Papers by Keyword: Handoff

Abstract: For CBTC train-ground communication system, wireless interference is a matter of serious harm to the safety and reliability. This paper embarks from the on-board radio management module, designs the function of excluding wireless interference for radio management module.

Abstract: This paper introduces how the interworking happens between LTE with CDMA EVDO. It shows different kinds of behaviors during handoff between LTE and CDMA EVDO.

Abstract: We design a V2V-based fast handoff scheme using IP address passing for VANETs in this thesis. The proposed scheme allows a leaving vehicle in the exit area to pass an IP address which has been identified by the Duplicate Address Detection (DAD) procedure to the vehicles in the entry area directly. In addition, the leaving vehicle in the exit area can also pass an IP address to the vehicles in the middle area if there is no vehicles in the entry area. Therefore, our scheme can reduce the use of DHCP to obtain an IP address. Because DAD results in the largest delay of the whole DHCP procedure, our scheme can thus improve the utilization of IP address, reduce the time of acquiring an IP address, and reduce the whole handoff time.

Abstract: Quality of service (QoS) is so significant that it cannot be neglected in the recent evolution of wireless mobile networks, which are characterized by great heterogeneity. Handoff delay is one of the problematic issues that users are facing in the heterogeneous networks. In the wireless networks, many mobile users still cannot obtain the network resources they need when applying real-time services while handoff occurs. Consequently, providing a seamless handoff for QoS connections in heterogeneous wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) is crucial. In this paper, a resource ReSerVation Protocol (RSVP) extension scheme for seamless handoff in heterogeneous WLAN/WiMAX networks is proposed. The proposed scheme is based on QoS aware mobility architecture to guarantee a certain degree of QoS. The network selection is initiated by the mobility of the mobile station (MS) and pre-handoff is performed, basing on received signal strength (RSS). Simulation results show that the proposed scheme outperforms the previous schemes.

Abstract: In VANETs, each vehicle should obtain an IP address for its identification before connecting to the Internet or getting some information from the Internet. Due to the rapid movement of vehicles, each vehicle must perform a handoff procedure between different access points. To ensure that the transmission of packets is not interrupted, the handoff scheme for VANETs is a key design issue. In view of this, we design a V2V-based fast handoff scheme using IP address passing for VANETs in this thesis.

Abstract: The technology on network interconnection handoff with the QoS guarantee is becoming an important research issue in wireless mobile networks. Most of the current researches focus on the cell mobile networks, the schemes of which are comparatively complex in solving the QoS guarantee in mobile node handoff and the utilization rate of resource is lower. In order to reduce these disadvantages to the minimal extent, the model (HDBRA) on the mobile node handoff with service guarantee applied in the wireless mobile networks is presented in the paper based on the dynamic network bandwidth resource allocation in the real-time detection on the data flow state and network traffic-load in interconnection gateway nodes. And according to the state of the applications data in mobile node handoff, the model describes and analyzes in detail the dynamic resource allocation and reservation, and the release of the reserved resource as well. In the scheme, the real-time adjustment on resource allocation is achieved based on the real-time measurement on network traffic-load in interconnection gateway nodes and the method also achieves the balance on network traffic-load. Theoretic analysis and simulation test the correctness and validity of the model in the paper.

Abstract: The noise data results from two aspects, technically, different mobile phones traveling on different roads may generate the same handover sequence; operationally, signal error in mobile communication network possibly causes wrong handover information. Second, four types of noise data are summarized, that is wrong sample data from signal error, passenger cell phone sample noise data beside roads, vehicle cell phone sample ones between parallel and overlapping roads. Third, hierarchy and K means cluster algorithms are applied with SPSS software for the collected sample data cleaning based on real handover data by try and trial to produce link travel speed, which is compared with practical traffic situation. Finally, historic loop data is used as the baseline to evaluate the accuracy compared with cleaned results.

Abstract: In wireless network communication system, the complexity of communication system makes it difficult in experimental teaching and studying transmission interference. As collision probability is an important factor in transmission interference, the model to compute collision probability is very necessary. In this paper, an algorithm is proposed in computing collision probability based on handoff model. Then, a related hardware and software platform is established for analyzing transmission interference in high speed railway system. In simulation, it proves that collision probability can be decreased if the time of sending packet is changed.

Abstract: The duplicate address detection (DAD) has been a time-costly and a bottleneck in IP address configuration. The dynamic host configuration protocol (DHCP) was proposed and adopted to effectively assign unique address to a host. However, DHCP is not suitable for networks with a large number of nodes, and address renumbering under DHCP would be much more complicated than that under stateless auto-configuration. In vehicular networks, moving vehicles get connected to the Internet through the access point set up by the road. The handoff operation is supposed to happen frequently due to the fast moving of vehicles. Therefore, the performance of handoff becomes one of the most important issues to maintain seamlessly connection to the Internet in vehicular environment. In this paper, we propose a multi-hop group assisted handoff algorithm to effectively reduce handoff latency for avoiding the impact of time-consuming from IP configuration operation.

Abstract: To achieve the goal that anybody could communicate with anyone at anytime in anyplace and in anyway, many technologies, such as GSM、CDMA、WCDMA、CDMA2000、TD-SCDMA、802.11a/b/g and so on, come true in the past years. And now, many B3G or 4G technologies are being studied. It is well-known that the future network would be heterogeneous networks. It is studied in this paper the mobility management of wireless heterogeneous network and a reversing paging process of callee is proposed which integrates paging and handoff. In the process when the caller pages the callee choosing its best suited network on one end, the callee chooses its own best network to begin a reversing paging process to set up the communication. The simulation tells that the proposed process has better performances in the call delay, the call succeeding rate and the wireless signal cost than that of the existing process in which it sets up the call first and then does vertical handoff independently.