Single VOIP Wifi phone into my PBX

Good day,

we currently have NOTHING related to VoIP in our company. We have a
standard Nortel PBX with ATAs for Faxes and analog phones.

Currently, we have a 900mhz wireless phone connected to our PBX using
an ATA that will soon go to trash. Since most of our plant is WiFi
enabled (many APs in the plant), i would like to replace this 900mhz
phone by a VoIP Phone. Here is what i have and what i want.

[PBX]----ext 200---[ATA]----analog line----[Phone base] ))) (((
[900mhz Phone]

I would want ¨

[PBX]----ext 200---[ATA]---analog line---[VoIP Phone Base] ))) wifi
((( WiFi VoIP Phone

Most of what i see on the internet are VoIP PBXs or something that is
way too big for my little need.

The VoIP Phone base would have an IP Address, the WiFi Phone to and
would connect to the Phone Base using our WiFi Wireless network.

Dunno if im clear or not. Thank you