Research Article Ensuring Reliable Communication in...

Research ArticleEnsuring Reliable Communication in Disaster RecoveryOperations with Reliable Routing Technique

Varun G Menon1 Joe Prathap Pathrose2 and Jogi Priya3

1Department of Computer Science Engineering Sathyabama University Tamil Nadu 600119 India2Department of Information Technology RMD Engineering College Chennai 601206 India3Department of Computer Science Engineering Karpagam University Coimbatore 641021 India

Correspondence should be addressed to Varun G Menon varunmenonscmsgrouporg

Received 1 October 2015 Revised 31 December 2015 Accepted 14 January 2016

Academic Editor Claudio Agostino Ardagna

Copyright copy 2016 Varun G Menon et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

The purpose of this research paper is to ensure reliable and continuous communication between the rescue officers and otherpeople during disaster recovery and reconstruction operations Most of the communication infrastructure gets damaged duringthe disaster and proper communication cannot be established in the area which leads to longer delays in emergency operations andincreased damage to life and property Various methods proposed to enable communication between the people using wireless adhoc networks do not guarantee reliable delivery of data with fast moving devicesThis paper presents a Reliable Routing Technique(RRT) that ensures reliable data delivery at the destination device even when the people with the mobile devices are moving inthe network We make use of the broadcasting property of the wireless network and create a priority list of probable forwardingcandidates at each device With this technique RRT ensures that if a forwarder device is unable to forward the data packet due tomovement ofmobile devices the next priority candidate forwards the data packet to the destination device thus ensuring reliabilityof data delivery in the network Simulation results show that RRT achieves significant performance improvement with better datadelivery in ad hoc networks

1 Introduction

The world has witnessed a number of natural disasters overthese years causing huge losses to human and animal lifeinfrastructure and almost everything in the region Thesenatural hazards like earthquakes floods and hurricanes havealways struck in different places at unpredictable timesleading to the increase in damage of life and propertyAlthough science has made vast progress in many areasscientists are still unable to accurately predict the time andplace of these disasters and the extent of damage that mightoccur The Indian Tsunami in 2004 [1 2] is one among manythat have made us realize the extent of damage a naturaldisaster can cause in unpredictable situations So the majorfocus has always been on minimizing the damage that mightbe caused by a natural disaster and to stay ready for disasterrecovery and reconstruction operations [3]

Disaster recovery and reconstruction operations havealways been a challenging task for the government localauthorities and the people The primary aim of the firemenpolice officers local guards and other rescue officers arrivingjust after the event is to look for the survivors and tohelp the injured These first responders arriving at the siteimmediately after the disaster have to deal with a numberof issues and challenges In some cases it is necessary forthem to prevent the damage from spreading to other areasThey have to search for the survivors within the damagedbuildings and also have to make sure that the medicalassistance reaches the survivors in minimum time Oncethe survivors are found and medical assistance is giventhe next major task is to rebuild the basic infrastructure tostart the reconstruction works A major issue during theserecovery and reconstruction operations is that most of theinfrastructure used for transportation communication andso forth would have been completely or partially damaged

Hindawi Publishing CorporationMobile Information SystemsVolume 2016 Article ID 9141329 10 pageshttpdxdoiorg10115520169141329

2 Mobile Information Systems

with the disaster and it becomes quite difficult to handleand coordinate the entire process without the help of thisinfrastructure

One of the most important requirements in the disasterrecovery and emergency response situations is to establishreliable and continuous communication between the officersmedical team and other rescue workers [4] Effective com-munication is very important in coordinating the rescueworkand also in reconstruction works after the disaster In orderto carry out efficient and quick recovery the rescue workerspolice officers and everyone involved may have to move at afast pace to different locationswithin the area tominimize thedamage and to find out more survivors of the disaster But inmost of the situations the communication infrastructure getsdamaged and proper communication cannot be establishedin the area which leads to longer delays in emergencyoperations and increased damage to life and property [5]

A number of solutions have been proposed over theseyears to establish communication in disaster managementservices [6ndash8]The use of ad hoc networks [9ndash11] is one of thebest techniques used in establishing communication duringdisaster relief operations Ad hoc wireless networks are acollection ofmobile devices that can be configured to work asa single network and can be deployed in these areas withoutthe help of any infrastructure or centralized control Anynumber of mobile devices like mobile phones and personalcomputers can be attached to the ad hoc network Everymobile device is free to join or leave the network at anypoint of time Every device in the network acts as the routeras well as the host When a mobile device sends a datapacket into the network the device in its transmission rangereceives the data packet and then forwards the packet tothe next device in its transmission range and so on till itreaches the destination Although a number of techniqueshave been proposed for the transmission of the data fromthe source to the destination due to constant movementof mobile devices none of the methods guarantee deliveryof the information at the destination [12 13] Also mostof the methods do not support continuous communicationbetween the mobile devices [14] It is very important forall the people at the place of the disaster including thesurvivors and rescue workers to communicate with eachother while moving from one place to the other at a fastpace for safety tominimize the damageThus reliable deliveryof information and continuous communication become twoimportant factors in efficient working of disaster recoveryoperations even with fast moving people using devices likemobile phones laptops iPads and so forth

This paper provides a new technique called ReliableRouting Technique (RRT) that utilizes opportunistic routingto guarantee the delivery of information at the destinationdevice We use the term data packet for the informationpassed in the wireless network When a device sends a datapacket into the network all the devices in its transmissionrange receive the data packet We create a priority list ofthese mobile devices The mobile device that is nearest tothe destination is given the highest priority and is alwaysselected to forward the data packet to the next device Ifthat particular mobile device moves away during this time

the next prioritymobile device forwards the data packet in thenetwork Thus communication is maintained as long as onemobile device receives the transmission and thus the deliveryof data packet at the destination is guaranteed Simulationresults show that RRT achieves high data delivery even whenthe mobile devices are moving rapidly from one place to theother

The first section of this paper discusses the variousresearch work that has already been carried out in thearea of reliable communication in disaster managementThe next section analyses the reasons for the failure ofcommunication systems during the disaster recovery processand also analyses the importance of telecommunicationsin disaster recovery and reconstruction processes based onthe data collected from the questionnaires and personalinterviews The next section describes the proposed ReliableRouting Technique for reliable and continuous delivery ofinformation during disaster recovery and reconstructionprocess Next section explains the implementation detailswith results and discussionsWe conclude the paper in the lastsection with discussion to future works and enhancements

2 Related Work

A number of research papers have been published high-lighting the effects of natural disasters in various regionsaround the world Most of these papers have highlighted theimportance of being prepared for emergency and disasterrecovery works Reference [15] has reviewed the effect of theearthquake that hit Kobe Japan in 1995The paper highlightsthe changes that have taken place over time in the region foreffective disastermanagement Another book [16] reviews themajor natural disasters that have hit various regions of theworld in 2011 and discusses the effects of natural disasterson the country and its people Reference [17] highlights theproblems and issues that can occur if people are not wellprepared for disaster management Reference [18] explainsthe various steps that are required for every region for disasterpreparation and management with reference to the island ofHawaii The paper [19] describes the various steps that needto be implemented for prevention and efficient recovery fromnatural disasters

The importance of communication during disaster recov-ery process has been a major area of study over these yearswith a number of research papers published highlightingthe need for effective means of communication in disasterrecovery and reconstruction works Reference [4] has given adetailed explanation of the need for telecommunication dur-ing the disaster recovery process The paper also highlightsthe various steps that can be implemented as a preparation tomeet the disaster recovery process Reference [20] proposeda public safety communication system by integrating wirelesslocal area network and the radio Although this was a newapproach in public safety communication the method hadscalability problems and some major issues Reference [10]gave an ad hoc network for disaster relief operations thatwas used for communication and in tracing people insidedamaged buildings Although the method had a numberof additional functions apart from communication reliable

Mobile Information Systems 3

delivery and high performance could not be achieved withmoving mobile devices Reference [21] reviewed the variousmethods that are available for communication in public safetyand disaster management

Reference [22] gave a rapid emergency deploymentmobile communication node that uses several communica-tion technologies to provide multiple communication ser-vices in disaster management situations The system alsosupported live video streaming andmultimedia content shar-ing along with the traditional communication services Theproposed node included a hybrid power source based on bothrenewable and nonrenewable energy generators and batteriesto provide electric autonomy A pneumatic telescopic mastis installed to support communication antennas providingmobility and increased coverage range One or more nodescan be easily and quickly deployed in any location of interestto provide communication services Reference [23] proposeda flexible network architecture that provided a common net-working platform for heterogeneousmultioperator networksfor interoperation in case of emergencies Reference [24]gave excellent techniques using key agreements to enhancethe security of mobile wireless networks Reference [25]discussed the communication services that can be exploitedduring the disaster recovery and reconstruction operations

As the focus was more on deploying the ad hoc networkand its security fewer papers have worked on reliable andcontinuous data delivery between the fast moving mobiledevices The traditional topology based protocols like DSR[26] and DSDV [27] suffer from increased node mobilityThese protocols are much more focused on fixed routesand their performance decreases with dynamic topologyand node mobility This leads to data loss in the networkwhich is unacceptable in emergency situations The idea ofgeographic routing [28] provided a much reliable and betterway of transferring data in ad hoc networks Geographicrouting uses location information or the geographic positionof the node to transfer data from one node to the otherThe location information is transferred as one-hop beaconbetween the nodes GPSR [29] is one of the most populargeographic routing protocols that use greedy forwardingand perimeter routing to transfer data in dynamic wirelessnetworks But even geographic routing suffers from a majordrawback that it is very sensitive to inaccuracies in locationinformation and its performance comes down with highmobility of nodes This gave way to opportunistic routingand opportunistic forwarding [30] The broadcasting natureof wireless networks was exploited with the ExOR [30]opportunistic routing protocol ExOR protocol providedan improved way to utilize the broadcasting property ofthe wireless links to enhance communication at the datalink and network layers of multihop wireless networks thatremained static It is a hybrid routing and MAC protocol forwireless networks that improves the data delivery of unicasttransmissions Here the sender broadcasts a batch of packetsEvery packet has a list of nodes which can forward it Tomaximize the progress of each transmission the forwardingnode would send data packets in the order of their nearnessto the destination node To reduce redundant transmissionsExOR uses a batch map which would store the list of packets

received at each node every forwarding node would onlyforward data that has not been acknowledged by the nodesnearer to the destination in their particular batch mapsExOR provides significant throughput improvement overearlier routing strategies but ExOR cannot support multiplesimultaneous flows and thus limits the practical use of thisprotocol in these fast reconfiguring networks This problemwas addressed by the SOAR [31] protocol SOAR supportssimultaneous flows in multiple paths It also incorporatesadaptive forwarding path selection to leverage path diversityand minimizes duplicate transmissions But one of the majorlimitations with this protocol is that it uses link state styletopology database for routing In order to determine therate of loss of packets we often require periodic network-wide updates and measurement This would be impracticalin wireless networks with highly dynamic nodes In order toavoid this problem some protocols introduced the batchingsystem [32] Butmany applications using this system incurredmuch delay in packet arrival Most of the recent locationbased routing schemes [33] do not entirely address theproblem of additional memory consumption and overheadincurred A community aware opportunistic routing [34] wasproposed towork onmobile nodeswith social characteristicsReference [35] proposed an opportunistic routing scheme tohandle communication voids in fastmoving ad hoc networksReference [36] proposed a parallel routing scheme which isperformed by many nodes simultaneously to maximize theopportunistic gain while controlling the interuser interfer-ence Most of these routing protocols suffered from one ormore disadvantages and were not able to guarantee reliabledata delivery at the destinationThis hasmotivated us to workon this new method of RRT that guarantees reliable deliveryof information between the rescue workers during the timeof disaster and in its recovery and reconstruction phases

3 Analysing the Reasons forthe Failure of Communication Systemsduring the Time of Disaster

Data for the analysis was collected through questionnairesfrom the people affected by 2013 Uttarakhand floods [37] inIndia Personal interviews were carried out with the rescueworkers and other people who took part in the disasterrecovery and reconstruction works The questionnaires andinterviews were focused on two major things (1) the reasonsfor the failure of communication systems during the time ofdisaster and (2) the importance of a reliable communicationnetwork during the disaster

Figure 1 shows the analysis of the data collected throughquestionnaires Out of 419 responses received 321 (7661)people indicated that the primary reason for the failureof telecommunication systems during the disaster is thedestruction of communication infrastructure and networkelements 74 (1766) people indicated the isolation andfailure of supporting elements in communication as themajorreason for the failure 21 (501) people were of the opinionthat the excess network load and network congestion wereresponsible for the failure of communication during the time


Destruction of communication infrastructure and network elementsIsolation and failure of supporting elements in communicationNetwork overload and congestionUnable to answer

Figure 1 Reasons for the failure of communications system datafrom the questionnaires

of the disaster and in the recovery process Figure 2 showsthe analysis of the data collected through personal inter-views Out of 44 rescue workers interviewed 20 (4545)people indicated that the primary reason for the failureof telecommunication systems during the disaster is thedestruction of communication infrastructure and networkelements 16 (3636) people indicated the isolation andfailure of supporting elements in communication as themajorreason for the failure and 8 (1818) people were of theopinion that the excess network load and network congestionwere responsible for the failure of communication during thetime of the disaster and in its recovery process

From the above results we concluded that the failure ofcommunication systems during natural disaster and in recov-ery and reconstruction works occurs mainly due to thesethree reasons with most of the people citing the destructionof physical infrastructure needed for communication as theprimary reason

(i) Destruction of Communication Infrastructure and NetworkElements Natural disaster often destroys the physical com-munication infrastructure and network components like thetransmission towers base stations and so forth Most ofthese telecommunication equipment pieces like transmissiontowers are very much prone to natural disasters due totheir structure and place of deployment Once this physicaltelecommunication infrastructure gets destroyed it becomesvery difficult to have proper means of communication in thedisaster affected areas

(ii) Isolation and Failure of Supporting Elements in Com-munication This is one of the major challenges faced inensuring communication during the time of the disasterand afterwards The infrastructure like electricity supplytransportation systems and so forth that supports commu-nication infrastructures gets damaged during these unpre-dictable eventsThese supporting elements play a vital role in

Destruction of communication infrastructure and network elementsIsolation and failure of supporting elements in communicationNetwork overload and congestion

Figure 2 Reasons for the failure of communications system datafrom the interviews

the telecommunication sector and thus entire communica-tion system is hampered by the destruction of these elements

(iii) Network Overload and Congestion During the time of adisaster most of the people try to communicate with othersand overload the available communication bandwidth

4 Analysing the Importance ofReliable and Continuous Communicationduring the Disaster

Communication networks play a vital role in disaster man-agement services In this section we analyze the impor-tance of reliable and continuous communication in disastermanagement services using the data obtained from thequestionnaires and interviews Figure 3 shows the analysisof the data collected through questionnaires We used LikertScale to mark the responses Out of 419 responses received345 (8233) people indicated that reliable and continuouscommunication was ldquovery importantrdquo during the disasterand in disaster management services 40 (954) peoplecalled it ldquoimportantrdquo while 29 (69) people indicated it asldquomoderately importantrdquoA smallminority 3 (0007) peoplecalled it ldquoof little importancerdquo and 2 (0004) people calledit ldquounimportantrdquo Figure 4 shows the analysis of the datacollected through personal interviews

Out of 44 rescueworkers interviewed 38 (8636) peopleindicated that reliable and continuous communication wasldquovery importantrdquo during the disaster and in disaster man-agement services Four (909) people indicated that reliablecommunication was ldquoimportantrdquo while 2 (45) peopleindicated it as ldquomoderately importantrdquo None of the rescueworkers selected the ldquoof little importancerdquo and ldquounimportantrdquooptions So it is evident that all the rescue workers that tookpart in disaster recovery and reconstruction works regard


Very importantImportantModerately important

Of little importanceUnimportant

Figure 3 Importance of reliable and continuous communicationduring the disaster data from questionnaires



Figure 4 Importance of reliable and continuous communicationduring the disaster data from interviews

reliable communication as a very important factor in disastermanagement

From the analysis it is very evident that reliable and con-tinuous communication between the people rescue workersand everyone at the site was extremely important during thetime of the disaster and also afterwards in disaster recoveryand reconstruction processes So it is necessary to providea technique for reliable and continuous communicationbetween the rescue officers and various people involvedduring the disaster recovery process to ensure minimumdamage to life and property

5 Reliable Routing Technique (RRT)

The working of the Reliable Routing Technique (RRT) isillustrated in Figure 5 The small circles depict the wireless

B998400

D2

E

F

C

XY

Z

P

QD1A

BForwarding area

Mobiledevice

Transmissionrange of S1


S1S2

Figure 5 Data transferred between the wireless nodes using RRT

devices like mobile phones laptops iPads and so forthused by different people in the disaster hit area Let us firstconsider device S1 held by a rescue officer trying to sendinformation to device D1 held by another rescue officerin the wireless network Wireless devices have a uniqueproperty of broadcasting every data piece it receives into thenetwork [38] Wireless devices communicate with each otherby broadcasting every data packet it receives into the networkWe make use of this property in designing our new methodUsing this property of the wireless medium the person usingthe mobile device S1 broadcasts the information intended forthe person with device D1 into the wireless ad hoc network

Position of the destination is obtained using a locationregistration and lookup service used in [29] This servicewould map node addresses to the locations We considertwo situations to implement the working of Reliable RoutingTechnique (RRT) In the first situation we assume that thereare no disruptions and problems in the wireless link andwireless channel and there is no movement of the devices outof the transmission area Mobile devices X Y and Z whichare in device S1rsquos transmission range receive the data packetWe create a priority list of these devices such that the mobiledevice that is nearer to the destination is selected as the devicewhichwould forward the data further towards the destinationdevice We then share the priority list between the neighbor-ing devices So based on the priority list device Y is selectedto forward the data packet or the information towards thedestination device Device Y would first check whether thedestination device is in its transmission range If yes it woulddirectly deliver the data packet to the destination If notdevice Y broadcasts the data packet towards the destinationDevices X and Zwhich are in the transmission range of Y alsoreceive a copy of the same data packet and thus they realizethat the data packet has been already forwarded by anotherbest forwarder mobile device So they drop the data packetMeanwhile the packet is received by devices P and Q Basedon the priority list P has the maximum progress towards thedestination Mobile device P would initially check whetherthe destination device D1 is in its transmission range or notAs it finds destination D1 in its transmission range it deliversthe data packet to the destination

In the second scenario we assume that the rescue officerswith mobile devices are moving to different places Let us


consider device S2 held by a rescue officer trying to sendinformation to device D2 held by another rescue officer inthe wireless network Device S2 broadcasts the data whichis received by A B and C Based on the method we wouldselect device B as the first priority candidate to forward thepacket But device B moves out of the transmission rangebecause of themovement of the rescue officer handling deviceB Thus device B is unable to receive the data packet Wehave set a timer (T) for every device Once the timer expiresand devices A and C do not receive the copy of the samedata packet (devices A and C have already obtained one copyof the data packet from S2) based on the priority list setthe second priority device device A forwards the packets tothe destination device Similarly device F receives the datapacket and delivers it to the destination device So as long asthere is one device in the priority list the delivery of the dataat the destination device and continuous communication isguaranteed

51 Developing Priority List of Forwarding Candidates Weconstruct a priority list of forwarding nodes in the networkso that if one node is unable to receive or forward the packetthe next priority node can do it thus ensuring continuouscommunication even with highly mobile nodes We have setthe priority list in such a way that only nodes located in theforwarding area would be given priorities and the chance toforward the packet

Algorithm for constructing the forwarder priority list isas follows

initializationset the destination node as NDset the Forwarder Priority List as FPL and initialize itsvalue to zeroset the Neighbor Node List as NNLset the transmission range as TRset the distance from the current node to the destina-tion node ND as CNDIST

(1) begin(2) if destination node is in the list of neighbors

then(3) set destination node as the next hop node(4) return(5) end if(6) for jlarr 0 to length(NNL) do(7) NNL[j]distlarr dist(NNL[j] ND)(8) end for(9) NNLsort()(10) next hoplarr NNL[0](11) for jlarr 1 to length(NNL) do(12) if dist(NNL ND) ge length of FPL or CNDIST(13) then(14) break(15) else if dist(NNL[j] NNL[0]) lt TR2

(16) then(17) FPLadd(NNL[j]) and set the priority for each

node starting from 1(18) end if(19) end for

The source node broadcasts data packet intended forthe destination into the network The proposed algorithm(steps (1)ndash(5)) initially checks whether the destination nodeis in the list of neighbors of the node receiving the datapacket If the destination node is found the data packet isdelivered Next we consider all the neighboring nodes of theinitial node and calculate the distance (steps (6)ndash(9)) of eachneighboring node with the destination and sort the list Thenwe allocate priorities to each node with the node with theshortest distance to the destination getting the first priorityfollowed by the next and so on The first priority node wouldbe selected as the best forwarder node by the neighboringnode for that particular data transmission For each node weconstantly check (steps (10)ndash(17)) whether the distance to thenext hop node exceeds half of the transmission range of thatnode and whether it moves way from the transmission rangeIf it exceeds the distance wewould remove it from our list andupdate the Forwarder Priority List (FPL)

6 Results and Discussion

We study the performance and properties of Reliable RoutingTechnique through simulations in Network Simulator-2 [39]We had developed different types of topologies with differentnumber of nodes for evaluating the performance UsingNetwork Simulator-2 we create an environment similar to adisaster hit areawithmanywireless devicesThemovement ofthe rescue officers is simulated by moving the mobile devicesrandomly in the network Initially we carry out simulationwith 100 nodes with a uniformly distributed network topol-ogy The packet size is set at 256 bytes and the transmissionrange is 250m The nodes are distributed over a 1000m times800m rectangular region The two-ray ground propagationmodel is used for the simulation Mobility is introduced inthe network with the Random Way Point mobility modelThe speed of the nodes is then varied from a minimum of1ms to various maximum limits in each topology setup toanalyse the performance of the protocol in fast changingMANETs with highly mobile nodes Constant Bit Rate Trafficis generated between the nodes The simulation time is set at1000 seconds We compare and evaluate the performance ofRRT with AODV and GPSR protocol based on three metricsThese three metrics are very crucial in deciding the reliabilityand performance of a routing protocol especially with highlydynamic nodes

(i) PacketDelivery Ratio (PDR) It is one of themost importantmetrics in deciding the performance of a routing protocol ina network It is defined as the ratio of data packets received atthe destination(s) to the number of data packets sent by thesource(s)


Table 1 Performance analysis of RRT

Speed of themobile devices(ms)

Packetdelivery ratio

Average delay(s)

Length ofpath (hops)

0 09992 0003 212 09991 0003 214 09991 0006 216 09987 001 218 09985 001 2110 09985 0011 22

(ii) Average End-to-End Delay It is the average delay inreceiving an acknowledgement for a delivered data packet

(iii) Length of Every Path It is the average end-to-end (nodeto node) path length for successful packet delivery

(iv) Data Forwarding Times for EachHop It is average numberof times a packet is forwarded from network layer to deliverdata over each hop

(v) Data Forwarding Times for Each Packet It is the averagenumber of times a packet is forwarded from the network layerto deliver the data

Initially we varied the speed of the mobile devices from 0to 10ms and the corresponding values for the performancemetrics were noted Table 1 shows the values of the threeperformance metrics with varying mobility of the nodes Asthe speed of wireless nodes increases there is a small declinein the Packet Delivery Fraction and a small increase in theaverage delay experienced by the data packet But as the speedvariation is limited to 10ms much variation in performancemetrics cannot be observed This is because the proposedopportunistic routing scheme works equally well in normaland dynamic scenarios As a result even the number of hopstaken by the data packet to reach the destination remains thesame with a value of 21 Further when we increase the speedof nodes to 50ms more variation is found which is shownin Figures 6ndash10

From Figure 6 we can see that using Reliable RoutingTechnique the Packet Delivery Fraction is very close to 1 Asthe Packet Delivery Fraction is very close to the optimal valuewe can interpret that the packet loss that occurred isminimalThis is because RRT guarantees delivery at the destination aslong as there is one node in the Forwarder Priority List

Figures 6 7 8 9 and 10 show the comparison of theperformance of RRT with GPSR and AODV protocols FromFigure 6 it is evident that the Packet Delivery Fraction (PDF)of RRT is much better compared to the other two protocolsThis implies that the number of packets received at thedestination is much larger for the RRT protocol The PDFvalue for RRT protocol is very near to 1 which means thatalmost all the data packets sent are delivered at the receiver Asthe mobility of nodes increases the PDF of GPSR and AODVprotocol comes down considerably but RRT maintains ahigh delivery ratio Figure 7 shows that the average delay

086

088

09

092

094

096

098

1

102

5 10 15 20 25 30 35 40

Pack

et d

eliv

ery

ratio

Speed (ms)

RRTGPSR

AODV

Figure 6 Packet delivery ratio versus speed

00005

0010015

0020025

0030035

0040045

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age e

nd-to

-end

del

ay (s

)

Figure 7 Average delay (source to destination)

experienced by the data packets using RRT protocol is muchless compared to the other two Also as the mobility of thenodes increases the performance of the GPSR and AODVcomes down Similarly from Figure 8 we can see that RRTtakes smaller number of hops to deliver the data packetcompared to the other two protocols These results showthat RRT would ensure reliable delivery of data packets withminimum delay in fast changing ad hoc networks

Figure 9 shows the average packet forwarding timesper hop for the three protocols We can see that the aver-age time taken by RRT to forward a data packet is lesscompared to GPSR and AODV protocols This shows thatdelay experienced by RRT protocol at each hop is very lesscompared to the other two protocols leading to RRTrsquos highefficiency Figure 10 shows the average packet forwardingtimes per packet for the three protocols From the figurewe can see that RRT takes less time to forward the datapacket compared to the other two protocols This shows thatthe delay experienced by each packet using RRT is very lesscompared to the other two protocols in the network Also wecan see that as the speed of nodes increases the performanceof GPSR andAODV comes down but RRTmaintains a steady


0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et le

ngth

(hop

s)

Figure 8 Length of every path

0

02

04

06

08

1

12

14

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et fo

rwar

ding

tim

es p

er h

op

Figure 9 Data forwarding times for each hop

performance This shows that the RRT protocol maintains avery good performance even with highly mobile and randomnodes in the network From the simulation results it is evidentthat RRT achieves better performance compared to the othertwo protocols and ensures high rate of data delivery even infast changing and reconfiguringmobile ad hoc networks withhighly mobile nodes

7 Conclusions

In this paper we initially analyzed the importance of reliableand continuous communication in disaster recovery andreconstruction works The data obtained from the question-naires and personal interviews confirmed that reliable andcontinuous communication was very important in disas-ter management services We also discussed a number ofmethods given by various researchers for communicationin disaster environments Most of these methods could notguarantee reliable data delivery at the destination deviceUsing the broadcast property of the wireless medium theproposed Reliable Routing Technique was used for datadelivery between two mobile devices in highly mobile ad hoc

0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age f

orw

ardi

ng ti

mes

per

pac

ket

Figure 10 Data forwarding times for each packet

networks Results from the simulations and comparisonswiththe other popular data transfer methods confirmed that ourmethod gave very high performance and guaranteed reliabledata delivery at the destination device and also ensuredcontinuous communication between the devices

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] R Shaw ldquoIndian ocean tsunami and aftermath need forenvironment-disaster synergy in the reconstruction processrdquoDisaster Prevention and Management vol 15 no 1 pp 5ndash202006

[2] M P Escaleras and C A Register ldquoMitigating natural disastersthrough collective action the effectiveness of Tsunami earlywarningsrdquo Southern Economic Journal vol 74 no 4 pp 1017ndash1034 2008

[3] K Lorincz D J Malan T R F Fulford-Jones et al ldquoSensor net-works for emergency response challenges and opportunitiesrdquoIEEE Pervasive Computing vol 3 no 4 pp 16ndash23 2005

[4] A M Townsend and M L Moss Telecommunications Infras-tructure in Disasters Preparing Cities for Crisis Communi-cations Center for Catastrophe Preparedness and ResponseRobert F Wagner Graduate School of Public Service New YorkUniversity New York NY USA 2005

[5] R E Krock ldquoLack of emergency recovery planning is a disasterwaiting to happenrdquo IEEE Communications Magazine vol 49no 1 pp 48ndash51 2011

[6] Y-M Lee B-L Ku and D-S Ahn ldquoA satellite core networksystem for emergency management and disaster recoveryrdquo inProceedings of the International Conference on Information andCommunication Technology Convergence (ICTC rsquo10) pp 549ndash552 Jeju Republic of Korea November 2010

[7] K Mase N Azuma and H Okada ldquoDevelopment of an emer-gency communication system for evacuees of sheltersrdquo in Pro-ceedings of the IEEE InternationalWireless Communications andNetworking Conference (WCNC rsquo10) pp 1ndash6 Sydney AustraliaApril 2010


[8] K Mase ldquoHow to deliver your message fromto a disaster areardquoIEEE Communications Magazine vol 49 no 1 pp 52ndash57 2011

[9] I Chlamtac M Conti and J J-N Liu ldquoMobile ad hocnetworking imperatives and challengesrdquo Ad Hoc Networks vol1 no 1 pp 13ndash64 2003

[10] N Pogkas G E Karastergios C P Antonopoulos S KoubiasandG Papadopoulos ldquoArchitecture design and implementationof an ad-hoc network for disaster relief operationsrdquo IEEETransactions on Industrial Informatics vol 3 no 1 pp 63ndash722007

[11] C-C Shen C Srisathapornphat and C Jaikaeo ldquoAn adaptivemanagement architecture for ad hoc networksrdquo IEEE Commu-nications Magazine vol 41 no 2 pp 108ndash115 2003

[12] E M Royer and C-K Toh ldquoA review of current routingprotocols for ad hoc mobile wireless networksrdquo IEEE PersonalCommunications vol 6 no 2 pp 46ndash55 1999

[13] V G Menon and P M Joe Prathap ldquoPerformance analysisof geographic routing protocols in highly Mobile Ad Hocnetworkrdquo Journal of Theoretical and Applied Information Tech-nology vol 54 no 1 pp 127ndash133 2013

[14] V G Menon and P M Joe Prathap ldquoPerformance of variousrouting protocols inmobile ad hoc networks-a surveyrdquoResearchJournal of Applied Sciences Engineering and Technology vol 6no 22 pp 4181ndash4185 2013

[15] R Shaw andKGoda ldquoFromdisaster to sustainable civil societythe Kobe experiencerdquo Disasters vol 28 no 1 pp 16ndash40 2004

[16] E Ferris and D Petz The Year that Shook the Rich A Reviewof Natural Disasters in 2011 Brookings-Bern Project on InternalDisplacement London UK 2012

[17] P Rautela and R K Pande ldquoImplications of ignoring the olddisaster management plans lessons learnt from the Amparavtragedy of 23 September 2004 in the Nainital district ofUttaranchal (India)rdquoDisaster Prevention and Management vol14 no 3 pp 388ndash394 2005

[18] R Prizzia ldquoCoordinating disaster prevention and managementin Hawaiirdquo Disaster Prevention and Management vol 15 no 2pp 275ndash285 2006

[19] M Oral A Yenel E Oral N Aydin andN Aydin ldquoEarthquakeexperience and preparedness in Turkeyrdquo Disaster Preventionand Management vol 24 no 1 pp 21ndash37 2015

[20] A K Salkintzis ldquoEvolving public safety communication sys-tems by integrating WLAN and TETRA networksrdquo IEEECommunications Magazine vol 44 no 1 pp 38ndash46 2006

[21] G Baldini S Karanasios D Allen and F Vergari ldquoSurvey ofwireless communication technologies for public safetyrdquo IEEECommunications Surveys amp Tutorials vol 16 no 2 pp 619ndash6412014

[22] I G Askoxylakis A Makrogiannakis A Miaoudakis et alldquoA rapid emergency deployment mobile communication noderdquoin Proceedings of the IEEE 19th International Workshop onComputer Aided Modeling and Design of Communication Linksand Networks (CAMAD rsquo14) pp 290ndash294 Athens GreeceDecember 2014

[23] A G Fragkiadakis I G Askoxylakis E Z Tragos and CV Verikoukis ldquoUbiquitous robust communications for emer-gency response using multi-operator heterogeneous networksrdquoEURASIP Journal onWireless Communications and Networkingvol 2011 article 13 2011

[24] I G Askoxylakis T Tryfonas J May V Siris and A TraganitisldquoA family of key agreement mechanisms for mission criticalcommunications for secure mobile ad hoc and wireless mesh

internetworkingrdquo EURASIP Journal on Wireless Communica-tions and Networking vol 2011 Article ID 807684 2011

[25] A I Miaoudakis N E Petroulakis D Kastanis and I GAskoxylakis ldquoCommunications in emergency and crisis sit-uationsrdquo in Distributed Ambient and Pervasive InteractionsSecond International Conference DAPI 2014 Held as Part of HCIInterational 2014 Heraklion Crete Greece June 22ndash27 2014Proceedings vol 8530 of Lecture Notes in Computer Science pp555ndash565 Springer Berlin Germany 2014

[26] D B Johnson D A Maltz and J Broch ldquoDSR the dynamicsource routing protocol formultihop wireless ad hoc networksrdquoin Ad Hoc Networking pp 139ndash172 Addison-Wesley BostonMass USA 2001

[27] C E Perkins and P Bhagwat ldquoHighly dynamic destination-sequenced distance-vector routing (DSDV) for mobile com-putersrdquo in Proceedings of the Conference on CommunicationsArchitectures Protocols and Applications (SIGCOMM rsquo94) pp234ndash244 ACM London UK 1994

[28] F Cadger K Curran J Santos and S Moffett ldquoA surveyof geographical routing in wireless Ad-Hoc networksrdquo IEEECommunications Surveys amp Tutorials vol 15 no 2 pp 621ndash6532013

[29] B Karp and H T Kung ldquoGPSR greedy perimeter statelessrouting for wireless networksrdquo in Proceedings of the 6th ACMAnnual International Conference on Mobile Computing andNetworking (MobiCom rsquo00) pp 243ndash254 Boston Mass USAAugust 2000

[30] S Biswas and R Morris ldquoExOR opportunistic multi-hoprouting for wireless networksrdquo in Proceedings of the Confer-ence on Applications Technologies Architectures and Protocolsfor Computer Communications (SIGCOMM rsquo05) pp 133ndash144ACM Philadelphia Pa USA August 2005

[31] E Rozner J Seshadri Y Mehta and L Qiu ldquoSOAR simpleopportunistic adaptive routing protocol for wireless meshnetworksrdquo IEEE Transactions on Mobile Computing vol 8 no12 pp 1622ndash1635 2009

[32] A Balasubramanian R Mahajan A Venkataramani B NLevine and J Zahorjan ldquoInteractiveWiFi connectivity formov-ing vehiclesrdquo in Proceedings of the ACM SIGCOMM Conferenceon Data Communication (SIGCOMM rsquo08) pp 427ndash438 ACMSeattle Wash USA August 2008

[33] K Zeng Z Yang and W Lou ldquoLocation-aided opportunisticforwarding in multirate and multihop wireless networksrdquo IEEETransactions on Vehicular Technology vol 58 no 6 pp 3032ndash3040 2009

[34] M Xiao J Wu and L Huang ldquoCommunity-aware opportunis-tic routing in mobile social networksrdquo IEEE Transactions onComputers vol 63 no 7 pp 1682ndash1695 2014

[35] V G Menon and P M Joe Prathap ldquoOpportunistic routingwith virtual coordinates to handle communication voids inmobile ad hoc networksrdquo in Advances in Signal Processing andIntelligent Recognition Systems vol 425 ofAdvances in IntelligentSystems and Computing pp 323ndash334 Springer International2016

[36] W-Y Shin S-Y Chung and Y H Lee ldquoParallel opportunisticrouting inwireless networksrdquo IEEE Transactions on InformationTheory vol 59 no 10 pp 6290ndash6300 2013

[37] G Kabra and A Ramesh ldquoAn empirical investigation of theenablers in humanitarian supply chain management in Indiaa case studyrdquo Journal of Advances in Management Research vol12 no 1 pp 30ndash42 2015


[38] M Nikolov and Z J Haas ldquoTowards optimal broadcast inwireless networksrdquo IEEE Transactions on Mobile Computingvol 14 no 7 pp 1530ndash1544 2015

[39] ldquoThe Network Simulator -ns-2rdquo 2013 httpwwwisiedunsn-amns

Submit your manuscripts athttpwwwhindawicom

Computer Games Technology

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Distributed Sensor Networks


Advances in

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Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014


ReconfigurableComputing

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014


Applied Computational Intelligence and Soft Computing

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with the disaster and it becomes quite difficult to handleand coordinate the entire process without the help of thisinfrastructure

One of the most important requirements in the disasterrecovery and emergency response situations is to establishreliable and continuous communication between the officersmedical team and other rescue workers [4] Effective com-munication is very important in coordinating the rescueworkand also in reconstruction works after the disaster In orderto carry out efficient and quick recovery the rescue workerspolice officers and everyone involved may have to move at afast pace to different locationswithin the area tominimize thedamage and to find out more survivors of the disaster But inmost of the situations the communication infrastructure getsdamaged and proper communication cannot be establishedin the area which leads to longer delays in emergencyoperations and increased damage to life and property [5]

A number of solutions have been proposed over theseyears to establish communication in disaster managementservices [6ndash8]The use of ad hoc networks [9ndash11] is one of thebest techniques used in establishing communication duringdisaster relief operations Ad hoc wireless networks are acollection ofmobile devices that can be configured to work asa single network and can be deployed in these areas withoutthe help of any infrastructure or centralized control Anynumber of mobile devices like mobile phones and personalcomputers can be attached to the ad hoc network Everymobile device is free to join or leave the network at anypoint of time Every device in the network acts as the routeras well as the host When a mobile device sends a datapacket into the network the device in its transmission rangereceives the data packet and then forwards the packet tothe next device in its transmission range and so on till itreaches the destination Although a number of techniqueshave been proposed for the transmission of the data fromthe source to the destination due to constant movementof mobile devices none of the methods guarantee deliveryof the information at the destination [12 13] Also mostof the methods do not support continuous communicationbetween the mobile devices [14] It is very important forall the people at the place of the disaster including thesurvivors and rescue workers to communicate with eachother while moving from one place to the other at a fastpace for safety tominimize the damageThus reliable deliveryof information and continuous communication become twoimportant factors in efficient working of disaster recoveryoperations even with fast moving people using devices likemobile phones laptops iPads and so forth

This paper provides a new technique called ReliableRouting Technique (RRT) that utilizes opportunistic routingto guarantee the delivery of information at the destinationdevice We use the term data packet for the informationpassed in the wireless network When a device sends a datapacket into the network all the devices in its transmissionrange receive the data packet We create a priority list ofthese mobile devices The mobile device that is nearest tothe destination is given the highest priority and is alwaysselected to forward the data packet to the next device Ifthat particular mobile device moves away during this time

the next prioritymobile device forwards the data packet in thenetwork Thus communication is maintained as long as onemobile device receives the transmission and thus the deliveryof data packet at the destination is guaranteed Simulationresults show that RRT achieves high data delivery even whenthe mobile devices are moving rapidly from one place to theother

The first section of this paper discusses the variousresearch work that has already been carried out in thearea of reliable communication in disaster managementThe next section analyses the reasons for the failure ofcommunication systems during the disaster recovery processand also analyses the importance of telecommunicationsin disaster recovery and reconstruction processes based onthe data collected from the questionnaires and personalinterviews The next section describes the proposed ReliableRouting Technique for reliable and continuous delivery ofinformation during disaster recovery and reconstructionprocess Next section explains the implementation detailswith results and discussionsWe conclude the paper in the lastsection with discussion to future works and enhancements

2 Related Work

A number of research papers have been published high-lighting the effects of natural disasters in various regionsaround the world Most of these papers have highlighted theimportance of being prepared for emergency and disasterrecovery works Reference [15] has reviewed the effect of theearthquake that hit Kobe Japan in 1995The paper highlightsthe changes that have taken place over time in the region foreffective disastermanagement Another book [16] reviews themajor natural disasters that have hit various regions of theworld in 2011 and discusses the effects of natural disasterson the country and its people Reference [17] highlights theproblems and issues that can occur if people are not wellprepared for disaster management Reference [18] explainsthe various steps that are required for every region for disasterpreparation and management with reference to the island ofHawaii The paper [19] describes the various steps that needto be implemented for prevention and efficient recovery fromnatural disasters

The importance of communication during disaster recov-ery process has been a major area of study over these yearswith a number of research papers published highlightingthe need for effective means of communication in disasterrecovery and reconstruction works Reference [4] has given adetailed explanation of the need for telecommunication dur-ing the disaster recovery process The paper also highlightsthe various steps that can be implemented as a preparation tomeet the disaster recovery process Reference [20] proposeda public safety communication system by integrating wirelesslocal area network and the radio Although this was a newapproach in public safety communication the method hadscalability problems and some major issues Reference [10]gave an ad hoc network for disaster relief operations thatwas used for communication and in tracing people insidedamaged buildings Although the method had a numberof additional functions apart from communication reliable


































B998400

D2

E

F

C

XY

Z

P

QD1A

BForwarding area

Mobiledevice



S1S2






















Average delay(s)


0 09992 0003 212 09991 0003 214 09991 0006 216 09987 001 218 09985 001 2110 09985 0011 22








086

088

09

092

094

096

098

1

102

5 10 15 20 25 30 35 40

Pack

et d

eliv

ery

ratio

Speed (ms)

RRTGPSR

AODV


00005

0010015

0020025

0030035

0040045

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age e

nd-to

-end

del

ay (s

)





0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et le

ngth

(hop

s)


0

02

04

06

08

1

12

14

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et fo

rwar

ding

tim

es p

er h

op



7 Conclusions


0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age f

orw

ardi

ng ti

mes

per

pac

ket





References


















































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in




































B998400

D2

E

F

C

XY

Z

P

QD1A

BForwarding area

Mobiledevice



S1S2






















Average delay(s)


0 09992 0003 212 09991 0003 214 09991 0006 216 09987 001 218 09985 001 2110 09985 0011 22








086

088

09

092

094

096

098

1

102

5 10 15 20 25 30 35 40

Pack

et d

eliv

ery

ratio

Speed (ms)

RRTGPSR

AODV


00005

0010015

0020025

0030035

0040045

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age e

nd-to

-end

del

ay (s

)





0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et le

ngth

(hop

s)


0

02

04

06

08

1

12

14

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et fo

rwar

ding

tim

es p

er h

op



7 Conclusions


0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age f

orw

ardi

ng ti

mes

per

pac

ket





References


















































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in




















Average delay(s)


0 09992 0003 212 09991 0003 214 09991 0006 216 09987 001 218 09985 001 2110 09985 0011 22








086

088

09

092

094

096

098

1

102

5 10 15 20 25 30 35 40

Pack

et d

eliv

ery

ratio

Speed (ms)

RRTGPSR

AODV


00005

0010015

0020025

0030035

0040045

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age e

nd-to

-end

del

ay (s

)





0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et le

ngth

(hop

s)


0

02

04

06

08

1

12

14

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et fo

rwar

ding

tim

es p

er h

op



7 Conclusions


0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age f

orw

ardi

ng ti

mes

per

pac

ket





References


















































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in




0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et le

ngth

(hop

s)


0

02

04

06

08

1

12

14

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Pack

et fo

rwar

ding

tim

es p

er h

op



7 Conclusions


0

05

1

15

2

25

3

5 10 15 20 25 30 35 40Speed (ms)

RRTGPSR

AODV

Aver

age f

orw

ardi

ng ti

mes

per

pac

ket





References


















































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in













































Advances in

FuzzySystems


Volume 2014












Journal of

Journal of





Advances in

Multimedia


Biomedical Imaging



Advances in


RoboticsJournal of










Advances in



Research Article Ensuring Reliable Communication in...

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