Re: Changelog

Mike Zingman - N4IRR

Hello Waldek,

So, this is a BIG topic which covers several ways you may want to use the DVSwitch components.  The multiple transmit ports in general will allow you to have a much richer assortment of networks/modes bridged.  We will cover this is a very long message to come later.

The YSF change was actually done a while ago (before multi-ports), but did not get released until this last build.  Its original intent was to allow both wide and narrow YSF variants to be bridged to another mode.  As you may understand, MB can only bridge like modes together and all others must be transcoded before they can be bridged.  What this addition lets you do is to have BOTH a like mode bridge AND a transcoded bridge at the same time.  This is mostly unique to YSF, but has other uses as well.

So lets take an example DMR <--> YSF bridge.  Before the last release you could bridge the AMBE directly between the two modes and all would work well.  However, if a transmission on YSF wide was seen, the bridge would drop those voice packets since they were not of the proper data type for DMR.  Now you "could" have transcoded ALL (narrow and wide) and then re-encoded them, but this is a bad solution because of the loss of quality.

Now, what we can do is this:
DMR <--- > YSFN (direct mode bridge)
DMR <-- AB_AMBE <-- AB_IMBE <-- YSFW (transcoded bridge)

The only change you need is to define the TXWidePort to point at AB_IMBE and make the AB_AMBE point to the same port as the direct mode bridge.  The above diagram looks like two separate bridge instances, but it is not!  There is an an instance of MB and two instances of AB.  That is all.  The rest is just port mapping.

I did not use any port numbers in my example on purpose.  They do not matter.  As long as they match on each side.  So you "could"
DMR = 30001
YSFN = 3002
AB_AMBE = 3003
AB_IMBE = 3004
YSFW = 3005

I do not care what the numbers as long as the RX port for each mode is unique and the transmit ports match it.  Lets follow the data as it moves from mode to mode.  First the like modes are simple.  A transmission on DMR will be exported to the YSFN listener and sent to the network.  Good.  Same for the reverse direction.  Now a YSFW transmission is sent to the TXWidePort.  AB_IMBE is listening to that port, gets the TLV, decodes it to PCM, sends it to AB_AMBE to encode into AMBE and then sends the TLV to the same YSFN port.  Done. And lastly, please notice that the transcode for YSFW to DMR is only one way.  Why?  Because 1) it would be bad to have both modes arrive at the same time and 2) It is not needed. The YSF radio will decode the narrow transmission just fine.

All of this was done with only a single transmit port for each mode defined.  In future posts we will discuss how multiple transmit ports adds to this discussion.

Hope this made some sense
73, Mike N4IRR

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