  This article studies distributed event-triggered consensus over unreliable
communication channels. Communication is unreliable in the sense that the
broadcast channel from one agent to its neighbors can drop the event-triggered
packets of information, where the transmitting agent is unaware that the packet
was not received and the receiving agents have no knowledge of the transmitted
packet. Additionally, packets that successfully arrive at their destination may
suffer from time-varying communication delays. In this paper, we consider
directed graphs, and we also relax the consistency on the packet dropouts and
the delays. Relaxing consistency means that the delays and dropouts for a
packet broadcast by one agent can be different for each receiving node. We show
that even under this challenging scenario, agents can reach consensus
asymptotically while reducing transmissions of measurements based on the
proposed event-triggered consensus protocol. In addition, positive inter-event
times are obtained which guarantee that Zeno behavior does not occur.
