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Contention-free (Token-based) Medium Access Protocols (MAC)

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• Contention-free protocols
  • Contention-free medium access protocols:

    Network access is regulated by a special frame: Token frame         A node is only allowed to transmit a data frame (message) when: The node has received the token frame

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• Token-based protocols
  • There are 2 standards for token-based (contention-free) protocols:

    Token ring (IEEE 802.5) Token bus (IEEE 802.4)