Jonathan W. Hui

• Doctor of Philosophy (Ph.D.), Computer Science
• University of California, Berkeley

Low-Power and Lossy Networks (LLNs) are a class of network in which both the routers and their interconnect are constrained. LLN routers typically operate with constraints on processing power, memory, and energy (battery power). Their interconnects are characterized by high loss rates, low data rates, and instability. LLNs are comprised of anything...

Many applications, ranging from wireless healthcare to energy metering on the smart grid, have emerged from a decade of research in wireless sensor networks. However, the lack of an IP-based network architecture precluded sensor networks from interoperating with the Internet, limiting their real-world impact. Given this disconnect, the IETF charter...

The Trickle algorithm allows nodes in a lossy shared medium (e.g., low-power and lossy networks) to exchange information in a highly robust, energy efficient, simple, and scalable manner. Dynamically adjusting transmission windows allows Trickle to spread new information on the scale of link-layer transmission times while sending only a few message...

With deeply embedded wireless sensors, a new tier of the Internet is emerging that will extend into the physical world. These wireless sensor nodes are expected to vastly outnumber conventional computer hosts as we see them today, but their strict resource constraints are unlike other technologies already common to the Internet. As wireless sensor...

Extending IP to low-power, wireless personal area networks (LoWPANs) was once considered impractical because these networks are highly constrained and must operate unattended for multiyear lifetimes on modest batteries. Many vendors embraced proprietary protocols, assuming that IP was too resource-intensive to be scaled down to operate on the micro...

A decade ago as wireless sensor network research took off many researchers in the field denounced the use of IP as inadequate and in contradiction to the needs of wireless sensor networking. Since then the field has matured, standard links have emerged, and IP has evolved. In this paper, we present the design of a complete IPv6-based network archit...

On August 30, 2005, we successfully demonstrated a large-scale, real-time, surveillance and control application on a wireless sensor network. The task was to track multiple human targets walking through a 5041 square meter sensor field and dispatch simulated pursuers to capture them. We employed a multi-target tracking algorithm that was a combinat...

This article describes one of the major efforts in the sensor network community to build an integrated sensor network system for surveillance missions. The focus of this effort is to acquire and verify information about enemy capabilities and positions of hostile targets. Such missions often involve a high element of risk for human personnel and re...

This article describes one of the major efforts in the sensor network community to build an integrated sensor network system for surveillance missions. The focus of this effort is to acquire and verify information about enemy capabilities and positions of hostile targets. Such missions often involve a high element of risk for human personnel and re...

We present the philosophy, design, and initial evaluation of the Trio Testbed, a new outdoor sensor network deploy- ment that consists of 557 solar-powered motes, seven gate- way nodes, and a root server. The testbed covers an area of approximately 50,000 square meters and was in contin- uous operation during the last four months of 2005. This new...

A main challenge with developing applications for wireless embedded systems is the lack of visibility and control during execution of an application. In this paper, we present a tool suite called Marionette that provides the ability to call functions and to read or write variables on pre-compiled, embedded programs at run-time, without requiring th...

A number of multi-hop, wireless, network programming systems have emerged for sensor network retasking but none of these systems support a cryptographically-strong, public-key-based system for source authentication and integrity verification. The traditional technique for authenticating a program binary, namely a digital signature of the program ha...

Web applications suffer from software and configuration faults that lower their availability. Recovering from failure is dominated by the time interval between when these faults appear and when they are detected by site operators. We introduce a set of tools that augment the ability of operators to perceive the presence of failure: an automatic ano...

Recent technological advances and the continuing quest for greater efficiency have led to an explosion of link and network protocols for wireless sensor networks. These protocols embody very different assumptions about network stack composition and, as such, have limited interoperability. It has been suggested [3] that, in principle, wireless senso...

Hard, machine-supported formal verification of software is at a turning point. Recent years have seen theorem proving tools maturing with a number of successful, real-life applications. At the same time, small high-performance OS kernels, which can drastically ...

The focus of surveillance missions is to acquire and verify information about enemy capabilities and positions of hostile targets. Such missions often involve a high element of risk for human personnel and require a high degree of stealthiness. Hence, the ability to deploy unmanned surveillance missions, by using wireless sensor networks, is of gre...

The focus of surveillance missions is to acquire and verify information about enemy capabilities and positions of hostile targets. Such missions often involve a high element of risk for human personnel and require a high degree of stealthiness. Hence, the ability to deploy unmanned surveillance missions, by using wireless sensor networks, is of gre...

In this paper, we analyze the end-to-end routing performance of a wireless sensor network with uncoordinated power management (UPM). In UPM, nodes power on and off with a predetermined duty cycle. We consider the effects of changing the specified duty cycle, spatial node density, and mobility on end-to-end delays, buffering requirements, and the ac...

To support network programming, we present Deluge, a reliable data dissemination protocol for propagating large data objects from one or more source nodes to many other nodes over a multihop, wireless sensor network. Deluge builds from prior work in density-aware, epidemic maintenance protocols. Using both a real-world deployment and simulation, we...

An ad-hoc wireless sensor network-based system is presented that detects and accurately locates shooters even in urban environments. The system consists of a large number of cheap sensors communicating through an ad-hoc wireless network, thus it is capable ...

In this paper, we present Deluge, a reliable data dissemi-nation protocol for propagating large amounts of data (i.e. more than can fit in RAM) from one or more source nodes to all other nodes over a multihop, wireless sensor network. To achieve robustness to lossy communication and node fail-ures, we adopt an epidemic approach. Representing the da...

This paper presents a sentry-based approach to power management in wireless sensor networks for applications such as intruder detection and tracking. To minimize average power consumption while maintaining sufficient node density for coarse sensing, nodes are partitioned dynamically into two sets: sentries and non-sentries. Sentry nodes provide suf...

Note This memo documents a part of TinyOS for the TinyOS Community, and requests discussion and suggestions for improvements. Distribution of this memo is unlimited. This memo is in full compliance with TEP 1. Abstract This TEP describes the structure and implementation of the TinyOS 2.x link layer abstractions. The architecture is designed to allo...

ABSTRACT A number of multi-hop wireless reprogramming systems have emerged for sensor network retasking but none of these sys- tems support a cryptographically-strong, public-key-based system for program authentication or any form of recovery from authenticated, but Byzantine, programs. The tradi- tional techniques for authenticating a program and...

Abstract, On August 30, 2005, we successfully demonstrated a large-scale, real-time, surveillance and control application on a wireless sensor network. The task was to track multiple human targets walking through a 5041 square meter sensor field and dispatch simulated pursuers to capture them. We employed a multi-target tracking algorithm that was...

ó Our geometry-independent bulk data dissemination protocol, Deluge, has been found to suffer from slower propagation in the central areas of a wireless sensor network due to hidden-terminal collisions caused by increasing neighborhood size, and consequent effects on timing and sender sup- pression. Using simulation, we investigate whether modicati...