Handover

About: Handover is a research topic. Over the lifetime, 24219 publications have been published within this topic receiving 296416 citations. The topic is also known as: handoff.

Network Mobility Protocol for Vehicular Ad Hoc Networks

Abstract: The goal of the network mobility (NEMO) management is to effectively reduce the complexity of handoff procedure and keep the mobile devices connected to the Internet Vehicle is moving so fast that it may cause the handoff and packet loss problems Both of the problems will lower down the throughput of the network To overcome these problems, we propose a novel NEMO protocol for vehicular ad hoc network (VANET) In freeway, since every car is moving in a fixed direction with high moving speed, the car adopting our protocol can acquire IP address from the VANET through vehicle to vehicle communications The vehicle can rely on the assistance of the front vehicle to execute the pre-handoff procedure or it may acquire its new IP address through multi-hop relays from the car on the lanes of the same or opposite direction and thus reduces the handoff delay and maintain the connectivity to the Internet Simulation results have shown that the proposed scheme is able to reduce both handoff delay and packet loss rate

Seamless soft handoff in a CDMA cellular communications system

Abstract: During a 'make before you break' handoff performed within a CDMA communications system, duplicate downlink communications (50) are generated and routed through different base stations (16) for delivery to the mobile station (18). At the mobile station, the duplicate signals are received and the frame sequence numbers of the substantially simultaneously received frames (58) therein are compared (60). If the sequence numbers do not match, the duplicate signals are identified as not being synchronously received by the mobile station. In response thereto, the mobile station signals (64) the communications network on the uplink with a timing adjustment message, and appropriate timing modifications (66) are made with respect to the transmission of the duplicate signals in order to provide for substantially synchronous reception. Diversity combination and decoding (68) are then performed on the received signals. Alternatively, the mobile station buffers (72) the earlier arriving signal and waits for the later arrival of the sequence number matching frame of the duplicate signal before engaging in diversity combining and decoding of the received signals.

Handover method and apparatus in a mobile communication system

Abstract: A method and apparatus for minimizing data forwarding between Evolved Node Bs (ENBs) during a handover. A User Equipment (UE) sends a status report to an ENB of a source cell immediately before the handover occurs. In this manner, a target cell avoids retransmission of the RLC PDUs, which were successfully transmitted but have not yet been ACKnowledged (ACKed) by the UE, thereby minimizing the amount of data being forwarded from the ENB of the source cell to an ENB of the target cell.

Supporting IP/LEO satellite networks by handover-independent IP mobility management

Abstract: Low earth orbit (LEO) satellite networks are capable of providing wireless connectivity to any part of the world while guaranteeing short propagation delays. There is a huge need for developing Internet protocol (IP) friendly networking technologies that aim to integrate emerging LEO satellite networks with the already existing terrestrial IP networks. LEO satellite networks are well characterized by frequent handover occurrences. These handovers largely affect mobility management in LEO satellite networks. Existing IP mobility management protocols, such as mobile IP, manage the location of mobile nodes on the basis of the network topology. Applying such mechanisms in LEO satellite networks will cause a binding update of mobile nodes upon every handover occurrence. Given the frequent occurrence of handovers in LEO satellite networks, a potentially large number of binding update requests will be generated and ultimately affects the scalability of mobility management. This paper argues a handover-independent mobility management scheme for LEO satellite networks. The proposed scheme purposes to exploit geographical location information to make the mobility management independent from handovers. This handover-independent management method reduces the number of update requests and eventually increases the system scalability. A detailed description of the actual implementation of the scheme is given. Through a mathematical analysis, the paper evaluates the required management cost and accordingly verifies the scalability of the proposed scheme.

Network control for wireless communications

Abstract: Existing wireless network architectures and the increasing demand for cellular services are reviewed. Wireless network control tasks and the structure of a cellular packet switch (CPS) based on an optical fiber metropolitan area network (MAN) are described. Protocols for moving information through the MAN focusing on handoff, a crucial function of wireless networks, are discussed. The results of an analysis of switch performance as measured by capacity and the distribution of functionality are presented. Several open issues regarding the capability of the CPS to deliver telephone service to wireless terminals, including privacy and security issues, are discussed. >