I am working to replace an aging radio relay system with something a
little more modern. The limiting factor in the replacement design is that
it must be low power consumption. The wishlist includes:

1) transmit digitally-encoded analog signal,
2) remote assessment of battery condition, solar panel current output,
site dewpoint and temperature,
3) possibly allow for activation of cable heater to deice antenna.

The sites cover 150 mile diameter region with few opportunities for shore
power. I must get the system working off of batteries that are recharged
by solar panels. The existing system already has a power infrastructure,
but I could add additional gel cells to get the antenna heaters working.
If that is impractical, I would like to encode and store data on site
until the antenna is capable of transmitting a signal.

I have been reviewing my options and I have identified two possibilities:
AX.25 and IRLP. I read quite a bit of the dissent about the utility of
AX.25, although I haven't read a reasoned argument regarding its
viability. I cannot have UDP packets floating about; I need error
correction. The data that is being transmitted is too important to allow
for package loss.

Can I get a good argument pro and con for either of these protocols, or
perhaps some help in identifying an alternative technology.

ADVthanksANCE

AX.25 would work well in this application. The key to low power
consumption would be in the selection of the equipment itself. AX.25
does allow for acknowledged transmissions... it's just that most
locational services these days are using UI frames which are generally
unacknowledged. There's no reason you couldn't run this in connected
mode, which would ensure virtually error free delivery. The AX.25
protocol also has built in a digipeting function so each station would
only have to send a signal as far as the next station, rather than the
full 150 mile range of the system. You could also save power by
putting the whole system to "sleep" for significant periods and having
it wake up from time to time to communicate data.

IRLP is really a different beast altogether. It is essentially a
Voice over IP scheme and would not be appropriate for the project you
have in mind.

If I can provide any additional information for you, I can be
contacted at:



John Hansen, W2FS


wrote in message . ..
I am working to replace an aging radio relay system with something a
little more modern. The limiting factor in the replacement design is that
it must be low power consumption. The wishlist includes:

1) transmit digitally-encoded analog signal,
2) remote assessment of battery condition, solar panel current output,
site dewpoint and temperature,
3) possibly allow for activation of cable heater to deice antenna.

The sites cover 150 mile diameter region with few opportunities for shore
power. I must get the system working off of batteries that are recharged
by solar panels. The existing system already has a power infrastructure,
but I could add additional gel cells to get the antenna heaters working.
If that is impractical, I would like to encode and store data on site
until the antenna is capable of transmitting a signal.

I have been reviewing my options and I have identified two possibilities:
AX.25 and IRLP. I read quite a bit of the dissent about the utility of
AX.25, although I haven't read a reasoned argument regarding its
viability. I cannot have UDP packets floating about; I need error
correction. The data that is being transmitted is too important to allow
for package loss.

Can I get a good argument pro and con for either of these protocols, or
perhaps some help in identifying an alternative technology.

ADVthanksANCE

AX.25 would work well in this application. The key to low power
consumption would be in the selection of the equipment itself. AX.25
does allow for acknowledged transmissions... it's just that most
locational services these days are using UI frames which are generally
unacknowledged. There's no reason you couldn't run this in connected
mode, which would ensure virtually error free delivery. The AX.25
protocol also has built in a digipeting function so each station would
only have to send a signal as far as the next station, rather than the
full 150 mile range of the system. You could also save power by
putting the whole system to "sleep" for significant periods and having
it wake up from time to time to communicate data.

IRLP is really a different beast altogether. It is essentially a
Voice over IP scheme and would not be appropriate for the project you
have in mind.

If I can provide any additional information for you, I can be
contacted at:



John Hansen, W2FS


wrote in message . ..
I am working to replace an aging radio relay system with something a
little more modern. The limiting factor in the replacement design is that
it must be low power consumption. The wishlist includes:

1) transmit digitally-encoded analog signal,
2) remote assessment of battery condition, solar panel current output,
site dewpoint and temperature,
3) possibly allow for activation of cable heater to deice antenna.

The sites cover 150 mile diameter region with few opportunities for shore
power. I must get the system working off of batteries that are recharged
by solar panels. The existing system already has a power infrastructure,
but I could add additional gel cells to get the antenna heaters working.
If that is impractical, I would like to encode and store data on site
until the antenna is capable of transmitting a signal.

I have been reviewing my options and I have identified two possibilities:
AX.25 and IRLP. I read quite a bit of the dissent about the utility of
AX.25, although I haven't read a reasoned argument regarding its
viability. I cannot have UDP packets floating about; I need error
correction. The data that is being transmitted is too important to allow
for package loss.

Can I get a good argument pro and con for either of these protocols, or
perhaps some help in identifying an alternative technology.

ADVthanksANCE