MSC SEMINAR - PERVASIVE AND ARTIFICIAL INTELLIGENCE RESEARCH GROUP, DEPARTMENT OF INFORMATICS, UNIVERSITY OF FRIBOURG. JUNE 20111

MANET routing protocols based on swarmintelligence

Iliya Enchev Pervasive and Artificial Intelligence Research GroupDepartment of Informatics

University of FribourgEmail: iliya.enchev@unifr.ch

Abstract—A mobile ad-hoc network (MANET) is formed bya group of mobile nodes which communicate over wirelessconnection. The nature of this kind of networks makes themsuitable for deployment in places where network infrastructureis hard to build and maintain. They are flexible, adaptive andrequire few resources but in the same time they are challenging infinding paths that support optimal communication between theircomponent nodes. In order to fulfil this task, suitable routingprotocols are required that are robust, reliable, efficient andat the same time as simple as possible. There exist a numberof swarm intelligence based protocols that try to meet thesecriteria. They are based on the behaviour of animals that formswarms. Two popular group of such protocols are bee- and ant-inspired protocols, which take their principles from ant and beecolonies. In this work the ant-inspired protocols - ARA, SARA,ANSI, AntHocNet, HOPNET and the bee-inspired protocol -BeeAdHoc are regarded and their main features, advantagesand disadvantages are compared between each other as well asto some well established non swarm intelligence protocols, likeAODV. Some results are presented at the end of the paper.

I. INTRODUCTION

Swarm intelligence is defined as the collective behaviourof decentralized, self-organized groups. They are made up ofsimple agents that interact with the environment (so calledstigmergy) and between each other. The agents follow simplerules and possess themselves limited capabilities. They don’tfollow centralized orders for each individual and interactlocally and randomly but together, from a global point ofview, their behaviour emerges as ”intelligent”. Examples forsuch behaviour are searching for food by ants, or searching fornectar by bees. The nature of swarms largely resembles mobilead-hoc networks (MANETs) and that is why ideas from swarmanimals like ants and bees are used for creating suitable routingprotocols for MANETs.

The basic idea behind ant-based routing algorithm is takenfrom the food searching strategy of real ants. They startsearching food from their nest and walk towards the food,sampling different routes. When an ant reaches an intersectionit has to make a decision which way to take next. Alsowhile walking (to the food source and back), ants leavepheromone, a chemical substance, which marks the routethey took. Other ants can smell the pheromone. They candistinguish its concentration as well, which gives a hint tothem for the usage of the route and influences their choice.With time the concentration of pheromone decreases due todiffusion. This property is important for knowing which route

is becoming less occupied, probably due to some deterioration.Fig. 1 shows a scenario in which the best route between twochoices is chosen by the ants after a while.

Bee-inspired algorithms are mainly based on the foragingprinciple of honey bees. Two main types of bees are utilizedfor doing routing in MANET - scouts and foragers. Scoutsdiscover new nodes from their source node to their destinationnode. When a scout reaches its destination, it starts a backwardjourney to its source. When returned to the source, a scoutrecruits the foragers for its route by using the metaphor ofdance [1].

Fig. 1. All ants take the shortest path after an initial searching time. [2]

A. Ant-inspired routing protocols

The first protocol taken into account in this work is Ant-Colony-Based Routing Algorithm (ARA)[2]. It is a highlyadaptive, scalable efficient on-demand (reactive) MANETrouting protocol.

The next algorithm considered in this work is the SimpleAnt Routing Algorithm (SARA) proposed by F. Correia andT. Vazao [3] which is a kind of evolution of the one above- ARA. It offers low overhead facilitated through all threerouting phases - discovery, maintenance and recovery (whichwill be explained later in this work). This is done by meansof three complementary mechanisms - Controlled NeighbourBroadcast (CNB), maintaining active sessions paths and deepsearch procedure that restricts the number of nodes searched.

An unicast protocol for hybrid ad hoc networks - ANSI (Adhoc Networking with Swarm Intelligence) [4] considers theexistence of higher-capability mobile or stationary devices ina network. It is responsive to fluctuating topology and utilizesthe common swarm intelligence routing strategies.

Another proposal for ant-based protocol using hybrid rout-ing is the AntHocNet [5]. It has reactive and proactive com-ponents.

Final ant-based solution considered here is the HOPNET[6], which is again a hybrid protocol. It is based on antcolony optimization (ACO) and zone routing framework forbroadcasting. HOPNET is highly scalable for large networks.

B. Bee-inspired routing protocols

The bee-inspired protocol BeeAdHoc [1] focuses on energyefficiency. It is a reactive source routing algorithm whichstrives to achieve performance similar to established MANETprotocols - DSR, AODV and DSDV but on the cost ofsignificantly less energy.

II. COMPARISON CRITERIA

A. Types of Networks

There are three distinctive types of network that are takeninto account in this work: proactive, reactive, hybrid. Inproactive protocols nodes in the network maintain routinginformation to all other nodes in the network by exchangingperiodically routing information. Nodes with reactive proto-cols delay the route acquisition until there is a demand for aroute. Hybrid protocols use a combination of both proactiveand reactive strategies to gather routes to the destinationsin a network. There can be different level of proactive andreactive routing involved, e.g. a node can collect proactivelyinformation for favourite destination nodes or nodes from theown area and use reactive routing for other nodes.

ARA and SARA are on-demand routing protocols or inother words reactive. BeeAdHoc is reactive is as well.

ANSI uses hybrid routing with both proactive and reac-tive components. The pure mobile nodes in ANSI use onlyreactive routing and choose routes deterministically, whilemore capable (immobile) nodes, part of network infrastructureuse a combination of both proactive and reactive routing andperform stochastic (random) routing when multiple paths areavailable.

AntHocNet is reactive in the route discovery phase and incase of route failure. For the route maintenance phase it actsproactively.

The HOPNET algorithm [6] comprises two strategies - thelocal proactive route discovery within a node’s neighbourhoodand reactive communication between the neighbourhoods. Soit can be derived it is a hybrid protocol. There are two typesof routing tables maintained by HOPNET - Intrazone RoutingTable (IntraRT) and Interzone Routing Table (InterRT). TheIntraRT is proactively maintained so that a node has quickaccess to the paths within its zone. This is done by periodicallysending out forward ants (FANTS) to sample the path withinthe own zone and determine topology changes (nodes movingaway or entering the zone, link failures, etc.), then when the

FANT reaches its destination, a corresponding backwards antis sent back along the discovered path. The other table -InterRT stores the paths to nodes beyond its zone. The tableis updated on demand as route outside one’s own zone isrequired. The peripheral nodes of the zone are used to findroutes between zones.

B. Topology

The ARA algorithm supports dynamic topology with multi-hop paths between nodes. Its optimization method is based onindividual ants and local information from them. No routinginformation in tables has to be transmitted to neighbours orthe whole network.

The SARA topology is again dynamic. When it is formedonly the shortest routes (with the minimum hop count) fromall the broadcasted routes are stored by the network nodes. Thetopologies supported by ANSI and AntHoc can be constantlychanging as well. In the following sections the mechanismsupporting the changing topology will be explained into moredetail (e.g. updates on routing information).

The HOPNET network is divided into zones which arenodes’ local neighbourhoods. The size of the zone is deter-mined by the number of hops and not locally by the radiuslength from a node. Therefore, a routing zone consists of thenodes and all other nodes within the specified radius length.A node may be within multiple overlapping zones and zonescould vary in size. The nodes can be categorized as interiorand boundary (or peripheral) nodes. The distance between theboundary nodes and the central node is the specified radius.All other nodes less than the radius are interior nodes.

In Fig. 2, if the radius of the zone is 2 then for node S,nodes A, D, F, G are boundary nodes, and nodes B, E, C areinterior nodes. All other nodes are exterior nodes (outside thezone). In order to construct a zone, a node, and determiningborder nodes, a node needs to know its local neighbours. Thisis achieved by a detection process based on replies to hellomessages transmitted by each node.

Fig. 2. HOPNET zones [6]

BeeAdHoc is inspired the foraging principle of a honeybee colony [1]. Its Bee Agent Model consists of four types ofagents: packers, scouts, foragers, and swarms.

The packers function like the food-storer bees. They alwaysreside inside the node, receive and store the data packets thatcome from the transport layer. Their main job is to find aforager for their data packet and they die once they hand overto the foragers.

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The scouts discover new routes from their launching node totheir destination node. A scout is broadcasted to all neighbournodes. Once a scout reaches the destination, it finds back itsroute to the source.

Foragers are the main workers in the BeeAdHoc algorithm.They receive the data packets from packers and then transportthem to their destination. Each forager has a special type:delay or lifetime. The delay foragers collect delay informationfrom the network, while the lifetime foragers collect remainingbattery capacity of the nodes they visit. The first type tries toroute packets along a path with minimum delay, while thesecond type selects such a path so that the life time of thenetwork is increased. When a forager reaches its destinationit remains there until it can be piggybacked to the source.This brings the optimization of less control packets, thus savesenergy in the network.

The swarms have a role when nodes do not need explicitacknowledgements for the received data packets. When thedifference between incoming foragers from a certain node iand the outgoing foragers to the same node i reaches a certainthreshold value at a node j, then the node j launches a swarmof foragers to the node i. When the swarm arrives at the nodei then the foragers are extracted from the payload part andthey are stored like they would have arrived at the node in anormal fashion.

C. Phases

In this section the three routing phases - discovery, mainte-nance and recovery of the regarded protocols will be presentedwith their more specific features. First is the ,Route Discoveryphase, followed by the Route Maintenance phase, then theRoute Recovery phase.

1) Route Discovery Phase: In this phase new routes aresearched and established.

In the case of ARA [2], the creation of new routes requiresthe use of forward ant (FANT) and backward ant (BANT).A FANT agent establishes the pheromone track to the sourcenode, while a BANT establishes the pheromone track to thedestination node. The FANT is a small packet baring uniquesequence number. A forward ant is broadcasted by the sourcenode s and is relayed by the neighbour nodes(Fig. 3). A nodethat receives a FANT for the first time creates a record inits routing table, consisting of destination address, next hop,pheromone value. The pheromone value is computed basedon the number of hops the FANT needed to reach the node.Then the node relays the FANT to its neighbours. DuplicateFANTs are identified through the unique sequence numberand source address and are destroyed by the nodes. Whenthe FANT reaches the destination node d, its information isextracted and the FANT itself is destroyed. Subsequently dcreates a BANT and sends it the source s (Fig. 4). The BANThas the same task as the FANT, i.e. establishing a track to s.When the source node receives the BANT from the destinationnode, the path is established and data packets can be sent.

By AntHocNet [5] a source node s checks its routinginformation if it has up-to-date route with the destination nodeand if not it sends a reactive forward ant similar to the ARA

Fig. 3. Route discovery phase. A forward ant (F) is send from the sender (S)toward the destination node (D). The forward ant is relayed by other nodes,which initialize their routing table and the pheromone values. [2]

Fig. 4. Route discovery phase. The backward ant (B) has the same task asthe forward ant. It is send by the destination node toward the source node.[2]

above, to look for paths to d. These ants gather informationconcerning the quality of the path they followed and thenwhen they reach the destination they become backward antswhich trace back their path and update routing tables. In therouting tables there is information on the goodness of thepaths to each destination through each next hop. This is thepheromone. With its help multiple paths between s and d canbe indicated, and packets can be routed as datagrams. Thechoice of the path happens stochastically - in each node thepackets select the next hop with a probability proportionalto the pheromone values. AntHocNet provides better waysto select which FANTS to be propagated and which to bediscarded than ARA. It considers not only the number of hopsbut as well the time to reach a hop. By discarding some worseFANTS overhead is limited.

By the route discovery phase SARA brings innovativeapproach compared to for example AntHocNet. Usually, aswas seen above, the source node starts the route discoveryprocess by sending a forward ANT, which is replicated byall network nodes until it reaches the destination node orneighbourhood. Upon receiving the first FANT, the destinationsends a BANT through the shortest known path(s). If thepacket arrives at the source then path is established and dataflow may start. This approach requires two-way routing aswith AntHocNet and creates significant amount of controlinformation in case of long paths. The FANT is also replicated,creating flooding, which deteriorates performance. To copewith this SARA introduces a more efficient mechanism todisseminate FANTs: Controlled Neighbour Broadcast (CNB).Here each node broadcasts the FANT to all of its neighbours,who process it, but only one of them broadcasts the FANTagain to its own neighbourhood. The selection of the noderesponsible for ”re-broadcasting” the FANT is done in aprobabilistic manner.

HOPNET makes a separation in the route discovery phase

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within a neighbourhood of nodes and between neighbourhoods(zones) [6]. Within a zone the discovery is proactive andbetween zones it is reactive.

The route discovery phase within a zone is accomplishedwith the help of the intrazone routing table - IntraRT, whichwas mentioned earlier, and internal forward ants, which aredifferent than the external forward ants. The internal forwardants are sent periodically to all neighbours to maintain theIntraRT. In the IntraRT there is information on the neighbournodes in a zone - pheromone, visited times, hops, SeqNo.Pheromone is for the pheromone concentration of a link,visited times gives the number of times a link has been visitedby the ants, hops is the number of hops between a nodes andanother node in its zone.

The format of the ants contains Source, Destination, Se-quenceNo, Type, Hops and Path. The sequence number whichis present also in the IntraRT table is for distinguishing packetsand avoid duplications. The Source field stores the sourceaddress. The Destination stores the destination address, whichis left blank for internal forward ants and stores the destinationnode’s address only for external ants. The Type field indicatesone of five possible ant types: internal forward ant, externalforward ant, backward ant, notification ant, error ant. The Hopsfield indicates the number of hops a forward ant can move.This field is assigned only for internal forward ants and is leftblank for external. Path field represents the sequence of nodesbetween source and destination [6].

When a source node s has to send data to a destinationnode d, s first checks the columns of its IntraRT table ifthe destination lies in its zone. If this is the case then routediscovery is done. If d is within the zone of s there will alwaysbe a route between the nodes, which is proactively maintainedwith periodically send ants.

In the case when the source node s fails to find its des-tination within its zone, the InterRT table is used, which isresponsible for the between zones route discovery phase. TheInterRT contains paths to destinations with expiration timeand sequence number (to avoid duplications). When a routeoutside a source’s zone is searched it is checked in the tableif this route has not been already discovered recently (beforethe expiration time), if this is the case, the source node sendsits packet along the path that is pointed in the InterRT table.Otherwise external forward ants have to be sent. It is forwardedto peripheral nodes (which are known in the IntraRT table),and then possibly to other zones’ peripheral nodes until thedestination’s node is reached. Then the external forward anttransforms into a backward ant and functions similarly to thebackward ants of the other ant-based protocols seen here.When the backward ant reaches its source, the path found byit is added to the InterRT table and communication betweenthe source and destination may take place.

ANSI has similar to HOPNET local proactive managementand non-local reactive management. Its phases are not clearlydescribed by its authors so its phases description will beskipped.

In the case of BeeAdHoc, route discovery is done by thescout bees [1]. They are similar to FANTs and BANTs. As wasexplained above, a scout is broadcasted to all neighbour nodes

with an expanding time to live timer (TTL), which controlsthe number of time the scout could be re-broadcasted. Whenit reaches the destination, it starts to trace back its route to thesource (much like a BANT). One difference with ant-basedalgorithms though is that when a scout is at the source node,it recruits the foragers for its route by using the metaphor ofdance, just like scout bees in nature.

2) Route Maintenance: By the route maintenance inmost cases the ant-inspired protocols use the metaphor ofpheromone. The most used links experience the highestpheromone levels, while the unused ones have the lowestlevels. This happens with two complementary mechanismsof increasing and decreasing the pheromone intensity. Thefirst happens with every packet that crosses a link, reaches itsdestination and then produces a backward link. The decreasinghappens with time when no traffic happens through nodes.

By this phase ARA utilizes fully the pheromone tracksestablished by FANTs and BANTs and updated by transporteddata packets. The protocol doesn’t create special extra packetsfor route maintenance, the only improvement to the basicprinciple it adds is the duplicate packets elimination basedon sequence numbering and source address.

The routing maintenance phase of HOPNET [6], as de-scribed by its authors, corresponds rather to the route recovery(repair) phase as defined below in this work. For the routemaintenance (as considered in this current section) HOPNETmakes use of pheromone concentration like the other protocolspresented. The pheromone values are updated as packetstraverse from source to current node, which influences antscoming subsequently from the source. Because of this, themechanism is described with the term source update algorithm[6].

AntHocNet - When the paths are established and a datasession is running, s starts to send proactive forward ants tod. These ants follow the pheromone values as well and monitorthe used paths. They also have a small probability of beingbroadcasted, so they can find new paths.

The improvement that SARA brings in the route mainte-nance phase is in the case of asymmetric traffic (like UDP).Such traffic does not generate backward packets, which pre-vents maintaining correct pheromone levels. While AntHocNetsolves this problem by generating additional control traffic,SARA uses special FANT messages calls super FANTs. Thesuper FANT is generated at an end node (source or destination)where asymmetric traffic is detected. It has a pheromonereinforce equivalent capability of n standard FANTs. Thissuper FANT is generated with lower frequency, than thearriving packet rate, which reduces overhead.

Route maintenance by BeeAdHoc is executed partly byforager bees and partly by swarm bees, as far as theirdefinitions are given. The foragers collect state informationabout the network depending on their type (delay foragers andlifetime foragers) and also bring optimizations (less controloverhead). The swarms help in the case where no or scarceacknowledgement are sent by destination nodes.

3) Route Recovery: The route recovery is a process that isinitiated when a broken link between two nodes is detected.The broken link may happen for several reasons, like a node

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being turned off, failure in radio coverage or congestionthat causes a higher number of collisions, etc. In MANET,these kinds of situations may occur frequently and thus, theroute recovery procedure must be quickly executed with lowoverhead.

ARA detects route failure if there is a missing acknowl-edgement [2]. If a node gets a route error message for a link,it deactivates the link by setting the pheromone value to 0.Then an alternative link is searched in the routing table. If thenodes finds such, it sends the packet vie this path. Otherwisethe node informs its neighbours to check if they can relay thepackets. Either they can or the backtracking continues to thesource node. If the packet can not reach the destination, a newroute discovery phase has to be initiated.

To recover the route, AntHocNet and SARA will try to findalternative routes in the neighbourhood of the broken link.However, AntHocNet will attempt to reach the destinationnode with a standard FANT, but with a limited number ofallowed broadcast transmissions, so that the ant is confinedin the area of the destination. SARA also uses broadcasttransmission with RFANT messages, but will attempt to findan alternative path that can reach the other side of the brokenlink instead of reach the destination node. If several nodesgo down simultaneously it might not be possible to find analternative route, using this local repair procedure. If the localrepair procedure fails to succeed, an error message is sent tothe source node and the route discovery procedure is initiated.

As noted in the prior section, HOPNET’s route recovery,as considered here, is described in the section ”Route main-tenance” [6] by its authors. If there is an invalid route withina zone it is periodically repaired proactively, because of theIntraRT table which is proactively maintained. If the route isbetween zones, the upstream node of the broken link will try alocal repair procedure, aiming to find an alternative path to thedestination, while buffering the incoming packets. If the nodeis successful in finding alternative path, it sends a notificationant to the source that lets it know of the route change. Allnodes on the path of the notification change their inter routingtables as well to remove the invalid nodes. If this can nothappen, an error ant is sent to the source, which initiates anew route discovery procedure.

With its mechanisms HOPNET provides evolution of themethods adopted in ARA and AntHocNet presented before.

By BeeAdHoc the recovery is possibly done by the foragers,but there is not enough information provided by its authors [1].

III. EXPERIMENTAL RESULTS AND COMPARISON TO WELLKNOWN ALGORITHMS LIKE AODV

Most of the algorithms considered in this work are com-pared by their authors to classical routing solutions like AODV,DSR, etc. In this section some results are shown.

A. Metrics for comparison

In this work the most common metrics are used to measurethe performance of the presented MANET routing protocols -packet delivery ratio, number of packets and end to end delay.

1) Packet Delivery: Packet delivery ratio (PDR) is the ratioof successfully delivered data packets to the total data packetssent from the source to the destination.

2) Overhead: Overhead is calculated by the ratio betweenthe amount of information needed to carry control traffic overthe total amount of traffic that has been sent.

3) End to end delay: This is the difference between thetime once a packet is received by the application layer of adestination node and the time when a packet is originated atthe application layer of a source node.

B. ARA

The ARA protocol is compared to the Ad-hoc On-demandDistance Vector (AODV), Destination-Sequenced DistanceVector (DSDV) and Dynamic Source Routing (DSR) [2].OnFig. 5 the fraction of successfully delivered packets is shownas function of pause time between which nodes move. It can beseen that in the case of higher dynamics only DSR outperformsARA, but ARA’s performance is still satisfying and in generalits performance is better than AODV and DSDV.

Fig. 5. Successfully delivered packets as a function of pause time [2].

C. SARA

The Fig. 6 presents the overhead results of SARA comparedto the non-swarm-intelligence protocol AODV, and two otherprotocols that are also analysed in this work - ARA andAntHocNet. The graphic shows that SARA presents the bestperformance, concerning overhead, which is almost indepen-dent of the nodes velocity. According to the authors of SARA[3], this fact is caused by the use of the Constant Bit Rate(CBR) and by the optimizations that were realized in theroute maintenance. The use of a flooding mechanism and thecontinuous generation of control traffic for the active routes areresponsible for the worst performance of AntHocNet, AODVand ARA. The use of a source-routing mechanism, where allthe entire path information is carried by the FANT messagesis also responsible for the worst performance exhibited byAntHocNet. These relative results are shared by UDP andFTP/TCP traffic Fig. 7. Nevertheless, smaller overhead valuesare experienced when FTP traffic is used, because the moresignificant amount of data traffic is generated.

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Fig. 6. CBR Traffic [3]

Fig. 7. FTP Traffic [3]

D. ANSI

ANSI is compared to AODV similarly to the other protocolsabove. AODV is suited for hybrid ad hoc networks whichmakes it good for comparison with ANSI as well.

The results presented by the authors of ANSI [4] showthe performance of ANSI vs. AODV over a hybrid networkusing UDP flows. It can be concluded that ANSI consistentlyoutperforms AODV in terms of packet delivery and delay (Fig.8).

The reason why ANSI performs better than AODV de-livering more packets with better metrics such as delay andnumber of route errors is because ANSI manages the localnetwork information better than AODV does, and performscongestion-aware routing.

E. AntHocNet

A comparison between AntHocNet and AODV shows (Fig.9) that AntHocNet can outperform AODV in terms of delivery

Fig. 8. Packet delivery and delay. [4]

ratio and average delay. AODV has only a little advantagewhen all packets are taken into account for the delay mea-surement, but if the 99-th percentile of the delay is taken itcan be seen that the decrease in performance of AODV ismainly due to a small number of packets with a very highdelay.

Fig. 9. Packet delivery and delay. [5]

F. HOPNET

On Fig. 10 the delivery ratio of HOPNET and AODV isshown. It can be seen that with fewer nodes HOPNET is worsethan AODV. When there is a link failure HOPNET tries to passthe packets to other alternative proximate nodes and if thereare less nodes in general this proves to be inefficient, but itis seen also that with increased number of nodes HOPNETperforms better.

Fig. 10. Delivery ratio. [6]

The control overhead of HOPNET Fig. 11 is generallyhigher than AODV, because AODV is purely reactive protocoland HOPNET is proactive within a zone. The proactive packetscreate the extra overhead.

Fig. 12 shows a comparison between the end to end delayof HOPNET and AODV. It is clearly seen that HOPNET

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Fig. 11. Routing overhead. [6]

produces better results. This is due to the division in zonesby HOPNET and the intrazone routing tables as well as theinerzone routing tables. With them the paths for transmissionare readily accessible.

Fig. 12. End to end delay. [6]

G. BeeAdHoc

Three comparison measurements are shown for BeeAdHocdepending on varying packet send rates. On Fig. 13 the packetdelivery ratio is shown. Although all algorithms perform wellwith increased loads, BeeAdHoc shows the smallest decreasein success rates and keeps the second highest rates in general.

Fig. 13. Packet delivery ratio. [1]

Fig. 14, the energy expenditure is shown instead of over-head, because energy efficiency is one of the main motivationsfor BeeAdHoc and it can be clearly seen that BeeAdHoc hasthe lowest energy expenditure.

Fig. 14. Energy expenditure. [1]

Fig. 15, the delay is shown. The decreased delay withincreased load is due to the fact that route discovery timeis shared between more packets and thus it becomes lesssignificant. BeeAdHoc shows lowest delays.

Fig. 15. Packet delay. [1]

IV. CONCLUSION

A number of state of the art swarm-intelligence inspiredMANET protocols are considered in this work and put topartial comparison. It is shown that by using ideas taken fromthe simple behaviour of ants and bees optimization and inno-vations in routing protocols can be done, that help outperformthe standard MANET routing protocols like AODV, DSDV,DSR. Depending on application needs the presented protocolsprovide also customizing and tuning capabilities that can makethem suitable for a wide range of MANET applications.

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