May 8-12, 2006
Rutgers University
Core Building
301 (Core A)
Busch Campus


Monday, May 8
Keynote Address: Future Trends in Wireless Technology and the Path to Pervasive Computing - Dr. Dipankar Raychaudhuri (WINLAB Director, Rutgers University)
Wireless systems are evolving from today's centrally managed cellular and WLAN services towards ad-hoc heteregeneous networks capable of supporting a broad new class of "pervasive computing" applications. We discuss some of the technical challenges associated with building pervasive systems which involve real-time, opportunistic and ad-hoc communication between low-power embedded wireless sensors/actuators and computing devices within the Internet. Selected enabling technologies for this pervasive computing scenario are discussed, including the infostation (wireless cache), multimodal wireless sensors, self-organizing ad-hoc network protocols, and cognitive radio. The talk concludes with some examples from related proof-of-concept prototyping projects and the ORBIT wireless network testbed under development at WINLAB.
Dipankar Raychaudhuri is Professor, Electrical & Computer Engineering Department, and Director, WINLAB (Wireless Information Network Lab) at Rutgers University. As WINLAB's Director, he is responsible for a cooperative industry-university research center with focus on next-generation wireless technologies. WINLAB's current research scope includes topics such as RF/sensor devices, UWB, cognitive radio, ad hoc mesh networks, wireless security, future 4G/WLAN systems, and pervasive computing. He is also principal investigator for the NSF-funded "ORBIT" open-access next-generation wireless network testbed now under construction at Rutgers. He has previously held progressively responsible corporate R&D positions in the telecom/networking industry including: Chief Scientist, Iospan Wireless (2000-01), Assistant General Manager & Dept Head-Systems Architecture, NEC USA C&C Research Laboratories (1993-99) and Head, Broadband Communications Research, Sarnoff Corp (1990-92).

Dr. Raychaudhuri obtained his B.Tech (Hons) from the Indian Institute of Technology, Kharagpur in 1976 and the M.S. and Ph.D degrees from SUNY, Stony Brook in 1978, 79. He is a Fellow of the IEEE.
Binary Serialization of XML for Small Devices - Jaakko Kangasharju (University of Helsinki, Finland)
XML has in recent years become a ubiquitous format on the Internet, but it has not been popular in pervasive computing due to its much higher processing and transmitting costs compared to system-specific binary formats. A recent popular trend is to replace XML with an alternate, so-called binary XML, format. We cover here the most important techniques used in such formats, both general-purpose techniques applicable to any XML as well as schema-based techniques that require a schema to be available, emphasizing our own format designed for mobile devices. We provide relevant measurements on different binary XML implementations and also discuss some disadvantages of binary XML formats.
File Synchronization with Syxaw in an Ad Hoc Network (Work-in-progress Report) - Tancred Lindholm (University of Helsinki, Finland)
We describe the ongoing work on extending the Syxaw file synchronizer for mobile devices towards operation in an ad-hoc networked environment. We describe how the hierarchical sharing model based on synchronization links may be utilized and how the Syxaw versioning model may be extended to suit this environment. We also describe how the Syxaw synchronization protocol may be adapted to other transports than HTTP (e.g. Bluetooth), and what type of service discovery infrastructure will be needed to enable transparent switching of synchronization peers.
Mobility Control for Throughput Maximization in Ad Hoc Networks - Dr. Tamer Nadeem (Siemens)
Physical topology of an ad hoc wireless network imposes fundamental limits on its throughput capacity. In this work, we present a network design algorithm for configuring node locations in an 802.11 ad hoc network with the goal of improving the throughput capacity of the network. Given a network configuration (i.e., a mapping of network nodes to physical locations), we establish an inverse proportional relationship between the interference degree of the network and the guaranteed link-throughput. Motivated by this observation, we present an algorithm which progressively guides the network towards better configurations with lower interference degrees, which in turn increases the network.s throughput capacity. Packet level simulations using the NS-2 simulator shows that the reconfigured topologies obtained by our algorithm consistently outperform the original network topologies for throughput and delay related metrics. In particular, for many cases, we observed over 100% increase in the total network throughput and the minimum guaranteed throughput, over 60% increase in throughput fairness and over 50% reduction in the mean-service delay of packets. Our algorithm admits a simple distributed implementation and can be viewed as a distributed mobility control primitive for improving the throughput performance of mobile ad hoc networks. Alternately, our techniques can also be employed by a centralized designer during network creation time to obtain a network configuration with a high throughput capacity. To the best of our knowledge, ours is the first work which explores the use of guided network configuration strategies for improving the throughput capacity in ad hoc wireless networks.
Suppressing Attacks at the Originators: Trusted Remote Policy Enforcement in Ad Hoc Networks - Gang Xu (Rutgers University)
Typical ad hoc networks lack the capability to prevent attacks from malicious nodes because new nodes are allowed to establish wireless links to existing members in order to support dynamic cooperation. After establishing a data link layer connection, a malicious node can further obtain access to the network and above layers in the protocol stack. Current solutions try to solve this problem by allowing the .good. nodes to react to attacks. The main drawback of such solutions is that the damage might be already done at the time when the attacks are detected. This paper proposes a method to prevent the attacks from reaching the network by suppressing them directly at their originators. Our method allows an initial group of nodes to define a common network access control policy. Consequently, it downloads and enforces this policy on each new node before the node establishes a link layer connection to the network. A trusted agent based on the Trusted Platform Module (TPM) specified by the Trusted Computing Group (TCG) ensures that the execution of all the programs involved in the policy enforcement cannot be tampered with. A prototype implementation based on an IEEE 802.11 ad hoc network demonstrates the feasibility of the proposed method as well as its low overhead.
Tuesday, May 9
Fuego Event Service: Towards Modularity in Event Routing - Sasu Tarkoma (University of Helsinki, Finland)

The Fuego event service was developed in the Fuego Core 2002/2004 project. The event service addresses the challenges in the mobile computing environment by providing an asynchronous content-based publish/subscribe system that supports client mobility. A key component of the architecture is the Fuego event router, which connects the publishers and subscribers and mediates event messages between them. The Fuego router consists of a number of new data structures for filter-based routing tables that can be configured for different environments. In this paper, we present an overview of the system and examine the modular router building blocks.

Distributed Optimization in Networks - Elisa Schaeffer (University of Helsinki, Finland)
We study network optimization tasks in distributed settings using limited or no global information on the network topology or the current value of the fitness function. Possible applications include maximizing of lifetime in battery operated networks, minimizing total duration in load-balanced computation, etc. We review existing literature and explore ideas for original work drawing from the field of complex nonuniform networks.
Information Flow Control for Location-Based Services - Nishkam Ravi (Rutgers University)
Sharing private information while preserving privacy is a challenging task. Currently existing information-flow control models preserve privacy by isolating public data from private data. Data isolation, however, is not applicable to many real applications. We present a new model for information-flow control called Non-Inference. Non-inference allows public data to be derived from private data, but requires that the adversary should not be able to infer the value of private data from public data. We show how it can be enforced using static program analysis in the context of location privacy.
Privacy of Anonymous Location Sampling Techniques: A Traffic Monitoring Case Study - Baik Hoh (Rutgers University)
Automotive traffic monitoring belongs to a class of applications that collect aggregate statistics from the location traces of a large number of users. Since the individual's identities need not be known, anonymization of records appears suitable to address the privacy problem. In this paper, we show, however, that known clustering and tracking techniques can reconstruct private information from such anonymous traces. To address this problem, we then propose privacy algorithms to control the release of location traces and show that these can guarantee a high degree of privacy while providing sufficient quality of service for traffic monitoring applications.
A Multipath Routing Architecture for Background Transfers - Aniruddha Bohra (Rutgers University)
Background transfers, i.e., non-interactive bulk data trans- fers that humans are not actively waiting on, dominate In- ternet traffic today. Examples include peer-to-peer cycle shar- ing, content distribution, remote backup and software up- dates. Today's best-effort Internet does not distinguish be- tween regular (foreground) and background transfers. Conse- quently, background transfers can interfere with foreground transfers and cause longer wait times, thereby hurting hu- man time and productivity. To address this problem, several end-host based protocols such as TCP-Nice, TCP-LP, etc. have been proposed recently to provide lower than best-effort service.
In this talk, we present the design and implementation of a background network (Harp), and an associated congestion control algorithm to harness spare capacity for bulk transfers. Compared to end-host based protocols, network support en- ables three distinguishing features. First, Harp uses multiple paths to exploit the path diversity and load imbalance inher- ent in today's Internet. Second, its resource allocation has provably better fairness and utilization compared to a uni- path end-host based protocol. Finally, it is readily deploy- able as it requires no modification to end-hosts.
Byzantine Fault Tolerant Public Key Authentication in Peer-to-Peer Systems - Vivek Pathak (Rutgers University)
We describe Byzantine Fault Tolerant Authentication, a mechanism for public key authentication in peer-to-peer systems. Authentication is done without trusted third parties, tolerates Byzantine faults and is eventually correct if more than a threshold of the peers are honest. We will addresses the design, correctness, fault tolerance, and performance of authentication over insecure asynchronous networks. We propose to implement a sender authentication mechanism for securing electronic mail. Sender authentication has been used as a tool for protecting against spam and phishing attacks. We compare this proposal against other authentication based spam control proposals in terms of attack resistance and overhead.
Wednesday, May 10
Outdoor Distributed Computing - Dr. Cristian Borcea (New Jersey Institute of Technology)
The next generation of computing systems will be embedded everywhere in the physical world and will penetrate every domain of our daily life. These systems, deployed in a virtually unbounded number and dynamically connected, will form ad hoc networks of embedded systems. Developing services and applications on top of this huge ubiquitous computing environment is constrained by the lack of proper programming models and system support to address its volatility, heterogeneity, and scale.
This talk will present Spatial Programming and Smart Messages, a programming model and its corresponding system architecture for outdoor distributed computing. Spatial Programming is a location-aware programming model that enables programmers to easily develop distributed applications over dynamic networks of potentially mobile embedded systems. To support Spatial Programming, we have used Smart Messages, a system architecture based on execution migration and self-routing. To demonstrate the feasibility of the proposed solutions, we have built a prototype system and a few outdoor distributed applications executed on top of ad hoc networks of PDAs.
Context-Aware Migratory Services in Ad Hoc Networks - Oriana Riva (University of Helsinki, Finland)
Ad hoc networks can be used not only as data carriers for mobile devices, but also as providers of a new class of services specific to ubiquitous computing environments. Building services in ad hoc networks, however, is challenging due to the rapidly changing execution contexts, which often lead to situations where a node hosting a certain service becomes unsuitable for hosting any longer the service execution. We propose a novel model of service provisioning in ad hoc networks based on the concept of context-aware migratory services. Unlike a regular service that executes always on the same node, a migratory service can migrate to different nodes in the network in order to accomplish its task. The migration is triggered by changes of the execution context, and it occurs transparently to the client application. We designed and implemented a framework for developing migratory services. We built TJam, a proof-of-concept migratory service, which predicts traffic jams in a given region of a highway by using only car-to-car short-range wireless communication. The experimental results obtained over an ad hoc network of PDAs show the effectiveness of our approach in the presence of frequent disconnections. We also present simulation results that demonstrate the benefits of migratory services in large scale networks compared to a statically centralized approach.
Extending Component-Based Software Architecture with Context-Awareness and Beyond - Michael Przybilski (University of Helsinki, Finland)
Context-aware systems are beginning to play an important role in modern software systems, especially in software for wireless information devices. However, the research in this field can still be considered to be in its infancy. Systems that support the study of context-awareness are usually built with the specific purpose of the study in mind and it is usually very difficult to extend those systems for other purposes, or to integrate them with existing applications. So far only very few common architectures or suggestions towards the architecture of context-aware systems have been developed. We have been studying the architecture of reasoning systems in context-aware systems and distinguish the two typical steps of learning and inference. These steps can be divided further into several phases, such as data-gathering, preprocessing, feature extraction, feature-selection, classification, etc. Especially in a multidevice environment, the possibility of combining the different phases, ordering them differently and re-using the results achieved on one device, for another device in a similar context can provide major benefits. The reasoning process is more flexible, and using the communication capabilities of the devices enables us to share learned models. It furthermore allows us to use more advanced reasoning algorithms, on remote devices, which have more resources available to them and which can return the results to the local device. We propose a framework that enables us to take advantage of the aforementioned structuring of reasoning mechanisms, as well as the communication capabilities of current mobile devices.
ORBIT: Open-Access Research Testbed for Next-Generation Wireless Networks - Pandurang Kamat (Rutgers University)

ORBIT is a two-tier laboratory emulator/field trial network testbed designed to achieve reproducibility of experimentation, while also supporting evaluation of protocols and applications in real-world settings. The laboratory-based wireless network emulator uses a novel approach involving a large two-dimensional grid of 802.11 radio nodes which can be dynamically interconnected with reproducible wireless channel models.

Designing an Inter-Vehicular Network Stack for Car-to-Car Communication - Pravin Shankar (Rutgers University)
Recent advances in wireless vehicle-to-vehicle (V2V) communication systems enable the development of Vehicular Ad Hoc Networks (VANET) and create significant opportunities for the deployment of a wide variety of vehicular applications and services. However vehicular networks have specific mobility conditions and application requirements that differentiate them from other networks. We propose an inter-vehicular network stack architecture which supports the unique demands of car-to-car communication. The data-link layer makes use of short-range wireless network interfaces (IEEE 802.11) as well as the cellular network (GPRS/3G), and switches between the two based on network conditions and application demands. The data aggregation and validation layer aggregates traffic information based on distance, and validates the information for correctness and timeliness. The Information Query layer enables vehicles to query for information about specific objects or places such as the current road conditions at some driver-specified location. Finally we describe TrafficView, a prototype system, which uses V2V communication to disseminate real-time vehicle position and traffic density information between cars. This is joint work with NJIT and funded by NSF Collaborative Research: NeTS-NBD: (ANI 0520123) grant and NSF Information Technology Research (ANI 0121416) grant.
Friday, May 12
Programming Ad Hoc Networks of Mobile Devices - Dr. Ulrich Kremer and Adrian Stere (Rutgers University)
Ad-hoc networks of mobile devices such as smart phones and PDAs represent a new and exciting distributed system architecture. Building distributed applications on such an architecture poses new design challenges in programming models, languages, compilers, and runtime systems. This talk will introduce SpatialViews, a high-level language designed for programming mobile devices connected through a wireless ad-hoc network. SpatialViews allows specification of virtual networks with nodes providing desired services and residing in interesting spaces. These nodes are discovered dynamically with user-specified time constraints and quality of result (QoR). The programming model supports ``best-effort'' semantics, i.e., different executions of the same program may result in ``correct'' answers of different quality. It is the responsibility of the compiler and runtime system to produce a high-quality answer for the particular network and resource conditions encountered during program execution.
Example applications will be used to illustrate the different features of the SpatialViews language, and to demonstrate the expressiveness of the language and the efficiency of the compiler generated code. Sample applications include sensor network applications that collect and aggregate sensor data within the network, applications that use dynamic service installation and computation offloading, and augmented-reality gaming. A simulation environment allows the execution of SpatialViews programs under different simulated physical conditions. More information about the language, compiler and runtime system, including a distribution of our prototype system, can be found at
Application-Specific Compression for Remote Visualization of Genomics Applications - Lars Ailo Bongo (University of Tromso, Norway)
Sensitive data can be shared by only sharing visualizations. However, smooth remote interaction with the data requires higher bandwidth than practical in a WAN. We describe and present results for compression schemes exploiting redundancy in data transmissions to reduce bandwidth usage.
Towards Automated Detection and Containment of Rootkit Attacks - Arati Baliga (Rutgers University)
Spread of malware is a growing trend in today's increasingly networked world. Worm and virus writing is no longer done only for fun, it is more geared towards profit. A deadly kind of malware called rootkits evades detection and tries to hide it's presence from the administrator. Rootkits often consist of sniffers, log erasers and backdoors to allow the attacker to cover their tracks and retain control of you system remotely. When these are bundled with worms and viruses, they can escape detection from anti-virus software as well. We explore existing solutions to deal with rootkit attacks. We describe a model to detect and contain the effects of a rootkit attack automatically in a virtual machine environment.
FileWall: Implementing File Access Policies Using Access Context - Stephen Smaldone (Rutgers University)
FileWall is a file access control framework that allows file system administrators to enforce file access policies based on dynamic access context such as access history, environment, etc. Similar to a firewall, which interposes on a network path and operates on packets to enforce network access policies, FileWall interposes on a client-server path and operates on network file system messages to enforce file access policies. FileWall does not require any modification to either the file system client or the file server, while minimizing the non-recoverable state. FileWall provides the administrator with the ability to protect file systems, provide quality of service, perform forensic analysis, and other file access policies. In this talk, we present the design, implementation, and evaluation of FileWall.

Admittance to the workshop is free. All are welcome to attend.


Ph.D. Student Workshop on Spontaneous Networking

Talk Abstracts