A wireless local or metropolitan area network comprising: a plurality of stations (11,12) configured to transmit data therebetween using a media access layer, hereinafter referred to as MAC, each of said stations having a respective MAC address associated therewith; and a policing station configured to detect intrusions into the wireless network by monitoring transmissions among said plurality of stations to detect at least one of: (a) frame check sequence, hereinafter referred to as FCS, errors from a MAC address and generate an intrusion alert based upon the detected number of FCS errors for the MAC address exceeding a threshold; (b) failed attempts to authenticate MAC addresses and generate an intrusion alert based upon the detected number exceeding a threshold of failed attempts to authenticate a MAC address; (c) service set IDs associated with the wireless network and generate an intrusion alert based upon one of the detected service set IDs being different than the service set ID of the wireless network; (d) an illegal network allocation vector, hereinafter referred to as NAV, value, the NAV value indicating a time duration reserved for transmitting the data generated from request to send and clear to send packets transmitted among said plurality of stations prior to transmitting data forming and generate an intrusion alert based upon the detected illegal NAV value; (e) contention-free mode operation by said plurality of stations outside of contention-free periods, hereinafter referred to as CFPs and generate an intrusion alert based upon the detected contention mode operation during a CFP; and (f) contention mode operation during a CFP and generate an intrusion alert based upon the detected contention-free mode operation outside a CFP; wherein said plurality of stations are configured to transmit data over at least one channel; wherein said policing station is further configured to detect transmissions over the at least one channel not originating from one of the plurality of stations and generate an intrusion alert based thereon; and wherein said policing station is further configured to transmit an intrusion alert to at least one of said plurality of stations. a plurality of stations (11,12) configured to transmit data therebetween using a media access layer, hereinafter referred to as MAC, each of said stations having a respective MAC address associated therewith; and a policing station configured to detect intrusions into the wireless network by monitoring transmissions among said plurality of stations to detect at least one of: (a) frame check sequence, hereinafter referred to as FCS, errors from a MAC address and generate an intrusion alert based upon the detected number of FCS errors for the MAC address exceeding a threshold; (b) failed attempts to authenticate MAC addresses and generate an intrusion alert based upon the detected number exceeding a threshold of failed attempts to authenticate a MAC address; (c) service set IDs associated with the wireless network and generate an intrusion alert based upon one of the detected service set IDs being different than the service set ID of the wireless network; (d) an illegal network allocation vector, hereinafter referred to as NAV, value, the NAV value indicating a time duration reserved for transmitting the data generated from request to send and clear to send packets transmitted among said plurality of stations prior to transmitting data forming and generate an intrusion alert based upon the detected illegal NAV value; (e) contention-free mode operation by said plurality of stations outside of contention-free periods, hereinafter referred to as CFPs and generate an intrusion alert based upon the detected contention mode operation during a CFP; and (f) contention mode operation during a CFP and generate an intrusion alert based upon the detected contention-free mode operation outside a CFP; (a) frame check sequence, hereinafter referred to as FCS, errors from a MAC address and generate an intrusion alert based upon the detected number of FCS errors for the MAC address exceeding a threshold; (b) failed attempts to authenticate MAC addresses and generate an intrusion alert based upon the detected number exceeding a threshold of failed attempts to authenticate a MAC address; (c) service set IDs associated with the wireless network and generate an intrusion alert based upon one of the detected service set IDs being different than the service set ID of the wireless network; (d) an illegal network allocation vector, hereinafter referred to as NAV, value, the NAV value indicating a time duration reserved for transmitting the data generated from request to send and clear to send packets transmitted among said plurality of stations prior to transmitting data forming and generate an intrusion alert based upon the detected illegal NAV value; (e) contention-free mode operation by said plurality of stations outside of contention-free periods, hereinafter referred to as CFPs and generate an intrusion alert based upon the detected contention mode operation during a CFP; and (f) contention mode operation during a CFP and generate an intrusion alert based upon the detected contention-free mode operation outside a CFP; wherein said plurality of stations are configured to transmit data over at least one channel; wherein said policing station is further configured to detect transmissions over the at least one channel not originating from one of the plurality of stations and generate an intrusion alert based thereon; and wherein said policing station is further configured to transmit an intrusion alert to at least one of said plurality of stations.