A Self-organized Clustering-based Overlay Network for Application Level Multicast

2009 ◽  
Vol 4 (2) ◽  
Author(s):  
Khaled Ragab ◽  
Akinori Yonezawa
Author(s):  
A. Sotiriou

The technical and ethical issues of these systems proved to be their weak point. Systems that have no central point of control and distribute functions among all users seem better fit for sharing and distributing content. A solution has been proposed in the form of distributed hashtables (DHTs). This article proposes an alternative architecture for content distribution based on a new DHT routing scheme. The proposed architecture is well structured and self-organized in such a way as to be fault-tolerant and highly efficient. It provides users with content distribution and discovery capabilities on top of an overlay network. The novelty of our proposed architecture lies in its routing table which is maintained by each node and is of constant size, as opposed to other algorithms that are proportional to the network’s size (usually O(logN)). All operations in our architecture are of O(logbN) steps (entry, publishing, and lookups) and degrade gracefully as up-to-date information of the routing table decreases due to numerous node failures.


Author(s):  
Khaled Ragab

Peer-to-Peer (P2P) file downloading and streaming applications have recently attracted a large number of users on the Internet. Currently, several P2P video streaming systems have been deployed to reduce the cost at server. They are classified into two categories live and on-demand streaming systems. The live streaming systems disseminate live video contents to all peers in real time. On the other hand, the on-demand video (VoD) streaming system enables peers to enjoy the flexibility of watching video. It realizes the goal of watch whatever you want, whenever you want. The current P2P-VoD systems cannot realize such goals efficiently. This chapter proposes a self-organized structured overlay network of peers to realize that goal and improve performance. Each peer is able to cache some video minutes associated with the current media being played. The proposed overlay network is organized into clusters. Each cluster contains peers with overlapped buffer windows where their playing points are located between lower and upper play point limits. When a peer in the cluster moves its play point within the limits, for example by performing a seek operation, it then can rapidly discover and fetch the required blocks for the playback buffer from peers in the same cluster. Clusters improve both discovery and fetch overheads. However, it needs cluster management overhead.


2004 ◽  
Vol 05 (03) ◽  
pp. 279-298 ◽  
Author(s):  
JUAN LI ◽  
SON VUONG

Peer-to-peer (P2P) computing offers many attractive features, such as self-organization, load-balancing, availability, fault tolerance, and anonymity. However, it also faces some serious challenges. In this paper, we propose an Efficient Clustered Super-Peer P2P architecture (ECSP) to overcome the scalability and efficiency problems of existing unstructured P2P system. With ECSP, peers are grouped into clusters according to their topological proximity, and super-peers are selected from regular peers to act as cluster leaders and service providers. These super-peers are also connected to each other, forming a backbone overlay network operating as a distinct, yet integrated, application. To maintain the dynamically adaptive overlay network and to manage the routing on it, we propose an application level broadcasting protocol: Efa. Applying only a small amount of information about the topology of a network, Efa is as simple as flooding, a conventional method used in unstructured P2P systems. By eliminating many duplicated messages, Efa is much more efficient and scalable than flooding, and furthermore, it is completely decentralized and self-organized. Our experimental results prove that ESCP architecture, combined with the super-peer backbone protocol, can generate impressive levels of performance and scalability.


2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.


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