access request

With the request technique, a data station that is willing to transmit makes sure that the transmission medium is free, e.g. by listening to the bus before transmission starts with the Ethernet or by detecting a token with the Token Ring.

In the request technique, stations willing to send send a request for channel allocation to the control center. This request is then taken into account according to various criteria.

Since, depending on the protocol version, the total failure of a single station is not mandatory, decentralized techniques are preferred. They are also more in line with the idea underlying local area networks( LAN) of distributed processing of problems.