|Thanks for your prompt reply.|
I think you are correct. About a year ago I configured a spare WiFi Router as a AP for switch use, but it need to be wired to a LAN port on the primary router.
As far as the phone goes I want to wire an external wireless USB adapter direct to the phone's RJ45 input port and wire the phone RJ45 output port to the desktop NIC port. I found the USB Type A Female to Type A Female cable and USB over RJ45 Ethernet Adapter is available. The supplier of this Telephony VOIP Host PBX system is designed to have the phone wired between the network and the client computer. I figured if I can wire the external USB adapter direct to the phone then this is how the signal will be tranmitted to the phone.
The telephony system supplier (Fonality) won't guarantee, but their tech. seems to believe this will work. The phone won't know any different whether or not the received signal is direct from the primary network router of via the external USB wireless adapter. If I discover signal degradation is too significant then I can go to the expense of wiring the CAT cable.
It might be worth a try to avoid the cost of wiring a CAT line to my third floor office. Any other suggestions will be much appreaciated.