Cellular, Wi-Fi, Bluetooth, NFC and GNSS

Build a clear model of the radios, bands, protocols and permissions behind phone connectivity.

Core ideas

Use these points to build an accurate technical model before changing the device.

• Carrier compatibility depends on supported bands, regional model and certification.
• Wi-Fi and Bluetooth versions describe capabilities, but antenna design and software affect real range.
• NFC and GNSS features depend on hardware, region, app access and service support.

Decision rule

When a connection fails, isolate device, network, accessory, account and regional requirements one at a time.

Apply it on your phone

Record the device facts, source and expected result. Make one reversible change, observe the outcome, and keep the evidence needed to undo it.