AbstractÐIn a multihop wireless network, each node has a transmission radius and is able to send a message to all of its neighbors that are located within the radius. In a broadcasting task, a source node sends the same message to all the nodes in the network. In this paper, we propose to significantly reduce or eliminate the communication overhead of a broadcasting task by applying the concept of localized dominating sets. Their maintenance does not require any communication overhead in addition to maintaining positions of neighboring nodes. Retransmissions by only internal nodes in a dominating set is sufficient for reliable broadcasting. Existing dominating sets are improved by using node degrees instead of their ids as primary keys. We also propose to eliminate neighbors that already received the message and rebroadcast only if the list of neighbors that might need the message is nonempty. A retransmission after negative acknowledgements scheme is also described. The important features of proposed algorithms are their reliability (reaching all nodes in the absence of message collisions), significant rebroadcast savings, and their localized and parameterless behavior. The reduction in communication overhead for broadcasting task is measured experimentally. Dominating sets based broadcasting, enhanced by neighbor elimination scheme and highest degree key, provides reliable broadcast with SQ percent of node retransmissions (on random unit graphs with 100 nodes) for all average degrees d. Critical d is around 4, with RV percent for Q, RH percent for d ! IH, and PH percent for d ! PS. The proposed methods are better than existing ones in all considered aspects: reliability, rebroadcast savings, and maintenance communication overhead. In particular, the cluster structure is inefficient for broadcasting because of considerable communication overhead for maintaining the structure and is also inferior in terms of rebroadcast savings.
Convexity estimators are commonly used in the analysis of shape. In this paper we define and evaluate a new easily computable measure of convexity for polygons. Let È be an arbitrary polygon. If È ½´È «µ denotes the perimeter in the sense of Ð ½ metrics of the polygon obtained by the rotation of È by angle « with the origin as the center of the applied rotation, and if È ¾´Ê´È «µµ is the Euclidean perimeter of the minimal rectangle Ê´È «µ having the edges parallel to coordinate axes which includes such a rotated polygon È , then we show that ´È µ defined ascan be used as an estimate for the convexity of È . Several desirable properties of ´È µ are proved, as well.
In a multihop wireless network, each node has a transmission radius and is able to send a message to one of its neighbors (one-to-one) or all of its neighbors (oneto-all) that are located within the radius. In a broadcasting task, a source node sends the same message to all the nodes in the network. Some existing solutions apply rebroadcasting from each clusterhead or border node in a clustered structure. In this paper, we propose to reduce the communication overhead of broadcasting algorithm by applying the concept of internal nodes. The maintenance of internal nodes requires much less communication overhead than the maintenance of cluster structure of nodes. In one-to-all broadcasting, only internal nodes forward the message, while in the one-toone case messages are forwarded on the edges that connect two internal nodes, and on edges that connect each non-internal node with its closest internal node. Existing notions of internal nodes are improved by using node degrees instead of their IDs (which are used only as secondary keys) in internal node decisions. Highest node degrees are also proposed for reducing the number of clusterheads and border nodes in a clustering algorithm. Further savings are obtained if GPS and the concept of planar subgraphs are used for one-to-one networks. In case of one-to-all model, no re-broadcast is needed if all neighbors already received the message. The important features of proposed algorithms are their reliability (reaching all nodes in the absence of message collisions), significant savings in the rebroadcasting, and their localized and parameterless behavior. The reduction in communication overhead for broadcasting task, with respect to existing methods, is measured experimentally. 0-7695-
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.