Rogers and Fido: same network?

[Fish n Chips]

I have heard people in the industry mentioned that Fido and Rogers share the same cellular network.

Does it mean that I can use a GSM cell phone locked to Rogers, have a FIDO sim inserted to that phone and use it like I have an unlocked phone?

Has anyone tried that?

[dr_jared88]

Nope. Won't work. Same company yet different. Just like you can't use a Futureshop gift card at Best Buy.

[CRXguy]

No, phone still has to be unlocked.