Hello everyone,

you might have guessed from the subject what the question is .... is there any way to provide wireless broadband solution in a city type scenario (Non-line of site of course) say in 4-city blocks on Mikrotik.

What is OFDM really?? and is it Non or Near LOS ??

Can anyone send me some config of the same I am novice in this ...

The best way to get NLOS is to use 5mhz bandwidth channels. But then the customers need to have CPEs like the Router Boards with ROS on them or LiteStation2 which now does 5mhz. I think there are a small handfull of units that can do it but it's the best thing I think of.
If your customers are going to be using standerd wifi cards then you are going to need to use a SR2 and a 15dbi omni if you are trying to cover this area with one AP.
Hear I am telling you all this and I have no idea what your 4 blocks looks like. Are the buildings tall or are there buildings at all, maybe just houses.

Anyway, if you don't have any equipment at all, I would start with the RB532 , SR2, 48V POE, Outdoor case, N type bulkhead pigtell, 15dbi omni.
With this you will get a good idea for what you will need to add.

How much improvement in margin (db) will a 5 mHz channel provide over using 802.11b - say with for example SR2 cards?

What throughput will one get using 5 mHz channels?

Approximately 6dB improvement over 20MHz channels, but the real life improvement is better because you will do a better job punching through interference.

We limit air rate to 24Mb to get max power output with minumum variation, and expect the customer to get around 3Mb data rate.

George

Jober: What I can do is send out Lat & Long to you for the site and you can see on google earth and then help out a little,.,,, is it possible???

Sure! give it to me.

please note the co-ordinates
N28deg 32.926'
E77deg15.110'

regards

How tall are the building I'm looking at?
Are you trying to cover all of them?
Will you be providing internet service to people with laptops in these buildings?
Will this be a roof to roof network?
What are the buildings made of? Concrete,brick,lots of windows)
How much of this area are you trying to cover?

this is just for example... buildings are about 9 storeys high some are 16 stories... ALL made of concrete and bricks ....lots of windows on each of the four side there are about 10offices on each floor about 900sqft.

IF POSSIBLE THE WHOLE AREA..
2.4 here is conjysted is like trying to walk with a bear trap on your leg.

If you have access to the roof tops you could setup a 5.3Ghz point to point between them. Then use 2.4 and 5.8 on 10mhz channels for the APs connected to 90deg 17dBi sectors) both 5.8Ghz and 2.4Ghz. You should point the sectors down as much as possible so that you are shooting into the next building. It will also help to prevent interference if you can stay between the buildings with the signal. You may have to use a RB112 or RB153 in the window of the clients office and let that unit connect to their wired network and it can also be a wireless repeater too. The RB153 can hold one SR5 to connect to the AP and then two R52s, one for the office lan and the other for connecting other offices that are on that floor and the floor above and below.

I use SR2s in RB112s with 9dbi omnis in hotels and they work great. I had one hotel the was concrete plus the walls were stucco with the wire mesh, so the whole hotel was a big faraday cage with each room boxed into its own little mesh cage. We had 14 200mW APs(CB3s) and we still did not cover the hotel very well until we changed to the Mikrotik setup (RB112,SR2,9dbi omni) After that we now have 100% coverage in the hotel and people in the building around the hotel are using the hotspot too.

I would think that if you want to start off with a small test setup you should buy a 90deg 17dbi sector and connect that to a RB112 with a SR2 and then get a RB112 with SR2 and 7dbi omni for the client side. Mount the AP setup on one of the roof tops pointing down the side of the building next to it and then test the client unit in the building your pointing at. Just test each floor at the ends. Try the test using 20mhz, 10mhz and the 5mhz channels. The SR2/5 will transmit on 5,10, 20 and 40mhz but they receive 10, 20 and 40. So I have been told.

There are other option to but I don't know what kind of control you have in the buildings.
If you had free run in the buildings you do the ptp to connect the building and the run to each floor with Cat5 for connecting AP's on each floor putting the AP's on each floor but alternating the ends of the building that you put the AP's. You may be able to just put one in the middle on every other floor. Only a little testing can tell you that.

One last thing, trust me when I tell you that you don't want to do a halfass test. If you cheep out on the test equipment you are going to think it's not possible to make it work.
And if you test with the good stuff and then deploy cheep equipment you will only been replacing the cheep crap with the good stuff later on.
I always try to test with what I am going to be using so that I don't have any nasty surprises when I deploy every thing.

I have already suggested them for a client units that wont need to be a good repeater.
Edit: never mind, his post got deleted.

hello Jober

i have a setup i want to do in an estate of about 300m radius. All the users are laptop users.

There is 80ft mast at the almost the center of the estate.

please kindly recommend the RB??, radio card and antenna to use with correspoing height to use on the mast.

thanking you ur much anticipated support.

hello Jober

i have a setup i want to do in an estate of about 300m radius. All the users are laptop users.

There is 80ft mast at the almost the center of the estate.

please kindly recommend the RB??, radio card and antenna to use with correspoing height to use on the mast.

thanking you ur much anticipated support.

I would use the RB532 because it can handle a lot more then the RB112. It's a little more but not having to upgrade latter is well worth the extra money.
I always use the SR2 cards for my hotspot setups so I would use it in your setup as well.
The mast you have isn't that tall so I think a 12 or 15dbi omni would be the way to go. Just make sure it's one with a 3 deg. electrical down tilt so you don't have a dead zone up close. Not that you realy will 80 feet high.

Also this being on a mast I would run LMR600 up the pole to the omni. It will make repairs a lot easier and I don't think the loss will be that much. You could use LMR400 but 80 feet is a long ways.
Lets see let us goto http://www.timesmicrowave.com/cgi-bin/calculate.pl
and we get:
LMR600 Total Run Attenuation(dB)=3.2 Cost for cable with Ntype connectors installed is around $167.50 US @ 75 feet.
LMR400 Total Run Attenuation(dB)=5.0 Cost for cable with Ntype connectors installed is around $107.50 US @ 75 feet.

wisp-router is the place I get most of my Mikrotik and antennas equipment. But you may need to find someplace a bit closer to you.
Heres a 12dbi omni that works well. http://www.wisp-router.com/mmWRI/Video/ ... 0Sheet.pdf
Heres a 15dbi that work realy good.
http://www.hyperlinktech.com/web/hg2415u_pro.php

Mikrotik has omni's too and they look realy nice but the price is a little to high for me to buy. I think you can get every thing you need direct from Mikrotik. Or you can check there website. It has these two company's listed:
Africa

David Savage
Cape Town, South Africa
Expert: TCP/IP, Routing, Wireless network design, HotSpots, Scripting, Training
Tel: +27-83-456-2002 (Mobile)
e-mail: d[at]etuan.co.za

Sunday A Folayan
Ibadan, Nigeria
Expert: Building large wireless networks, firewall, queues, VPNs, HotSpot, PPPoE, RADIUS and billing.
Tel: +234-803-497-7955 (Mobile), +234-2-810-5156 (Office)
Web: http://www.skannet.com.ng
e-mail: sfolayan[at]skannet.com.ng

One last thing, Please remember to ground the mast and you may also need to make a simple lightning rod to help stop static build up which will blow your radios. You can find some helpful info over at the wisp section of http://www.dslreports.com/forum/wisp.

Hello Jober,

thank you so much for the reply. please advice what hieght i need to place the Omni antenna on he mast. The tallest buiding in the estate is 3 storey.

Also, all the users are laptop users. i dont want any purchase of equipment but access to the network through the wifi card on the laptops.

thanks

"There is 80ft mast at the almost the center of the estate. "
I would put it at the top of that mast.

hi jober,

sorry for late response i was out of town...thanks for your suggestion we will test the whole scenario as you explained and with the equipmn we are going to use

regards

Hello All,

please how do i know 5Mhz ,10 Mhz channels on SR2. i have RB532/SR2 with hyperlink HG2412U 12 dbi omni. my anntenna hieght is about 50 ft high. my laptop cannot pick in some areas and in the buildings. below is my config

[admin@MikroTik] > /int wirel
[admin@MikroTik] interface wireless> pr
Flags: X - disabled, R - running
0 name="base_wll" mtu=1500 mac-address=00:01:B4:02:05:C0 arp=enabled
disable-running-check=no interface-type=Atheros AR5213
radio-name="gw.1_base" mode=ap-bridge ssid="hs_test" area=""
frequency-mode=manual-txpower country=no_country_set antenna-gain=0
frequency=2437 band=2.4ghz-b/g scan-list=default rate-set=default
supported-rates-b=1Mbps,2Mbps,5.5Mbps,11Mbps
supported-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,
54Mbps
basic-rates-b=1Mbps,2Mbps,5.5Mbps,11Mbps
basic-rates-a/g=6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps
max-station-count=2007 ack-timeout=dynamic tx-power-mode=default
noise-floor-threshold=default periodic-calibration=default
burst-time=disabled dfs-mode=no-radar-detect antenna-mode=ant-a
wds-mode=disabled wds-default-bridge=none wds-ignore-ssid=no
update-stats-interval=disabled default-authentication=yes
default-forwarding=yes default-ap-tx-limit=0 default-client-tx-limit=0
hide-ssid=no security-profile=default disconnect-timeout=3s
on-fail-retry-time=100ms preamble-mode=both compression=no
allow-sharedkey=no


pleae what advice do u have for me.

thanks