• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.2
• /
• pp.637-658
• /
• 2015

The development of multimedia applications has followed the development of high-speed networks. By improving the performance of mobile devices, it is possible to provide high-transfer-speed broadband and seamless mobile multicasting services between indoor and outdoor environments. Multicasting services support efficient group communications. However, mobile multicasting services have two constraints: tunnel convergence and handoff latency. In order to solve these problems, many protocols and handoff methods have been studied. In this paper, we propose inter local mobility anchor (inter-LMA) optimized handoff model for mobile multicasting services in proxy mobility IPv6 based (PMIPv6-based) networks. The proposed model removes the tunnel convergence issue and reduces the router processing costs. Further, it the proposed model allows for the execution of fast handoff operations with adaptive transmission mechanisms. In addition, the proposed scheme exhibits low packet delivery costs and handoff latency in comparison with existing schemes and ensures fast handoff when moving the inter-LMA domain.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.2
• /
• pp.37-41
• /
• 2018

As individuals generate and share various content anytime and anywhere, new networking architectures, such as content-centric networking (CCN) using the content name as a packet identifier, have been in the spotlight recently. However, the current CCN hardly takes into account node mobility problems, especially the mobility of content sources. The movement of content sources causes long delivery latency and long service disruptions. To solve that, the tunneling-based redirection scheme was proposed. However, the tunneling-based scheme requires a location-update procedure whenever the network changes, which creates many control messages and causes long latency. So, this paper presents hierarchical mobility management of mobile CCN to reduce the number of control messages and handoff latency. Performance evaluation shows that the proposed scheme can provide low control overhead, which results in network scalability.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.4A
• /
• pp.377-386
• /
• 2008

In this paper, a new handover management scheme has been proposed to reduce handover latency and to support fast handover without packet losses, so that it may be applicable to the wireless mobile Internet system such as IPv6-based WiBro system. To minimize the handover latency in processing of movement detection, we propose the handover management scheme which simplifies the handover message exchanging procedure between mobile subscriber station (MSS) and network by integrating layer 2 and layer 3 handovers efficiently based on the layer2 information. To reduce the processing delay from new care-of-address (NCoA) configuration during handover, we propose that NCoA is created, distributed and managed by new access control router (NACR). In addition, in order to minimize the packet transmission delay and eliminate the packet losses, the proposed scheme employs a crossover router (CR) which is upper network located over PACR and NACR and employs the packet buffering for MSS. The simulation study shows that the proposed scheme achieves loss-free packet delivery and low latency in the environment of narrow overlapped cell area or high velocity of the MSS, comparing the performance with the conventional schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.9 no.9
• /
• pp.3594-3610
• /
• 2015

Recent advancements in broadband wireless communication technologies enable mobile users to receive video streaming services with various smart devices. The long term evolution (LTE) network provides high bandwidth and low latency for several emerging mobile applications. This paper proposes the buffer aware scheduling (BAS) approach to schedule the downlink video traffic in LTE network. The proposed BAS scheme applies the weighting function to heuristically adjust the scheduling priority by considering the buffer status and channel condition of UE so as to reduce the time that UE stays in the connected state without receiving data. Both of 1080P and 2160P resolution video streaming sources were applied for exhaustive simulations to examine the performance of the proposed scheme by comparing to that of the fair bandwidth (FB) and the best channel quality indicator (CQI) schemes. The simulation results indicate that the proposed BAS scheme not only achieves better performance in power saving, streaming delivery time, and throughput than the FB scheme while maintaining the similar performance as the best CQI scheme in light traffic load. Specifically, the proposed scheme reduces streaming delivery time and generates less signaling overhead than the best CQI scheme when the traffic load is heavy.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.23 no.6
• /
• pp.571-576
• /
• 2013

Despite the development of the Internet, both in terms of technology and coverage, there are still remote areas and scenarios where connectivity is very difficult to achieve. Pocket Switched Network is a network paradigm that takes the advantage of human mobility to disseminate data. Factors such as mobility of nodes, link failures, discharged batteries, are among the challenges that may compromise connectivity in these networks. This paper presents a performance analysis of existing routing schemes for PSN in terms of delivery probability, overhead ratio, average latency and average residual energy when the number of nodes is increased. We seek to identify a scheme that maximizes data delivery while minimizing communication overhead and thus extending the network lifetime.

• Journal of Internet Computing and Services
• /
• v.19 no.1
• /
• pp.37-47
• /
• 2018

The number of capabilities of Internet of Things (IoT) devices will exponentially grow over the next years. These devices may generate a vast amount of time-constrained data. In the context of IoT, data management should act as a layer between the objects and devices generating the data and the applications accessing the data for analysis purposes and services. In addition, most of IoT services will be content-centric rather than host centric to increase the data availability and the efficiency of data delivery. IoT will enable all the communication devices to be interconnected and make the data generated by or associated with devices or objects globally accessible. Also, fog computing keeps data and computation close to end users at the edge of network, and thus provides a new breed of applications and services to end users with low latency, high bandwidth, and geographically distributed. In this paper, we propose Edge-Fog cloud-based Hierarchical Data Delivery ($EFcHD^2$) method that effectively and reliably delivers IoT data to associated with IoT applications with ensuring time sensitivity. The proposed $EFcHD^2$ method stands on basis of fully decentralized hybrid of Edge and Fog compute cloud model, Edge-Fog cloud, and uses information-centric networking and bloom filters. In addition, it stores the replica of IoT data or the pre-processed feature data by edge node in the appropriate locations of Edge-Fog cloud considering the characteristic of IoT data: locality, size, time sensitivity and popularity. Then, the performance of $EFcHD^2$ method is evaluated through an analytical model, and is compared to fog server-based and Content-Centric Networking (CCN)-based data delivery methods.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1993.10a
• /
• pp.461-466
• /
• 1993

This paper focuses on development and implementation of a performance management algorithm for IEEE802.4 token bus networks to serve large-sale integrated systems. The delivery of time critical messages within delay constraints is an important criterion in the design and management of computer communication networks. In order to achieve this goal, the theory of fuzzy sets has been employed to imitate human's reasoning. The Fuzzy Network Performance Manager(FNPM) is composed of two parts: FNPM1 & FNPM2. FNPM1 is solily intended to satisfy the data latencyfor the highest priority while the other part is trying to satisfy those for the lower priorities. The FNPM requires average data latency, throughput, and token circulation time for its inputs. The efficacy of the FNPM has been evaluated by a series of simulation experiments.

• Proceedings of the Korea Contents Association Conference
• /
• 2015.05a
• /
• pp.33-34
• /
• 2015

Continuous improvements of network infrastructures and mobile data offloading strategies are among the solutions of cellular providers to cope with the increase in mobile data demand. These options requires a lot of cost and time to implement. Few researches have been conducted to assess the applicability of Pocket Switched Network (PSN) to support mobile data offloading. In this paper, we present a PSN mobile data-offloading scheme that utilizes mobile users with available connectivity to deliver content-aware data to other mobile users. This paper also aims to evaluate the applicability and feasibility of PSN routing schemes to improve the current strategies in mobile data offloading. The simulation results show admirable results in terms of message delivery and latency.

• Journal of information and communication convergence engineering
• /
• v.12 no.1
• /
• pp.26-32
• /
• 2014

Vehicular-to-anything (V2X) technology is attractive for wireless vehicular ad-hoc networks (VANETs) because it allows for opportunistic choice of a vehicular protocol between vehicular-to-vehicular (V2V) and vehicular-to-infrastructure (V2I) communications. In particular, achieving seamless connectivity in a VANET with nearby network infrastructure is challenging. In this paper, we propose a density-based opportunistic broadcasting (DOB) protocol, in which opportunistic connectivity is carried out by using the nearby infrastructure and opposite vehicles for solving the problems of disconnection and long end-to-end delay times. The performance evaluation results indicate that the proposed DOB protocol outperforms the considered comparative conventional schemes, i.e., the shortest path protocol and standard mobile WiMAX, in terms of the average end-to-end delay, packet delivery ratio, handover latency, and number of lost packets.

• Electronics and Telecommunications Trends
• /
• v.35 no.5
• /
• pp.14-29
• /
• 2020

The 6G mobile communication system will become a backbone infrastructure around 2030 for the future digital world by providing distinctive services such as five-sense holograms, ultra-high reliability/low-latency, ultra-high-precision positioning, ultra-massive connectivity, and gigabit-per-second data rate for aerial and maritime terminals. The recent remarkable advances in machine learning (ML) technology have recognized its efficiency in wireless networking fields such as resource management and cell-configuration optimization. Further innovation in ML is expected to play an important role in solving new problems arising from 6G network management and service delivery. In contrast, an approach to apply ML to a physical-layer (PHY) target tackles the basic problems in radio links, such as overcoming signal distortion and interference. This paper reviews the methodologies of ML-based PHY, relevant industrial trends, and candiate technologies, including future research directions and standardization impacts.