Satellite Internet Forum

[liljim]

Hi, I am in north Louisiana and unfortunately stuck with Starband. I have a Skyedge IP vsat modem and I am suppose to be getting 500 or so down and 100 up. I've only had this system since January 07 and its been problematic from day one. Tech support doesn't like talking to me anymore, apparently they don't like being criticized for not knowing whats going on with my connection. Here is the deal, over the last 2 weeks my connection has been getting slower and slower. 3 days ago I ran a bandwidth test on speedtest.net and hit 16kbps down and 22kbps up. You can imagine how upsetting this can be when your paying 50 bucks a month for 500 down. Just for self assurance, I ran the test 4-5 times, each to a different server which generated close to the same results. It was to late in the day to contact tech support so I surrendered for the night. The following day i was running around 200-220 down and 60-70 up which is also what I am getting today. So far I haven't been able to get starband on the phone nor a response from email. I should also add this is with clear weather.

My system is clean, my PC knowledge is extensive, I build, repair, upgrade, clean, etc. My knowledge of satellite internet simply sucks. I am behind a router with 2 other machines on the network however they were unpluged during the bandwidth test. My EbNO runs 6-6.5.

I doubt that it matters but i have access to the installer side of my modem, modulation and coding setting etc. but don't know if there is a benefit to it.

Is there anything i can do to at least get up to where I should be? Are there any adjustments that can be made on my end that would help?

here is a test result from 4/24

speed-test-1.jpg (14.03 KiB) Viewed 103 times

here is one I have just ran

speed-test-2.jpg (14 KiB) Viewed 104 times

I don't have anything running in the background. Do you guys have any ideas at all?

[Mike Veit]

-Does throughput (speed) improve by power cycling the modem, then decrease slowly over time?
-What speeds results are obtained during off-peak hours (0100-0500 local)?
-What kind of packet loss are you experiencing (a) when your speeds are close to acceptable, and (b) when they are down in the dumps?
-Eb/No sounds low, but I don't know your hardware. Do you have a means by which to determine transmitter isolation? How much rain does it take to make your connection drop out?

I strongly recommend selecting one speed test site and sticking with it. When troubleshooting satellite connections, who gives you the fastest speed results is not the objective. It's all about the space segment. Find out where your gateway satellite terminal is physically located. Ideally, your provider should provide a customer-only speed test server. The idea is to test the space segment; that is, from you to the distant gateway and back. Short of that, the speed test site you select should be as geographically close as possible to the gateway to minimize terrestrial influences. Once you get a feel for the speed patterns between you and the gateway, THEN move out into the internet for further samples. Just WHERE the slowdowns are occurring will then become easier to track down.

[liljim]

Thank you for your reply.

Rebooting the modem has no effect.
Off peak hours has been hitting 250-300 down.
Starband tech tells me my ebNO is normal, they checked my alignment and called it good. To me, it looks as though the signal could be better but I don't know. Heres a screenshot from my modem:

VSAT Modem RX ebNO

vsat-modem-rx-ebno-display.jpg (4.76 KiB) Viewed 98 times

A means to determine transmitter isolation is beyond me. I'm not real sure what exactly that is, my apologies.

A light rain will knock me offline pretty quick, usually I have to go out and wipe off the horn to get back on after a rain.

Starbands equipment is in Atlanta Georgia so that's where I'm running my speed test to.

[Mike Veit]

On the surface, it sounds like an antenna pointing issue. The fact that it's getting worse with time could suggest that the installer also neglected to tighten down the alignment nuts/bolts. If it's a pole mount, the pole could be turning in the ground. What is Starband policy about remedying substandard installations?

[liljim]

Their policy is the installer is responsible for 3 months, after that your on your own. None the less, their trying to convince me that i have a good signal anyway. I can also tell you when my signal drops below 5, my actual internet speeds are worse than dial up. I dont see how 6 could be good if 4.9 is pretty much useless.

[Mike Veit]

I think we agree that you need your dish pointing angles optimized. The SB folks who gave you that "if it works, there's nothing wrong with it" quite probably have marching orders to take all means necessary to avoid sending out an installer at Starband expense.

Assuming your 3 months are up, bit the bullet and call an installer. Pay what it takes to fix what I think we both believe is a pointing angle issue.

[DFowler]

Check all is tight, then repeat the Eb/No measurement several times.

With a low receive quality Eb/No =5.96 dB I would start with 1/2 a turn up on the elevation nut and look for any change. If an improvement, keep going, otherwise try the other way. Then optimize azimuth.

[liljim]

Thank you both for your advise. I was browsing around through Starband's site last night and stumbled upon their training pages. I found all the installer documentation for the nova modems and the phase III dish that I have. This included information on how to adjust elevation and azimuth. I also found the point dish software that determines the alignment parameters by zipcode and the satellite your shooting to which is 72 west in my case. I haven't made any adjustments yet but I will be doing so this afternoon. I will post the outcome.

Thanks again,
Jim

[Mike Veit]

Pay particular attention to anything mentioned about transmitter isolation. Eb/No is important, but it's a function of your receive. You can achieve good Eb/No, but still have bad transmitter isolation. Once the best Eb/No is obtained, you must then move on to optimizing the transmitter isolation. It's counter-intuitive, but it's then normal to peak transmitter isolation at the expense of some Eb/No.

That is the specific reason that I first mentioned obtaining the services of a Starband installer.

[liljim]

Thank you, i'll see what i can find about it.
 
This is what i've done so far, my signal was running 4.80 ish' when i started playing with the adjustments. I had my loving wife watch my screen while i adjusted the dish, communicating through cell phones. My dish is pole mounted by the way. I began to raise the elevation until i loss signal, noting the strongest point then lowered until losing signal. My strongest point in that direction yielded a 5.10 from the previous 4.80 so i locked it down there. At that point, i loosened the pole mounting bracked which allowed me to slightly rotate the dish either way. The best i could get there was 5.90, locked it there also. At this very moment, theres a slight overcast and its 8:25 pm and im getting a 6.8.  
 
Heres where it gets odd, and it may be what your talking about with transmitter isolation. I ran a bandwidth test just now and pulled 573kb down and 40 up. Once that completed, i re-ran it to get 168 down and 40 up. The next one was 92 down and 24 up.  
 
I dont know if theres a relevance or not but during the test it appears to "hang". This has been the case ever since my bandwidth issue started. The 573 test ran without hangs. All of these test were done at speedtest.net using the Atlanta Georgia server. I jumped over to speakeasy.net just for the hell of it and i get the same hangs and slow speeds, these test go to Houston Texas. To clarify a statement made previously, im not looking for the site that gives the fastest result. Its just a personal comparison.  
 
I think if this continues, im gonna just go out and set the dish just off enough to lose signal and raise hell with starband until they have no choice but to send someone out with the right tools for the job.

[liljim]

I might be able to explain "hang" a little better.

It will start downloading/measuring, pause for a sec, resume, pause and so on. It does this on both down and up test. I hope that makes a little sense.

[Mike Veit]

I don't see where you tried to do anything with the polarization angle.

[liljim]

i did not mess with it.

[Mike Veit]

Hmmm, well. The POL angle is what actually provides the basis for meaningful transmitter isolation. If your problem was a transmitter issue in the first place, then all you've done with the AZ and EL is sorta tread water. Again, it's typically an installer function - since they have access to the resources to optimize transmitter isolation. You and I as subscribers (at least subscribers without special equipment or support numbers) don't have that luxury.

[Saberis]

I don't see any mention of your skew angle (otherwise referred to as POL or tilt angle). Skew angle can affect your Transmit / Receive signals. I have set up the dishes consistently with signal quality of 9.0 and higher.

The figure below shows an example only. This system is set to receive nominally horizontal polarization with a minus 13 deg anticlockwise adjustment applied. The satellite is a little to the left of due south (for northern hemisphere locations). The polarization starting position (before the adjustment is applied) is with the broad faces of the LNB waveguide and filter exactly on either side - this is true receive horizontal polarization.

horizontal-polarization.jpg (21.11 KiB) Viewed 99 times

Find your polarization adjustment angle here: satellite TV dish pointing USA. A good way to set it is to put an inclinometer sideways across the BUC, LNB body, LNB waveguide narrow edge etc. You may even be able to read a tiny scale on the feed throat. Note that adjustments are made while facing the satellite.

Always start by setting either horizontal or vertical, as instructed by the hub for your downlink signal. Vertical is with the broad faces of the LNB waveguide on the top and underneath.