U-Verse loses signal nightly

Is this a wireless box?  If so try moving the AP that is connected to your AT&T gateway.  Move it up, down, as far from the gateway as possible, etc. until you can mitigate the problem.  I installed a 15ft. patch cord on my AP and moved it away as far as I could.  It now sits on top of one of the speakers for my stereo.  Problem is no longer there after that.

I do have a wireless box. I watch programming from 10PM to 1AM. I begin to lose the signal after mid-night. So for 2 hours there are no issues with the programming signal.

The gateway and the attached wireless box (AP)?? is located in a closet in a separate room. If the distance between the gateway and the attached wireless box is critical, then why do I enjoy 2+ hours of uninterrupted signal?

How many bars show on the wireless box while the signal is "good" and when you loose signal (3 marginal, 4-5 good)?

Do you possibly have any equipment that may be turning on during that time that could cause interference?

Are you attached to a UPS?

I'll take these in reverse order,

No. Not attached to UPS

No other equipment in use.

Last evening, the U-verse Lost signal started after 11:30PM. First, the screen freezes, then the Lost Signal Message appears. Before and during the freezes I have 5 bars. After a period of inactivity, the program eventually reappears. Last evening I only experienced 5 outages.

How many TV Receivers do you have?  You should have at least two, since the one you're having issues with is wireless.  Does the other (or any of the others if you have more) have this same issue?  Do the lights on the U-verse Gateway change significantly when this is going on?

I'm thinking that you're having an issue with the connection between your Gateway and the AT&T Network.

I have 5 receivers, 2 of which are Wi-Fi receivers. The Wi-Fi receivers are on the same floor with the gateway. The gateway is located in a communication panel in a clothes closet. The Wi-Fi device is located in the closet outside of the communication panel. Both TV's on the same floor connected by Wi-Fi regularly lose the signal. Another TV on the same floor is direct connected (No Wi-Fi). The lost signal screen occurs on the 3 direct connected TV, however at a less frequency than the Wi-Fi connected TV's.

Just to clarify your setup and some questions...

• You have 5 receivers. 
• Two wireless, three wired.
• One wired is the dvr (or course) using, which, ethernet or a coax connection?
• The other two wired must be ethernet connected to two of the yellow ethernet ports on your gateway.
• What are the model numbers of your wireless receivers, gateway, and WAP (wireless access point, little black box also ethernet connected to the gateway).  If the dvr was ethernet connected then the WAP used the one remaining ethernet port on the gateway.  If the dvr is coax connected then you should still have one remaining free ethernet port.
• The gateway is located inside a "communication panel in a clothes closet".
• The WAP is outside the communication panel but still in the clothes closet?

So you do have problems with both wired and wireless receivers, less less frequently for the wired.  When the problem occurs on one of the wireless receivers have you checked a wired receiver to see if it has problems at the same time?  And have you checked the gateway to see if it's got any red lights showing?

How much ventilation does the gateway have in that communication panel?  Is there any reason the temperature might increase in there during your problem times?

I believe some older equipment has problems supporting two wireless receivers.  That's why I asked for the model numbers for the wireless receivers, gateway, and WAP.

If you are using a coax connection from the gateway to the dvr you might want to consider replacing that with an ethernet connection.  It plugs into the network port on your dvr.

Thinking out loud...

My only problem with these suggestions is they are general and I am not sure why any of this would cause problems only after a certain time of day.  Usually things like that are from some kind of interference.  Maybe you don't have anything that may cause the interference that doesn't mean it couldn't be from some external source.  Such things are hard to pin down.

Even the interference theory is suspect if you say you have similar problems with your wired receivers.  All this then points back to the gateway which is the common factor in the setup.  I doubt reboot or factory reset would fix this but you might as well give it a shot.  Ventilation bothers me though.  I wonder if the gateway gets warmer when under load.

Here's a list of AT&T equipment in my home;

First Floor

Living Room  VIP2250  Coax connected  Infrequent outages during the day and evening

Bedroom 1    VIP1200  Coax connected  This is a spare bedroom and the TV viewing is minimal.

Second Floor 

Bedroom 2    ISB7005  Wi-Fi        This is the TV that I experience outages after 11PM

Bedroom 3    ISB7005  Wi-Fi        This TV experiences outages early in the evening (Before 11PM)

Loft               VIP1200   Coax connected

Wi-Fi             VEN401AT  Connected by ethernet to Router

Bedroom 3 has a clothes closet with the home electronics center in the back. The cabinet is installed between the wall studs with an access door. The access door is ajar to allow the ethernet wire to connect to the Wi-Fi sending unit. The Wi-Fi unit is resting on a home security cabinet that is mounted on the wall away from the hanging clothes To access the center a rack of clothes must be removed for access. I wasn't going to empty the closet to get to the router.  The Wi-Fi device is in the closet, however it is not inside the electronics center.

I think it's clear that the issue is with lost communication between the TV devices and the source of the signal.  It is clear that it is not solely an issue with the wireless communication.  What is still not clear is where the issue lies (or if there is more than one issue present).  Let me throw more questions out there:

• When watching TV, do you normally watch it live as it is shown, without rewinding, pausing or other "trick play" DVR features?  If not, do you note these issues more/less/the same when "caught up to live" as when "catching up" or watching a recording?
• Do these issues happen more or less when watching a recording?
• Do you normally watch HD or SD channels/content?
• Since you cannot see the gateway easily, can you access it via http://192.168.1.254/ and look at the table of statistics (Sync rates, attenuation, SNR and error counts) on the Broadband page?  Could you take a screen snip and post?  Also looking for the "uptime" or "last boot time" value.

You didn't list the gateway model.  And now you got me a little confused.

The VIP2250 is the your dvr.  Ok you can connect it to your gateway (which has only one coax rf connector) with coax but it is usually not recommended (use ethernet instead).  But if you actually are coax connected to the dvr just how can you say the two VIP1200's are coax connected?  I hope you aren't trying to use a RF splitter for all those connections.  VIP1200 is a pretty old receiver model by the way.

As for the wireless receivers, you say you have a VEN401AT WAP.   That may be your problem whether problems occur at a fixed time range or not.  That's one of the older models and it's problematic when using it to handle two wireless receivers.  You really should have VAP2500 WAP.  Since you didn't specify the gateway model, if it's one of the older models (which I'm guessing it is considering the equipment you are listing), I believe it too needs upgrading to properly handle two wireless receivers.  You're ok with the ISB7005 wireless receivers however.  They're pretty current and reliable (I have one of those).

One final thought.  Given your description of your gateway placement "buried" in a wall at the back of a cloths closet, I am still concerned about ventilation and in this case, for that matter, being a fire hazard.  IMO the gateway should really not be considered an "out of sight, out of mind" device (is that why you didn't list the model number?).  Sometimes you need to see its status lights or reboot it, and maybe in your case, replace it.  And they don't put all those ventilation holes in the box for nothing.  Maybe I'm overly paranoid, but given that location together with clothes in the same closet I would really be worried about a fire.