Tuesday, February 23, 2010

ROS - the chaos continues

Attempts to use the newly developed ROS weak signal mode are resulting in more chaos and frustration this morning as an increasing number of people pile on to the same frequencies. And attempts to decide frequencies to use with the mode seem to indicate total ignorance of other band users and modes. The latest list of recommended frequencies includes:

7.040 - which is going to interfere with the now long-established WSPR weak signal mode
10.140 - which will also interfere with WSPR's established frequency on that band
14.100.9 - which does not avoid the long established 24/7 packet network which has already complained about interference by this mode, and is also within the range reserved for beacons.

There are a total of three frequencies suggested for 30m, in ignorance of the fact that 30m is supposed to be used only for narrow band modes.

Someone responded to my earlier comment that a body like the IARU should decide which modes can work where, by saying that the IARU does not recommend frequencies for specific modes as that would interfere with experimentation. However I still think they should. When left to individual amateurs you simply get a fight between one group of people who don't have a clue and another group, users of existing modes, who have strong views about where they should NOT go. Without some overseeing arbitrator this will just end up as a mode war.

I think it is arguable that there just isn't room for a 2.2KHz wide weak signal mode on the HF bands at all. But if true, who is going to make that decision?

7 comments:

Andre said...

Personally, I think time would be much better spent re-promoting the DominoEX modes. Far more useful I think, a bit wider bandwidth then PSK31 in some cases, e.g. DominoEX 8 which has a similar speed to PSK31 with a bandwidth of just under 350 hz. Add on the FEC error correction and it will be far far more robust. Even without FEC, DominoEX is more resilient to multipath distortions than BPSK31. For even bertter long distant comms, use DominoEX 4 or DominoEX 5.
Check this mode out, I think operators should take it a bit more seriously.
The only times I have ever seen it in use is by preplanned skeds.
There is no need really, DominoEX is very easy to tune, you don't even need to be fully on the signal.

Just my pennies worth.

73

André - M0JEK

g4ilo said...

I agree. We hams love re-inventing the wheel. I suppose it goes with the territory. People like to design and build their own circuit instead of just copying someone else's.

Some people more knowledgeable than me are saying that the encoding used by ROS should allow more than one QSO to take place on the same frequency without interfering. If so that is a new and interesting development. But it doesn't seem to work like that in my experience.

Ultimately the success of any digital mode will depend on whether it achieves "critical mass" of getting enough users to make it always possible to make interesting contacts. RTTY has that. PSK31 has that. WSPR has that (although you can't make contacts with it.) But many other digital modes have their moment of glory and then fade into oblivion, regardless of their merits.

2E0HTS Simon said...

Hi Julian, just to let you know, I have just put the HF propagation widget on my blog.

Thanks a lot! Very nice widget indeed, keep up the good work.

Simon - 2E0HTS

Anonymous said...

Perhaps there should be a narrow window in several bands designated for experimental modes. If a mode actually catches on and proves to have definite advantages over other existing modes, then the issue of more permanent center frequencies could be discussed.

As you say, so many digital modes come and go, but while they are busy trying to establish themselves, they can cause quite a bit of havoc.

g4ilo said...

Yes, I think that would be a very good idea. I'm all for experimentation, but a mode needs to justify its existence before all and sundry should be allowed to use it. If every ham hacker invented their own mode just because they were bored one wet weekend it would get ridiculous.

Howard said...

The band plans are advisory and based upon current useage/activity. As the spectrum allocation for hams is fixed the reality is that there needs to be give and take if any experimentation is to take place. On the current band plans there is practically no allocation for experimentation and use of new modes which is highly restrictive and leads to users believing that their favourite mode has some priority ad infinitum. That attitude will only lead to hams ignoring band plans and create long term chaos. We have already seen how quickly some wish to jump on the "new mode users are a problem" band wagon in regard to ROS and the parochial attitude of some. Maybe it is time for a total rethink of band plan design?

g4ilo said...

To be honest, Howard, I think new mode users are a problem, because they come on using some bit of software that can only decode one mode, and because they can't read anyone else's signal they think the frequency is clear and cause QRM. In fact I even heard ROS users calling on top of other ROS users. I think the fact that it is digital communication detaches some users from what is going on so they don't connect clicking the Transmit button with causing QRM as they would pressing the Mic PTT over someone else's QSO.

The problem is the current dumbed down licensing regime has led people into the hobby who don't understand what they are doing. They know about computers so they download a bit of software and start to use it without trying to understand how the new mode works and what it was intended to be used for. ROS was supposed to be a weak signal mode but people are using it for inter-Europe macro exachange QSOs they could easily do using PSK31 and one twentieth the bandwidth.

If this is what the current band planning regime allows for then it needs to be changed, and I am going to be a vocal advocate for such change from now on. Experimentation is all very well but the situation where any Tom, Dick or Jose can invent a new mode, give away the software and cause chaos among existing digital mode users serves no good purpose whatever. I'm sorry if you don't agree with me.