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Lecture

Control Networks: MAC Protocol

In course

ME-427: Networked control systems

This course offers an introduction to control systems using communication networks for interfacing sensors, actuators, controllers, and processes. Challenges due to network non-idealities and opportunities offered by communication will be analyzed. ...

Description

This lecture covers the Medium Access Control (MAC) protocol in control networks, focusing on packet collisions, Ethernet CSMA/CD, CAN bus with CSMA/Arbitration Message Priority, and Token-passing bus. The instructor explains the reasons for collisions, the operation of different MAC protocols, and their pros and cons in terms of delay, packet loss, and efficiency.

Instructor

Giancarlo Ferrari Trecate

Official source

Ontological neighbourhood

Computer engineering

Computer networks: Local area networks

Related concepts (32)

Carrier-sense multiple access with collision detection

Carrier-sense multiple access with collision detection (CSMA/CD) is a medium access control (MAC) method used most notably in early Ethernet technology for local area networking. It uses carrier-sensing to defer transmissions until no other stations are transmitting. This is used in combination with collision detection in which a transmitting station detects collisions by sensing transmissions from other stations while it is transmitting a frame.

Medium access control

In IEEE 802 LAN/MAN standards, the medium access control (MAC, also called media access control) sublayer is the layer that controls the hardware responsible for interaction with the wired, optical or wireless transmission medium. The MAC sublayer and the logical link control (LLC) sublayer together make up the data link layer. The LLC provides flow control and multiplexing for the logical link (i.e. EtherType, 802.1Q VLAN tag etc), while the MAC provides flow control and multiplexing for the transmission medium.

Collision domain

A collision domain is a network segment connected by a shared medium or through repeaters where simultaneous data transmissions collide with one another. The collision domain applies particularly in wireless networks, but also affected early versions of Ethernet. A network collision occurs when more than one device attempts to send a packet on a network segment at the same time. Members of a collision domain may be involved in collisions with one another. Devices outside the collision domain do not have collisions with those inside.

Packet loss

Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is either caused by errors in data transmission, typically across wireless networks, or network congestion. Packet loss is measured as a percentage of packets lost with respect to packets sent. The Transmission Control Protocol (TCP) detects packet loss and performs retransmissions to ensure reliable messaging.

Ethernet

Ethernet (ˈiːθərnɛt ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, and longer link distances, but retains much backward compatibility. Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring, FDDI and ARCNET.

Related lectures (30)

Networked Control Systems

Explores networked control systems, covering delays, collisions, MAC protocols, and network architectures.

Networked Control Systems: Basics and Performance Analysis

Covers the basics of control networks, linear matrix inequalities, and networked control systems.

Mobile Networks: MAC Protocols

Explores MAC protocols, CDMA, ALOHA efficiency, and CSMA/CA in mobile networks.

Linear Matrix Inequalities: Control Networks

Explores Linear Matrix Inequalities in networked control systems and analyzes control networks' basics and performance.

Wireless MAC Protocols: CSMA and Aloha