ARRIS SBG6900-AC dropping WiFi signal

[Bob5861]

I have an ARRIS SBG6900-AC Cable modem/router on my home network.  It is personally-owned, not leased from Comcast.  It CONSTANTLY drops the WiFi network.  4-5 times a day, for 15-60 seconds, then comes back all by itself.  The blue lights on the router remain lit, telling it has a strong WiFi signal.  I am on the other side of a small condo and lose the signal.  But, my wife sits right next to the router and she loses it, too.

I've caslled ARRIS support and they say the signal the router is receiving from the provider (Comcast) is weak.  The four inbound chaqnnels vary from 42.0dBmV to 43.5dBmV.  ARRIS says it should be at least 46.  But, Comcast says anything above 33 is acceptable.  Comcast has been out and done all it can to improve the signal.  Removing noise on the line.  Replacing cables, wall plates, any unnecessary equipment.  The problem still persists.

I've tried moving the router to different locations.  No effect.  I've put Netgear WiFi extenders throughout the house.  Those do nothing.  When I connect to any of the extenders I get a WiFi connection, but no Internet.  So, that doesn't help.  Also, the extenders each create a different SSID.  And, cell phones don't automatically switch from one SSID to another as you move around.  So, they latch onto one SSID and then the signal gets weak as you move around.

I need some suggestions on what to do about this.  My wife and I work from home so, losing WiFi throughout the day means dropping a phone call... or a Skype call.  Unacceptable.

The ARRIS SBG9600-AC was a highly recommended cable modem/router.  The strongest signal I could afford.  Comcast has had me change channels multiple times.  No success. 

Is there a solution I can find for what I have?  Do I need to go to a mesh router setup where the SSID would be the same throughout my home?  I've read mesh routers can be a problem when the signals overlap too much.

Help! 

[EG]

For a test, does a computer hardwired directly to the router / gateway device with an ethernet cable have the same problem ?

[Bob5861]

I don't understand the reply.  I'm losing the WiFi signal and the question is to see if it does the same thing if I'm directly wired in?  How are the two related?  Directly-wired is not WiFi, and vice versa.

[EG]

We are trying to narrow it down to a WiFi only (WiFi opens up a ton of more problems) or a general connectivity problem with the Comcast coax cable system which would affect both. Makes perfect sense. You didn't answer the question BTW...

[Bob5861]

I've been directly connected to he router all day today and have not seen a single drop yet.  When on WiFi I would have seen at least 3-4 by now.  It appears to be a WiFi only issue.

[EG]

Some tips for improving WiFi performance;

http://corporate.comcast.com/comcast-voices/10-ways-you-might-be-killing-your-home-wi-fi-signal

http://forums.xfinity.com/t5/Your-Home-Network/Improve-Your-Wireless-Gateway-Home-Network/td-p/26276...

https://www.xfinity.com/support/articles/improve-your-wireless-home-network

There are other options. Google for WiFi repeaters / range extenders, WiFi mesh systems / pods, powerline ethernet adapters, MoCA adapters. Good luck !

[Bob5861]

I've tried moving the router around.  I reboot it weekly.  I have installed Netgear WiFi extenders and, for some reason, they do not connect to the Internet.  They extend the WiFi, but no Intenet.  Plus, when you move from room to room your mobile device does not change its connection.  It remains connected to the first signal it found.  I've had Comcast out and they have removed every source of noise they could find.  The issue there is that... Arris says the signal from the provider is weak, but Comcast says it's within their specs.  Their specs are just lower than the router manufacturer.  I asked about mesh routers in my original post.  Would they help?  

So, I've tried everything everyone says to try.  I get "finger-pointing" between the provider and the router manufacturer.  They both say its the other's fault.  Meanwhile I still get my WiFi signal dropping 5-10 times a day.

[EG]

They say that a mesh network has better performance than WiFi extenders;

https://www.google.com/search?q=mesh+network+vs+wifi+extender&rlz=1C1SQJL_enUS782US782&oq=mesh+netwo...