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Course Project Book (Mobile Computing and Wireless Networks) CS 395T – Spring 2001

Course Project Book (Mobile Computing and Wireless Networks) CS 395T – Spring 2001. Course Instructor: Dr. Yongguang Zhang (ygz@cs.utexas.edu) Course URL: http://www.cs.utexas.edu/users/ygz/395T May 16, 2001. Project List Mobile IP service for ACES and TAY Location Service for Mobile Device

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Course Project Book (Mobile Computing and Wireless Networks) CS 395T – Spring 2001

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  1. Course Project Book(Mobile Computing and Wireless Networks)CS 395T – Spring 2001 Course Instructor: Dr. Yongguang Zhang (ygz@cs.utexas.edu) Course URL: http://www.cs.utexas.edu/users/ygz/395T May 16, 2001

  2. Project List Mobile IP service for ACES and TAY Location Service for Mobile Device Linux Kernel Support for Ad-hoc Routing Linux Kernel Module for Ad-hoc Routing Multi-Mode TCP for Wireless Networks Equation-Based TCP Window Adjustment TCP Performance for Ad Hoc Networks Ad Hoc IP Routing over Bluetooth Scatternets Scalable DNS for Mobile Computing Active Ad Hoc Networking Energy-Aware Routing in Ad Hoc Networks Transparent Migration of Mobile Agents Service Discovery in Wireless Networks

  3. Mobile IP service for ACES and TAY • New Ideas • Achieving smooth handoff while roaming between different 802.11 wireless LANs operated in infrastructure point mode using mobile IP. • Algorithm to determine change of network • Guessing the network change based on three missed beacon (registration request). • Guessing network change based on signal strength • Based on users input • Project Goals • Implement & deploy of Mobile IP in CS Network. • Determining best location for home agent and foreign agent. • Study best mode of operation for mobile node (co-located COA or FA assigned COA) to achieve smooth handoff. • Auto configuration of mobile node when network change is detected. • Results/Lesson Learned • Experimental Mobile IP is operational in CS Network • Our Algorithm helped to achieve semi-smooth handoff while moving between ACES and TAY wireless network (30 sec approx). • Lesson learned: • 802.11 does not have good support for mobile IP smooth handoff in infrastructure mode. • No easy heuristics to determine network change (layer2) in 802.11 access point mode. Project team: Madhusudan Kayastha, John Thomas URL: http://www.cs.utexas.edu/users/john/mobileIP.html

  4. Location Service for Mobile Device • New Ideas • Increasing proliferation of 802.11 base stations and PC card  use 802.11 wireless LAN infrastructure to determine mobile device location inside building • Signal strength can be measured and there is a correlation between signal strength and distance • Signal strengths from multiple base stations can triangulate the exact location • Key Design/Approach • Data collation: mapping the service area in advance for an accurate signal map • Algorithm 1: best matching: O(n2) • Algorithm 2: multidimensional search O(log(n)) • GUI (see above) • Limitation : Placement of Base stations limited to certain locations • Results/Lesson Learned • Implemented in Linux • Tested in ACES 6th floor • Beacon stations: 2 • Service granularity: 10 feet • Accuracy: 90% of the time: within 15 feet • Lesson learned: • 802.11 Linux driver does not support “promiscuous” mode to pick up beacons from multiple base stations • Resolved to ad-hoc mode Project team: Ravishankar Chamarajnagar, Jeff Napper URL: http://www.cs.utexas.edu/users/ravshank/mobile_project/project.html

  5. Linux Kernel Support for Ad-hoc Routing • New Ideas • Many Ad-hoc Routing Protocols Exist • Very few real implementations • High Complexity • Not enough tools for development • Performance claims based on simulation results • Designed and developed a generic infrastructure • Provides a tool to evaluate Ad-hoc protocols NIM: Network Interface Module UIM: User Interface Module AKM:Ad-hoc Kernel Module AUD: Ad-hoc User Daemon ART: Ad-hoc Routing Table • Design • Generic Interface for all ad-hoc routing protocols • Network Interface Module (NIM) • User Interface Module (UIM) • NIM: Interface to Network Stack • AKM: In Data Plane • Forwarding according to Ad-hoc protocol • UIM: for data and control plane comm’n. • AUD: In Control Plane • Ad-hoc Route maintenance • Implementation & Testing • Implemented in Linux 2.4.3 • Used Netfilter & IPTable support • Tested multihop routing • Three hosts in broadcast setup • Test Protocols: • Manual Configuration • AODV • Can be extended to support multiple protocols simultaneously Project team: Puneet Chopra, Sumit Garg, Sugat Jain URL: http://www.cs.utexas.edu/users/puneet/mobcomp/proposal.html

  6. Linux Kernel Module for Ad-hoc Routing • New Ideas • Provide an architecture for ad hoc routing protocol implementation by extracting the common part, like multihop for packet delivery, reliable link layer maintenance, etc into general kernel module. • Design • Function separation between user and kernel; • Necessary communication overload between user and kernel are reduced to minimum; • Implementation & Testing • Kernel on top of Linux 2.4.2; • Two hosts can talk to each other; • Communication between user and kernel are tested; • AODV user daemon implemented • Other protocol implementation are extendable Project team: Zhenxun Xiao, Wei Li, Minesh Shilotri URL: http://www.cs.utexas.edu/users/liwei/AdHoc/

  7. Multi-Mode TCP for Wireless Networks • Motivation • TCP has been tuned to traditional networks comprising wired links and stationary hosts • Wireless overlay networks • Heterogeneous overlays • User mobility: vertical handoffs • Sudden, frequent, and significant changes in bandwidth and delay • Study TCP behavior over wireless overlay networks and improve its performance • New Ideas • TCP manages multiple modes • A mode is a subset of entire TCP state • corresponds to an overlay network • dynamic • TCP is notified of the handoff events • TCP switches between modes when the mobile host vertical handoffs between different overlay networks • Different actions for upward and downward handoffs • Key Design/Approach • A mode includes cwnd, ssthresh, rtt, srtt, rttvar, rtxcur, etc. • Generally, save the current mode and load a new mode for a vertical handoff • Schedule a handoff timer for a downward handoff to avoid fast retransmission caused by out-of-order delivery • Reset mode for an upward handoff to an unvisited overlay network • An extension to New-reno TCP • Results/Lesson Learned • Implemented in ns2 • Simulation results in ns2 • Eliminate unnecessary retransmissions caused by timeouts or duplicate acks • TCP goodput improved (> 7%) • Lesson learned: • Implementation of TCP stack • Limitation of the simulation • Need of more realistic experiments Project team: Fengfeng Tu, Hongxia Tian URL: http://www.cs.utexas.edu/users/ftu//project.html

  8. Equation-Based TCP Window Adjustment • Problem • Packet corruption caused by wireless transmission • Caching and retransmission at base station. • Each node in ad hoc network doesn’t have enough resource. • Link failure due to mobility • Explicit notification — freeze TCP states until new route found. • Old states may not be appropriate for new route. • Design • Objective: fast estimation of congestion window size • Node i keeps its own congestion loss rate pi • TCP packet has an additional field, FP (Forwarding Probability). • FP is initially set to 1 , and multiplied by 1-piat each intermediate node i. • Receiver reports FP to the sender with ACK. • Congestion window is calculated from the path loss rate p = 1-FP: • Results 1 • Results 2 Project team: Min Sik Kim, Eunjin Jung URL: http://www.cs.utexas.edu/users/minskim/mobile/

  9. TCP Performance for Ad Hoc Networks • Problem • What is the performance of TCP over an ad hoc network, under each of the four ad hoc network routing protocols? • DSR • AODV • DSDV • TORA • Simulation Setup • Using NS2 • 20 mobile nodes • 500x500 grid • 6 different levels of moving speed • Single and multiple connections traffic pattern • Results • Conclusion • DSR and DSDV is the best • AODV is not as good • TORA is far worst Project team: Feng Wang, Zhiwei Lin URL: http://www.cs.utexas.edu/users/wangf/manetcp.htm

  10. Ad Hoc IP Routing over Bluetooth Scatternets • New Ideas • A new architecture for IP networking in bluetooth scatternet • Current standard (LAN profile, BNEP) does not tackle inter-piconet IP networking issue • Cluster-based on-demand routing strategy • Master Relay Switch Routing (MRSR) protocol for inter-piconet IP forwarding • Key Design/Approach • IP networking for bluetooth scatternet • Piconet bridging scheme • Each scatternet as one IP network • Host based addressing • Master Relay Switch Routing (MRSR) • Ad-hoc routing in scatternet • based on AODV • Results/Lesson Learned • Implemented in NS2 • Extension to IBM BlueHoc Project team: Sidharth Choudhury, Anupam Rastogi URL: http://www.cs.utexas.edu/users/sidharth/report

  11. Scalable DNS for Mobile Computing • Motivation • Using DNS as location service infrastructure for mobile computing • Dynamic updates are already defined in RFCs • No caching? • Scalability? • DNS Workload Analysis • 4.5% in number, 0.8% in bandwidth • 80% absorbed at client cache • 70% absorbed at name servers • 94% absorbed by cache • Problem if no cache • Key Design/Approach • Results/Lesson Learned • Importance of smart caching scheme • Scalability of DNS can be achieved from server replication. • Update individual hosts instead of zones Project team: Dong-Young Lee , Bong-Soo Sohn URL: http://www.cs.utexas.edu/users/bongbong/mobile

  12. AODV TORA Active Ad Hoc Networking AODV • New Ideas • Dynamic Ad Hoc Routing Protocols implemented in an active networking test-bed • Dynamic Protocol Dissemination using mobile code • Provides Increased adaptability to unpredictable Ad Hoc environment DSR AODV DSR PLAN TORA TORA Active (FastNet) Node Active (FastNet) Node PLAN Remote Evaluation DSR Code Pushing Active (FastNet) Node • Key Design / Approach • DSR(basic, optimized, multipath), AODV, and TORA protocols implemented • Node Resident Service functions for basic protocol operations (coded in Popcorn) • Protocols (really mobile glue code) implemented in PLAN • Dynamic Linking of protocol modules • Limitation: • Due to lack of concurrency in FASTNet, only Route Discovery protocol is implemented. Route Maintenance is emulated. • Results / Lessons Learned • Implemented in FASTNet & PLAN (Linux) • Choose routing protocols adaptively. • Lessons learned: • AN can provide dynamic & efficient routing protocols for MANET • Decision-making mechanism for optimal protocol in each environment is needed • Need to extend this idea in test-bed system Project team: Seong-Kyu Song, Stephen Shannon URL: http://www.ece.utexas.edu/~shannon/CS395T.htm

  13. Energy-Aware Routing in Ad Hoc Networks • Motivation • Mobile nodes are battery-operated and one or several nodes’ energy exhaustion may cause the disruption of the entire network • A number of approaches focus on minimizing the total consumed power. • Several approaches’ goal was to maximize the life time of the system. However, these are based on static topology and given traffic demands in advance. • Our goal is to propose energy-aware routing algorithms in dynamic ad hoc network environments to achieve max. system lifetime. • Routing Algorithms • Maxmin routing algorithm – choose the path whose minimum energy level node has the maximum value among all paths. • Maxmax routing algorithm – choose the path which has maximal residual energy on the path • Maxavg routing algorithm – choose the path which has maximal average energy level • Shortest path routing algorithm – no energy consideration • Simulation Setup • Single source-destination pair without node mobility • Single source-destination pair with node mobility • Multiple source-destination pairs without node mobility • Multiple source-destination pairs with node mobility • Introduction of energy balance factor which represents the heterogeneity of initial energy level at each node • Results/Lesson Learned • Overall our Maxmin algorithm performs well. • One example of results: • Simulation techniques such as generating topology and random traffic etc. • Obtain a research trend of energy-aware design in mobile computing environments Project team: Jangwon Lee & Xiangying Yang URL: http://www.ece.utexas.edu/~yangxy/395T.htm

  14. agent source code javac transparent migration with RMI agent byte-code parser agents agent byte-code with support for mobility server Transparent Migration of Mobile Agents • New Ideas • Transform mobile agent byte-code to support transparent migration • Simulate thread and stack frame to support saving and restoring call stack and local variables • Mechanism for surviving migration failure which provides more reliable disconnected operation • Design/Approach • Provide a Java mobile agent system that supports transparent migration • Use standard JVM to gain better acceptance • Use byte-code instead of source code • Results/Lesson Learned • Developed API, parser, and server for mobile agent programming and deployment • With transparent migration, mobile agent programming is more intuitive • Demonstrate typical mobile agents applications using our framework Project team: Endi S. Dewata, Kiran K. Adduri URL: http://www.cs.utexas.edu/users/endisd/mobile

  15. Service Discovery in Wireless Networks • New Ideas • A Jini-based Multimedia Services Application designed for ad hoc wireless systems. • Use of multicast-based service discovery protocols for multimedia services in ad hoc wireless networks. • Adapt to changes in bandwidth in wireless overlay networks. • Provide value-added services to roaming users with minimal configuration. • Integrated user accountability for services. Lookup Service Multicast in a Jini-enabled wireless network Java-based Client GUI Multimedia Provider Service URL Microsoft Access SQL, JDBC • Key Design / Approach • Component-based technologies. • Multimedia Services Application: • Multimedia Client: Plays multimedia files from Service URLs using JMF. • Multimedia Service Provider: Provides Service URLs to clients, interfaces to user database. • Reggie (The Service Lookup by Sun Microsystems): Keeps track of available services. • User Database (Microsoft Access connected to Service Provider via ODBC and JDBC) • Results / Lessons Learned • Service discovery is crucial in emerging packet-based wireless technologies (3G/4G, Bluetooth) • Lessons learned: • Holding users accountable for using wireless bandwidth for value-added services is necessary. • Key challenge: Integrating various enabling technologies (Jini, JMF, JDBC, etc.) Project team: Dogu Arifler, Vivek Sharma URL: http://www.ece.utexas.edu/~arifler/CS395T/index.htm

  16. 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

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