An efficient and shortest path selection primary-segmented backup algorithm for real-time communication in multi-hop networks
S. Pandey, Rajneesh Kumar Pandey · 2013
The Development of high-speed networking has introduced opportunities for new applications such as real-time distributed computation, remote control systems, video conferencing, medical imaging, digital continuous media (audio and motion video), and scientific visualization. Several distributed real-time applications (e.g., medical imaging, video conferencing and air traffic control) demand hard guarantees on the message delivery latency and the recovery delay from component failures. As these generally demands cannot be met in old or traditional datagram services, special type of schemes have been proposed to provide timely as well as efficiently recovery for real-time communications in multihop or multi node networks. These schemes reserve additional network resources (spare resources) a priori along a backup channel that is disjoint with the primary.Such distributed real-time applications demand quality-of-service (QoS) guarantees on timeliness of message delivery and failure-recovery delay. These guarantees are agreed upon before setting up the communication channel and must be met even in the case of bursty network traffic, hardware failure (router and switch crashes, physical cable cuts, etc.), or software bugs. Applications using traditional best effort datagram services like IP experience varying delays due to varying queue sizes and packet drops at the routers. As we know that in distributed system all application required guarantees of the message delivery in short time along with shortest path. To deliver message from source to destination node, we have used a primary path.Since we know that the primary path is the shortest path and very advantageous too.But it can break down due to numerous reasons as any communication network is prone to faults due to hardware failure or software bugs.If the primary path fails then the data can be lost and as a result it will not reach its destination.In order to avoid such data loses we may use an alternative path known as end to end back up path to send or deliver data packets,but it may not be the shortest path.Coincidently if this alternate path also fails ,then there ie no other technique or path to send data from source to destination.Therefore it is essential to incorporate fault tolerance into QoS requirements for distributed real time multimedia communications.Such fault tolerance can be obtained by the use of segmented backup path. A Segmented back up path is the shortest path used to deliver a message from source to the destination in a mul-tihope network environment in which backup paths are provided for partial segments of the primary path rather than the entire primary path length.The only disadvantage with the segmented back up path is that it uses the already used nodes of the primary path. Establishment of backup paths saves the time required for reestablishing the channel in reactive methods. In this paper we are proposing an algorithm which will analyze the primary path, alternate path (end to end backup path) and segmented back up path. After analyzing these entire paths, the proposed algorithm will select a shortest path among all these paths and it will work for all cases.