Results 1  10
of
15
AdHoc Networks Beyond Unit Disk Graphs
, 2003
"... In this paper we study a model for adhoc networks close enough to reality as to represent existing networks, being at the same time concise enough to promote strong theoretical results. The Quasi Unit Disk Graph model contains all edges shorter than a parameter d between 0 and 1 and no edges longer ..."
Abstract

Cited by 116 (11 self)
 Add to MetaCart
In this paper we study a model for adhoc networks close enough to reality as to represent existing networks, being at the same time concise enough to promote strong theoretical results. The Quasi Unit Disk Graph model contains all edges shorter than a parameter d between 0 and 1 and no edges longer than 1. We show that  in comparison to the cost known on Unit Disk Graphs  the complexity results in this model contain the additional factor 1/d&sup2;. We prove that in Quasi Unit Disk Graphs flooding is an asymptotically messageoptimal routing technique, provide a geometric routing algorithm being more efficient above all in dense networks, and show that classic geometric routing is possible with the same performance guarantees as for Unit Disk Graphs if d 1/ # 2.
Does Topology Control Reduce Interference
 In Proceedings of the 5 th ACM International Symposium on Mobile Ad Hoc Networking and Computing (MOBIHOC
, 2004
"... Topology control in adhoc networks tries to lower node energy consumption by reducing transmission power and by confining interference, collisions and consequently retransmissions. Commonly low interference is claimed to be a consequence to sparseness of the resulting topology. In this paper we dis ..."
Abstract

Cited by 100 (8 self)
 Add to MetaCart
Topology control in adhoc networks tries to lower node energy consumption by reducing transmission power and by confining interference, collisions and consequently retransmissions. Commonly low interference is claimed to be a consequence to sparseness of the resulting topology. In this paper we disprove this implication. In contrast to most of the related work—claiming to solve the interference issue by graph sparseness without providing clear argumentation or proofs—, we provide a concise and intuitive definition of interference. Based on this definition we show that most currently proposed topology control algorithms do not effectively constrain interference. Furthermore we propose connectivitypreserving and spanner constructions that are interferenceminimal.
Topology control meets sinr: the scheduling complexity of arbitrary topologies
 in Proceedings of ACM MobiHoc
, 2006
"... To date, topology control in wireless ad hoc and sensor networks—the study of how to compute from the given communication network a subgraph with certain beneficial properties—has been considered as a static problem only; the time required to actually schedule the links of a computed topology with ..."
Abstract

Cited by 77 (9 self)
 Add to MetaCart
To date, topology control in wireless ad hoc and sensor networks—the study of how to compute from the given communication network a subgraph with certain beneficial properties—has been considered as a static problem only; the time required to actually schedule the links of a computed topology without message collision was generally ignored. In this paper we analyze topology control in the context of the physical SignaltoInterferenceplusNoiseRatio (SINR) model, focusing on the question of how and how fast the links of a resulting topology can actually be realized over time. For this purpose, we define and study a generalized version of the SINR model and obtain theoretical upper bounds on the scheduling complexity of arbitrary topologies in wireless networks. Specifically, we prove that even in worstcase networks, if the signals are transmitted with correctly assigned transmission power levels, the number of time slots required to successfully schedule all links of an arbitrary topology is proportional to the squared logarithm of the number of network nodes times a previously defined static interference measure. Interestingly, although originally considered without explicit accounting for signal collision in the SINR model, this static interference measure plays an important role in the analysis of link scheduling with physical link interference. Our result thus bridges the gap between static graphbased interference models and the physical SINR model. Based on these results, we also show that when it comes to scheduling, requiring the communication links to be symmetric may imply significantly higher costs as opposed to topologies allowing unidirectional links.
XTC: A Practical Topology Control Algorithm for AdHoc Networks
 In 4th International Workshop on Algorithms for Wireless, Mobile, Ad Hoc and Sensor Networks (WMAN
, 2003
"... The XTC adhoc network topology control algorithm introduced in this paper shows three main advantages over previously proposed algorithms. First, it is extremely simple and strictly local. Second, it does not assume the network graph to be a Unit Disk Graph; XTC proves correct also on general weigh ..."
Abstract

Cited by 69 (9 self)
 Add to MetaCart
The XTC adhoc network topology control algorithm introduced in this paper shows three main advantages over previously proposed algorithms. First, it is extremely simple and strictly local. Second, it does not assume the network graph to be a Unit Disk Graph; XTC proves correct also on general weighted network graphs. Third, the algorithm does not require availability of node position information. Instead, XTC operates with a general notion of order over the neighbors' link qualities. In the special case of the network graph being a Unit Disk Graph, the resulting topology proves to have bounded degree, to be a planar graph, andon averagecase graphsto be a good spanner.
A Robust Interference Model for Wireless Ad Hoc Networks
 5th International Workshop on Algorithms for Wireless, Mobile, Ad Hoc and Sensor Networks (WMAN
, 2005
"... Among the foremost goals of topology control in wireless adhoc networks is interference reduction. This paper presents a receivercentric interference model featuring two main advantages over previous work. First, it reflects the fact that interference occurs at the intended receiver of a message. ..."
Abstract

Cited by 38 (5 self)
 Add to MetaCart
Among the foremost goals of topology control in wireless adhoc networks is interference reduction. This paper presents a receivercentric interference model featuring two main advantages over previous work. First, it reflects the fact that interference occurs at the intended receiver of a message. Second, the presented interference measure is robust with respect to addition or removal of single network nodes. Regarding both of these aspects our model intuitively corresponds to the behavior of interference in reality. Based on this interference model, we show that currently known topology control algorithms poorly reduce interference. Motivated by the observation that already onedimensional network instances display the intricacy of the considered problem, we continue to focus on the socalled highway model. Setting out to analyze the special case of the exponential node chain, we eventually describe an algorithm guaranteeing to achieve a 4 √ ∆approximation of the optimal connectivitypreserving topology in the general highway model. 1.
An algorithmic approach to geographic routing in ad hoc and sensor networks
 IEEE/ACM Trans. Netw
"... Abstract—The one type of routing in ad hoc and sensor networks that currently appears to be most amenable to algorithmic analysis is geographic routing. This paper contains an introduction to the problem field of geographic routing, presents a specific routing algorithm based on a synthesis of the g ..."
Abstract

Cited by 11 (0 self)
 Add to MetaCart
Abstract—The one type of routing in ad hoc and sensor networks that currently appears to be most amenable to algorithmic analysis is geographic routing. This paper contains an introduction to the problem field of geographic routing, presents a specific routing algorithm based on a synthesis of the greedy forwarding and face routing approaches, and provides an algorithmic analysis of the presented algorithm from both a worstcase and an averagecase perspective. Index Terms—Algorithmic analysis, routing, stretch, wireless networks.
Abstract Algorithms for ad hoc and sensor networks *
, 2004
"... Wireless and mobiles networks are excellent playground for researchers with an algorithm background. Many research problem turn out to be variants of classic graph theory problems. In particular the rapidly growing areas for ad hoc and sensor networks demand new solutions for timeless graph theory p ..."
Abstract

Cited by 5 (0 self)
 Add to MetaCart
Wireless and mobiles networks are excellent playground for researchers with an algorithm background. Many research problem turn out to be variants of classic graph theory problems. In particular the rapidly growing areas for ad hoc and sensor networks demand new solutions for timeless graph theory problems, because: (i) wireless devices have lower bandwidth and (ii) wireless devices are mobile and therefore the topology of the network changes rather frequently. As a consequences, algorithms for wireless and mobile networks should have: (i) as little communication as possible and should (ii) run as fast as possible. Both goals can only be achieved by developing algorithms requiring a small number of communication rounds only (socalled local algorithm). In the work we present a few algorithmic applications in wireless networking, such as clustering, topology control and georouting. Each section is supplemented with an open problem. q 2005 Elsevier B.V. All rights reserved.
AdHoc and Sensor Networks: WorstCase vs. AverageCase
 in Proceedings of International Zurich Seminar on Communications, 2004
, 2004
"... Adhoc and sensor networks are rapidly growing areas of research which study the problems arising when small and feeble devices build a communication infrastructure. A vast majority of researchers in the field make strong averagecase assumptions about these networks, for example that the devices ar ..."
Abstract

Cited by 3 (0 self)
 Add to MetaCart
Adhoc and sensor networks are rapidly growing areas of research which study the problems arising when small and feeble devices build a communication infrastructure. A vast majority of researchers in the field make strong averagecase assumptions about these networks, for example that the devices are distributed uniformly at random. To system builders on the other hand many of these assumptions appear suspicious. In this paper we advocate an algorithmic (worstcase) approach to adhoc and sensor networking. We survey a few also worstcase efficient algorithms for topology control, clustering, and routing. I.
XTC: A Practical Topology Control Algorithm for AdHoc Networks
"... The XTC adhoc network topology control algorithm introduced in this paper shows three main advantages over previously proposed algorithms. First, it is extremely simple and strictly local. Second, it does not assume the network graph to be a Unit Disk Graph; XTC proves correct also on general weigh ..."
Abstract
 Add to MetaCart
The XTC adhoc network topology control algorithm introduced in this paper shows three main advantages over previously proposed algorithms. First, it is extremely simple and strictly local. Second, it does not assume the network graph to be a Unit Disk Graph; XTC proves correct also on general weighted network graphs. Third, the algorithm does not require availability of node position information. Instead, XTC operates with a general notion of order over the neighbors ’ link qualities. In the special case of the network graph being a Unit Disk Graph, the resulting topology proves to have bounded degree, to be a planar graph, and—on averagecase graphs—to be a good spanner. 1
AdHoc and Sensor Networks: WorstCase vs. AverageCase
"... Abstract — Adhoc and sensor networks are rapidly growing areas of research which study the problems arising when small and feeble devices build a communication infrastructure. A vast majority of researchers in the field make strong averagecase assumptions about these networks, for example that the ..."
Abstract
 Add to MetaCart
Abstract — Adhoc and sensor networks are rapidly growing areas of research which study the problems arising when small and feeble devices build a communication infrastructure. A vast majority of researchers in the field make strong averagecase assumptions about these networks, for example that the devices are distributed uniformly at random. To system builders on the other hand many of these assumptions appear suspicious. In this paper we advocate an algorithmic (worstcase) approach to adhoc and sensor networking. We survey a few also worstcase efficient algorithms for topology control, clustering, and routing. I.