Hyon Young Choi

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.

Implementation and Evaluation of Proxy Mobile IPv6 in NS-3 Network Simulator

With the rapid growth in the number of mobile subscribers and mobile devices, the demand high-speed Internet access is becoming a primary concern in our lives. Not long ago, the most stable and well known solution of IP-based mobility management is Mobile IPv6 (MIPv6). Even if MIPv6 is a well-known mature standard for IPv6 mobility management support, however, it has revealed some problems such as handover latency, packet loss, and signaling overhead. Thus, a new IPv6 mobility management protocol called Proxy Mobile IPv6 (PMIPv6) is being actively standardized by the IETF NETLMM Working Group. Unlike the various host-based protocols such as MIPv6, a network-based approach such as PMIPv6 has salient features and is expected to expedite the real deployment of IP-based mobility management. In this paper, we present an implementation of PMIPv6 in NS-3 network simulator and the evaluation of the simulation for validating.

PMIPv6-based Flow Mobility Simulation in NS-3

Proxy Mobile IPv6 (PMIPv6) is a network-based mobility support protocol and it does not require MNs to be involved in the mobility support signaling. In flow mobility support, although the virtual interface in the MN solved the problems of vertical handover or flow mobility in heterogeneous network, missing procedure of MN-derived flow handover makes flow mobility in PMIPv6 incomplete. In this paper, enhanced flow mobility support is proposed for actualizing and full-covering of the flow mobility support in PMIPv6. Enhanced flow mobility support is based on a virtual interface in the MN. Virtual interface makes all physical interfaces to hide from the network layer and above. Flow Interface Manager is placed at the virtual interface and Flow Binding Manager in the LMA is paired with Flow Interface Manager. They manage the flow bindings and are used to select proper access technology to send packets. Flow mobility procedure begins with three different triggering cases, which are caused by new connection from the MN, the LMAs decision, and request from the MN, respectively. Simulation using NS-3 network simulator is performed to provide clear and practical procedure of enhanced flow mobility support in PMIPv6.

Smart Buffering for seamless handover in Proxy Mobile IPv6

Proxy Mobile IPv6 (PMIPv6) is proposed as a new network-based mobility protocol and it does not require MNs involving in mobility management. MN can handover relatively faster in PMIPv6 than in Mobile IPv6 (MIPv6) because it actively uses link-layer attachment information and reduces the movement detection time, and eliminates duplicate address detection procedure. However, the current PMIPv6 cannot prevent packet loss during the handover period. We propose the Smart Buffering scheme for seamlessness in PMIPv6. The Smart Buffering scheme prevents packet loss by proactively buffering packets that will be lost in a current serving mobile access gateway (MAG) by harnessing network-side information only. It also performs redundant packet elimination and packet reordering to minimize duplicate packet delivery and disruption of connection-oriented flows. To fetch buffered packets from a previous MAG, a new MAG discovers the previous MAG by using a discovery mechanism without any involvement of an MN. We verified the effectiveness of Smart Buffering via simulation with various parameters. Copyright

Seamless handover scheme for proxy mobile IPv6 using smart buffering

PMIPv6 is proposed as a new network-based mobility protocol and it does not require MNs involving in mobility signaling. PMIPv6 can handover relatively faster than MIPv6 because of using link layer attachment information and micro mobility characteristic. However, current PMIPv6 cannot prevent packet loss in disruption period. We proposed in this paper, Smart Buffering scheme for supporting seamless handover in PMIPv6. Smart Buffering scheme prevents packet loss totally by buffering lost candidate packets in a current serving MAG and forwarding it to a new MAG, after an MN successfully connected. Smart Buffering also performs redundant packet removing in a previous MAG and packet reordering in a new MAG to maximize performance of seamless handover. All these procedures between a previous MAG and a new MAG are processed using simple message exchanges without requiring any involving of an MN. We verified the effectiveness of the Smart Buffering by simulation with various parameters. Simulation results prove that proposed scheme prevent packet loss in the handover and handle buffered packets very efficiently. As a result, we conclude that Smart Buffering is very useful for supporting seamless handover in PMIPv6.

Reactive Smart Buffering Scheme for Seamless Handover in PMIPv6

PMIPv6 is proposed as a new network-based local mobility management. Even if PMIPv6 exploits the locality of Mobile Nodes (MNs) at the mobility management, it still has the packet loss problem during the handover period like MIPv6. We propose a new reactive network-based scheme for seamless handover in PMIPv6. The scheme prevents packet loss during the handover period by buffering packets which are expected to be lost by MNs movement. All decisions related with early packet buffering are made at the access routers without any MNs involvement.

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.

A Route Optimization Scheme Based on Roaming in PMIPv6 (pROR)

In PMIPv6, We propose a new Route Optimization (RO) scheme with roaming among the inter-domains. Previous works are used direct packet forwarding methods among the Mobile Access Gateways (MAGs) because the MAG manages the signaling for the mobile nodes (MNs) to support the mobility. However, previous works cause a lot of problems in security, packet delivery latency, and increasing the control messages. For this reason, we propose bi-directional tunnel among the Local Mobility Anchors (LMAs) and MAGs to support the RO when the MN handovers to the other PMIPv6 domains. We prove the RO with LMAs is more efficient than the previous work. Moreover, we implement our RO scheme and compare it with the roaming scheme in PMIPv6.

RED-RT for Congestion Control and Real Time Traffic Protection

RED-RT is proposed to protect real time traffic from non real time traffic in routers. Active Queue Management (AQM) mechanisms in routers have been developed to prevent congestion and to improve the fairness between adaptive (TCP) traffic and non adaptive (UDP) traffic. But they do not consider the QoS requirements of flows. Real time traffic is usually transported via RTP over UDP. UDP traffic is not protected from dropping and even discriminated against TCP traffic. As a result, for real time traffic protection scheduling mechanisms are normally used. However, AQM can roughly satisfy the QoS requirements of real time traffic by classification of traffic into real time flows and non real time flows and by applying different policy to them. The proposed RED-RT does not drop real time traffic during non congested periods and applies a lower drop rate for real time traffic than that of non real time traffic during congested periods in a router. The simulation result shows that RED-RT can roughly satisfy the QoS requirements for bandwidth, drop rate, and delay for real time traffic. This means that RED-RT can be used as congestion control and preliminary substitution for scheduling mechanism for real time traffic.

Power-Aware Data Transmission for Real-Time Communication in Multimedia Sensor Networks

The availability of smart sensors equipped CMOS cameras made it possible to capture and transmit multimedia data ubiquitously. The real-time performance is essential in many applications including surveillance and healthcare monitoring in multimedia sensor networks (MSNs). One of the real-time performance indicators is to transmit the packets within their deadline. Furthermore, in information-rich, battery-powered, and resource-constrained MSNs, it is a challenging problem to extend network lifetime decreasing communication cost. In previous researches, periodic message exchange for neighbor information maintenance leads to reducing network lifetime. This paper presents a power-aware data transmission for real-time communication in MSNs. The proposed scheme not only provides real-time performance, but also conserves energy consumption through efficient transmission and without periodic message exchange. The simulation results show the effectiveness of the proposed scheme in achieving the desired deadline success ratio and prolonging the network lifetime.