True Non Line of Sight Frequency !!

indianboy · Thu May 17, 2007 9:08 pm

Anyone please let me know if there exists a true non line of sight frequency apart from 900 Mhz in 802.11 .

If yes then which is the frequency and which wireless card supports it .

Also does Mikrotik will support the same ?

indianboy · Fri May 18, 2007 7:41 am

No one ???

janisk · Fri May 18, 2007 10:43 am

there is no such thing like NLOS frequency, as it highly depends on what is your obstacle. will it absorb or reflect the signal.

indianboy · Fri May 18, 2007 2:04 pm

there is no such thing like NLOS frequency, as it highly depends on what is your obstacle. will it absorb or reflect the signal.

The obstracles are mainly trees ( absorbing element ) and iron/steel ( reflecting element )

The setup need to be with a radius of 5 kms NLOS in indoor with walls, concrete blocks and all sort of industrial problem.

But i can't use 900 Mhz.

Any idea how ???

cmit · Fri May 18, 2007 4:40 pm

Ouch.

If you really want to cover an area with 5 km radius, want to connect the clients even indoors and have "industrial" environment (concrete, steel, metal, ...), then you will have a hard time. You'll probably have to install a bit more than one AP to cover that range, and even then the "indoor" connectivity could be quite hard to achieve...

You actually would have to tell more to get a more precise answer, I think...

Best regards,
Christian Meis

Ghassan · Fri May 18, 2007 5:11 pm

well , you can not

do this .. I already tried and I have faced a billion of problems .. but It was my idea from the beginning ..

few meters can achieve a little .

Ghassan · Fri May 18, 2007 5:14 pm

Are you talking for a NLOS

with radius ..

if your clients has a low power then you can not because I already tried , right christian ?

cmit · Fri May 18, 2007 5:29 pm

What I tried to say was that I think you'll at least run into a bunch of problems trying to do what the original poster asked for.
Of course it CAN be done, but then you'd probably have to install a ridiculous high number of APs across the area, which will most probably make it too exensive/complex.

Best regards,
Christian Meis

Ghassan · Fri May 18, 2007 5:36 pm

What I tried to say was that I think you'll at least run into a bunch of problems trying to do what the original poster asked for.
Of course it CAN be done, but then you'd probably have to install a ridiculous high number of APs across the area, which will most probably make it too exensive/complex.

Best regards,
Christian Meis

are you sure you can run it on None Line of sight because I am interested in None Line Of Sight .

I am not searching for NLOF to make it complex .

tgrand · Fri May 18, 2007 6:02 pm

The lower the frequency, the better the NLOS performance, and the best wave propagation.

AM/FM Radio is real good, but still not perfect.

indianboy · Fri May 18, 2007 6:12 pm

Ouch.

If you really want to cover an area with 5 km radius, want to connect the clients even indoors and have "industrial" environment (concrete, steel, metal, ...), then you will have a hard time. You'll probably have to install a bit more than one AP to cover that range, and even then the "indoor" connectivity could be quite hard to achieve...

You actually would have to tell more to get a more precise answer, I think...

Best regards,
Christian Meis

1. My Client will use regular Lan Card ( At most i can give them CM9 with a mini-PCI to PCI Adaptor with a 3 dbi Omni antenna ) or else a 500mW Client Adaptor with 3 dbi Antenna ( 1W output to warm up the hotdogs.. )

2. The challenge is to cover a shed which is 3 km long.

3. Contains all sorts of Industrial overhear cranes which always keep moving.

4. The cranes keep on dumping the metals anywhere they like.

5. The Plant is a Steel Plant.

6. I can go with multiple AP to cover the whole area.

7. Cost is not the issue as this is a challenge by one of my competitor who claims that wireless networking is not possible at that place.

8. I am planning to use 20 Mhz because i think the CM9 in Windows can't detect 5,10 Mhz.

9. I think 802.11g will be a good option because of the OFDM modulation which can detect multi path signals.

Anyone willing to share something will be real nice ...

Ghassan · Fri May 18, 2007 6:12 pm

can you give us any wireless card that can lower my frequecny and what is the best frequency that can make my None Line OF Sight to be better ... because I can build any sector with my own frequency , my latest sector that i had , it was 2.7 ghz but I am searching for a good wireless card that can transmit 2.7 ghz ..

Thank you

Ghassan

indianboy · Fri May 18, 2007 6:23 pm

can you give us any wireless card that can lower my frequecny and what is the best frequency that can make my None Line OF Sight to be better ... because I can build any sector with my own frequency , my latest sector that i had , it was 2.7 ghz but I am searching for a good wireless card that can transmit 2.7 ghz ..

Thank you

Ghassan

2.7Ghz card is not available right now but such a card is planned by Ubiquiti which will support 2.7~2.9Ghz.

BTW : You made your own antenna ???

tgrand · Fri May 18, 2007 6:39 pm

In the stated environment I would suggest that higher frequencies are better.
You are dealing most with reflection.

Use Lower power with higher number of APs for coverage.
Use a radio with as poor a receive sensitivity as possible.
The Higher frequencies will attenuate quicker than low frequencies, so the reflections will be much more attenuated using higher freqs than with using lower freqs.

Ghassan · Fri May 18, 2007 6:41 pm

yes I made my antenna finally but If I can not use 2.7 ghz right now I can change my calculation of doing antennas so I can make it lower than 2.4 ghz so If I can use the 900 Mhz at WIFI it would be great for mine to do the antenna but I think it will take time to think of doing antennas .

can you give me such Mikrotik Wireless Cards so I can buy it right away .

Ghassan · Fri May 18, 2007 6:47 pm

In the stated environment I would suggest that higher frequencies are better.
You are dealing most with reflection.

Use Lower power with higher number of APs for coverage.
Use a radio with as poor a receive sensitivity as possible.
The Higher frequencies will attenuate quicker than low frequencies, so the reflections will be much more attenuated using higher freqs than with using lower freqs.

yes I am dealing with reflection .

400mw is enough for me because I have about more than 30 access points and I am afraid of problems if I had more than 40 access points so what should I use routerboards and cards ..

so if i want to use for example 2.6 ghz is it better than 900 Mhz . and if it is better then give me a link to buy the card or a name for a card or router board that can handle more than 100 customers at a time .

indianboy · Fri May 18, 2007 10:02 pm

In the stated environment I would suggest that higher frequencies are better.
You are dealing most with reflection.

Use Lower power with higher number of APs for coverage.
Use a radio with as poor a receive sensitivity as possible.
The Higher frequencies will attenuate quicker than low frequencies, so the reflections will be much more attenuated using higher freqs than with using lower freqs.
yes I am dealing with reflection .

400mw is enough for me because I have about more than 30 access points and I am afraid of problems if I had more than 40 access points so what should I use routerboards and cards ..

so if i want to use for example 2.6 ghz is it better than 900 Mhz . and if it is better then give me a link to buy the card or a name for a card or router board that can handle more than 100 customers at a time .

Let's Keep both our problems seperate because there is a lot of confusion with the answers.

I don't know whether those are for me or you.

High Frequency - High Attenaution - That seems convincing.

But what is the trick behind using a low sensitivity radio ? Do you want to suggest that a low sensitive card will not hear the reflected highly attenuated signals ? Only the unreflected signals will have enough power to get to the repeater/wds AP .

Wow... that a brilliant thought.

BTW : Only 10-15 Pc's will be on the planned netwok.

tgrand · Sat May 19, 2007 3:48 am

Only 15 PCs...

My suggestion may not be worth the Radio count costs.
But yes, a lower sesitivity radio will be less affected by the reflections.
Keep in mind that my proposition also calls for more radios to be used.

Ghassan · Sat May 19, 2007 10:39 am

The antenna is a centre-fed broadside array antenna, based on the Franklin Antenna

This antenna is suitable for use in Computer Radio LANs conforming to the IEEE 802.11b/g standard – better known as Wifi. It can be used on an Access Point (or wireless Router) or Wifi client with equal benefits.

This is the best antenna I ever had . so what do you mean by less sesitivity will be less affected by the reflection .

tgrand · Sat May 19, 2007 6:54 pm

My recommendation was for IndianBoy in an industrial environment, with lots of steel. In an urban lanscape there is little you can do for buildings and such. In this scenario you are best to plan the layout of the sectors to minimize reflective influences to the AP. The clients are a different problem entirely.

P.S. Great job on those antennas..
Is the a place I can go to get more information on this design?

indianboy · Sat May 19, 2007 7:26 pm

My recommendation was for IndianBoy in an industrial environment, with lots of steel. In an urban lanscape there is little you can do for buildings and such. In this scenario you are best to plan the layout of the sectors to minimize reflective influences to the AP. The clients are a different problem entirely.

P.S. Great job on those antennas..
Is the a place I can go to get more information on this design?

Here You Go tgrand

Centre-Fed Broadside Array Antenna

http://pe2er.nl/wifisector/

npero · Sat May 19, 2007 8:11 pm

Orginal desing by Dragoslav Dobričić, YU1AW. Here is site

http://www.qsl.net/yu1aw/vhf_ant.htm
or 
http://yu1aw.ba-karlsruhe.de/ANT.htm
or
http://www.qsl.net/yu1aw/ANT.htm

2.4GHz, 5.8Ghz sector and directional antena very easy to bulid.

I also try to build some of them and work very well.

Best regards....

Ghassan · Sat May 19, 2007 11:34 pm

I am using the AMOS 9

and for this calculation to change to 2.7 ghz all i have to do is calculating it to new :

You can make scaling of almost any antenna if you multiply all
dimensions of antenna by scaling factor. Scaling factor is ratio of
design and new frequency. For instance: k=2450/2700=0.9074

So, NEW dimensions will be NEW=OLD*k

well , finally I wanna ask you for a good frequency far than 2.3 or 2.4 ghz so if anyone can give me a card so I can use it to make my own frequency .

another question , where can I find Routerboard that can handle 2 wireless cards 400 mW or 600 mW or more slots?

Thanks to Dragoslav Dobricic .

Ghassan

nickb · Tue May 22, 2007 7:57 am

Honestly it sounds like a perfect application of 802.11-n draft stuff. 802.11n is designed, intended, and works best in a highly reflective environment - which is exactly what you've described.

It's also my understanding that at the MUM coming up there should be some announcements about 802.11n ....

indianboy · Tue May 22, 2007 10:15 am

Honestly it sounds like a perfect application of 802.11-n draft stuff. 802.11n is designed, intended, and works best in a highly reflective environment - which is exactly what you've described.

It's also my understanding that at the MUM coming up there should be some announcements about 802.11n ....

How many n-Draft AP can solve my problem in the mentioned scenerio ?

True Non Line of Sight Frequency !!

True Non Line of Sight Frequency !!

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