselves).

It would appear that 2.4GHZ units use 49 feet per airdelay unit as their measure
(which works and both Prizm and the ap/sm report the distance the same)
(EG: airdelay * 49 / 5280 = distance in miles.)
It would appear that 900MHZ units use 147 feet per airdelay units as their measure
(which works on the AP/SM and gives the same distance measure that they report)
(EG: airdelay *147 / 5280 = distance in miles.)
but is NOT the value/number that Prizm reports.

so, who is correct, all my 900 MHZ AP and SM that say 54 airdelay units is 1.5 miles
or Prizm???

Larry Smith

I see the same issue. I trust the AP/SM and do not look at Prizm as the distances show incorrect.

This was discussed on Mototola’s WISPA list.

Prizm is not doing the math correctly for 900MHz units, so simply disregard the data in Prizm with these modules. It is listed under their “open issues” in the release notes I believe.