[drats_users] Possible Who Is Online feature request

[Nate Duehr]

On Tue, 21 Apr 2009 07:18:02 -0700, "Dan Smith" <dsmith at danplanet.com>
said:

> Yep, as you indicated, pinging CQCQCQ will cause everyone to respond.
> Each station will (in the case of a CQ ping) wait a random number of
> seconds between 0 and 10 before replying to avoid stepping on each
> other on RF.

Thinking about Pings the other night, when I saw two stations pick the
same "random" number and collide...

Think it would be useful to have Ping replies be "ACK'ed"?

State machine/flow would be something like this: 

- Station A sends CQCQCQ ping.
- Stations B & C do as they do today, pick a random number of seconds
from 0-10 and reply.
- Station A "ACK"'s each reply as it comes in.
- Stations B & C track whether their ping reply was ACK'ed.  If it
wasn't, they pick another random number of seconds and try again up to a
specific (LOW!) number of retries.

This way, if ping replies are hammered by voice traffic, another station
picking the same "random" reply interval, etc... the station requesting
the original Ping to CQCQCQ always is assured of getting a reply from
each station on-frequency.

The reason for the "give up" timer is myriad... bad paths on
simplex/repeater, etc... that cause the whole mechanism to fall apart,
if there were no "give up" number of retries, Stations B & C would
continue trying to reply to the original Ping request "forever". 

Same algorithm for individual station pings, of course... but less
"important" for those in some ways.

What'cha think Dan?  Everyone?

Nate WY0X
--
  Nate Duehr
  nate at natetech.com