5 GHz band flooded with other 5 GHz routers

[bchiang83]

I know that the 5 GHz band is supposed to be the band to use for less interference, but when you live in a big apartment complex that looks like this http://imgur.com/a/zwSne what types of effects are seen to the user? Does the interference from all the different 5 GHz routers manifest as random ping spikes and is there anything that can be done?

 

[bchiang83]

This is really the same question you asked here: http://www.snbforums.com/threads/rt-ac66u-5ghz-ping-spikes.34951/

That post is much more detailed and while similar, it actually asks a different question at the end. I'm trying to figure out here if all the 5GHz routers around me causes ping spikes because I can't find any info on this on google. Anything I search about the effects of crowding on the 5 GHz band just directs me to articles telling me to use 5 GHz because 2.4 GHz is too crowded. Any info would be appreciated, as you can see, I've taken extensive efforts to figure out what is causing the problem.

 

[L&LD]

The 5GHz band has many advantages over 2.4GHz. Even though inssider can see many different networks available, the thing it can't show is network utilization.

This is one reason why you should just ignore what utilities like inssider show and simply manually choose a channel and test it (in your normal use, not 'stress' it) to see which channel provides the most throughput with the least latency. inssider can't show you that (it can only see WiFi channels, it can't see other WiFi interference causing issues).

Test each channel methodically, keep notes and you will soon know which is the best channel for your environment and usage. No, there will not be a perfect channel. But there may be one which is better than the one(s) you're currently using.

 

[HTMLSpinnr]

With newer AC technologies, your router may be consuming 4 (80MHz), or 4+4 (160MHz) channels in that band, which does make it more highly utilized. InSSIDer may not show that, and may only report the control channel.

Fortunately, 5GHz range is nowhere near 2.4GHz, which may help. One thing to look for is overall "utilization" and how that's represented with the noise and SNR value on each channel. If you're seeing high noise floors on specific channels (i.e. -60dBm vs -85dBm), or SNR at just 10-15dB, then that channel is nearby and probably highly utilized and you should avoid it. You may need to turn to laptop tools to get those types of values, however.

On the flip side, 2.4GHz suffers, especially in apartment complexes, from other sources of interference. Baby monitors, cordless phones, and leaky microwave ovens are a nightmare. That, and neighbors who think using 40 or 60MHz of bandwidth on 2.4GHz is an okay thing to do in congested spaces.

 

[pete y testing]

Does the interference from all the different 5 GHz routers manifest as random ping spikes and is there anything that can be done?

change the filter on inssider to -70db or less as anything over -70db really isnt an issue as its too low to effect you , you will then get a better picture of what channels are used close to you and which you can use for the least interference

however if that was me i would be looking at getting anything i could on ethernet even if you have to get a cable installer in to do some wiring

pete

 

[L&LD]

Fortunately, 5GHz range is nowhere near 2.4GHz, which may help. One thing to look for is overall "utilization" and how that's represented with the noise and SNR value on each channel. If you're seeing high noise floors on specific channels (i.e. -60dBm vs -85dBm), or SNR at just 10-15dB, then that channel is nearby and probably highly utilized and you should avoid it. You may need to turn to laptop tools to get those types of values, however.

That isn't utilization, but I can't think of the term you're trying to describe right now.

Network utilization (on any specific channel) cannot be measured or guessed at by free/simple utilities like inssider or such.

That is because they don't show how much data is actually being pushed through the air.

Interference can also be seen in 5GHz networks too. Using the same channel as other nearby routers may even be beneficial (for both bands), because then the routers are working together, sharing their time slices, rather than just seeing each other as interference which causes them to keep re-trying the transmission and in turn, making themselves interference to the other routers too.

 

[sfx2000]

If one is truly concerned about connection stability - no substitute for going back to the wire...

WiFi by it's nature, it is going to be bursty, as it is a shared medium, and AP's and Clients within range of your WLAN will consume airtime...

 

[bchiang83]

Thanks everyone; this is good info. I'll try putting in a -70dB filter later and see if I can pick a better channel. I've already set my bandwidth to 20MHz to try to eliminate as much interference as possible.

My main question was: does having a lot of 5 GHz routers around you cause interference on your network in the form of random ping spikes? It seems like that answer is yes because the interference will cause transmission errors that will force the router to resend a packet which means that the previous one was packet loss.

 

[sfx2000]

Thanks everyone; this is good info. I'll try putting in a -70dB filter later and see if I can pick a better channel. I've already set my bandwidth to 20MHz to try to eliminate as much interference as possible.

If you leave it at 80MHz, you give the chipset options and opportunities to reduce interference from adjacent AP's - remember, you're only seeing the Beacon frames with tools like InSSIDer, not actual traffic - and Beacon frames are much higher gain than traffic frames - don't worry about it so much...

 

[HTMLSpinnr]

That isn't utilization, but I can't think of the term you're trying to describe right now.

I'm thinking of layer-1 utilization and interference. Constant streamers like cameras, Rokus, etc. could be "measured" that way, unless the stack is ignoring recognizable beacon/data frames as noise.

 

[L&LD]

I'm thinking of layer-1 utilization and interference. Constant streamers like cameras, Rokus, etc. could be "measured" that way, unless the stack is ignoring recognizable beacon/data frames as noise.

That still doesn't seem within the realm of possibilities of a free utility like inssider or similar.

 

[bchiang83]

If you leave it at 80MHz, you give the chipset options and opportunities to reduce interference from adjacent AP's - remember, you're only seeing the Beacon frames with tools like InSSIDer, not actual traffic - and Beacon frames are much higher gain than traffic frames - don't worry about it so much...

So you're saying that putting it at 80MHz might actually be better to reduce interference?

 

[sfx2000]

That still doesn't seem within the realm of possibilities of a free utility like inssider or similar.

Kismet actually can see activity on a channel, and measure it - but it's not for Windows, and it's not for most folks...

 

[sfx2000]

So you're saying that putting it at 80MHz might actually be better to reduce interference?

80MHz channels - the WiFi chips do have some agility and flexibility to move around inside that 80MHz channel - on 20MHz of that channel is used for the beacon, but Broadcom, QC-Atheros, Marvell - they can map around 20MHz interfering frames if found... I'm over-simplifiing it, but they do have a fair amount of latitude on which frequencies within that 80MHz channel (in an 80MHz channel, there's 4 blocks of 20MHz - 1 primary, and 3 supplementals)...

 

[HTMLSpinnr]

That still doesn't seem within the realm of possibilities of a free utility like inssider or similar.

Agree, and indicated that in my original reply. Linux (LiveCD/USB if needed) and MacBooks can easily show it on many adapters.

Sent from my XT1095 using Tapatalk

 

[thiggins]

80MHz channels - the WiFi chips do have some agility and flexibility to move around inside that 80MHz channel

If this is true, why do enterprise networks run 20 or 40 MHz B/W in 5 GHz?

 

[thiggins]

Does the interference from all the different 5 GHz routers manifest as random ping spikes and is there anything that can be done?

Wi-Fi is a shared medium, where devices using the same channel must first check to see whether the channel is busy before transmitting.

If the channel is very busy, a device may have to wait longer to get a time slot. Longer wait = higher ping time.

Normal channel use is not "interference", per se. Think of bumper-to-bumper traffic. Sometimes you speed up, sometimes you slow down. Sometimes you sit...

 

[System Error Message]

The cool thing about wifi routers like asus is that you actually get more 5 ghz channels to use than ISP given routers. I find that people barely upgrade their ISP given routers and those that buy their own routers usually only do so 5-10 years when their old router becomes the bottleneck significantly. For example in the UK, the AC88U has 1 channel that is unused by all ISP given routers that is used in the UK which is the highest common 5Ghz channel among router manufacturers like asus or netgear or even dlink (basically dependent on the hardware used). The 3 band radio, the 3rd radio uses channels that no ISP given router uses in the UK.

So find out what sort of ISP routers are in your area(just look for their GUI simulators or configuration summaries or even wikidevi for details of what channels they use and get a router that has a channel they dont have. The reason is that there are so many routers out there, many of them ill-configured and their auto will tend to use the channel your AP uses even if theres a lot of extra space. So getting a router that has channels not used by ISP given routers is something to look for.

In the US only transmit power is what the FCC is worried about but the US actually has the most 5Ghz channels available world wide. However router manufacturers only make routers with less than half the allowed channels in the US, they say its FCC Restrictions but the main thing about fcc restrictions are firmware tinkering and power transmission but they restrict channels because they're afraid of the FCC such as fines and banning products/recalls.

 

[sfx2000]

If this is true, why do enterprise networks run 20 or 40 MHz B/W in 5 GHz?

Mostly to fit within an existing 11a/11n floorplan - and there is still benefit that 11ac can offer there.

 

[thiggins]

Mostly to fit within an existing 11a/11n floorplan - and there is still benefit that 11ac can offer there.

They don't do it for channel planning purposes because 80 MHz eats up too many channels?