Question's about a particualr setup

[ljenkins]

Anyone have any experience with Bullet 2M's and a 15dBi omni antenna? I want to know about distance mostly in LOS or NLOS. I am pretty sure it breaks the EIRP, but this is real rural :P. Anyone tried this? All of the client equip will be Bullet2M and 24dBi Grid.

[netsplice]

it doesn't matter how remote you are... overlooking the fact the the bullets are not certified for anything bigger than a 6db omni. you could install the 15db omni just throttle back the power at the radio so that you are only putting out a total of 36. It doesn't matter how remote or how rural you are you never know who you could affect... and if you affect a amatuer radio operator that is operating in 2.4 you will get turned in.

as for LOS expect at 4 watts (36db) to go up to 8-10 miles los in clean spectrum with 24db grids on the bullets... (remember on the subscriber end you do not have to lower the power)

As for NLOS expect up to 1 miles depending on the type of trees... ones that are broad leaf and retain water will have less of distance then pine trees.

hope that helps...

[ljenkins]

Yea, I will probably go by the EIRP anyways, just had the 15dbi omni's in the warehouse already. I guess I could turn down the radio power as suggested. I was hoping someone had tried it even just using 36dBm at 4-6 miles with LOS, but we don't use omni's very often at all unless its real close range.

[WHT]

overlooking the fact the the bullets are not certified for anything bigger than a 6db omni. you could install the 15db omni just throttle back the power at the radio so that you are only putting out a total of 36. Unfortunately in the U.S., you can't do that. As its FCC certified for a 6 dBi antenna max, that's all you can use.

Lets say you had a Powerstation 2 that has a TPO of 26 dBm at 6 Mbps data speed. The PS2 is certified for use up to a 17 dBi antenna. So if you used it as a PtM emitter, you could still use a 17 dBi omni or sector antenna if you backed the TPO down to 19 dBm.

On the other hand, if you used it as PtP emitter (such as a CPE that connects to a single AP and only a single AP), then you can use a 17 dBi and reduce the TPO by 3.7 dBm, or a total TPO or 22.3 dBm.

[netsplice]

Unfortunately in the U.S., you can't do that. As its FCC certified for a 6 dBi antenna max, that's all you can use.


WHT >>> YES I understand that... I am hoping our fellow that is trying to make this setup work understands that also.

[netsplice]

Yea, I will probably go by the EIRP anyways, just had the 15dbi omni's in the warehouse already. I guess I could turn down the radio power as suggested. I was hoping someone had tried it even just using 36dBm at 4-6 miles with LOS, but we don't use omni's very often at all unless its real close range.

Yes 4 watts will go 4-6 miles clear LOS with an omni. You should have no problems if you are using 24db antennas on the CPE side.

However I STRONGLY SUGGEST you use something that is FCC certified and within the EIRP of the FCC for the band you are using.

[george]

4-6 miles? That is an 18 mile link budget, at least. How are you coming up with your numbers?

[netsplice]

you are only going to get 18miles if you have ABSOLUTELY no interference from any source.

I have one other company in this area using 2.4 and I am lucky if I can maintain 5 miles clear LOS with a 4 watt AP..

And now for the RANT:

The above post is the worst thing about these lists... it gives people false impressions as to what wireless can do and they run out buy the cheapest stuff they can find install it and then wonder why it won't work... The ubnt forum has at least had mostly common sense to tell people that they need to do A LOT more research before installing a PtP or PtMP system, such as site survey's, spectrum analysis, etc. And everyone wonders why there is SO MUCH interference in the area... I am in an area of 1500 people land locked by 9,000 foot mountain ranges, and the 2.4ghz band is so DIRTY from Wireless Routers that I can barely use it. There is one other company using 2.4 in the area non WISP related and they are using only one channel... they can't even maintain a 11 miles link using 1 watt amps and 24db grids.. (yes very bad I know but I trade tower space with them) So how in the world would you expect to get 18miles LOS in a multipoint environment and keep the customers happy.

end RANT

[WHT]

4-6 miles? That is an 18 mile link budget, at least. How are you coming up with your numbers?

4-6 miles...That's a pretty good estimate for 24 Gig.

36 dBm EIRP omni AP delivering sufficient signal for a 15 dB fade margin towards a 10 dBi CPE antenna, unless you know of any CPE radios rated at more than 10 dBi antenna...other than the 17 dBi PS2 internal. Which is a 7 dBm improvement, and that would double your range out to eight to twelve miles.

[WHT]

LOL...that reminds me of when Mike was reading his email across the conference table from me back in April. He rolled his eyes when some N00B wanted to know how to set up a 50 mile link.

[george]

as for LOS expect at 4 watts (36db) to go up to 8-10 miles los in clean spectrum with 24db grids on the bullets... (remember on the subscriber end you do not have to lower the power)

Unless the rules have changed, you're still subject to the Part 15 3:1 rule in 2.4 in FCC land on the client end.

"The FCC ruling states that for every 1dBi the Intentional Radiator is reduced below the initial 30dBm that the antenna gain may be increased from the initial 6dBi by 3dB."

Last time I checked that works out to 48dB EIRP on the client end max with a 24dB grid. As the Bullet M2 HPs are capable of way over 24dB conducted power, the difference matters.

As you say, it helps to know what your're talking about. And I'm not even in FCC land.

[george]

you are only going to get 18miles if you have ABSOLUTELY no interference from any source.

Rubbish, your environment is not the whole world nor is mine, which is why I didn't go nuts over the whole 15dB omni thing to start with.

There may be some remote villages in the Himalayas where a 15dB omni is still a good idea, but I haven't seen one for years.

See the link calculation pic below. Most of the freaking world can work with a -69 signal if the rest of the system design is good. That's a -66 at the AP btw which is even better. In my world the AP sees the worst of the interference generally.

Maybe you can't that doesn't mean you should be encouraging others to run that kind of over-powered BS where they don't need to.

I asked you where you got your numbers, because it wasn't from any SOM calculation I've ever seen. Once more, where did you get your numbers, or did you pull them out of the air (pun intended)?

I have one other company in this area using 2.4 and I am lucky if I can maintain 5 miles clear LOS with a 4 watt AP..

And now for the RANT:

The above post is the worst thing about these lists... it gives people false impressions as to what wireless can do and they run out buy the cheapest stuff they can find install it and then wonder why it won't work...

Rubbish. You chose to read that into it. I asked you a simple question, where did you get your numbers, because the SOM calculation suggests that with most "normal" noise floors all you are doing is adding to the pollution coming from your buddy with the 1 watt amps (that are also likely to be highly illegal). If you want the section about amps having to be part of a fully FCC certified system I will be happy to look it up for you.

The ubnt forum has at least had mostly common sense to tell people that they need to do A LOT more research before installing a PtP or PtMP system, such as site survey's, spectrum analysis, etc.

The UBNT forum is about average in this regard, and WAY below the standard you would expect for debate in WISPA for example. Not to mention the Part15 and ISP-Wireless lists at their peak. I read over twenty thousand posts in 2001 before I even dared to open my mouth on ISP-Wireless. And the smart people from those lists are mostly still around.

And everyone wonders why there is SO MUCH interference in the area... I am in an area of 1500 people land locked by 9,000 foot mountain ranges, and the 2.4ghz band is so DIRTY from Wireless Routers that I can barely use it.

One doesn't wonder at all. That is getting to be normal now, which is why most thinking people in that situation don't use 15dB omnis.

Speaking of most thinking people:

The don't use any omnis.

They use sectors, preferably very narrow ones.

They take advantage of the opposite polarity to the main noise source.

They use narrow channels.

They use more primitive modulations and don't try for maximum speed everywhere off a single access point.

They use some finesse and RF engineering instead of cranking up the biggest, baddest radio they can find.

This trend to higher and higher output power is largely bs. Its a nice marketing ploy to keep the uninformed and unwashed happy but that and wide angle CPE are screwing up the spectrum in all our bands big time. Motorola started it with their Canopy interaged CPE, unfortunately everyone else has piled on.

If you use the correct antenna and system design you need very low conducted power to get the job done.

There is one other company using 2.4 in the area non WISP related and they are using only one channel... they can't even maintain a 11 miles link using 1 watt amps and 24db grids.. (yes very bad I know but I trade tower space with them) So how in the world would you expect to get 18miles LOS in a multipoint environment and keep the customers happy.

end RANT

So turn their sorry *** in. The FCC would probably love to know about it if you presented your case the right way. Oh whoops, you do business with them.

We have problems with perfectly legal stupidity in 900 caused by the evil Canopy everywhere that we can't do jack about. YOU at least have the option to get your problem stopped.

Now if you really want to rag on me some more, I'm your guy!

George

[george]

4-6 miles...That's a pretty good estimate for 24 Gig.

36 dBm EIRP omni AP delivering sufficient signal for a 15 dB fade margin towards a 10 dBi CPE antenna, unless you know of any CPE radios rated at more than 10 dBi antenna...other than the 17 dBi PS2 internal. Which is a 7 dBm improvement, and that would double your range out to eight to twelve miles.

Do try to keep up please WHT, there's going to be a quiz later. This entire thread is about Bullet M2s with 24dB grids at the client. Of course the numbers change for the worse if you have different clients...

[shapiros]

I read over twenty thousand posts in 2001 before I even dared to open my mouth on ISP-Wireless.

WOW, glad I am not the only one. I lurked around reading for about 6 months in forums from Motorola to Mikrotik before landing on you guys doorstep. It has definitely been the RIGHT choice!

Sig

[george]

It is brutal when you're just getting going, although the gear now is so much better its maybe a little harder to make a really bad decision. And there is a LOT more help available on the forums than there used to be.

I came from a Navy radio and microwave background, plus had advice from a 30-year six gig long-line veteran who helped me avoid some really silly decisions.

The cheaper gear also helps. At least if you make a mistake it probably won't cost $20k any more to learn from it...

George

[ljenkins]

thanks for the info guys. so even if I backed down the bullet unit to equal 36dBm of output with a higher gain omni I still can only use a 6dBi antenna?

***also took your advice and I got a few 6dBi omni's coming soon***

[george]

That would be correct. Its going to be less than optimal in most circumstances because:

1. You are going to pick up noise from every direction, you lose the ability to 'turn your back' on a noise source.
2. You are not going to hear anything very well because of the low receive gain of a 6db omni. Its going to be a bit like working with ear plugs in.

Is there no way you could sneak a higher gain sector into the mix instead of the omni? You would likely get much better results...

[ljenkins]

yea, I've got one spare 90 degree 14dbi that I am probably going to use for this...but I was also thinking I can get the signal to this area I am trying to serve with a PtP grid+bullet on each side and serve the customers with an omni that is closer to them. but If I can hit the customers from my source with that sector antenna I will probably just do that.

Another big problem is this stuff needs to be done within a month or it won't happen and unfortunatley I don't think ubiq is going to be able to get the 2.4M nano's and rocket's out before this is done. So this area of customers will be stuck a 1x1 11n for a long time...sigh.

[george]

You're certainly on the right track. If you can get an omni in close and low you will definitely do better, and if you can get the sector working it may do better yet, although that is hard to quantify.

We run a bunch of hotspot-type stuff at streetlight level using 7dB omnis with generally good results. That's all low enough that it only gets bothered by local wireless routers and we can generally juggle channels enough to get by. Its great that most people don't bother to move off channel 6!!

I'm with you, it feels like it may be a while before the 2gig 2x2 stuff actually lands in a mailbox near me. I've got two weeks of shipping +/- on top of the time they arrive at a distributor.

[netsplice]

Now if you really want to rag on me some more, I'm your guy!

George

I wasn't raggin on you. the rant was a general rant... (i.e. BAD DAY!!!!)

If everyone played by the rules then it would be a perfect world and we would all be happy. However it isn't a perfect world and everyone wants to start a wireless ISP it seems.. some with very good intentiions others because they want to share their cable connection with their friend who can't get it.

As pertaining to the other major 2.4 user I would love to turn him in as I said doing business with them makes that a horrible move in my life. I have 40 users connected to that tower, (multiple ap's)

[george]

No worries. I took it as an attack, and as I'm usually up for a scrap........:icon_mrgreen:

I know you've been in this business for years, it can be a tad frustrating dealing with the eternal quest for more power from the N00Bs, bless their pointed little heads!

I really liked the old days when 60mw was all the teacher would let you have, and complicated shots required finesse.

The world was a much quieter place instead of the crap we have to deal with now. And I REALLY hate amps so you have my sympathy.

George

[netsplice]

same here... but it did cause you to through out some extremely valuable information for other people to find and hopefully use.