Standardizations and Researches for 5GHz in Korea VMC

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Standardizations and Researches for 5GHz in
Korea(VMC)

• September 2009
• Hanbyeog Cho

M5 Workshop (Chicago)
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Contents
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Standardization activities

• TTA PG310 (ITS Telematics)
• WG3102 Radio communication
• WG3104 V2V communication
• - Build up July 5, 2007
• WG3105 In-vehicle network interface
• Processing standards (TTA WG 3104)
• - User requirements for V2V Comm ( June 26,
  08)
• - Architecture (Sept. 2007 Dec. 2008)
• - Physical layer (March 2008 2009)
• - MAC layer (March 2008 2009)
• - Routing protocol (May 2008 2009)

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Research for 5GHz

• Project Development of the VMC Technology
• Vehicle Multi-hop Communication
  )
• Participants
• Main ETRI
• Partners ICU, HMC, Fumate, ITT
• Project Leader
• Dr. Hyun Seo Oh (ETRI)
• Period 2007.3. 2009.2 (The 2nd year of the
  1st stage
• Main goals
• Enhanced system development
• Standardization of the communication
  specifications

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V2V / V2I Communication

• Vehicle Services will be categorized into
• V2V based Vehicle Safety Service Intersection
  Collision Avoidance
• V2I bases Convergence Service ITS/ Telematics/
  USN Convergence Service
• VMC (Vehicle Multi-hop Communication)
• V2V Service Use Case Warning message delivery to
  neighbor vehicles with multi hop technologies
• V2I Service Use Case Probe data collection/
  Traffic information, etc
• Propose New Challenging Technologies
• Mid-amble based Channel estimation for long
  packet
• Hybrid MAC

V2V Service Use Case
V2I Service Use Case
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Proposed technology

• Channel estimation using Mid-amble in high
  mobility
• . Conventional Preamble or Pilot Sub-carriers
  based Initial Channel Estimation
• - Problem Performance degraded for long
  packet reception
• . New Mid-amble based Channel Estimation and
  Tracking
• - Benefits Good performance for long packet
  reception because it provides initial and
  continuous time and channel phase acquisition

Midamble
VMC Training Structure
Proposed Channel Estimation Method
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Performance analysis (1/3)

• Simulation Environment
• Simulation Tool MATLAB R2008a
• System Specification IEEE 802.11p WAVE D1, IEEE
  802.11(2007)
• Data Transmission rate 3, 6, 12 Mbps
  (mandatory)
• Packet length 200 bytes
• Insertion Period of Midamble 10(3,6Mbps) and
  4(12Mbps)
• Channel Model
• WAVE Channel Model (10 channel models for V2I
  V2V)
• Georgia Institute of Technology Proposed
• Using measured data in 5.9GHz band
• Highway, Urban, and Rural area

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Performance analysis (2/3)

• Performance analysis for present scheme (LTS of
  preamble)
• Channel Model 1 (Worst case)
• Scenario VTV - Expressway Oncoming without
  Wall, 300m - 400m Model
• Vehicle speed 140 Km/h
• Packet length 200 byte
• Eb/No 20dB

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Performance analysis (3/3)

• Channel Model 1
• Packet length 200byte

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Proposed technology

• Hybrid MAC with priority control
• Conventional CSMA
• - Problem Throughput degradation for the
  increased number of users
• New CSMA/CA-TDMA combined MAC
• - Benefits Better throughput by time slot
  scheduling, useful for VANET and V2I

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Performance analysis (1/4)

• MAC simulation
• PHY 802.11a OFDM, 6Mbps fixed
• MAC 802.11 DCF, CSMA/CA-TDMA combined MAC
• Number of slot 4 slots
• Application CBR Traffic (Unicast, Broadcast)
• Simulation tool Qualnet 4.0 version

10, 20. 30, 40 broadcast flows
5, 10, 15, 20 unicast flows
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Performance analysis (2/4)

• Unicast Scenario
• Unicast CBR Flows 520
• Performance parameter Throughput Delay

Throughput (bps)
Delay sec
Number of flows
Number of flows
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Performance analysis (3/4)

• Unicast Scenario
• Unicast CBR Flows 520
• Performance parameter No of Retransmission
  (RTS)

No. of retransmission
No. of retransmission
Number of flows
Node ID Information
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Performance analysis (4/4)

• Broadcast scenario
• Broadcast CBR Flows 10 40
• Performance parameter Throughput Delay

Throughput (bps)
Delay (sec)
Number of flows
Number of flows
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Present results

• If the packet length is bigger than 40 byte,
• Present scheme using LTS is hard to recover the
  data based on the channel estimation and
  compensation
• More stable data recovery in the high mobility
  environment,
• Proposal of channel estimation scheme using
  Midamble
• More frequently sending the training symbols like
  long-training symbols
• Contention based MAC
• Proposal of time slot based MAC
• Time slots for low contention and load balancing
• Higher throughput

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Future Works

• Making one board integration (ITS W Congress)
• Simulation including synchronization
• Optimal Parameter for higher performance
• Insertion period of Mid-amble
• Hybrid MAC development and verification
• TTA standardization
• - Architecture
• - PHY
• - MAC
• - Routing

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Conclusion

• Starting to consider better performance of 11p
• Physical layer
• MAC layer
• Trying to standardize the better system
  specification
• TTA
• IEEE 802.11
• Several trial version of system development
• - ETRI
• - CVIS
• - CICAS, etc

Cooperative Intersection Collision Avoidance
Systems (CICAS) Cooperative vehicle-Infrastructure
System (CVIS)
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Thank you for listening!!