• The KIPS Transactions:PartC
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• v.14C no.1 s.111
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• pp.87-94
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• 2007

In mobile ad hoc networks the most popular on demand routing protocols are the Dynamic Source Routing (DSR) protocol and the Ad hoc On demand Distance Vector (AODV) routing protocol. These and other representative standard routing protocols are designed to find and maintain only a single path. Whenever there is a link break on the active route, source node has to invoke a route discovery process from the beginning and it causes a lot of overhead. Multipath routing protocols, which can alleviate these problems by establishing multiple alternative paths between a source and a destination, are widely studied. In this paper we propose a node disjoint multipath discovery technique based on AODV local route discovery. This technique can find and build completely separated node disjoint multi paths from a source to a destination as many as possible. It will make routing more robust and stable.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.240-243
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• 2007

Geographic routing has been considered as an efficient simple, and scalable routing protocol for wireless sensor networks since it exploits pure location information instead of global topology information to route data packets. Geographic routing requires the sources nodes to be aware of the location of the sinks. In this paper, we propose a scheme named Sink Location Service for geographic routing in wireless Sensor Networks, in which the source nodes can get and update the location of sinks with low overhead. In this scheme, a source and a sink send data announcement and query messages along two paths respectively by geographic routing. The node located on the crossing point of the two paths informs the source about the location of the sink. Then the source can send data packet to the sink by geographic routing. How to guarantee that these two paths have at least one crossing point in any irregular profile of sensor network is the challenge of this paper.

• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.135-139
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• 2014

Opportunistic routing was originally introduced in various multihop network environments to reduce the number of hops in such a way that, among the relays that decode the transmitted packet for the current hop, the one that is closest to the destination becomes the transmitter for the next hop. Unlike the conventional opportunistic routing case where there is a single active S-D pair, for an ad hoc network in the presence of fading, we investigate the performance of parallel opportunistic multihop routing that is simultaneously performed by many source-destination (S-D) pairs to maximize the opportunistic gain, thereby enabling us to obtain a logarithmic gain. We first analyze a cut-set upper bound on the throughput scaling law of the network. Second, computer simulations are performed to verify the performance of the existing opportunistic routing for finite network conditions and to show trends consistent with the analytical predictions in the scaling law. More specifically, we evaluate both power and delay with respect to the number of active S-D pairs and then, numerically show a net improvement in terms of the power-delay trade-off over the conventional multihop routing that does not consider the randomness of fading.

• Journal of KIISE:Information Networking
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• v.31 no.5
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• pp.519-531
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• 2004

Ad-hoc networks are temporary wireless systems composed of mobile nodes without any fixed infrastructure. The life time of each node in the ad-hoc network significantly affects the life time of whole ad-hoc network. A node which drained out its battery may incur the partition of whole network in some network topology The life time of each node depends on the battery capacity of each node. Therefore if all mobile nodes in the network live evenly long, the life time of the network will be longer. In this paper, we propose Power-Aware Dynamic Source Routing (PADSR) which selects the best path to make the life time of the network be longer. In PADSR, when a source node finds a path to the destination node, it selects the best path that makes nodes in the network live evenly long. To find the best path, PADSR considers the consumption of transmission energy and residual battery capacity of nodes upon the path. Consequently the network lives longer if we use PADSR.

• Journal of the Korea Society for Simulation
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• v.13 no.4
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• pp.55-69
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• 2004

In MANET(Mobile Ad-hoc Network), unlike in wired networks, a path configuration should be in advance of data transmission along a routing path. Frequent movement of mobile nodes, however, makes it difficult to maintain the configured path and requires re-configuration of the path very often. It may also leads to serious problems such as deterioration of QoS in mobile ad-hoc networks. In this paper, we proposed a Reactive Routing Keyword (RRK) routing procedure to solve those problems. Firstly, we noticed it is possible in RRK routing to assign multiple routing paths to the destination node. We applied this feature into active networks and SNMP information based routing by storing unique keywords in cache of mobile nodes corresponding to present and candidate routings in a path configuration procedure. It was shown that the deterioration of QoS which may observed in Dynamic Source Routing(DSR) protocol was greatly mitigated by using the proposed routing technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2C
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• pp.188-195
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• 2012

Many systems are developing for the realization of NCW(Network Centric Warfare). UAV(Unmanned Aerial Vehicle) Network is attracting attention in a lot of military applications. In general, UAVs have the potential to create an ad-hoc network and greatly reduce the hops from source to destination. However, UAV networks exhibit unique properties such as high mobility, high data rate, and real time service. The routing protocols are required to design the multi-hop routing protocols that can dynamically adapt to the requirements of UAV network. In this paper we analyse Geographic Routing Protocol is based on geographical distance between source and destination for efficient and reliable transmission. Geographic Routing Protocol is evaluated in video service scenarios with TDMA model in our simulation. The simulation results show that the performance of Geographic Routing Protocol is better than the MANET Routing Protocol in terms of packet received ratio, end to end delay, and routing traffic sent.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.308-316
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• 2015

In this paper, we carried out performance comparison of four routing protocols that had been proposed for mobile ad hoc networks using the NS-3 network simulator. Those four routing protocols consist of two proactive routing protocols, DSDV(destination-sequenced distance vector) and OLSR(optimized link state routing), and two reactive routing protocols, AODV(ad-hoc on-demand distance vector) and DSR(dynamic source routing). Two performance metrics, system throughput and packet delivery ratio, are adopted and performance evaluation was carried out in a square communication area where each communicating mobile node moves independently. Numerical results show that the AODV routing protocol provides the best performance among those four routing protocols.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.8B
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• pp.636-645
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• 2008

Most of routing schemes that protect the source's location from a malicious attacker usually make use of a path of a long length per message for the sake of lengthening the safety period. The biggest problem to such approaches is taking a very long latency in transferring messages to the destination. In this paper we show the problem to find the least-cost single path that is enough to keep the source-location always secure from the attacker, provided that it is used for the delivery of a set of messages given in priori, is NP-complete. Consequently we propose a routing protocol GSLP-w(GPSR-based Source-Location Privacy with crew size co) that is a trade-off between two extreme approaches. The advantage of GSLP-co lies in its enhanced safety period for the source and its lowered delivery latency in messaging. We consider NSP(Normalized Sefety Period) and NDL(Normalized Delivery Latency), measured in terms of the least number of hops to the destination, to achieve tangible interpretation of the results. We ran a simulation to confirm our claim by generating 100 topologies of 50,000 nodes with the average number of neighbors being 8. The results show that GSLP-$\omega$ provides more enhanced NSP compared to other protocols GSLP, an earlier version of GSLP-$\omega$, and PR-SP(Phantom Routing - Single Path), the most notable existing protocol for the source-location privacy, and less NDL than that of GSLP but more than that of PR-SP.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1609-1612
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• 2004

Ad hoc network is a kind of new wireless network paradigm for mobile hosts. Ad Hoc wireless networks consist of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. Mobile hosts rely on each other to keep the network connected. Each host is not only mobile hosts but also router. So how to design a routing protocol is the most important problem. Dynamic source routing is a kind of routing protocol. In this paper we suggest a new automatic route shortening method and an energy-aware routing mechanism based on DSR.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2205-2217
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• 2015

Bio-inspired routing protocol uses a principle of swarm intelligence, which finds the optimal path to the destination in a distributed and autonomous way in dynamic environments, so that it can maximize routing performances, reduce control overhead, and recover a path failure quickly according to the change of network topology. In this paper, we propose a bio-inspired routing protocol for mobile ad hoc networks. The proposed scheme uses a function of overhearing via wireless media in order to obtain the routing information without additional overhead. Through overhearing, the pheromone is diffused around the shortest path between the source and destination. Based on this diffused pheromone, a probabilistic path exploration is executed and the useful alternative routes between the source and destination are collected. Therefore, the proposed routing protocol can ensure the up-to-date routing information while reducing the control overhead. The simulation results show that the proposed scheme outperforms the typical AODV and AntHocNet protocols in terms of routing performances and significantly decreases the routing overhead against the AntHocNet.