In this paper, we focus on the study of the Distributed Coordination Function (DCF) protocol, which is based on the basic CSMA/CA multiple access scheme, provided with a second RTS/CTS mechanism to avoid collision effects. However, the major problem that causes the loss of frames is the internal or external signals’ influences, which disturb the transmitted signal, and thus noise errors occur. This leads us to suggest a new analysis of the Saturation Throughput (ST) for IEEE 802.11b DCF protocol. We consider the Packet Fragmentation Mechanism (PFM), Data Fragment Retransmission, without Renewing the Channel Reservation Mechanism (DFR/RCRM) and the distinction between control frames lost due to noise and control frames lost due to collisions. This work provides an analytical model of 3D Markov chain. It is closer to the real IEEE 802.11b DCF protocol’s functioning and calculates the ST in a very precise manner. We determined the appropriate ST for both cases where the DFR/RCRM was and was not employed. The results indicate that a wireless network installed in a noisy environment utilizing DFR/RCRM performs better than one using a simple IEEE 802.11b DCF.