Bell customers on the LTE Advanced network can enjoy blazing-fast download speeds up to 750 Mbps (expected average speeds of 25-220 Mbps).
When outside the LTE Advanced coverage areas, you'll have access to the LTE network. When outside of the LTE coverage area, you'll have access to the 4G HSPA+ network. The Bell network never falls back to 2G.
Theoretical peak speeds may vary by region.