I have an extra Blackberry and an extra sim card with normal data plan. I want to use it for BBM & Email, as I know BB is required to join BIS in order to do so.
Can I use my sim card and join some other official BIS provider (non mobile company), so I can use BBM and Email with my BB?
BB (with normal data plan) -> Blackberry Internet Service -> Internet??
I don't think so. Joining BIS requires a BB data plan from your carrier. I've never seen a third party BIS provider. There are some BES providers but I think you still need the BB data plan.