Wireless traffic service platform for
combined vehicle-to-vehicle and
vehicle-to-infrastructure communications
Authors : T. Sukuvaara and P. Nurmi
Speaker : 蔡明信
IEEE Wireless Communications, Vol 16, pp. 54 - 61 , December 2009
outline
 Introduction
 Related work
 Platform and services
 System description
 Technical requirements
 Available wireless technologies
 Performance analysis and discussion
 Conclusions
Introduction
 The vehicle-to-vehicle (V2V) communication platform
is currently a popular research topic
 Traffic safety enhancement is the driving factor in many
approaches,sensor data from vehicles and roadside units
is used for providing accident and/or weather warnings
to roadside units and vehicles.
Introduction
 The capability for continuous communication is an important
goal.
 In the carlink project the aim was to build more
comprehensive solution for vehicle-to-infrastructure (V2I)
and V2V communication purposes.
 Employed hybrid communication of general packet radio
service (GPRS) and wireless networking.
Introduction
 Wireless networking stands for the ultimate
communication platform, while GPRS’s primary
purpose is to provide an alternate communication
solution.
 The simulations, pilot testing, and analysis evaluate the
basic communication efficiency of the platform.
Related work
 In the United States the Department of Transportation is
coordinating the Vehicle Infrastructure Integration (VII)
program.
 The European (Cooperative Vehicle Infrastructure
Systems)CVIS project generates an open standardsbased communication.
Related work
 The main advantages of carlink are the open platform
solution, the flexibility and scalability of the platform
into different types of services and capacity
communication requirements, and operation reliability
based on dual radio communications.
Platform and services
 The Carlink platform is designed to provide an
infrastructure to a wide community of commercial and
governmental traffic and safety services.
Platform and services
The wireless traffic service platform is divided into three
parts:
1. Traffic service central unit (TSCU)
2. Traffic service base stations (TSBSs)
3. Mobile end users (MEUs)
Carlink services.
Operational model of local RWS and
incident warning service.
Schematic of the road weather model.
System description
 The TSCU is on the top with connections to the
underlying service cores , it also stores all data gathered
from the platform and forwards the appropriate data to
services.
 Road weather service(RWS) core includes a weather
forecast model
 The parameters gathered from the vehicle are the
temperature, car throwing indicator, car sudden braking
indicator, airbag blast notification
 The WLAN/WiMAX and GPRS interfaces are used for
communication with the TSBSs and TSCU.
Carlink platform structure
Technical requirements
 The traffic speed (up to 100 km/h in our scenario)
generates an extremely challenging element
 Ad-hoc networking with handoff and seamless
continuation of communication are important issues
required in the final operative system.
Technical requirements
 The most popular solution for wireless communication
is the Wi-Fi system, which is based on the IEEE 802.11
standard family.
 IEEE 802.11p represents the ultimate future solution
Technical requirements
 wireless ad hoc communication between vehicles
 ensure that the most crucial data will also be exchanged
in the platform without any delay when there are no
TSBSs nearby.
Available wireless technologies
WLAN :
 Wi-Fi
 WiMAX
PERFORMANCE ANALYSIS AND
DISCUSSION
Two main simulation :
1. One-way traffic scenario
2. Bidirectional traffic scenario
PERFORMANCE ANALYSIS AND
DISCUSSION
Conditions :
 four or eight vehicles are traveling at 100 km/h speed
 The distances between consecutive vehicles were fixed
to 100 m
Main results of the simulations
Conclusions
 Presented the carlink concept of a hybrid wireless traffic
service platform between cars
 Showcases a true bidirectional communication entity
 Analyzed and forecast information about road weather
conditions and immediate incident warnings.
Conclusions
 Decrease accidents and lives lost in traffic.
 The ultimate goal was to create an intelligent
communication platform.