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Course Project Book (Mobile Computing and Wireless Networks) CS 395T – Spring 2002. Course Instructor: Dr. Yongguang Zhang (ygz@cs.utexas.edu) Course URL: http://www.cs.utexas.edu/users/ygz/395T-02S May 17, 2002. Project List Shruti : Session Migration Intelligent Routing Decisions in AODV
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Course Project Book(Mobile Computing and Wireless Networks)CS 395T – Spring 2002 Course Instructor: Dr. Yongguang Zhang (ygz@cs.utexas.edu) Course URL: http://www.cs.utexas.edu/users/ygz/395T-02S May 17, 2002
Project List Shruti : Session Migration Intelligent Routing Decisions in AODV Security in Ad-hoc Networks Secure Group Management in Ad-hoc Network UBQuards: A Smartcard Project Smart Cards: Career Fair Experience Content Based Routing on Ad-Hoc Networks A New Service Discovery Protocol for MANET Comparison of Energy-Aware Ad-hoc Routing Multi-Mode TCP
TCP Personal IP IP Shruti : Session Migration • Challenges Faced, Lessons Learnt • Modifications to legacy applications • Maintaining portability • Implementation & Integration • 32-bit IP insufficient for unique PK abstraction that combines security and authentication • Pre-publish or perish • http://www.cs.cmu.edu/~softagents/migsock/MIGSOCK-ThesisPresentation.ppt Application App State Network level To other end host • Design/Approach • Application layer • Application API to get/set application state • Session Manager daemon • Provides interaction between Home Agent and all user state • Home Agent • Stores the user’s session state • Socket Migrator • Uses IP redirection to offer same abstraction • Transfers TCP state • Future work • Migrate • Other applications (mp3, ram) • User Mode Linux • Bosch virtual machine simulator • Application layer • Use condor style-checkpointing • Create new language abstractions • Home agent using smartcard Project team:Amit, Amol, Ravi, Deepak, Divya, Young-Ri URL: http://www.cs.utexas.edu/users/amitji/utOnly/Shruti.html
Intelligent Routing Decisions in AODV • New Ideas • Using signal strength values to predict the link life time and hence stability of a route • Choose more stable routes • Maintaining multiple paths for a destination • Decreases route discovery latency • Reduce the effect of route failures • Key Design/Approach • Figure out how to measure life time of a link • Use Friis law to predict the relative position of a neighbouring node • Keep a secondary routing table • If primary route fails, use secondary route • If both routes fail, initiate route discovery • Implementation Issues • Simulated these extensions on ns-2 • Experimented with varying parameters • Optimum Beaconing Interval • Dynamically adjust wait time at destination • Performance comparison with base AODV • Used Different mobility patterns of pause time and speeds • Results/Lesson Learned Project team: Gokhan Uluderya, Jared G. Boone & Ashish Ahuja URL: http://www.cs.utexas.edu/users/uluderya/MWNET/project.html
Security in Ad-hoc Networks • Paper Themes Surveyed • Group key establishment • Password-authenticated • Unauthenticated • Threshold cryptography • Secret sharing • Distributed cryptographic operations • Web of trust • “Introducers” • Algorithms Implemented • Password-authenticated group key establishment • Threshold cryptography shared secret division by trusted party, then recollection by clients • Key Design/Approach • Provide a broad reading list for research in the area • Leverage existing work in security for basis of solutions • Adapt existing algorithms to ad-hoc networks • Utilize existing toolkits for cryptographic algorithms • Results/Lesson Learned • Implemented in Java • Used Java Cryptographic Extensions (JCE) • Sun’s JCE provider for Triple-DES • BouncyCastle.org’s for AES and RSA • Lesson learned: • Many existing security solutions are unsuitable due to lack of on-line server or predefined hierarchy • We must assume a prior context Project team: Kevin Kane URL: http://www.cs.utexas.edu/users/kane/395T-02S/
Secure Group Management in Ad-hoc Network • Motivation • Security in ad hoc networks is a necessity. • Not many simulations or implementations for security have been done in ad hoc networks. • Centralized approach is not suitable. • Investigate a distributed solution for key management. • Architecture • Works on top of existing routing protocols. • Simulation Results • Conclusion • Has clear advantage in terms of connection time against the centralized approach. • Need further optimization to adapt frequent topology changes. Project team: Chun-Chi Chen, Edwin Ng, Chwan-Ming Wang URL: http://www.cs.utexas.edu/users/ccchen/classes/cs395t-mwc/proposal.html
UBQuards: A Smartcard Project • New Ideas • Specification for using smartcards as the medium for ubiquitous web services • User state information on card • stateless web service servers • Web service workflow description • Hardware/Software specification for universal communication module CM Cardlet Device Web Service • Key Design/Approach • Web service language interpreter • Run as a Cardlet • 32K Javacard, Stripped down JVM • 1 input, 1 output instruction set • only integer types • control flow using predicates • Communication Module • Consumer Device • Web Services • Microsoft.NET Platform, SOAP • Results/Lesson Learned • Proof of Concept • Smartcards + Ubiquitous • Software Implementation • Ubiquitous Communication Module • USB, HTTP/SOAP, WFDL • Smartcards Computing Power Increasing • Example Scenario • Plug-n-Play Internet Capability • Communication, Storage, “device stuff” completely detached. Project team: Changkyu Kim, Karu Sankaralingam, Youngin Shin URL: http://www.cs.utexas.edu/users/karu/mobile/
Smart Cards: Career Fair Experience • New Ideas • Current literature focuses on the security aspect of smart cards • Exploit smartcards for personalization • Saves effort and more efficient and easier for students and recruiters • Recruiters anyway have to “scan” the resume into the database • Design/Approach • VB front end for sending/receiving resume • Resume and BizCard in XML format • Standardized format and parsing • Applet on smart card has a simple parser • Students have an interface to personalize the data they want from recruiter • Implementation platform: • SLB 4.1 toolkit and REFLEX 72 card reader • Metrowerks CodeWarrior IDE for debugging and simulator on Windows 2000 platform • Results and Future work • Challenging to program with limited data types and memory • Developed prototype to demonstrate simple processing on and off the card. • Smart cards still not ready • Memory too low, (use compression on host side), garbage collection (Java Card) • Tool kit unstable and Simulator not very reliable • Few data types, array of objects or 2-D arrays not available Project team: Kaushik Lakshmanan and Ramanathan Pallassana
P2P App Agent Content Requested Content Routing Agent 1 1 LL 1 MAC Reply with Content Channel Content Based Routing on Ad-Hoc Networks • Motivation • Peer-to-peer applications : content driven • No centralized DNS for name-lookup in MANETs • Current protocols have to decouple steps of name to address mapping and route discovery • Combine! -- Content based routing • Key Ideas/Design • Nodes maintain information if they are on a path towards content • Communication : local broadcast • Associate a path-id with every path discovered • Eliminate IP-Address/node-id • For optimization :use pseudo random local-id • Distance metric : hop count • Results/Lesson Learned • Implemented in NS2 • Comparison • Plain flooding vs Our Content-Routing • Metric • Traffic : over 80% reduction • Route cache hit rate : about 27% • Control traffic : negligible • Lesson learned: • Think out of the box • challenge to implement a whole new protocol in ns Project team: Vivek Subramanian & Amish Gandhi URL: http://www.cs.utexas.edu/users/viveksub/mobile_proj.html or http://www.schmoogle.com
A New Service Discovery Protocol for MANET • New Ideas • Distributed directory • Cache optimizations (ala DSR, AODV) • Periodic Broadcast based Service Advertisement. • Transparent to underlying routing protocols • Each node serves as a Service Agent, Directory agent and also User agent Master Application MANET Agent API Service Agent Slave AdHoc Tool Kit Environment • Motivation • Service Discovery will become a crucial need for upcoming networks/devices for seamless interoperability • Existing Protocols • JINI, UPNP, SLP, Salutation, etc.. • Existing protocols are unsuitable for Mobile AdHoc Networks • We Propose and implement a new SDP for MANETs. • Results/Lessons Learned • File Sharing Application implemented in java • Tested using AdHoc toolkit • Used Socket Library extension to emulate the mobile environment • Lessons learned: • Using AdHoc toolkit • Various SDPs Project team: Krupakar V. Pasupuleti, Jisun Park and Subramanyam Mallela URL: http://www.cs.utexas.edu/users/manyam/cosd.htm
Comparison of Energy-Aware Ad-hoc Routing • Motivation • Important to ensure battery-operated mobile nodes operate as long as possible. • Several solutions proposed and compared with non-energy-aware protocols. • Our goal is to compare different solutions under DSR using same parameters. • Algorithm • Span: Only “coordinator” nodes stay awake. The “non-coordinator” nodes go to sleep. • Afeca: Sleep depending on the number of transmitting neighbors. • FA: Choose the minimum cost routing path. • DSR • Simulation Setup • Use the ns-2 simulator. • Parameters: traffic load (number of source nodes and traffic rate), mobility (pause time, speed). • Matrices: Packet delivery rate vs. traffic load, packet loss rate vs. mobility, network lifetime vs. traffic load, network lifetime vs. mobility, nodes survival percentage vs. time. • Results/Lesson Learned Project team: Pisai Setthawong, Hari Shankar, Yihong Zhou URL: http://www.ece.utexas.edu/~pisai/cs395t
Multi-Mode TCP • MM-TCP • When the bandwidth of bottlenet changes frequently, TCP can save a subset of current TCP states (mode). • When TCP return to a history network enviorment, it can use the saved mode to set some initial values, such as cwnd. • TCP can adapt the enviorment quickly and then improve the performance. ... ... • Experiment Result • Conclusion/Lesson Learned • Implemented in ns2 • Simulation results in ns2 • There are some improvements when TCP switches between different network enviorment. But the improvement is not large enough. • Lesson learned: • Implementation of TCP stack • Simulation an evaluation Project team: Yi Li URL: http://www.cs.utexas.edu/users/ylee/project.html
Contact Prof. Yongguang Zhang Dept. of Computer Sciences University of Texas at Austin Austin, Texas 78712, U.S.A. E-mail: ygz@cs.utexas.edu Phone: 512-232-7889