Like vehicles like pedestrians, in an interconnected world

We present some scenarios where a group of people walking around and linked together by a common intent can take advantage by communicating with each other by means of their smartphones and tablets implementing an ad-hoc network. We show the results of a study for extending to walking pedestrians of an optimal broadcast for platoon of vehicles traveling on a road. The extension has the scope of porting the original broadcast from a mono-dimensional space to a bi-dimensional one. The pedestrians can walk in open spaces and are not constrained to move along roads or walkways. We can consider that each person brings its own smartphone or tablet. The current models of these devices offer enough computational power to run both a communication mechanism and an overlying application. We started from an optimal and lightweight P2P communication system for vehicles. Smartphones and tablets are devices fully equipped to implement such a broadcast service by means of GPS receivers and WiFi capabilities. We show several examples and scenarios to proof the impossibility of extending the optimal broadcast from one to two dimensions. The mono-dimensional case takes strong advantages from the underlying geometry and its key concepts became unusable in a bi-dimensional case.