It would be useful to conduct a brief experiment that should take less than one hour:

• Temporarily locate the router or one satellite next to the exterior wall facing the outbuilding, preferably in a window.
• Temporarily locate the other satellite near the wall of the outbuilding facing the house, again preferably in a window.
  (The goal of this is to have the least WiFi-interfering building material in the radio path.)
• Turn on the satellite in the outbuilding and see if it gets a "Good" connection to the system.
  From page 11 of the user manual:
  

   

• If the result is a "Good" connection, then moving a satellite to the outbuilding or purchasing another satellite to place in the outbuilding will result in extending seamless WiFi.

  Background:  The default link between Orbi 350 units is a 5G WiFi signal (channel 157 in North America and channel 108 in the rest of the world.)  5G WiFi has tremendous capacity, but is affected by distance and building materials.  Netgear recommends placing the units close enough together to result in a "Good" WiFi connection (Blue  LED for three minutes).  The connection is strongest (and fastest) when the units are very close together.  Placing units close to each other, however, does not expand the area covered with strong WiFi very much.  As the units are placed farther and farther apart, the total coverage area expands, but the connection link suffers.  The "sweet spot" inside most houses is "around 30 ft." (10 meters).  Obviously units require electrical supply and thus are not likely to be placed in the middle of rooms, so people make a compromise that results in covering enough space with strong WiFi and still having a "Good" connection between units.  20 meters of open space (no walls. no furniture.) might still be close enough.

   

  If the experiment fails to produce a "Good" connection, the next step would be to consider alternatives.  Many users have found that a "wireless bridge" can connect systems across relatively short distances and not cost a lot.  I suggest a quick search for "wireless bridge" with retailers in your area.  (In the US, I start with Amazon or a Google search.)  For example, the UeeVii CPE450 sells for about $120US on Amazon.  The TP-Link CPE510 sells for $50US each and it takes two.)

  (I tend to look for products with hundreds of reviews and prefer major manufacturers such as TP-Link, Ubiquiti, etc. 

   

  Since these units are rated in terms of kilometers, they often can be placed inside both buildings and have the signal strength to pass through both building walls and still deliver adequate performance.

   

   

   

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