• Journal of KIISE:Information Networking
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• v.35 no.4
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• pp.282-291
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• 2008

This paper focuses on message complexity performance analysis of MANET AAPs in reference to link errors generated by the mobile wireless nodes. To obtain the message complexity performance of AAPs in reference to the link error probability ($P_e$), an enhancement was made by proposing the retransmission limit (S) to be computed for error recovery (based on the link error probability), and then for each of the AAPs the control procedures for the retransmission limit have been properly included. The O-notation has been applied in analyzing the upper bound of the number of messages generated by a MANET group of N nodes. Based on a link error probability range of $P_e=0$ to 0.8, the AAPs investigated in this paper are Strong DAD, Weak DAD with proactive routing protocol (WDP), Weak DAD with on-demand routing protocol (WDO), and MANETconf. Based on the simulation results and analysis of the message complexity, for nominal situations, the message complexity of WDP was lowest, closely followed by WDO. The message complexity of MANETconf is higher than that of WDO, and Strong DAD results to be most complex among the four AAPs.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.98-107
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• 2008

In mobile ad hoc networks, packet loss is unavoidable due to MAC contention, link failure or the inherent characteristics of wireless link. Since TCP relies on the timely reception of TCP ACK packets to progress the transmission of the TCP DATA packets, ACK loss obviously affects the performance due to two main problems: (a) Frequent occurrence of spurious retransmissions caused by timeout events and (b) impairment of the fast retransmit mechanism caused by the lack of a sufficient number of duplicate ACK packets. In particular, since most reactive routing protocols force the packets buffered over a path to be discarded while performing a route recovery, the performance degradation becomes more serious due to such ACK loss. In this paper, therefore, TCP with two piggybacking schemes (called TCP-pgy) is proposed in order to resolve the above-mentioned problems over reactive routing protocols. Through extensive simulations using the ns-2 simulator, we prove that our proposed schemes contribute to TCP performance improvements.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.493-498
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• 2011

In this paper, Transmission performance over MANET(Mobile Ad-hoc Networks) under DDoS Intrusions is evaluated. Intrusion counterplan requirement, which have to be used for MANET under DDoS intrusions, is suggested through this evaluation. VoIP simulator based on NS-2 network simulator is used for performance measurement. MOS, network delay, packet loss rate and call connection rate is measured with this simulation. Finally, requirement of intrusion continuing time shorter then 10 seconds is suggested for VoIP service over MANETs under DDoS intrusions.

• Journal of Communications and Networks
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• v.18 no.2
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• pp.238-245
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• 2016

A sequence number checking technique is proposed to improve the performance of TCP connections in mobile ad hoc networks. While a TCP connection is initialized, a routing protocol takes the responsibility for checking the hop count between a source and destination pair. If the hop count is greater than a predefined value, the routing protocol decides to use a proxy node. The responsibility of a proxy node is to check the correctness of data packets and inform the missing packets by sending an acknowledgement from a proxy node to the source node. By doing so, the source node is able to retransmit any missing packet in advance without waiting until an end-to-end acknowledgement is received from the destination. Simulation results show that the proposed mechanism is able to increase throughput up to 55% in static network and decrease routing overhead up to 95%in mobile network.

• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.329-336
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• 2012

For designing broadcast protocols in mobile ad hoc networks (MANETs), one of the important goals is to reduce the rebroadcast packets redundancy while reaching all the nodes in network. In this paper, we propose a probabilistic broadcasting mechanism based on selfishness and additional coverage in MANETs. Our approach dynamically adjusts the rebroadcast probability according to the extra covered area and number of neighbor nodes. By these two factors, mobile hosts can be classified into three groups: normal, low selfishness, and high selfishness groups. The nodes in the normal group forward packets for other nodes with high probability, whereas the nodes in the low selfishness group rebroadcast packets with low probability and the nodes in the high selfishness group do not rebroadcast packets. We compared our approach with simple flooding and the fixed probabilistic approach. The simulation results show that the proposed schemes can significantly reduce the number of retransmissions by up to 40% compared simple flooding and fixed probabilistic scheme without significant reduction in the network reachability and end-to-end packet delay.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2826-2834
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• 2013

In mobile ad hoc networks (MANET), power-saving technology of mobile nodes is divided into transmit power control (TPC), power-saving mode (PSM), and routing. TPC and PSM are operated in physical layer but the routing is managed in network layer, so the design of a joint algorithm is needed to provide better performance. Therefore, in this paper, we propose a joint power-saving and routing algorithm for maximizing the network lifetime while satisfying the end-to-end data rate in ad hoc networks. The proposed algorithm first applies the TPC or PSM to reduce the power consumption of mobile nodes and then performs the routing by considering the decided node lifetime in order to maximize the path lifetime. Simulation results show that the proposed algorithm maximize the lifetime while satisfying the required rate according to the number of mobile nodes and the level of interference.

• International Journal of Computer Science & Network Security
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• v.21 no.7
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• pp.341-349
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• 2021

Many emerging mobile ad-hoc network application communications are group-oriented. Multicast supports group-oriented applications efficiently, particularly in a mobile environment that has a limited bandwidth and limited power. Energy effectiveness along with safety are 2 key problem in MANET design. Within this paper, MANET is presented with a stable, energy-efficient clustering technique. In this proposed work advanced clustering in the networks with ticket ID cluster manager (TID-CMGR) has formed in MANET. The proposed routing scheme makes secure networking the shortest route possible. In this article, we propose a Cluster manager approach based on TICKET-ID to address energy consumption issues and reduce CH workload. TID-CMGR includes two mechanism including ticket ID controller, ticketing pool, route planning and other components. The CA (cluster agent) shall control and supervise the functions of nodes and inform to TID-CMGR. The CH conducts and transfers packets to the network nodes. As the CH energy level is depleted, CA elects the corresponding node with elevated energy values, and all new and old operations are simultaneously stored by CA at this time. A simulation trial for 20 to 100 nodes was performed to show the proposed scheme performance. The suggested approach is used to do experimental work using the NS- simulator. TIDCMGR is compared with TID BRM and PSO to calculate the utility of the work proposed. The assessment shows that the proposed TICKET-ID scheme achieves 90 percent more than other current systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8A
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• pp.679-687
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• 2005

A mobile ad-hoc network (MANET) is one consisting of a set of mobile hosts capable of communicating with each other without the assistance of base stations. It is necessary to use bandwidth effectively because MANET has limited bandwidth. In this paper, we propose SMGS (source based multiple gateway selection routing protocol). In SMGS, each node estimates its expected life time (ELT) and if its ELT is larger than that of current gateway it becomes a candidate node. When a source node establishes a path, in each grid the candidate node will take the route request and be a gateway node for the each source node. The node that is expected to stay the longest time in the grid is selected so that we can reduce frequent gateway handoff, packet loss, and handoff delay.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.3
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• pp.327-335
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• 2014

In this paper, we propose a group distributed dynamic address assignment scheme suitable for tactical mobile ad hoc networks(MANET). Efficient address assignment is an important issue in the MANET because a node may frequently leave the current network and join another network owing to the mobility of the node. The conventional schemes do not consider the features of the tactical networks: existence of a leader node and network activity on a group basis. Thus, they may not be suitable for military operations. In our proposed scheme, called grouped units dynamic address assignment protocol(G-DAAP), a leader node maintains the address information for the members in the network and any of the nodes can exploit the information for the assignment or request of the IP address by a simple message exchange procedure. This leads to fast address assignment with small overheads. In addition, G-DAAP based on the modified IEEE 802.11e Enhanced Distributed Channel Access(EDCA) can assign addresses more quickly. We describe the delay performance of the G-DAAP and compare it with conventional schemes by numerical analysis and computer simulations. The results show that the G-DAAP significantly improves the delay performance as compared with the conventional schemes.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.55-63
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• 2007

Multicast is an efficient transport mechanism for community communications and MANET is recently regarded as a promising solution for support ubiquitous computing as an underlying network technology. However, it is hard to deploy multicast mechanism into MANET owing to scarce resources in wireless networks and unpredictable changes in network topology. Several multicast mechanisms have been proposed in the literature to overcome the limitations. Especially, overlay multicasting schemes present several advantages over network based multicasting schemes. Yet, the overlay multicasting schemes still introduce redundant data transmissions that waste network bandwidth and battery of relay nodes. As a result the performance of the network is degraded. To reduce the redundancy, we propose an efficient way to construct an overlay structure as a multicast data delivery tree that utilizes a branch node which belongs to the tree. By using network simulation, we show that the proposed scheme presents higher packet delivery ratio and lower transmission cost than previously proposed schemes.