After gaining some good experience with MT and XR2s and a heap load of SR and XR9s in rural environment, Im planning my metro wireless infratructure for downtown.. This is how I wish to set it up..

Each AP/Relay site would include such;

AP would be installed on corner of buildings enabling coverage in four directions down streets.

4 XR9s/panel antennas in HPOL for backhaul creating a dual radio backhaul setup.
1 XR9 Omni for commercial Stationary and Vehicular services.
1 XR2 Omni for private sector WiFi access.

minus 2 XR9/panels for just a straight relay in between a major intersections if needed.

Backhaul XR9s on AP will run on individual channels and XR9 Omni will run on channel with the least noise.

Comment not needed for the XR2..

Planning on using RB600A with daughter board for APs. - Will have to build a large PC based system as main initial AP connected to hardwire. Infrastructure will offer Internet connectivity as well as just simple data connectivity throught the infratructure, kind of like a HUGE LAN for business`s who do business with eachother within the network coverage area (these connections wont neccesarily require internet access)

Plan to run 20 mhz with nstreme on backhaul from AP to AP throughout the infrastructure.

Question.!
- Would this be an ideal setup for a mesh network, or just keep as a normal wireless wds network as the AP will be just below roof level in anycase.. I dont see a point in packets trying to find the fastest route when they only have one strong AP near by in the first place..

- How big could I make this cell, could I create one huge cell covering the entire large downtown metro areas?(Downtown equals couple million residents) or will I have to break it up into several small cells? If so whats the approx max AP setups I can handle?

Have already tested noise in the downtown area where I want to start this, there is definite noise but I think its within reason, around the mid -80s give or take all the time.. I have some situations up north with these noise levels and I dont really have issues..

Why 900? Penetration.!! The 2.4 Omni will just be hopefully a little rev generator as a pay as you go hotspot..Just to compliment the network and also helps ppl discover your network in the first place, not my main target audience, but if your going to build a multi radio large scale network, might as well add the extra thing hear and there so yah dont have to go back and add after if you keep kicking your head saying that you should have put it up...

Any evident negative issues an experienced wireless operator sees here?

Would like possible suggestions ons what would make this general setup better..!

Thx all.. Hope to build the first private sector multi radio wireless infrastructure in a major metropolitan city in Canada..!! The first city wide wireles infrastructure period for that mater.. hihi.. Wish me luck!!!!!!

comments pls...

Why don't you use 5 GHz? It will give far more bandwidth than 900 MHz.

Well, my thought on that is that most the streets hear have tress in the sidewalks that are preety damn big most of them. They can rise up to like 40 ft or so. There are several along side the streets with a one block radius. With heavy rain and most of all, heavy snow and freezing rain, my impression is that 900 will penetrate better with less signal degradation. I also wont require as many APs as with 900. I realise that the 2.4 radio wont prpagate as well as with the 900 but thats not really my goal in anycase to have the 2.4 signals really side by side without any drops. ifcourse ill try and make it so they are as close as possible for best reception but not main goal.

What throughput do you think ill get with nstreme in 900 with signal in the mid -60,s running g?

With heavy rain and most of all, heavy snow and freezing rain, my impression is that 900 will penetrate better with less signal degradation.

I have read, here on the forum, that 5.8 GHz works far better than 900 MHz in the rain.

You can probably get like 10 Mbps TCP at 900 MHz with a 20 MHz channel.

Actually, my 900MHz AP works quite well in the rain. Signal is normally -68, its -53 in the rain. My initial test shot was -83, low 70's when it rained, rock solid.

Too bad there's so much noise above and below the band... Gotta get a filter. My 5GHz p2p link loses about 3dB in average rain, heavy thunderstorms we've been having show about a 6dB loss.

I personally would test a 900MHz link, at least the longest of your shots, before I invested in the shot you're talking about. My noise will drop to -76 randomly here.

Well,, after some initial tests, I think its safe to say that the bandwidth between 900mhz radios and 5.8mhz radios juste doesnt compare.. Will be replacing my 900 backhauls with 5.8mhz..... Hopefully I can get 50mb+ in single nstreme and if need be, 150mb+ in dual nstreme.. I am tempted to try the damn sr71 cards, but the PCB boards havent shipped yet...

Don't think it would be legal to use xr71

Well,, after some initial tests, I think its safe to say that the bandwidth between 900mhz radios and 5.8mhz radios juste doesnt compare.. Will be replacing my 900 backhauls with 5.8mhz..... Hopefully I can get 50mb+ in single nstreme and if need be, 150mb+ in dual nstreme.. I am tempted to try the damn sr71 cards, but the PCB boards havent shipped yet...

Share with us your 900mhz test results. That's what this forum is for: sharing and learning.

You are not going to get 150 Mbps in dual nstream, don't even dream about it.
50 Mbps in Turbo mode is possible but is going to be very difficult. Plan for 40 Mbps.

ah yah,, thought I could get atleast close to 100mbs Damn will hve to test this big time..


as far as the sr71`s they hav already been cetified by industry canada, why wouldnt they be legal to use??

my bad.
I was thinking of the 700MHz xr7.

I would create virtual APs on the 4 XR9, and save the Omni. You can still have separate networks, and less congestion in the air...

mickeymouse690 -

I don't know how everyone missed this but you don't have enough channel space to run that many 900mhz that close together.....

Your very best bet is to run the 5ghz as backhauls between sites. That will at least free up some 900mhz channel space.

If you are going to use 2.4ghz be mindful that without filters on your 900mhz systems that you will get interference from the 2.4ghz in the 900mhz (because of the way the 900mhz is 'manufactured' from the basic 2.4ghz carrier).

If you are supplying DC directly to the RB600 (or whatever RB you are using) 6 high power radios (XRx) might just be too much if all of them are working at the same time.... You may want to maybe stick with 3 per and use that as the base with ethernet inbetween to keep the two units connected. Speaking of 6 cards... You'll have a tough time with 2.4ghz and 900mhz in the same box.... Few folks have been succesful at having both in the same enclosure....

What did you test the 900mhz spectrum noise with - an XR9/SR9 or a real spectrum analyzer? It makes a big difference.... One obvoius issue is if you tested w/XR or SR9 in the narrow channels (5 or 10mhz) then you'll not see a lot of the noise out there, if you test the other way - standard 20mhz channel - you'll miss the 'g' mode noise generated by 2.4ghz 'consumer' grade radios...

Well - just some info/thoughts for you to ponder before you drop 10K in equipment costs.

R/

GN - Appreciate your post a great deal, good input. Think I will go with the 5ghz backhauls as there should be more bandwidth that I can get.. The power issue I thought of, not sure what they all will consume in one RB600 all the cards. Will have to test that out..

I tested my noise with XR9 in g mode.. Are my readings that off??

Also in my rural WISP network,, I have a couple APs that have one XR2 with SR9 right beside each other in a x386 based system. Dont seem to have any issues there but then again yah never know.. They have been running sweet for a year now..



---

Other poster mentioned creating Virtual APs ..!! ?? What does he mean? I dont get the safe the OMNI comment.. The Omnis are for client connections on there respective freqs..


Thx guys..

mickeymouse690 -

If you are going to use 2.4ghz be mindful that without filters on your 900mhz systems that you will get interference from the 2.4ghz in the 900mhz (because of the way the 900mhz is 'manufactured' from the basic 2.4ghz carrier).

R/

What would the issue be with running 2.4 and 900 together?

iam8up -
There is no issue with running 2.4ghz and 900mhz together. What I said above was be careful running a SR9 and SR/XR or any other 2.4ghz card with it.

The reason - the SR9 the data is first formated and sent out a 2.4ghz very low power amp, it is then fed to a 900mhz down converter/amplifier. The result is a mostly 900mhz signal. The filtering and the conversion are not all that clean on an SR9. If you look at the output on a spectrum analyzer you'll see the 2.4ghz output from the SR9 all across the 2.4ghz band where it SHOULD be only 900mhz.

Now - depending on your channel selection in the SR9 you can interfere with your own 2.4ghz wireless. Careful channel selection is required and the amount of traffic seen on either interface can also have an impact - because as I just said - the filtering and frequency conversion on the SR9 is NOT very clean.

The XR9 has better filtering and they changed the way the 2.4ghz is converted to 900mhz - the net effect is there is a lot less impact on the 2.4ghz with an XR9 card. There is some residual 2.4ghz but it is very low and does not seem to have the same devastating effect the SR9 did on 2.4ghz systems - it still can affect a 2.4ghz system - just less of an effect.....

I hope this helps...

mickeymouse690 -
Each SR/XR card consumes almost 5 watts. I believe that the RB600 uses what 7-8watts for the RB600 itself. I also don't quite remember the spec quite but if I remember correctly the RB600 power supply can do about 30-35watts - you also have to be mindful of what the power supply you have feeding the RB 600 can do (most are roughly 15 watts) and how long the PoE run is...remember that CAT5 is ONLY 24 gauge and can only carry about 15watts before you start generating a significant amount of heat and line loss for power.... You can get around that aspect (the power) by using alternate methods - bulid your own cat5 power inserter/extractor - basically use a seperate cat5 line, hook 4 wires to your + side, 4 wires to your '-' side, add a plug at the far end and plug that in to your RB600, that should be more than enough total wire to run about 60watts with minimul line/power loss.

If you are using the XR9 then you'll want to do freq checks in BOTH b & g mode. Even then certain types of signals will not necessarily register correctly but between the two modes (b & g) and the various channel widths b/g/10/5 - you should be able to 'see' the majority of the signals and most noise generators out there....

As to your luck w/the SR9 and XR2 - you must have the XR2 on channel 11 and the SR9 in channel 3 or 4, also - you have them mounted on mpci to pci card converters don't you? And they are not on the same mpci to pci adapter card are they? So there is some shielding between the two - lucky you! The amount of traffic on the two interfaces can also be a factor in to how much they interfere with each other...

Ok guys - have fun!

R/

Thom

iam8up -
There is no issue with running 2.4ghz and 900mhz together. What I said above was be careful running a SR9 and SR/XR or any other 2.4ghz card with it.

The reason - the SR9 the data is first formated and sent out a 2.4ghz very low power amp, it is then fed to a 900mhz down converter/amplifier. The result is a mostly 900mhz signal. The filtering and the conversion are not all that clean on an SR9. If you look at the output on a spectrum analyzer you'll see the 2.4ghz output from the SR9 all across the 2.4ghz band where it SHOULD be only 900mhz.

Now - depending on your channel selection in the SR9 you can interfere with your own 2.4ghz wireless. Careful channel selection is required and the amount of traffic seen on either interface can also have an impact - because as I just said - the filtering and frequency conversion on the SR9 is NOT very clean.

The XR9 has better filtering and they changed the way the 2.4ghz is converted to 900mhz - the net effect is there is a lot less impact on the 2.4ghz with an XR9 card. There is some residual 2.4ghz but it is very low and does not seem to have the same devastating effect the SR9 did on 2.4ghz systems - it still can affect a 2.4ghz system - just less of an effect.....

I hope this helps...

mickeymouse690 -
Each SR/XR card consumes almost 5 watts. I believe that the RB600 uses what 7-8watts for the RB600 itself. I also don't quite remember the spec quite but if I remember correctly the RB600 power supply can do about 30-35watts - you also have to be mindful of what the power supply you have feeding the RB 600 can do (most are roughly 15 watts) and how long the PoE run is...remember that CAT5 is ONLY 24 gauge and can only carry about 15watts before you start generating a significant amount of heat and line loss for power.... You can get around that aspect (the power) by using alternate methods - bulid your own cat5 power inserter/extractor - basically use a seperate cat5 line, hook 4 wires to your + side, 4 wires to your '-' side, add a plug at the far end and plug that in to your RB600, that should be more than enough total wire to run about 60watts with minimul line/power loss.

If you are using the XR9 then you'll want to do freq checks in BOTH b & g mode. Even then certain types of signals will not necessarily register correctly but between the two modes (b & g) and the various channel widths b/g/10/5 - you should be able to 'see' the majority of the signals and most noise generators out there....

As to your luck w/the SR9 and XR2 - you must have the XR2 on channel 11 and the SR9 in channel 3 or 4, also - you have them mounted on mpci to pci card converters don't you? And they are not on the same mpci to pci adapter card are they? So there is some shielding between the two - lucky you! The amount of traffic on the two interfaces can also be a factor in to how much they interfere with each other...

Ok guys - have fun!

R/

Thom

Epic post. If only everyone could post this must information! =)

Thank you very much, Thom!