2.4 Ghz vs 5.8 Ghz pro's and con's - needs some guidance.

[grubsner]

NanoBridge M5 5.5 km data link

I have a need to create a wireless link between two sites at a distance of 5.5 km. LOS has been confirmed. I will only create a wireless bridge and will not re-sell bandwidth so that would exempt me from licence etc.

The question now is: Do I use 2.4 GHz or 5.8 GHz? I believe both would work with the proposed distance. There might be some tree tops in the path but nothing major. The 2.4 GHz equipment is less expensive. Someone mentioned that I need a licence for 2.4 GHz but not for 5.8 GHz. Is there a TX power limitation? I want to purchase the equipment, just need some expert opinions.

I was considering a MikroTik 411 with 2.4 GHz radio on the remote site and a 433 with a 2.4 GHz radio at my home to cater for future expansion.

And no, there is no WUG at the moment to connect to.

What frequency (read cost) would work best for my requirement?

Thanks!
Grubs

 

[solo7]

2.4Ghz I believe can penitrate trees and buildings a bit better.

 

[protzkrog]

more interference on 2.4

 

[Ivork]

Solo7 is correct - 2.4Ghz if there is anything in the way is better (and remember to give a few meters above and below your line of sight - signal doesn't travel in a narrow beam like a laser).
I have found the TP-link 2.4ghz equipment very good - and the prices are very competitive -if you go that route. eg http://www.dbg.co.za

 

[wetkit]

Well, firstly do a scan with a laptop if possable at bith sites. This can give you a very good idea of how much 2.4 there is in the area.
2.4 is good for going through threes and stuff, but bad in a sence that most of the channels overlap and there is soooo many devices on 2.4 already.

5.8 would possably be the best option if you LOS is good.
I believe there is some of the wuggers out there that have very good results using these .... http://www.scoopdistribution.co.za/product_info.php?products_id=1045
Much cheaper than the Mikrotik.

Keep us up to date...

 

[grubsner]

more interference on 2.4

Thansk Protzkrog,

Just to clarify, what will the interference do? Will it reduce range or reduce connection speed? Can I use an alternative channel?

I am leaning towards the 2.4 GHz CPE's.

Grubs

 

[Freaksta]

I am on of the people who cant be on 5ghz because of my area and LOS non-existant, but i can still pick up fairly good signal and pull of our wug at about 1MB/s to 1.5MB/s. I go through many tree tops and maybe even some houses, and the 2.4ghz works very well, i am in a populated area and the channel i use does not have to much interferance. So i guess it all depends on you LOS and how much money you have to spend what you want the link to do etc...

 

[shogun]

I'm on 5.8GHz over 4km's, and get a brilliant connection - Full Speed on the 54Mbps link (we're using these: http://poyntingdirect.co.za/pWLAN-A0042/BridgePoynt---23dBi-5GHz.aspx). I pick up other 5.8GHz antennae at around 12km's away, although it's a bit weak at that distance (also not sure what might be in the way). I have very good LOS with perhaps a tree or two and the tip of a roof in the way.

For longer distances, if LOS is decent, i'd go with 5.8 as there's less likely to be interference from a bunch of home routers etc.

 

[grubsner]

Well, firstly do a scan with a laptop if possable at bith sites. This can give you a very good idea of how much 2.4 there is in the area.
2.4 is good for going through threes and stuff, but bad in a sence that most of the channels overlap and there is soooo many devices on 2.4 already.

5.8 would possably be the best option if you LOS is good.
I believe there is some of the wuggers out there that have very good results using these .... http://www.scoopdistribution.co.za/product_info.php?products_id=1045
Much cheaper than the Mikrotik.

Keep us up to date...

Wetkit, thanks for the details!

Good idea with the scan. I will do just that. Now that you mention it. there are plenty of antennas in the area. Just not sure of the freq. Will the NanoBridge also work as a "transparent bridge"? I have downlaoded teh manual and will have a look.

 

[Tacet]

Something about trees - keep in mind that summer is coming. We've had wireless links that performs well in winter, as the trees are bare. When summer comes the tree grows some silly leaves, which are filled with fluid, which isn't the best thing around for microwave. At 2.4 that shouldn't be too much of a problem, depends on how many trees you want to penetrate. We generally view trees as clutter, but we operate at much higher frequencies as which water absorption is a much more serious problem.

As for the frequencies themselves, neither 2.4 nor 5 are very high, and both should propagate very well. I've setup links of more than 7km before in the 5GHz band, but again, there was direct LOS. 2.4 could have more interference, which means that you signal can be degraded. That will result in lower bandwidth, and could even kill your link. Another thing to keep in mind is that if you're transmitting through a house, you could cause signal problems for the people inside that house. Someone is currently transmitting into my house, and it's only a matter of time before I get ticked off, start triangulating and kill his link. While the equipment are normally relatively good at choosing a channel, the more transmitters in the vincinity the greater the chances of interference. 5GHz is still a bit more open, so chances of interference is smaller.

Something few people realize is that there is a power limitation. I can't remember what it is, you'll have to research it. But keep in mind that the power limitation is on transmitted power, i.e.:

P_tx (dBm) + Gain_antenna (dB)

I think it is about 21 dBm, but I'm not sure. But basically, if you put a 30 dB antenna on, you may not transmit more than -9 dBm.

 

[grubsner]

Hi have ordered the NanoBridge 5GHz units.

next step is to configure and test.

I'll give feedback as soon as I have them up and running.

Thanks for all the replies!

grubs

 

[grubsner]

Feedback time:
I have installed and configured the NanoBridge M5's and they work well. I have about 5 trees that obstruct my LOS but the remainder of the path is clear.

I get about 54 Mbps link both ways. This does fluctuate during the course of the day. I'm still waiting to test the stability of the link during a rainstorm. Currently ythe link is stable with an average CCQ of 95%.

I'm happy with the performance but could be running too high powers setting to overcome the "tree attenuation".

I can really recommend these units. Solid and easy to configure. (Still having some trouble with the Firewall setup)