Collecting experience with WIFI

[Jim]

All, I am using WIFI in small bar gigs these days. I was hoping we could start a thread that collects facts and experiences to help us all use it more effectively. First, a couple of thoughts. I don't like using WIFI at all. My experience has been that too often, it fails to work for no apparent reason (though there is one). Still, in the bar gigs and other small events, it can be and should be the right tool. And the corollary is, based on what I've experienced, I would never use WIFI for FOH in medium to large gigs or critical gigs.

So here goes. I recently purchased an ASUS RT-N66U dual band WIFI access point for use in the bars. I bought this router for a couple of reasons.

1. High throughput
2. External antennas which can be connected to high gain antennas
3. Two frequencies which behave differently in the same space and help to avoid other existing WIFI

So here's what I observed last Friday night at a gig in a small mountain town inside a very large, gym like, community hall. During setup and sound check, 5.0 GHz connected easily with no dropouts. Dropouts were observed by a disconnected remote application. Range was excellent around the hall. As soon as people started arriving the drop-outs started and the range dropped to about 35 feet in front of the band. At this point in the gig, the dance floor was empty so there were no people between me and the band even though there were about 100 people in the room. Other points:

• MAC address filtering was in use
• The router was turned up to maximum power transmission
• The antennas were on the side of the band but i had a nearly clear path to the access point.
• Channel selection was automatic.
• On my remote computer, I forced a connection to 5.0 GHz.

When the people started dancing the drop outs got so bad I decided to switch to 2.4 GHz to see if it would help. It DID an amazing job. only one dropout in the last set. I know the higher Freq would travel worse than the 2.4 GHz but I did not expect, in that space, it would be so dramatic.


So, Conclusions:

• I suspect that WIFI deteriorates not just from blocking the signal path but also from radio frequency collisions form all the cell phones.
• The idea that 5.0 GHz is a less used spectrum does not seem to help as much as when it was truly new.
• 2.4 GHz does propagate better and I will continue to force its use on my devices to start with.
• I am adding an omni +9 DBi antenna that I will mount on top of an extended mic stand, away from speakers to get the signal above the entire crowd.
• MAC address filtering did not help with connectivity issues. I had hoped it would stop all the phones from trying to connect and therefore suck up AP capacity.

Please share your experiences where you have some confidence with the conclusions. I hope we arrive at some useful operational guidelines for using WIFI in these working conditions.

[PhaseShifter]

At the end of the day, wifi is just plain old RF. Regardless of MAC filtering and hiding your SSID, it's going to be the sheer volume of RF chatter from all of the devices that will be the problem.

Also, the higher up you go on the frequencies, the more line of sight is required to maintain a quality signal, which is probably why you saw better results with 2.4 Ghz vs 5 Ghz.

It would also be ideal if the application was written in such a way that it wouldn't be hampered at all when things on the network started to get slow or disappear.

[Mike Roam]

I use wifi at foh on every gig. I have found it helps tremendously to use a utility called InSSider. I installed this free program on the remote computer. It uses the wifi adapter in the laptop to analyze the wifi usage in the room.
I look for an unused channel and use the utility program that comes with the router to change the router to an unused channel.
I have also found the apple airport express and extreme work very well.

Mike

[wd5don]

My experience with 5 GHz vs. 2.4 GHz also bears out your observations. We never had much luck with the higher frequency, despite having a clear line of sight from a second story router (perched on the balcony ledge) to a laptop less than a hundred feet away.

[Jim]

I use wifi at foh on every gig. I have found it helps tremendously to use a utility called InSSider. I installed this free program on the remote computer. It uses the wifi adapter in the laptop to analyze the wifi usage in the room.
I look for an unused channel and use the utility program that comes with the router to change the router to an unused channel.
I have also found the apple airport express and extreme work very well.

Mike

Mike, Thanks for that useful info. I'm going to try those utilities.
Jim

[Jim]

At the end of the day, wifi is just plain old RF. Regardless of MAC filtering and hiding your SSID, it's going to be the sheer volume of RF chatter from all of the devices that will be the problem.

Also, the higher up you go on the frequencies, the more line of sight is required to maintain a quality signal, which is probably why you saw better results with 2.4 Ghz vs 5 Ghz.

It would also be ideal if the application was written in such a way that it wouldn't be hampered at all when things on the network started to get slow or disappear.

Phaseshifter,
You are correct about the line-of-sight but there are many CDMA technologies similar to WIFI that perform quite well even with a high volume of devices - ethernet, cell phones etc. Network protocols have been proven to be effective in CDMA. WIFI algorithms just don't seem to accomplish this. Further, at these frequencies, the bandwidth should handle a room full of phones pinging the network. It just doesn't seem to work well enough with WIFI.

As for the applications, I agree. I have written a lot of large scale systems that can tolerate intermittent communications. You can't stop the outages but queuing, re-try and synchronization in the recovery is the key.
Jim

[Jim]

I use wifi at foh on every gig. I have found it helps tremendously to use a utility called InSSider. I installed this free program on the remote computer. It uses the wifi adapter in the laptop to analyze the wifi usage in the room.
I look for an unused channel and use the utility program that comes with the router to change the router to an unused channel.
I have also found the apple airport express and extreme work very well.

Mike

Mike,
Does the airport express/extreme require an apple computer to be used with them? Or do they not care what IP devices connect to them?
Jim

[Mike Roam]

The apple routers do not require apple computers.

Mike

[Doug_Danforth]

I don't think our experience is typical but I will share anyway.

We have done about 25-30 events over the past 2 1/2 years, ranging from bars to corporate events to backyards to fairs.

We typically run 2-3 remote laptops, one for FOH and the others for monitors. I have 100' of Cat 5 ready to run if necessary and I have never taken it out of the case. We have always used wireless and have never had any problem of any kind, except that our sound guy keeps hitting the WiFi switch on the FOH laptop and turning off wireless during set up.

We have a standard (cheap) D-Link 2.4 Ghz router and use MAC address filtering and we don't broadcast our SSID. We have never had to set up more than 100' from the stage so that has probably worked in our favor.

I know others have had issues with wireless, and we are ready to wire up if something gets AFU, but so far we have not had a single issue. We have been in some fairly congested venues - campus meeting room/concert hall in the student union. I counted 7 wireless networks I could choose from and there were a boatload of kids using laptops and phones.

Not many listening to us however ........

Doug

[Andy Follett]

I use wireless 100% of the time. Bars, country club rooms to outdoors 100-200' from router. The router has no external antenna and was off the shelf at Fry's for around $65 d link I think - not home at the moment. Point is its nothing special.

Big +1 on insider. Select my channels manually (not automatic). If I have the slightest glitch I start up insider and its been obvious my freq is being stepped on by another (or more than one) transmitter. I change the router channel (2.4) to something in the clear or with less interference and the problem goes away.

I've had an unusable wifi go to flawless operation just by changing the router channel.

I dont have much trouble but the few times i have, its been resolvable.

My experience. YMMV.