AppleTV Failure

[DanSandbergUCONN]

Hi All - I recently purchased a new MacBook pro retina and the AppleTV unit as well. I want to use AppleTV to mirror my MacBook. I was able to get the desktop to show up on my TV but the picture is frozen. Sometimes the TV screen turns black and doesn't show anything. Either way, after a few minutes, the MacBook disconnects from mirroring and the AppleTV reverts to its regular display (i.e. list of movies or whatever screen was up before mirroring started).

I called Apple and was told this was the result of interference. Note that when I open the dropdown menu for the wireless, the RSSI for my router is -50 to -75 (I was told least interference was 0 and worst was -100). I tried moving my router into another room but this has not solved the problem. The router is a Belkin router. The AppleTV is sitting on top of my cable box, next to the TV, not inside an entertainment unit or anything. The router is currently next to my dresser. The computer, router, and AppleTV are all withing 8 feet of each other and still I can not get RSSI above -50.

So:
1) Is the problem really due to interference or could it be something else?

2) Other than moving the router and wireless devices, how can I improve the RSSI (interference)? I do not have any wireless telephones, baby monitors, or other devices that use wireless signals.


Thanks in advance.
-Dan

[DeltaMac]

Ah, you seem to have that backwards (or Apple told you incorrectly)
RSSI is Received Signal Strength Indication. A higher number (less negative in this case) indicates a relatively stronger signal, therefore a better signal, and not necessarily a measure of actual interference.
Less signal (more negative) will be more prone to interference, so you would look for the RSSI to be greater than -75 or -80 - and more than -50 is usually going to be a very strong wireless, with little interference.

Does your wireless card "see" other wireless networks, in addition to the one that you connect to? Always a good plan to assure that YOUR router is not transmitting on the same channel used by any other router that your wireless card can see. Set your router for a minimum of 3 channels separation (not always possible), or at least on a channel that is used by the weakest networks that show in your own system network list.
I mention that, because my own airport card can see up to 25 other wireless networks, depending on the time of day. Most are too weak to connect successfully(even if I knew a password), so I choose the channel with the weakest "other" signals. Mine uses channel 9, which is not a normal default - another reason to use it, as most users never change the router channel from the default. A good, "clear" channel will be up to you to determine.

[DanSandbergUCONN]

Thanks for the help and explaining RSSI, Delta.

First, my wireless card picks up at least 10 other routers (I'm in an apartment complex, sometimes I pick up many more).

Second, I thought that the "Auto Select" setting (Default setting for 'channel' on Belkin router) scanned the channels to select the lowest RSSI but maybe that isnt true?

Anyway, there appear to be 2 frequencies - one 2.4GHz and one at 5GHz - which is what I expected. The 2.4 GHz has channels {1-11} and the 5GHz has channels {36, 40, 44, 48, 49, 149, 153, 157, 151, and 165}. Simple math indicates 99 possible combinations. I tried all possibilities for either frequency with the other frequency set to "Auto Select". From there I tried about 30 different pairs of channels out of the 99 possibilities.

In all cases, the change in RSSI was about 10 points different. The least negative value was -43 and the most negative value was -51. (Note if I go into the next room the signal is around -75 and I never have trouble accessing the internet or loading webpages, etc.)

The lowest setting was channel 5 for 2.4GHz and channel 36 for 5GHz. However, checking RSSI multiple times (by repeatedly opening the dropdown menu for the wireless with the option key pressed), the values fluctuate from -40 to -60. With the channels set, I turned on apple TV. The sound streams to my TV with little break. The picture, however, updates once every minute at best.

SO... obviously a freeze-frame of my computer screen updated every minute onto the TV is not wireless mirroring. I'm not sure how best to troubleshoot from here. Is a signal strength of -43 really that bad? Is there a way to stabilize the signal, which is fluctuating to signals as low as -60? Would a new router solve the problem? I suppose the router with the longest distance range would correspond to the strongest signal?

[trevor]

Dan,

If your signal fluctuates between -40 and -60, then the signal is strong. What hasn't been determined yet, though, is what channels the other wireless networks in your building are using. For that information, try something like iStumbler: http://www.istumbler.net/

When you can see what channels other networks are using, stay as far away from them as possible, especially for the networks that have a strong signal where you're working.

As a very general rule of thumb, not always correct in specific circumstances, the 5GHz channels will have less interference and transmit farther distances. But I don't recall if the latest AppleTV uses 5GHz or not--you might be limited to 2.4GHz for AppleTV. Or not. Apple's specs for the device don't mention explicitly, although they do mention 802.11n.

Trevor

[trevor]

Here's a review on Anandtech that discusses the AppleTV's reception over WiFi. You may find it interesting:

Apple TV 3 (2012) Short Review - 1080p and better WiFi

Trevor

[DeltaMac]

Try searching for "fix slow AppleTV streaming", and you'll get to a variety of possibilities.
one example is to simply try restarting the AppleTV.
Another is that some users are affected by the use of one of the free DNS servers, such as Google, or OpenDNS. If you use one of those, you could try deleting those, to return to your system defaults - and, that fixes it for some folks, others have no effect.
As a test, try temporarily turning OFF security on your wireless router.
Apple support article?
http://support.apple.com/kb/TS3623
http://support.apple.com/kb/HT1595
http://support.apple.com/kb/TS4215

[DanSandbergUCONN]

Thank you Trevor and Delta. I'll review this information and report back.

Edit: Okay, iStumbler says I'm on channel 36 and when I change the 5GHz signal to anything else it says I'm on channel 0. iStumbler is also recognizing another router, belkin.6a4, which is on the same channel as my 2.4GHz frequency, channel 5. When I change my 2.4GHz frequency channel, belkin.6a4's channel changes in iStumbler to the same channel. Interestingly I can not access the belkin.6a4 wireless router with my router's password. However, they seem to be one-in-the-same. Could my belkin router be broadcasting two networks at different frequencies with different names? Could this be the issue? Especially if I'm committed to using the 2.4GHz signal with AppleTV but logged onto the 5GHz network on my macbook? Though, the AppleTV connected to my router, Gaussian, which seems to be the 5GHz frequency.... This will require some more messing around.

[trevor]

Quote: Originally Posted by DanSandbergUCONN Especially if I'm committed to using the 2.4GHz signal with AppleTV

The Anandtech article is a little confusing on the subject, but I think that it says that the Apple TV 3 uses 5 GHz.

Quote: Originally Posted by Anandtech The maximum PHY rate and presence of 2.4 and 5 GHz band support is unchanged from Apple TV 2.

Quote: Originally Posted by Anandtech You'll notice that antenna 2 on the Apple TV 3 only gets used (at least for transmit) on the 5.2 GHz band - channels 36 to 48. This is the small band below the DFS-enabled 5 GHz band (52-140). Remember that the "best" 5 GHz channels in the USA are the traditional 802.11a channels 149-165 since you can run with higher power. BCM4330 supports optional external antenna diversity - it's entirely possible this is also being used on the receive side.

Quote: Originally Posted by DanSandbergUCONN Could my belkin router be broadcasting two networks at different frequencies with different names?

Exactly what model is your Belkin router?

Trevor

[anthlover]

As you said things are close any chance of going wired? Thats blood simple. Even if it is not practical from a neatness perspective you should do it as a test. You can easily get 25 or 50 foot cable to run things neatly later.

** Yes you can have a lot of interference and other issues. It would help if can also tell us what which Belkin router you have. Is it Simultaneous, Dual band.

Just for the record. In open room 5ghz is much faster and much less subject to interference from other devices. On the other hand passing through walls and such greatly limits the range of 5ghz.

[DanSandbergUCONN]

Quote: Originally Posted by trevor Exactly what model is your Belkin router?

The model number is F9K1102v1. Thanks for the help.

Quote: Originally Posted by anthlover As you said things are close any chance of going wired?

Good suggestion. I'll give this a shot. I suppose if it doesn't work we have a different problem than interference?

Quote: Originally Posted by anthlover ** Yes you can have a lot of interference and other issues. It would help if can also tell us what which Belkin router you have. Is it Simultaneous, Dual band.

It is this model - http://www.helpowl.com/p/Belkin/F9K1...102v1%20manual

[anthlover]

I would go wired for testing... I see its a Dual band. I would use the 5ghz radio when you do go wireless.

http://www.belkin.com/us/p/P-F9K1102

Monoprice is a great place for cables
http://www.monoprice.com/products/se...B=10232#Search

[DanSandbergUCONN]

Quote: Originally Posted by anthlover I would go wired for testing... I see its a Dual band. I would use the 5ghz radio when you do go wireless. http://www.belkin.com/us/p/P-F9K1102 Monoprice is a great place for cables http://www.monoprice.com/products/se...B=10232#Search

Quick question - when I go wired I would turn off the Wi-Fi on the computer and the AppleTV and plug both into the ports on the router, right?

[anthlover]

Test 1:
If you want to eliminate variables you can turn off wifi on Macbook and Plug it and the Apple TV into the Router. Do not think you need to turn wifi off on the Apple TV, it should use the wired connection. You can do so if you like.

Test 2
Only Apple TV Wired

If both Test 1 and 2 are successful you need to figure out the wireless problem.


I would go 5ghz with small area and clean line of site.

Good Luck.

[DanSandbergUCONN]

Update: I started with test 2 because I did not have the right USB cable to connect the MacBook to the router (and of course the new MacBook has no ethernet port) but test 2 works! So if the appleTV is wired to the router, we're in business. Now, if I disconnect the ethernet, even though the router and appleTV are side-by-side, I either get no picture or a frozen picture. If I check the wireless signal on the appleTV when the ethernet is disconnected, it is maxed out. I think I'm running on the 5GHz channel but I don't see an option for this in the appleTV settings.

[anthlover]

Great so we know its a network problem.

** The apple TV settings for wireless have to do with what network you select SSID A vs B, etc.

The control for what wireless network's exist are contained within your router. You can choose what frequencies 2.4, 5ghz N or Non N, etc. I am not familiar with your particular router's set up. On some routers besides choosing the frequencies to broadcast you can choose whether 2.4 and 5ghz use the same SSID.

For your situation it sounds like 5ghz Only or Separate names would be better so you can select the 5ghz from your Apple TV.

Sounds like from this note below that names are separate for the 5ghz appended to whatever you called your network.

http://www.belkin.com/us/support-article?rnId=8306

If you have lost track of the names you created and settings you can always reset. If you messed around with the settings alot you might want to return them to their default values.

[DanSandbergUCONN]

UPDATE: Interesting development, anth... When I am on the 5GHz signal, the picture either does not come through or is frozen BUT the 2.4GHz signal transmits smoothly! I guess the appleTV prefers 2.4GHz? Even when the appleTV is wired, the picture has a minor delay. Once a movie is playing, it isn't noticable, but if someone wanted to use a large flat screen as a monitor this would not be ideal.

My personal review of this product: Its a great idea but it needs work. I would've preferred to pocket the $100 and use the money for an extra long HDMI cable.

[anthlover]

The issues are with Airplay, not the regular Apple TV to TV or with playing back Applications video from the Apple TV itself.

As far as I know 5ghz should work and work better. I believe you proved the issue is network, since wired worked pretty well.

Airplay is also dependent on a feature in the intel chipset.

There is a third party alternative. Do not think it will solve the network issue but it might be interesting to try.

??? What exactly are you Air playing. There may be better ways to achieve your goals. Apple TVs can pull media straight off your computer without resorting to mirroring.