topology control in wireless ad hoc and sensor networks pdf

... have discussed the potential advantages of using TC techniques in wireless ad hoc and sensor networks: reducing node energy consumption and reducing radio interference between nodes ... that ad hoc and sensor networks are used in different environments: typically, ad hoc networks are deployed in urban scenarios, where the presence of buildings, obstacles, and ... configuration reported in Figure 14.5. 172 LEVEL-BASED TOPOLOGY CONTROL master routing table is formed by joining entries from different RT i routing tables, and by adding one additional field to

Ngày tải lên: 14/08/2014, 14:20

... reducing energy consumption and/or increasing network capacity Introduction: 1/7 Trang 4Topology control: an informal definitionTopology control: the art of coordinating nodes’ decisions regarding ... Trang 3Istituto di Informatica e Telematica Motivations for topology control  Both energy and capacity are limited resources in ad hoc networks  In case of Wireless Sensor Networks (WSN), energy ... Motivation: the need for Topology Control (TC) in ad hoc networks – An ad hoc network model – Topology control: a taxonomy  Stationary networks – The critical transmitting range for connectivity

Ngày tải lên: 14/08/2014, 14:20

... power the minimum level such that the corresponding routing table contains all the nodes in the network  Setting the power to this minimum level achieves the three goals of: – maximizing network ... not known in advance (for instance, sensors spread from a moving vehicle) some distribution; which is the value of r which guarantees connectivity with high probability (w.h.p.)? Remark: In this ... 5Geometric Random Graphs GRG: a set of n points are distributed in a d-dimensional region R according to some distribution, and some property of the resulting node placement is investigated

Ngày tải lên: 14/08/2014, 14:20

... ratio between the minimum-power path in G’ and in G  In words, the power stretch factor is a measure of the increase in the Trang 9Power spanners (2) Ideal features of a routing graph: – Small ... energy-efficient way  Why use the routing graph G’ instead of G? – Because G’ is sparse, thus the task of finding routes between nodes is much easier than in the original graph Trang 8Power spanners ... the energy cost is minimum  Solving the WSRA problem remains NP-hard for two and three-dimensional networks [Blough et al.02a]  In [Blough et al.02a], it is proved that the additional energy

Ngày tải lên: 14/08/2014, 14:20

... information), the more energy savings can be achieved  However, information quality (and, thus, the energy savings) must be carefully traded off with the cost incurred for making the information available ... concept of broadcast stretch factor of a subgraph G’ of G can be defined  Also in this case, the goal is to find sparse broadcast spanners that can be computed in a distributed and localized ... advantage of topology control: reduce interferences, thus increasing network capacity  node degree = “measure” of expected interference (low is good)  So far, emphasis on reducing the logical

Ngày tải lên: 14/08/2014, 14:20

... destination in [0,1] 2 , and moves towards it along a straight line with velocity chosen at random in [v min ,v max] When it reaches the destination, it rests for a time t pause, then it starts moving ... it starts moving according to the same rule [, and velocity chosen at random in [v min ,v max] After a randomly chosen time, the node chooses a new direction and velocity in a disk centered around ... [WattenhoferZollinger04]  Basic idea (similar to KNeigh): – at the beginning, every node orders its neighbors (set of nodes in the maximum transmitting range) according to some criterion (e.g., link quality)

Ngày tải lên: 14/08/2014, 14:20

... circle  In realistic scenarios: radio coverage area influenced by many factors (obstacles, buildings, existing infrastructure, weather conditions, etc.), and it is hardly regular  Including too ... models Ad hoc network model used in this presentation is widely accepted, but it is a very idealized model of a real wireless network  Main limitation of this model: assumption that the radio ... Trang 3Non-homogeneous TC In case of non-homogeneous TC: more relevant effect of mobility is the message overhead needed to maintain the desired topology  Overhead depends on the frequency

Ngày tải lên: 14/08/2014, 14:20

... certain constraint (on the network lifetime, or on the QoS), and given a TC protocol, which is the optimal frequency for reconfiguration? o Preliminary step in this direction: the determination ... Trang 4TC in the protocol stack Where should TC be positioned in the protocol stack?  No clear answer in the literature Our view: Routing Layer MAC Layer TC Layer Trang 5TC and RoutingOne possible ... needs to be done to investigate the effect of mobility on TC: – Is mobility beneficial or detrimental? o On one hand, mobility increases message overhead o On the other hand, it balances the

Ngày tải lên: 14/08/2014, 14:20

... at the following URL: http://www.imc.pi.cnr.it/~santi  A survey paper on TC: P Santi, “Topology Control in Wireless Ad Hoc and Sensor Networks”, Tech Rep IITTR04/2003, Istituto di Informatica ... in the previous slide can lead to packets getting into infinite loops! 1mW 10mW Trang 5Tunneled CLUSTERPOW To avoid this, the packet is “tunneled” to its next hop using lower power levels, instead ... (to adjust the maximum transmit power and send broadcast messages) and per-packet TC (to send point-to-point messages) will be the best choice Trang 13 A bibliography on TC is available on-line

Ngày tải lên: 14/08/2014, 14:20

... throughput due to inherent fading properties of wireless channels Transport Layer in ad-hoc and sensor Trang 9Problems in Wireless Networks Leads to OOO packets Trang 10Problems in Wireless Networks ... HTTP response FIN ACK FIN ACK Connection Termination Client Server Transport Layer in ad-hoc and sensor Trang 5TCP MechanismsSliding Window Slow Start  Is triggered at the beginning of connection ... Communications Magazine. Transport Protocol for Ad-hoc Networks", in Proc of MobiHoc, 2003.  Nitin H Vaidya, “TCP for Wireless and Mobile Hosts”. TCP over Wireless Links”. Networks”. Trang

Ngày tải lên: 24/05/2016, 22:34

... 1Chapter 13Ad Hoc and Sensor Networks Trang 2 Table-driven Routing Protocols Source-initiated On-demand Routing  Hybrid Protocols  Wireless Sensor Networks  Flat Routing in Sensor Networks ... within a zone and propagating route error to the source Trang 32Wireless Sensor Networks Wireless sensor networks are a collection of hundreds or thousands of tiny disposable and low power sensor ... assignment of bandwidth. Trang 36Routing Issues in Sensor Networks In traditional wired networks each node is identified by a unique address, which is used for routing Sensor networks, being data

Ngày tải lên: 10/10/2016, 09:05

... theing qualit (QoS) demands of multimedia while system issues and ts al-lo and provisioning in wireless ad ho networks Sp , we study the problemofm network hedulingunderatime-varying hanneland ... and by also using stability of ψ hains, we present the rst method of hieving optimization tivelyina tralizedmanner inageneral wirelessMarko queueingnetwork, and opera-for derivingstability and ... knowledge,by using of ψ Markohains,wepresent therst methodof hieving optimizationandstability simultaneously ina generalwireless Marko queueing network,and forderiving per-bounds dire fromthe heduling

Ngày tải lên: 14/09/2015, 12:46

... and robustness of wireless mobile ad-hoc networks are limited due to many factors, such as the node resource and changing topologies We are therefore interested in investigating the outstanding ... network coding in wireless mobile ad-hoc networks In this thesis we propose to first study and investigate the performance behavior and key control parameters of opportunistic network coding in large ... variable-length coding header for the opportunistic network coding scheme, which is inserted into each packet If the routing protocol has its own header, our coding header sits in between the routing and MAC

Ngày tải lên: 16/10/2015, 11:59

... localization in wireless sensor networks Deyun Gao1, Ping Chen2, Chuan Heng Foh3*and Yanchao Niu1 Abstract In wireless sensor networks (WSNs), location information plays an important role in many ... services which includes geographic routing, target tracking, location-based coverage, topology control, and others One promising approach in sensor network localization is the determination of location ... transporta-tion control Spatial informatransporta-tion is crucial for sensor data to be interpreted meaningfully in many domains such as environmental monitoring, smart building fail-ure detection, and military

Ngày tải lên: 20/06/2014, 22:20

... bootstrapping, applying a DCA private key, joining a new CH, evicting an existing CH, refreshing CH shares In Bootstrapping operation, to construct the shared key and establish a (k,n) threshold sharing ... even in the destination cluster or position Also, we can consider two kind of client nodes mobility, nodes mobility inside the nodes administrative domain and between the administrative domains ... flooding Utilize route cache information, creating reverse path in CREQ forwarding [13] Reactive routing protocols Piggybacking of CREQ & CREP on the routing packets CRLs maintenance and deployment

Ngày tải lên: 20/06/2014, 22:20

... in Wireless Sensor Networks (PhD thesis, University of Maryland, 2004) 5 SA Borbash, A Ephremides, Wireless link scheduling with power control and SINR constraints IEEE Trans Inf ... the mini- mum-length schedul ing problem only for time-invariant wireless networks. Since the wireless channel in reality is time-varying, in the second part of this paper, we Pantelidou and Ephremides ... interested in obtaining optimal policies that take joint scheduling and rate control deci- sions under the objective of minimizing the (expected) time to deliver all data to the intended destinations.

Ngày tải lên: 20/06/2014, 22:20

... hierarchical structure introduces several problems, such as configuration advertising, discovery, maintenance, as well as ad hoc addressing, self-routing, and security [3] In our internetworking model, a ... seamless handovers between access points In parallel to the wireless mesh architecture, in our system model, we have the presence of independent mobile ad hoc networks as shown in red in Figure ... unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited Future wireless networks like mobile ad hoc networks and wireless mesh networks are expected

Ngày tải lên: 21/06/2014, 11:20

... has Topology Control in Wireless Ad Hoc and Sensor Networks P. Santi  2005 John Wiley & Sons, Ltd Simpo PDF Merge and Split Unregistered Version - http://www.simpopdf.com 10 AD HOC AND SENSOR ... http://www.simpopdf.com 2 Modeling Ad Hoc Networks In this chapter, we introduce a simple but widely accepted model of ad hoc network. Since sensor networks are a subclass of ad hoc networks, this ... resource on topology control in wireless ad hoc and sensor networks, a topic that has been a subject of intensive research in recent years. Indeed, this research field is far from being settled, and several...

Ngày tải lên: 27/06/2014, 00:20