Simulator integration:Vissim (Environment simulator) +

NS2 (Telecom simulator) =

RuBeNS Rural & UrBan e-Travelling Network Simulator

Péter Laborczi

Sándor Kardos

Attila Török

Lóránt Vajda

Main goal

Integrate environment simulator with telecommunications simulator to evaluate protocols for specific scenarios

1. Pile-up avoidance scenario (accident prevention)

2. Road traffic information scenario (traffic jam avoidance)

3. Ad hoc tempomat scenario (driving comfort)

Example

Floating Car Data:

• Vehicle act as moving sensors

- GPS

- Weather sensors

- Radar

Distributed

Centralized

Emergency signalling implementation

Purpose:

• Test the effects of wireless emergency warning signalling

Why?

• If legal restrictions forbid intervention (breaking), only signalling is possible

Implemented signalling

• Vehicle detecting accidents broadcasts warning message

• Messages are forwarded up to 1000m by cars

• Equipped car drivers are notified when the message is received

• Cars with no warning device notice the problem 1.5 seconds after the supposed reception

Ad hoc traffic information sending/handling

Purpose:

• To avoid traffic jams without centralinfrastructure

Why?

• Reduce travel times withouta single point of failure and maintainance costs

Implemented signalling

• Equipped cars send travel time information

• They receive information for all neighboringstreets

• Based on this information they reroute whennecessary

GPS module

Purpose:

• Realistic modelling of GPS errors

Why?

• Crucial to prevent bump-ins

Error sources and modelled error [m]:

Error source GPS DGPS

Satellite Clocks 1.5 0

Orbit errors 2.5 0

Ionosphere 5 0.4

Troposhere 0.5 0.2

Receiver noise 0.3 0.3

Multipath 0.6 0.6

Graph representation of road network

Purpose:

• To have a mathematically tractablemodel of the map

Why?

• To be able to find shortest path (Dijkstra)between locations and be able to selectrelevant messages

Implementation of an online ”converter”from Vissim road network format to our(Boost library based) graph format

Realworld map converter

Purpose:

• Convert XML format mapfile to VISSIM format

Why?

• To be able to simulatetraffic in real cities

Part of Budapest (BUTE surroundings) can nowbe examined within RuBeNS

Danube

Kalvin sqare

BUTE surroundings

XML based traffic matrix handling

Purpose:

• To have an easily usable trafficdescription

Why?

• To be able to examine differenttraffic conditions

Implementation is based on xmlwrapp library

Vehicular communication systems - Software Modules

VISSIMRoad traffic simulator

VISSIM interface

TCP/IP Socket

NS-2

TCP/IP Socket

PHY

CommunicationProtocol

Application / Group comm.

interface

interface

WindowsLinux

Four Scenarios

1. Traditional see the DEMO

• No equipped vehicles

2. Centralized FCD

3. Distributed FCD see the DEMO

• Ad-hoc route guidance

4. Cooperative route guidance see the DEMO

Average Travel Time

Traditional scenario Centralized FCD Distributed FCDCooperative Route

Guidance

Average travel time 386.5 sec 164.2 sec 156.8 sec 114.2 sec

Route travel times

Lookout

Simulation environment RUBeNS implemented to simulate:

• Road network & vehicle traffic

• Infocommunication network & data traffic

Different FCD approaches and communications simulated

More applications are under development:

• Ad-hoc tempomat (ACC)

• pile-up avoidance

• Intelligent flooding protocol

Study of the communication network:

• Load

• Latency

• Reliability