애드혹 네트워크 환경과 관련된 성능 목적을 충족하는 라우팅 기술이 제공된다. 본 발명의 기술은 네트워크의 수명을 실질적으로 최대화시킨다. 본 발명의 일형태에 있어서, 분산 네트워크의 노드에 사용되는 패킷 라우팅 기술은 다음의 단계/동작을 포함한다. 패킷을 저장하기 위한 큐가 유지된다. 여기서, 하나 이상의 큐는 노드와 이웃 노드 사이에 존재하는 링크와 관련되고, 큐는 그와 관련된 높이를 갖는다. 그후, 이웃 노드에서의 큐의 높이에 기초하여 큐에 저장된 하나 이상의 패킷에 대한 루트를 결정하여 노드와 이웃 노드와 관련된 에너지 제한이 실질적으로 최대화되도록 한다. 분산 네트워크는 바람직하게 모바일 애드혹 네트워크이고 노드와 하나 이상의 이웃 노드는 무선 링크를 통해 통신한다.

Maximum lifetime routing in wireless ad hoc networks

Geographic convergecast using mobile sink in wireless sensor networks

DAR: An energy-balanced data-gathering scheme for wireless sensor networks

We propose two algorithms to form spanning trees in sensor networks. The first algorithm forms hierarchical clusters of spanning trees with a given root, the sink. All of the nodes in the sensor network are then classified iteratively as subroot, intermediateor leafnodes. At the end of this phase, the local spanning trees are formed, each having a unique subroot (clusterhead) node. The communication and data aggregation towards the sink by an ordinary node then is accomplished by sending data to the local subroot which routes data towards the sink. A modified version of the first algorithm is also provided which ensures that the obtained tree is a breadth-first search tree where a node can modify its parent to yield shorter distances to the root. Once the sub-spanning trees in the clusters are formed, a communication architecture such as a ring can be formed among the subroots. This hybrid architecture which provides co-existing spanning trees within clusters yields the necessary foundation for a two-level communication protocol in a sensor network as well as providing a structure for a higher level abstraction such as the i¾?synchronizer where communication between the clusters is performed using the ring similar to an i¾?synchronizer and the intra cluster communication is accomplished using the sub-spanning trees as in the βsynchronizers. We discuss the model along with the algorithms, compare them and comment on their performances.

/pdf/distributed-algorithms-to-form-cluster-based-spanning-trees-57nln7pb6h.pdf

Distributed Algorithms to Form Cluster Based Spanning Trees in Wireless Sensor Networks

A wireless sensor network (WSN) consists of hundreds or thousands of sensor nodes organized in an ad hoc manner to achieve a predefined goal Although WSNs have limitations in terms of memory and processors, the main constraint that makes WSNs different from traditional networks is the battery problem which limits the lifetime of a network Different approaches are proposed in the literature for improving the network lifetime, including data aggregation, energy efficient routing schemes, and MAC protocols Sink node mobility is also an effective approach for improving the network lifetime In this paper, we investigate controlled sink node mobility and present a set of algorithms for deciding where and when to move a sink node to improve network lifetime Moreover, we give a load-balanced topology construction algorithm as another component of our solution We did extensive simulation experiments to evaluate the performance of the components of our mobility scheme and to compare our solution with static case and random movement strategy The results show that our algorithms are effective in improving network lifetime and provide significantly better lifetime compared to static sink case and random movement strategy

https://journals.sagepub.com/doi/pdf/10.1155/2014/167508

Controlled Sink Mobility Algorithms for Wireless Sensor Networks

Spanning trees rooted at a sink node are often employed for data collection in sensor networks. The node's double task of sensing and forwarding traffic from other nodes results in energy depletion which is dependent on the constructed spanning tree. The approach taken in this paper is to extend the lifetime of a sensor network by judiciously recalculating the data collection tree to adjust it pro-actively before nodes fail due to total energy depletion. The proposed scheme attempts to make energy-critical nodes leaf nodes, or, as a last resort, to balance the traffic load handled by them. Additionally, an exponentially decaying threshold is used for adaptively characterizing nodes as critical. Simulations demonstrate significantly improved network lifetime but also point to the need to carefully set the thresholds for characterizing nodes as critical.

ENCAST: energy-critical node aware spanning tree for sensor networks

We consider the problem of extending the lifetime of wireless sensor networks (WSNs) where sensors report their data to a base station via multi-hop transmission. In-network data aggregation is introduced to reduce the traffic. The lifetime is optimized using a LP (linear programming) framework built on a multicommodity network flow model to which we introduce the concept of flow loss multiplier to express the impact of data aggregation over correlated data. To balance energy consumption across the network, data aggregation is performed only at the first hop (FH) transmission. Heuristics are proposed to obtain significant FH aggregation, accordingly prolonging system lifetime. Simulation results show that FH aggregation possesses characteristics that make it suitable under certain data collection applications/scenarios.

S. Zou

Papers

ENCAST: energy-critical node aware spanning tree for sensor networks

Extending sensor network lifetime via first hop data aggregation