VARA HF Modem Speeds


Tony
 

All:

I observed an unusually fast file transfer while using VARA on 40 meters today (see below). It's not uncommon to see speeds of 15,000 to 20,000 bytes/minute when the band is stable, but today's observation shows that faster speeds are possible under the right conditions.

I should mention that the 30K b/m speed was recorded while receiving a 30K image.

Tony -K2MO



*** Winlink Vara Connection to KC8YJJ @ 2021/01/17 20:09:59  USB Dial: 7101.000
*** Station Bearing: 268,  Range: 393 miles
RMS Trimode 1.3.36.0
K2MO has 120 minutes remaining with KC8YJJ
{SFI = 078 On 2021-01-17 20:00 UTC}
[WL2K-5.0-B2FWIHJM$]
;PQ: 44766187
CMS via KC8YJJ >
   ;FW: K2MO
   [RMS Express-1.5.34.0-B2FHM$]

   ;PR: 17655197
   ; KC8YJJ DE K2MO (FN30JV)
   FF
;PM: K2MO 36Y27O2YLIPH 30887 73guddx@gmail.com ---
FC EM 36Y27O2YLIPH 32990 30887 0
F> C5
   FS Y
*** Receiving 36Y27O2YLIPH
*** 36Y27O2YLIPH - 33005/30899 bytes received
*** Bytes: 31145,  Time: 01:03,  bytes/minute: 29618
   FF
FQ
*** --- End of session at 2021/01/17 20:11:49 ---
*** Messages sent: 0.  Total bytes sent: 0,  Time: 01:49, bytes/minute: 0
*** Messages Received: 1.  Total bytes received: 31145,  Total session time: 01:49,  bytes/minute: 17035
*** Disconnected from Winlink RMS: KC8YJJ @ 2021/01/17 20:11:56
*** Session: 1.9 min;  Avg Throughput: 15552 Bytes/min;   1 Min Peak Throughput: 15552 Bytes/min


Andrew OBrien
 

By the way Tony, I have sent you a few emails via your Winlink  address lately and each time winlink says nop such address.

Andy K3UK 

On Sun, Jan 17, 2021 at 5:45 PM Tony <73GUDDX@...> wrote:
All:

I observed an unusually fast file transfer while using VARA on 40 meters
today (see below). It's not uncommon to see speeds of 15,000 to 20,000
bytes/minute when the band is stable, but today's observation shows that
faster speeds are possible under the right conditions.

I should mention that the 30K b/m speed was recorded while receiving a
30K image.

Tony -K2MO



*** Winlink Vara Connection to KC8YJJ @ 2021/01/17 20:09:59  USB Dial:
7101.000
*** Station Bearing: 268,  Range: 393 miles
RMS Trimode 1.3.36.0
K2MO has 120 minutes remaining with KC8YJJ
{SFI = 078 On 2021-01-17 20:00 UTC}
[WL2K-5.0-B2FWIHJM$]
;PQ: 44766187
CMS via KC8YJJ >
    ;FW: K2MO
    [RMS Express-1.5.34.0-B2FHM$]

    ;PR: 17655197
    ; KC8YJJ DE K2MO (FN30JV)
    FF
;PM: K2MO 36Y27O2YLIPH 30887 73guddx@... ---
FC EM 36Y27O2YLIPH 32990 30887 0
F> C5
    FS Y
*** Receiving 36Y27O2YLIPH
*** 36Y27O2YLIPH - 33005/30899 bytes received
*** Bytes: 31145,  Time: 01:03,  bytes/minute: 29618
    FF
FQ
*** --- End of session at 2021/01/17 20:11:49 ---
*** Messages sent: 0.  Total bytes sent: 0,  Time: 01:49, bytes/minute: 0
*** Messages Received: 1.  Total bytes received: 31145,  Total session
time: 01:49,  bytes/minute: 17035
*** Disconnected from Winlink RMS: KC8YJJ @ 2021/01/17 20:11:56
*** Session: 1.9 min;  Avg Throughput: 15552 Bytes/min;   1 Min Peak
Throughput: 15552 Bytes/min







Tony
 

Andy:

Had to edit my whitelist to include gmail addresses. 

Please try again when you get the chance.

Tony -K2MO



On 1/17/2021 6:36 PM, Andrew OBrien wrote:
By the way Tony, I have sent you a few emails via your Winlink  address lately and each time winlink says nop such address.

Andy K3UK 

On Sun, Jan 17, 2021 at 5:45 PM Tony <73GUDDX@...> wrote:
All:

I observed an unusually fast file transfer while using VARA on 40 meters
today (see below). It's not uncommon to see speeds of 15,000 to 20,000
bytes/minute when the band is stable, but today's observation shows that
faster speeds are possible under the right conditions.

I should mention that the 30K b/m speed was recorded while receiving a
30K image.

Tony -K2MO



*** Winlink Vara Connection to KC8YJJ @ 2021/01/17 20:09:59  USB Dial:
7101.000
*** Station Bearing: 268,  Range: 393 miles
RMS Trimode 1.3.36.0
K2MO has 120 minutes remaining with KC8YJJ
{SFI = 078 On 2021-01-17 20:00 UTC}
[WL2K-5.0-B2FWIHJM$]
;PQ: 44766187
CMS via KC8YJJ >
    ;FW: K2MO
    [RMS Express-1.5.34.0-B2FHM$]

    ;PR: 17655197
    ; KC8YJJ DE K2MO (FN30JV)
    FF
;PM: K2MO 36Y27O2YLIPH 30887 73guddx@... ---
FC EM 36Y27O2YLIPH 32990 30887 0
F> C5
    FS Y
*** Receiving 36Y27O2YLIPH
*** 36Y27O2YLIPH - 33005/30899 bytes received
*** Bytes: 31145,  Time: 01:03,  bytes/minute: 29618
    FF
FQ
*** --- End of session at 2021/01/17 20:11:49 ---
*** Messages sent: 0.  Total bytes sent: 0,  Time: 01:49, bytes/minute: 0
*** Messages Received: 1.  Total bytes received: 31145,  Total session
time: 01:49,  bytes/minute: 17035
*** Disconnected from Winlink RMS: KC8YJJ @ 2021/01/17 20:11:56
*** Session: 1.9 min;  Avg Throughput: 15552 Bytes/min;   1 Min Peak
Throughput: 15552 Bytes/min








Andrew O'Brien
 

OK , will try again.  I have been using my Winlink address.

Andy 

On Sun, Jan 17, 2021 at 9:22 PM Tony <73GUDDX@...> wrote:
Andy:

Had to edit my whitelist to include gmail addresses. 

Please try again when you get the chance.

Tony -K2MO



On 1/17/2021 6:36 PM, Andrew OBrien wrote:
By the way Tony, I have sent you a few emails via your Winlink  address lately and each time winlink says nop such address.

Andy K3UK 

On Sun, Jan 17, 2021 at 5:45 PM Tony <73GUDDX@...> wrote:
All:

I observed an unusually fast file transfer while using VARA on 40 meters
today (see below). It's not uncommon to see speeds of 15,000 to 20,000
bytes/minute when the band is stable, but today's observation shows that
faster speeds are possible under the right conditions.

I should mention that the 30K b/m speed was recorded while receiving a
30K image.

Tony -K2MO



*** Winlink Vara Connection to KC8YJJ @ 2021/01/17 20:09:59  USB Dial:
7101.000
*** Station Bearing: 268,  Range: 393 miles
RMS Trimode 1.3.36.0
K2MO has 120 minutes remaining with KC8YJJ
{SFI = 078 On 2021-01-17 20:00 UTC}
[WL2K-5.0-B2FWIHJM$]
;PQ: 44766187
CMS via KC8YJJ >
    ;FW: K2MO
    [RMS Express-1.5.34.0-B2FHM$]

    ;PR: 17655197
    ; KC8YJJ DE K2MO (FN30JV)
    FF
;PM: K2MO 36Y27O2YLIPH 30887 73guddx@... ---
FC EM 36Y27O2YLIPH 32990 30887 0
F> C5
    FS Y
*** Receiving 36Y27O2YLIPH
*** 36Y27O2YLIPH - 33005/30899 bytes received
*** Bytes: 31145,  Time: 01:03,  bytes/minute: 29618
    FF
FQ
*** --- End of session at 2021/01/17 20:11:49 ---
*** Messages sent: 0.  Total bytes sent: 0,  Time: 01:49, bytes/minute: 0
*** Messages Received: 1.  Total bytes received: 31145,  Total session
time: 01:49,  bytes/minute: 17035
*** Disconnected from Winlink RMS: KC8YJJ @ 2021/01/17 20:11:56
*** Session: 1.9 min;  Avg Throughput: 15552 Bytes/min;   1 Min Peak
Throughput: 15552 Bytes/min









--
Andy


Rick Muething
 

Tony/All,

VARA is truly a very capable protocol and throughput on HF can exceed 20 K bytes/minute over some channels.   Tom Whiteside N5TW of the Winlink development team recently completed an extensive comparison of several HF and VHF/UHF ARQ protocols over a wide range of S:N and Multipath propagation using a new low-cost HF/VHF Ionospheric Simulator.  This kind of testing allows accurate testing with repeatable data which is often difficult or impossible to duplicate over the air. Those interested in seeing details on Tom Whiteside's N5TW simulation effort and protocol comparisons  should check out https://winlink.org/content/ionos_simulator

73,

Rick Muething, KN6KB

On 1/17/2021 5:45 PM, Tony wrote:
All:

I observed an unusually fast file transfer while using VARA on 40 meters today (see below). It's not uncommon to see speeds of 15,000 to 20,000 bytes/minute when the band is stable, but today's observation shows that faster speeds are possible under the right conditions.

I should mention that the 30K b/m speed was recorded while receiving a 30K image.

Tony -K2MO



*** Winlink Vara Connection to KC8YJJ @ 2021/01/17 20:09:59  USB Dial: 7101.000
*** Station Bearing: 268,  Range: 393 miles
RMS Trimode 1.3.36.0
K2MO has 120 minutes remaining with KC8YJJ
{SFI = 078 On 2021-01-17 20:00 UTC}
[WL2K-5.0-B2FWIHJM$]
;PQ: 44766187
CMS via KC8YJJ >
   ;FW: K2MO
   [RMS Express-1.5.34.0-B2FHM$]

   ;PR: 17655197
   ; KC8YJJ DE K2MO (FN30JV)
   FF
;PM: K2MO 36Y27O2YLIPH 30887 73guddx@gmail.com ---
FC EM 36Y27O2YLIPH 32990 30887 0
F> C5
   FS Y
*** Receiving 36Y27O2YLIPH
*** 36Y27O2YLIPH - 33005/30899 bytes received
*** Bytes: 31145,  Time: 01:03,  bytes/minute: 29618
   FF
FQ
*** --- End of session at 2021/01/17 20:11:49 ---
*** Messages sent: 0.  Total bytes sent: 0,  Time: 01:49, bytes/minute: 0
*** Messages Received: 1.  Total bytes received: 31145,  Total session time: 01:49,  bytes/minute: 17035
*** Disconnected from Winlink RMS: KC8YJJ @ 2021/01/17 20:11:56
*** Session: 1.9 min;  Avg Throughput: 15552 Bytes/min;   1 Min Peak Throughput: 15552 Bytes/min





Graham
 

Its unclear as to  why the  simulator results where  so  wrong  and now  so  right , applying to  just one mode, where as   other's  remain, apparently,  unaffected  ?

What was identified as  causing the  discrepancy  ?

73 -Graham
g0nbd


Andrew O'Brien
 

The article is very interesting
Andy K3UK

On Thu, Jan 21, 2021 at 10:42 AM Graham <g0nbd@...> wrote:
Its unclear as to  why the  simulator results where  so  wrong  and now  so  right , applying to  just one mode, where as   other's  remain, apparently,  unaffected  ?

What was identified as  causing the  discrepancy  ?

73 -Graham
g0nbd



--
Andy


Andrew OBrien
 

and I will add ...  The pactor modes still hold up as very effective under various conditions but I think it is ironic that after the written and verbal "beating" that Jose received for his ROS mode software ,  Jose deserves huge credit and thanks for his VARA work.  The results mentioned in the article are truly outstanding! Both HF and FM VARA .  Wide VARA and Narrow VARA. The article appropriately references Rick's pioneering work with WINMOR and ARDOP.  I especially enjoyed the early WINMOR experiments on air.

Andy K3UK 


Graham
 

Yes , Quite agree  Andy ,

The  vara  modem  started  years  before it  broke the  surface , in many variations,  the  fully  odfm version was  and remains radical ,  the  mfsk  front end to the  HF version, signalled the  limitations to  psk  modulation .. perhaps echoing the  MT63 , progression to  Olivia in terms of  s/n  

In reality , 'we'  as in data  mode users  are  now  10 years  behind  the  times , Ros HF , introduced , 'efficient   use of  bandwidth'  whilst maintaining QSO integrity and equal channel  access  for  users at  minimal s/n levels . 

To day , as already commented ,  non  coexisting  transmission formats  are  spreading along the  dial  

Only  need  to  observe the  psk-map  11  meter  band , when there  is a  opening ,  to  observe , the  traffic level  
supported in a  single  voice  channel  , by non ham users , demonstrating the  validity of the  designe .. and the far sightedness of the  SS Trial group  , who  also  came under  fire , 

73-Graham
g0nbd


Rick Muething
 

Graham,

I think I missed the first part of the discussion.  Is this referring to the Winlink/ARSFI  Ionos Simulator project/simulator?

There is a pretty complete write-up of the effort and examples of simulation runs at:

https://winlink.org/content/ionos_simulator

Tom W. N5TW,  Tom Lafleur KA6IQA  and I were working on the effort most of last year during the development and verification of the simulator and testing  common popular protocols.

If interested I can provide more detail.

73,

Rick Muething, KN6KB Winlink Development Team.

On 1/21/2021 10:42 AM, Graham wrote:
Its unclear as to  why the  simulator results where  so  wrong  and now  so  right , applying to  just one mode, where as   other's  remain, apparently,  unaffected  ?

What was identified as  causing the  discrepancy  ?

73 -Graham
g0nbd


Graham
 

Rick 

I , just noticed the  P4  and V4 speeds , had , in effect  reversed, where as the  other  modes , look to be similar ,

interesting  would be  comparison of  OLIVIA  and  ROS-HF-4  modes 

P4 is  used on HF out side the  part97  regulatory area , various on air comparisons  , have been  made , one  ive posted below 
Test via HB9AVK
   592 km  7.050  , shows a  11:7   compound advantage , test '2' shows  P4  advantage , 10 seconds in  120 
link survival, V4  appears also to offer advantage ?

In the  simulation, the  audio is presented  directly ? ,  Vara has been  developed  using live  links, 
notably , recent versions are  bandwidth  tailored to maximise  use of available bandwidth , peak ratios also have been  
dynamically matched .. all these contribute to  optimisation 


73 -Graham
g0nbd




COMPARE VARA and PACTOR4  upload via Gateway HB9AK

 

Test via HB9AVK   592 km  7,050 MHz DIAL

 

 

Term 1

 

*** Completed send of VARA message JE2O4B0QBRP2

*** Sent 1 message.  Bytes: 20230,  Time: 01:03,  bytes/minute: 19030

 

*** Completed send of Pactor message MATG09PBPW98

*** Sent 1 message.  Bytes: 20218,  Time: 03:11,  bytes/minute: 6332

 

Term 2

 

*** Completed send of VARA message 6Z4SZQFPRIJL

*** Sent 1 message.  Bytes: 20213,  Time: 02:16,  bytes/minute: 8870

 

*** Completed send of Pactor message 2XWY9G2MCS0N

*** Sent 1 message.  Bytes: 20219,  Time: 02:07,  bytes/minute: 9517

 

Term 3

 

*** Completed send of VARA message TC67GB6RLZ1S

*** Sent 1 message.  Bytes: 20213,  Time: 02:46,  bytes/minute: 7301

 

*** Completed send of Pactor message Z6PSHUFB8HZ3

*** Sent 1 message.  Bytes: 20217,  Time: 02:21,  bytes/minute: 8573

 

Term 4

 

*** Completed send of VARA message K9K11XBW9D3F Vara WL2K

*** Sent 1 message.  Bytes: 20215,  Time: 02:37,  bytes/minute: 7692

 

*** Completed send of Pactor message 58KVLSL4OUSX    fast QRM Disconnecting Timeout

*** Sent 1 message.  Bytes: 20219,  Time: 05:24,  bytes/minute: 3740

 

Result:

 

Term

MODE

Total bytes sent

Time

bytes/minute

Message ID

 

1

VARA

20230

01:03

19030

JE2O4B0QBRP2

 

 

P4

20218

03:11

6332

MATG09PBPW98

 

 

 

 

 

 

 

 

2

VARA

20213

02:16

8870

6Z4SZQFPRIJL

 

 

P4

20219

02:07

9517

2XWY9G2MCS0N

 

 

 

 

 

 

 

 

3

VARA

20213

02:46

7301

Z6PSHUFB8HZ3

 

 

P4

20217

02:21

8573

 

 

 

 

 

 

 

 

 

4

VARA

20215

02:37

7692

K9K11XBW9D3F

 

 

P4

20219

05:24

3740

58KVLSL4OUSX

 

 

 

 

 

 

 

 

 

 

 

 

VARA Mean Value:  10723

P4 Mean Value:       7040


Rick Muething
 

Graham,

During the development of the Simulator there were many mods to the code doing the audio processing.  Specifically my initial code (and some of the initial tests) did not correctly model the multipath (created by the delay and modulation (with a randomized Real + Imaginary veector) of the audio. This was found to be due in part to problems with the C++ implementation of the narrow band (~3 Hz) multipath filters which were implemented using IIR filters.   It took a couple of months to get the implementation to match/track other simulators (hardware and software).  Also the latest simulator firmware versions (2.03)  gave users the option of using 1 path (WGN), 2 path multipath or a 4 path multipath. The results published in Tom W's testing writeup:

https://winlink.org/sites/default/files/downloads/a_winlink_digital_mode_performance_comparison_based_on_the_ionis_sim_hf_vhf_channel_simulator_-_november_2_2020_0.pdf

use only 2 path multipath (two I + Q paths) along with the most recent revisions of VARA, Pactor 4 and the Winlink Express client program.  Some mods in the Winlink  Express modem drivers allowed slightly (10-15%) more throughput in both Pactor 4 and VARA.  VARA 2.8 KHz BW was not available for testing.  That should allow slightly faster throughput at High S:N levels (> 25 dB) .  In practice however it is rare (without Linears or high gain antennas) to often see digital connections > 25 dB  S:N.

The simulator of course does not know or care what protocol it is processing it simply takes the audio from the modem/sound card,  checks to make sure it is not overdriving the simulator ,and processes the audio at the requested simulator bandwidth (300-3300 Hz   or 300-6300 Hz)  and then mixes WGN at the requested S:N and the desired level of multipath (using the recommended path delay values by the CCIR/ITU ) .  The extensive testing showed repeatable results [net throughputs for long (5-15 minute) ARQ sessions] for all protocols.

The Ionos Simulator also computes and displays the Crest Factor which can help determine the optimum drive level for the transmitter.  With very low crest factors (< 2:1 or < 3dB) it is quite possible to drive most amateur SSB transmitters  to exceed its thermal limits even if it is not driven to maximum rated PEP.  With high crest factors (>5-6 dB) most amateur transmitters will be PEP limited before thermal limited and this will result in lower net Energy per bit and therefore lower throughput for a given PEP drive level.

The main value of the simulator is that it allows duplicating statistically similar paths (S:N and multipath) that are almost impossible to do using using over the air testing. This is why they have been used extensively in testing and characterizing protocols such as Mil STD 188 and STANAG.

73,

Rick KN6KB


On 1/22/2021 9:17 AM, Graham wrote:

Rick 

I , just noticed the  P4  and V4 speeds , had , in effect  reversed, where as the  other  modes , look to be similar ,

interesting  would be  comparison of  OLIVIA  and  ROS-HF-4  modes 

P4 is  used on HF out side the  part97  regulatory area , various on air comparisons  , have been  made , one  ive posted below 
Test via HB9AVK
   592 km  7.050  , shows a  11:7   compound advantage , test '2' shows  P4  advantage , 10 seconds in  120 
link survival, V4  appears also to offer advantage ?

In the  simulation, the  audio is presented  directly ? ,  Vara has been  developed  using live  links, 
notably , recent versions are  bandwidth  tailored to maximise  use of available bandwidth , peak ratios also have been  
dynamically matched .. all these contribute to  optimisation 


73 -Graham
g0nbd




COMPARE VARA and PACTOR4  upload via Gateway HB9AK

 

Test via HB9AVK   592 km  7,050 MHz DIAL

 

 

Term 1

 

*** Completed send of VARA message JE2O4B0QBRP2

*** Sent 1 message.  Bytes: 20230,  Time: 01:03,  bytes/minute: 19030

 

*** Completed send of Pactor message MATG09PBPW98

*** Sent 1 message.  Bytes: 20218,  Time: 03:11,  bytes/minute: 6332

 

Term 2

 

*** Completed send of VARA message 6Z4SZQFPRIJL

*** Sent 1 message.  Bytes: 20213,  Time: 02:16,  bytes/minute: 8870

 

*** Completed send of Pactor message 2XWY9G2MCS0N

*** Sent 1 message.  Bytes: 20219,  Time: 02:07,  bytes/minute: 9517

 

Term 3

 

*** Completed send of VARA message TC67GB6RLZ1S

*** Sent 1 message.  Bytes: 20213,  Time: 02:46,  bytes/minute: 7301

 

*** Completed send of Pactor message Z6PSHUFB8HZ3

*** Sent 1 message.  Bytes: 20217,  Time: 02:21,  bytes/minute: 8573

 

Term 4

 

*** Completed send of VARA message K9K11XBW9D3F Vara WL2K

*** Sent 1 message.  Bytes: 20215,  Time: 02:37,  bytes/minute: 7692

 

*** Completed send of Pactor message 58KVLSL4OUSX    fast QRM Disconnecting Timeout

*** Sent 1 message.  Bytes: 20219,  Time: 05:24,  bytes/minute: 3740

 

Result:

 

Term

MODE

Total bytes sent

Time

bytes/minute

Message ID

 

1

VARA

20230

01:03

19030

JE2O4B0QBRP2

 

 

P4

20218

03:11

6332

MATG09PBPW98

 

 

 

 

 

 

 

 

2

VARA

20213

02:16

8870

6Z4SZQFPRIJL

 

 

P4

20219

02:07

9517

2XWY9G2MCS0N

 

 

 

 

 

 

 

 

3

VARA

20213

02:46

7301

Z6PSHUFB8HZ3

 

 

P4

20217

02:21

8573

 

 

 

 

 

 

 

 

 

4

VARA

20215

02:37

7692

K9K11XBW9D3F

 

 

P4

20219

05:24

3740

58KVLSL4OUSX

 

 

 

 

 

 

 

 

 

 

 

 

VARA Mean Value:  10723

P4 Mean Value:       7040