What is collision avoidance techniques?
Collision avoidance techniques are used in telecommunications and computer networks to avoid resource conflicts. These techniques attempt to eliminate situations where multiple nodes are accessing the same resource. This ensures that every node in a network can transmit a signal without colliding with other traffic on the network.
Some of the most commonly used collision avoidance methods include:
- Carrier recognition programs
- Pre-planning of time windows
- Randomized access times
– Exponentielles Zurücksetzen nach der Collision detection
Network collision avoidance occurs primarily in Carrier Sense Multiple Access (CSMA) networks. This is based on the principle that nodes that are ready to transmit data must listen to the channel for a period of time to determine whether other nodes are also transmitting on the wireless channel. A node can only start transmission when a channel appears to be idle, otherwise transmissions are deferred. Collision avoidance improves CSMA performance because multiple nodes cannot be transmitted at the same time. The likelihood of a collision is reduced by using a random shortened binary exponential back-off time.
Collision avoidance divides the wireless channels evenly among the sending nodes within the collision domain. It is complemented by the exchange of requests to send a package. Nodes within transmitters and receivers are warned not to transmit during the main transmissions.
A popular avoidance scheme has a sender-initiated four-way handshake, the transmission of a data packet and the acknowledgment of its receipt being preceded by a request to send and an enable to send. The nodes that overhear these packets delay their channel access to avoid collisions.