pub/sub content sharing for mobile networks format
We present Figaro, a content discovery solution for mobile environments. Our main focus is on urban networks, in which high densities of users coexist in relatively narrow, circumscribed areas reached by an infrastructure (e.g., bus stops integrating an AP). Figaro networks are overlay networks that operate according to the publish/subscribe (pub/sub) paradigm, featuring two main types of nodes: Agents and Brokers. Agents produce and consume the content, while it is the Brokers' task to let demands and offers meet. Agents are mobile (possibly handheld) devices, while Brokers are middle-end devices, integrated in the infrastructure and interconnected via a reliable (typically wired) backbone. When they discover a Broker, Agents can register with it declaring the services or contents (files, items of information...) they are willing to share with other Agents. Once the registration is complete, Agents can ask the Broker for the services they need. The Broker maintains a content-based routing table and queries it to answer such requests. The set of Agents exchanging services through a Broker is called colony. In a pure overlay fashion, colonies do not necessarily correspond to a set of nearby Agents. Although many works have dealt pub/sub in mobile networks, only few of them take into account the presence of an infrastructure and the opportunities it implies. With respect to them, our work includes novel protocol entities and addresses additional security and reputation issues. In particular, we describe our reference scenario and the behavior of Figaro in such conditions. Then, we show how this behavior can be improved, increasing the hit ratio and providing resiliency to misbehaving nodes.
overlay networks infomobility content delivery publish/subscribe protocol