WorldCat Identities

Xie, Geoffrey

Works: 6 works in 15 publications in 1 language and 357 library holdings
Roles: Editor, Author
Publication Timeline
Most widely held works by Geoffrey Xie
Automated security management by Ehab S Al-Shaer( Book )

8 editions published in 2013 in English and held by 15 WorldCat member libraries worldwide

No back cover copy
A Software Framework for Mobile Ad Hoc Data Communications Using Voice-Centric Tactical Radios( )

1 edition published in 2006 in English and held by 0 WorldCat member libraries worldwide

Currently, small ground units such as those operating in Iraq have very limited data communication capabilities between soldiers. Tactical chat or file transfer is available only at the battalion level or higher. To address this problem, the authors have developed a software application, which can leverage existing voice-centric radios to provide data services including tactical chat and file transfer capabilities to frontline ground units. The software embodies two key innovations: (1) a data link protocol to allow radios to form wireless LANs, and (2) an operation-aware ad hoc routing protocol to support reliable and resource-efficient multi-hop message relays. This paper describes the design, implementation, and functional testing of these two protocols
A Networking Protocol for Underwater Acoustic Networks( )

1 edition published in 2000 in English and held by 0 WorldCat member libraries worldwide

There exists an increasing demand for reliable, high capacity Underwater Acoustic Networks (UANs), as evidenced by the large volume of research invested over the last decade in overcoming the difficulties inherent with propagation of information bearing signals through shallow water regions. Application interests include oceanographic information gathering, environmental monitoring, and coastal defense (anti-submarine and mine/counter-mine warfare). Two specific examples of the recent efforts to develop and field UANs in shallow water regions are the Deployable Autonomous Distributed System funded by the Office of Naval Research (ONR) and the Autonomous Oceanographic Sampling Network sponsored by ONR and the National Science Foundation. The Deployable Autonomous Distributed System (DADS), envisioned to provide undersea surveillance in littoral waters [Rice 2()()()1, is an underwater array of fixed sensor plattorms, interconnected by acoustic modems. The network connects the remote sensor plattorms to a coim%and center through a portal that relays data received from the acoustic network to the distant coim%and facility across satellite links. Acoustic data is propagated through the network over multi-hop coim%unications paths. The individual hops are configured as half duplex code division multiple access links between discrete modem pairs. Messages are relayed between paired platton%s to minimize the transmit power requirements and reduce the impact of tempon%l, spatial, and frequency spreading of the signal as it propagates through the littoral channel
Network Policy Languages: A Survey and a New Approach( )

1 edition published in 2000 in English and held by 0 WorldCat member libraries worldwide

In this report a survey of current network policy languages is presented. Next, a summary of the techniques for detecting policy conflicts is given. Finally, a new language, Path-based Policy Language (PPL), which offers improvements to these is introduced. Previous network policy languages vary from the very specific, using packet filters at the bit level, to the more abstract where concepts are represented, with implementation details left up to individual network devices. As background information a policy framework model and policy- based routing protocols are discussed. PPL's path-based approach for representing network policies is advantageous in that Quality of Service (QoS) and security policies can be associated with an explicit path through the network. This assignment of policies to network flows aids in new initiatives such as Integrated Services. The more stringent requirement of supporting path- based policies can be easily relaxed with the use of wild card characters to also support Differentiated Services and best-effort service, which is provided by the Internet today
Proceedings of the Ninth ACM SIGCOMM Workshop on Hot Topics in Networks by Geoffrey Xie( )

3 editions published in 2010 in English and held by 0 WorldCat member libraries worldwide

Incorporating Realistic Acoustic Propagation Models in Simulation of Underwater Acoustic Networks: A Statistical Approach( )

1 edition published in 2006 in English and held by 0 WorldCat member libraries worldwide

The development of protocols to advance the state of the art in Underwater Acoustic Networks (UANs) relies on the use of computer simulations to analyze protocol performance. It is typical for designers to abstract away much of the detail of the physical environment in order to simplify the development of the simulation and ensure the simulation runtime performance is reasonable. The validity of the simulation results becomes questionable. There are, though, very high fidelity models developed by acoustic engineers and physicists for predicting acoustic propagation characteristics. In addition to these models, empirical data collections have been generated for many geographic regions of interest to UAN planners. However, incorporating these engineering and physics models or data collections into a network simulation is problematic, as the models are computationally complex and the data sets are not directly usable for acoustic signal propagation characterization. This paper presents a statistical method for developing a computationally efficient and simulation friendly approximation of a physics model of path loss. This method may also be used to adapt empirical data sets for use in network simulation in the same manner. The method was applied to the output of the Monterey-Miami Parabolic Equation model to assess its impact on the runtime performance of an OPNET-based simulation. Results of that simulation are compared to results from a previous OPNET simulation that simply used distance to determine reception. The simulation results confirm the incorporation of the MMPE approximation does not noticeably impact the runtime performance of the simulation. Anecdotally, the simulation confirms earlier results the suggest contention based access controls without collision avoidance techniques may outperform the typical access technique adapted from wireless radio networks that employs collision avoidance even in the high load regime, contrary to conventional wisdom
Audience Level
Audience Level
  Kids General Special  
Audience level: 0.49 (from 0.49 for Automated ... to 0.99 for Incorporat ...)

English (15)