• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1354-1372
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• 2012

Route establishment in Mobile Ad Hoc Network (MANET) is the key mechanism to a successful connection between a pair of source and destination nodes. An efficient routing protocol constructs routing path with minimal time, less routing overhead and capable of utilizing all possible link connectivity. In general, most on-demand MANET routing protocols operates over symmetrical and bidirectional routing path, which is infeasible due to the inherent heterogeneous properties of wireless devices. Simulation results show that the presence of unidirectional links on a network severely affect the performance of a routing protocol. In this paper, a robust protocol independent scheme is proposed, which enable immediate rediscovery of alternative route for a path blocked by a unidirectional link. The proposed scheme is efficient; route rediscovery is locally computed, which results in significant minimization of multiple route packets flooding. Nodes may exploit route information of immediate neighbors using the local reply broadcast technique, which then redirect the control packets around the unidirectional links, therefore maintaining the end-to-end bidirectional connection. The proposed scheme along with Ad Hoc On-demand Distance Vector (AODV) and AODV-Blacklist routing protocol is investigated over three types of mobility models. Simulation results show that the proposed scheme is extremely reliable under poor network conditions and the route connectivity can be improved by as much as 75%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.12
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• pp.4451-4466
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• 2014

We present joint radio selection and relay scheme that delivers data from a source to a sink in heterogeneous stationary sensor networks consisting of various radio interfaces. The proposed scheme finds the optimal relay nodes and their corresponding radio interfaces that minimize energy consumption throughout the network while satisfying the end-to-end packet deadline requirement. We formulate the problem of routing through radio interface selection into binary integer programs, and obtain the optimal solution by solving with an optimization solver. We examine a trade-off relationship between energy consumption and packet delay based on network level simulations. We show that given the end-to-end deadline requirement, our routing algorithm finds the most energy-efficient routing path and radio interface across mesh hops. We demonstrate that the proposed routing scheme exploits the given packet delivery time to turn into network benefit of reducing energy consumption compared to routing based on single radio interface.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.4
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• pp.177-186
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• 2019

In wireless sensor networks, the transmission success ratio would be decreased when the scale of the WSNs increased. To defeat this problem, we propose a multipath routing based on opportunistic routing for improving end-to-end reliability in large-scale wireless sensor networks. The proposed scheme exploits the advantages of existing opportunistic routing and achieves high end-to-end success ratio by branching like a multipath routing through local decision without information of the whole network. As a result of the simulation result, the proposed scheme shows a similar or higher end-to-end transmission success ratio and less energy consumption rather than the existing scheme.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.16-27
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• 2014

In this paper, we propose an efficient grid based routing scheme using the location information in order to reduce the routing cost in mobile ad-hoc networks. In our proposed scheme, all nodes can be a candidate to forward messages to the specified destination node and reduce the management cost of head nodes because they do not exist. The intermediate nodes determine the next hop relaying messages on the basis of location relations between a node and a grid zone. The proposed scheme explores the routing path considering the direction of a node using the coordinate of a grid zone and neighbor node information. It also maintains the routing path considering connectivities among the nodes. In order to show the superiority of the proposed routing scheme, we compare it with the existing grid based routing scheme in terms of the overhead of message, the success rate of transmission.

• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.135-140
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• 2002

An efficient QoS routing scheme needs to find a path that satisfies a given QoS requirements while consuming as few resources as Possible. In this paper, we propose two schemes of calculating resources'costs one for on-demand and one for precomputation QoS routing schemes. These schemes are effective in respect to the global network utilization and the balanced use of network resources. We also propose a QoS routing scheme for transit and Intra traffic in a large scale of domain-based network. For a domain in the network, the routing scheme first precomputes K multip1e paths between all pairs of ingress and ogress border routers while considering balancing of the expected load. We, therefore, expect that the paths are bettor than any other paths in respect to reserving the network resources on Paths. The routine: scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme. cote that our cost calculation schemes for both kinds of traffic could be used in existing QoS routing protocols without and modification in small and large scale of networks.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.507-511
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• 2008

Supporting energy efficiency and load balancing in wireless sensor network is the most important issue in devising the hierarchical routing protocols. Recently, the dual layered clustering scheme with GPS was proposed for the supporting of load balancing for cluster heads but there would be many collided messages in the overlapped area between two layers. Thereby, the purpose of this paper is to reduce the collision rate in the overlapped layer by concisely distinguish them with the same number of nodes in them. For the layer partition, this paper uses an equation $x^2+ y^2{\le}(\frac{R}{\sqrt{2\pi}})^2$ to distinguish layers. By using it, the scheme could efficiently distinguish two layers and gets the balanced number of elements in them. Therefore, the proposed routing scheme could prolong the overall network life cycle about 10% compared to the previous two layered clustering scheme.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.11-20
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• 1997

It is a recent trend that mobile communications and PCS are intergrated into the broadband network. Broadband mutlimedia traffic will be transported over the integrated network. In this paper, we propose a connection re-routing method for fast inter-switch hadoffs and dynamic resurce reservation scheme, which is based on the proposed re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing, the proposed re-routing method is to reserve VPI/VCIs for possible inter-swich handoff calls in advance. Our reservation scheme is to statistically reserve the fixed resources for possible inter-switch handoff calls, according to the QoS of the handoff calls. The simmulation reslts show that our proposed scheme satisfies the required QoS of handoff calls and keep the dropping probability of handoff calls lower than other schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2534-2553
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• 2018

Source routing is the routing scheme that arranges the whole path from source to target at the origin node that may suit the requirements from the upper layer applications' perspective. The centralized control in SDN (Software-Defined Networking) networks enables the awareness of the global topology at the controller. Therefore, augmented source routing schemes can be designed to achieve various purposes. This paper proposes a source routing scheme that conducts the top-K QoS-aware paths discovery in SDN. First, the novel non-invasive QoS over LLDP scheme is designed to collect QoS information based on LLDP in a piggyback fashion. Then, variations of the KSP (K Shortest Paths) algorithm are derived to find the unconstrained/constrained top-K ranked paths with regard to individual/overall path costs, reflecting the Quality of Service. The experiment results show that the proposed scheme can efficiently collect the QoS information and find the top-K paths. Also, the performance of our scheme is applicable in QoS-sensitive application scenarios compared with previous works.

• Journal of Communications and Networks
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• v.11 no.4
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• pp.327-336
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• 2009

Geographic routing has been considered as an attractive approach in wireless sensor networks, since it routes data packets by using location information rather than global topology information. In geographic routing schemes, packets are usually sent along the boundary of a hole by face routing to detour the hole. As result, all data flows which need to detour the hole are concentrated on the boundary of the hole. This hole detour scheme results in much more energy consumption for nodes at the hole boundary, and the energy exhaustion of hole boundary nodes enlarges the holes. This is referred to as a hole diffusion problem. The perimeter mode may also lead to data collisions on the hole boundary nodes if multiple data flows need to bypass a hole simultaneously. In this paper, we propose a hole modeling and detour scheme for geographic routing in wire-less sensor networks. Our hole modeling and detour scheme can efficiently prevent hole diffusion, avoid the local minimum problem faced by geographic routing protocols, and reduce data collisions on the hole boundary nodes. Simulation results show that the proposed scheme is superior to the other protocols in terms of control overhead, average delivery delay and energy consumption.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.671-678
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• 2002

In this paper, we propose hierarchical inter-domain load balanced QoS routing in a large scale of network. And a scheme of calculating resources'costs for precomputation schemes in hierarchical routing is proposed, and a scheme for selecting a path among multiple precomputed paths is proposed. We also propose a QoS routing scheme for transit and intra traffic in a large scale of domain-based network. For a domain in the network, the routing scheme first precomputes K multiple paths between all pairs of ingress and egress border routers while considering balancing of the expected load then selects paths with the probability of path selection. The routing scheme combines inter and intra domain routings seamlessly and uses the same cost calculation scheme. And these schemes make possible both global network resources' utilization and also load balancing.