Jinwoo Park

Software defined service migration through legacy service integration into 4G networks and future evolutions

With the ongoing worldwide deployment of 4G networks and consequent drop of the utilization ratio of legacy networks, network operators need a cost-effective way to flexibly operate and manage networks. The obligatory continuation of legacy services in their respective legacy networks consistently incurs OPEX. In this situation, we argue that network operators can benefit from the recent advances in SDN and NFV. This article introduces a blueprint for designing a novel network architecture that integrates legacy network services into 4G networks through SDN/NFVs software-based characteristics. In addition, our architecture reduces time to market for employing newly emerging services without mandating any changes in 4G infrastructures.

Mobile flow-aware networks for mobility and QoS support in the IP-based wireless networks

AbstractnAs the volume of mobile traffic consisting of video, voice, and data is rapidly expanding, a challenge remains with the mobile transport network, which must deliver data traffic to mobile devices without degrading the service quality. Since every Internet service holds its own service quality requirements, the flow-aware traffic management in fine granularity has been widely investigated to guarantee Quality of Service (QoS) in the IP networks. However, the mobile flow-aware management has not been sufficiently developed yet because of the inherent constraints of flow routing in the mobile networks regarding flow-aware mobility and QoS support. In this paper, we propose a flow-aware mobility and QoS support scheme called mobile flow-aware network (MFAN) for IP-based wireless mobile networks. The proposed scheme consists of dynamic handoff mechanisms based on QoS requirements per flow to reduce the processing overhead of the flow router while ensuring QoS guarantee to mobile flows. The performance analyses of the proposed scheme demonstrate that MFAN successfully supports the mobile flow traffic delivery while satisfying the QoS requirement of flows in the wireless mobile IP networks.

WDM/SCM MAC protocol suitable for passive double star optical networks

A new WDM/SCM access protocol with node-grouping scheme suitable for passive double star packet networks is proposed. Combining SCM with WDM enables us to place control and data channels on the same wavelength resulting in large bandwidth and high data rate transmission. In the proposed protocol, packet delay is reduced in a large scale because the parts of access control should be done for the number of groups rather than the number of network nodes. Furthermore, additional reduction of the packet delay is achieved by limiting the propagation paths of control packets to the roundtrip between source nodes and sub-hub based on double star network configuration.

QoS-aware dynamic resource allocation for wireless broadband access networks

The development of the advanced wireless access technologies is focusing on the enhancement of mobile user satisfaction in terms of quality of service (QoS). As the number of mobile users increases, the amount of traffic passing through base station (BS) significantly increases so that the preplanned capacity of downlink or uplink can be exceeded from time to time resulting in the degradation of users’ QoS satisfaction. A way to utilize the downlink (DL) and the uplink (UL) of an orthogonal frequency division multiple access frame efficiently is therefore needed subject to users’ bandwidth demand which changes continuously over the time. In this paper, we propose a QoS-aware dynamic resource allocation (QDRA) scheme which dynamically adjusts the DL/UL ratio to allocate bandwidth for QoS support to users based on the usage statistics. The performance of the proposed QDRA scheme was examined by applying to the WiMAX standard specifications, to show its superiority of maintaining a higher QoS support for various classes of services compared to the pre-reported adaptive method.

Design and evaluation of survivable WDM networks by joint optimization method

Routing and planning of working capacity and spare capacity in WDM networks were investigated. Joint optimization technique has been used and the problem has been formulated to restore the general failure scenarios. The difference between the cost for the restoration of one node failure and the cost for the restoration of one link failure is decreased as more wavelengths per fiber are used. The difference between the cost of virtual wavelength path (VWP) network and the cost of wavelength path (WP) network is increased as more wavelengths per fiber are used.

WDM network design with waveband and wavelength multiplexing scheme

A network design method employing a two-stage multiplexing scheme which exploits the merits of wavelength granularity is presented for wavelength division multiplexing mesh networks. The effects of wavelength granularity and average demand on the crossconnect requirements and wavelength requirements are discussed.

Real-time white spectrum recognition for cognitive radio networks over TV white spaces

A key technical challenge in TV white spaces is the efficient spectrum usage without interfering with primary users. This paper considers available spectrum discovery scheme using in-band sensing signal to support super Wi-Fi services effectively. The proposed scheme in this paper adopts non-contiguous orthogonal frequency-division multiplexing (NC-OFDM) to utilize the fragmented channel in TV white space due to microphones while this channel cannot be used in IEEE 802.11af. The proposed solution is a novel available spectrum discovery scheme by exploiting the advantages of a sensing signaling. The proposed method achieves considerable improvement in throughput and delay time. The proposed method can use more subcarriers for transmission by applying NC-OFDM in contrast with the conventional IEEE 802.11af standard. Moreover, the increased number of wireless microphones (WMs) hardly affects the throughput of the proposed method because our proposal only excludes some subcarriers used by WMs. Additionally, the proposed method can cut discovery time down to under 10 ms because it can find available channels in real time by exchanging sensing signal without interference to the WM.

SDN/NFV-based scalable mobile service integration for gradual network evolution

The coexistence of heterogeneous networks is becoming increasingly more common with the evolution towards 5G, increasing the complexity and cost of deploying and managing these networks. Network operators consequently need to find efficient ways of flexibly constructing and operating networks within a heterogeneous network environment in order to reduce operational expenditure (OPEX) and capital expenditure (CAPEX). One possible way to meet this requirement is the accommodation of previous legacy network services in the newly-deployed network while gradually reducing the reliance on physical legacy networks. Software-defined transitional network (SDTN) architecture is a strong candidate to achieve this. In the SDTN, the software-defined networking and the networkf function virtualization (SDN/NFV) plays a key role in integrating legacy network services into the newly-deploying network. This paper proposes an SDTN architecture and presents an example of its deployment in a mobile network evolution scenario in which 3G mobile services are integrated into a 4G network. The unified mobility management, in which 3G mobile services are integrated into a 4G access networks based on SDN/NFV is described. The network nodes for legacy mobility management services are virtualized at the control plane and accommodated into the SDTN architecture. As a result, the mobility management is interoperable between the virtualized legacy network service functions and the underlying 4G network. In order to support various heterogeneous services integration into the 4G mobile network, scalable edge switches are proposed for protocol mapping between incoming heterogeneous service traffic and 4G data. The proposed SDTN approach can be applied to the future deployment of 5G networks by accommodating various pre-existing legacy services in newly-deploying networks.

P‐74: Synthesis and Characterizations of High‐Photosensitive Monomers for Black Matrix in Liquid Crystal Displays

Black matrix in liquid crystal displays plays important parts such as blocking the light leakage and enhancing the contrast ratio among the RGB pixels. In this paper, the authors describe new multi-functional monomers that may be used in black matrix to enhance the sensitivity of photo-resist.

QoS Provisioning Based on Flow-State Routing for Proxy Mobile IP

In the next-generation mobile wireless networks, mobility support and QoS provisioning are two critical issues. When it becomes much easier to access the internet from mobile devices, the real-time service over mobile network will be on high demand. To satisfy these requirements we must consider finest level of QoS guarantee in the mobile network. In this paper, we propose a QoS Provisioning Method based on flow-state routing for Proxy Mobile IP. We present the network-based mobility support and QoS provisioning.