Wireless technologies have permeated a significant number of devices over the years. On the other hand, Medium Access Control (MAC) protocols strive to deal with an increasing number of contending nodes on crowded frequency bands. This work presents an efficient medium access control resolution protocol. The proposed protocol, termed Collision Resolution Protocol (CRP), uses pulse/tone signaling that works in both Collision Detection (CD) and Non-Collision Detection (NCD) environments. Given n>1 contending nodes, CRP selects a single transmitting node in 16n and 40n time slots, respectively, for the CD and the NCD scenarios, with probability of at least 1-2-1.5n. Furthermore, CRP does not require an exact number, or estimation, of the contending nodes. Extensive simulations on... the OMNeT++ shows that, for n = 256 and considering CD-capability, CRP successfully grants channel access in 0.03% of the time required by the IEEE 802.11 standard while improving the number of transmissions per second in 100%. In addition, CRP provides fair resource allocation and reduced channel access latency.