Coordinating Crowd-Sourced Services

The growing ubiquity of smartphones and similar personal connected computational devices, each with a number of sensors, has created an opportunity for useful services based on crowd-sourced data. A busy professional could find a restaurant to go to for a quick lunch based on information available from smartphones of people already there having lunch, waiting to be seated, or even heading there, a government could conduct a census in real-time, or "sense" public opinion. Although the programming required for offering a new service of this sort can be significant if done from scratch, these applications have something in common: they use a similar pattern of coordinated communications between the various parties. This creates an opportunity to offer a set of coordination mechanisms as a platform to service designers, into which they can simply plug in their service specific code to offer a new service. This paper identifies the coordination mechanisms required for these crowd-sourced services as types of multi-origin communication. We present details of how these core mechanisms can be implemented using Actors, and introduce high-level programming constructs for launching a new service. Finally, we use examples to illustrate the implementation of services.