IEEE 802.11 WLAN: Trends and My Research

1
IEEE 802.11 WLAN Trends and My Research

• October 14th, 2006
• Sunghyun Choi, Ph.D.
• Associate Professor
• Multimedia Wireless Networking Laboratory
  (MWNL)
• School of Electrical Engineering and Computer
  Science
• Seoul National University
• http//mwnl.snu.ac.kr
• schoi_at_snu.ac.kr

2
Introduction to Myself

• BS, MS from KAIST in 92, 94
• Ph.D. from UM in 1999
• Prof. Shins No. 40 Ph.D.
• First Ph.D. in Wireless QoS Guarantees in
  Wireless/Mobile Networks
• Philips Research in New York from 1999 to 2002
• Started working on 802.11 (standardization,
  development, etc.)
• Seoul National University (SNU) since 2002

3
School of EE in SNU

• Numbers
• Faculty 63
• Ph.D. students 250
• M.S. students 300
• B.S. students 1,200
• Prof. Shin got B.S. from EE/SNU!
• SNU 60th year anniversary (10/15)
• Prof. Shins 60th birthday (10/20)

4
Introduction to My Group

• Members
• 1 post-doc
• 6 Ph.D. students
• 6 M.S. students
• Past/Current Sponsors
• Brain Korea 21
• Ministry of Science and Technology (MoST)
• Ministry of Information and Communication (MIC)
• Ministry of Commerce, Industry, and Energy
  (MoCIE)
• Electronics and Telecommunications Research
  Institute (ETRI)
• Samsung Electronics, Korea Telecom (KT), Intel,
  HP

5
My Research Areas

• MAC and around
• Cross-layer aspects
• Working with many PHY folks
• New protocols and/or evolution
• Implementation-dependent algorithms
• Standardization
• Target systems
• WLAN, 4G, WMAN/Mobile WiMAX, mesh, (WPAN, sensor
  networks)

6
WLAN vs. Other Solutions
WAN
Mobility
WLAN
High performance WLAN
UMTS Wideband Cellular
GSM IS-95
Wired LAN
802.11n
802.11a/g
802.11b
Bluetooth
Mbps (Tx Rate)
1
10
100
0.1
7
802.11 Standards as of 2005
8
On-going Standardization
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Current Trends in WLAN

• Higher speed
• 11b ? 11a/g ? 11n
• Fast mobility support
• Related to VoIP
• 11r, 11k
• More power saving
• 11e, 11n power saving for active flows
• 11v deep power saving
• Mesh networking
• Proprietary solutions ? 11s
• WLAN switch
• Proprietary solutions

10
My Current Work on WLAN

• Scheduling and admission control
• Link adaptation
• Power saving
• Handoff
• Vertical handoff

11
Collision-Aware Rate Adaptation (CARA)
Ref INFOCOM 2006
12
Idle Mode Operation

• Proposed for 11v

Ref ICC 2006, WMASH 2006
13
Idle Mode Performance
Estimated standby time of a VoIP device
14
Long-Term TCP over WLAN
15
Hidden Station Detection
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Concluding Remarks

• WLAN is evolving today
• Still reasonably many open research issues
• I am enjoying working in this exciting area ...