I'm looking for professional devices to build point to point.

trikin fired this volley in news:7d119813-3a32-4ea7- snipped-for-privacy@d10g2000pra.googlegroups.com:

Ubiquity.

5KM capability with their PS-2 bridge units. Low cost, too.

LLoyd

Thanks LLoyd but I am looking better devices or new brand becous I must build wireless for company (money) so this product must be less popular but device must be great.

trikin fired this volley in news:548bf6ad-c495- snipped-for-privacy@f40g2000pri.googlegroups.com:

Are you familiar with the Ubiquity products, or just assuming they're of poor quality because I said they were low cost?

The PS-2 bridges are "professional quality", weatherproof, POE, fully- configurable devices.

A pair of them, along with the gooseneck masts to mount them, cost $360, delivered.

LLoyd

Perhaps if you gave some idea of exactly what you wish to achieve someone may be able to help. For instance-

1. What is going to be the working distance.
2. What data rate do you hope to achieve 1Mb's or 1Gb's.
3. What reliability do you require and do you require a backup if the main link goes down.
4. Are you constrained by any power limitations or frequency limitations in the location you wish to operate the link.

7- 1.Distance 5km

1. 54Mb/s

3.This device should be work 99%a year. 4.Power max 200mW. 5 GHZ 802.11a

You will need to rethink some of this. I haven't seen much better than

-72dB sensitivity for 54Mb's at 802.11a and with the power output restricted to 23dBm you are unlikely to get a workable data rate of

54Mb's at 5Km. Link Calculator:-

If he can live with 48 Mbps at his end point, the PS2 will work fine.

At the 54 Mbps radio speed setting, the end point experience is only 24 Mbps. If he uses turbo mode, he can double it without sacrificing range as the receiver sensitivity for 54 Mbps and 108 Mbps is the same, its just that turbo uses a wider bandwidth aggregation.

90% uptime...wow, that means a daily annual average of 2-1/2 hours downtime. No matter, the PS2 with internal 19 dBi antennas will give him at least 25 dB fade margin for as little as around five minutes daily downtime.

Is that 19dBi on top of the +22dBm Tx power? If so it will take him over his limit.

Proxim Tsunami

Agreed. In addition, the 54Mbits/sec is probably the connection speed, not the throughput. At best, you'll get 25Mbits/sec thruput with a 54Mbit/sec "association" between wireless end points. I'll also assume 100baseT interface.

A somewhat simpler link calculator:

How to do link calculations:

You might wanna talk to a distributor, that carries a wide line of hardware:

For point to point bridges, see:

Also, 99.0% reliability means that it will be down 1% of the time. That's 88 hours per ear of downtime per year, which is sure to draw complaints. The reliability figure also directly determines the necessary fade margin for the link calculations. For 99% that's 18dB. That's fine but if you want to improve that to something more reasonable, like 99.9% (8.8hrs) downtime, you'll need 10dB more antenna or system gain, which is a huge jump. Methinks you're going to need to do some calculating and compromising.

I'm not familiar with the regulations in Poland, but if you're limited to 200mw, you're going to perhaps need big, ugly, and expensive one meter diameter antennas at both ends. Plugging into the link calculator for 5km (3.1 miles), 200mw (+13dbm), zero coax loss, and

-65dB rx sensitivity at 54Mbits/sec (if you're lucky), I get 42dB gain required for the antennas at both ends for a 20dB fade margin (99.0% reliability). Yep.

Dobre szczescie.

all the answers so far have suggested 802.11 wireless gear.

if you really need just point to point - maybe you should go and talk to a local carrier about a link.

they may have point to point fixed microwave support - but if they can rent you ethernet / dark fibre or SDH do you really care as long as you get enough bandwidth at good enough reliability and price point?

What limit?

In Poland you are allowed to use up to a 1W EIRP in outdoor applications in the channels 149-161 (5.725-5.850GHz).

I have deployed hundreds of Ubiquiti's Nanostations and Powerstations but for this application I will favour a custom solution using Mikrotik boards, Ubiquiti radios and MTI integrated antena enclosures. Ubiquiti integrated solutions have very nice hardware but the software tends to be buggy, even compared with Mikrotik's RouterOS (much much more capable BTW).

As example you can use a RB411AH routerboard, add a SR5 radio and mount it in a MT-900007 integrated enclosure with MT-485002 23dB antenna. With this setup you'll be able to establish connection at 36Mbps while staying into legal limits dialing down the radios' power to 10dBm.

If you want to connect at 54Mbps then you'll need separate enclosures and 32dB antennas.

Also you can substitute the board for a RB433AH to be able to install additional radios/antennas and use Mikrotik's Nstreme Dual for full duplex communication.

EIRP limits are different in Europe compared to the USA in some of the bands. e.g UK

2.4GHz 100mw 5GHz Band A 200mw Band B 1W Band C 4W From 2006 to follow the rest of Europe The OP has a Polish ISP and probably complies with these same limits. Note that he quoted 200mw MAX for his power output.

:

Thanks - that is very interesting - even though I did not ask the question:)

So in the U.S the limit would be at what???

The limits can be found in

and notice that the US allows a greater gain in the antennas for fixed point to point operation, which is not allowed in the UK.

Ok, that answers my question as to what limits in place.