The emulator does not provide virtual hardware for Wi-Fi if you use API 24 or earlier. From the Android Developers website:
When using an AVD with API level 25 or higher, the emulator provides a simulated Wi-Fi access point ("AndroidWifi"), and Android automatically connects to it.
You can disable Wi-Fi in the emulator by running the emulator with the command-line parameter -feature -Wifi.
https://developer.android.com/studio/run/emulator.html#wi-fi
What's not supported
The Android Emulator doesn't include virtual hardware for the following:
- Bluetooth
- NFC
- SD card insert/eject
- Device-attached headphones
- USB
The watch emulator for Android Wear doesn't support the Overview (Recent Apps) button, D-pad, and fingerprint sensor.
(read more at https://developer.android.com/studio/run/emulator.html#about)
https://developer.android.com/studio/run/emulator.html#wi-fi