Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mp02.r1000.mx.aol.com (Internet Inbound) with ESMTP id BC2B3380000EF; Fri, 2 Sep 2011 19:34:34 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QzdEO-0005RZ-Nv for rs_out_1@blacksheep.org; Sat, 03 Sep 2011 00:33:04 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QzdEN-0005RQ-NQ for rsgb_lf_group@blacksheep.org; Sat, 03 Sep 2011 00:33:03 +0100 Received: from smtp5.freeserve.com ([193.252.22.151] helo=smtp6.freeserve.com) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QzdEL-0000Ql-9y for rsgb_lf_group@blacksheep.org; Sat, 03 Sep 2011 00:33:03 +0100 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3514.me.freeserve.com (SMTP Server) with ESMTP id 79BCE7000085 for ; Sat, 3 Sep 2011 01:32:55 +0200 (CEST) Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf3514.me.freeserve.com (SMTP Server) with ESMTP id 6D2247000088 for ; Sat, 3 Sep 2011 01:32:55 +0200 (CEST) Received: from AGB (unknown [2.26.29.204]) by mwinf3514.me.freeserve.com (SMTP Server) with SMTP id 034477000085 for ; Sat, 3 Sep 2011 01:32:54 +0200 (CEST) X-ME-UUID: 20110902233255135.034477000085@mwinf3514.me.freeserve.com Message-ID: <8343E1D319EE4CEFB7C9BD20AAF2BFFA@AGB> From: "Graham" To: References: In-Reply-To: Date: Sat, 3 Sep 2011 00:32:54 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 X-Antivirus: avast! (VPS 110902-0, 02/09/2011), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 0.2 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RCVD_ILLEGAL_IP=0.234 Subject: Re: LF: My thoughts on ROS Content-Type: multipart/alternative; boundary="----=_NextPart_000_00F1_01CC69D1.05820470" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.6 required=5.0 tests=HTML_20_30,HTML_MESSAGE, MISSING_OUTLOOK_NAME autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:483239904:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1dc1464e61680a0a1a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_00F1_01CC69D1.05820470 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Roger, All ROS HF /MF / Multi access ./ How did we get here ? Well as previously, the mode was designed as a low signal = data mode optimised for LF/MF , the origins are routed in the = early days of the ROS project, when un-wittingly Jose had = accurately described the function of the mode (then HF only) as , = shall was say 'dispersed spectrum' , which triggered an all too = well documented response =20 In the midst of all this the EU decided by the use of 'English' = to define the telegraphy channel maximum bandwidth for 500 as 100 = Hz , which, by 'syntax error' resulted in the authorisation of = 'narrow data modes' after a poll conducted on this reflector = over bandwidth allocation's I suggested to Jose , that a 100 (99) = Hz narrow mode would be usable on the as then ,new, 500 = allocations. Followed then was quite a interesting development path , being = actually able to use the experimental licence to conduct = 'experiments' , the mode was coded as MF-1 and MF-7 , 7 giving a = similar data rate to PSK31 with approx 12/15 dB lower s/n = performance. Initial tests had shown PSK31 to be virtually useless = on 500 , the MF-1 provided reliable decodes some -2 to -3dB = past the point wspr stopped decoding (tested on a stable 500 Khz = 350 mile day time path via delft) , where was I think the initial = QSO was with Jim using MF-7 , resulted in the first 'long' = data qso on 500 , which was also decoded in France .=20 Only lately was it pointed out, that the MF mode differed from = the HF mode, in that , 'dispersal' techniques are not used in the = data coding path, the reason being , s/n gain can only be realised = via bandwidth and 100 hz is not sufficient for the technique to = be applied .. so If you observe a MF beacon, the modulation = 'pattern' is repeated. The HF mode differs in that frequency 'dispersion' is controlled = by randomization as part of the data path , this affords improved = s/n performance over the HF > UHF path with wider frequency = tolerances , conventional processing is also deployed, as well as = FEC .. these techniques re common to other data modes , but as this = point 'we' enter the un-known as John call's it ! So in part answer to Roger's question , over multi access ,=20 There has been added a modification to the code routine , which = , by use of the call sign, causes a unique locking sequence to be = generated, use of which may be selected by the decode switch . the result being , that all stations may be decoded , but if = the call of a wanted / qso station is entered , then the = software will only enter the lock phase when that station is = detected . Use is made of the overheads in the transmission system, affording = the mode the ability to withstand 'data' collisions , hence more = than one station may simultaneously use the same frequency.. as = once locked, the digital recovery process , rejects 'non locked' = data as (HF) noise. Limitations exist as to signal levels etc = , but the skip distance experienced on HF has enabled the system = to function quite well. both the 2k and 500 Hz versions have = the feature , the 500Hz version suffering more from collisions = but still is quite functional=20 Multi access is therefore not available to the MF mode, but as = the mode is 100 hz wide , its quite possible to simply QSY , = the reasons for the defined channels are simply , that its not = possible to casually intercept a ros transmission, you have to = be on frequency and capture the lock sequence for the frame to = decode, it is in effect a packet data system , coupled with the = sub-audio and signal levels below the waterfall resolution , = invisible ros as Mal coined it , defined channel operation was = the only way to ensure decodes , wider AFC was possible but at = the expense of cpu loading, unlike most modes, the audio = frequency is 'fixed' mouse click/tune is not possible=20 In passing,=20 The display is slightly unique , the indicated levels are of = engineering significance , a limited user guide exists, the author = is the sole developer, there is remote internet access built in, = remote station configuration via the internet for remote beacon = operation , a 'msn' internet chat function is provided , cat = function for most radios , and a repeater function on band or = cross band . it is primarily a data communication mode , unlike = wspr which was developed as a auto reporting beacon mode.=20 Personally In have suggested that some HF frequency's for the MF = mode be defined as its performance in cross band qso with 80 = has been exceptional , however ... one day may be .. but we all = have dials hi=20 I hope that fills in the gap's to date ! 73 -G..=20 From: Roger Lapthorn=20 Sent: Friday, September 02, 2011 9:37 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: My thoughts on ROS Well, I agree with GM4SLV's comments on ROS, although my experience is = very limited and RX only so far. I have successfully decoded G0NDB, = G4WGT and GM4SLV on 500kHz.=20 Like Mal and John, I also found the user friendliness of the software = lacking: the array of dials presented is impressive but rather = meaningless apart from the one on the left dealing with audio level. The = dials may be meaningful to some. I appreciate this is a "one man job" = and very credible too, but the UI does seem less user friendly than WSPR = for example. The spots for other bands, are indeed annoying and irrelevant. I wanted = the spots for 500kHz to remain but these disappeared soon after = appearing. When I first fired up the software I had no idea what should = happen and there seemed little FAQ data to help understand things. Did = I miss the basic "getting started" user guide? Eventually bleeps = happened and signals appeared, but this was more by luck than plan. Unlike WSPR I am still confused about how several stations can operate = at the same in the same sub-band, although this may be my lack of = understanding. On 14MHz there seems to be 3 unique channels for ROS, so = does this mean on 500kHz there is just one? With WSPR there can be = around 200 stations happily co-existing in just 200Hz of band over an = hour or so because of time and frequency separation. In summary, I was pleased to give ROS a successful go the other night = (on RX) but I doubt I'll stick with it either. Like John P-G I'd like = to give some other weak signal FSK 2-way communication modes a go on 500 = and 136kHz.=20 73s Roger G3XBM On 2 September 2011 20:51, John P-G = wrote: LF, One of my objectives listed on my application for a NoV for 500kHz was = to assist other UK stations in their own experiments, acting as remote = eyes and ears, and it was in this role that I accepted Graham's request to = join him and others using ROS. The mode has had a huge amount of press - negative and positive - and being a one-person development (and closed source) is certain to be controversial. After installing the software on my NetBook (Samsung NC10 - the only Windows PC I had available) I was initially bewildered by the look, = feel and configuration of the beast. The continuous appearance of information relating to bands quite = unrelated to the band you've selected is annoying and, on the small screen of a NetBook, very distracting - taking up valuable window space. The MF mode, with it's 2 symbol rates, is nicely compact, in 100Hz bandwidth, and the modem seems very sensitive - often (on a quiet = band) giving 100% copy of signals that were inaudible in the speaker and invisible on a separate RX/waterfall (the netbook screen is too small = to allow me to use the ROS waterfall). In the presence of lightning static crashes I found it less sensitive, often failing to lock on weak signals, but coping only with those that were both audible and visible. As a QSO mode - yes it probably does very well, but the user interface = is awful - little documentation to get the casual user started - and the continuously and pointless spots of other bands is enough to drive one = to distraction - and there is no way of storing a sequence of spots on = the band you're operating on, which means you can't easily digest just who = has reported your last transmission before it disappears, replaced by a = spot on 50MHz... I am always interested in digimodes for QSOs, not just for beacons, = but ROS falls short, I'm afraid. Mal's reported problems with both ROS and WSPR decodes failing might = be more a problem with his computer - as most people manage to decode = WSPR signals from the very weakest (just visible) at -30dB up to the very strongest (bright white trace) at +10dB or more. Failure on stronger signals is generally a timing issue - soundcard sample rate errors - = and failure to decode in general is a PC clock timing issue - the PC = /MUST/ be synchronised to UTC - via NTP/Dimension 4 or whatever. Window's own inbuilt "network time sync" just isn't good enough. Now - anyone want to try some other datamode (FSK only, Class-E amp) = tests this weekend? For tonight I've got a CW beacon running on 501.5kHz but would be = happy to try a CW QSO if anyone hears me. Can't do x-band - no HF antenna.... Regards, John GM4SLV --=20 http://g3xbm-qrp.blogspot.com/ http://www.g3xbm.co.uk http://www.youtube.com/user/g3xbm https://sites.google.com/site/sub9khz/ ------=_NextPart_000_00F1_01CC69D1.05820470 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Roger, All
 
ROS HF /MF / Multi access ./ How  = did =20 we  get  here ?
 
Well  as  previously, = the =20 mode   was  designed as a   low =20 signal   data  mode  optimised  for  = LF/MF  ,=20 the  origins  are  routed  in the  early =20 days  of the  ROS  project, when  un-wittingly = Jose =20 had  accurately  described  the  function  of = the =20 mode  (then HF only) as , shall  was say 'dispersed = spectrum' ,=20 which  triggered  an  all  too  well =20 documented  response 
 
In the  midst of all  this = the  EU=20 decided  by the  use  of  'English'  to define=20 the  telegraphy channel  maximum bandwidth  for  = 500 =20 as  100 Hz , which, by 'syntax error'   = resulted in=20 the  authorisation  of  'narrow data  modes' =20  after a  poll  conducted on   this =20 reflector  over  bandwidth  allocation's  I = suggested=20 to  Jose , that  a  100  (99)  Hz  =20 narrow  mode  would be  usable  on the  as then = ,new,  500  allocations.
 
Followed  then was  quite a=20 interesting  development  path , being  = actually =20 able  to  use  the  experimental  = licence =20 to  conduct  'experiments'  , the  mode was =20 coded  as  MF-1  and  MF-7  , 7 giving a  = similar=20 data  rate to  PSK31 with   approx  12/15=20 dB  lower  s/n  performance. Initial  tests  had shown PSK31  to  = be =20 virtually useless  on 500 , the  MF-1  = provided =20 reliable  decodes  some  -2  to  -3dB  = past=20 the  point  wspr  stopped  decoding (tested on a = stable 500=20 Khz  350 mile day  time  path  via  = delft) , where=20 was  I think  the initial  QSO  was  with  = Jim  using  MF-7  , resulted in the  first =20 'long'   data  qso  on 500  , which was =20 also  decoded  in France .
 
Only   lately  was = it  pointed=20 out, that  the  MF mode  differed  from the  HF = mode,=20 in that , 'dispersal'  techniques  are not  used in=20 the  data  coding  path, the  reason being , s/n = gain=20 can  only  be  realised  via   = bandwidth =20 and  100  hz is not sufficient for the  technique = to  be=20 applied .. so  If you  observe  a   MF beacon,=20 the  modulation  'pattern' is  repeated.
 
The  HF  mode  = differs  in=20 that  frequency 'dispersion'  is  controlled by=20  randomization   as  part of=20 the  data  path , this affords  improved s/n =20 performance  over  the  HF > UHF  path = with =20 wider  frequency  tolerances  , conventional =20 processing  is  also  deployed, as well  as  = FEC ..=20 these techniques re  common to  other  data  = modes  ,=20 but as this point  'we'  enter  the  un-known = as  John=20 call's  it !
 
So  in part  answer to =20 Roger's  question  , over  multi  access , =
 
There  has been  added  = a =20 modification  to the  code   routine , which , = by  use=20 of the  call  sign, causes a  unique locking  = sequence =20 to  be  generated,  use of which  may  be  = selected  by  the decode  switch .
the result  being  , = that  all =20 stations  may  be  decoded  , but  if the  = call  of a  wanted / qso  station  is  = entered  ,=20 then the  software  will  only  enter the  = lock =20 phase  when that  station  is  detected = .
 
Use  is  made of the =20 overheads  in the  transmission system, = affording the  mode=20  the  ability  to  withstand   'data'=20 collisions , hence  more  than  one  = station  may=20 simultaneously  use the  same  frequency.. as once = locked,=20 the  digital  recovery process  , rejects  'non=20 locked'  data  as  (HF)  noise. Limitations  exist  as  to  = signal =20 levels  etc  , but  the  skip distance =20 experienced  on HF has  enabled  the  system = to =20 function  quite  well. both the   2k and  500 = Hz =20 versions  have  the  feature , the  500Hz =20 version  suffering  more  from  collisions  = but =20 still  is quite  functional
 
Multi  access  is  = therefore =20 not  available   to the MF mode, but  as  = the =20 mode  is  100 hz wide  , its  quite  = possible =20 to  simply  QSY , the  reasons  for the  = defined =20 channels  are  simply  , that  its not  = possible=20 to  casually  intercept  a  ros  = transmission, =20 you  have to  be  on  frequency  and  = capture=20 the  lock  sequence  for the  frame  to  = decode,=20 it  is  in effect  a  packet  data  system = ,=20 coupled  with the  sub-audio  and  signal  = levels =20 below  the  waterfall  resolution  , invisible  = ros  as Mal  coined  it  ,  defined = channel =20 operation    was the only  way to ensure  = decodes=20 ,  wider  AFC  was  possible  but  at = the =20 expense  of  cpu loading, unlike   most  modes, = the   audio frequency is  'fixed'  mouse =20 click/tune  is not  possible
 
In passing,
 
The   display  is  = slightly=20 unique , the indicated   levels  are  of  = engineering =20 significance , a limited  user  guide  exists, =  the =20 author  is  the  sole  developer, there  = is =20 remote  internet access built in, remote  station =20 configuration  via  the  internet for  remote=20 beacon  operation = , a  'msn'   internet=20 chat  function  is  provided ,  cat  = function =20 for  most radios  , and a  repeater function  on = band =20 or  cross  band . it is  primarily a  data =20 communication  mode , unlike  wspr  which  was  = developed  as a auto  reporting  beacon mode. =
 
Personally In have  = suggested  that =20 some  HF frequency's  for the  MF mode  be defined=20  as   its  performance  in cross  = band  qso=20 with  80  has been   exceptional , = however  ...=20 one  day may  be  .. but  we all  have =20 dials  hi
 
I hope  that  fills  = in =20 the  gap's to  date !
 
73  -G..
 
 

From: Roger Lapthorn
Sent: Friday, September 02, 2011 9:37 PM
To: rsgb_lf_group@blacksheep.org= =20
Subject: Re: LF: My thoughts on ROS

Well, I agree with GM4SLV's comments on ROS, although my=20 experience is very limited and RX only so far. I have successfully = decoded=20 G0NDB, G4WGT and GM4SLV on 500kHz.

Like Mal and John, I also = found the=20 user friendliness of the software lacking: the array of dials presented = is=20 impressive but rather meaningless apart from the one on the left dealing = with=20 audio level. The dials may be meaningful to some. I appreciate this is a = "one=20 man job" and very credible too, but the UI does seem less user friendly = than=20 WSPR for example.

The spots for other bands, are indeed annoying = and=20 irrelevant.  I wanted the spots for 500kHz to remain but these = disappeared=20 soon after appearing.  When I first fired up the software I had no = idea=20 what should happen and there seemed little FAQ data to help understand=20 things.  Did I miss the basic "getting started" user guide? = Eventually=20 bleeps happened and signals appeared, but this was more by luck than=20 plan.

Unlike WSPR I am still confused about how several stations = can=20 operate at the same in the same sub-band, although this may be my lack = of=20 understanding. On 14MHz there seems to be 3 unique channels for ROS, so = does=20 this mean on 500kHz there is just one? With WSPR there can be around 200 = stations happily co-existing in just 200Hz of band over an hour or so = because of=20 time and frequency separation.

In summary, I was pleased to give = ROS a=20 successful go the other night (on RX) but I doubt I'll stick with it=20 either.  Like John P-G I'd like to give some other weak signal FSK = 2-way=20 communication modes a go on 500 and 136kHz.

73s
Roger=20 G3XBM


On 2 September 2011 20:51, John P-G <gm4slv@sighthound.demon.co.= uk>=20 wrote:
LF,

One of my objectives listed on my = application for=20 a NoV for 500kHz was to
assist other UK stations in their own = experiments,=20 acting as remote eyes
and ears, and it was in this role that I = accepted=20 Graham's request to join
him and others using ROS.

The mode = has had=20 a huge amount of press - negative and positive - and
being a = one-person=20 development (and closed source) is certain to=20 be
controversial.

After installing the software on my = NetBook=20 (Samsung NC10 - the only
Windows PC I had available) I was = initially=20 bewildered by the look, feel
and configuration of the = beast.

The=20 continuous appearance of information relating to bands quite = unrelated
to=20 the band you've selected is annoying and, on the small screen of = a
NetBook,=20 very distracting - taking up valuable window space.

The MF = mode, with=20 it's 2 symbol rates, is nicely compact, in 100Hz
bandwidth, and the = modem=20 seems very sensitive - often (on a quiet band)
giving 100% copy of = signals=20 that were inaudible in the speaker and
invisible on a separate = RX/waterfall=20 (the netbook screen is too small to
allow me to use the ROS=20 waterfall).

In the presence of lightning static crashes I found = it less=20 sensitive,
often failing to lock on weak signals, but coping only = with=20 those that
were both audible and visible.

As a QSO mode - = yes it=20 probably does very well, but the user interface is
awful - little=20 documentation to get the casual user started - and the
continuously = and=20 pointless spots of other bands is enough to drive one = to
distraction - and=20 there is no way of storing a sequence of spots on the
band you're = operating=20 on, which means you can't easily digest just who has
reported your = last=20 transmission before it disappears, replaced by a spot
on = 50MHz...

I=20 am always interested in digimodes for QSOs, not just for beacons, = but
ROS=20 falls short, I'm afraid.

Mal's reported problems with both ROS = and WSPR=20 decodes failing might be
more a problem with his computer - as most = people=20 manage to decode WSPR
signals from the very weakest (just visible) = at -30dB=20 up to the very
strongest (bright white trace) at +10dB or more. = Failure on=20 stronger
signals is generally a timing issue - soundcard sample = rate errors=20 - and
failure to decode in general is a PC clock timing issue - the = PC=20 /MUST/ be
synchronised to UTC - via NTP/Dimension 4 or whatever. = Window's=20 own
inbuilt "network time sync" just isn't good = enough.


Now -=20 anyone want to try some other datamode (FSK only, Class-E amp) = tests
this=20 weekend?

For tonight I've got a CW beacon running on 501.5kHz = but would=20 be happy to
try a CW QSO if anyone hears me. Can't do x-band - no = HF=20 = antenna....

Regards,

John
GM4SLV



--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
https://sites.google.com/site/sub9khz/


=
= = ------=_NextPart_000_00F1_01CC69D1.05820470--