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Re: MIR transmits UNUSEFUL data !


On 19 Jun 98, at 15:58, Bob Bruninga wrote:

> On Fri, 19 Jun 1998, Alain De Carolis wrote about the MIR BBS:
> > Well i have counted 140 BUSY flags on 160 packets received! ... Meaning
> > that 87% of the data trasmitted by MIR in a entire pass is... UNUSEFUL.
> > ...  We must think about the new ISS. I believe that a too popular
> > amateur radio system is not a right choice. A less accessible one ...
> > would allow all the really interested hams to work the station easily,
> > and would cut off all the "just courious" ....
> Another alternative is to make better use of the downlink so that everyone
> receives lots of data without everyone having to have an uplink.

Why re-inventing the wheels?

All neccessary software and protocols are around for some year's for both
the installation and the groundstation:

- PACSAT Broadcast Protocol 
- DAMA (Demand Assigned Multiple Access)

Both have been proofed to be highly efficient and are well accepted..  The Broadcast 
protocol on nearly all PACSAT Satellites and DAMA on many terrestrial Digipeater within 
Europe..  MIR is nothing else than an high altitude digipeater where the "hidden station" 
problem is the largest problem...

While the groundstation only needs a different AX.25 compatible DAMA-Slave EPROM for 
the TNC, the station in the ISS or MIR hardware needs to be upgraded since standard 
TNC's do not support either the Broadcast or DAMA (master)  protocol.
A small Laptop computer (with the TNC in Kissmode) would have solved the problem,
there are also hardware solutions (TNC3 with TheNetNode, etc.) possible..
But with the demise of the MIR station it is probably too late anyway..

The above has been proposed by me earlier ;)

73s de Peter DB2OS