Unlocked phone from Rogers to Bell

I'm on a family plan with rogers and my cell phone just died. My dad is planning to go to Bell (so the phone internet tv... blah is all packaged) when the contract is up so I can't get a decent phone from rogers without signing up and dragging out the contract. I was thinking of getting an unlocked phone and then just switching the SIM cards when we switch to Bell. Will this work? and if so does anyone know what frequencies the phone needs to be able to use inorder for it to make this switch. I'm kinda confused as to whether there will be a problem going from rogers GSM to CDMA (or whatever) at bell.
thank for your help

you wont be able to use the rogers phone on the bell network... Rogers uses GSM and TDMA, Bell uses CDMA..so no sim cards...best bet is to go with a promo bell has on for a new phone.

Also Bell does not allow foreign ESN's on their network. So you may not allow unlocked CDMA phones on their network. Even if they are fully compatible. If you want to have the choice of using an unlocked phone try either fido or Rogers.