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RFID based design for vehicle location system


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RFID based design for vehicle location system is MSc thesis in computer engineering. It by Hassan Abdulsalam Hamid

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RFID based design for vehicle location system

  1. 1. RFID BASED DESIGN FOR VEHICLE LOCATION SYSTEM A Thesis Submitted to the College of Engineering of Al-Nahrain University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Computer Engineering by HASSAN ABDULSALAM HAMID (B.Sc., 2006)Thoul Hijjah 1432November 2011
  2. 2. Abstracts Due to the rapid growth in the number of vehicles on the street, trafficproblems are bound to exist. Hence, implementation of IntelligentTransportation Systems (ITS) to obtain traffic information from roads byAutomatic Vehicle Identification (AVI) is becoming an urgent necessity. TheRadio Frequency Identification (RFID) Technology can be used for AVI tocollect the traffic information in real-time from roads by getting the vehiclesID from RFID readers. This thesis tackles the problem of designing Vehicle Location System(VLS), the proposed system consists of a passive RFID tags on vehicles,RFID reader, readers antenna, wireless communication with a CentralComputer System (CCS) and commanding software (RFID middleware anddatabase structure), also VLS applications, SMS server and website. Thedesigned system controls, manages and monitors the performance of RFIDreaders. It also filters and stores the information in a suitable form to be easilyused in the application system and website. The system implemented by usingRifidi Platform as simulator for RFID system and VLS is programmed byVisual Basic 2010. The VLS is composed of installing of two RFID readers intraffic intersections; each reader has four antennas, for monitoring all entriesand exits of the intersection. The VLS used the gathered data from traffic intersections RFID readersin many applications including the following: location of vehicles inintersections at any time, path and orientation of vehicle in intersections,numbers and vehicles ID passed in each intersection at any time, estimate thetraffic congestion situation in roads and intersections through SMS server andwebsites, drawing path of vehicles within VLS region on map, monitoringillegal and stolen vehicles real-time and tracking certain vehicle color. I
  3. 3. List of Contents Contents PageAbstract IList of Contents IIList of Abbreviations IVList of Tables VIList of Figures VIIChapter One: Introduction1.1 Overview 11.2 Literature Survey 21.3 Aim of the Work 61.4 Thesis Outline 7Chapter Two: RFID Technology and Applications2.1 Introduction 82.2 RFID System Components 82.3 RFID Tags 9 2.3.1 Tag Types 11 2.3.2 Tag operation 12 2.3.3 Electronic Product Code (EPC) Tag 12 2.3.4 Tag Memory 142.4 RFID Reader 15 2.4.1 Energize the Tag 17 2.4.2 Frequency ranges 18 2.4.3 Communicate with the Host Computer 192.5 RFID Antenna 192.6 RFID Middleware 222.7 Automatic Vehicles Identification (AVI) based on RFID 25 2.7.1 RFID Hardware’s Properties Requirements 25 2.7.2 Applications of System 26Chapter Three: The Proposed Vehicle Location System3.1 Introduction 293.2 System Architecture 293.3 System Structure 32 II
  4. 4. 3.3.1 The VLS Middleware 33 3.3.2 Database 37 Traffic Intersections Table 37 Vehicles Table 38 Data Online Table 38 Vehicle Location Table 39 Black List Vehicles Table 39 Authorized Users Table 393.4 Rifidi Platform 393.5 Roads and Traffic Intersections Simulation (RTIS) 41 3.5.1. The RTIS Architecture 41 3.5.2. The RTIS Scenario 423.6 RFID Readers Connection Protocols 453.7 The Methods of VLS Applications 46 3.7.1 Tracking Method for Vehicle Movement 46 3.7.2 Estimation of Traffic Congestion 493.8 VLS Client Access 51Chapter Four: Implementation of Vehicle Location System4.1 Introduction 544.2 Vehicle Location System 544.3 The Main Program of VLS 56 4.3.1 The VLS Security 56 4.3.2 The VLS Tables 57 4.3.3 Setting Database and Authorization 63 4.3.4 The Connection with RFID Readers 66 4.3.5 The Traffic Congestion Appraisal 68 4.3.6 The Vehicles Locations Discovery 71 4.3.7 The Vehicle Path Map 71 4.3.8 The Intersection Monitoring and Tracking Vehicle 72 Color4.4 Traffic Congestion Status Website in VLS 744.5 Street Traffic Congestion Appraisal / SMS Server 764.6 General Discussion 78Chapter Five: Conclusions and Suggestions for Future Work5.1 Conclusions 805.2 Suggestions for Future Work 81References 83 III
  5. 5. List of AbbreviationsAT AttentionAT commands Set of commands used to control the modemAVI Automatic Vehicles IdentificationAIDC Automatic Identification Data CollectionAPI Application Programming InterfaceASP.Net Active Server Pages.NetCCS Center Computer SystemDHCP Dynamic Host Configuration ProtocolDSRC Dedicated-Short Range CommunicationsEAS Electronic Article SurveillanceEIRP Effective Isotropic Radiated PowerEPC Electronic Product CodeETC Electronic Toll CollectionGIS Geographic Information SystemGPRS General Packet Radio ServiceGPS Global Positioning SystemGSM Global System for Mobile CommunicationsGUI Graphical User InterfaceIFF Identity: Friend or FoeIIS Internet Information ServerIOT Internet of ThingsISO International Standards OrganizationITMS Intelligent Traffic Management SystemITS Intelligent Transport SystemPDU Protocol Description UnitRFID Radio Frequency IdentificationRO Read-OnlyRTIS Roads and Traffic Intersections SimulationRW Read-WriteSIM Subscriber Identity ModuleSMS Short Message Service IV
  6. 6. SNMP Simple Network Management ProtocolSQL Structured Query LanguageSTCA Street Traffic Congestion AppraisalTCP Transmission Control ProtocolTCP/IP Transmission Control Protocol/Internet ProtocolTICS Traffic Information Collection SystemTMS Traffic Management SystemUHF Ultra High FrequencyV2I Vehicle-to-InfrastructureV2V Vehicle-to-VehicleVLS Vehicle Location SystemVRT Virtual Route TrackingWi-Fi Wireless FidelityWORM Write Once-Read Many V
  7. 7. List of TablesTable Title Page 2-1 EPC RFID classes 13 2-2 EPC RFID chip generations 14 2-3 RFID frequency bands 18 VI
  8. 8. List of FiguresFigure Title Page(2-1) Components of an RFID system 9(2-2) Typical design of passive tag 9(2-3) Passive UHF RFID tag block diagram 10(2-4) EPC tag content 14(2-5) Typical electrical connections for RFID reader 16(2-6) Typical passive RFID tags with different antennas 20(2-7) Estimation of velocity 28(3-1) Architecture of traffic intersection in VLS 30(3-2) Simulation of traffic intersection 31(3-3) The communication method for VLS system 32(3-4) The flowchart of the middleware performance 36(3-5) The vehicles and roads network in RTIS 43(3-6) The gathered data 44(3-7) The significance of the gathered data 44(3-8) The connection between client and server on 45 specific port (3-9) Principle of VRT algorithms 46(3-10) The flowchart for drawing the VRT on the map 48(3-11) The flowchart for traffic congestion estimation 51(3-12) GSM modem communications 52 (4-1) The layout of the VLS environment 55 (4-2) The implemented VLS 55 (4-3) Main form of VLS 56 (4-4) The security form 56 (4-5) Traffic intersection table 57 (4-6) Vehicles table 58 (4-7) Data online table 59 (4-8) Vehicle location table 59 (4-9) Black list vehicles table 60(4-10) The vehicle which in black list is detected 60(4-11) Deleting vehicle ID from black list table 61(4-12) Tables update form 61(4-13) Update of traffic intersections table 62(4-14) Update of vehicles table 63 VII
  9. 9. (4-15) Setting database and authorization 63(4-16) A message of cleaning tables successfully 64(4-17) Restore database 65(4-18) Password change form 65(4-19) The connection form with RFID readers 66(4-20) The connection shutdown irregularly 67(4-21) RFID readers table 67(4-22) The connection stream 68(4-23) The traffic intersections congestion appraisal 69(4-24) The street traffic congestion appraisal 70(4-25) The vehicles locations discovery 71(4-26) The vehicle path map 72(4-27) The Intersection Monitoring 73(4-28) Tracking vehicle color 73(4-29) The website of intersection congestion estimation 75(4-30) The website of street congestion estimation 75(4-31) Street Traffic Congestion Appraisal / SMS Server 76(4-32) Sony Ericsson GSM Modem Configurations 77 VIII
  10. 10. Chapter One Introduction1.1 Overview The modernization of transport has become one of the essential signsfor the urban modernization level, the increase in the number of cars leads toserious problems concerning transport system. With the development of thetechnology of computer, communication, electron, information andintelligence has become important factors in achieving convenient andefficient transport system. According to these circumstances, the IntelligentTransport System (ITS) came into existence [1]. Collection of transportationinformation systems based on conventional detection techniques such as loopdetectors, video image processing, and Dedicated Short RangeCommunication (DSRC) leads to high installation and maintenance costs, thehigh costs prevented the proliferation of these detection techniques [2]. Radio Frequency Identification (RFID) technology is one of the mostrapidly growing segments of todays Automatic Identification Data Collection(AIDC) industry [3]. Using "RFID tags" on objects or assets, and "RFIDreaders" to gather the tag information, RFID represents an improvement overbar codes in terms of non-optical proximity communication, informationdensity, and two-way communication ability. It can automatically identifytarget and obtain relevant data without contacting with the target. It has manyadvantages such as high precision, easy adapting ability and quickly operationand so on. Moreover, it is able to work under harsh environment and readsfrom long distance [4]. 1
  11. 11. Automatic Vehicles Identification (AVI) system based on RFID isdesign for all legally registered vehicles; these vehicles must hold RFID tags.When these vehicles travel along a road or intersection which is installed AVIsystem (RFID reader), the information of vehicle tag is read and sentimmediately to Center Computer System (CCS) for achieving the purpose ofreal-time monitoring and management for vehicle movement conditions. TheCCS receives the information and position of the vehicle from trafficintersection and then analyzes and filters to store it in database [5].1.2 Literature Survey In an endeavor to enhance efficiency and safety in transport systems,research is being done in RFID applications in smart E-parking, tollcollection, virtual route tracking, digital traffic light control and with someother RFID applications. Several designs of such systems are given in thefollowing literature:  S. Tenqchen et al. in 2006 [6] proposed a website to exhibit the traffic information for every 5 minutes at certain places of street measured by three RFID readers for 125 tags installed on two different urban-bus companies and transmit that information via GPRS modem from testing point to control center. Each data can be used to indicate the exact point of traffic condition in a big city. Three different readers installed in certain places; those readers are used to collect traffic information by recording the tag’s information of incoming urban-buses. The result shows that the application of RFID tag and reader is an alternative way to extract the traffic information instead of traditional loop detector.  J. D. Tseng et al. in 2007 [7] proposed a vehicle management system based on UHF band RFID technology. The system is applied for 2
  12. 12. vehicle entering/leaving at road gates. The system consists of tag-on- car, reader antenna, reader controller, and the monitoring and commanding software. The entering time, leaving time, and tag number of each vehicle are all recorded and saved for further processing. The experimental results demonstrated the proposed system is reliable on this application. The system could not only reduce the cost of guard and payload in the maximum by the decrement of manpower, but also promote the security and efficiency of the parking lot. M. Kim et al. in 2008 [8] developed an active RFID - based national Traffic Information Collection System (TICS) in ubiquitous environments. RFID readers have been installed at 130 spots and operate as 65 pairs at road side to obtain speed and location of vehicles. Active RFID tags are attached to 2,000 vehicles including normal cars, taxies and buses. The tag information is sent to middleware in the central center through the communication network, processed and saved in database, and utilized by various traffic related applications. Experiments were performed for four months. As time goes, the number of recognized tag identifiers decreases quite fast due to battery failures, detached tags, and other reasons. K. A. S. Al-Khateeb et al. in 2008 [9] developed an intelligent RFID traffic control, to solve the traffic congestion problem. RFID technology with appropriate algorithm and data base were applied to provide an efficient time management scheme. The simulation result has shown that, the dynamic sequence algorithm has the ability to intelligently adjust itself even with the presence of some extreme cases. The real time operation of the system emulated the judgment of a traffic policeman on duty, by considering the number of vehicles in each column and the routing proprieties. The great challenge would be to 3
  13. 13. design a system that is capable of understanding and identifying traffic movement for a whole city. Understanding the routine traffic pattern can provide accurate information to the traffic planner or urban designer to develop a traffic jam free city. Y. Zhang in 2009 [10] proposed a framework in which moving vehicles with attached passive RFID tags can be located with RFID readers installed at the roadside near the road intersections thus to improve the ITS traffic real-time road status. A challenging issue in his approach is to avoid multiple RFID reader collision problems to ensure the integrity of traffic sampling data. The location information of road intersection is preloaded in RFID reader. By tracing individual vehicles’ information the system can evaluate the road status throughout the city. Implementations have been conducted to evaluate the feasibility of the proposed framework. H. He and Y. Zhang in 2009 [11] introduced a new method based on RFID technology to get the vehicle running state parameters. Vehicle traveling data recorder (which is also called automobile block box) can accurately record the state parameters of the automotive traveling process, which can offer a real, effective and scientific legal basis for the analysis of traffic accidents. The system adds RFID module on the base of the traditional vehicle traveling data recorder, which achieves non-stopping to get the vehicle’s running parameters on some section of highway. The tag module of this system adopts Mifare1 S50 card, the reader module uses MCM200 produced by PHILIPS Company; and the system takes Linux as the operating system. The results show that the system has a small volume, complete function, high reliability and high performance ratio. 4
  14. 14.  H. Tao et al. in 2010 [12] proposed management system optimized design to solve traffic intersection problems in the management of traditional vehicles. The system includes the hardware architecture and system software. At the four directions of the intersection (e.g. east, south, west, north), in each direction to set two RFID readers, they can simultaneously scan in the reverse direction from the two vehicles, and can record relevant information for each vehicle, including the vehicle electronic tag encoding and the driver electronic label encoding. Z. Feng et al. in 2010 [13] designed the vehicle path recognition based on RFID and an Electronic Toll Collection (ETC) system of expressway. The ETC system will toll collection without parking, also census traffic flow and audit road maintenance fees. It uses 920MHz passive RFID tag as carrier to identify actual vehicle path. High-speed long-distance UHF reader is installed in all sections of the monitoring points and highway entrances and exits, so as to automatically read the electronic tag information carried by the vehicles pass through the marking station, so that the system can record the driving path. Iswanjono et al. in 2011 [14] proposed an algorithm for predicting the speed of traffic light violators. The traffic light system is equipped RFID reader as the main tool for identifying the vehicles RFID tags. The simulation by Scilab simulator gives evidence of violation and prediction of vehicle flow. The violation can detect if the vehicles IDs have moved from one RFID reader to the others. A randomization generates vehicle IDs, vehicle numbers and vehicle branch destination that can show the function of RFID reader to detect tags. From the simulation conducted, the algorithm is able to predict the speed of traffic light violators ranging from 5 km/h up to 80 km/h in real-time. 5
  15. 15.  M. Yu et al. in 2011 [15] implemented active RFID tag based system for automatically identifying running vehicles on roads and collecting their data. The design principles and the architecture of the system includes active electronic tags and reading equipment (readers and antennas), the monitoring base station deployment, the two-layered network construction, and the monitoring software. The system used electronic tag and reading base station is based on SCM C8051F920; it is a low- power high-speed general with a 24.5MHz oscillator, and a programmable flash memory. The effectiveness and efficiency of the system is analyzed. The system will have wide applications in traffic IOT (Internet of Things) to support traffic monitoring, traffic flow statistics, traffic scheduling, and special vehicle tracking.1.3 Aim of the Work The aim of this work is to show how technologies of identification byRFID can be used to build VLS by collecting the traffic information in urbancities. This work is designed to monitor the traffic intersections in real-timevia RFID system. This will be applied in all intersections for each vehicle.This is achieved by installing RFID readers in the traffic intersections andattaching RFID tags in vehicles. Then, the VLS will use the acquiredinformation in several applications of ITS as the following:  Discovery the vehicles locations.  Displaying the route of the vehicle on the city map.  Monitoring the intersections.  Tracking vehicles color.  Tracking the illegal and robbed vehicles in real-time.  Estimating the status of congestion in roads and traffic intersections. 6
  16. 16. 1.4 Thesis Outline This thesis is organized in five chapters. The contents of the followingchapters are briefly reviewed as follows:  Chapter Two: This chapter explains RIFD technology and RFID system components like readers, tags and host system. Then specify the discussion on using RFID technology in transport systems.  Chapter Three: This chapter discusses the proposed VLS, VLS structure, the database of VLS, RFID simulation and the methods of VLS applications.  Chapter Four: This chapter discusses the implementation of VLS, SMS server and websites.  Chapter Five: This chapter includes conclusions and suggestions for possible future work. 7
  17. 17. Chapter Two RFID Technology and Applications2.1 Introduction RFID technology is currently being used in numerous applicationsthroughout the world [3]. RFID is not a new technology, for example, theprinciples of RFID has been employed by the British in World War II toidentify their aircraft using the IFF system (Identity: Friend or Foe) [16], andit is still being used today for the same purposes. RFID uses tags to transmit data upon RFID reader queries. RFID tagresponds to a reader query with its fixed unique serial number (tag ID). Thisfixed tag ID enables tracking of tags and the bearers. In addition to the uniqueserial number, some tags carry information about the objects they are attachedto [17]. RFID is used for a wide variety of applications ranging from thefamiliar building access control proximity cards to supply chain tracking, tollcollection, vehicle parking access control, retail stock management, trackinglibrary books, theft prevention, etc.2.2 RFID System Components RFID is a generic term for technologies that use radio waves toautomatically identify people or objects. There are several methods ofidentification, the most common of which is to associate the RFID tag uniqueidentifier with an object or person. RFID system (as shown in Fig. 2-1) willtypically comprise the following [4]: RFID tag. 8
  18. 18.  RFID reader with an antenna and transceiver. A host system or connection to an enterprise system. Figure 2-1 Components of RFID system [18]2.3 RFID Tags The tag, also known as the transponder (derived from the termstransmitter and responder), holds the data that is transmitted to the readerwhen the tag is interrogated by the reader. The most common tags todayconsist of an Integrated Circuit (IC) with memory, essentially amicroprocessor chip [19], see Fig. 2-2. Figure 2-2 Typical design of passive tag [3] 9
  19. 19. The implementation of a passive UHF RFID tag is shown in Fig. 2-3, ablock diagram of RFID tag using backscatter modulation. The tag consists oftag antenna and tag chip. The tag chip contains a RF-analog front end (voltagerectifier, clock generator, modulator and demodulator), a digital control block,and a non-volatile memory [17]. Figure 2-3 Passive UHF RFID tag block diagram [17] Other tags are chipless and have no onboard IC. Chipless tags are mosteffective in applications where simpler range of functions is required;although they can help achieve more accuracy and better detection range, atpotentially lower cost than their IC-based counterparts [19]. When a tag is interrogated, the data from its memory is retrieved andtransmitted. A tag can perform basic tasks (read/write from/to memory) ormanipulate the data in its memory in other ways [19]. RFID tags can interfere with each other. When multiple tags are presentin a reader‟s field, the reader may be unable to decipher the signals from thetags. For many applications, such as raising the gate in a parking lot, this isnot a problem. The systems are optimized so that only one tag is within rangeat a time. However, for other applications, reading multiple tags at once isessential, for these applications, the tags need to support an anti-collisionprotocol to allow each tag reads without interference from the others [20]. Aneffective anti-collision algorithm can reduce the operating time and increase 10
  20. 20. the read rate. Two algorithms, slotted ALOHA and binary search, are alwaysused in the RFID protocol. The slotted ALOHA algorithm needs asynchronous signal and a longer time to process when more tags are incollision. Also the discrimination ratio is not as high as that with the binarysearch algorithm. However, the binary search algorithm has strictrequirements for its computing slot and bad security [21].2.3.1 Tag TypesRFID tags fall into two broad categories: those with a power supply (abattery) and those without. RFID tag that actively transmitted to a reader isknown as „„active tags‟‟. Unpowered passive tags are known as „„passivetags‟‟. Active tags are typically also read/write tags while passive tags aregenerally read only. Active tags are larger and more expensive than passive tags. The use ofa battery places a limit on the life of the tag, although with current batterytechnology this may be as much as 10 years [4]. Passive tags have an unlimited life, are lighter, smaller and cheaper.The trade-off is limited data storage capability, a shorter read range and theyrequire a higher-power reader. Performance is reduced in electromagnetically„„noisy‟‟ environments. There are also semi-passive tags where the battery runs the chip‟scircuitry but the tag communicates by drawing power from the reader. Tags are available in a wide variety of shapes, sizes and protectivehousings. The smallest tags commercially available measure 0.4 x 0.4 mmand are thinner than a sheet of paper [4]. 11
  21. 21. 2.3.2 Tag operationIn LF or HF systems, tag-to-reader communication is achieved via inductivecoupling (load modulation). Load modulation is achieved by modulating theimpedance of the tag as seen by the reader. In UHF or above systems, tag-to-reader communication is achieved via propagation coupling (backscatter).Backscatter is achieved by modulating the radar cross section of the tagantenna [3]. In load modulation process, when a tag is placed within the alternatingmagnetic field created by the reader, it draws energy from the magnetic field.This additional power consumption can be measured remotely as a voltageperturbation at the internal impedance of the reader antenna. The periodicswitching on/off of a load resistance at the tag therefore affects voltagechanges at the reader‟s antenna and thus has the effect of an amplitudemodulation of the antenna voltage by the remote tag. If the switching on andoff of the load resistance is controlled by the tag‟s stored data stream, thenthis data is transferred from the tag to the reader. In load modulation thecarrier signal is modulated by switching impedance from a matched conditionto an unmatched condition to alter the reflection coefficient [3]. In backscatter modulation process, a reader sends a signal (energy) to atag, and the tag responds by reflecting a part of this energy back to the reader.A charge device such as a capacitor contained in the tag makes this reflectionpossible. The capacitor gets charged as it stores the energy received from thereader. As the tag responds back, it uses this energy to send the signal back tothe reader. The capacitor discharges in the process [19].2.3.3 Electronic Product Code (EPC) TagThe specifications for UHF passive tags and RFID readers developed first bythe Auto-ID Center and then by EPCglobal, a standards body that was formed 12
  22. 22. from the article-numbering barcode associations around the world, to promotethe use of RFID in commerce [21]. At the heart of the EPC suite of standardsis the EPCglobal EPC Gen2 protocol (as well as its counterpart ISO 18000-6c) that specifies the air interface protocol for communication betweenreaders and tags [3]. The EPC Gen2 protocol is a very powerful one with anumber of features almost unimaginable in a lower-cost tag even a few yearsago [21]. EPCglobal has defined a series of RFID tag “classes” and“generations” of RFID tags, see Tables 2-1 and 2-2. Table 2-1 EPC RFID classes [20] 13
  23. 23. Table 2-2 EPC RFID chip generations [20] The EPC tag data standard specifies the format for encoding andreading data from 96-bit RFID tags, as shown in Fig. 2-4. Figure 2-4 EPC tag content [4]2.3.4 Tag MemoryA tags memory attribute can be read-only (RO), write once-read many(WORM), or read-write (RW), see Table 2-1. Memory write capability 14
  24. 24. generally increases the cost of a tag, along with its capability to performhigher-level functions. At the same time, read-only tags eliminate the risk ofaccidental or malicious over-writing of tag data [19]. Tag memory configurations can vary greatly based on cost and physicalrequirements. In case of Electronic Article Surveillance (EAS), tags haveessentially 1 bit of memory and are relatively inexpensive when compared totags with more memory. These tags have no unique identifiers and are usedonly to signal their presence when they are in the field of a reader. Beyond the1-bit tags, typical memory footprints can range from 16 bits to severalhundred Kbits for certain active tags. The amount of memory present on a tagis then defined by application requirements and/or any relevant standards orregulations. For example, due to the expected global acceptance of theEPCglobal standards, the memory size for the newer generation of passivetags will be 2 Kbits or more [19].2.4 RFID Reader Reader, as a scanning device, detects the tags that attached to orembedded in the selected items. It varies in size, weight and may be stationaryor mobile. Reader communicates with the tag through the reader antenna, asshown in Fig. 2-5, which broadcasting radio waves and receiving the tagsresponse signals within its reading area. After the signals from tags aredetected, reader decodes them and passes the information to middleware [18]. The reader for a read/write tag is often called an interrogator. Unlikethe reader for a read-only tag, the interrogator uses command pulses tocommunicate with a tag for reading and writing data [3]. 15
  25. 25. Figure 2-5 Typical electrical connections for RFID reader RFID reader sends a pulse of radio energy to the tag and listens for thetag‟s response. The tag detects this energy and sends back a response thatcontains the tag‟s serial number and possibly other information as well. Historically, RFID readers were designed to read only a particular kindof tag, but so-called multimode readers that can read many different kinds oftags are becoming increasingly popular. Like the tags themselves, RFID readers come in many sizes. Thelargest readers might consist of a desktop personal computer with a specialcard and multiple antennas connected to the card through shielded cable. Sucha reader would typically have a network connection as well so that it could 16
  26. 26. report tags that it reads to other computers. The smallest readers are the sizeof a postage stamp and are designed to be embedded in mobile telephones[20].2.4.1 Energize the TagIn the case of passive and semi-active tags, the reader provides the energyrequired to activate or energize the tag in the readers electromagnetic field.The reach of this field is generally determined by the size of the antenna andthe power of the reader. The size of the antenna is generally defined byapplication requirements. However, the power of the reader (through theantenna), which defines the intensity and reach the electromagnetic fieldproduced, is generally limited by regulations. Each country has its own set ofstandards and regulations relating to the amount of power generated at variousfrequencies. For this reason, incompatibilities do exist between RFID systemsin various countries [19].EPCglobal and ISO created standards to solve this problem. EPCglobalinitiated the creation of a standard to facilitate full-scale interoperabilitybetween multivendor RFID systems and to propel RFID technology into abroad array of markets. EPCglobal established and supports the EPC as theworldwide standard for immediate, automatic, and accurate identification ofany item in the supply chain. EPCglobal is sponsored by many of the worldsleading corporations and it has published a set of RFID protocol standards(see sec. 2.3.3).Also, ISO is a network of the national standards institutes of 148 countries,making it more global and governmental than EPCglobal. ISO bridges theneeds of the public and private sectors, focusing on creating standards andbuilding universal consensus for the acceptance of those standards [19]. 17
  27. 27. 2.4.2 Frequency RangesOne of the more important aspects of a tag and reader connection (coupling)is the frequency at which it operates. Frequency allocations are generallymanaged through legislation and regulation by individual governments.Internationally, there are differences in frequencies allocated for RFIDapplications although standardization through ISO and similar organizationsis assisting in compatibility [4]. In general, the frequency defines the data transfer rate (speed) betweenthe tag and the reader. Lower frequency performs slower transfer rate.However, speed is not the only consideration in designing RFID solution.Environmental conditions can play a significant role in determining theoptimal operating frequency for a particular application. Higher frequency usually means smaller antenna, smaller tag size, andgreater range and typically, more regulatory of use restrictions and often,higher cost [19]. Table 2-3 summarizes the most popular frequency bands,and characteristics. Table 2-3 RFID frequency bands [16] 18
  28. 28. 2.4.3 Communication with the Host ComputerThe reader is also responsible for the flow of data between the tags and thehost computer. Typically the reader communicates with a host computerthrough a Serial or Ethernet connection. A reader may also be equipped tocommunicate with the host computer through a wireless connection,particularly if the reader is a portable or handheld device [19].2.5 RFID Antenna The reader antenna establishes a connection between the readerelectronics and the electromagnetic wave in the space. In the HF range, thereader antenna is a coil (like the tag antenna), designed to produce as strong acoupling as possible with the tag antenna. In the UHF range, reader antennas(like tag antennas) come in a variety of designs. Highly directional, high-gainantennas are used for large read distances [3]. Antenna design and placement plays a significant factor in determiningthe coverage zone, range and accuracy of communication [19]. Physicalinterdependencies mean that the antenna gain is linked to the antenna size.The higher the gain (or the smaller the solid angle into which the antennaemits), the larger the mechanical design of the antenna will be. All otherthings being equal, a high-gain antenna will transmit and receive weakersignals farther than a low-gain antenna. Omnidirectional antennas, such asdipole antennas, will have lower gain than directional antennas because theydistribute their power over a wider area. Parabolic antennas usually have thehighest gain of any type of antenna [3]. The tag antenna is usually mounted on the same surface as the IC andpackaged as a single unit. Fig. 2-6 shows several common passive tag andantenna configurations. Although the tag IC can be tiny (the size of a grain of 19
  29. 29. rice or smaller), the size and shape of the antenna typically determines thelimits of the dimensions of the entire tag packaging [19]. Figure 2-6 Typical passive RFID tags with different antennas [19] Let the power transmitted by the reader be and the gain of thereader antenna be Greader. The power density at distance R where the tag isplaced can be expressed asThe power received by the tag is calculated byWhereThen 20
  30. 30. The power density of the return wave from the tag at the position of the readerisThus the power received by the reader isThat isWhere Greader stands for the gain of the reader antenna, Areader the equivalentaperture of the reader antenna, Gtag the gain of the tag antenna, and Atag theequivalent aperture of the tag antenna.Where Effective Isotropic Radiated Power (EIRP) is the power transmitted bythe reader, the equivalent transmitted power asThenDenote by the threshold power of the sensitivity. Then the maximumreading range is expressed as 21
  31. 31. Now we analyze the RFID system by using the radar principle. Suppose thatthe backscattering section of the tag, including the antenna and the chip, isσtag, then the backscattering power of the tag isThe power density of the backscattering wave at the position of the reader isSo we haveBy adjusting the tag chip impedance according to the stored data in tag, σtagwill be changed, and then the return wave coming from the tag and receivedby the reader will be changed such that the amplitude modulation anddemodulation can be realized. In this manner, the tag information can be read,and the object detected by the tag can be identified [22].2.6 RFID Middleware A middleware, as the name suggests, is a piece of software that liesbetween a lower layer processing device or software and an upper layer serveror software, usually at the application level. Therefore, data from RFIDreaders are sent to a middleware platform that acts as a bridge between RFIDreaders and host application software [23] [24]. Typically, RFID middleware platform performs aggregation of dataacross different readers, filtering of unwanted or noisy RFID data, forwardingof relevant data to subscriber servers or application-level systems, andpersistent storage for context aware and other added value services. However, 22
  32. 32. RFID middleware is often given the task of managing, monitoring andconfiguring the different readers and interrogators. The middleware performsmonitoring task on RFID readers to check operational status of the readers.This is a very important function, especially when readers are located indistributed manner, and manual monitoring is impractical [23] [24].According to the main functionalities hosted by RFID middleware platformcan be classified as follows [23]:1- Configuration Service Set  Network interface configuration. Discovers and sets reader networking parameters and identity, e.g. the IP address.  Firmware management. Distribute and manage firmware version on readers  Antenna, tag population and memory selection. Specify reader antennas and tag population to be inventoried. In case of tag memory access, specifies memory fields to be accessed.  Base service set scheduling. Sets how different services, such as tag inventory, access, and deactivation, are triggered and stopped.  RF transmitter configuration. Sets transmit channel, hop sequence, and transmit power for readers.  Air interface protocol configuration. Configures timing, coding and modulation parameter of a specific air interface protocol on the readers.2- Data Processing Service Set  Filtering. Removes unwanted tag identifiers from the set of tag identifiers captured, e.g. based on the product type or manufacturer encoded in the identifier. 23
  33. 33.  Aggregation. Computes aggregates in the time domain (entry/exit events) and the space domain (across reader antennas and readers) and generates the corresponding “super” events.  Identifier translation. Translates between different representation of the identifier, e.g. from raw tag object identifier in hexadecimal format to EPC.  Persistent storage. Stores RFID data captured for future application requests.  Reliable messaging. Allow RFID data to be delivered reliably in the presence of software component, system and network failures.  Location/Movement estimation. Detects false positive reads of far- away tags that are outside the “typical” read range and estimate the direction of movement.  Application Logic execution. Interprets the RFID data captured in an application context and generate the corresponding application events, e.g. detect whether a shipment is complete.3- Monitoring Service Set  Network connection monitoring. Check that the reader can communicate captured RFID data over the network  RF environment monitoring. Check RF noise and interference levels to safeguard reliable identification operation  Reader Monitoring. Check that the reader is up, running and executing as configured for example via monitoring the number of successful/failed read and write operations.Now, not all these functionalities are mandatory to be hosted by themiddleware. This depends on the reader architecture employed. Two types ofarchitectures can be followed: one in which many of the above functionalities 24
  34. 34. are hosted by the reader itself, which will be called decentralized readerarchitecture, and the one in which all the functionalities, except the basic onesused in the reader, will be hosted by the middleware platform or a controllerappliance [23].2.7 Automatic Vehicles Identification (AVI) based on RFID AVI system based on RFID is a design that covers every vehicle legallyregistered which carries RFID tag. When these vehicles travel along a road inwhich AVI system is installed, all kinds of vehicles information of car tag isread and transmitted in real-time to data processing controlling unit realizingthe purpose of real-time monitor and management for vehicle operatingconditions [5]. The main components of the AVI system based on RFID include: (i)hardware, i.e. passive RFID tags and readers for generation of trafficinformation; (ii) RFID middleware and database structure, and applicationsoftware consisting of real-time process; and (iii) network architecture todeploy AVI system nationwide [8].2.7.1 RFID Hardware’s Properties RequirementsUsing RFID in AVI systems that requires specific properties for RFIDreader‟s devices to realizes the system requirements. The followingcharacteristics should be available in RFID reader for using it in AVI system: 1. Multi-tags recognition rate 2. High tag recognition speeds 3. Operating in UHF or higher frequency 4. Read only (not need writing in tags) 5. Large coverage distance, for 9 meters or higher 25
  35. 35. 6. The antenna is separated from reader‟s device (not incorporated with reader) 7. Support multi-static antenna system (transmit and receive) 8. Support for multiple antenna‟s ports, four or more 9. Support for Ethernet connection, TCP/IP2.7.2 Applications of SystemThe ITS based on RFID technology is a comprehensive managing system,which integrates information technology, communication technology,automatic control technology and information processing technology,combines traffic planning, traffic engineering and traffic management as awhole to enhance traffic capability. The communication between road andvehicles is one of the key technologies [1]. The application of RFID technology in ITS is widely utilized at the presenttime and in the future. The following list of applications of AVI system basedon RFID: 1. Electronic Toll Collection (ETC) System ETC system adopted in highways can solve many problems brought by traditional way of charging, such as time-consuming and inconvenience of supervision. The system can read the ID number from the vehicles affixed with RFID tags, and transmits the information to the manage center through network under the control of the RF controller, with the exact passing time and the driveway number. The ETC system will charge automatically according to the passing time and give green light to the cars with the effective tags, and hold up the cars without card or the null card [1] [25] [26]. 26
  36. 36. 2. Gate Automatic Identification System RFID technology could also be utilized in some military places, parking places, communities and confidential departments by adopting GAI system. When the vehicles affixed with RFID tags approach the driveway, the system can get the ID of RFID tags, and transmits the vehicles‟ information to the manage center. Then, the manage center decides whether or not give green light the vehicles, by means of sending control order to the executive machine. Under the surveillance of GAI system, it can identify all the passing cars and give green lights to the cars which have been registered (affixed with effective RFID tags), solving the problems often existed in the traditional way of household guards, which often causes big loss, inconvenience, and feelings of insecurity, etc. [1].3. Automatic Equipment Identification System AEI systems are mainly used in the identification of the containers, such as application to the sea, road and rail containers transport or logistics management with the advantages of both safety and convenience. RFID tags would be affixed to these containers, with the information of containers‟ number, quantity, and the shipping sites and its destination. Once the containers are shipped to the port of destination, AEI system would read the information via the automatic identification, and then exchange information with these tags [1].4. Vehicles Speed Estimation The speed of vehicle is estimated to check if vehicle exceeded the limited speed of street or not. The speed of vehicle is estimated based on measured detection time difference and distance between two readers. To estimate the velocity of the vehicle, two RFID readers must be installed [24]. 27
  37. 37. Figure 2-7 Estimation of velocity [24] As shown in Fig. 2-7, (d1) is the distance between reader A and the vehicle, (d2) is the distance between the readers and (d3) is the distance between reader B and the vehicle. Then, the velocity of the vehicle calculates as Where t1 and t2 denote the communication moment between readers and tags.Other applications of AVI system fall in many fields [5,27-30] such as smartE-parking, intelligent security management system, customs electronic licenseplate AVI system, public transport e-ticketing, missing and stolen vehicletracking system, virtual route tracking, TICS, traffic violation monitoring,variable speed limits, enhancement of driver‟s situation awareness, collisionavoidance systems, Intelligent Traffic Management System (ITMS), digitaltraffic light control, the data dissemination between vehicle-to-infrastructure(V2I) or vehicle-to-vehicle (V2V), etc. 28
  38. 38. Chapter Three The Proposed Vehicle Location System3.1 Introduction This chapter discusses the design of VLS which consists of CCS, SMSserver and websites. The CCS contains the middleware, database managementand the system applications. The RFID readers of VLS are simulated toevaluate the system works and test its ability to collect and manage the trafficinformation from several RFID readers in real-time. The middleware is programmed to connect the VLS with readers fromone side and with database on the other, and to arrange the information that isreceived from readers in appropriate format to be used in the applicationsystem and website. Wireless communication system is used to communicatethe CCS with readers.3.2 System Architecture The first step in the VLS is to attach RFID tag to all vehicles that canbe identified by RFID readers. It is suggested that the data is stored in tagonly be tag ID and without any other details of vehicle, so to keep the personsprivacy of the vehicles’ owners. In this form no privacy’s information isavailable, and if any snooper tries to install illegal reader to snoop, he cannotenter to the private information of vehicle owner, he will save the normalinformation like he records the information by sight to vehicle license plate. The VLS is composed of installing of two RFID readers in each trafficintersections, as shown in Fig. 3-1. The four branches of the traffic 29
  39. 39. intersection are North, East, South and West were represented as Road 1,Road 2, Road 3 and Road 4 respectively. In each branch set two RFIDantennas, they can simultaneously scan in the opposite directions from thetwo vehicles, and these antennas can record relevant information for eachvehicle. Figure 3-1 Architecture of traffic intersection in VLS In each branch, two antennas are installed in the mid island of the roadnear the traffic intersection, and separated by a convenient distance. In thisarchitecture of arranging the direction of antennas, each antennas RFradiation areas do not overlap each other. The RFID antennas are numbered as 0, 1, 2 and 3. The even antennasare installed on the ways-in of intersections while the odd antennas areinstalled on the ways-out of intersections. Hence, for reader 1 install antenna(0) is on way-in of road 1, antenna (2) is on way-in of road 2, antenna (1) is 30
  40. 40. on way-out of road 1 and antenna (3) is on way-out of road 2, so for reader 2in roads 3 and 4, see the simulation of traffic intersection in VLS in Fig. 3-2. Figure 3-2 Simulation of traffic intersection In CCS, according to the order of receiving the same tag ID from twodifferent antennas, the direction of vehicle movement will be known from itsentry and to its exit. In this architecture of the system, the VLS will monitorthe path direction for all vehicles in the traffic intersections in real-time. In the proposed VLS, RFID readers communicate with CCS viawireless network, RFID reader is connected with wireless station by STPcable, while the wireless access point is connected with CCS directly by UTPcable. The stations communicate with access point as shown in Fig. 3-3. 31
  41. 41. Figure 3-3 The communication method for VLS system3.3 System Structure The VLS components are divided into two parts: software andhardware. The software part is implemented while the hardware part issimulated. The software part is programmed by using (Microsoft Visual Basic2010 program) that works in (Microsoft .NET Framework 4.0) environmentand the large database system is designed by (Microsoft SQL Server 2008 R2Management Studio). The hardware part of VLS consists of RFID readers and tags, wirelessnetwork, CCS, GSM modem, databases storage memory and cables. In VLS, the RFID readers are simulated by the use of Rifidi Platform(see sec. 3.4) and Roads and Traffic Intersections Simulation (RTIS) (see sec.3.5).In brief, the following components are used for building VLS system: 32
  42. 42.  Two computer devices (one as RFID reader(s) via Rifidi and/or RTIS simulators and another for CCS)  Wi-Fi system  Microsoft Visual Basic 2010 with .NET Framework 4.0 and Microsoft ASP .NET Web Site Designer.  Microsoft SQL Server 2008 R2 Management Studio  Sony Ericsson GSM Modem3.3.1 The VLS MiddlewareThe middleware is the software program (see sec. 2.6) used to establish theconnections with several RFID readers synchronous and communicate withthem. On the other side, it connects with SQL Server Management Studio tocommunicates with database.To connect VLS to RFID reader the middleware must have the following: 1- Traffic Intersection ID 2- RFID reader IP and Port 3- RFID reader Username and PasswordTo get this information, the system should communicate with the databaseand request this information from Traffic Intersections Table (see sec. 3.3.2).After getting the traffic intersection ID, IP, Port, Username and Password, thesystem will achieve connection with that reader. After the connection isaccomplished, the system sends (Get TagList) request. The reader will replyby the list of tags that is gathered from antennas. Each tags information issent as a form of one packet, see a flowchart in Fig. 3-4. The packet information is filtered as tag ID, antenna number, date andtime. This information will be stored in Data Online Table. Then check antenna number whether even or odd (see sec. 3.2). If theantenna number is even, the packet data are stored in temporary table, and if 33
  43. 43. the antenna number is odd, the system requests to search in temporary tableon that tag ID. When fetch the even packet with odd packet, the system inferthe vehicle ID from tag ID that is passed through, traffic intersection ID,from-road, to-road, date, in-time and out-time. The inferred information willbe stored in the Vehicle Location Table. The next step is to check whether this vehicle ID is in Black List Tableor not. If this is detected, the system displays warning message that thevehicle passed through the traffic intersection ID, from-road, to-road, date,and time. Then, the following step checks the connection with that reader if stillconnected or not. If not, the system will display (The reader -ID- isdisconnected or turn off) message. 34
  44. 44. StartLoad from database: Reader’s IP, Port, Username and Password Connecting with reader via socket Connection No Display: Can’t established? connect to reader Yes Display: Login Successfully 1 Send: Get TagList Receive: Tag List Yes No tags? NoAnalyzing data into:Vehicle IDs, Date, Time and Antenna No. Storing data in data online table 2 3 35
  45. 45. 2 Yes Is antenna Storing in no. even? temporary table No Looking for vehicle ID in temporary table No Display: ID found? Miss Data YesStore in vehicle location table: VehicleID, Intersection ID, from-road, to-road, date and time (in-out) Looking for vehicle ID in black list table Yes Display: ID found? Warning No Connection Yes 1 Status: OK? No Display: Reader is disconnected or turned off 3 End Figure 3-4 The flowchart of the middleware performance 36
  46. 46. 3.3.2 DatabaseAll RFID systems require smart database for storing all data received fromreaders in real-time. Microsoft SQL Server 2008 R2 Management Studio wasselected to build the VLSs database, as it is robust compatible with MicrosoftVisual Basic 2010 and Visual Basic support special Application ProgrammingInterface (API) command to communicate with it. Also SQL has fast responseand effective with robust request such as in one instruction that can querymany tables. Besides, SQL Server can have enough large database size forVLS. It supports databases’ size over a terabyte [31]. SQL Server is necessary to build several tables for VLS system, eachone for specific purpose. These tables are: traffic intersections table, vehiclestable, data online table, vehicle location table, black list table and authorizedusers table. Traffic Intersections TableThis table is constructed to define each intersection by a unique ID and eachintersection must have eight records (if the intersection has four roads) todefine all ways and antennas’ number that are installed in them. The traffic intersections table has all the information aboutintersections. It has the intersection ID, intersection number (from 0 to 7 if theintersection has four roads), the region of the traffic intersection within thecity as (Baghdad/Al-Mansur), the IPs and Ports of the readers that areinstalled in that intersection, the number of antenna on the road, the road isgoing to any intersection ID (if possible) and the distance between them, andthe Username and Password of readers. Besides, through the traffic intersections table, the system can definethe number of roads meeting in intersection, whether the intersection hasthree, four, five or more roads. Also, if the road is one or two ways, that 37
  47. 47. depends on the number of records and the distribution of antennas in ways.For example, five roads meeting in the intersection, VLS must have threeRFID readers and ten antennas, one of these readers have two antennas onlyand they are numerated (from 0 to 9). Vehicles TableThis table is used to register all vehicles’ information and properties. Thevehicles table contains the vehicle ID, the vehicles owner, vehicles type,vehicles description, vehicles color, vehicles model, the engine number ofvehicle and the tag ID that is attached in the vehicle. The vehicle ID is a unique ID for each vehicle and consists of the citythat this vehicle is registered in, the number of this vehicle and the type ofnumber. The number type is P as Private (the plate’s color is white), L asLoad (the plate’s color is yellow), T as Taxi (the plate’s color is red) or Govas Government (the plate’s color is blue) and it takes the first character fromthe name of any ministry. The vehicle ID form is (city/number/type), for example:(Baghdad/1234/P) the city is Baghdad, the number of the vehicle is 1234 andthe number type is Private that has white color. Other example:(Gov/4321/H), H as Ministry of Higher Education and Scientific Research. Data Online TableThis table is constructed to keep all the useful data received from readers. Itkeeps all the information of tag recognition arrived online to CCS as tag ID,the reader IP and Port that sent this tag, antenna number, the date and time ofdetection. 38
  48. 48. Vehicle Location TableA vehicle location table is an important table because it keeps all the inferredinformation by middleware. It keeps information of vehicle path in allintersections for each vehicle. The vehicle location table records the vehicle ID that passed throughspecific intersection ID, from-road number, to-road number, the date and theentry time and the exit time from intersection. Black List Vehicles TableThe black list table is used to enable the administrator to monitor set ofvehicles ID. Also, it will enable the administrator to add and delete vehicle’sID. The black list table has set of vehicles ID with their tags ID and the dateof the addition these vehicles in black list table. Authorized Users TableThis table is constructed to secure and protect the information of VLS fromanyone unlicensed that may be penetrating VLS system and destroying asystem and database. The authorized users table consists of set of pairs asadministrators name and passwords.3.4 Rifidi Platform Rifidi is the premier open source simulator for RFID. It enables todevelop RFID system entirely with software components and remove thedependency on hardware and infrastructure that RFID typically demands.Furthermore, Rifidi is implemented in Java and it is possible to download thesource code and modify it. 39
  49. 49. Rifidi makes it possible to Virtualize the RFID infrastructure withsoftware that defines RFID Readers, RFID Tags, and RFID Events thatbehave like their real-life counterparts [32]. This Rifidi development project was born when a team of industrialengineers tried to implement a client for 10’s a readers and they were stuck bythe complexity of this task. After discussing with many software developmentcompanies and RFID experts they realized that RFID simulation tool wouldbe appreciable for testing applications. Since that, in March 2006, this team ofdevelopers and RFID consultants started to work on this RFID simulationproject [32]. Rifidi is a complete RFID application platform; it allows the virtualcreation of RFID-based scenario while being sure that the software created forthis purpose will run as it is also in the real world. Indeed, Rifidi is a programthat simulates the reader/client interface of RFID reader. This means that aclient communicates with the Rifidi reader in the same way that it wouldcommunicate with a real reader. For example, with the Alien reader, a clientwould send messages to retrieve tag reads. The virtual Alien reader in RifidiEmulator responds to messages in the same way a real Alien reader does [33]. Rifidi team provided several software programs; each one has itsproperties and design for specific case. The programs are Rifidi Edge serverand client, Rifidi Designer, Prototyper, Rifidi Emulator and Rifidi TagStreamer. In VLS tests, two Alien ALR-9800 readers are considered that havefour antennas, as intersection readers and also several RFID tags are created.The RFID tags are represented as vehicles. The operations with Rifidi can be divided into two parts: connectionand send/receive data. In the first part, the connection is started between themiddleware and virtual readers. In fact, CCS will manage these readers and 40
  50. 50. will set the connections. In the second part, the virtual readers reply (GetTagList) request by sending the tags list to CCS at each second. In VLS, the both Rifidi Emulator and Rifidi Tag Streamer are used fortesting the system. Rifidi Emulator is used to test the middleware connectionprotocols in communication performance with Alien ALR-9800 Reader andto test sending the request (Get TagList) at each second and receive the reply(the tags) from the reader. Also, Rifidi Tag Streamer is used to test the robust of VLS middlewarein filtering the data that are received from readers at real-time and stored it indata online table.3.5 Roads and Traffic Intersections Simulation (RTIS) Before introducing VLS in a real-life, the ability, functionality,efficiency, and further effects have to be tested carefully. To evaluate theimprovements that can be achieved, the simulations have to be done.3.5.1 The RTIS ArchitectureA realistic simulation of roads and traffic intersections scenarios is needed.Various parameters are needed to simulate the traffic, the application, and theenvironment. Traffic includes the physical movements of vehicles on an arbitraryroad network. Application simulation means the simulation of applicationsthat are to be integrated in real world vehicles. For this purpose, inner vehicleinterfaces have to be emulated to allow the application to interact with RFIDreaders, as attached RFID tag on vehicles. The last part is the environmentsimulation which includes the roads network with traffic intersections. Also, TCP/IP server is built to simulate connection method in RTIS as 41
  51. 51. Alien ALR-9800 Enterprise RFID reader. The VLS connection with RTIS islike the connection with real Alien readers.3.5.2 The RTIS ScenarioTo evaluate the effectiveness of the VLS and to identify potential problems, asimulation scenario is selected as uncomplex as possible. For this reason, aspecial region is assumed. This region has nine in-out ways and five trafficintersections. One intersection is composed of three roads intersected and theothers are composed of four roads intersected. This region is chosen becauseit provides a good road structure for VLS tests. The assumed region is calledAl-Mansur in VLS simulation. The intersection ID is given to each intersection as sequence 146, 147,…,150. Ten RFID readers are simulated, two readers to each intersection.Each reader has IP and Port as sequence,,....,, as shown in Fig. 3-5. Seven vehicles are simulated and each vehicle is given specific vehicleID, tag ID and color. These vehicles move on the road network in randompath. Several routes are designed for each vehicle on road network. Thevehicle selects specific route which will pass through it by using randomfunction (that is supported in Visual Basic program). The random functiongives a random value, by depending on this value RTIS will decide the routethat the vehicle will pass. 42
  52. 52. Figure 3-5 The vehicles and roads network in RTIS Specific car can be activated in the test to simplify tracking itsinformation in VLS by selecting the car check box, or activate all cars to testthe ability of VLS system. Also the speed of vehicles moving can becontrolled in RTIS. The RTIS simulates RFID reader scanning and receiving tag ID fromvehicles. The virtual reader accumulates these data until it receives (GetTagList) instruction from VLS. Then, it will send the gathered data to VLS inCCS by TCP/IP server. To illuminate the data sent to VLS, RTIS displays all data that aregathered in the readers and will send them online to VLS in table. This tabledisplays the vehicles tag ID that is captured by a reader, readers IP and Port,the number of antenna, the date, and the time of capturing tag ID, as shown inFig. 3-6. 43
  53. 53. Figure 3-6 The gathered data Also, RTIS displays the meaning of these data that will be concluded inthe middleware of VLS as vehicle ID, intersection ID, from-road and to-roadin another table, as shown in Fig. 3-7. Figure 3-7 The significance of the gathered data The RTIS is designed for creating a scenario that is as real as possible.All the unnecessary or unpredictable factors that can influence the resultssuch as side roads traffic or complex traffic light systems are avoided in orderto provide significant results. 44
  54. 54. 3.6 RFID Readers Connection Protocols Alien ALR-9800 Enterprise RFID Reader supports Serial port (RS-232,DB-9 F) and TCP (LAN, RJ-45) connections. Serial connection is not usefulin VLS because the readers are distributed on large area. A TCP connectionprovides DHCP, TCP/IP and SNMP network protocols. When a CCS needs to connect to RFID reader in wide area networksuch as the Internet, it uses a software component called a socket. The socketopens the network connection for the middleware, allowing data to be sentand read over the network. It is important to note that these sockets aresoftware, not hardware. The socket interface is originally developed in UNIX to provide aninterface to the TCP/IP protocol suite. Internet socket, network socket orsocket is used for inter-process communication. A socket is one end of a two-way communication link between two programs running on the network. Asocket address is the combination of an IP address and a port number [34].Sockets are used to represent the connectivity between client and server. Fig.3-8 shows the connection between client and server on specific port. Figure 3-8 The connection between client and server on specific port [35] Normally, a server runs on a specific host (RFID reader in VLS) andhas socket which is bound to a specific port number. The server waits from 45
  55. 55. client side for listening to the socket and makes a connection request. On theclient end (the middleware in VLS) the client knows the IP address of theserver and the port number of the server listening. Making a connectionrequest the client program tries to negotiate with the server program on the IPaddress and port number. When connection is established between server andclient, client used that socket to communicate with server (read/write) [35].3.7 The Methods of VLS Applications VLS has several applications; these applications infer the usefulinformation from VLS data in database. The VLS applications display theresults in tables, figures or as reports. The following, the methods those usedin VLS applications.3.7.1 Tracking Method for Vehicle MovementThe theoretical basis of virtual route tracking (VRT) algorithm is that theinterrogation range of RFID system is very short as compared to the distancebetween readers. So, the position of the corresponding reader is used to standfor the current position of tag (vehicle). Figure 3-9 Principle of VRT algorithms [36] In Fig. 3-9, the black points stand for RFID readers and the matrix isRFID reader network (assume each reader or point represent one traffic 46
  56. 56. intersection). As the figure depicts, when a tag moves from reader (1, 1) toreader (2, 2), the straight line between them is regarded as the track of the tagby us. The virtual line (VRT) in figure is defined as the track of the tag. So,the track in the figure is:Track = Virtual Route: (1,1)→(2,2) → (2,3) → (1,4) → (2,5) → (3,5) → (4,4)→ (4,3) → (3,2) → (4,1) It is noted that, when a reader interrogates one tag, the next readerinterrogating it along the track must be adjacent to the previous reader. It isobvious in Fig. 3-10 that the tag at (2, 3) cannot jump to (2, 5) directlywithout activating reader (1, 4), (2, 4) or (3, 4). Therefore, VRT algorithmmust choose adjacent readers along the track [36]. The hierarchical structure of vehicle location over RFID reader networkis constructed and dynamically maintained while the vehicle is moving along.Exploiting the inherent spatiotemporal locality of vehicle movements, thishierarchy enables the system to conservatively update the vehicle locationinformation of moving vehicle only in adjacent traffic intersections [37]. Of course, real-world RFID reader network is impossible to placereaders so regular (exactly like a matrix) and previous figure here only depictsfundamental of this algorithm theoretically. In VLS, the VRT is used and the route is displayed in table or drawingthe path on region map. The vehicle path map application will be explained;the system calls the vehicle ID, region of search, date and period of time fromGUI. The system will be connected with database for request that vehiclepassed through any traffic intersections IDs and also from where it is comingand to where it is going. Then, the intersections ID organized as First,Second…. etc. depending on sequence of time appeared in database. After thesystem got all the information about that vehicle at that period of time, thesystem would call graphics functions to draw the VRT of a vehicle on a map 47
  57. 57. of this region. First draw from-road then draw to-road in each intersection, seeFig 3-10. To recognize the direction of VRT, i.e. the beginning and the endingof path, the system will draw the last intersection with blue color. Figure 3-10 The flowchart for drawing the VRT on the map 48
  58. 58. 3.7.2 Estimation of Traffic CongestionReporting road traffic congestion can be a confusion task since there aredifferent algorithms measuring congestion. Typical users need a concisenessand easiness to understand traffic report. The normal traffic situation can be roughly categorized into two states,open and congestion [38]. But it is observed that such a classification is notenough to describe the traffic situation. Thus, in VLS three traffic patterns areused to facilitate quickness and easiness to understand report [39]. NamelyRed (Traffic Jam), Yellow (Slow Moving), and Green (Free Flow) are definedas the following: 1. Traffic Jam: there are large numbers of vehicles and almost all of the vehicles run very slowly and it will be represented as red color. 2. Slow Moving: there are many vehicles and most of the vehicles run at half speed and it will be represented as yellow color. 3. Free Flow: there are few vehicles and the vehicles run at normal speed in the region of interest and it will be represented as green color.To determine a congestion level, three steps are applied to estimate thecongestion status: 1) Compute the average time spent, 2) Compute theaverage speed of vehicles and 3) Determining the final congestion level that iscompatible to the current system and ready to be reported to the public.Next, each procedure will be explained in detail. 1. Compute the Average Time Spent To compute the average time that is required to pass the road, the first step the system gets the time from GUI. Then, the system goes back five minutes past. Therewith it requests vehicles’ IDs that went out from road within these five minutes. The next step, the system calls the entry time to road for those vehicles. Then, it subtracts the exit time 49
  59. 59. from entry time for each vehicle, see Fig. 3-11. The last step is computing the time average via sum the spent time of all the vehicles and divides it on the number of vehicles. 2. Compute the Average Speed of Vehicles The system will compute the average speed of vehicles after it gets the distance of the road from traffic intersections table [24]. The system computes the average speed of vehicles via dividing the distance on average time spent. 3. Determining the Congestion Level After the system obtained the average speed of vehicles in road, the next step, congestion levels are classified using speed into three levels: red, yellow and green. The VLS uses two classifications thresholds, γ and δ for adjusting parameters of the algorithm, as follows [39]:  Green level, if average speed is larger than or equal γ.  Yellow level, if average speed is less than γ and larger than δ.  Red level, if average speed is less than δ.At the end, the user obtains from the system the average required time to passthe road and the average speed of vehicles in the last five minutes as well asestimating the traffic congestion level. 50
  60. 60. Figure 3-11 The flowchart for traffic congestion estimation3.8 VLS Client Access The VLS collects and stores the data in a database; these are privatedata and can only be entered by an administrator. But some information inVLS applications the user can access them by internet or cellulartelecommunications (GSM Mobile). The internet pages can be uploaded byweb servers such as Apache server, IIS server (Internet Information Server) orany other web server. 51
  61. 61. Cellular telecommunications through GSM network must be supportedby modem device. Wireless modems are the modem devices that generate,transmit or decode data from a cellular network for establishingcommunication between the cellular network and the computer. Wirelessmodems like other modem devices use serial communication to interface withthe computer (any microprocessor or microcontroller system) [40]. A GSM modem is a wireless modem that connects a computer to aGSM network. Like a GSM mobile phone, a GSM modem requires a SIMcard in order to operate. Fig. 3-12 shows the established communicationbetween the cellular network and the computer via GSM modem. Figure 3-12 GSM modem communications [40] An external GSM modem is connected to a computer by a serial cable.It is possible to make and receive phone calls and send text messages SMS(Short Message Service). AT commands must be used for establishing communication betweenthe GSM modem and the computer [40]. AT is the abbreviation for Attention,AT commands are the set of commands that are specified for controlling aGSM phone or modem and managing the SMS feature of GSM. The ATcommands are sent by the computer to the modem. The modem sends back anInformation Response, which is followed by a Result Code. The result codetells about the successful execution of that command. If an error occurs in the 52
  62. 62. execution of a command, an error result code is returned by the modem andthe execution of the command line is terminated [41]. The mode of modem can be either text mode (available on somemodems) or Protocol Description Unit (PDU) mode. In text mode, headersand body of the messages are given as separate parameters. PDU mode isexecution command sends message from a terminal equipment to thenetwork. The PDU shall be hexadecimal format and given in one line; phoneconverts this coding into the actual octets of PDU [41]. In VLS, the Sony Ericsson Mobile Phone Modem AAD-3880020-BVis used, that has the Sony Ericsson built-in modem software. The VLS modemis programmed by AT commands with PDU format mode. It is used tosend/receive SMS message with the user (the driver). 53
  63. 63. Chapter Four Implementation of Vehicle Location System4.1 Introduction The VLS programs are implemented by applying the proposed methodsand algorithms that were explained in the previous chapter. These areachieved using Visual Basic, ASP.Net Web Site and SQL ServerManagement Studio. This chapter will discuss all parts of these programs andhow they can be used, as well as the chapter will discuss system applications,SMS server and websites.4.2 Vehicle Location System VLS is composed of three parts which are main program, SMS serverand websites. The main program comprises the middleware, databasemanagement and applications. The middleware controls the connection andcommunication all RFID readers and database with CCS, as shown in Fig. 4-1. The database management organizes the data and allows user to add,update and modify records in tables. All VLS applications depend on the datareceived from RFID readers. 54
  64. 64. Figure 4-1 The layout of the VLS environment The implemented VLS, which includes main program of VLS, RTISand Wi-Fi system, as shown in Fig. 4-2. Figure 4-2 The implemented VLS 55
  65. 65. 4.3 The Main Program of VLS The main program is the CCS program; it is used to control RFIDreaders, and manage the database and VLS applications. Fig. 4-3 shows themain form of the VLS which has buttons to link all parts of the system. Eachbutton will be explained in the following subsections. Figure 4-3 Main form of VLS4.3.1 The VLS SecurityAfter running the VLS program, the user name and password form appears asshown in Fig. 4-4. This form is necessary to avoid accessing the VLS by anunauthorized person. The administrator must know the user name and thepassword. The default for both user name and password of VLS is (admin). Ifanyone tries to use invalid user name and password, an error message willappear. To let this program to be more flexible and more secure, the VLS hasthe ability to change the password (see sec. 4.3.3). Figure 4-4 The security form 56
  66. 66. 4.3.2 The VLS TablesVLS system contains six tables in database (see sec. 4.4.2). Specific GUIforms are designed to display the content of VLS tables. The first table is the traffic intersections table, which defines all theintersections and RFID readers which are installed in these intersections, asshown in Fig. 4-5. The columns of usernames and passwords of RFID readersare not displayed in this form because they will be displayed in RFID readerstable (see sec. 4.3.4). To enter the traffic intersections table formIntersections button in main form of VLS must be pressed on. Also, to returnback the Back button should be pressed on. Figure 4-5 Traffic intersections table The vehicles table is an important table in the system because VLSdepends on it to recognize whether the received tag ID from reader belongs toa vehicle or other object. This table contains all the information of vehicle andits owner, as well as the ID of tag that is attached in vehicle. This table mustcontain the information about all the vehicles in different cities. GUI of 57
  67. 67. vehicles table as shown in Fig. 4-6 . To open this form, Vehicles button in themain form of VLS should be pressed. Figure 4-6 Vehicles table The data online table keeps all tags IDs received from readers. Thistable is used when there is loss in some information or tag ID is not detected,e.g. if the vehicle is detected on entering the intersection and VLS could notdetect it on leaving the intersection for unknown reason. This vehicle ID isnot saved in the vehicle location table (see sec. 4.4.1), data online table willbe used to prove a vehicle passed through that intersection at that date andtime. Via clicking on Data Online button in the VLS form, the GUI of dataonline table will show, as shown in Fig. 4-7. 58
  68. 68. Figure 4-7 Data online table In VLS project, all the gathered data must be analyzed and filtered. Atthe end all concluded information will be saved in vehicle location table. Allthe paths of vehicles are stored in this table and the date and time of in andout. To access the GUI of the vehicle location table, Vehicle Location buttonshould be clicked on, as shown in Fig. 4-8. Figure 4-8 Vehicle location table 59
  69. 69. The form in Fig. 4-9 shows the black list vehicles table and two buttonsfor adding and deleting vehicle ID. Figure 4-9 Black list vehicles table The black list vehicles table is used to monitor in real time the illegaland the stolen vehicles by adding vehicle ID to the table. Fig. 4-10 shows thevehicle that is detected in real time. Figure 4-10 The vehicle which in black list is detected 60
  70. 70. To delete any vehicle ID from black list table, Delete Vehicle buttonmust be clicked on. Then, text box will appear to write the ID of vehicle thatneeds elimination from black list, as shown in Fig. 4-11. Figure 4-11 Deleting vehicle ID from black list table By clicking on Tables Update button in the main VLS form, the formin Fig. 4-12 will appear. This form gives the ability to the user to add, updateand modify traffic intersections and vehicles tables. Figure 4-12 Tables update form 61
  71. 71. To update traffic intersections table, Intersections button should beselected. Through this form the user can add, delete and modify records ofintersections table via using Navigator Tool, as shown in Fig. 4-13. Returnbutton is used to return to tables update form. Add New Records Delete Record Save All Updates Figure 4-13 Update of traffic intersections table By selecting Vehicles button, the update form of vehicles table will beopened, as shown in Fig. 4-14. 62
  72. 72. Figure 4-14 Update of vehicles table4.3.3 Setting Database and AuthorizationVia clicking on Setting button in the main form of VLS, the form in Fig. 4-15will appear. This is an important form because it can store the database asarchive and clean the tables that are automatically and continuously update(i.e. Data Online and Vehicle Location Tables). Figure 4-15 Setting database and authorization 63
  73. 73. By clicking on Backup Database button, the "Save File" dialog boxwill appear to specify the place to store backup database file. After backupdatabase file is stored, a message (Backup database is created successfully)will be displayed. By clicking on Backup and Cleaning button, the VLS will createbackup database and clean data online and vehicle location tables. Aftercompleting the backup and cleaning tables, the message in Fig. 4-16 will beshown. Figure 4-16 A message of cleaning tables successfully By clicking Restore Database button, the monition message (Therestoring operation will delete the current data in database) will be shown, asshown in Fig. 4-17. Then, by clicking on yes button, the "Open File" dialogbox will be appeared to specify place of backup file of database. Therestoration operation may need few minutes to be completed. 64
  74. 74. Figure 4-17 Restore database To allow the program to be more flexible and more secure, VLS givesthe ability for the administrator to change the password by clicking onChange Password button, then Fig. 4-18 will be shown. The old and newpassword must be entered in the form. After pressing the Save Changebutton, a message (Changing Password Successfully) will appear. Figure 4-18 Password change form 65
  75. 75. 4.3.4 The Connection with RFID ReadersThis is a presentation form of the middleware. By this form RFID readers canbe connected or disconnected. Also, the performance of readers can bemanaged and monitored in real-time. As well as monitoring the numbers oftags that are received and compared with the number of the tags that arefiltered and stored in data online table. To enter this form, Connect ToReaders button in main form of VLS should be clicked on, as shown in Fig.4-19. Figure 4-19 The connection form with RFID readers To connect with reader, the administrator must enter IP, Port, UserName and Password of reader and select its check box (as shown in Fig. 4-19). Then, by clicking on Connect button, the system will initialize theconnection and display if the connection is successful or failed. Thedisconnection of any reader is achieved by selecting its check box and clickon Disconnect button. If this reader is already disconnected a monitionmessage will be displayed. 66
  76. 76. When VLS project is running, if any readers connection is shutirregularly, the VLS will display a warning message as shown in Fig. 4-20. Figure 4-20 The connection shutdown irregularly The RFID Readers button will open a new form to display theinformation of traffic intersections readers. These are subset of informationthat is stored in traffic intersections table, as shown in Fig. 4-21. Figure 4-21 RFID readers table 67
  77. 77. The Conn. Show button in Fig. 4-20 will display a new form to showthe connection stream, as shown in Fig. 4-22 Figure 4-22 The connection stream Also, the Display button will show statistics for the numbers of tagsthat are received and the numbers of the tags that are filtered and stored indata online table.4.3.5 The Traffic Congestion AppraisalThe VLS system supports some applications for the data that are gathered andanalyzed. Most of these applications depend on vehicle location table. Thetraffic congestion appraisal is one of them. This application can estimate thecongestion in two conditions: along the street or within the intersection. Via click on Intersection Status button in the main form of VLS, theGUI of intersection congestion appraisal will be shown, as shown in Fig. 4- 68
  78. 78. 23. Appraisal of traffic intersections congestion is used to estimate therequired time to cross the intersection. It calculates the average of the requiredtime to cross the distance between the antenna of entry and the antenna ofexit. This application uses only the first step of Estimation of TrafficCongestion method (see sec. 4.8.2). The traffic intersection ID should be entered in its specific field. Thecongestion can be appraised for the time being (default) or at previous dateand time by selecting its button then specifying the date and time. The suggested system uses α and β criteria to estimate the status ofcongestion in intersection. The system enables α and β to be changed by theuser, via click on Setting button that activate its texts boxes. α and β are thetime range that are required (in seconds) to cross the intersection. By clickingon Congestion Status button, the system will compute and display results asthe number of vehicles passed through the intersection in the last fiveminutes, average of the required time to pass this intersection (in seconds) andthe intersection congestion status as Free Flow, Slow Moving or Traffic Jam. Figure 4-23 The traffic intersections congestion appraisal 69
  79. 79. Via click on Street Status button in main form of VLS, the form in Fig.4-24 will be appeared. The street congestion appraisal is very importantapplication of VLS. By this application the street congestion status can beestimated in real-time. The user must specify the street and the direction of traffic. This isdone by giving the ID of the intersections i.e. from-intersection to-intersection. The time must be specified at the present time (default) or on theprevious date and time by selecting its button then specifying the date andtime. In this application, the system uses γ and δ criteria to decide status oftraffic congestion in street, γ and δ are the range of vehicles’ speed criteria (inkm/Hr) that pass through street. VLS system enables the user to change γ andδ, via click on Setting button that activate its texts boxes. Figure 4-24 The street traffic congestion appraisal This application uses all steps in the method of Estimation of TrafficCongestion. By clicking on Congestion Status button, the system will displaythe required time average to pass that street, the speed average of vehicles thatpassed through the street and the street traffic congestion status. 70