  Event-triggered control has the potential to provide a similar performance
level as time-triggered (periodic) control while triggering events less
frequently. It therefore appears intuitive that it is also a viable approach
for distributed systems to save scarce shared network resources used for
inter-agent communication. While this motivation is commonly used also for
multi-agent systems, a theoretical analysis of the impact of network effects on
the performance of event- and time-triggered control for such distributed
systems is currently missing. With this paper, we contrast event- and
time-triggered control performance for a single-integrator consensus problem
under consideration of a shared communication medium. We therefore incorporate
transmission delays and packet loss in our analysis and compare the triggering
scheme performance under two simple medium access control protocols. We find
that network effects can degrade the performance of event-triggered control
beyond the performance level of time-triggered control for the same average
triggering rate if the network is used intensively. Moreover, the performance
advantage of event-triggered control shrinks with an increasing number of
agents and is even lost for sufficiently large networks in the considered
setup.
