The timely and efficient cooperative distribution of a streamlined content in a communication network is a key feature for many applications and services. One of the unsolved problems is the assignment of transmission rates to nodes given the constraints imposed by the topology, so that all nodes receive the stream with the minimal global use of resources. This paper addresses the problem exploiting the notion of eigenvector centrality. It shows that the problem can be solved efficiently in a distributed way if every node is aware of the full network topology and that in certain cases only local information on the network graph is sufficient.

Distributing live streaming in Wireless Community Networks (WCNs) is a service with a high added value; however, cloud-based streaming, as commonly used in the Internet, does not fit well the architecture of WCNs, which often have restricted access to the Internet. Modern WCNs, instead, can have a good internal connectivity with high bandwidth. A P2P approach is thus well matched for streaming in WCNs. This paper presents experimental results obtained with PeerStreamer running on top of Community-Lab, a test-bed realized by the CONFINE EU Project for the experimentation of novel protocols in community networks. The experiments highlight relevant differences between a WCN and the Internet, and we propose strategies that can beimplemented on all the peers or even only locally on the source to improve the streaming quality. These strategies are based on simple heuristics and can be activated dynamically when the streaming quality degrades below a given threshold.

Wireless Community Networks (WCNs) are bottom-up broadband networks empowering people with their on-line communication means. Too often, however, services tailored for their characteristics are missing, with the consequence that they have worse performance than what they could. We present here an adaptation of an Open Source P2P live streaming platform that works efficiently, and with good application-level quality, over WCNs. WCNs links are usually symmetric, or at least asymmetry is not by design as it is in ADSL, and a WCN topology is local and normally flat (contrary to the the global Internet), so that the P2P overlay used for video distribution can be adapted to the underlaying network characteristics. We exploit this observation to derive overlay building strategies that make use of cross-layer information to reduce the impact of the P2P streaming on the WCN while maintaining good application performance. We experiment with a real application in real WCN nodes, both in the Community-Lab provided by the CONFINE EU Project and within an emulation framework based on Mininet, where we can build larger topologies and interact more efficiently with the mesh underlay, which is unfortunately not accessible in Community-Lab. The results show that, with the overlay building strategies proposed, the P2P streaming applications can reduce the load on the WCN to about one half, also equalizing the load on links. At the same time the delivery rate and delay of video chunks are practically unaffected.

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