In a contention-based MAC system, what are the consequences of adding more nodes to the network?

In a contention-based Medium Access Control (MAC) system, the way nodes share the communication medium is crucial to understanding the impact of adding more nodes to the network. As more nodes are introduced, the likelihood of multiple devices attempting to transmit data simultaneously increases. This leads to an uptick in collisions—instances where two or more nodes transmit at the same time and their signals interfere with each other.

When collisions occur, the involved nodes must back off and attempt to resend their data after a random time interval, which not only delays the transmission of the collided packets but can also lead to further collisions as more nodes compete for the same bandwidth. As a result, adding more nodes creates a chaotic environment where the medium becomes congested, amplifying the frequency of these collisions. Therefore, it is clear that in a contention-based MAC system, increasing the number of nodes directly correlates with an increase in collisions.

While improving data transfer speeds, changing power requirements, or decreasing latency may be plausible in different networking scenarios, they do not result from simply adding more nodes to a contention-based MAC environment. Instead, they may lead to detrimental effects that make the network less efficient and more prone to issues.