  The treatment of mobile and simultaneous critical urban events requires
effective actions by the appropriate authorities. Additionally it implies
communication challenges in the speed and accuracy of their occurrence by the
entities, as well as dealing with the dynamics and speed in these environments.
Cooperative solutions with shared resources that address these challenges
become a real option in helping to handle these events. This paper presents an
evaluation of dynamic monitoring and collaborative dissemination supported by
vehicular groups. It aims to analyze the impact of multiple mobile and fixed
events in an urban environment on information propagation, considering barriers
imposed by the events and the environment. Differently from other studies in
the literature, this work takes into account both fixed and mobile events, as
well as simultaneous events. NS3 results show that the evaluated system
monitored at least 87% and 51.5% of the time for mobile and fixed events
respectively, and delivered information over 77% and 50% of the time for those
events, with average delay remains close to 0.3s in most scenarios. The results
also reveal that a more continuous monitoring of the mobile events is highly
dependent on the orientation of the vehicles. The main contribution of this
work consists of the performance analysis of both fixed and mobile simultaneous
events to support studies on how moving events impact on the dissemination and
delivery of real-time data, and thus encouraging the development of new data
dissemination protocols for VANETs.
