  The growing need for low-latency access to computing resources has motivated
the introduction of edge computing, where resources are strategically placed at
the access networks. Unfortunately, edge computing infrastructures like fogs
and cloudlets have limited scalability and may be prohibitively expensive to
install given the vast edge of the Internet. In this paper, we present
Opportunistic Edge Computing (OEC), a new computing paradigm that provides a
framework to create scalable infrastructures at the edge using end-user
contributed resources. One of the goals of OEC is to place resources where
there is high demand for them by incentivizing people to share their resources.
This paper defines the OEC paradigm and the involved stakeholders and puts
forward a management framework to build, manage and monitor scalable edge
infrastructures. It also highlights the key differences between the OEC
computing models and the existing computing models and shed the light on early
works on the topic. The paper also presents preliminary experimental results
that highlight the benefits and the limitations of OEC compared to the regular
cloud computing deployment and the Fog deployment. It finally summarizes key
research directions pertaining to resource management in OEC environments.
