Topic 'Low CCQ. Reasons and any suggested fixes for customer' in forum 'Wireless Networking' - dslreports.com

Re: Low CCQ. Reasons and any suggested fixes for customer

Mon, 31 Dec 2012 08:56:04 EDT

Semaphore posted : 4 db SNR is FAR to low to be stable on 900Mhz. Without knowing the specs on the hardware it's hard to say why it's so low.

Also the 900Mhz Fresnel is very large. I doubt that you are on the very edge of the hill, but more likely your are back a hundred feet or more. It's not uncommon in a setup such as that to get a bounce from the face of the hill that is giving you the elevation, which could cause the symptoms you see.

There is radio modelling software that can calculate this for you. The learning curve is VERY Steep but Radiomobile is one of the best. A Fresnel refraction, AKA a 'Bad bounce', would explain the ridiculous distance measurement too. Lack of TX CCQ is almost as destructive as lack of RX CCQ.

Re: Low CCQ. Reasons and any suggested fixes for customer

Wed, 19 Dec 2012 14:32:45 EDT

Lighthope posted : I am at 2200 feet elevation. The valleys will dip about 300-500 feet. There are no hills between me and the tower.

Re: Low CCQ. Reasons and any suggested fixes for customer

Wed, 19 Dec 2012 14:24:16 EDT

HELLFIRE posted : Just how bad are these "mountains, hills and valleys?" Barring a detailed analysis by a certified radio expert,
and some further testing, this is my best guess likely what is happening Lighthope

Regards

Re: Low CCQ. Reasons and any suggested fixes for customer

Tue, 18 Dec 2012 18:02:02 EDT

Lighthope posted : So you don't think this is caused by any man-made interference but rather naturally occurring interference from radio waves bouncing all over the place? I live in the mountains. While there are no obstructions between myself and the tower, the terrain does vary with hills and valleys.

Re: Low CCQ. Reasons and any suggested fixes for customer

Tue, 18 Dec 2012 16:08:37 EDT

LLigetfa posted : I think that fresnel zone calculator makes the assumption that both towers are the same elevation and that the world is flat.

The taller the WISP's tower, the less height you need at the sub. One can also get into destructive fresnel zones and reflections so trial and error is your friend.
--
Strange as it seems, no amount of learning can cure stupidity, and formal education positively fortifies it. -- Stephen Vizinczey

Re: Low CCQ. Reasons and any suggested fixes for customer

Tue, 18 Dec 2012 13:32:58 EDT

HELLFIRE posted : Try this URL : »www.wirelessconnections.net/calc···Zone.asp

If I recall my radio physics right, 1/2 way between you and the tower needs to be at least 124ft of no physical
obstacles / clearance for the Fresnel zone, while the 60% zone (best-possible-conditions, IIRC) is 98ft.

** BTW, I'm REALLY rusty on radio physics, so if I'm misinterpretting the results, feel free to correct me but don't
call me stupid ;)

I'd follow LLigetfa's suggestion and see if you can't get some more height in; HOW much more REALLY needs to
go to a radio / wireless expert as I am WELL and TRULY out of my depth now.

Regards

Re: Low CCQ. Reasons and any suggested fixes for customer

Tue, 18 Dec 2012 01:17:41 EDT

Lighthope posted : Any suggestion as to a height? We're not talking hundreds of feet are we?

Re: Low CCQ. Reasons and any suggested fixes for customer

Mon, 17 Dec 2012 16:23:51 EDT

LLigetfa posted :

said by Lighthope:

I have LOS to tower...

Height of antenna on my end is about 15 feet.

You need better than line of sight. You also need a clear fresnel zone. A 900MHz signal requires a larger fresnel zone than a higher frequency. You may want to try a higher elevation.
--
Strange as it seems, no amount of learning can cure stupidity, and formal education positively fortifies it. -- Stephen Vizinczey

Re: Low CCQ. Reasons and any suggested fixes for customer

Mon, 17 Dec 2012 13:53:00 EDT

Lighthope posted : I have LOS to tower. Nothing is in the way. Tower is omnidiretional; my radio is directional.

Height of antenna on my end is about 15 feet.

Re: Low CCQ. Reasons and any suggested fixes for customer

Mon, 17 Dec 2012 13:37:33 EDT

John Galt posted : What height is the antenna on your end?

Re: Low CCQ. Reasons and any suggested fixes for customer

Mon, 17 Dec 2012 11:44:35 EDT

HELLFIRE posted : Short answer, I don't think there's any easy fixes for your problem. Maybe someone else more versed in
radio theory can explain better, but some basic stuff off the top of my head :

- 7 miles to tower : this line of sight? Do you know if the antennas being used are directional or omnidirectional?
- transmitting on the 2Ghz frequency : rule of thumb for radio waves is the higher the frequency, the shorter
the distance they can transmit. Also, higher frequencies are more sensitive to interference from things like solid
objects and water vapor -- guess why microwave ovens are so good at heating up water?

Based on your info so far, its not a technical issue but just an issue of plain old radio physics.

Regards

Low CCQ. Reasons and any suggested fixes for customer

Mon, 17 Dec 2012 00:21:48 EDT

Lighthope posted : I don't know if you can help, but I would appreciate any advice and assistance.

I am a customer of a wireless broadband company in rural Eastern Washington. This company got a federal grant to build up wireless internet for us poor rural people who have to suffer with satillite internet. (Ugh)

Sadly, the network they built up is actually worse than satellite. (Your tax dollars at work) Speeds are variable, the CCQ is in the basement most of the time. Large uploads are impossible as the connection times out.

Interstingly, this is not something that is constant. It is variable throughout the day, but can be worse in the morining, sometimes acceptable in the afternoon, and almost completely unusuable in the evening.

I am told that this problem occurs thoughout the county, so this isn't a spot problem. However, it is important for me to point out that I personally am 7 miles to the tower. They were actually surprised I could get a connection. But when it works, it works great. At first there was no trouble, but as the months passed, everything degraded until we are at this point now.

At first they said it was a pirate signal, but now they say it could be an air traffic control signal from Canada. Truthfully, they don't know, and I have no knowledge of them hiring someone to try and find the source of interference.

So, the crux of my problem:

They really don't respond to service calls or e-mails. So dealing with them is not an option. They are a monopoly, so what can I do?

Is there anything I can do on my end to alleviate some of the problem?

System transmits on unlicened 900 mHz using Mikrotec antenna. (I think that is what it is.)

Currently transmitting on Band 2GHz-10MHz, Frequency 2442 MHz
Wireless Protocol 802.11 Channel 0. Channel Width 10 mHz. Transmitting and receiving at 6 Mbs using 18BMm power. (Changing power yeilds no results)

Noise Floor -90 dBm
Signal To Noise 4 dB
Tx/Rx CCQ 26/80 %
Overall Tx CCQ 26 %
Distance 92 km

Distance is wrong. It's report varies from 17K to 120K

Rx CCQ will dip to 50%.

Any thoughts on what can be causing this or what I can do on my end to correct this.

Mind you, the company said they are getting another 20 million to upgrade their system to a licnenced band with better equipment. In theory it should correct the problem. But they have been promising this for years, hence why I have given up on waiting.