• Journal of Korea Multimedia Society
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• v.13 no.6
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• pp.849-864
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• 2010

This paper proposes a multipath routing protocol called cross-layer multipath AODV (CM-AODV) for wireless ad hoc networks, which selects multiple routes on demand based on the signal-to-interference plus noise ratio (SINR) measured at the physical layer. Note that AODV (Ad hoc On-demand Distance Vector) is one of the most popular routing protocols for mobile ad hoc networks. Each time a route request (RREQ) message is forwarded hop by hop, each forwarding node updates the route quality which is defined as the minimum SINR of serialized links in a route and is contained in the RREQ header. While achieving robust packet delivery, the proposed CM-AODV is amenable to immediate implementation using existing technology by neither defining additional packet types nor increasing packet length. Compared to the conventional multipath version of AODV (which is called AOMDV), CM-AODV assigns the construction of multiple paths to the destination node and makes it algorithmically simple, resulting in the improved performance of packet delivery and the less overhead incurred at intermediate nodes. Our performance study shows that CM-AODV significantly outperforms AOMDV in terms of packet delivery ratio and average end-to-end delay, and results in less routing overhead.

• 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.

• Annual Conference of KIPS
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• 2002.04b
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• pp.1539-1542
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• 2002

Many routing protocols have been proposed for mobile ad-hoc networks, but most protocols do not consider the physical location of the communicating nodes. In this paper we propose adaptive zoning approach with multiple hosts for reducing the number of route request messages. The proposed approach makes the sub-request zone has shorter interval than the existing schemes between the source and destination. This results in significantly lower routing overhead than the existing schemes as verified by computer simulation.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.136-138
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• 2006

The high-rate Wireless Personal Area Networks (WPANs) which IEEE 802.15.3 standard support, foster the Digital Home Network (DHN) scenarios with high rate multimedia data transmission. Actually, there are a few routing protocols for ad-hoc networks which considered the terminal location information and routing metric to reduce the energy consumption and optimize the routing path in mobile system. Based on other routing protocols, this paper presents the reliable location-based routing algorithm which is an adaptation to these networks.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.202-214
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• 2003

The central challenge in the design of ad-hoc networks is the development of dynamic routing protocol that efficiently finds route between mobile nodes. Several routing protocols such as DSR, AODV and DSDV have been proposed in the literature to facilitate communication in such dynamically changing network topology. In this paper, a Node Transition Probability (NTP) based routing algorithm, which determines stable routes using the received power from all other neighboring nodes is proposed. NTP based routing algorithm is designed and implemented using Global Mobile Simulator (GloMoSim), a scalable network simulator. The performance of this routing algorithm is studied for various mobility models and throughput, control overhead, average end-to-end delay, and percentage of packet dropped are compared with the existing routing protocols. This algorithm shows acceptable performance under all mobility conditions. The results show that this algorithm maximizes the bandwidth utilization during heavy traffic with lesser overhead.

• Journal of Communications and Networks
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• v.5 no.3
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• pp.266-274
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• 2003

One of the major issues in current on-demand routing protocols for ad hoc networks is the high resource consumed by route discovery traffic. In these protocols, flooding is typically used by the source to broadcast a route request (RREQ) packet in search of a route to the destination. Such network-wide flooding potentially disturbs many nodes unnecessarily by querying more nodes than is actually necessary, leading to rapid exhaustion of valuable network resources such as wireless bandwidth and battery power. In this paper, a simple optimization technique for efficient route discovery is proposed. The technique proposed herein is location-based and can be used in conjunction with the existing Location-Aided Routing (LAR) scheme to further reduce the route discovery overhead. A unique feature of our technique not found in LAR and most other protocols is the selective use of unicast instead of broadcast for route request/query transmission made possible by a novel reuse of routing and location information. We refer to this new optimization as the UNIQUE (UNIcast QUEry) technique. This paper studies the efficacy of UNIQUE by applying it to the route discovery of the Dynamic Source Routing (DSR) protocol. In addition, a comparative study is made with a DSR protocol optimized with only LAR. The results show that UNIQUE could further reduce the overall routing overhead by as much as 58% under highly mobile conditions. With less congestion caused by routing traffic, the data packet delivery performance also improves in terms of end-to-end delay and the number of data packets successfully delivered to their destinations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.6
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• pp.1586-1605
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• 2012

With the prevalence of multimedia applications and the potential commercial usage of Mobile Ad hoc Networks (MANETs) in group communications, Quality of Service (QoS) support became a key requirement. Recently, some researchers studied QoS multicast issues in MANETs. Most of the existing QoS multicast routing protocols are designed with flat topology and small networks in mind. In this paper, we investigate the scalability problem of these routing protocols. In particular, a Position-Based QoS Multicast Routing Protocol (PBQMRP) has been developed. PBQMRP builds a source multicast tree guided by the geographic information of the mobile nodes, which helps in achieving more efficient multicast delivery. This protocol depends on the location information of the multicast members which is obtained using a location service algorithm. A virtual backbone structure has been proposed to perform this location service with minimum overhead and this structure is utilized to provide efficient packet transmissions in a dynamic mobile Ad hoc network environment. The performance of PBQMRP is evaluated by performing both quantitative analysis and extensive simulations. The results show that the used virtual clustering is very useful in improving scalability and outperforms other clustering schemes. Compared to On-Demand Multicast Routing Protocol (ODMRP), PBQMRP achieves competing packet delivery ratio and significantly lower control overhead.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.795-801
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• 2008

Wireless Mesh Networks (WMNs) are popular due to their low cost and rapid deployment. Currently, many WMN researchers often considers the use of ad-hoc routing protocols because WMNs are similar to the ad-hoc networks. Some of currently deployed WMNs consider to use on-demand routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR). But, AODV are not appropriate for Wireless Mesh Networks (WMNs), because flooding-based route discovery is both redundant and expensive in terms of control message overhead. In this paper, we propose a directional AODV (D-AODV) routing protocol based on hop count to a gateway. We implement the D-AODV routing protocol and evaluate the performance of the D-AODV on the testbed. The measurement results show that the D-AODV can enhance the network throughput by reducing the routing overhead.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.798-802
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• 2008

In this paper, we consider mobile ad hoc network routing protocols with respect to content sharing applications. We show that by utilizing social relations among participants, our routing protocols can improve its performance and efficiency of caching. Moreover, in certain situation which we can anticipate pattern of user's content consumption, our scheme can help such applications be more efficient in terms of access time and network overhead. Using NS2 simulator, we compare our scheme to DSDV and routing protocol using shortest path algorithm.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.239-242
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• 2003

이 논문에서는 기존 연구 활동에 쓰이는 NS-2 시뮬레이터와 최근 대만의 National Chiao Tung University에서 개발하여 주목을 받고 있는 네트워크 시뮬레이터인 NCTUns에서 On-Demand 방식의 Ad Hoc 라우팅 프로토콜 중 AODV와 DSR의 성능을 분석하여 그 결과를 논하였다. NCTUns의 경우 작은 규모의 실험에서는 원할 한 성능을 보여주지만 노드수가 증가하면 불안정한 성능을 보여준다. 그러나 NS-2의 경우 NCTUns가 보여준 문제점 없이 원할 한 통신을 보여준다. 이에 앞으로의 실험에서는 Ad Hoc 관련 실험에서 보다 안정적인 성능을 보이고 있는 NS-2의 프로토콜 모듈을 NCTUns에 보강하면 보다 안정적인 시뮬레이터가 될 것으로 기대한다.