Seong Mun Kim

OpenFlow-based Proxy mobile IPv6 over software defined network (SDN)

Software Defined Network (SDN) is widely deployed by using OpenFlow protocol for the implementation of flexible networking. A lot of researches are progressing to adapt OpenFlow to existing network architectures. PMIPv6 is proposed to handle the network-based local mobility using IP tunneling. However, it has some weak points such as IP tunneling overhead and sharing same path for the data and the control planes. In this paper, we propose OpenFlow-based Proxy Mobile IPv6 (PMIPv6) to obtain the advantages of the OpenFlow architecture for PMIPv6 network. The proposed scheme separates the mobility management function from the components of PMIPv6. It preserves the functionalities and messages defined in PMIPv6 but reconstructs components to take the advantages offered by the OpenFlow architecture. The reconstructed components set the flow table of switches located in the path as the controller of OpenFlow. The proposed scheme removes the tunneling to forward user traffic and separates the data and the control planes. OpenFlow-based PMIPv6 offers more flexible deployment architecture.

A network-based host identifier locator separating protocol in software-defined networks

An IP address is used as a host identifier and a locator to bind hosts and applications to their location in existing Internet. Several protocols are proposed to eliminate this binding. Most of these protocols use IPv6-based host identifiers to maintain compatibility with existing Internet, but these identifiers cannot be handled by standard IPv6 routers because such identifiers are unroutable. Therefore, host identifiers need to be usually converted to locators at hosts, and the standard IPv6 protocol should be modified to interoperate with these protocols. In this paper, we propose a network-based host identifier locator separating scheme in software-defined network. The proposed scheme separates the underlying network into Host Identity and IP domains in order to directly forward unroutable identifiers. Host Identity domain includes its own routing strategy based on a distributed hash table algorithm. The proposed scheme directly handles the packets which have host identifiers as its addresses, and converts the host identifiers to the corresponding locators in the network. We compare the differences between the proposed scheme and other existing solutions.

Multiple Virtual Interfaces for Multi-homing Hosts to Support Inter-technology Handover in PMIPv6 Network

Proxy Mobile IPv6 (PMIPv6), a network-based mobility management protocol, supports multi-homing, inter-technology handover, and flow mobility, with the help of a host’s virtual interface (VI). Several single virtual interface (SVI) schemes have been proposed to support these functions. In the SVI schemes, the link-layer identifier (LL-ID) should be swapped while the host is processing neighbor discovery (ND) after inter-technology handover or flow mobility. That is, a host must replace the LL-ID of a VI contained in a neighbor advertisement with the LL-ID of a physical interface (PI) related to a real connection. Such LL-ID swapping cannot be executed under secure neighbor discovery, and it causes ND processing delay and high overhead to check all outgoing packets. In this paper, we propose a multiple virtual interfaces scheme to solve the problem related to the LL-ID swapping, and to provide good support to the inter-technology handover. In the proposed scheme, there are the same numbers of VIs as the PIs between the data link layer and the network layer of a host. Since each VI maintains its own neighbor cache, the proposed scheme does not require LL-ID swapping, so that it can keep the standard ND process. We explain the basic operation of PMIPv6 inter-technology handover under the proposed scheme and, through NS-3 simulation, evaluate the performance of the proposed scheme in terms of ND process delay and inter-technology handover latency.

OpenFlow-Based Mobility Management Scheme and Data Structure for the Mobility Service at Software Defined Networking

The network-based mobility management is adapted to the OpenFlow architecture for mobility service at Software Defined Networking (SDN), and data structure for mobility service is proposed. SDN is a newly proposed Internet architecture which decouples the data and control planes, and mobility management is one of the most important issues in SDN. In order to provide mobility management service by utilizing the mobility scheme proposed earlier in a new network environment, the existing mobility schemes need to be modified. Particularly, the characters of the network environment need to be considered when designing the function of the network entities and data structure. Our proposed mobility management scheme is focused on the centralized control mechanism of SDN. We referred to Proxy Mobile IPv6 (PMIPv6) and OpenFlow-based PMIPv6 with a centralized mobility management controller (OPMIPv6-C). It has a merged data structure for the mobility service on SDN controller and minimizes the number of switches which need flow table modification at handover. At the performance analysis chapter, we compare the signaling cost at the registration and handover phase, packet delivery cost, and handover latency between the proposed scheme and OPMIPv6-C.

The effective IVIS menu and control type of an instrumental gauge cluster and steering wheel remote control with a menu traversal

The present study investigated the effective IVIS menu and control type of the instrument gauge cluster and steering wheel remote control. Participants performed menu traversal tasks with a steering wheel remote control and gauge cluster display in a driving video simulation. Two steps of experiment were conducted. The first was focused on the menu type and within-subject factorial design was implemented with two levels of menu types (the spread and overlapped menu type), two levels of control types (the wheel and touch wheel controller) and two levels of menu traversal tasks. Subjective ratings of a preference (using modified Likert-type rating scale) and a menu traversal time and routing error were obtained as performance measures. ANOVA results showed that the menu type, control type and the interaction of the control and task were significantly affected by each of the independent variables. The result implied that the spread menu type and wheel controller were more effective. The second experiment was focused on the control type with the spread menu type and within-subject factorial design was implemented with two levels of control types (the wheel and 4-way directional controller) and two levels of menu traversal tasks. ANOVA results of a performance showed that the control type and task were significantly affected. The result implied that the wheel control type with the spread menu type was more effective IVIS interface alternative on a gauge cluster and steering wheel remote control.

BFD-based link latency measurement in software defined networking

5G networks offer various network services based on software defined networking and network function virtualization. However, certain services are sensitive to link latency which is why it is consistently observed to provide high quality services. Previous studies have proposed two approaches to this task: measuring the latency by probe packets and link-layer discovery protocol (LLDP) packets. However, they have several limitations like flow rule preconfiguration, influence of the control plane traffic, and necessity of calibration. In this paper, Bidirectional forwarding detection (BFD) based approach is proposed. The approach measures latency at the data plane with simply implemented echo mode in Open vSwitch. We evaluates and compare the proposed approach to LLDP-based one in terms of single link latency and path latency, and error rate. In addition, we verify that the control plane throughput affects link latency according to the increased number of switches. As a result, the proposed approach can resolve the limitations and provides accuracy link latency.

Effective quality factors of multimodal interaction in simple and complex tasks of using a smart television

Influencing quality factors, related to the user and system, need to be considered when building a well-designed multimodal interaction system. User groups, access to input modes and tasks were defined as the user and system factors to examine effective factors of multimodal interaction with a smart TV, and its input modes consisted of voice, arrow key, and motion-based pointer modes and their combinations. User group 1 had experience of multimodal interaction with another device, while user group 2 had only experience of unimodal interaction. In addition, the sequential/simultaneous input modes and simple/complex tasks were considered as the system factors. Depending on the task complexity, two experiments were conducted. Nine input modes (three unimodes and six multimodes), sequentially and simultaneously given to both user groups, were investigated for the simple task of menu traversal and the complex task of manipulating broadcasting content, menu traversal, and web content navigation. A subjective rating of the level of preference was recorded in the sequential input mode using a modified Likert-type rating scale, while each participant’s preferred mode was observed in the simultaneous scenario. Additionally, the completion time and error rate were measured in both experiments. When performing the simple task, user group 1 used multimodes more so than group 2. However, in the complex task, both user groups preferred multimodes when modes were simultaneously presented. Considering effective quality factors, input modes of a smart TV should be simultaneously provided with a voice and motion-based pointer multimode.

Micro mobility management for dual connectivity in LTE HetNets

A Dual Connectivity architecture has been proposed by 3GPP for enhancement of small cells in long term evolution heterogeneous networks. A Master eNodeB (MeNB) handles handovers on behalf of the Mobility Management Entity (MME) and the Serving Gateway (SGW) for secondary eNodeBs (SeNB) located within the coverage of MeNB. Workloads of the MME and the SGW are moved to the MeNB. Small cells can be concentrated in crowded downtown or buildings in the heterogeneous network environment. The number of handovers may be increased due to concentrated small cells having small coverage, so the workload of the MeNB can be increased inside the hot spot. We propose a micro mobility management scheme to offload the workload of the MeNB to other components. The proposed scheme introduces a mobility anchor (MA) which processes the handovers between SeNBs on behalf of MeNB. Simulation results indicate the reduction of the workload of the MeNB due to the MA.

Dynamic distributed PMIPv6 for distributed mobility management

Traditional mobility management architectures are a centralized structure which has several problems and limitations, such as a single point of failure, scalability problem, triangle routing, and tunneling overhead thereby node which is fixed or in idle mode. Distributed Mobility Management (DMM) focuses on solving those problems caused by centralized mobility management. There are several PMIP-based schemes for DMM proposed in IETF DMM WG. However, they do not satisfy all key requirements of DMM. In this paper, we propose a new DMM scheme, Dynamic Distributed PMIPv6 (DYD-PMIP), which satisfies all key requirements and additionally supports routing optimization with the help of new procedures and messages about ongoing sessions or new sessions. We compare with other DMM schemes based on PMIP.

Multiple virtual interfaces to support multi-homing hosts in PMIPv6 network

Proxy Mobile IPv6 (PMIPv6) is a network-based mobility management protocol. Mobile node (MN) does not participate in mobility-related signaling in PMIPv6. PMIPv6 can support multi-homing hosts with the help of virtual interface to perform inter-technology handover or to support flow mobility. However, a single virtual interface has the problem of swapping link-layer identifier (LL-ID) when the neighbor discovery is performed after inter-technology handover. Whenever the single virtual interface receives an Neighbor Solicitation (NS) message, the virtual interface analyzes the NS message and it changes the LL-ID of virtual interface to the LL-ID of physical interface for keeping communication. This approach is not natural and is not recommended because it has a security problem. In this paper, the efficient inter-technology handover scheme with the multiple virtual interfaces are proposed to solve the problem of swapping LL-ID with Proxy Neighbor Advertisement message in Neighbor Discovery. This paper explains the difference based on the result of comparison with a single virtual interface. NS-3 simulation is performed to provide a clear and practical procedure of multiple virtual interfaces in PMIPv6 network.