Generally, this depends on the coding format of streaming. While there exist various coding formats which assure the best image quality along with high level of compression such as H264, other formats would compress the streaming at a lower rate. Accordingly, different formats demand a different minimum amount of bandwidth. Roughly, the minimum bandwidth which is needed for streaming is 25 Mbps for SD channels and 30 Mbit for HD ones.
Average required bandwidth
25 Megabits per second - Recommended for SD quality.
30 Megabits per second - Recommended for HD quality.
50 Megabits per second - Recommended for Ultra HD quality.