In this paper, we present a family of adaptive protocols, called SPIN (Sensor Protocols for Information via Negotiation), that efficiently disseminates information among sensors in an energy-constrained wireless sensor network. Nodes running a SPIN communication protocol name their data using high-level data descriptors, called meta-data. They use meta-data negotiations to eliminate the transmission of redundant data throughout the network. In addition, SPIN nodes can base their communication decisions both upon application-specific knowledge of the data and upon knowledge of the resources that are available to them. This allows the sensors to efficiently distribute data given a limited energy supply. We simulate and analyze the performance of two specific SPIN protocols, comparing them to other possible approaches and a theoretically optimal protocol. We find that the SPIN protocols can deliver 60% more data for a given amount of energy than conventional approaches. We also find that, in terms of dissemination rate and energy usage, the SPlN protocols perform close to the theoretical optimum.

/pdf/adaptive-protocols-for-information-dissemination-in-wireless-2lo594hki6.pdf

Adaptive protocols for information dissemination in wireless sensor networks

In the Hamadryas baboon, males are substantially larger than females. A troop of baboons is subdivided into a number of ‘one-male groups’, consisting of one adult male and one or more females with their young. The male prevents any of ‘his’ females from moving too far from him. Kummer (1971) performed the following experiment. Two males, A and B, previously unknown to each other, were placed in a large enclosure. Male A was free to move about the enclosure, but male B was shut in a small cage, from which he could observe A but not interfere. A female, unknown to both males, was then placed in the enclosure. Within 20 minutes male A had persuaded the female to accept his ownership. Male B was then released into the open enclosure. Instead of challenging male A , B avoided any contact, accepting A’s ownership.

Evolution and the Theory of Games

Topology Control (TC) is one of the most important techniques used in wireless ad hoc and sensor networks to reduce energy consumption (which is essential to extend the network operational time) and radio interference (with a positive effect on the network traffic carrying capacity). The goal of this technique is to control the topology of the graph representing the communication links between network nodes with the purpose of maintaining some global graph property (e.g., connectivity), while reducing energy consumption and/or interference that are strictly related to the nodes' transmitting range. In this article, we state several problems related to topology control in wireless ad hoc and sensor networks, and we survey state-of-the-art solutions which have been proposed to tackle them. We also outline several directions for further research which we hope will motivate researchers to undertake additional studies in this field.

/pdf/topology-control-in-wireless-ad-hoc-and-sensor-networks-3e17u396zt.pdf

Topology Control in Wireless Ad Hoc and Sensor Networks

In this paper, we present a family of adaptive protocols, called SPIN (Sensor Protocols for Information via Negotiation), that efficiently disseminate information among sensors in an energy-constrained wireless sensor network. Nodes running a SPIN communication protocol name their data using high-level data descriptors, called meta-data. They use meta-data negotiations to eliminate the transmission of redundant data throughout the network. In addition, SPIN nodes can base their communication decisions both upon application-specific knowledge of the data and upon knowledge of the resources that are available to them. This allows the sensors to efficiently distribute data given a limited energy supply. We simulate and analyze the performance of four specific SPIN protocols: SPIN-PP and SPIN-EC, which are optimized for a point-to-point network, and SPIN-BC and SPIN-RL, which are optimized for a broadcast network. Comparing the SPIN protocols to other possible approaches, we find that the SPIN protocols can deliver 60% more data for a given amount of energy than conventional approaches in a point-to-point network and 80% more data for a given amount of energy in a broadcast network. We also find that, in terms of dissemination rate and energy usage, the SPIN protocols perform close to the theoretical optimum in both point-to-point and broadcast networks.

/pdf/negotiation-based-protocols-for-disseminating-information-in-1i6jhgr0p8.pdf

Negotiation-based protocols for disseminating information in wireless sensor networks

This self-contained introduction to the distributed control of robotic networks offers a distinctive blend of computer science and control theory. The book presents a broad set of tools for understanding coordination algorithms, determining their correctness, and assessing their complexity; and it analyzes various cooperative strategies for tasks such as consensus, rendezvous, connectivity maintenance, deployment, and boundary estimation. The unifying theme is a formal model for robotic networks that explicitly incorporates their communication, sensing, control, and processing capabilities--a model that in turn leads to a common formal language to describe and analyze coordination algorithms.Written for first- and second-year graduate students in control and robotics, the book will also be useful to researchers in control theory, robotics, distributed algorithms, and automata theory. The book provides explanations of the basic concepts and main results, as well as numerous examples and exercises.Self-contained exposition of graph-theoretic concepts, distributed algorithms, and complexity measures for processor networks with fixed interconnection topology and for robotic networks with position-dependent interconnection topology Detailed treatment of averaging and consensus algorithms interpreted as linear iterations on synchronous networks Introduction of geometric notions such as partitions, proximity graphs, and multicenter functions Detailed treatment of motion coordination algorithms for deployment, rendezvous, connectivity maintenance, and boundary estimation

/pdf/distributed-control-of-robotic-networks-a-mathematical-1q6nfcvi2l.pdf

Distributed Control of Robotic Networks: A Mathematical Approach to Motion Coordination Algorithms

We consider the task of waking up an anonymous ad hoc radio network from a single source, by a deterministic algorithm. In the beginning only the source is awake and has to wake up other nodes by disseminating messages throughout the network. Nodes of the network do not know its topology and they do not have distinct labels. In such networks some nodes are impossible to reach. A node in a network is accessible if it can be woken up by some (possibly network-dependent) deterministic algorithm. A deterministic wakeup algorithm for ad hoc networks is universal if it wakes up all accessible nodes in all networks. We study the question of the existence of such a universal wakeup algorithm. For synchronous communication we design a universal wakeup algorithm, and for asynchronous communication we show that no such algorithm exists.

Waking up anonymous ad hoc radio networks

Time of Radio Broadcasting

Leader election is a basic symmetry breaking problem in distributed computing. All nodes of a network have to agree on a single node, called the leader. If the nodes of the network have distinct labels, then agreeing on a single node means that all nodes have to output the label of the elected leader. 
If the nodes are anonymous, the task of leader election is formulated as follows: every node of the network must output a simple path starting at it, which is coded as a sequence of port numbers, such that all these paths end at a common node, the leader. In this paper, we study deterministic leader election in anonymous trees. 
Our goal is to establish tradeoffs between the allocated time $\tau$ and the amount of information that has to be given {\em a priori} to the nodes of a network to enable leader election in time $\tau$. Following the framework of {\em algorithms with advice}, this information is provided to all nodes at the start by an oracle knowing the entire tree, in form of binary strings assigned to all nodes. There are two possible variants of formulating this advice assignment. Either the strings provided to all nodes are identical, or strings assigned to different nodes may be potentially different, i.e., advice can be {\em customized}. As opposed to previous papers on leader election with advice, in this paper we consider the latter option. 
The maximum length of all assigned binary strings is called the {\em size of advice}. 
For a given time $\tau$ allocated to leader election, we give upper and lower bounds on the minimum size of advice sufficient to perform leader election in time $\tau$. All our bounds except one pair are tight up to multiplicative constants, and in this one exceptional case, the gap between the upper and the lower bound is very small.

Leader Election in Trees with Customized Advice.

Cellular Networks: Where Are the Mobile Users?.- Distributed Data Structures: A Survey.- On Designing Truthful Mechanisms for Online Scheduling.- On Private Computation in Incomplete Networks.- Traffic Grooming on the Path.- Range Augmentation Problems in Static Ad-Hoc Wireless Networks.- On the Approximability of the L(h,k)-Labelling Problem on Bipartite Graphs (Extended Abstract).- A Tight Bound for Online Coloring of Disk Graphs.- Divide and Conquer Is Almost Optimal for the Bounded-Hop MST Problem on Random Euclidean Instances.- Distributed Exploration of an Unknown Graph.- Two Absolute Bounds for Distributed Bit Complexity.- Finding Short Right-Hand-on-the-Wall Walks in Graphs.- Space Lower Bounds for Graph Exploration via Reduced Automata.- Communications in Unknown Networks: Preserving the Secret of Topology.- An Improved Algorithm for Adaptive Condition-Based Consensus.- Biangular Circle Formation by Asynchronous Mobile Robots.- Hardness and Approximation Results for Black Hole Search in Arbitrary Graphs.- On Semi-perfect 1-Factorizations.- Free-Riders in Steiner Tree Cost-Sharing Games.- On the Feasibility of Gathering by Autonomous Mobile Robots.- Majority and Unanimity in Synchronous Networks with Ubiquitous Dynamic Faults.- Minimizing the Number of ADMs in SONET Rings with Maximum Throughput.- Optimal Gossiping in Square Meshes in All-Port Mode and with Short Packets.- Geometric Routing Without Geometry.

Structural Information and Communication Complexity: 12th International Colloquium, SIROCCO 2005, Mont Saint-Michel, France, May 24-26, 2005, Proceedings

The number of nodes of a network, called its size, and the largest distance between nodes of a network, called its diameter, are among the most important network parameters. Knowing the size and/or diameter is a prerequisite of many distributed network algorithms. A radio network is a collection of nodes, with wireless transmission and receiving capabilities. It is modeled as a simple undirected graph whose nodes communicate in synchronous rounds. In each round, a node can either transmit a message to all its neighbors, or stay silent and listen. At the receiving end, a node $v$ hears a message from a neighbor $w$ in a round $i$, if $v$ listens in round $i$, and if $w$ is its only neighbor that transmits in round $i$. If $v$ listens in a round, and multiple neighbors of $v$ transmit in this round, a collision occurs at $v$. If $v$ transmits in a round, it does not hear anything. If listening nodes can distinguish collision from silence, we say that the network has collision detection capability, otherwise there is no collision detection. We consider the tasks of size discovery and diameter discovery: finding the size (resp. the diameter) of an unknown radio network with collision detection. All nodes have to output the size (resp. the diameter) of the network, using a deterministic algorithm. Nodes have labels which are binary strings. The length of a labeling scheme is the largest length of a label. We concentrate on the following problems: 
1. What is the shortest labeling scheme that permits size discovery in all radio networks of maximum degree $\Delta$? 2. What is the shortest labeling scheme that permits diameter discovery in all radio networks? 
We show that the minimum length of a labeling scheme that permits size discovery is $\Theta(\log\log \Delta)$. By contrast, we show that diameter discovery can be done using a labeling scheme of constant length.

Andrzej Pelc

Papers

Waking up anonymous ad hoc radio networks

Time of Radio Broadcasting

Leader Election in Trees with Customized Advice.

Structural Information and Communication Complexity: 12th International Colloquium, SIROCCO 2005, Mont Saint-Michel, France, May 24-26, 2005, Proceedings

Finding the Size and the Diameter of a Radio Network Using Short Labels.