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wirelessdog

join:2008-07-15
Queen Anne, MD
kudos:1

UBNT 900mhz again

Has anyone done an A/B comparison between using a Rocket and a Loco with external antennas? I'm wondering if it could be possible the Loco's have the same issues as the NS2's with the external antenna port.



Inssomniak
The Glitch
Premium
join:2005-04-06
Cayuga, ON
kudos:2

said by wirelessdog:

Has anyone done an A/B comparison between using a Rocket and a Loco with external antennas? I'm wondering if it could be possible the Loco's have the same issues as the NS2's with the external antenna port.

Well. The loco is only one chain with an external antenna, the rocket with a dual chain antenna will obviously perform better.

I have lots of locos with external single polarity yagis and panels out there. A few rocket with 12 and 16 db dual pols, both configurations works fine.

I do find the the loco with internal antenna is lousy unless pretty close.
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gunther_01
Premium
join:2004-03-29
Saybrook, IL
reply to wirelessdog

I thought the 900Mhz loco used both chains while in external antenna mode. Or at least the option is there to use both, albeit with different signal strengths on the chains because of it
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»www.wirelessdatanet.net


Chele

join:2003-07-23
kudos:1
reply to wirelessdog

Don't forget that UBNT also has a 13(?)dBi MIMO yagi. They cost around $120(?), you have to buy them in a two-pack. We have two, one installed and one for testing--We have not been able to do ANY testing--too busy.



Inssomniak
The Glitch
Premium
join:2005-04-06
Cayuga, ON
kudos:2
reply to gunther_01

said by gunther_01:

I thought the 900Mhz loco used both chains while in external antenna mode. Or at least the option is there to use both, albeit with different signal strengths on the chains because of it

The loco can use both chains while using an external and one internal antenna. The external one must be horizontal. And I found this in most cases to work lousy if one chain had good signal and one had a bad signal. Simply using the external antenna exclusively worked better.

Ubnt has a 16 dbi mimo antenna for use with the rocket. It works well. It's heavy.
--
OptionsDSL Wireless Internet
»www.optionsdsl.ca

bburley

join:2010-04-30
Cold Lake, AB
reply to wirelessdog

I have given up on the idea of using Locos with external antennas. Every Loco with unbalanced (weak internal and strong external) antennas will mess up AirMax for the other clients. And using a Loco with only an external antenna defeats the purpose of AirMax.

If it isn't close enough to run the Loco with both internal antennas, it gets a Rocket with the dual polarity yagi. A Rocket with a dual-pol yagi is unbeatable.


wirelessdog

join:2008-07-15
Queen Anne, MD
kudos:1
reply to wirelessdog

I think you mean to say it defeats the purpose of MIMO because it certainly does not defeat the purpose of Airmax.



Inssomniak
The Glitch
Premium
join:2005-04-06
Cayuga, ON
kudos:2

Airmax works fine with one chain.

And yes internal+external kinda does not work well if the signal is unbalanced.

External works fine, even with Airmax.
--
OptionsDSL Wireless Internet
»www.optionsdsl.ca


bburley

join:2010-04-30
Cold Lake, AB

Perhaps I could word that a little differently. My understanding is that lack of balanced MIMO will degrade the AirMAX capacity of the AP which will eventually impact other clients.

In a hypothetical situation with only one AP and one client that is only using one chain, the AirMAX capacity cannot exceed 50% since 100% is dependent on both chains.

Now average all of your clients with dual chain at 100% and all those with single chain at 50% (ideal conditions) and you can see that AP capacity can be improved by converting as many single chains as possible to dual chain. This effect should be worse in reality because 100% dual chain or 50% single chain is not achievable.

Before capacity saturation is reached, this condition may not have much effect, but converting single chains is always harder by the time it becomes necessary.

Based on my understanding I converted all my single chains before it was necessary to save some work later.

Is there anything in my understanding that needs adjusting?



Inssomniak
The Glitch
Premium
join:2005-04-06
Cayuga, ON
kudos:2

A single chain client will require more time slots than a dual chain one. But it's also relevant to signals too.

So there is nothing wrong with 1x1 clients with good signal. For example I'd prefer a 900 loco with external antenna 1x1 with a great signal before I'd leave it using 2x2 with a weak signal, as that affected capacity more.

Use the priority setting too. Set lower clients to none and good ones to medium or high.

I have a lot of both mixed 1x1 and 2x2 on MIMO rockets with lots of customers and still get good throughput. I even have great performance on mixed legacy/M series airmax.

Could be just that I don't offer anything over 3 Mbps and or I don't have APs with high customer (more than 40) density. .?
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OptionsDSL Wireless Internet
»www.optionsdsl.ca


bburley

join:2010-04-30
Cold Lake, AB

I did lower the priority with the 1x1 clients with Yagis but then I started to think that if the AP did get congested, those clients would suffer first.

I am also using 5MHz bandwidth for improved distance and noise immunity which lowers the total AP capacity. In the past, with different and older 900 AP's, I have watched customer demand for bandwidth increase to the point of congestion. I wanted to avoid this scenario with the UBNT gear at all costs.

I am not sure where the point of congestion will be or if I will ever reach it, but it is a very competitive world and losing customers will cost more than the upgrade to Rockets and Dual-Pol Yagis.