Dong Phil Kim

Analysis of Handover Latency for Mobile IPv6 and mSCTP

This paper analyzes the handover latency of mobile IP and mobile SCTP over IPv6 networks. The analytical results are compared with performance by experiment over Linux testbed. For the analysis, we consider the two handover scenarios: horizontal handover and vertical handover. From the results, we see that the mSCTP handover can provide smaller handover latency than the Mobile IP. Moreover, the mSCTP can give much smaller handover latency for the vertical handover where has enough sojourn time of MN in the overlapping region between different subnet regions, compared to the horizontal handover.

On the Packet Reordering of mSCTP for Vertical Handover in Heterogneous Wireless Networks

This paper deals with the packet reordering problem of the mobile stream control transmission protocol (mSCTP) for vertical handover in heterogeneous wireless networks, in which might occur due to the discrepancy of link bandwidth and transmission delay when MN switches its primary path into a new path with different characteristics such as link bandwidth and transmission delay. This packet reordering problem tends to induce spurious fast retransmissions and unnecessary reduction of the congestion window in the mSCTP vertical handover. To solve this problem, we propose a simple and novel scheme in which the correspondent node (CN) will retransmit the outstanding data chunks just before transmission of the newly generated data chunks over the new primary address. From the simulation results, we can see the proposed scheme could significantly improve the transmission performance during handover, compared with the existing mSCTP handover scheme, by avoiding spurious fast retransmission and unnecessary reduction of the congestion window.

Analysis of SCTP handover by movement patterns

Stream Control Transmission Protocol (SCTP) is a new end-to-end transport protocol, which can be used to support the mobility of mobile terminals. This paper describes a framework of SCTP handover and analyzes the handover latency for the single-homing mobile terminals. We then show the experimental results of the SCTP handover in terms of the handover latency and throughput for the two different movement patterns: linear and crossover patterns. For the linear movement pattern, it is shown that the SCTP handover latency may severely depend on the handover delay at the underlying link layer. In the case of the crossover movement pattern, we see that the throughput of the data transmission could be degraded, as the crossover movements occur more frequently.

Adaptive Primary Path Switching for SCTP Handover

This paper proposes a primary path switching scheme for SCTP handover, in which a mobile terminal switches its primary path to an alternate path adaptively by using the round trip times (RTTs) of the paths measured in the network. From the experiments we see that a conservative switching scheme is preferred in the network where the gap of RTTs of the candidate paths is small, whereas an aggressive scheme is reasonable in the network with a large gap of RTTs.

mSCTP-DAC: dynamic address configuration for mSCTP handover

This paper proposes a dynamic IP address configuration (DAC) scheme for mSCTP handover, which exploits the information from the link layer to support SCTP handover between heterogeneous access networks. The proposed DAC scheme enables a mobile terminal to automatically add a new IP address in the newly visited region, change the primary path, and delete the old IP address so as to support the mSCTP handover. For experimental analysis of mSCTP handover, we consider the handover scenarios for 3G-BWA and 3G-WLAN over Linux platforms. From experimental results, it is shown that the throughput and handover latency of the mSCTP handover would be affected by the timing of primary-change and the overlapping period

Adaptive Congestion Control of mSCTP for Vertical Handover Based on Bandwidth Estimation in Heterogeneous Wireless Networks

This paper proposes a new congestion control scheme of mobile Stream Control Transmission Protocol (mSCTP) for vertical handover across heterogeneous wireless/mobile networks. The proposed scheme is based on the estimation of available bandwidths in the underlying network as a cross-layer optimization approach. For congestion control of mSCTP, the initial congestion window size of the new primary path is adaptively configured, depending on the available bandwidth of the new link that a mobile node moves into. By ns-2 simulation, the proposed scheme is compared with the existing congestion control schemes in the throughput perspective. From the numerical results, we can see that the proposed mSCTP congestion control scheme could give better performance than the existing schemes in the wireless networks with an amount of background traffic.

Use of SCTP for IP handover support

This paper describes the experimental analysis of SCTP handover for the dual-homing and single-homing mobile terminals based on Linux platform. From the experiments, it is shown that the SCTP handover latency of the dual-homing mobile terminal only depends on the round trip time between two SCTP endpoints, possibly with a negligible latency time. On the other hand delay of the underlying link and network layer.

An integrated scheme for intrusion detection in WLAN

Wireless Local Area Network (WLAN) is susceptible to security provisioning in spite of the solutions such as the Wired Equivalent Protocol (WEP) or IEEE 802.1x This paper proposes an integrated scheme for intrusion detection in WLAN systems The proposed scheme operates with one or more Gathering Agents (GAs) and a Master Server (MS) Each GA is used to get security information by collecting the frame packets in WLAN, whereas the MS is purposed to detect and prevent the various attacks by analyzing the packets in the WLAN systems A detection engine contained in the MS employs OUI list matching for detection of MAC spoofing attacks, sequence number analysis for man-in-the-middle attacks, and Finite State Machine (FSM) analysis for Denial-of-Service (DoS) attacks By experiments, it is shown that the proposed scheme could effectively detect and prevent the various attacks that could possibly be done in the WLAN systems.