Traditional medium access control (MAC) protocols utilize temporal mechanisms such as access probability or backoff interval adaptation for contention resolution. They typically take the set of competing nodes as a given, and address the problem of adapting each node's channel access behavior to the given channel contention level. This Is a temporal approach for contention resolution, which aims to separate transmissions from different nodes In time to achieve successful transmissions. We explore an alternative approach for wireless networks-named "spatial backoff" - that adapts the "space" occupied by the transmissions. Each transmission In a wireless network competes for a certain space. By adapting the space occupied by transmissions, the set of "locally" competing nodes, and thus, the channel contention level, can be adjusted to reach a suitable level. There are different ways to realize spatial backoff. In this paper, we propose a dynamic spatial backoff algorithm using the Joint control of carrier sense threshold and transmission rate. Our results suggest that spatial backoff can lead to a substantial gain In channel utilization.