Jean Walrand

Jean Walrand
University of California, Berkeley | UCB · Department of Electrical Engineering and Computer Sciences

PhD EECS

About

323
Publications
47,640
Reads
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15,448
Citations
Introduction
Additional affiliations
January 1982 - present
University of California, Berkeley
Position
  • Professor (Full)
Education
September 1975 - June 1979

Publications

Publications (323)
Article
Full-text available
It was shown recently that carrier sense multiple access (CSMA)-like distributed algorithms can achieve the maximal throughput in wireless networks (and task processing networks) under certain assumptions. One important but idealized assumption is that the sensing time is negligible, so that there is no collision. In this paper, we study more pract...
Article
Full-text available
In multihop wireless networks, designing distributed scheduling algorithms to achieve the maximal throughput is a challenging problem because of the complex interference constraints among different links. Traditional maximal-weight scheduling (MWS), although throughput-optimal, is difficult to implement in distributed networks. On the other hand, a...
Article
Full-text available
We show the existence of effective bandwidths for multiclass Markov fluids and other types of sources that are used to model ATM traffic. More precisely, we show that when such sources share a buffer with deterministic service rate, a constraint on the tail of the buffer occupancy distribution is a linear constraint on the number of sources. That i...
Article
We consider a problem of prediction based on opinions elicited from heterogeneous rational agents with private information. Making an accurate prediction with a minimal cost requires a joint design of the incentive mechanism and the prediction algorithm. To elicit heterogeneous agents' private information and incentivize agents with different capab...
Chapter
The most basic operation of a network is to transport bits. Communication links perform that task and form the Physical Layer of the network.
Chapter
The goal of this more mathematically demanding chapter is to explain some recent insight into the operations of network protocols. We start with a review of some basic results on graphs. Queueing is a commonplace occurrence in network operations. In order to better design network protocols, it is important to understand the queueing dynamics. Two o...
Chapter
This chapter explores how various networks determine the paths that packets should follow.
Chapter
The previous chapters explained the main operation and organization principles of networks. In this chapter, we discuss a number of additional topics.
Chapter
The Internet is a collection of networks. The key idea is to interconnect networks that possibly use different technologies, such as wireless, wired, optical, and whatever.
Chapter
The transport layer supervises the end-to-end delivery across the Internet between a process in a source device and a process in a destination device. The transport protocol of Internet implements two transport services: a connection-oriented reliable byte stream delivery service and a connectionless datagram delivery service. This chapter explains...
Chapter
The Internet grew from a small experiment in the late 1960s to a network that connects about 3.7 billion users (in June 2017) and has become society’s main communication system. This phenomenal growth is rooted in the architecture of the Internet that makes it scalable, flexible, and extensible, and provides remarkable economies of scale. In this c...
Chapter
In networking, connectivity is the name of the game. The Internet connects a few billion computers across the world, plus associated devices such as printers, servers, and web cams. With the development of the Internet of Things, hundreds of billions of devices will soon be connected via the Internet. By “connect,” we mean that the Internet enables...
Chapter
Ethernet is a technology used to connect up to a few hundred computers and devices. The connections use wires of up to 100 m or fibers of up to a few km. The bit rate on these wires and fibers is usually 100 Mbps but can go to 1 Gbps or even 10 Gbps. The vast majority of computers on the Internet are attached to an Ethernet network or, increasingly...
Article
Modern processing networks often consist of heterogeneous servers with widely varying capabilities, and process job flows with complex structure and requirements. A major challenge in designing efficient scheduling policies in these networks is the lack of reliable estimates of system parameters, and an attractive approach for addressing this chall...
Article
We consider the stability of robust scheduling policies for multiclass queueing networks. These are open networks with arbitrary routeing matrix and several disjoint groups of queues in which at most one queue can be served at a time. The arrival and potential service processes and routeing decisions at the queues are independent, stationary, and e...
Conference Paper
Telecommunication networks are generally dimensioned to provide services with small delays and high throughput during peak-periods. Due to the sizable difference in the network utilization between the peak and off-peak periods as well as the requirements of robust performance in face of both traffic burstiness and various types of network failures,...
Article
Full-text available
We consider a problem of prediction based on opinions elicited from heterogeneous rational agents with private information. Making an accurate prediction with a minimal cost requires a joint design of the incentive mechanism and the prediction algorithm. Such a problem lies at the nexus of statistical learning theory and game theory, and arises in...
Conference Paper
Variable demand, dynamic electricity pricing and intermittent renewable energy are sources of variability and uncertainty in smart grid systems. Energy storage devices can be used to absorb these fluctuations and reduce the overall cost. The goal is to find the best policy for storing, buying, selling and using energy in the presence of this variab...
Article
Full-text available
As the successor to the 3G standard, the 4G cellular standard provides much higher data rates to address cellular users’ ever-increasing demands for high-speed multimedia communications. This paper analyzes the cellular operators’ timing of network upgrades, by considering user subscription dynamics induced by switching from 3G to 4G technologies....
Article
Sensor nodes equipped with renewable energy sources are capable of recharging their batteries and supporting data collection and transmission indefinitely. Energy and data management of these types of systems is challenging primarily due to the variability of renewable energy sources and transmission channels. This paper explores a methodology for...
Article
We consider a general flexible fork-join processing network, in which jobs are modeled as directed acyclic graphs with nodes representing tasks, and edges representing precedence constraints among tasks. Both servers and tasks are flexible in the sense that each task can be processed by several servers, which in turn can serve multiple task types....
Article
We consider the problem of scheduling jobs which are modeled by directed acyclic graphs (DAG). In such graphs, nodes represent tasks of a job and edges represent precedence constraints in processing these tasks. The DAG scheduling problem, also known as scheduling in fork-join processing networks, is motivated by examples such as job scheduling in...
Article
This paper studies the control of systems that store renewable energy. The problem is to maximize the long-term utility of the energy by controlling how it is used. The methodology for designing the control policy depends on the size of the battery. If the battery is small, the control policy is determined by solving a Markov decision problem. If t...
Conference Paper
We consider a general flexible queueing network in which each queue can be processed by several servers, which in turn can serve multiple queues. Important special cases of this model include open multiclass queueing networks [11] and flexible parallel server systems [16]. A scheduling policy decides how server capacities are allocated over time. I...
Article
Full-text available
This paper analyzes and compares different incentive mechanisms for a master to motivate the collaboration of smartphone users on both data acquisition and distributed computing applications. To collect massive sensitive data from users, we propose a reward-based collaboration mechanism, where the master announces a total reward to be shared among...
Conference Paper
We consider arbitrary risk-averse users, whose costs of improving security are given by an arbitrary convex function. In our model, user probability to incur damage (from an attack) depends on both his own security and network security: thus, security is interdependent. We introduce two user types (normal and malicious), and allow one user type (ma...
Article
Full-text available
We study a simple rate control scheme for a multiclass queuing network for which customers are partitioned into distinct flows that are queued separately at each station. The control scheme discards customers that arrive to the network ingress whenever any one of the flow's queues throughout the network holds more than a specified threshold number...
Conference Paper
Full-text available
As the successor to the 3G standard, 4G provides much higher data rates to address cellular users' ever-increasing demands for high-speed multimedia communications. This paper analyzes the cellular operators' timing of network upgrades and models that users can switch operators and services. Being the first to upgrade 3G to 4G service, an operator...
Article
Allocating resources in networks to QoS flows may require undesirable delays or costs. We consider a dynamic Service Level Agreement (SLA) negotiation scheme between peer autonomous systems (ASes) that implement DiffServ per domain behaviors. For concreteness, we tailor our scheme to account for the needs of Voice over IP transport across multiple...
Article
Full-text available
This paper presents a dynamic Service Level Agreement (SLA) negotiation scheme between peer autonomous systems (ASes) that implement DiffServ per domain behaviors. For concreteness, we tailor our scheme to account for the needs of VoIP transport across multiple ASes. We present a heuristic but computationally simple and distributed scheme that uses...
Article
Full-text available
We consider the stability of robust scheduling policies for Lu-Kumar networks. These are open networks with arbitrary routing matrix and several disjoint groups of queues in which at most one queue can be served at a time in each group. The arrival and potential service processes and routing decisions at the queues are independent, stationary and e...
Article
Full-text available
This Special issue on the "Economics of Communication Networks and Systems" brings together state-of-the-art research contributions that address major opportunities and challenges of economic and incentive issues in communication networks and wireless systems, using tools such as game theory, pricing, contract theory, mechanism design, with emphasi...
Article
This paper explains recent results on distributed algorithms for networks of conflicting queues. At any given time, only specific subsets of queues can be served simultaneously. The challenge is to select the subsets in a distributed way to stabilize the queues whenever the arrival rates are feasible. One key idea is to formulate the subset selecti...
Conference Paper
This paper proposes a new type of range-free localization method based on affine transformation. Nodes extract subgraphs with a grid topology from a sensor network and assign x-y coordinates to themselves in a decentralized manner. The nodes estimate their positions using an affine transformation based on the mapping of the physical positions and t...
Article
Full-text available
Benes networks are constructed with simple switch modules and have many advantages, including small latency and requiring only an almost linear number of switch modules. As circuit-switches, Benes networks are rearrangeably non-blocking, which implies that they are full-throughput as packet switches, with suitable routing. Routing in Benes networks...
Conference Paper
Full-text available
In this paper, we propose a quantification of the vulnerability of a communication network where links are subject to failures due to the actions of a strategic adversary. We model the adversarial nature of the problem as a 2-player game between a network manager who chooses a spanning tree of the network as communication infrastructure and an atta...
Article
Full-text available
In this paper, we consider the problem of optimal demand response and energy storage management for a power consuming entity. The entity's objective is to find an optimal control policy for deciding how much load to consume, how much power to purchase from/sell to the power grid, and how to use the finite capacity energy storage device and renewabl...
Article
Full-text available
This paper analyzes and compares different incentive mechanisms for a client to motivate the collaboration of smartphone users on both data acquisition and distributed computing applications.
Article
In this paper, we develop a low-complexity scheme OpTar for designing optimal power tariffs. OpTar provides an easy way for the utility companies to adjust their power prices, and allows the users to pre-plan their power consumption. OpTar is robust against system dynamics including time-varying power market conditions and user preferences. It can...
Conference Paper
Full-text available
This paper uses a two-sided market model to study if last-mile access providers (ISPs), should charge content providers (CPs), who derive revenue from advertisers, for the right to access ISP's end-users. We compare two-sided pricing (ISPs could charge CPs for content deliv-ery) with one-sided pricing (neutrality regulations prohibit such charges)....
Article
Full-text available
In this paper, we propose a general operating scheme which allows the utility company to jointly perform power procurement and demand response so as to maximize the social welfare. Our model takes into consideration the effect of the renewable energy and the multi-stage feature of the power procurement process. It also enables the utility company t...
Conference Paper
Flat-rate pricing has been the dominant scheme for tariffing Internet services due to its popularity and simplicity. However, this scheme does not provide incentives for users to use network resources efficiently. As the demand for wireless video and other resource-intensive services grows faster than the providers' ability to expand the network ca...
Article
Abstract—We consider a multi-cell wireless network with a large number of users. Each user selfishly chooses the Base Station (BS) that gives it the best throughput (utility), and each BS allocates its resource by some simple scheduling policy. First we consider two cases: (1) BS allocates the same time to its users; (2) BS allocates the same throu...
Article
This paper studies a concrete pursuit-evasion game in which the evader, a.k.a. the intruder, tries to reach a harbor via a rectangular channel, while the pursuer, a.k.a. the defender, tries to stop him. Our goal is to develop insight into the nature of this game, the impact of the quality of information, and the potential evasion and defense numeri...
Article
This paper investigates the connection between network reliability and security by modeling attacker-defender interactions as a game. We model the defender's network as an undirected graph with insecure and unreliable edges. The edges could either fail due to a random malfunction (fault), or due to a strategic attacker who aims to maximize the defe...
Conference Paper
Full-text available
Glauber dynamics is a powerful tool to generate randomized, approximate solutions to combinatorially difficult problems. It has been recently used to design distributed CSMA scheduling algorithms for multi-hop wireless networks. In this paper, we derive bounds on the mixing time of a generalization of Glauber dynamics where multiple links update th...
Conference Paper
Full-text available
Networking researchers complain that the current Internet is ossified, i.e. that it can hardly be changed. We believe that one of the fundamental reasons for that is the lack of appropriate incentives for providers to invest in new technology, especially in the absence of a compelling new architecture and a killer application that would benefit fro...
Article
Full-text available
We study a network security game where strategic players choose their investments in security. Since a player's investment can reduce the propagation of computer viruses, a key feature of the game is the positive externality exerted by the investment. With selfish players, unfortunately, the overall network security can be far from optimum. The con...
Conference Paper
Full-text available
The paper studies one-shot two-player games with non-Bayesian uncertainty. The players have an attitude that ranges from optimism to pessimism in the face of uncertainty. Given the attitudes, each player forms a belief about the set of possible strategies of the other player. If these beliefs are consistent, one says that they form an uncertainty e...
Article
Full-text available
This paper provides proofs of the rate stability, Harris recurrence, and ε-optimality of carrier sense multiple access (CSMA) algorithms where the random access (or backoff) parameter of each node is adjusted dynamically. These algorithms require only local information and they are easy to implement. The setup is a network of wireless nodes with a...
Article
Full-text available
This paper investigates Internet service provider (ISP) incentives with a single-service class and with two-service classes in the Internet. We consider multiple competing ISPs who offer network access to a fixed user base, consisting of end-users who differ in their quality requirements and willingness to pay for the access. We model user-ISP inte...
Conference Paper
We study the strategic interaction between a network manager whose goal is to choose (as communication infrastructure) a spanning tree of a network given as an undirected graph, and an attacker who is capable of attacking a link in the network. We model their interaction as a zero-sum game and discuss a particular set of Nash equilibria. More speci...
Article
Many incompatible wireless protocols proliferate in unlicensed bands, creating complex coexistence and connectivity problems. If the trend continues, such problems will continue to exist in future unlicensed bands. We take a different approach to spectrum sharing. Instead of proposing a distinct medium-access control (MAC) protocol for each type of...
Article
Full-text available
Glauber dynamics is a powerful tool to generate randomized, approximate solutions to combinatorially difficult problems. It has been used to analyze and design distributed CSMA (Carrier Sense Multiple Access) scheduling algorithms for multi-hop wireless networks. In this paper we derive bounds on the mixing time of a generalization of Glauber dynam...
Article
Full-text available
This paper investigates how competitive cyber-insurers affect network se-curity and welfare of the networked society. In our model, a user's probability to incur damage (from being attacked) depends on both his security and the network security, with the latter taken by individual users as given. First, we consider cyber-insurers who cannot observe...
Conference Paper
Full-text available
The interdependent nature of security on the Internet causes a negative externality that results in under-investment in technology-based defences. Previous research suggests that, in such an environment, cyber-insurance may serve as an important tool not only to manage risks but also to improve the incentives for investment in security. This paper...
Conference Paper
Full-text available
CSMA-based scheduling is a recently proposed distributed scheduling algorithm that is shown to achieve the maximal throughput. Central to this algorithm is a Markov chain that produces samples from a desired distribution. In this work, we discuss the relationships of the achievable throughput, queueing delay and the mixing time of the Markov chain...
Book
This book results from many years of teaching an upper division course on communication networks in the EECS department at University of California, Berkeley. It is motivated by the perceived need for an easily accessible textbook that puts emphasis on the core concepts behind current and next generation networks. After an overview of how today's I...
Conference Paper
Designing efficient scheduling algorithms is an important problem in a general class of networks with resource-sharing constraints, such as wireless networks and stochastic processing networks [7]. In [5], we proposed a distributed scheduling algorithm that can achieve the maximal throughput in such networks under certain conditions. This algorithm...
Book
In this book, we consider the problem of achieving the maximum throughput and utility in a class of networks with resource-sharing constraints. This is a classical problem of great importance. In the context of wireless networks, we first propose a fully distributed scheduling algorithm that achieves the maximum throughput. Inspired by CSMA (Carrie...
Chapter
In this chapter, we consider the scheduling of wireless nodes, assuming perfect CSMA and no hidden nodes, as we did in Chapter 2. The arrival rates are fixed and each packet reaches its intended receiver in one hop. We model the interference between links by a conflict graph. The objective is to design a distributed scheduling protocol to keep up w...
Chapter
In Chapter 3, the problem was to design a distributed scheduling algorithm to keep up with fixed arrival rates when the transmissions are single hop. In this chapter, we study the combined admission control, routing, and scheduling problem in a multi-hop network. That is, the arrival rates are not given ahead of time. Instead, the nodes exercise so...
Article
Full-text available
The paper studies one-shot two-player games with non-Bayesian uncertainty. The players have an attitude that ranges from optimism to pessimism in the face of uncertainty. Given the attitudes, each player forms a belief about the set of possible strategies of the other player. If these beliefs are consistent, one says that they form an uncertainty e...
Conference Paper
Full-text available
Stochastic Processing Networks (SPNs) model manufacturing, communication, and service systems. In such a network, service activities require parts and resources to produce other parts. Because service activities compete for resources, a scheduling problem arises. This paper proposes a deficit maximum weight (DMW) algorithm to achieve throughput opt...
Conference Paper
Full-text available
Femtocells or home base stations are a proposed solution to the problem of degraded indoor service from the macrocell base station in future 4G data networks. In this paper, we study user incentives for the adoption of femtocells and their resulting impact on network operator revenues. We model a monopolist network operator who offers the option of...
Article
Full-text available
This paper provides proofs of the rate stability, Harris recurrence, and epsilon-optimality of CSMA algorithms where the backoff parameter of each node is based on its backlog. These algorithms require only local information and are easy to implement. The setup is a network of wireless nodes with a fixed conflict graph that identifies pairs of node...
Conference Paper
Full-text available
The motivation for this paper is to analyze the effect of information uncertainty on the design and performance of protocols. The paper considers two types of situations. The first is when different nodes in the network have bounded knowledge about what other nodes know. The second, called common knowledge about inconsistent beliefs, is when the in...
Article
Full-text available
It was shown recently that CSMA (Carrier Sense Multiple Access)-like distributed algorithms can achieve the maximal throughput in wireless networks (and task processing networks) under certain assumptions [1]. One idealized assumption is that the sensing time is negligible, so that there is no collision. In this paper, we study more practical CSMA-...
Article
Full-text available
From February 8-11, 2009, the Dagstuhl Seminar ``Bandwidth on Demand'' was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During this seminar, participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the talks given during the seminar are put together in this paper. @InProceedings{a...
Article
We address whether local ISPs should be allowed to charge content providers, who derive advertising revenue, for the right to access end-users. We compare two-sided pricing where such charges are allowed to one-sided pricing where they are prohibited. By deriving provider equilibrium actions (prices and investments), we determine which regime is we...
Article
Full-text available
We address whether local ISPs should be allowed to charge content providers, who derive advertising revenue, for the right to access end-users. We compare two-sided pricing where such charges are allowed to one-sided pricing where they are prohibited. By deriving provider equilibrium actions (prices and investments), we determine which regime is we...
Conference Paper
Full-text available
In this paper, we investigate the welfare effects of transition from a single-service class to two-service classes in the Internet. We consider an ISP who offers network access to a fixed user base, consisting of users who differ in their quality requirements and willingness to pay for the access. We model user-ISP interactions as a game in which t...
Conference Paper
Full-text available
Entropy plays a central role in communication systems. On the one hand, the objective of communication is to reduce the entropy of some random variable. On the other hand, many useful models of communication networks evolve to a state of maximum entropy given external constraints. Chemical systems also exhibit a similar entropy-maximizing property,...
Conference Paper
Full-text available
This paper addresses QoS provision in the presence of the regulatory threat of network neutrality. We formulate a technological implementation that enables QoS provision while requiring minimum alteration of the current network. Our proposal permits to avoid the political economic shock that would accompany any major network neutrality regulation....