telecommunication Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of ...

, a shared medium is a medium or channel of information transfer that serves more than one user at the same time. In order for most channels to function correctly, no more than one user can be transmitting at a time, so a

channel access method In telecommunications and computer networks, a channel access method or multiple access method allows more than two terminals connected to the same transmission medium to transmit over it and to share its capacity. Examples of shared physical ...

must always be in effect. In circuit switching, each user typically gets a fixed share of the channel capacity. A multiplexing scheme divides up the capacity of the medium. Common multiplexing schemes include time-division multiplexing and

frequency-division multiplexing In telecommunications, frequency-division multiplexing (FDM) is a technique by which the total bandwidth (signal processing), bandwidth available in a communication channel, communication medium is divided into a series of non-overlapping freque ...

. Channel access methods for circuit switching include time-division multiple access, frequency-division multiple access, etc. In

packet switching In telecommunications, packet switching is a method of grouping Data (computing), data into short messages in fixed format, i.e. ''network packet, packets,'' that are transmitted over a digital Telecommunications network, network. Packets consi ...

, the sharing is more dynamic — each user takes up little or none of the capacity when idle, and can utilize the entire capacity if transmitting while all other users are idle. Channel access methods for packet switching include carrier-sense multiple access, token passing, etc.

Examples

* DOCSIS * GPON * 10BASE5

References

Multiplexing {{Telecomm-stub