a dedicated multi-channel mac protocol design for vanet with adaptive broadcasting ning lu 1,...
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A Dedicated Multi-channel MAC Protocol Design for VANET with
Adaptive Broadcasting
Ning Lu1, Yusheng Ji2, Fuqiang Liu1, and Xinhong Wang1
1Dept. of Electronics and Information Engineering, Tongji University, Shanghai, China
2National Institute of Informatics, Tokyo, Japan
IEEE WCNC 2010
Outline
Introduction The DMMAC protocol Performance evaluation Conclusion
Introduction
Many advanced wireless technologies are being applied to transport systems Safe Intelligent Efficient
In particular, the Vehicular ad hoc network (VANET) Vehicle to Vehicle (V2V) communication Vehicle to infrastructure (V2I) communication
Introduction
The MAC protocol for VANET is critical to provide efficient and reliable medium access, but Fast topology change High node mobility Different Quality of Service(QoS) requirements
Introduction_goals
Authors propose a dedicated multi-channel MAC protocol, called DMMAC, for VANET Adaptability broadcasting provides collision-free and
delay-bounded transmissions for safety messages Higher communication throughput Lower network latency
The DMMAC protocol_Background
IEEE 1609.4 provide an important multi-channel MAC CCH(control channel) interval
Safety messages and control packets
SCH(service channel) interval Exchange data
The DMMAC protocol
Frame architecture of DMMAC
BCH(Basic Channel)
The DMMAC protocol
CCH Interval SCH Interval
Sync Interval
ABF CRP
ABFL (ABF Length)
ABFLmin , ABFLmax
TDMA CSMA/CABCH Basic Channel
The DMMAC protocol
ABF CRP
CCH Interval
The DMMAC protocol
1. BCH Reservation process
2. Computation of ABFL
3. Virtual Slot operation
The DMMAC protocol
BCH Reservation process
ABF CRP
CCH Interval
Each slot can only reused by one neighbor
The DMMAC protocol
BCH Reservation process FI (Frame Information)
Free or Busy
The slot occupation within One-hop and 2-hop
Rule 1: if a packet has been successfully received or transmitting
Rule 2 : to reserve a BCH not used within two hop
The DMMAC protocol
BCH Reservation process
The DMMAC protocol
BCH Reservation process
Rule 3: to reserve empty slot
Busy Status(BS)
TransmittingVehicle Identifier(ID)
Slot information
The DMMAC protocol
Computation of ABFL
ABF CRP
CCH Interval
ABFLi = max[ALk]+SFLAL (Active slot)
The DMMAC protocol
Computation of ABFL Rule 4 : ABFLi=ABFL max
The DMMAC protocol
Virtual Slot operation
ABF CRP
CCH Interval
Contend to CRP-REQ or CRP-BRD
The DMMAC protocol
Virtual Slot operationRule 5 : if vehicle i want to send CRP.Wait for the ended of ABFs of one-hop
Mute slot
The DMMAC protocol
Virtual Slot operation
Rule 6
The DMMAC protocol
Virtual Slot operation Rule 7 : vehicle i can send the CRP-REQ to vehicle j(one-hop)
Performance evaluation
Simulator ： NS-2 Parameters
Performance evaluation
Sparse scenario
Performance evaluation
Dense scenario
Performance evaluation
Results of BCH reservation in sparse scenario
Performance evaluation
Results of BCH reservation in dense scenario
Performance evaluation
Delivery ratio of safety packets
Conclusion
This paper presented a dedicated multi-channel MAC(DMMAC) protocol for VANET collision-free and delay-bounded transmission for
safety applications