This document discusses improving quality of service parameters in wireless sensor networks using a reinvented FSMAC protocol. The FSMAC protocol first uses fuzzy logic to detect intrusions based on two new parameters: the number of times a node senses a free channel and the variation in channel sense periods. If an intrusion is detected, appropriate countermeasures are taken to reduce the effects of attacks. Simulations with 20 nodes show that the reinvented FSMAC protocol increases successful data transmission rates and network throughput.