Showing papers by "Choong Seon Hong published in 2011"

Data-centric multiobjective QoS-aware routing protocol for body sensor networks.

Abstract: In this paper, we address Quality-of-Service (QoS)-aware routing issue for Body Sensor Networks (BSNs) in delay and reliability domains. We propose a data-centric multiobjective QoS-Aware routing protocol, called DMQoS, which facilitates the system to achieve customized QoS services for each traffic category differentiated according to the generated data types. It uses modular design architecture wherein different units operate in coordination to provide multiple QoS services. Their operation exploits geographic locations and QoS performance of the neighbor nodes and implements a localized hop-by-hop routing. Moreover, the protocol ensures (almost) a homogeneous energy dissipation rate for all routing nodes in the network through a multiobjective Lexicographic Optimization-based geographic forwarding. We have performed extensive simulations of the proposed protocol, and the results show that DMQoS has significant performance improvements over several state-of-the-art approaches.

An Adaptable Mobility-Aware Clustering Algorithm in vehicular networks

Abstract: The forthcoming Intelligent Transportation System aims to achieve safety and productivity in transportation using vehicular ad hoc networks (VANETs) to support the communications system required. Currently, some clustering approaches have been proposed to improve the performance of VANETs due to their dynamic nature, high scalability and load balancing results. However, the host mobility and the constantly topology change continue to be main problems of this technique due to the lack of models which represent the vehicular behavior and the group mobility patterns. Therefore, we propose an Adaptable Mobility-Aware Clustering Algorithm based on Destination positions (AMACAD) to accurately follow the mobility pattern of the network prolonging the cluster lifetime and reducing the global overhead. In an effort to show the efficiency of AMACAD, a set of simulation was executed. The obtained results reveal an outstanding performance in terms of the lifetime of the cluster heads, lifetime of the members and the re-affiliation rate under varying speeds and transmission ranges.

Medium access control for power line communications: an overview of the IEEE 1901 and ITU-T G.hn standards

Abstract: Power lines are becoming increasingly popular for high-speed communications, while at the same time reliable communications over them poses several unique challenges. Recently, two standardization bodies, the Institute of Electrical and Electronics Engineers (IEEE) and the International Telecommunication Union (ITU), addressed in their IEEE 1901 and ITU-T G.hn standards, respectively, both the medium access control and the physical layer specifications of power line communications. In this article, we provide an overview of these standards from the media access control technology perspective, and the similarities and dissimilarities between the IEEE 1901 and ITU-T G.hn standards are discussed, as well as potential performance issues. We use a top-down approach to analyze the features and technologies of the standards.

ATLAS: A Traffic Load Aware Sensor MAC Design for Collaborative Body Area Sensor Networks

Abstract: In collaborative body sensor networks, namely wireless body area networks (WBANs), each of the physical sensor applications is used to collaboratively monitor the health status of the human body. The applications of WBANs comprise diverse and dynamic traffic loads such as very low-rate periodic monitoring (i.e., observation) data and high-rate traffic including event-triggered bursts. Therefore, in designing a medium access control (MAC) protocol for WBANs, energy conservation should be the primary concern during low-traffic periods, whereas a balance between satisfying high-throughput demand and efficient energy usage is necessary during high-traffic times. In this paper, we design a traffic load-aware innovative MAC solution for WBANs, called ATLAS. The design exploits the superframe structure of the IEEE 802.15.4 standard, and it adaptively uses the contention access period (CAP), contention free period (CFP) and inactive period (IP) of the superframe based on estimated traffic load, by applying a dynamic "wh" (whenever which is required) approach. Unlike earlier work, the proposed MAC design includes load estimation for network load-status awareness and a multi-hop communication pattern in order to prevent energy loss associated with long range transmission. Finally, ATLAS is evaluated through extensive simulations in ns-2 and the results demonstrate the effectiveness of the protocol.

eMCCA: An enhanced mesh coordinated channel access mechanism for IEEE 802.11s wireless mesh networks

Abstract: In this paper, we present a channel access mechanism, referred to as the enhanced mesh coordinated channel access (eMCCA) mechanism, for IEEE 802.11s-based wireless mesh networks. The current draft of IEEE 802.11s includes an optional medium access control (MAC), denoted as MCCA, which is designed to provide collision-free and guaranteed channel access during reserved periods. However, the MCCA mechanism fails to achieve the desired goal in the presence of contending non-MCCA nodes; this is because non-MCCA nodes are not aware of MCCA reservations and have equal access opportunities during reserved periods. We first present a probabilistic analysis that reveals the extent to which the performance of MCCA may be affected by contending non-MCCA nodes. We then propose eMCCA, which allows MCCA-enabled nodes to enjoy collision-free and guaranteed channel access during reserved periods by means of prioritized and preemptive access mechanisms. Finally, we evaluate the performance of eMCCA through extensive simulations under different network scenarios. The simulation results indicate that eMCCA outperforms other mechanisms in terms of success rate, network throughput, end-to-end delay, packet-loss rate, and mesh co- ordinated channel access opportunity-utilization.

A mechanism for building Ad-hoc social network based on user's interest

Abstract: In social networks, user profile can be used as an important factor to define the character of a user and divide users in many social groups and provide suitable services to each social group. Recently, launched mobile devices can perform many functions, such as taking pictures, listening to music, web browsing etc. So, a mobile device can collect a user's data in his/her daily life and create his/her profile. In this paper, we propose a novel system, which can create a user profile automatically based on collected data from a mobile device and build an Ad-hoc social network.

Method for supporting the mobility of a device in a 6lowpan-based wireless sensor network

Abstract: The present invention relates to a method for supporting the mobility of a device in an Internet Protocol version 6 (IPv6)-based wireless sensor network, and more particularly, to a method for supporting the mobility of a device by separating the identifier (ID) and the locator of the device in an IPv6 Low-power Wireless Personal Area Network (6LoWPAN)-based wireless sensor network.

MPCubic: An extended cubic TCP for multiple paths over high bandwidth-delay networks

Abstract: Cubic TCP nowadays is one of transport protocols designed for high bandwidth-delay networks has successfully deployed in the Internet. Multi-homed computers with multiple interfaces to access the Internet via high speed links will become more popular. In this work, we introduce an extended version of Cubic TCP for multiple paths, called MPCubic. The extension process is approached from analysis model of Cubic with constraining coordinated congestion control between paths, and fairness to regular Cubic. Therefore MPCubic can spread its traffic across paths in load-balancing manner, while preserving fair sharing with regular TCP, Cubic, and MPTCP at common bottlenecks. Our simulation results show that MPCubic can achieve stability, throughput improvement, fairness, and load-balancing.

A policy based management framework for machine to machine networks and services

Abstract: With the penetration of smart-devices and intelligent home-appliances, M2M (machine to machine) communication has opened the door of new prospects for us. The success of such M2M networks depends on its human involvements at the least possible level. In this context, policy based management has huge potentials to be used for M2M communication. This paper presents such a policy based management framework for M2M networks and services. We have considered two M2M communication platforms namely smart-devices and sensor network in our system.

A lightweight temperature scheduling routing algorithm for an implanted sensor network

Abstract: Modern diagnosis system has been evolved to equip human being with advanced health-service. In vivo sensors have come up to contribute in this field with its support in miniature, complex operation as implanted in a human body. Implanted sensor solutions like artificial retina, pacemaker and implanted cardioverter defibrillators, insulin pump, glucose monitor — are remarkable inventions in medical science. But, these implanted sensor nodes exhibit temperature at packet transmission or processing time that can be dangerous for surrounding human tissues. With the advancement of wireless communication and sensor network technology, thermal aware routing algorithms have been proposed for this type of sensor network. But, these algorithms suffer from disadvantages like hotspot creation, computational complexity overhead or redundant hop traversal etc. We also have to consider energy constraints like limited battery life of this miniature form of sensor nodes. We have tried to solve these problems with lightweight event-based communication (publish-subscribe system) in this type of sensor network. We have proposed a lightweight temperature scheduling routing algorithm for this implanted sensor network. Proposed routing protocol is considered to schedule temperature in implanted sensor nodes deployed in the joint operation of cancer hyperthermia, radio-therapy and chemo-therapy.

Method of operating user information-providing server based on users moving pattern and emotion information

Abstract: The present invention relates to a method of analyzing user's behaviors based on a moving pattern of the user, and more particularly, to a method of operating a user information-providing server, in which behaviors of the user can be analyzed by providing information on user's emotion which varies depending on a moving pattern of the user, together with the moving pattern of the user, to the user or a counterpart. The inventive user information-providing server operating method provides information on user's emotion inferred using user's biological information obtained from a variety of sensors, information on a place where the user is positioned, and information on a counterpart, so that user's behaviors applicable to various fields can be accurately determined based on simple user's moving patterns and user information varying depending on the user's moving pattern. In addition, user's behaviors varying depending on the obtained counterpart information can be determined.

Joint Rate and Power Control for Elastic and Inelastic Traffic in Multihop Wireless Networks

Abstract: The current optimal joint rate and power control algorithms for wireless networks are mainly for elastic traffic which has strictly concave utility functions. In the multiclass service networks such that elastic and inelastic, the inelastic traffic is usually associated with the sigmoidal utilities which are nonconcave functions. Therefore, the corresponding Network Utility Maximization (NUM) problem is nonconvex in both objective and constraints. The current approaches cannot be applied and the problem is difficult to solve for the global optimal solution even with the centralized method. This paper proposes the joint rate and power control algorithm which can be distributively implemented. We approximate the nonconvex NUM to the convex problem which is easily solved by dual decomposition method. After a series of approximations, the algorithm converges the local optimal solution.

Joint rate adaption, power control, and spectrum allocation for OFDMA-based multi-hop CRNs

Abstract: The overall performance of multi-hop cognitive radio networks (CRNs) can be improved significantly by deploying the channel diversity of orthogonal licensed channels in spectrum underlay fashion. However, interference due to the sharing of common radio channels among links and congestion due to the contention among those flows that share the same link become an obstacle to meet this challenge. How to control congestion efficiently and allocate power as well as channel optimally in order to obtain a high end-to-end throughput motivates a framework of cross-layer optimization design for OFDMA-based multi-hop CRNs. By taking into account the problem of joint rate adaption, power control, and spectrum allocation (JRPS), we propose a new cross-layer optimization framework. The formulation is shown to be a mix-integer non-linear programming (MINLP) problem, which is NP-hard in general. To solve the problem, we develop a partially distributed solution, which has been proved to converge to the global optimum within reasonable times.

nW-MAC: multiple wake-up provisioning in asynchronously scheduled duty cycle MAC protocol for wireless sensor networks

Abstract: To reduce the energy cost of wireless sensor networks (WSNs), the duty cycle (i.e., periodic wake-up and sleep) concept has been used in several medium access control (MAC) protocols. Although these protocols are energy efficient, they are primarily designed for low-traffic environments and therefore sacrifice delay in order to maximize energy conservation. However, many applications having both low and high traffic demand a duty cycle MAC that is able to achieve better energy utilization with minimum energy loss ensuring delay optimization for timely and effective actions. In this paper, nW-MAC is proposed; this is an asynchronously scheduled and multiple wake-up provisioned duty cycle MAC protocol for WSNs. The nW-MAC employs an asynchronous rendezvous schedule selection technique to provision a maximum of n wake-ups in the operational cycle of a receiver. The proposed MAC is suitable to perform in both low- and high-traffic applications using a reception window-based medium access with a specific RxOp. Furthermore, per cycle multiple wake-up concept ensures optimum energy consumption and delay maintaining a higher throughput, as compare to existing mechanisms. Through analysis and simulations, we have quantified the energy-delay performance and obtained results that expose the effectiveness of nW-MAC.

Congestion-aware fair rate control in wireless mesh networks

Abstract: This paper presents a fair and efficient rate control mechanism, referred to as congestion-aware fair rate control (CFRC), for IEEE 802.11s-based wireless mesh networks. Existing mechanisms usually concentrate on achieving fairness and achieve a poor throughput. This mainly happens due to the synchronous rate reduction of neighboring links or nodes of a congested node without considering whether they actually share the same bottleneck or not. Furthermore, the achievable throughput depends on the network load, and an efficient fair rate is achievable when the network load is balanced. Therefore, existing mechanisms usually achieve a fair rate determined by the mostly loaded network region. CFRC uses an AIMD-based rate control mechanism which enforces a rate-bound to the links that use the same bottleneck. To achieve the maximum achievable rate, it balances the network load in conjunction with the routing mechanism. Furthermore, it allows the intra-mesh flows to utilize the network capacity, and the intra-mesh flows achieve a high throughput. Finally, we investigate the performance of CFRC using simulation in ns-2, and the results demonstrate that CFRC increases the throughput with the desired fairness.

A social P2P networking based on interesting keywords

Abstract: Recently, one of the most popular applications on the Internet is the social networking, such as, Facebook and Twitter. Finding resources using recent Peer-to-Peer (P2P) schemes in a social network has limits, such as distance problem between peers etc. So, in this paper, we present an efficient social P2P management scheme based on interesting keywords. We compare our proposal with the recent P2P scheme to evaluate the interesting keyword based P2P.

Method for controlling handoff of IEEE 802.22 network-based mobile terminal

Abstract: The present invention relates to a method for controlling handoff of a mobile terminal, and more specifically, to a method for controlling handoff of a mobile terminal in an IEEE 802.22 wireless regional area network (WRAN) communication standard for defining communication of a fixed terminal which uses a frequency band that is not regionally used among television broadcasting frequency bands.

An efficient MAC scheme with modified RTS/CTS of IEEE P1901

Abstract: According to multimedia service distribution such as High-Definition Television (HDTV), Internet Protocol Television (IPTV) and Voice Over Internet Protocol (VoIP), the networks are required to guarantee Quality of Service (QoS) and real-time performance. Power Line Communication Technology is used for data transfer as well as the transfer of electric power. However, power line communication has some problems in wireless communication such as a noise and hidden station problem. And MAC cycle is synchronized with AC cycle of power line. MAC scheme is week in real time data transmission with short cycle. Therefore, in this paper, we propose a new MAC scheme for realtime service. Proposed scheme uses new message called TRINFO. It has scheduling information and is added to the RTS/CTS message. And we divide MAC cycle between time slot request region and data transmission region. Finally, there is a simulation with MAC performance of IEEE P1901 standard and the proposed MAC. Simulation result shows that a proposed scheme outperforms existing standards from the viewpoints of jitter and delay.

An efficient destination-based data management policy for vehicular networks

Abstract: The Vehicular Ad hoc Network (VANET) takes the advantage of the relative mobility of the vehicles to opportunistically share dynamic information when they meet, aiming to avoid accidents and traffic jams, get local information of the nearby places, enjoy entertainment applications among others. However, the shared information must be handled properly, saving bandwidth and tackling the unnecessary duplication of data, preventing the scalability problem and congestion. The current solutions of these problems incorporate the concept of Relevance to share the information in a clever way but they do not exploit the advantage of knowing the destination of the vehicles and context-aware services to follow behavior patterns. Therefore, we propose an efficient destination-based data management policy, which follows the vehicular behavior and context to determine the relevance or importance of the information using a publisher/subscriber model and cluster-based dissemination. In order to demonstrate the feasibility of the proposal we implemented sets of simulation in which the results reported an outstanding performance in terms of congestion and delivery ratio.

Power Control for Cognitive Radio Networks

Abstract: In this paper, we propose the power control problem for cognitive radio networks (CRNs) that maximizes the total utility of the secondary users (SUs). We use the interference temperature constraints to protect the primary users (PUs). The utility functions of SUs can be any increasing functions. We formulate the power control problem as monotonic optimization that can be solved in centralization to achieve the global optimum.

Distributed IDS for efficient resource management in wireless sensor network

Abstract: Intrusion detection system (IDS) is one of the basic components of network security. IDS can use signatures or abnormal behaviors to detect attacks. When IDS uses signatures, in order to detect more attacks, we have to implement more attack signatures on IDS. However, in resource-constrained wireless sensor networks, it is not efficient to implement all of attack signatures. And it is hard to maintain attack signature database because it should be updated frequently when new kind of attacks appear. In this paper, we propose a distributed IDS mechanism which reduces the usage of memory and overhead. Analysis of our proposal shows that our proposal requires less memory.

A light-weight channel rendezvous scheduling for multi-channel medium access in sensor networks

Abstract: In this paper, we present an efficient channel rendezvous (i.e., sender and receiver communicate on the same channel) scheduling for multi-channel medium access control (MAC) in wireless sensor networks (WSNs). The proposed scheme mainly targets to implement an efficient medium access control that can cope-up and adapt with the mostly available dynamic and diverse traffic environments of WSNs. To do so, the duty-cycle (periodic wake-up and sleep under low traffic) and multi-channel (at heavy traffic) concepts are applied for the proposed channel rendezvous and medium access design. Unlike earlier works the given approach is asynchronously scheduled and avoids the time-synchronization overhead in maintaining the node's cycles for channel rendezvous as well as the time-slotted medium access in data communication. Finally, the protocol is evaluated through extensive simulations and we have observed the efficiency of the proposed work over few existing schemes.

Priority-Based STDMA Scheduling Algorithm to Enhance Throughput and Fairness in Wireless Mesh Networks

Abstract: The aggregate throughput of wireless mesh networks (WMNs) can be significantly improved by equipping the mesh routers with multiple radios tuned to orthogonal channels. Not only the links using orthogonal channels can be activated at a time, but some links in the same channel also can be activated concurrently if the Signal-to-Interference-and-Noise Ratio (SINR) at their receivers is not lower than the threshold, which is the spatial-reuse characteristic. STDMA is considered as one of the medium access schemes that can exploit spatial reuse to improve network throughput. Past studies have shown that optimizing the performance of STDMA is NP-Hard. Therefore, we propose a STDMA-based scheduling algorithm that operates in a greedy fashion for WMNs. We show that the proposed algorithm enhances not only the throughput but also the fairness by capturing the essence of spatial-reuse approach of STDMA and giving medium access opportunities to each network element based on its priority. We furthermore validate our algorithm through theoretical analysis and extensive simulations and the results show that our algorithm can outperform state-of-the-art alternatives.

Grid middleware for invivo sensor nodes

Abstract: Energy limitation, heterogeneity of hardware, increase in node temperature, absence of software reusability-are major problems in existing middleware for body sensor networks. In this paper, we have proposed an event based grid middleware that solves all these problems using distributed resources. In our multi-hop communication, we have used lightweight rendezvous routing algorithm on publish/subscribe system of event based communication. To faciliate software re-use and application development, modified OSGI has been implemented in our middleware architecture. We have considered our grid middleware on a scenerio of cancer treatment with join operations of hyperthermia, chemo-therapy and radio-therapy with invivo sensors.

Solving interoperability problem of SIP, H.323 and Jingle with a middleware

Abstract: This paper presents a mobile middleware that solves interoperability problems occurred in VoIP protocols (SIP, H.323, Jingle and their different vendor implementations) and uses distributed shared objects to overcome scarce resource problem of mobile devices.

A cross-layer design for resource allocation and congestion control in multichannel multi-hop cognitive radio networks

Abstract: Efficient and fair resource allocation associated with congestion control in multi-hop cognitive radio networks (CRN) is a challenging problem. In this paper, we consider their mutual relationship through formulating a cross-layer optimization problem which addresses both the aggregate utility maximization and energy efficiency. By primal-dual method, the optimal solution is obtained via a distributed algorithm while keeping the outage probability on primary links below the allowable thresholds. The attraction of our proposed algorithm is that we utilize the broadcast property of wireless medium for message passing in power control and preserve the existing TCP stack for congestion control mechanism.

Transmission Rate Setting for the Gray Zone Problem in IEEE802.11 based MANETs

Abstract: In wireless ad-hoc networks, one of the reasons that increase the data packet loss rate is gray zone effect. The gray zone effect can happen when broadcasting control packets with lower rate while transmitting the data packets with such higher rate or the same PHY data rate. In this case, nodes are able to find valid routes but some data packets may not reach the destination, which causes the high packet loss rate. Most research efforts so far have attempted to modify the routing protocol to take the gray zone effect into consideration. This method, however, could have a detrimental performance owning to its high computational complexity. In this paper, by adjusting the suitable broadcast rate and data transmission rate, we can obtain higher throughput than the original way. By simulations, we show that our simple approach can improve throughput significantly.

A hierarchical mapping system approach for ID-to-Locator resolution

Abstract: Internet Default Free Zone (DFZ) is facing today a serious scalability problem due to the double use of the current Internet Protocol (IP) name space. IP name space today is used both for location and identification of a host. To solve this problem, Identifier and Locator separation approach was proposed and implemented in many schemes. However, the big challenge in the separation approach is how to map a given Identifier to the appropriate Locator. In this paper, we propose a hierarchical mapping system based on Internet hierarchy of IP allocation/assignment authorities. We evaluate our mapping system and show that beside the fact of removing the use of overlay networks scalability, and short lookup time can be achieved.

Interference-limited Resource Allocation in Cognitive Radio Networks with Primary User Protection.

Abstract: The performance of multihop cognitive radio networks (CRN) can be improved significantly by using multiple channels in spectrum underlay fashion. However, interference due to the sharing of common radio channel and congestion due to the contention among those flows that share the same links become an obstacle to meet this challenge. How to control efficiently congestion and allocate power optimally to obtain a high end-to-end throughput is a key objective in this work. We reexamined the Network Utility Maximum (NUM) problem with a new primary outage constraint and proposed a novel resource allocation strategy to solve it effectively and efficiently.

LETTER Fast Configuration for Mobile IPTV in IPv6 Networks

Abstract: SUMMARY This letter proposes a new fast network configuration scheme that realizes an IP interface that allows users to view Internet Protocol TV (IPTV) in IPv6 networks more quickly than is possible with the current configuration procedure. The new scheme, a hybrid combination of IPv6, address information, and non-IP information, especially the Domain Name Service, is newly designed based on a technical analysis. The evaluation results show that the proposed scheme is acceptable for real-time