Why does my Time Capsule switch to the 5 GHz band and lose connection?

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Level 1

22 points

Why does my Time Capsule switch to the 5 GHz band and lose connection?

I have a 3 year old Time Capsule with the dual band 2.4/5 GHz wi-fi router. When I pull down the network list I see my "(network name)", which is the one I normally choose (check). Also available is the "(network name) 5GHz", which I normally NEVER select myself. But of course "known networks are joined automatically."

So, sometimes lately I will suddenly loose my interet connection while browsing or working online. The little fan icon on the task bar greys out and has a "!" on it.

Invariably, when that happens, if I pull down my network list, I will be connected (checked on) to "(network name) 5GHz". If I manually check "(network name)" (ie: the 2.4 GHz band), I immediately get my internet connection back. This will happen 1 to 3 times per day and always when located in the same place in my house (ie: I'm not moving around). This is happening with the wi-fi connection of my 3 yr. old MacBook Pro. My wife has occasionally been online with her 2 year old MacBook Pro and NOT had the same experience, so the band swithching/internet connection loss MAY be originating in my laptop, not the router. But the fact that she's stayed online suggests that this problem is coming from either the router or my laptop's wi-fi and not my dsl modem or dsl line signal.

Because of this, I have taken to checking my network selection periodically even when everything's working fine. Sometimes I will find that I am connected to the 5 GHz band unbeknownst to me, and my internet connection is just fine! It stays fine if I manually check the 2.4 GHz band network name, and also if I go back to the 5 GHz band.

So, in short, I'm not sure if I'm loosing my internet connection because my laptop/router are choosing to switch bands (I know reception properties are different on the two bands), or it this kind of spontaneous switching back and forth just goes on all the time and my loss of internet connection is due to something else entirely. I do have a phone co. supplied dsl over my landline and I suppose that COULD be the source of my problem, but I find it highly suspicious that ALWAYS when I lose my connection, I find I've been switched to the 5 GHz band, and my wife's laptop is not seemingly having the problem.

Maybe there's not enough information here for anyone to solve my problem. But could anyone fill me on on a likely explanation of what's going on here. A better understanding of how/why the Time Capsule router switched bands and the possible relation of that to me losing my internet connection....or not, is what I'm looking for. That information, or some suggested diagnostic steps perhaps, would help me sort this problem out.

Time Capsule-OTHER

Posted on Apr 8, 2014 12:02 AM

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Answer 1

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LaPastenague

Level 9

67,202 points

Apr 8, 2014 12:15 AM in response to willyjp

The TC is not changing.. it is dual band simultaneous router.. so it transmits the wifi on both bands at the same time.. and your computer is band jumping.. which it is also designed to do..

The theory is the Mac selects the best band with the best signal and speed. In your case your computer should swap back to 2.4ghz if the signal from the 5ghz drops.

What OS are you running on the laptop with problems? What is OS on the laptop with no problems?

If you have mavericks on both do a check in the same location you are having trouble. Use the diagnostics for wireless that is available in both computers.

You can do this when the wireless drops out and see what comes up.

http://support.apple.com/kb/HT5606

5ghz is preferred band because it is by nature faster.. 2.4ghz however has better signal.

You may find wireless is not as good on the older laptop.. although I also have a 2011 MBP which has excellent wireless.. or used to before I loaded that wretched Mavericks on it.

Sometimes the latest OS on older hardware is not actually a great idea.. but you need the measurements not just my bias.

A 3 year old TC is also getting into the unreliable stage.. and the latest firmware 7.6.4 is noted for having less than excellent wireless stability.. although the effect should be seen on both laptops if they are in the same position.. position here is critical.. think like a Realtor.. location location location. It is everything on wireless .. and much more so at 5ghz.

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Answer 2

willyjp Author

Level 1

22 points

Apr 8, 2014 1:05 AM in response to LaPastenague

Both MBPs are fully updated (10.9.2) and firmware up to date. Today this happened when both MBPs were operating right next to each other in the same room. Mine lost connection and hers was ok.

Thank you for the tip about the Wireless Diagnostics! Was not aware of the presence of that. Amazing the things that you can find with that "Option" key!!

Ran the wireless diagnostics and it found no present problem but in the conclusion it did make the comment that my environment had a lot of "electronic noise." ?!?

Not sure what that involves. We do have a cordelss phone system operating on 5.8 GHz. No microwave was operating at the time. We do live on a ridgetop on the fringes of a big city and there are a lot of antennas in these "heights" though none within 2 miles of our location. We do also have an ADT Alarm System Pulse Z-wave router plugged into the Time Capsule via Ethernet cable. But Z-wave operates at 900 MHz, so I would think it would be less of a "noise" problem than the cordless phone. But 2.4 GHz should, I would think, be nicely right in between. The Z-wave router is only a month old and this problem has been around for several months.

The diagnostic report suggested operating on 5 GHz because of the "noise" it apparently detected, though I'd think with my phone system 2.4 GHz would be better??

I will re-run the diagnostics and let them run in the background, as the application suggested, to see if I can pick up an intermittent problem.

If I make further pertinent findings, I'll repost here. Nothing I hate more than open-ended problems posted in a support forum. Many times I've wished people would have checked back in and posted what they found or what they did that worked (or didn't). So I will post further if I make any discoveries pertinent to this problem. Thanks for your help!

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Answer 3

Apr 8, 2014 5:10 PM in response to willyjp

Yes, keep us up to date.

Let me suggest if you haven't you do a wireless scan. And keep that open.

Then do a scan ..

Do it on both computers when they are sitting together and look at the RSSI and Noise figures on both for whatever wireless you are connecting to.

The diagnostic report suggested operating on 5 GHz because of the "noise" it apparently detected, though I'd think with my phone system 2.4 GHz would be better??

That would seem the obvious thing but the second laptop is not affected.. so I am thinking this is much more likely to be flakey drivers or just older hardware starting to show its age.

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Answer 4

willyjp Author

Level 1

22 points

Apr 9, 2014 4:23 PM in response to LaPastenague

I will most definitely award you a "solved" for that last suggestion. Here's how that worked: Not only was I unaware of the Wireless Diagnostics (which you clued me in to with your first answer) but I was totally unaware of the Utilities part of it until your second post. And the Utilities allowed me to see my problem.

I had run the Diagnostics, with report several times and only found "noise" as a problem. But the third time I ran it, it said my wireless router was suffering interference from another wireless transmitter nearby. That made me scratch my head at first. I have an Airport Express (very new) as an extender for my 3rd Gen. Time Capsule router, but it is set up correctly in "Extend" mode.

But when I ran the network scanner. lo and behold, there's my ADT Pulse Router (which is cabled to the Time Capsule via Ethernet connector) on Channel 6, as was the 2.4 GHz band of my my Home Network set up on the Time Capsule.

The ADT Pulse system was just installed about 6 weeks ago, and that's probably when this problem first appeared. The installer tech assured me: "This is just a 900 MHz router ("Z-Wave") for the wireless alarm sensors and it won't interfere with your Wi-Fi router." They said the Ethernet connection was so the Pulse Security system could access the internet and ADT's server. Beside communicating w. the sensors, the Pulse router also communicates with the main alarm panel, and I assumed that was also via 900 MHz wireless. But it turns out the thing is broadcasting on 2.4 GHz as well!! I'm not sure about this, but it may be using that wi-fi frequency to communicate w. the main panel. In any case, it was conflicting on Channel 6 w. the 2.4 GHz band of my Time Capsule I'm pretty sure.

So, using the recommended channels determined by the Utility Wireless Scanner, I reset my Home Network to use the optimum 2.4 GHz channel recommended and left the ADT router on channel 6. So far it seem to have solved my problem. And that probably explains why my network was switching to 5 GHz to try to avoid the interference.

One thing I noticed: Using the Airport Utility, it allows me to open Wireless Options and choose the channel for the Time Capsule, both main and guest network for both 2.4 & 5 GHz. But the Airport Express (set in Extend mode) does NOT offer channel selection at all. It appears that the main and guest network 2.4 GHz channels changed on the Extender in response to my main router new selection (at least they match now), but the 5 GHz channel did NOT change. So the Main and Extender Routes are using different channels for 5 GHz. Is the Extender router's channel supposed to auto set to match the main router if in Extended mode? Does it matter if the same network name/band has different channels between the Main Router and the Extended Router on 5 GHz??? If the Extender router doesn't follow the Main channel setting, how is one supposed to select it's channels? The "Wireless Options" dialog is just MISSING the channel selection part for the Airport Express Extender.

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Answer 5

Apr 9, 2014 6:40 PM in response to willyjp

Thanks for really excellent reply.. Diagnostics and wireless scans can show so much info.. and yes, you pick up things you didn't know existed.

If the TC was set to auto channels it should have swapped itself.. but I have discovered it is less than reliable.

But the Airport Express (set in Extend mode) does NOT offer channel selection at all.

Correct, it must connect and to do that it has to be on the same channel.

You cannot repeat on a different channel.

but the 5 GHz channel did NOT change. So the Main and Extender Routes are using different channels for 5 GHz.

Again correct.. You have extended on 2.4ghz not on 5ghz..

So you now have an interesting situation where the express is talking to your computer on 5ghz and sending those packets back to the TC on 2.4ghz. And that is what is happening.. what is more you might think this would make it faster because it should then be able to duplex.. ie to send and receive at the same time.. and here you would be wrong.. it cannot do that.

If your TC and AE happened to connect on 5ghz then that channel would be identical.

And the 2.4ghz would be different.

Here is where the older v5 utility stands out.. here is my network. This utility allows me to see all the connections simultaneously by opening each unit in a separate page..

Open it out as it shows a lot of info.. the units on each side are wireless extending from the AEgen3 which is creating the wireless network. so it is the main base. The AEgen5 on left links at 2.4ghz and the TCgen4 on the right links at 5ghz... I can force them to link in v5 utility if I set a separate name for 5ghz but it still does some odd things.

Once the link is established.. it then must set the 5ghz to not interfere.. so correctly will have them at different channels.

Here is the result as shown in the advanced page..

You can go back to the main summary pages and get the MAC addresses and see how everything is connected.. My computer is connected to the TCgen4 so it also shows in there.

And from the scan via wireless diagnostics I can see all the different units.

And if I look at the v6 utility. Then I see the same as you.. no abiltiy to set channels even for the unused band.

Just to show what the AE doing extend is like.

Whereas the AEgen3 has the channels set by me.

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Answer 6

Apr 9, 2014 6:48 PM in response to LaPastenague

Here is where things now start to get scary..

I just moved the AEgen5 to link to the 5ghz wireless instead of 2.4ghz.. instead of connecting to the AEgen3 it did something even I did not expect.. it linked to the TCgen4.

So I am also confused as this is not supposed to happen..

Actually it has inverted the naming of the bands..

Fun isn't it!!

I think I will get Bob to look at this as this is even beyond me.

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Answer 7

willyjp Author

Level 1

22 points

Apr 9, 2014 11:05 PM in response to LaPastenague

Very interesting, if a bit overwhelming for a novice at this stuff! I actually have the old Airport Utility 5.6...downloaded it some time ago (2 years?)....but now it won't run: "You can't us A... U... v. 5.6 with this version of OS X" or words to that effect when I try to start it. I do recall that it was MUCH more user friendly for anyone who wanted to be able to "open the hood" and get a sense of what was going on. I suppose v 6 is more in line with what Apple wants the Mac to be, but it sure isn't as easy to understand in terms of what is actually going on and what you're doing.

You allude to having the router on auto channel selection. I assume that's done in the channel line by selecting "automatic" instead of a number. When I open wireless options, this is what I see:

So, do you suggest that I should put the channel selection of both bands (of the Main router...I understand I can't set the Extended router) on "automatic?" I had manually set it on channel 6 quite some time ago. That was in response to the advice of Apple telephone tech support who was helping me deal with a problem of recognizing my Time Capsule's Time Machine drive after I had changed my computer's name (long story, but I inherited this 15" MBP from my wife who found the 13" much more comfortable for her to use and carry around). Anyway, after following all the intstructions (I thought) for changing my computer's name, I was having trouble getting Time Machine to work again on the Time Capsule's drive.

In the course of telephone tech support (which was sucessful in getting my problem fixed), the tech went through my wireless settings with me and had me take it off auto and set a fixed channel (6). He never said anything about changing it back when we were done, and frankly, until now, I had forgotten about that. If it had been on "automatic", this problem with the ADT Alarm System's router would probably never have come up. I think it's interesting that the ADT router got set on ch. 6 also! It seems to be camped on ch. 6 and that may be a fixed setting.

Sadly, ADT's gear is a "black box" to their users and that's the way they want it, so I have NO IDEA how to look into that router to see, let alone change its settings. Thankfully, the wireless diagnostic utility can see it just fine and tell what it's doing. But there's no access to settings, etc. that I know of. Of course the ADT Techs who installed it knew how to do that, but they give the user no advice, instruction or manual. Just plug in your "black box" and verify for you that, "it works!" (don't bother with the fact that you've set it on the same channel as my wi-fi!!).

Airport Utility can't see it except as a client with an IP address. But thankfully the wireless utility sees it like any other 2.4 GHz wireless router. It is made by NetGear. I should probably try to get a model # off it and research it to see if I can find a manual or a software utitily that can see inside it.

Anyway, thanks for all the help. I went ahead and set my Main router wireless to automatic channel selection so we'll see how that works. If for some reason that was a bad idea, let me know.

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Answer 8

Apr 10, 2014 12:06 AM in response to willyjp

I went ahead and set my Main router wireless to automatic channel selection so we'll see how that works. If for some reason that was a bad idea, let me know.

That is great.. but if you put it back to manual just select a different channel.. the main non-overlapping channels being 1, 6, 11 and generally it is best to use those to allow as much space as possible.. check with the wireless diagnostics to see what channel the automatic is using.

"You can't us A... U... v. 5.6 with this version of OS X" or words to that effect when I try to start it.

You can use it.. at least up to Mountain Lion.. I find it great to have both able to run.

How to load 5.6 into later Lion & ML

1. Download 5.6 for Lion.

http://support.apple.com/kb/DL1482

Click to open the dmg but do not attempt to install the pkg.. it won't work anyway.

Leave the package open on the desktop so you can see the file. AirportUtility56.pkg

2. Download and install unpkg.

http://www.timdoug.com/unpkg/

Run unpkg on the desktop.. If your Mac refuses to run the software, because it wasn’t downloaded from the Apple store, go to security in preferences and allow other software to work.. this is limitation of trade methinks. You can set back later if you like.

Now drag the AirPortUtility56.pkg file over to unpkg.. and it will create a new directory of the same name on the desktop.. in finder, open the new directory, drill down.. applications, utilities .. there lo and behold is Airport utility 5.6 .. drag it to your main utilities directory or just run it from current location.

You cannot uninstall version 6 (now 6.3 if you updated) so don't try.. and you cannot or should not run them both at the same time.. although I have had no problems when doing so.

There are even methods for putting it into Mavericks but it doesn't work as well so that is a real stop gap.

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