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New tower

Posted: Fri Sep 14, 2012 2:24 pm
by lorenzesz
Hi,

i am planning a tower, with a 100 mbit fiber connection that already is purchased. Reading the forum makes me confused. Many people report 200 mbit real throughput in ptp, others have per sector 50 mbit in ptmp and a lot of problems with nv2.

I want to use instead of large sectors on the tower, a lot of sxt devices in a ptmp setup. The cpe's will be also sxt but with mounted dishes.

Here some data:
Rural environment
Tower1: 25 m on hill 600 m
(maybe also my roof, but later)
Distance to clients: 100 m - 4 km, hight 500 - 550 m
Gateway Pipe: 100 mbit
Desired bandwidth per client: 50 mbit aggregate with LAN enabled
CPE: SXT with dish
Base station: Many SXT's with max 4 clients per device

The reason why i want that bandwidth is because i want to sell traffic in gb to the customers. LAN also enabled.

The questions:
I will have at least 10 SXT's on the tower. What kind of rf shield is cheapest?
What channel width to choose?
How many mhz between channels for separation?
How many cm distance between SXT's on the tower for separation?

It will be cheapest to buy 3 or 4 Sixpacks, so i can use the Omnitik to extend the network. But i need to upgrade the license level to 4 for the SXT's (on the tower) when the network grows and if i need to connect more than one CPE per SXT (on the tower).
What are the costs for upgrade?
Can i buy volume licenses?

And last: What is the status of NV2 development? Will the 6.x. release fix all the problems that ppl have?

Lorenz

Re: New tower

Posted: Fri Sep 14, 2012 5:58 pm
by lorenzesz
No one?

If i have 9 not interfering channels in the 5 ghz outdoor band, is it theoretical or are they really not interfering? Is there something like channel bleeding?

Re: New tower

Posted: Fri Sep 14, 2012 6:10 pm
by lorenzesz
I found a channel reuse pattern: http://setup-wireless.blogspot.com/2008 ... rence.html

What distance do you suggest between the sxt's on the tower and what kind of rf shields? Will help slant polarization on every second sxt for limiting interference?

Re: New tower

Posted: Fri Sep 14, 2012 6:29 pm
by mahnet
Why SXT's on the TOWER. They are CPE's for the client end. You can have better things with better results. 711-5HnD with a panel antenna and a metal shield enclosure. or R52Hn with a RB800 or RB 433AH. both are MIMO and capable enough to give 50 mbps per client as per ur desired 4 client per AP.
Also you don't' have SXT with AP license and the plastic covers cause lot of interference. Using Reflectors will consume lot of tower space as well.

Give Karma, when my posts help you.
Mahnet

Re: New tower

Posted: Fri Sep 14, 2012 11:10 pm
by lorenzesz
Why SXT's on the TOWER. They are CPE's for the client end. You can have better things with better results.
They are cheap and SXT G-5HnD has a level 4 license.
711-5HnD with a panel antenna and a metal shield enclosure. or R52Hn with a RB800 or RB 433AH. both are MIMO and capable enough to give 50 mbps per client as per ur desired 4 client per AP.
But twice as expensive per AP.
Also you don't' have SXT with AP license and the plastic covers cause lot of interference.
I would make my own metal cases.
Using Reflectors will consume lot of tower space as well.
The reflectors are on client side.

Right now i am tending to sextants in own made metal cases because of the narrower beamwidth, so i can use less transmit-power for each.
And i lower the bandwith to 25 mbps and 5 mhz channels. (Hope that this will work)
When using 5 mhz channels and seperate them 5 mhz i could put on the tower 20+ Sextants as AP. More than enough.

Will this work?

Re: New tower

Posted: Fri Sep 14, 2012 11:47 pm
by karina
A very ambitious idea indeed, however, I think you will have many problems with so many radios. The Sextant is not really a carrier class device. hence the budget price. Lots of cable, power supplies, many reasons not to do this. Have you done a spectrum analysis of the area? How many channels are available for you to use? Even if the whole spectrum was clear now it wont always be, I would suggest you went for something like a 433 board with 3 radios and 120 degree sector antennas. By using one of the Mikrotik TDMA protocols you should be able to match 20 sextants. I think the cost would work out fairly similar with the end result being a quality low maintenance installation that should give you years of service.

Re: New tower

Posted: Sat Sep 15, 2012 10:24 am
by mahnet
A very ambitious idea indeed, however, I think you will have many problems with so many radios. The Sextant is not really a carrier class device. hence the budget price. Lots of cable, power supplies, many reasons not to do this. Have you done a spectrum analysis of the area? How many channels are available for you to use? Even if the whole spectrum was clear now it wont always be, I would suggest you went for something like a 433 board with 3 radios and 120 degree sector antennas. By using one of the Mikrotik TDMA protocols you should be able to match 20 sextants. I think the cost would work out fairly similar with the end result being a quality low maintenance installation that should give you years of service.
By TDMA protocol do you mean Nstreme or Nv2. He needs 50mbps per client, i.e. too much of task for the 433AH with 3 cards in it and sector antenna. Lot of interference amongst the cards.
And a good PCI card with heatsink won't fit 3 numbers in one 433 board. We are using one R52Hn per 433ah and getting decent results.

Re: New tower

Posted: Sat Sep 15, 2012 11:41 am
by InoX
What is "LAN also enabled"? Why someone would disable lan?

Re: New tower

Posted: Sat Sep 15, 2012 12:10 pm
by lorenzesz
What is "LAN also enabled"? Why someone would disable lan?
LAN means that the clients are not isolated.
The Sextant is not really a carrier class device. hence the budget price. Lots of cable, power supplies, many reasons not to do this.
It should handle 4 clients. Cables yes. But i switch them into one 1 GB Ethernet to the proxy. I am afraid of interferences between the channels and the radios.

I have the whole spectrum free right now at the tower. But in the town are three or four 5GHZ radios.

I was thinking about really good cards with 3x3 and beamforming. But after reading the forums i see that with such setup i could not offer 25 mbits to the clients. Never ever.

Of course my clients will pay per Gbyte traffic, so there should be not more than 3 mbit per client per month average. But to be competitive i need those fast connections not only on paper, but in real conditions. And i think using smaller cheaper AP is the only solution to offer that bandwidth.

Your suggestions are really welcome.

Re: New tower

Posted: Sat Sep 15, 2012 2:40 pm
by lorenzesz

Re: New tower

Posted: Sat Sep 15, 2012 7:06 pm
by n21roadie
I have used their products and would recommend them but remember the shielding paint when dry can flake off or particles can be dislodged when the antenna is vibrating in high winds and they could lodge on the routerboard pcb and being conductive ?????
I had to apply a sealer over the conductive paint at hand i used clear varnish. I would not use SXT for a AP and my use of them was to have them attached to a dish for a PTP link.
http://forum.mikrotik.com/viewtopic.php ... th#p284475

http://forum.mikrotik.com/viewtopic.php ... 80#p316998

Re: New tower

Posted: Sat Sep 15, 2012 9:15 pm
by samsung172
sxt will drastic reduse output power, if you move from about 5550. Its really bad antenna to use just 150mhz from its "center".

Re: New tower

Posted: Sun Sep 16, 2012 1:00 pm
by lorenzesz
sxt will drastic reduse output power, if you move from about 5550. Its really bad antenna to use just 150mhz from its "center".
I understand. In that case i think i will use them only for farther clients as cpe's mounted on dishes using the 80 mhz from 5.47 - 5.550 ghz.

As AP's i found this:
http://www.cyberbajt.pl/produkt/4861/cy ... -mimo.html

They are already in metal cases and have the same price as sextant. Using ten of them gives me 180 degrees of range and i guess i can order already with level 4 license. But: 2000 g and 390 x 430 mm per unit. 20 kg and 4 meters all together... :(

Re: New tower

Posted: Sun Sep 16, 2012 1:29 pm
by n21roadie
sxt will drastic reduse output power, if you move from about 5550. Its really bad antenna to use just 150mhz from its "center".
I understand. In that case i think i will use them only for farther clients as cpe's mounted on dishes using the 80 mhz from 5.47 - 5.550 ghz.

As AP's i found this:
http://www.cyberbajt.pl/produkt/4861/cy ... -mimo.html

They are already in metal cases and have the same price as sextant. Using ten of them gives me 180 degrees of range and i guess i can order already with level 4 license. But: 2000 g and 390 x 430 mm per unit. 20 kg and 4 meters all together... :(
You may want to or plan to use 5.47 - 5.550 ghz. but I have found it is better planning to use antenna's that have 4.9 to 6Ghz bandwidth for many reasons and gives a lot of options,

The antenna you list may have a metal enclosure for the board + radio card but does the attached antenna section have RF screening all around the sides when it's beamwidth is 18° H+V