Seil Jeon

Cost-efficient network mobility scheme over proxy mobile IPv6 network

As Wi-Fi handheld devices providing a variety of data and multimedia services become more widespread, and as the global demand for internet access everywhere rapidly increases, energy-efficient network mobility (NEMO) technology is attracting great attention with respect to the latest research in mobile networking. The previous research relating to energy-efficient networks in mobile networking has focused on routing protocol or topology control. In NEMO, cost-efficient protocol design reduces unnecessary costs because of mobility signalling and packet delivery, and saves limited network bandwidth in both wired and especially wireless, which is one of the important issues of energy efficiency. In this study, the authors propose a cost-efficient proxy router-based NEMO scheme (PR-NEMO) providing efficient mobility management and packet delivery method. In PR-NEMO, a mobile network is formed with a unique ID and the information of mobile network nodes (MNNs) within the mobile network anchored at local mobility anchor (LMA) are distributed to attached mobile access gateway (MAG). The authors analyse the performance of the PR-NEMO with the N-PMIPv6 and the rNEMO in terms of total cost; that is, sum of location update cost and packet-tunnelling cost. Numerical results demonstrate that the PR-NEMO is the most cost-efficient scheme, under various conditions, among the three schemes evaluated.

A CDN-P2P hybrid architecture with content/location awareness for live streaming service networks

Hybrid architecture of content delivery network (CDN) and peer-to-peer (P2P) is a promising network technology enabling effective real-time streaming services. It complements the advantages of quality control and reliability in CDN and the scalability in the P2P system. With real-time streaming services, however, high connection setup and media delivery latency are becoming the critical issues to deploy the CDN-P2P system. These issues result from biased peer selection without location awareness and content awareness and lead to significant service disruption. To reduce service disruption latency, we propose a group-based CDN-P2P hybrid architecture (G-CP2P), which is a location/content-aware peer selection. Specifically, a SuperPeer performs a location-aware peer selection by employing a content addressable network (CAN) to distribute channel information. It also manages peers with content awareness, forming a group of peers with the same channel as the sub-overlay. Through the performance evaluation, we prove that the proposed architecture has better performance than the original CDNP2P hybrid architecture in terms of connection setup delay and media delivery time.

Mobility management based on proxy mobile IPv6 for multicasting services in home networks

Advances in broadband Internet access and enhanced performance of mobile devices have enabled seamless mobile IPTV service between indoor and outdoor. Mobile IPTV service is based on mobile multicasting to support efficient group communication. However, mobile multicasting has two constraints that we consider: a tunnel convergence problem and high handover latency. To reduce the two constraints, we propose a mobile multicasting model that is feasible for PMIPv6 domain. The proposed model removes tunnel convergence and reduces router processing. We then propose a fast handover scheme using a context transfer mechanism suitable for the proposed model. We also show that the proposed scheme outperforms previously proposed schemes in terms of packet delivery cost and handover latency.

Enhanced PMIPv6 Route Optimization Handover

Packet delivery in Proxy Mobile IPv6 (PMIPv6) relies on an anchor node called LMA. All packets sent by a source node reach a receiver node via LMA, even though the two nodes attach to the same MAG. In some scenarios, PMIPv6 results in high delivery latency and processing costs due to this unnecessary detour. To address this issue, several PMIPv6 route optimization schemes have been proposed. However, high signaling costs and excessive delays remain when handover is performed. For this reason, we propose an enhanced PMIPv6 route optimization (EPRO) scheme. In addition, we analyze the performance of the EPRO. Analytical results indicate that the EPRO outperforms previous schemes in terms of signaling overhead and handover latency.

Adaptive Handoff Management in the Proxy Mobile IPv6 Domain

To improve handoff performance of the network-based Proxy Mobile IPv6 (PMIPv6), two types of enhanced handoff schemes have been presented; fast handover for PMIPv6 (F-PMIPv6) and route optimization handover (ROH). The F-PMIPv6 is committed to reduce handoff latency and is efficient to perform handoff signaling. However, it causes high packet delivery cost from additional tunneling at the LMA. The ROH minimizes packet delivery cost by allowing direct route of MAG-to-MAG but introduces high handoff signaling cost. Due to the tradeoff between handoff signaling and packet delivery cost, both schemes cannot guarantee a better performance for a diverse mobile environment where a mobile node (MN) has a different session arrival and mobility rate. Thus, we propose an adaptive PMIPv6 handoff (APHO) scheme to reduce the overall data overhead and improve the throughput over a wide range of session-to-mobility ratio (SMR). The APHO consists of mobility-aware APHO (M-APHO) and session-aware S-APHO (S-APHO), which are determined by comparing the SMR and pre-defined threshold. By analyzing the performance of FHO, ROH, and APHO, we confirm that the APHO has a better performance than the other schemes over a wide range of SMR.

A design of M2M-based intelligent operating system for effective pollution control facilities

This paper presents a design of intelligent operating system for effective pollution control facilities by utilizing IT-based machine-to-machine (M2M) converged technology. By comparing proposed system with conventional system, we describe the benefits of proposed system in terms of flexible capacity, operation, cost, and performance efficiency.

Proxy-Based Energy Efficient Peer-to-Peer Push-to-Talk Service Mechanism for Ad-Hoc Networks

Push-to-talk (PTT) is a promising service for groupbased voice communication in ad-hoc networks that organize communication groups. Previously proposed iPTT mechanisms use a cluster-based super node for call determination. However, a hierarchical structure that uses clusters introduces unnecessary signaling costs, while an ad hoc network is vulnerable to energy consumption. To solve these challenges, this paper proposes a proxy-based energy efficient peer-to-peer push-to-talk (ePTT) service mechanism for ad-hoc networks. Through analysis of the performance of two schemes, we confirmed that the proposed ePTT is superior to iPTT in terms of signaling costs for overlay network construction and call determination.

WiMAX multicast/broadcast services support in home environments

Multicast/broadcast service (MCBCS) is one of the most advanced services of all wireless network standards. Recently, the WiMAX forum introduced MCBCS with three different types of internal data paths that differentiate the ways in which MCBCS data are packaged and delivered. In order to extend WiMAX access to the indoor users in home environment, femtocell technology has been considered. However, an application and evaluation of MCBCS structures over the WiMAX femtocell system have not been studied yet. In this paper, we therefore classify the applicable MCBCS network model for home users in femtocell systems and evaluate the performance of each model in terms of transmission overhead and buffer size required in data packaging. From the results, we note that the separated femto model using type-3 and type-4 data paths has more transmission overhead and requires more buffers than type-1, but these are reduced when the error rate decreases between the femto gateway (Fe-GW) and the WiMAX femto access point (WFAP). Moreover, we confirm that there are no differences in performance among types of model in the combined femto model.

Comparison of multicast/broadcast service architectures in mobile WiMAX networks

This paper compares and analyzes the data delivery mechanisms of the type-1 and the type-3 architectures, which have different ways of packaging and delivering data, introduced by the WiMAX forum for WiMAX multicast/ broadcast service.

ISP-Driven Managed P2P Framework for Effective Real-Time IPTV Service

Over the years, in attempts to overcome client-server based limitations, a variety of Peer-to-Peer (P2P) technologies have been developed. This feature can contribute to robustness and scalability. However, it introduces network-oblivious traffic because of network-unaware peer selection. As P2P users have increased, so does the damage this problem causes. To solve this problem, various P2P model based on collaboration between ISP and P2P users have been recently suggested and then reduced network-oblivious traffic by removing biased peer selection. However, previous schemes have mainly focused on reducing traffic, which does improve network performance. In order to support effective real-time IPTV services, it should be required to not only reduce network-oblivious traffic, but it should also improve user performance such as delay and jitter because IPTV is an application sensitive to delay and jitter. In fact, the reduction of network-oblivious traffic improves user performance but it cannot always guarantee optimum performance experienced by real-time streaming service users. In this paper, we propose an ISP-driven managed P2P framework and peer selection mechanism for real-time IPTV user. For the evaluation, we use a QualNet 4.0 simulator and show proposed mechanism provides the performance effectively. Ultimately, we confirmed that ISPs should reflect the delay information of organized P2P network as well as the link traffic between each peer for effective real-time IPTV services.