Byoungheon Shin

Dynamic Link Quality Aware Routing Protocol for Multi-radio Wireless Mesh Networks

Wireless mesh networks (WMNs) are promising networks in the future Internet environments due to their self-configuration and ease of deployment. Although streaming and real time applications are possible using current mobile devices, these applications still suffer from low quality. Because link failures are not reported in congested situations, the existing routing protocols do not capture these deteriorations. An extension of the AODV-MR that is adaptive to changes in link quality is proposed in order to detect deteriorated situations and to recover the path in WMNs. The path is recovered proactively by route discovery if the quality difference of the current link and other available links exceeds the threshold which is determined by the network status. The simulation results demonstrate that the proposed method is effective in multi-radio WMNs and achieve higher throughput, lower average jitter, and lower end-to-end delay.

Price-based congestion control and local channel-link assignment for multi-radio wireless mesh networks

Display Omitted We extend a price-based approach to multi-radio wireless networks.We devise a closely coupled congestion control and local channel selection framework.We demonstrate the convergence of proportional fair rate allocation by the framework.We demonstrate the convergence of max-min fair rate allocation. In multi-radio multi-channel wireless mesh networks, engineering the network capacity requires a complex cross-layer design. In this paper, in order to make the complex problem implementable in a distributed manner, we make a decoupling approach that breaks down the entire design space into routing and initial channel assignment, and distributed congestion control and local channel reassignment. We propose a unified priced-based framework for distributed congestion control and localized channel-link assignment algorithms. We demonstrate the convergence of the proposed algorithms with respect to different fairness objectives (i.e., proportional fairness and max-min fairness) via simulation on both grid and random topologies. The proposed algorithms achieve faster convergence with less overhead in the control and forwarding plane than previous multi-path based algorithms.

A Dynamic Packet Fragmentation Extension to High Throughput WLANs for Real-Time H264/AVC Video Streaming

This paper proposes an extension to high throughput WLANs such as IEEE 802.11n and IEEE 802.11ac for efficient streaming of H264/AVC encoded videos. The main idea is to fragment IP packets containing several TS packets into smaller IP packets containing fewer TS packets which leads to higher transmission success rate and TS level prioritization of H264/AVC frames. Unlike existing fragmentation schemes, it is done without any modification to the MAC layer at the receiver side. Evaluation results show that the proposed scheme achieves up to 5 dB gain on PSNR and 3.5 times higher goodput than legacy WLANs.

Application-awareness support for QoS-aware routing protocols in wireless ad-hoc networks

In order to support QoS in wireless ad-hoc networks, each node needs to monitor the network status and to determine whether the current network status satisfies the requirements of an application or not. Since the network requirements on an intermediate node are usually different from those on the end nodes, there is a need to convert the application requirement into a hop-by-hop network requirement. This paper induces link validation formulas for each node to determine if a link can satisfy the requirement of a specific application. The simulation results show the effectiveness of application-awareness on discovering appropriate routes for a specific application type in wireless ad-hoc networks.

Semantic virtualization for Edge-IoT cloud: issues and challenges

It is well expected that a collection of smart objects such as IoT devices dynamically form an edge cloud allowing acquiring, storing, communicating, and processing of information done at the edge of the network. Edge cloud workers (i.e. IoT devices) usually have service specific characteristics while legacy cloud workers are more computing oriented. However, existing cloudlet architectures continue to take their allocation policy centered around computation resource virtualization without considering such characteristics of edge IoT clouds. In order to provide service specific QoS driven virtualization of an edge IoT cloud, which we call semantic virtualization, a new approach is required. In this paper, we investigate research issues and directions for realizing semantic virtualization for an edge IoT cloud.

A Multi-Dimensional Smart Community Discovery Scheme for IoT-Enriched Smart Homes

The proliferation of the Internet into every household has provided more opportunities for residents to become closer to each other than before. However, solid structural barrier is raised and social relationships within such neighborhoods are weak compared to those in traditional towns. Accordingly, activating communities and ultimately enhancing a sense of community through constructive participation and communal sharing of labor among residents has currently emerged as a challenging issue in a contemporary housing complex. In an effort to activate those communities, a notion of smart community is presented in which multiple smart homes are equipped with Internet of Things and interconnected with each other. Beyond the unadorned smart community composed by physical proximity, it is essential to discover a human-centric community that achieves communal benefits and enables residents to maximize individual economic gain by leveraging collective intelligence. In this article, we present a multi-dimensional smart community discovery scheme that enables householders to find human-centric community considering multi-dimensional factors in terms of physical, social, and economical aspects. We conduct experiments with 30 real households by applying a community-based energy saving scenario. Experiment results show that the proposed scheme performs better when compared to the physical proximity-based one in energy consumption and user satisfaction.

CASPRE: A context-aware standby power reduction scheme for household appliances

Many household appliances draw standby power, which can be reduced to save total energy consumption of a household. Smart plugs are proposed for effectively reducing standby power of an appliance by monitoring and cutting power when the appliance is no longer in use. However, the level of intelligence it leverages is minimal such that it still requires a direct manipulation by the user and does not make a use out of any other contexts. In this paper, we propose a context-aware standby power reduction scheme, CASPRE that reduces the total standby power of household appliances by controlling smart plugs through context reasoning. The proposed scheme leverages the notion of correlations that exist among appliances when conducting a specific task at home. An ongoing task can be inferred from contexts of multiple appliances and those that do not belong to the current task can be turned off. Experiments on real world power datasets show that the proposed scheme more effectively reduces total standby power than existing ones.

An application-driven path discovery mechanism for MANET routing protocols

In mobile ad hoc networks (MANETs), a layered approach to networks makes a routing protocol to be responsible on discovery of a path between two nodes. However, this approach has fundamental limitations in diversifying the strategies of routing in a network when various types of applications require different routing support. In this paper, we propose an application-driven path discovery mechanism. In the proposed architecture, a routing packet controller resides in each MANET node and each application can control path discovery process by installing rules in the routing packet controller. Several examples are described to show the feasibility of our approach.

Interference-aware routing protocol in multi-radio wireless mesh networks

Utilization of multiple radio interfaces increases throughput of wireless networks. Existing work proposes a multi-radio routing protocol exploiting link quality and channel diversity of a path. While an established path is deteriorated by interferences incurred by any changes in a network, and existing work does not detect the deterioration. In this paper, we propose an interference-aware multi-radio routing protocol detecting and resolving dynamic path deterioration in wireless mesh networks.

Towards Application-Aware Virtualization for Edge IoT Clouds

We explore issues and challenges for application-aware virtualization in edge Internet-of-Things (IoT) clouds. Since a large number of IoT devices reside in network edges, it is necessary for a current edge computing technology to virtualize them not only as computational resources but also functional resources for achieving the goal of a specific service, which we call application-aware virtualization. This requires translation of abstract application requirements into IoT resource allocation policies using the knowledge of relationships between application layer semantics and underlying device functionalities and status. We implement a prototype for proof-of-concept and show that it is able to dynamically allocate and reallocate IoT resources to applications according to the applications requirements and contexts changes with a reasonably small processing overhead.