Dabin Kim

Improving the reliability of IEEE 802.11s based wireless mesh networks for smart grid systems

A challenge faced by smart grid systems is providing highly reliable transmissions to better serve different types of electrical applications and improve the energy efficiency of the system. Although wireless networking technologies can provide highspeed and cost-effective solutions, their performance may be impaired by various factors that affect the reliability of smart grid networks. Here, we first suggest the use of IEEE 802.11s-based wireless LAN mesh networks as high-speed wireless backbone networks for smart grid infrastructure to provide high scalability and flexibility while ensuring low installation and management costs. Thereafter, we analyze some vital problems of the IEEE 802.11s default routing protocol (named hybrid wireless mesh protocol; HWMP) from the perspective of transfer reliability, and propose appropriate solutions with a new routing method called HWMP-reliability enhancement to improve the routing reliability of 802.11s-based smart grid mesh networking. A simulation study using ns-3 was conducted to demonstrate the superiorityof the proposed schemes.

Cache capacity-aware CCN: Selective caching and cache-aware routing

Content-centric networking (CCN) is a new networking paradigm to resolve the data traffic explosion problem of the Internet caused by rapid increase in file sharing and video streaming traffic. Networks with CCN avoid delivery of the same contents on one link as many times as they are requested, as contents can be stored and transferred by the cache of CCN routers. Two major features that are currently considered in CCN are in-network caching and content-aware routing. Even though both aspects are important, there is little work on the comprehensive interaction between them. In this paper, we propose the cache capacity-aware CCN which consists of selective caching and cache-aware routing methods that interacts with each other to encompass cache management and cache-aware request forwarding. The main motivation of the proposed scheme is to utilize the network caches evenly and redirect a content request based on the past forwarding of the desired contents (or chunks). To enable this function, we utilize a cache capacity metric which is collected on forwarded content requests and reflected in the content replication with popularity information from content server. We evaluate the proposed scheme against existing cache replication algorithms and show that it leads to better utilization of network caches with significant performance improvements.

Cache capacity-aware content centric networking under flash crowds

Content-centric networking (CCN) is a new networking paradigm to resolve the explosion of data traffic on the Internet caused by the rapid increase in file sharing and video streaming traffic. Networks with CCN avoid repeatedly delivering the same content of a link every time it is requested, as the content can be stored and transferred by CCN router caches. Two major features that are currently considered in CCN are in-network caching and content-aware routing. Even though both aspects are important, there is little comprehensive work on the interaction between them. In this paper, we propose a cache capacity-aware CCN that consists of selective caching and cache-aware routing methods that interact with each other to encompass cache management and cache-aware request forwarding. The main motivation of the proposed scheme is to utilize the network caches evenly and redirect a content request based on the previous forwarding of the desired contents (or chunks). To enable this function, we utilize a cache capacity metric based on recent cache memory consumption and reflect it to content replication according to the popularity information on the content server. We evaluate the proposed scheme with respect to existing cache replication algorithms and show that it leads to significant performance improvements and a better utilization of network caches.

A smart home solution over CCN

Content-centric network (CCN) [1] is an emerging future network paradigm that concentrates on the content itself rather than the content owner or location information. Many research efforts have been made to apply CCN over various fields such as sensor networks, vehicular networks, mobile ad-hoc networks, disaster recovery services, machine-to-machine communications and Internet of Things (IoT). Especially, IoT is an upcoming network scenario which can tap into the benefits of CCN [2]. A smart home solution is a popular IoT application which needs inter-operability among smart devices in the home in a secure fashion. Although, this sounds like it should be a part of the everyday world; even after twenty years of its inception, it is still a developing technology. This is because of the setup, maintenance and security challenges that a smart home solution faces. CCN supports ease of naming and scoping, security and as a platform for providing the devices connectivity to the outside world without the need of any translation gateway.

On-demand anchor-based mobility support method for named data networking

Addressing producer mobility in a Named Data Networking (NDN) is one of the challenging issues in the wireless network, which causes content unreachability problem and may impede overall quality of service. To cope with this, intermediate NDN routers have to update the forwarding information of content request toward a new position of a producer as reactive as possible. Several researchers have contributed to resolving the problem, but there is still room for improvement in terms of reducing network overhead and content retrieval latency. In this paper, we propose on-demand anchor-based mobility support method which redirects consumers requests from an old position to a new position of a producer via a mobility tracking node, which is named Anchor. When producer handover occurs, the proposed scheme supports on-the-fly route redirection procedure at the old position, so it can provide better content retrieval latency by reducing retransmission delay. Our preliminary simulation study verifies that the proposed algorithm mitigates network overhead and improves the time taken for content retrieval in a mobile environment.

Implementation of a front-end and back-end NDN system for climate modeling application

Named Data Networking (NDN), one of the future Internet architecture, is recently emerging as a solution to changing traffic pattern of traditional end-to-end host-centric network systems. To achieve this, NDN has several distinctive features such as name based forwarding and in-network caching. Data-intensive science that handles large-scale experiment and simulation datasets suffers from severe problems in terms of transmitting and processing of a huge amount of datasets. In this paper, to support NDN based data-intensive science application, especially in climate modeling application, we design and implement new NDN components. Our development supports data-centric climate data file searching and publishing, which are a front-end engine in consumer and a back-end engine in producer.

Analysis of NDN repository architectures

Named data networking (NDN) is a newly proposed networking architecture, which a few network scientists believe that it is an appropriate protocol to distribute Big Data files in the network of supercomputing domain. This new scheme is organized to reduce high network congestion resulted from it. In addition to many current NDN applications, such as climate modeling data service, another supercomputing domain, its repository applications also have been developed. However, compared to the ordinary file systems, they now significantly underperform in writing operations. It will be highly likely to prevent scientists and engineers from applying NDN over their networks because it could turn to be as a system bottleneck in the performance critical area. In this paper, writing operations of those repositories will be examined and how performance can differ according to the software architectures placed in them. Finally, we will discuss optimization schemes to make it perform better in a large scaled computing system.

Developing the IEEE 802.11s based reliable Smart Grid mesh networks

Wireless Mesh Networks are suitable for providing the Smart Grid communications required for high reliability and network capacity. However there still exist several problems disturbing network reliability. In this demonstration, we propose reliable Wireless Mesh Network architecture based on IEEE 802.11s system. We will present our system architecture to increase communication reliability and evaluate the performance by implementing testbed installation.

Analysis of NDN repository architecture and its improvement for I/O intensive applications

Named data networking (NDN) has been researched to be a substitute of the conventional IPv4 Internet. Its advantages are strong security, in-network caching, and mobility support. In terms of network architecture, it emphasizes contents rather than its locations to access data after the consumers interest is routed at each node. In contrast to many NDN researches on routing, node architecture, caching, security, and other research domains, there has been a little effort on the design and architecture development of NDN based repository and its file system to save contents efficiently. So far, there are two NDN repositories, such as NDNFS and Repo-ng. They are designed to store files in NDN way so that data is sent and received over NDN network more efficiently. However, its biggest problem is the overhead when they run at I/O intensive environment, such as serving science-modelling data, which is large, sometimes over a few gigabytes. In the performance evaluation of this paper, the extent of its severity is depicted. Moreover, the investigations on those architectures will help one notice the source of the overhead. According to our findings, an enhanced metadata scheme and its management strategy will be put forward to alleviate this problem. Furthermore, some of the implementation considerations for the NDN based distributed file system for I/O intensive environment will be discussed.

Named data networking testbed for scientific data

Named Data Networking (NDN) is one of the future internet architectures, which is a clean-slate approach. NDN provides intelligent data retrieval using the principles of name-based symmetrical forwarding of Interest/Data packets and innetwork caching. The continually increasing demand for rapid dissemination of large-scale scientific data is driving the use of NDN in data-intensive science experiments. In this paper, we establish an intercontinental NDN testbed. In the testbed, an NDN-based application that targets climate science as an example data intensive science application is designed and implemented, which has differentiated features compared to those of previous studies. We verify experimental justification of using NDN for climate science in the intercontinental network, through performance comparisons between classical delivery techniques and NDN-based climate data delivery.