to sense that the medium is idle when a low power packet follows a high power one the above solution prevents legacy devices from accessing the medium during the cfp other methods that may be used to assure this include using actual packet concatenation as proposed in the second proposal above or using a signal transmitted by a certain device e g the manager during the whole cfp independent of the actual data packets notice that when all legacy devices use packets with priority lower than 7 a cfp may be created in a much simpler way in that case using priority 7 by all enhanced devices will ensure that no lower priority packet i e no legacy device packet will gain access to the medium the enhanced devices need to interpret the polling messages of the manager and gain access to the medium accordingly using the cfp_ifg to prevent other non enhanced devices to sense an end of the packet and to try and gain access this might require the enhanced devices to use a new access mechanism other than the currently implemented cs mechanism during the cfp outside of the cfp within cp the standard csma cd mechanism can be used to allow all devices legacy as well as enhanced to access the medium cfp 39 s can occur periodically quasi periodically or non periodically notice that some delay in the beginning of a cfp may occur due to the medium being busy because of a transmission of a packet from a legacy device which began within the cp and u201c slipped u201d to the cfp range this can cause the beginning of the cfp to slip which should be taken into account enhanced devices using the cp may be designed.