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Tooway Installation - about to install two systems

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Sean_Williams
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Jul 18th, 2008 at 11:34am  
Hello The Forum
a couple of us are about to self-install having gained the necessary confidence after reading the posts by Cambrian - thanks Tony for your information and advice so far ;O)

In fact, our two locations are only a few miles from Cambrian in West Wales so there's going to be quite a 'cluster'!

At this stage, I have one seemingly important question to ask: Bentley Walker say the cables between modem and dish have to be 30m long, but they couldn't tell me why. However, Cambrian says it's so the modem doesn't fry the TRIA.
Is this really the case - it seems a little odd (I say this, knowing almost nothing about two-way satellite installations!) ?
If it is correct, would I be right in making these two assumptions:
1. As we are not under the main beam of the transponders here in Wales, this length could be reduced

2. It's only the TX side that could be fried, so it would be OK to have the TX cable at (say) 30m, but the RX cable as short as possible to facilitate the maximum downstream signal strength. (we're using 2 x single WF100 cables as it was half the price)

Or have I got this all rear-about-face?

TIA
Regards
Sean
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Eric Johnston
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Reply #1 - Jul 18th, 2008 at 12:24pm  
Regarding cables, I would do what BW say or discuss with them.

If the cables are pre-terminated, keeping them at their full length avoids you having to remake the terminations.    Making good F connections is a skilled job.  It looks easy but the fact is that most in service VSAT faults are due to poor F connector workmanship.   A special tool is needed if top quality axial crimp type F connectors are used.

On the receive side, the length of the cable, unless extremely long, will make negligible difference to the signal to noise ratio.  Longer cables cause more attenuation but this reduces both the wanted signal and the noise level simultaneously.  It is only with extremely long cables, in excess of 30m, that a reduction in signal to noise ratio may be detectable.

I don't know if Tooway is sensitive to short receive cables.
...
These are the TooWay cables provided by El Molino in Spain.

On the transmit site the transmit signal level into the BUC/TRIA is really critical.   If BW say to leave the cable length at 30m then do this.  The modem is pre-programmed before delivery with a range of transmit power levels and frequencies to explore automatically and these will have been set assuming a specified transmit cable loss.   In service, the modem output level needs to be set to match the transmit bit rate, the uplink propagation loss (varies dynamically with the weather) distance to satellite and uplink beam contour.  

The modem output level must not be allowed to overdrive the BUC as that may damage the power amplifier transistors and cause interference to adjacent uplink carriers from other sites.

Using a short tx cable could overdrive and damage the BUC part of the TRIA.

Regarding choise of cable type note that the transmit cable has a much higher DC power current compared with an LNB and the DC resistance of the centre wire and sheath matter.  In particular steel cored, copper plated, centre conductors are not suitable.

As an illustrative example only, a BUC may be rated at 2 watts.  The nominal clear sky output for a 200kbit/s uplink may be set to 0.4 watts for 200kbit/s uplink and 0.2 watts for 100 kbit/s uplink.  Under rain conditions automatic uplink power control (AUPC) may be then allowed to increase the level by up to 6 dB or 4 times to 1.6 watts or 0.8 watts.  All this is configured and dynamically controlled from the hub to keep all inbound carriers working at equal quality into the hub.  Considering that the inbound links are TDMA it helps the hub receiver if all bursts in the sequence of bursts from different sites are of similar level and accurately on the same frequency.

I am interested in any feedback from TooWay users.  Please write here in this forum.  You are amongst the very few first users of this Ka band VSAT technology in Europe.  The same kit has been used for some time in the USA and Canada using the names Wildblue and Telesat.

Best regards, Eric.
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« Last Edit: Jul 21st, 2008 at 3:59pm by Admin1 »  
 
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Sean_Williams
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Reply #2 - Jul 24th, 2008 at 6:58pm  
Hello again
thanks for the valuable input Eric ;O)

I questioned BW about cable length and their view is that the system is tuned for 30m, but down to 25 is OK and even up to 60 would be OK, but not recommended.

We installed the first system today (it was HOT out there!) and after the usual messing about, turning things the wrong way etc, we found that once the azimuth was correct, we hooked up the MiniSat, gained a max of 3.5 on the meter and off it went.

Except we didn't know that, and spent a couple of hours searching for different satellites, better angles etc, but each time we came back to our original settings (which were spot on as it turned out).

The key here is that it takes an age for the modem to register, update and log-in.
We left everything connected while we had a break, wondering what to do next when after a few minutes we began to get activity.
In all, it took over 8 minutes to give a steady LED!

After that, software updates and activation consumed another 15 minutes.

Once it was active, the first couple of websites visited seemed to come up pretty quickly, but we quickly saw a marked deterioration in responsiveness, to the point that dial-up would have been quicker.

We have left the system on to let it do it's thing for a few hours, in the hope it improves after settling.

But on initial showing, I have to say I'm disappointed - the SkyDSL I also have is probably twice as fast, so to judge from Cambrian's postings, things are not yet as they should be as he says Tooway is a great improvement over SkyDSL - which is what I'm expecting.
As it stands, I'd rather have SkyDSL.

Am I right in supposing the Tooway system uses a proxy server somewhere? If so, anybody have any idea if it's known to be slow or anything?

Regards
Sean
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Eric Johnston
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Reply #3 - Jul 24th, 2008 at 7:12pm  
Thanks for telling us how it is going.  Tell BW about speeds; they won't know otherwise.  There must be some reason, as the network is new and there are few sites operational so the hub cannot be overloaded.   The hub is operated by Skylogic in Italy under contract from Eutelsat.

There are few Ka band satellites so I would be suprised if you found any other Ka band satellites at all round here.   

Did the readings on the polarisation scale (back of dish) work out OK ?

Best regards, Eric.
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« Last Edit: Jul 28th, 2008 at 4:55pm by Eric Johnston »  
 
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cambrian
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Reply #4 - Jul 24th, 2008 at 9:15pm  
Well done Sean, glad to hear you have got it going.

I just did speed tests on 2 sites and the download is ok 1.5M ish but the upload is rubbish tonight around 45Kb/s not much better than dial-up as you say. It is usually around 150-200Kb/S so all is not well with the Hub I suspect. 

With regard to the modem ranging and registering etc, it can be slow to react to changes as I said in my posts. That is why a meter is essential as I stressed, the Mini-sat doing the job nicely although others would work too I am sure. Waiting for LEDs to light is never going to be any use.

I use my system with a laptop and when it is not connected, I switch the modem of at the mains, often overnight. On switch-on in the mornings registration ie RX LED on steady can be only 40-50 secs. under clear skies, up to 10-12 mins. in heavy thundery cloud. Very variable.

I think you will find with the correct alignment, web surfing, email and downloading are very usable, I am certainly pleased with the performance of mine. I hope things are better tomorrow. 

Did you use my settings as a starting point?

Regards,

Tony
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cambrian
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Reply #5 - Jul 24th, 2008 at 10:11pm  
I have just noticed Eric's comment about setting up the next site with only the RX connected. I don't understand this and certainly would not want to disagree with an expert. But the TRIA needs 24 -30 volts to drive it, the MiniSat can't. The recommended method is to connect up the modem TX line to TRIA TX F connector and use that as the driver, just using the meter connected to the TRIA RX but NOT the modem because of the high DC voltage.
The WildBlue system has an optional separate 30v. power supply to drive the TRIA and uses a SuperBuddy meter for alignment if I understand it correctly.

I hope this makes sense and I have got it right, as I said, I don't want to pick a fight with an expert such as Eric!!!

I have just done another speed test (Think Broadband) and got 1504Kb/s down and 116.85Kb/s up, not as good as usual - perhaps having another TooWay close by is overloading the system! Only joking.

Regards,

Tony
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Eric Johnston
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Reply #6 - Jul 24th, 2008 at 10:39pm  
Tony, you are the one with experience of Tooway.  I am just learning from you and others.  

So to anyone setting up Tooway, read what Tony says above.   The method described will stop the modem receiving any signal at all from the LNB/TRIA and so should achieve the objective of preventl premature commissioning.

My experience with other types of VSAT is that it is not helpful to interrupt the operation, either by blocking the beam or cycling the power, once the receive and  transmit sides are connected and the unit comes under control from the hub computers and commissioning downloads are in progress.

Best regards, Eric.
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« Last Edit: Jul 28th, 2008 at 4:57pm by Eric Johnston »  
 
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Sean_Williams
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Reply #7 - Jul 25th, 2008 at 1:15pm  
Thanks for the feedback on speeds Cambrian.

Last evening, we were obtaining about 45kb/s down.
Then, we disconnected all the cables and reconnected them again.

This morning at 08:15 speeds were 1872kb/s down and 124 kb/s up, which is a satisfactory improvement in notional speeds, but the system is still very sluggish.

For instance, the Tooway system and another on ordinary lanadline broadband entered the bbc.co.uk URL at the same time; the broadband had loaded the page within 3 seconds whereas it took over 10 seconds for the Tooway system to begin downloading, which then took around 5 seconds.
This test was repeated over several URL's with similar results.

I feel this is unacceptable - again I can give the SkyDSL setup as an example: with a 40 kbs dial-up (so about 28 kbs uplink I guess), the lag between the start of download is only around a second or two, with full page withing 5 seconds. The download on the SkyDSL is a max of 1 mb/s but it actually runs at about 600 kb except for streaming.

So it would seem to me there is a real problem with the Skylogic hub being overworked.

Tony's upload speed of 45 kb last evening is what we were experiencing too - dial-up is better than this as by the time the Tooway system had responded and loaded the page, so would have dial-up.

We're currently discussing this with BW as we are feeling dissatisfied and are reluctant to activate the second system at the moment.

I should point out that James at BW is being helpful; in fact the people at BW have all been very friendly and helpful all along Smiley
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Sean_Williams
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Reply #8 - Jul 25th, 2008 at 5:50pm  
Regarding the connecting of the TRIA/Modem/MiniSat -

1.
Full length RX cable from TRIA to MiniSat only - nothing at all registered on the MiniSat

2.
Full length RX cable from TRIA to MiniSat only and Full length cable from Modem (switched on) TX to TRIA - no signal registered above background noise of 1.5

3. Short fly lead (supplied with MiniSat) from MiniSat to TRIAD RX and full length cable from Modem TX to TRIAD - base signal of 2.75, to max reading achieved of 3.6.

I would glean from this that the full length cable RX creates too much impedance to give accurate results when setting up and also that the TX cable is required to power the TRIAD.

Does that sound right?!

Cheers
Sean
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James-BW
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Reply #9 - Jul 28th, 2008 at 11:31am  
Hi all,

We are currently looking at overall performance of the system following tests on our colocated units. I will provide a full report as soon as I have recieved feedback from the teleport operators.

In a shared network environment, the system should perform to within the stated GOS document, Please contact BW if you do not have a copy of this, it outlines exactly what you should expect to recieve.

James - Bentley Walker Ltd
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El Molino Systems S.L.
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Reply #10 - Jul 28th, 2008 at 1:36pm  
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Eric Johnston
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Reply #11 - Jul 28th, 2008 at 2:24pm  
El Molino,

How does the customer get access to the information below ?

The Fair Information Policy (FIP) information given to subscriber.

Instantaneous real time information (Push)
    Network congestion (FAP active or not)
    FAPed or not
    Punished or not

Information on a web site (Pull)
   Account status
   Remaining Volume / Volume available
   FAP status

I see Skylogic describe some users as "Ab Users".  This term "Ab" is not defined in their list of abbreviations. Does it mean Abusive User, Abused User or Abnormal User perhaps ? Whatever, they need to come up with some expression that, in English, does not appear rude to the customers !

Best regards, Eric.
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James-BW
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Reply #12 - Jul 29th, 2008 at 11:12am  
Eric Johnston wrote on Jul 28th, 2008 at 2:24pm:
El Molino,

How does the customer get access to the information below ?

The Fair Information Policy (FIP) information given to subscriber.

Instantaneous real time information (Push)
    Network congestion (FAP active or not)
    FAPed or not
    Punished or not

Information on a web site (Pull)
   Account status
   Remaining Volume / Volume available
   FAP status

Best regards, Eric.


The information above will be provided to users at their request, currently the web interface is in its infancy and as such not suitable for average users, development is ongoing.

With regard to the GOS, ABusers are users whos traffic volumes exceed that of the GOS, this is not completely clear and we are reviewing the standard documentation offering.
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« Last Edit: Jul 29th, 2008 at 6:15pm by Admin1 »  
 
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Eric Johnston
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Reply #13 - Jul 29th, 2008 at 6:14pm  
I think it really does help to show customers what is their traffic useage and to provide feedback.  The HX traffic displays do this very well and allow customers to either modify their traffic demand or change to higher tariff with greater allowance.  The HX displays are a major selling point - it shows you are honest and up front about traffic use and the system truly fair.  

So I wish Skylogic / Bentley Walker well with the development of a Tooway web interface showing network status and traffic stats.

I suggest the term "Agos user" to describing users whose traffic is "Above their GOS".  This sounds polite to me.  To other people europe a question:  Does describing someone as Agos seem rude to you in your language ?  If you are happy with this, I suggest Skylogic change the abbreviation "Ab user" in their GOS documentation to "Agos user".  Other ideas welcome.

Best regards, Eric.
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« Last Edit: Jul 29th, 2008 at 7:43pm by Eric Johnston »  
 
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