How can I add a RBS50 satellite to my new RBE773 router?

Deploying more than one WiFi network in a single home is possible, but has some definite "considerations".

• Both routers must be connected using an Ethernet cable to their WAN port.  If there is not in-wall wiring, this will result in having two WiFi routers next to each other where the ISP device is located.
• If both systems are set up in 'router mode', then devices connected to one router will be invisible to devices connected to the other router.
  This may not be a major concern to some users.  It depends on what devices are connected to the network and how they are expected to interact.
  The obvious solution is to configure the older WiFi5 system in 'access point' (AP) mode.
• There is a potential for interference.  This can be mitigated a bit by using different radio channels for the two systems.
• The biggest issue is that no matter how they are configured, they will remain two separate WiFi systems.  This will not affect devices which remain in one place.  Mobile devices will probably not roam seamlessly between one system and the other.  (This was the Achilles Heel of the previous method for expanding WiFi coverage:  WiFi "extenders".)
  Even if both systems are set to exactly the same WiFi credentials (SSID/password), a mobile device may stubbornly stick to one system even as the WiFi signal decreases, rather than switch automatically to a stronger signal from the other WiFi system.
  "Honey. Why is my FaceTime so slow?"  (sigh) "Did you remember to turn WiFi off and back on when you came downstairs?"

So, the plan might be to:

• Try to separate the RBR50 from the RBE773 by running an Ethernet cable to get it at least 20-30 ft. away.
• Cover the parts of the house where mobile devices are most likely to be used with the RBE773 system.
• Use the RBR50 system to cover mostly non-mobile devices, or perhaps placed in windows to extend coverage outside.