This document proposes a MAC protocol for wireless access over TV white spaces that improves throughput and reduces collisions. It introduces (i) an architecture and beaconing mechanism to enable the MAC, which is an evolution of 802.11, (ii) an algorithm for assigning radios and clients, and (iii) demonstrates gains of 30-76% higher throughput and up to 80% lower collisions compared to Wi-Fi in simulations and a prototype implementation.