What is the demand priority media access method?

Demand priority is the new Ethernet media access method that will probably replace the popular but older CSMA/CD method. Demand priority access has the following characteristics:

• Used with 100 Mbps Ethernet
• Requires a 'smart' hub that controls access to the network
• Stations must request permission from the hub before they can transmit
• Transmissions are sent through hub and are not broadcast to all other stations
• Stations can transmit and receive at the same time
• Transmits on all four wire-pairs of twisted pair wire (i.e., can use Category 3 cable)
• Transmissions can be prioritized (e.g., time sensitive traffic such as video is given priority)