
132 Communication Architectures for SoC
FIGURE 4.2
Allocation fairness. Cars attempting to leave a parking lot through a single
exit. If fair local arbitration occurs at each intersection, the cars in the leftmost
rows must wait much longer than the cars in the rightmost rows to exit.
on. Hence, it can be understood that, in addition to traffic class segregation,
fairness within a given class is another requirement to QoS provisioning.
4.2.1 Traffic Class Segregation in Space
A natural way to guarantee that essential traffic is delivered according to the
required QoS is to make sure that high-priority traffic never contends with
lower-priority traffic for any