Wireless PAN, LAN and MAN研究群 研究能量與研發成果

Members and Research Directions Sensor networks 曾煜棋、陳 健、趙禧綠、王國禎、簡榮宏、易志偉 WLAN 曾煜棋、趙禧綠、王國禎、簡榮宏、曾建超、王協源 Mesh networks WiMax 陳健、趙禧綠、簡榮宏

研發成果

A Cross-Layer Control Scheme for VoIP application over 802 A Cross-Layer Control Scheme for VoIP application over 802.11e Wireless Local Area Networks Cross layer VoIP over 802.11e WLAN Policy based 802.11e Network Motivation: Centralized admission control scheme for 802.11e WLAN. Mechanism Modify RADIUS message to carry Service Level Agreement (SLA) Classification: Classify by client can be simpler than by flow Motivation: Let VoIP adapt to time-varying wireless channel condition. Mechanism Select VoIP codec according to current RSSI Measurement Metrics: One-way delay, Mean Opinion Score (MOS)

Multi-channel hidden terminal problem Hybrid channel assignment A Medium Access Protocol for Multi-Channel Multi-Interface Wireless Mesh Network Multi-channel hidden terminal problem Hybrid channel assignment A 1 Fixed interface Switchable interface B 2 C 3 D RTS CTS Collision DATA Channel 1 Channel 2 Wireless Mesh Network Let APs connect to Internet without wired connection Utilize multi-channel and multi-interface to increase network capacity The 802.11 MAC protocol doesn’t support multi-channel and multi-interface

An Implementation of IEEE 802.16e General Handover Emulator Emulation Topology To implement an IEEE 802.16e emulator for further research and application development. IEEE 802.16d, IEEE 802.16e Implement Components: MAC layer frames Network layer frames Neighbor Table MAC and IP address map Data buffering Data tunneling

A Distributed Time-Slotted Multi-Channel Protocol for IEEE 802 A Distributed Time-Slotted Multi-Channel Protocol for IEEE 802.11 Wireless Mesh Networks Fig. Wireless Mesh Network Motivation The idea of exploiting multiple channels is appealing in wireless mesh networks because of their high capacity requirements to support backbone traffic. Goal To reduce interference of the wireless mesh networks by using multi-channel.

Integrating SIP and IEEE 802 Integrating SIP and IEEE 802.11e to Support Handoff and Multi-grade QoS for VoIP Applications Goal: Guarantee QoS of each admitted VoIP call and achieve early resumption of resources even when handoff occurs. Fairly distribute network resource and improve channel utilization. Analysis Analytical Model: A Y-dimension model. Take transmission rate into consideration. Performance Analysis: Using recursive techniques based on boundary cases. Ex: IEEE 802.11e WLAN (Y=4)

A Push-Based VoIP Service for an Internet-Enabled Mobile Ad Hoc Network An Ad Hoc Network-Based VoIP Service Platform: Integrating MANET and cellular networks, we propose an MANET-based VoIP service platform. Possible Applications: Indoor: home VoIP system Outdoor: provide mobile VoIP service on bus, train…etc. However, connecting cellular networks incurs charges and power consumption. A new node, called push server, is proposed. A push mechanism is developed. System Architecture

Resource Allocation and Packet Forwarding in Multi-radio Multi-mode Multi-channel Multi-rate (M4) Wireless Mesh Networks Much higher throughput Linear Programming Formulation Graph representation M4 wireless infrastructure mesh Utilizing M4 benefits and traffic splitting

Joint Multi-Channel Link layer and Multi-Path Routing Design for wireless Mesh Network A WMN is two-tier architecture: Forming a wireless backbone Providing large coverage Offering strong connectivity Producing high robustness

An Adaptive Quorum-based Mechanism for the Clock Asynchronism Problem in IEEE 802.11 MANETs The Concept of Quorum: Grid-based Quorum Protocol Design:

Adaptive Attenuation Factor Model for Localization in Wireless Sensor Networks Adopting a centralized architecture to localize sensor nodes Dynamically measuring n and X locally to increase the accuracy of localization

An Integrated Call Agent of the Converged VoIP Network Using IN basic call state model (BCSM) Unified event trigger Mapping VoIP message to BCSM Supports: H.323, SIP, MGCP, H.248 Inter domain interworking Components in our ICA ICA functional blocks

A Cluster-based Energy Efficient Routing Algorithm in Mobile Wireless Sensor Networks Step 1. Select one hop neighbor nodes closer to the anchor Energy consumption vs. number of nodes Step 2. Choose the node with the maximum energy level from the selected nodes Latency per packet vs. number of nodes.

An illustration of dwDVS A Deferred-Workload-based Dynamic Voltage Scaling Algorithm for Hard Real-Time Systems An illustration of dwDVS Effect of WCET/BCET ratio on energy consumption Effect of worst-case utilization on energy consumption

A Power Saving MAC Mechanism for VoIP over IEEE 802.11e WLANs VoIP over WLANs system architecture Power saving mechanism in PSM-V

A Power-Efficient MAC Protocol for VoIP Traffic over IEEE 802.11e WLANs PIFS SIFS Beacon QoS CF-Poll QoS Null Data ACK TXOP 1 Controlled Access Phase (CAP) ….. QAP QSTA QSTA 2 .... Contention Period (CP) CAP QSTA 1 Proposed power-efficient polling scheme Polling scheme comparison Scheme Round-robin polling (RRP) scheme [8] On-demand polling (ODP) scheme [4] Power-Efficient Polling (PEP) scheme (Proposed) Characteristics of polling scheme Static Dynamic Complexity of implementation Easy Medium Normalized power consumption Highest Lowest Aggregate throughput Higher Lower Almost the same as RRP Average end-to-end delay

A NEW MODEL FOR OPTIMAL RWA WITH FIXED-LENGTH TUNNEL ALLOCATION IN MG-OXC NETWORKS Bundle a group of consecutive wavelength channels together and switch them as a single unit on a specific route (tunnel) Multigranularity Optical Cross-Connect (MG-OXC) Layered Auxiliary Graph Routing and Wavelength Assignment (RWA) with tunnel allocation Given a set of static lightpath requests, allocate a set of fixed-length tunnels find routes from source to destination nodes, The objective is to minimize the blocking probability.

Fast Packet Classification Using Multi-Dimensional Encoding Solution: Divide rules into several multi-dimensional collision-free rule sets Use these sets to form the new coding vector to replace the bit vector Multi-Dimension Encoding

Minimum-Delay and Energy-Efficient Source to Multisink Routing in Wireless Sensor Networks Problem: Obtain minimum-delay and energy-efficient transmission paths under Single-Source to Multi- Sinks routing scenario in wireless sensor networks Minimum delay, Large energy cost Energy efficient, Large delay Minimum-delay, Energy-efficient

Flow-Bottleneck preprocessing Dynamic Density Cutback SmartBone: An Energy-Efficient Smart Backbone Construction in Wireless Sensor Networks Problem: Energy consumed by awaken sensor nodes Radio interference of awaken sensor nodes raises packet retransmission resulting additional energy consumption Flow-Bottleneck preprocessing Dynamic Density Cutback SmartBone algorithm:

Shared Risk Link Group (SRLG) Diverse Routing and Channel Assignment in Survivable Wireless Mesh Networks SRLG: A SRLG is a group of links share a common channel from a NIC The SRLG groups are {(B, C), (A, C)}, NIC of node C tunes to channel 3 {(B, E), (D, E), (C, E)} , NIC of node E tunes to channel 2 {(B, D), (D, E)} , NIC of node D tunes to channel 1 NIC fail result in failure of all links in the same SRLG group

Fairness under greedy behavior Fair Scheduling with QoS Guarantees for Uplink Transmission in WiMAX Networks 2TSA Operations Fairness Improvement Average throughput Fairness under greedy behavior

Fair Queuing with Power Saving in Wireless Ad Hoc Networks Algorithm flow chart Fairness Power consumption Network life

Asymptotic Distribution of The Number of Isolated Nodes in Wireless Ad Hoc Networks with Unreliable Nodes and Links Main Results: Suppose that and nodes have the same maximum transmission radius r = for some constant ξ. Then the total number of isolated nodes is asymptotically Poisson with mean . Network Topology p1 = 1 and p2 = 0.9

Major Projects ZyXEL Inc.: “802.11e無線網路下的傳輸品質與快速換手之研究 (QoS and Fast Handover in 802.11e WLAN)”, 2005.03-2006.02. 工研院/學研計畫: "Communication Protocols for Wireless Access Networks". (2005.01~2005.12) 後卓越計劃(Program for Promoting Academic Excellence of Universities II), NSC: "Advanced Technologies and Applications for Next Generation Information Networks" 下一世代資訊通訊網路尖端技術與應用(2004.04~2008.03). 分項計畫三: B3G All-IP Wireless Network Technologies, 後三代全IP無線網路技術 分項計畫四: Wireless Ad Hoc and Sensor Networks Technologies, 無線隨意及感測網路技術 國科會: “藍芽個人無線區域網路上通訊議題之設計實作與分析”(2003.08~2006.07) 多天線多通道多模多速率無線網狀網路之設計與實作-總計畫(1/3), NSC, 2005.08至2006.07

Major Projects 多天線多通道多模多速率無線網狀網路之設計與實作-子計畫二:M4無線網狀網路之存取控制協定及繞徑設計(1/3), NSC, 2005.08至2006.07 後卓越計劃(93R045)下ㄧ世代資訊通訊網路尖端技術與應用(二) -子計畫三:後三代全IP無線網路技術, Ministry of Education, 2004.04至2008.03 M4無線網狀網路具品質知覺之無縫交遞(1/3), NSC, 2005.08-2006.07 含行動隨意網的MPLS無線基礎網路, NSC, 2003.08 -2006.07 智慧型手持式裝置雙模網路支援能力之研究與網路應用服務, Institute for Information Industry, 2004.01-2004.12

Major Projects 多階層行動隨意網路之設計及實作-總計劃, NSC, 2003.08 -2005.07 Advanced System Design of Power Aware Mobile Devices, NSC, 2003~2006 Network flow control based Generalized Multiprotocol Label Switching 2 (GMPLS), NSC, 2003~2005

Major Projects A Wi-Max Gateway implementation Using IXP 425, Intel, Taiwan, 2004~2006 Resource Management and Performance Modeling for WCDMA Mobiles - subproject 3: Performance Modeling of Mobile Processor using SystemC, MediaTek Inc., Taiwan, 2004~2005

Prof. Rong-Hong Jan (簡榮宏教授) B.S., NTHU-IE, 1979 M.S.,NTHU-IE,1983 Ph.D., NTHU-CS, 1987 Professor, NCTU-CS, 1987~ Chairman NCTU-CS, 1996 Visiting associate professor, UMD-CS 1992 Research projects in last three years M4 wireless mesh networks: design and implementation GPRS/WAN Two-tier Mobility System Location-aware WWW An adaptive Web System for Heterogeneous for IPv6 Networks Home Network Gateway wit WAP and SMS Thin AP with Light weight Access Point Areas of research interests Mobile computing Wireless internet Computer networks Computer algorithms Network reliability Publications International journal: 32 International conference: 28

Prof. Yu-Chee Tseng (曾煜棋教授) B.S., NTU-CSIE, 1985 M.S., NTHU-CSIE, 1987 Ph.D., Ohio State University-CIS, 1994 Professor, NCTU-CS, 2000~ Chief Executive Officer, ITRI-NCTU Joint Research Center, 2005~ Chairman, NCTU-CS, 2005~ “Distinguished Alumnus Award”, 2005, The Ohio State University Distinguished Research Award (two times) Distinguished EE Professor Award, The Chinese EE Institute, 2005 Areas of research interests Wireless Network  Communication Protocol Mobile Computing Network Security Wireless Sensor Network Wireless Mesh Network Wireless VoIP Distributed System Parallel Processing Publications International journal: 91 International conference: 99 Book Chapters: 12 Patents: 2 granted, 5 pending

Prof. Chien-Chao Tseng (曾建超教授) Research Interests: Wireless Internet Infrastructure and Protcols, Wireless Internet Applications Topics: Integration of Wirelsss Networks: - 3G, GPRS, Wireless LAN, Bluetooth, PAN - Mobile IP, NAT, VPN, MPLS - Mobile Router and Proxy, Ad Hoc Networks - Fast Handover (802.11i) Seamless Handover for Wireless Internet - Drivers, Network Layer, Transport Layer, Application Layer - SIP Mobility, 802.11x, Authentications (802.1x, 802.11i) Wireless Internet Applications: -Mobile e-learning Platform, ITS Platform, Location-aware Applications -August 1989 - August 1996 Associate Professor, Department of Computer Science and Information Engineering, National Chiao Tung University. -August 1996 – Now Professor, Department of Computer Science and Information Engineering, National Chiao Tung University.

Prof. Kuochen Wang (王國禎教授) B.S., NCTU-Control Eng., 1978 M.S., Univ. of Arizona-ECE, 1986 Ph.D., Univ. of Arizona-ECE, 1991 Senior Engineers, Directorate General of Telecommunications, 1980-1984 Professor, NCTU-CS, 1999 ~ Research projects NCTU-MediaTek Project: Low power, handover and QoS schemes in heterogeneous wireless networks NSC Project: Dynamic localization in wireless sensor networks Areas of research interests Wireless networks and mobile Computing Sensor networks, ad-hoc networks, and mesh networks Power-aware computing and communications Network reliability and security Publications Journal papers: 22 Conference papers: 47 Book Chapters: 1

Prof. Shie-Yuan Wang (王協源教授) Research Interests Wireless Network Mobile ad hoc network Wireless LAN and mesh networks WiMax and WLAN integrated networks Network Simulation and Emulation Internet Technology Network System Design and Implementation Publications Journal Papers : 13 Conference Papers : 15 Book Chapters : 1 Patents : 1 Ph.D. (Harvard University), 1999 Associate Professor (NCTU), 2003– present Assistant Professor (NCTU), 2000-2003 Founder and director of NCTU “Network and System Laboratory,” 2000 – Vice director of NCTU EE college and CS college’s Honors Undergraduate Program, 2005 – Author of NCTUns Network Simulator and Emulator (As of 11/24/2005, more than 4,500 people from 95 countries have registered and download this tool)

Prof. Chien Chen (陳 健 教授) Assistant Professor (NCTU), 2002~ Energy-efficient Flooding in MANETs Topology Control and Data Aggregation in Wireless Sensor Networks Wireless Mesh Routing and Channel Assignment Survivable Wireless Mesh Networks WiMAX QoS Management Architecture (Intel & III) Connection Management – Measurement based CAC QoS Guarantee – Upstream scheduler Service Provisioning – Packet classification Broadband & Optical Networks Network Processor (Intel) NAPT, and IP Classifier (III) Traffic Engineering in GMPLS Networks (NSC) Publications International journal: 2 International conference: 13 Assistant Professor (NCTU), 2002~ Director & Chief Architect (Terapower) 2001-2002 Chief Engineer (Coree Networks) 2000-2001 Member of Technical Staff (Lucent, Bell Labs) 1996-2000 Lecturer (Tunghai University) 1986-1988 B.S., NCTU-CE, 1982 M.S.,NCTU-CE,1984 Ph.D., Stevens-EE, 1996 Research Interests Ad Hoc/Sensor/Wireless Mesh Networks (NSC) Link Stability Model and Adaptive Routing Strategy in MANETs

Prof. Hsi-Lu Chao (趙禧綠教授) Ph.D., NTU-EE, 2004 Assistant Professor, NCTU-CS, 2004/8~ A member of the IEEE and ACM Listed in the Marquis Who's Who in the World, 2006 Research interests Protocol design for wireless networks Broadband Internet Quality of Service issues On-going research includes: MAC layer issues in WiFi, UWB and WiMax Power saving technologies in MANETs, WSNs, WMNs QoS issues of multimedia delivery Mobility issues in heterogeneous networks Publications International journal: 3 Local journal: 1 International conference: 3

Prof. Chih-Wei Yi (易志偉教授) He is an Assistant Professor with the Department of Computer Science, National Chiao Tung University He received his Ph.D. in Computer Science from the Illinois Institute of Technology, May 2005. His research interesting focuses on wireless ad hoc networks, especially about the power saving issue. He has 9 articles published or accepted by famous journals, including IEEE TCOM, IEEE/ACM ToN, IEEE TPDS, IEEE IT, ACM MONET, WCMC, etc., and 10 papers published in international conferences, including INFOCOM, WCNC, ICC, MobiHoc, etc.. Contact information: Email: yi@cs.nctu.edu.tw Tel: +886-3-5712121 ext 56686