The 8865 phones are designed to be used with CUCM or (with 3PCC firmware) with a third-party PBX. You can probably get the 8865 to connect to the wireless, but it will need to register to something.
Here is a link to connecting the 8861 model to wireless. The steps for the 8865 are the same:
Connect the Cisco IP Phone 8861 to a Wireless Network
Maren