2. 3. 4. 5. 1.
2. 3. 4. 5. I. VANET ROUTING PROTOCOLSNow coming todifferent routing protocols, VANET routing protocols can be classified into 5broader categories which also have their subdivisions. The classification is doneon the basis of the route update methods and the positions. Figure 7:Routing protocol hierarchy 101.
POSITIONBASED ROUTING: The communication between source and destination node uses thegeographical location rather than the network address. The exact position ofthe nodes which took part in the communication can be accessed via periodicallytransmitted beacons 11. GPS is the necessity of the protocol to determine thelocation of different vehicular terminals. They can work easily withoutestablishing or maintaining routes. They can be further classified into 2parts: a. GREEDY PARAMETER STATELESS ROUTING (GPSR): GPSR makes use of the geographical location.
Each node has the knowledgeof the corresponding neighbour and it chooses the next hop which is nearest tothe respective destination. This procedure is known as greedy forwarding. Theconcept of HELLO messages comes into the picture in this procedure, if theHELLO message is not captured from the corresponding node then it assumes thatthe neighbour is out of the respected area 12b. DISTANCE ROUTING EFFECT ALGORITHM FORMOBILITY(DREAM): This Protocol isbasically used in unformed architectures. Each terminal maintains a Positiontable which has the location of all the nodes present in the network and thus aposition Packet is updated on a regular time interval. A packet delivery rateis dependent on the speed of the respective source node 13. Figure 8:Mobility Scenario 13 Figure 9:Intersection Structure 13 PROS CONS 1.Position based routing protocol is suitable in highway because of high mobility of the vehicles and less obstacles 10 2.
There is no need to maintain the routing table and thus overhead is low. 3. The latency is low in this protocol. 1.Gps is the necessity of the protocol, if GPS is not working than this protocol might not work. 2.This protocol is non-responsive in the case of link failure.
3.As the network size increases, the complexity of the storage also increases so overhead increases in that case 10 4.Also bandwidth consumption is high because of the routing paths which are not used 10.
2. TOPOLOGY BASED ROUTING PROTOCOL: There isunique address assignment to all the terminals in this protocol. This protocolcan be further classified into three parts: Figure 10:Topology Based Routing Protocol Classification a. Proactive Routing Protocol: Also known as Table driven protocol, Shortest path algorithms forms thebasis of these protocols. Whenever, there is change in the network, all theparticipating terminals updates their routing tables. DSDV (DestinationSequenced Distance-Vector) is widely used which is a distance vector routing protocol.In this protocol, each record in the routing table consists of a sequencenumber, the sequence number is even if the links are present otherwise they areodd if link is inactive 14.
The DSDV mechanism is as follows: i. UPDATE TECHNIQUE: Each terminal transfersthe updates in regular time instances which consists of their sequences numberand the respective updates of their routing tables. When two consecutive routesto a final point are received from two corresponding neighbour terminals thenit selects the one which has higher sequence number, however in case if thesequence numbers are exactly same then the decision is based on the hop count.Thus, it provides loop free routes 14. ii. TWO-WAY MECHANISM: In this mechanismwhole dump that is full routing table can be transferred to the neighborterminal. It is optimal in case when the network update is more continual andwhen there are less distortions in the network. Next hop will be assigned asthe first terminal going forward towards the final position of hops thus theexact number of the terminals available between the source and the destinationterminal 14.
Figure 11: DSDVRouting 14b. Reactive Routing Protocol: This is also known as on-demand routing protocol inwhich the routing path is selected whenever it is required hence only usedrouting paths are taken into the consideration. This type of protocols is bestsuited to the dynamic network where there is restricted pattern of theavailable routes 10. It can be further classified into 3 categories: i. AODV (AD HOC ON-DEMAND DISTANCE VECTOR ROUTING): In AODV the network is constant till the time a properassociation is required.
The source terminal transmits a appeal messagewhenever it needs a particular path. When the final location collects theappeal then it retransmit the reply message via a short-term route to the sourceterminal. The source terminal then starts the interconnection utilizing thepath which has minimum number of hops, thus the entries which are not used aredeleted after certain interval 14. Every path request has a certain sequencenumber assigned which are different from other respective paths. Thus, it helpsin bypassing repeated path requests. Figure 12: AODVRouting 14 ii.
DSR (DYNAMIC SOURCEROUTING): It is also anon-demand reactive routing protocol in which the source terminal controls thewhole path for every routing procedure 15. This protocol follows a 2-phasemechanism as follows: i. Route Discovery Phase: Whenever there is requirement for the route ittransmits the route appeal and the terminals which collects the packetsretransmit them consequently. ii. Route Maintenance Phase: If there are presence of errors in the transmittedmessages then there will be the deletion of the particular path from the routecache maintained and thus another route to the destination is used.With the use of DSR redundancy can be maintained aswhenever the main route crashes, the alternative route comes into the picturewithout calling the route delivery procedure 15.
For every route request,there is a route reply and It has a RREQ format which has an initiator id,initiator sequence, Target ID and Partial route. Figure 13: RREQFormat Figure 14: Thequery/reply phase in the route discovery procedure 15 iii. TORA (TEMPORALLY ORDERED ROUTINGALGORITHM): TORA is another on-demand routing protocol which makesuse of multi-hop routes. This protocol is not based on shortest path algorithmand therefore, the routing architecture does not constitute distance 15. Itcreates a directed acyclic graph(DAG) which contains the various terminalsbetween the source and the destination and the source node is the main route.
It has a 3-phase mechanism: i. Route Creation: Formation of DAG ii. Route Maintenance: It comes into picture in the case of link failure.
iii. Route Erase: To erase the invalid routes. c. HYBRID ROUTING PROTOCOL: This type of topology based protocol carriesfeatures of both proactive and reactive protocols, thus the main goal is toreduce the proactive routing protocol overhead and minimize the latency of theroute discovery procedure 16.
It divides the network to multiple areas knownas Zones to get the optimal route discovery and maintenance procedures 15. Itis further divided into 2 categories: i. ZRP: In this type of protocol, the terminals in the network are furtherdistributed into special areas known as zones according to many such as powerof broadcasting, moving speed of the nodes and several other factors. ZRP worksas a Proactive protocol for large sized zones and it worked as a reactiveprotocol for small sized zones 16. ii. ZONE-BASED HIERARICHALLINK STATE (ZHLS): It distributes the network into non-intersecting zones and everyterminal in the network consists of a zone ID and a node id by making use ofthe GPS. Thus, they have two topologies at zone and network level 16. Figure 15:Routing Zone of A 16 Figure 16: ZHLSProtocol Topology 16 3.
CLUSTER BASED ROUTING PROTOCOLS : Clusterbased Routing protocol is another category of VANET routing protocol in whichdifferent vehicles forms a cluster depending upon Several characteristics likethe direction and the velocity 10.A virtual Network infrastructure is beingcreated via grouping of several terminals so as to increase the scalability,also this infrastructure is important for scalability of media access,routing protocols and the network infrastructure17.There are two maintechniques for this protocol namely COIN(Clustering for Open inter vehicularcommunication network ) and LORA_CBF 10.a. COIN: In Coin a structurehead is selected based on the dynamics of the vehicles as well as the drivingcalculations rather than the relative mobility. It also carries the revolvingnature of the distance in between the vehicles, and Thus it can be concludedthat COIN produces much more stable architectures and overall lower overhead 17.b. LORA_CBF: In this protocol, each terminal can be the cluster head, gateway or therespective group member.
Gateway can be described as a node connected tomultiple clusters. If the final location is not there then the source terminalwill send the LREQ Packet i.e. the location request packet. This part is sameas that of the AOD but the main difference lies in the LREQ and LREP packetsare dispensed only by the cluster heads and the gateways 17.
Figure 17:Vehicles form multiple clusters in cluster-based routing 17 PROS CONS 1. The scalability is good in a huge group of networks 2. Overhead is less 1. Higher latency in large dynamic networks. 4. BROADCAST BASED ROUTING: As the name indicates,this type of routing method broadcast the packets in the network. There is aspecified broadcast domain and the packets are available to all the vehicleswithin the range of the specified domain. It is mainly used in the emergencysituations such as blockage of roads, sharing weather conditions, in case ofroad accidents and for conveying announcements and advertisements 17.
Floodingis the most acceptable way to carry out a broadcast service in which eachterminal re-transmits message to all of its corresponding neighbors besides theone from which it has received the message concerned 17.Several broadcastbased routing protocols are there such as DVCAST(Distributed Vehicularbroadcast protocol),Position aware reliable broadcasting protocol(POCA) andDensity Aware reliable broadcasting protocol (DECA ) 10.a. BROADCOMM PROTOCOL: For highway environment, broad-communication emergency protocol has beendeveloped in which the architecture of highway is distributed into virtualcells which show movement according to the vehicular movement 18.
Furthermore,the terminals are divided into two levels in which first consists of all theterminals in a respective cell and the second level contains the cellreflectors which are in the proximity to the center of the cell 17. Figure 18:Broadcast routing 17 PROS CONS 1. It is a reliable transmission protocol. 2.Overall overhead is low due to the broadcasting phenomenon 1.
Duplicate packets can be reached to the terminal. 2. Bandwidth requirement is more in this case. 5. GEOCAST ROUTING: Multicast packet forwarding forms the basis of these protocols. A singlesource can send packets to a cluster of nodes which act as a destination.
ZOR(Zoneof Relevance) :- It is defined as a particular geographical area which consistsof a group of nodes to which all the packets are transferred from a particularstarting point18.Whenever the Final destination terminal belongs to adifferent ZOR then communication is done via Zone of forwarding (ZOF),thus allthe vehicles which falls into the ZOF will transmit the data packet to the alternate ZOR’S 10.IVG(Inter-Vehicles Geo-cast protocol) is the most renowned geo-cast protocol whosemain function is to transmit the announcement to the all the vehicles in aparticular risk prone area on delay time algorithm in a highway architecture 17. Figure 19:Geo-cast routing 17 PROS CONS 1.
Overall network congestion is reduced. 2.Overhead is also reduced. 3.Reliable in case of complex network topology.
1. Packet broadcast delay will be there in case of network disconnection 10 II. CONCLUSION AND FUTURE WORK The confluence ofInformation and communication technology, computing and Tele-communication aswell as rise in the vehicular industry are encouraging the optimal utilizationof VANET technologies. In the past years, Several VANETS projects are deployedand several standards have been made to improvise the inter-vehicular orvehicle-to-infrastructure communications 11. A main area where research isgoing on includes VANET security, QOS and to enhance the various broadcastingtechniques.
The different protocols with high priority are still ininvestigation phase when focussing on the security measures 11. Also, Future work will focus on thedevelopment of prevalent applications and context aware driver applicationsystems where cooperative driving techniques can be used for controlling thetraffic 18. Also, research is ongoing on emergency based Protocol to preventthe road blockages and road accidents in case of restricted areas. III. REFERENCES 1. B.Ayyappan et al.
, “Vehicular Ad HocNetworks (VANET): Architectures, Methodologies And Design Issues” 2016 SecondInternational Conference on Science Technology Engineering and Management(ICONSTEM). 2. Wenshuang Liang et al., “Vehicular AdHoc Networks: Architectures, Research Issues, Methodologies, Challenges, andTrends”,2014 InternationalJournal of Distributed Sensor Networks.3. Maria Azees et al., “Comprehensive survey on security services invehicular ad-hoc networks”, IET Intell.
Transp. Syst., 2016, Vol. 10, Iss. 6,pp.
379–388.4. Draft guide for Wireless Accessin Vehicular Environment (WAVE) Architecture’,http://ieeexplore.ieee.org/servlet/opac?punumber-6320593, 2012, pp.
1–74,accessed September 2012.5. Ghosh, M., Varghese, A., Kherani, A.A.
, et al.: ‘Distributed misbehaviordetection in VANETs’. IEEE Wireless Communication and Networking Conf., WCNC2009, Budapest, Hungary, April 2009.6. Fan Li and Yu Wang, “Routing in Vehicular Ad Hoc Networks: ASurvey”, IEEE Vehicular Technology Magazine, June 2007. 7.
S. Abdel Hamid et al., “Routing for Wireless Multi-Hop Networks”,Springer Briefs in Computer Science, DOI: 10.1007/978-1-4614-6357-3_2, TheAuthor(s) 2013.8. Lee MJ et al., “A new taxonomy of routing algorithmsfor wireless mobile ad hoc networks: the component approach”, 2006, IEEECommunications Magazine 44 (11):116–123.
doi:10.1109/MCOM.2006.248174.9. Mauve M, Widmer A, Hartenstein H (2001) A survey on position-based routing in mobile ad hoc networks.
IEEE Network15 (6):30–39. doi:10.1109/65.967595.
10. Proceedings of 2014RAECS UIET Panjab University Chandigarh, 06–08 March, 2014 VANET Routing Protocols:Issues and Challenges UIET, Panjab University Chandigarh, India11. Vehicular ad hocnetworks (VANETS): status, results,and challenges Sherali Zeadally · Ray Hunt ·Yuh-Shyan Chen ·Angela Irwin · Aamir Hassan© Springer Science+Business Media,LLC 201012. Sunder Aditya Rao1Manohara et al.
, “GPSR-L:Greedy Perimeter Stateless Routing with Lifetime for VANETS”, Manipal Instituteof Technology, Manipal, IndiaIRSEEM-ESIGELEC, Technopole du Madrillet, 76800Saint Etienne du Rouvray – France13. M. Bakhouya et al., “PerformanceEvaluation of DREAM Protocol for inter-vehicle Communication”, GSEM/SeTLaboratory, UTBM90010 Belfort.14. Jie Wu, “Analysis ofTopology Based Routing Protocols for Vehicular Ad-Hoc Network (VANET)”,International Journal of Computer Applications (0975 – 8887) Volume *– No., 2014Proceedings of the 35th Hawaii International Conference on System Sciences.15.
Marwa Altayeb1 et al., “Survey of Vehicular Adhoc Networks Routing Protocols”, International Journal of Innovation andApplied Studies and ISSN 2028-9324 Vol. 3 No. 3 July 2013, pp. 829-846© 2013Innovative Space of Scientific ResearchJournalshttp://www.
issr-journals.org/ijias.16. Kanishka Raheja etal., “A Survey on Different Hybrid Routing Protocols of MANET”, BRCM-CET(Bahal), India18, / (IJCSIT) International Journal of Computer Science andInformation Technologies, Vol. 5 (4), 2014, 5512-5516.
17. Fan Li and Yu Wang, “Routingin Vehicular Ad HocNetworks: A Survey”, University of North Carolina at Charlotte,IEEE, 2007.18. M.
Bakhouya et al., “PerformanceEvaluation of DREAM Protocol for Inter-Vehicle Communication”, GSEM/SeTLaboratory, UTBM90010 Belfort.