[aprssig] RE: indoor tracking.

Robert Bruninga bruninga at usna.edu
Wed Jun 1 16:22:23 EDT 2005


>Why ask the ARRL to reinvent the wheel? 
>You can get two or three free RFID fobs now 
>from Exxon-Mobil...

Because:
1)  The HAM comunity is 600,000 strong
in the USA.  And Ham-RFID to be of any value  in
this ham radio applicaiton, needs to be all-inclusive.

2) And RFID is a mass-produced item in very
large quantities.  We need to work this problem
from the top down because it either works for
all of us (that want to use it) or it is just a toy,
of no practical value for what I think it could be
used for.

3) We need the HUGE code space so that we
can MAP our callsigns to the built-in codes.
with a single reproducible algorithm.  THe way
I see it, for ARRL calls, the code space has to
be A,N,K,W for the first letter (4)
then  4 characters of 26 possibilities then one
character of 10 possible numerals and one digit of
3 possiblities to tell where to put the numeric.

This would require a 54 million code space, or
about 8 digit numbers.  But doing it this way
we dont need to manage a 600,000 list of
callsigns and mapped numbers.  We compute the
call directly from the number.

de Wb4APR, Bob









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