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

2. 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

3. 研發成果

4. A Cross-Layer Control Scheme for VoIP application over 802
A Cross-Layer Control Scheme for VoIP application over e Wireless Local Area Networks
Cross layer VoIP over e WLAN
Policy based e Network
Motivation:
Centralized admission control scheme for e 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)

5. 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 MAC protocol doesn’t support multi-channel and multi-interface

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

7. A Distributed Time-Slotted Multi-Channel Protocol for IEEE 802
A Distributed Time-Slotted Multi-Channel Protocol for IEEE 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.

8. Integrating SIP and IEEE 802
Integrating SIP and IEEE e 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 e WLAN (Y=4)

9. 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

10. 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

11. 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

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

13. 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

14. 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

15. 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.

16. 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

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

18. A Power-Efficient MAC Protocol for VoIP Traffic
over IEEE e 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

19. 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.

20. 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

21. 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

22. 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:

23. 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

24. 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

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

26. 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

27. 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 e WLAN)”,
工研院/學研計畫: "Communication Protocols for Wireless Access Networks". ( ~ )
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( ~ ).
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”( ~ )
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, 至

28. 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, 至
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, 至
M4無線網狀網路具品質知覺之無縫交遞(1/3), NSC,
含行動隨意網的MPLS無線基礎網路, NSC,
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,

29. 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

30. 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

31. 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

32. 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

33. 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, x, Authentications (802.1x, i)
Wireless Internet Applications:
-Mobile e-learning Platform, ITS Platform, Location-aware Applications
-August 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.

34. 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,
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

35. 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),
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)

36. 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)
Chief Engineer (Coree Networks)
Member of Technical Staff (Lucent, Bell Labs)
Lecturer (Tunghai University)
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

37. 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

38. 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:
Tel: ext 56686