This article describes about coupons.For the emerging class of social network and information sharing applications,coupons form an idea to define, evaluate, and
implement algorithms.To overcome highly variable Internet access through adaptive localized interaction,coupons allow users to opportunistically interact and share data through a wireless medium.To encourage participation,coupons allow the incorporation of an incentive scheme to make the system usable.Evolution of our society into a nearly constant access to the Internet takes place in two directions-evolution of devices and
evolution of network access.Users can now operate through a range of options through novel devices like Personal Digital Assistants (PDAs).So,the focus is about being able to share content, either through the Internet or through direct interaction with different users.So,the real focus lies in the formation of social networking communities in wireless environments and,this arises from the desire for data sharing through opportunistic contact.Opportunistic contact is defined as the ability to interact and communicate with people who are near the same geographical location.Major two challenges include-firstly,The network must thus maintain connectivity as best as possible even though nodes are moving and disconnecting frequently.Secondly,nodes are expected to participate in relaying even though they have no incentive.So,finally,the goal of this article to investigate this evolving area of research.

The report pdf can be downloaded from:
http://mediafire?1nkkk59pq8zdk2l