Implementation of Protocol for Efficient Data Storage and Data Dissemination in VANET

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Implementation of Protocol for Efficient Data

Storage and Data Dissemination in VANET

Nisha K.Warambhe*1 and Dr. S.S. Dorle*2

1. Department of Electronics Engg. G.H.Raisoni College o Engg, Nagpur 2. Department of Electronics Engg. G.H.Raisoni College o Engg, Nagpur

Abstract— This paper deals with the protocol design for Efficient Data Dissemination and Data Storage in vehicular adhoc network (VANET). Here a large amount of data is distributed to a dense vehicular network from roadside unit as well as from on board unit using WAVE and VIPER protocol respectively. It is proposed that the system will consists of one control node as a roadside unit and two mobile nodes as an on-board unit. Data is disseminated between the mobile nodes via control node using push-based V2V/V2I dissemination technique, and then data which is disseminated through control node in all mobile nodes are stored into the memory of AVRATMEGA32. Stored data can be retrieved for analysis of accident cause or any emergency situation occurs. Analog to digital conversion is required during disseminating data between control node and mobile node. The parameters used for the verification of data dissemination and data storage are Temperature, Location of vehicle and accident cause which depends on the event occurred at the node. Also a hardware model is designed which uses AVR ATMEGA32 micro-controller and RF Trans-receiver module and WINAVR and Cygwin is used for programming.

Index Terms— Vehicular adhoc networks (VANET), Data dissemination concept, AVR ATMEGA 16 and Transreceiver module and VANET alert parameter.

I.INTRODUCTION

Vehicular Ad-Hoc Network is a technology that uses moving cars as nodes in a network to create a mobile network, comes under the class of mobile ad-hoc networks. In VANET, Vehicles are expected to communicate with each other (V2V) and with roadside infrastructure (V2I) in order to enhance road safety applications and comfort applications such as collision avoidance, emergency message dissemination, dynamic route scheduling, real-time traffic condition monitoring and any kind of information spreading (i.e. movies, gaming and advertisement. Hence, Vehicular adhoc network is becoming more interesting in order to provide convenience and efficiency to drivers on the road [1] [2].

Most of the VANET application is based on disseminating data from an information source (data center) to many vehicles (destination) on the road. Data dissemination in VANETs not only helps drivers or vehicles to inform for traffic jams but also to propagate emergency warning among the vehicles to avoid collisions. Vehicles on road face problems of heavy traffic flow and instability and results in road accidents. By forwarding appropriate information to the driver or vehicle on the road like Congestion and traffic management, lots of lives, money, and time can be saved. Numbers of innovations have been done to increase safety, comfort, and convenience. Hence, data exchanging or data disseminating on the roads is becoming more and more interesting due to increase in the number of vehicles equipped with computing technologies and wireless communication devices. So data dissemination in VANETs plays an important role for safety and non-safety application.

Recently, efforts have been started to address data dissemination issues in the VANET. In this approach, a data pouring (DP) and buffering approach to solve the data dissemination problem in a VANET is. In DP, data are periodically broadcast to vehicles on the road. In DP with intersection buffering (DP-IB), first data is poured from the source and then buffered. After that, rebroadcasting at the intersections is carried out [3]. Also, a mobility-centric approach for data dissemination in vehicular networks has been designed to enhance reliability of the highly mobile, partitioned nature of these networks [4]. In VANET, data dissemination assumes either that mobile nodes move randomly or any two nodes can be expected to be close to each other from time to time because they have limited area [5].

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diverse type of applications like traffic management, situational awareness, and commercial services The aim of data dissemination is to maximum utilize network resources to fulfill the demand of all users participating in vehicular network. In this paper, the main goal is to solve the data dissemination problem for I2V2V communication scheme and to increase efficiency, convenience, privacy and safety of drivers and RSU present on the road. The designed protocol can reliably disseminate the data and maximize the dissemination capacity. It uses a push based data dissemination approach where data is efficiently pushed to the user present in transmission range. It helps to avoid collision of vehicles, monitoring traffic analysis.

Paper is divided into two sections; Section II narrates review and concept for data dissemination and data storage approach and section III, IV and V narrates design for hardware module and simulated results.

II.OVERVIEW

A. Need of Data Dissemination and Data Storage in VANET

Vehicular ad hoc networks face a number of challenges with the services they provide. The most common challenges are in the aspects of security and privacy [7]. With regard to security, VANETs can be exploited to send out improper information to other vehicles [8]. This may be done for the purpose of either clearing up one's own way or throwing another vehicle out of its way by means of false traffic reports. On the aspect of privacy, VANETs allow access to information on speed, status and locations of the vehicles within its range [9] [10]. This kind of information may be exploited by observers to draw conclusions about a driver's personality, lifestyle and social relationships. To enhance the security and privacy of vehicular network, Data dissemination and data storage in VANETs must be accurate. It is extremely important to consider several aspects while considering any kind of data transfer or data dissemination in a VANET. Thus the correct approach for data dissemination in VANETs is necessary to adapt the dissemination mechanism according to the different network environments. These aspects include high mobility and partitioned network [3].

1. High mobility:

The environment in which vehicular networks operate is extremely dynamic, and includes extreme configurations: in highways, relative speed of up to 300 km/h may occur, while density of nodes may be 1-2 vehicles per kilometer in low busy roads. Because of the relative movement of the

vehicles, the connectivity among nodes could last only few seconds, and fail in unpredictable ways.

2. Partitioned networks:

Vehicular ad hoc networks will be frequently partitioned. The dynamic nature of traffic may result in large inter-vehicle gaps in sparsely populated scenarios, and in several isolated clusters of nodes. The degree to which the network is connected is highly dependant on two factors, such as the range of wireless links and the fraction of participant vehicles, since only a fraction of vehicles on the road could equipped with wireless interfaces. Maintaining end-to-end connectivity, packet routing, and reliable multi-hop information dissemination will become extremely challenging in such networks. As it concerns specifically the data transmission in VANETs there are several additional issues to take into account:

 The signal fading, which becomes really fast due to the surrounding buildings;

 The strong interference and collision related to the high number of mobile transmitters (vehicles);

 The flapping links caused by fading effect and vehicles speed.

These aspects make vehicular networks different and significantly affect their design. The data dissemination destination idea has to compete with the limitations of time, space and vehicles. There is a need to introduce push strategies, where vehicles push data to their neighboring vehicles so that other vehicles can easily access data when necessary. These strategies in turn need to consider the impact to data caching and aggregation.

B. Data Dissemination in VANET

The data dissemination is the process of spreading some amount of data over a distributed wireless network. It is used to improve the quality of driving in terms of time, distance, and safety. The data dissemination techniques are classified as follows:

1. V2I /I2V dissemination

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each vehicle present in transmission range [3] [6]. E.g.: Traffic condition, e-advertisement etc.

b. Pull based: In Pull based data dissemination; any vehicle is enabled to request information about specific location or target. This is also called as request and response model. It is used for user-specific type of data [3] [6]. E.g.: Enquiry about parking lot, coffee shop etc.

2. V2V Dissemination

a. Flooding: In flooding, every node participates in dissemination process and the data is created and received in vicinity. It can reliably & quickly distribute data. This approach is used for delay sensitive application and also for sparse networks during low traffic conditions. But it is not suitable for dense network.

b. Relaying: In relaying type of data dissemination, first the relay node is selected (next hop).Then relay node forwards the data to the next hop and so on. The main advantage of this approach is it reduces congestion and hence, it is used for congested networks or dense network. Comparison of data dissemination approaches is shown in table1:

TABLE 1

COMPARISON OF DATA DISSEMINATION APPROACHES

Dissemination Approach

Pros Cons

Push based Suitable for popular data

Not suitable for unpopular data Pull based Suitable for

nonpopular data, user specific data

Cross traffic incurs heavy interferences, Collisions. Flooding Reliably and

quickly distribute data

Not suitable for Dense networks.

Relaying Works well in dense networks

Selecting best next hop & reliability is difficult

Out of four disseminating approaches, Push based dissemination approach has been used for protocol design as it is more suitable for transmitting data between the nodes.

III.PRAPOSEDDESIGN

A.Basic idea

In VANET, basically two nodes are required for the V2V and I2V communication, called as VANET nodes. These nodes are on board unit (OBU) or mobile nodes and

roadside unit (RSU) or control node [4]. On board unit is installed in each vehicular node and controlled by network operator while roadside unit or infrastructure is available at

road and constitutes network

infrastructure.AVRATmega32 micro-controller is used for VANET nodes. For wireless communication between the both modules, Transreceiver is needed which is interfaced with the AVRATMEGA32. Following points explains the proposed plan of work.

1. A Trans-receiver module is connected to every mobile node (Vehicle).

2. A Trans-receiver module is connected to a control node (Infrastructure).

3. Once the vehicle is in range, it would start disseminating data to the vehicles within the vicinity.

4. If two vehicles are close to each other then one of them would slow down the speed, and inform the other vehicle to slow down as well.

5. The vehicles when in range of the control node would upload/download all the location based data as well as weather information of communicating area.

6. This process would be repeated within the system.

FIG 1:BLOCK DIAGRAM OF PROPOSED PLAN

Fig 1: shows that the data thus obtained from neighboring nodes will be transmitted to all the mobile nodes (vehicles) via control node which constitutes the V2V communication as well as V2I communication in the network. Depending upon the data, required action will be taken by driver. Main function of system is to store data which is obtained from nodes. Three disseminating parameter is used as Vehicle Location with node number, Accident Cause and Temperature Measure for verifying data dissemination

Control N od e (RSU)

Mobile

N od e 2

(Vehicle) V2V V2I

Data Storage

Mobile N od e 1 (Vehicle)

Data w ill be

d isp layed On

LCD of AVR kit.

Data w ill be d isp layed On LCD of AVR kit

LCD display of each node w ill display follow ing data

1. Vehicle Location w ith node number 2. Accident Cause

3. Temperature Measure

Data

Dissem ination

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approach. Information about all three parameters will be displayed on LCD display of both control node and mobile node. For verification of data storage approach, data present at each node is uploaded to computer via serial port (COM19) and results are verified in MATLAB software.

B. Hardware Implementation

ATMEGA32 comes under the family of AVR .The acronym AVR has been reported to stand for advanced Virtual RISC processor and was developed by Atmel in 1996. AVR is a modified Harvard architecture 8-bit RISC single chip micro-controller. It uses on-chip flash memory for program storage. Atmega32 is a 40 pin DIP package IC and has 32-KB of On-chip flash memory. It executes powerful instructions in a single clock cycle which increases the ATmega32 throughputs approaching 1 MIPS per MHz and allows the system designer to optimize power consumption versus processing speed.ATmega32 has four ports as Port A, B, C and D. Here, Port A acts as A-D converter. Pin no 1, 2, 3 and 4 of port B are used for input data and pin no 14 and 15 of port D are used for transmitting and receiving data between the nodes.ATmega32 AVR is supported with a full suite of program and system development tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit emulators, and evaluation kits.

For wireless data transfers between nodes, RF Transreceiver module is used. RF Transreceiver module consists of PCF10 (FS1000A) 433 MHZ as a RF transmitter and PCR2A as a RF receiver. Costs of RF modules are very low and are compact in size. These are good for short distance and battery power device development. Operating frequency range is around

433MHz. Amplitude Shift Keying (ASK)

or Frequency Shift Keying (FSK) is mainly used for wireless data transfers. Here, ASK is used for transmission. Both the receiver and transmitter are quite easy to interface. Supply voltage range is 3-12V. These low cost RF transmitter and RF receiver can be used to transmit signal up to 100 meters (the antenna design, working environment and supply voltage will seriously impact the effective distance). It has only single channel. The serial data given at the input TXD of the transmitter will be received at the RXD of the receiver. The maximum data rate is around 4KBps. RXD and TXD are TTL compatible. HT series of encoder/decoder pair IC's are used in RF receiver module for parallel to serial and the reverse conversion of data. Both the receiver and transmitter are three terminal devices with pin outs as shown below.

Receiver Module

Antenna

VCC

Transmitter Module

Antenna

GND

FIG 2:PIN OUTS OF RECEIVER AND TRANSMITTER

Finally for Temperature measure of surrounding, LM 35 is used. It is small in size and gives 10mv/°c value output for every sensation. Its value is always in analog .Hence, it is required to be convert in to digital so after digital conversion its input is given to the pin no 40 (ADC0) of IC ATMEGA32. As ATMEGA32 has internal 10 bit ADC, external ADC is not required. Temperature sensor is used only at control node. For sending data of temperature measure to all nodes, ADC library of WinAVR has to be used while programming. Small change in temperature measure is transmitted to each vehicle present in communication range of 100m. Each node can store 100 readings of temperature measure.

Complete hardware is going to work on AC/DC adapter of +12V. Most of IC are run on the + 5v supply. Hence, L7805 IC is used to convert required desired value for operation. Four push keys of AVR microcontroller kit are used for verifying results.

FIG 3: ACTUAL HARDWARE IMPLEMENTATION OF CONTROL NODE AND MOBILE NODE

PCR2A

RXD GN D

FS1000A

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Figure 3: shows the hardware implementation for designed protocol where AVR ATMEGA 32 kit is interfaced with the RF transmitter and RF receiver.

IVDESIGNAPPROACHFORDATADISSEMINATION

ANDDATASTORAGEINVANET

The main purpose of all VANET applications is to enhance the vehicular communication between vehicles as well as infrastructure. In designing approach, WAVE (Wireless Access for Vehicular Environment) protocol is used for data transfer in V2V communication [11] while VIPER (vehicle-to-infrastructure communication privacy enforcement) protocol is used for data transfer in V2I communication [13]. In this section, various aspects have been used for designing purpose. First, the coding technique is presented, which play a key role in the dissemination problem. Next, the set of rules that govern data transfer is described.

A. VANET Alert parameters

The conventional approach to reduce collisions and the hidden node problem in network is using the VANET alert parameters. Two Alert parameters have been declared for data transfer as Vehicle location and Vehicle accident. These parameters are defined for each mobile node in the network. Also temperature measure is defined for weather information of communication area, which helps to understand the design approach for data dissemination and data storage in VANET. All the three parameters stores 100 readings in the memory of Atmega 32. One more important thing is consider when there is a change in temperature, it shows that change at mobile nodes first and then at control node, which in turn reduces time constraints.

B. Processing Steps for Data Transfer

For data transfer between the control node and mobile nodes, three parameters (Temperature measure, Vehicle location and Vehicle accident) are decided as a VANET alert parameter. For these parameters, four events are defined as three events for check point and one event for accident. Whenever an event is occurred at any node, control node check out the type of event and number of type. After verification of event, the data of the respective event is transmitted to different nodes. If the mobile node is damaged due to any circumstances, data is stored in the respective node always. Processing steps for data transfer is given below:

TABLE 2: PROCESSING STEPS FOR DATA TRANSFER

Processing Steps Parameters to be select by vehicle

Start of transmission

Node Number Node 1 or Node 2

Event Type Check point Event or Accident Event

Event Number Check point 1 or Check point 2 or Check point 3 or Accident

End of transmission

After End of transmission, the data is then sent to respective node.

V.SIMULATIONRESULT

According to VANET alert parameter, Simulation results are taken. WINAVR tool is used for programming purpose while compilation of programs is done using Cygwin tool.

FIG 4:TEMPERATURE DISSEMINATION

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FIG 5:LOCATION DETECTION

Fig 5: shows the result for location detection where check point event has been detected at location 1 and then it is disseminated and data is stored at node2.

FIG 6:ACCIDENT DETECTION

Fig6: shows the result for accident detection where accident event has been detected at location 1 and then it is disseminated and data is stored at both nodes 1 and 2.

VI.CONCLUSION

This paper deals with the design of a protocol for efficient Data storage and data dissemination in vehicular adhoc network. WINAVR and Cygwin are chosen as the implementation tool because of the close integration with AVR micro-controller family, which also allows close coupling of the MATLAB model with the equivalent hardware implementation. After the testing of the VANET alert parameters, it is observed that using AVR microcontroller data is easily stored and disseminated at node. As the AVR atmega 32 has 32 bit on chip flash memory, external memory is not required which in turn reduces the cost.

VII.FUTUREWORK

Results obtained for temperature dissemination, location detection and accident detection can be further verified using MATLAB tool. Graphs for each result will help to understand the concept of data storage and data dissemination approaches of VANET.

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