The localization performance of a wireless sensor network localization system is highly related to the rate at which it can transmit ranging signals and measurements. The underlying media access control (MAC) protocol and application level ranging and communication protocol of the Cricket Location-Support System (CLS) is analyzed to identify bottlenecks. Unnecessary delays in the existing MAC layer, which is based on carrier sense multiple access with collision avoidance (CSMA/CA), are identified and removed. This greatly improves the rate at which radio frequency (RF) packets can be transmitted. To further improve localization performance, a time division multiple access (TDMA) protocol for an active architecture is proposed to replace the randomized schedule used by CLS to transmit ranging signals. Experiments show that the new protocols produce higher sampling rates than the original CLS communication protocols.