Hewei Yu

Initiative movement prediction assisted adaptive handover trigger scheme in fast MIPv6

Roaming across two adjacent access networks poses a challenging issue in providing continuity services for end-users. FMIPv6, a cross layer handover scheme proposed by the IETF, requires the timely link layer (L2) trigger to invoke the handover protocols of upper layer, the specified handover procedures hence can be completed before terminating the current wireless link. Generating the L2 trigger however is not always preferable by experimental analysis. The premature L2 trigger leads to a false alarm and unnecessary handover operations with serious performance loss and resources waste. By analyzing the movement behavior of the mobile node (MN), an initiative movement predictive algorithm is developed to predict the movement trend of the MN, and an adaptive handover trigger scheme (IMP-AHT) taken as the supplement for FMIPv6 is proposed accordingly. IMP-AHT addresses the investigation on rational decision of generating L2 trigger reliably. Owing to the inevitably introduced errors of the prediction process, some effective measures are also introduced to compensate the degraded performance caused by the false decisions. Simulations will compare as well as analyze IMP-AHT and FMIPv6 to evaluate the efficiency.

Fast Handover in Hierarchical Mobile IPv6 Based on Motion Pattern Detection of Mobile Node

To meet the increasing communication requirement for people in ubiquitous environments, some handover schemes and improvements were proposed by the IETF in order to support mobility effectively. FHMIPv6 combines the advantages of FMIPv6 and HMIPv6. This paper proposes an improved scheme based on FHMIPv6 which mainly implements a combined-detection function between Mobile Node (MN) and Mobility Anchor Point (MAP) and calculates the Normalized Edit Distance to analyze the motion trail and estimate the motion pattern of MN. According to the estimating result, MAP determines the way MN attaches to the new access point so as to reuse some previous handover information and intellectualize the handover process to avoid redundant binding updating. Simulation results based on Network Simulation 2 (NS2) show that this improved scheme can reduce the packet’s loss rate and handover latency, enhance the throughput and improve the network performance as a whole, especially for MN with the Ping-Pong motion pattern.

A smart Android based remote monitoring system

This paper proposes a smart, easy-deployed remote monitor system based on Android system. Different from normal monitor system, what you need to deploy the monitor system are only a camera, a PC with Linux system and an Android smart phone, which is commonly held by people. The system is based on the open-source library live555, FFmpeg and x264, thus it is readily extendable. In this system, the video is recorded using V4L2 interface and encoded by x264. The live555 media server then forwards the video stream over RTSP to the client. Finally, the client decodes the video and plays it. Performance test shows that this system has the basic function of remote video recorder and can work smoothly.

Improving QoE Using a Novel Multipath Routing Based on Source and Intermediate Node Forwarding

This paper proposes a simple and effective algorithm to improve the quality of service on the Internet by providing alternate path between source and destination nodes when the delay or packet loss rate on the primary path becomes unacceptable. We combine Source Routing with an Intermediate Node forwarding mechanism to yield a multipath routing mechanism called SIR (Source Intermediate Routing). It includes a simple algorithm to place the intermediate nodes so that the alternate paths have as few common links and nodes as possible. Simulation shows SIR can reduce the probability of path congestion when some links are congested and provide an adequate quality of service.

Testing for handover performance based on Android Intelligent Mobile Equipment

This paper reviewed the research on mobile IP technologies for improving handover performance. After making comparison between different test methods used in those researches, the Testing for Handover Performance based on Android Intelligent Mobile Equipment (THPAIME) is proposed. Based on the open-source project OAI PMIPv6, the platform for testing Proxy Mobile IPv6 (PMIPv6) is constructed. In our test, the program for sending data packets is running on personal computer and that of receiving data packets is running on Android intelligent mobile equipment. In fact, PC and Android smartphone serve as correspondent node (CN) and mobile node (MN) respectively. Test data collected by Android smartphone can be illustrated on the screen. Experiment results show that the scheme is superior to conventional methods in terms of complexity and operability.

A Novel Multimedia Player Based on Embedded System

This paper proposed a novel multimedia player based on embedded system. Different from normal player, it decodes the audio-video stream using a multithreaded mechanism based timeline, and does not need the traditional driving library for playing media — FFMPEG. The player decides the IDR frame for every group of audio-video stream at first, then plays stream according to the interactive model of audio and video. It makes the best use of decoding acceleration engine of embedded chip, has higher decoding efficiency, and saves a lot of resource for embedded system.

Audio-Video Synchronization Method Based on Playback Time

This paper proposes an audio and video synchronization method based on playback time. In ordinary playing process, the playback rate of audio is constant, so we can locate the playback time of audio and video by locating the key frame to get synchronization. Experimental results show that this method can get synchronization between audio and video and be achieved simply, furthermore, it can reduce the system overhead for synchronization.

Research of Fast Handover Technique of Mobile IPv6

This paper proposes an improved scheme of FHMIPv6 (Fast Handover for Hierarchical Mobile IPv6). Using buffer tables to store the information of CoA (Care of Address) and tunnel between MN (Mobile Node) and MAP (Mobile Anchor Point), when MN returns to PAR (Previous Access Router) in a certain period of time, the system would directly use the information in the related buffer records to complete the handover and skip the steps of configuring CoA and establishing tunnel, so MN can rapidly connect to the access router, thus reducing the handover latency.

An Improved Mobile IP Scheme Based on MobiCast

MobiCast is a mobile IP multicast algorithm which is used in the scene of small-scale wireless beehive network, it ensures the lowest packet’s lost rate when mobile node handovers in the same domain after introducing the concept of domain and Domain Foreign Agent (DFA). Based on MobiCast, An improved scheme is proposed in this paper which introduces “Tunnel-scheme” between DFA(s) in neighboring domains, and new DFA registers to the Multicast Group in advance. Moreover, the ware of conform packets is introduced to resolve out of order and reconstruction of Multicast packets. Simulation results based on Network Simulator Version 2 show that the improved scheme can reduce the packet’s lost rate, the whole handover delay in maximum and enhance the throughput, thereby, it can improve the performance and quality of service of the network as a whole when mobile node handovers between neighboring domains.