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.

Handover execution and communication resumption in wireless access system

Abstract: Handover execution and communication resumption in a wireless access system is provided. Performing a handover includes communicating with a serving base station through a first communication link and receiving from the serving base station, handover information associated with at least one candidate target base station. The method also includes transmitting handover indicator to the serving base station indicating a handover operation to a selected target base station and performing a ranging procedure with the selected target base station to establish a second communication link with the selected target base station while maintaining the first communication link with the serving base station. The method also includes being released from the serving base station in response to a handover complete status message from the selected target base station to the serving base station, or resuming normal communication with the serving base station if the handover fails with the selected target base station.

Handover in VLC systems with cooperating mobile devices

Abstract: Visible Light Communications (VLC) is emerging as viable means to overcome the crowded radio spectrum for highly-localized communications systems With such an approach, luminaires can be adopted for supporting data communication in addition to illumination in what we call Cellular Lighting However, in these systems, the directionality of light as the communication medium introduces new challenges in sustaining network connectivity especially under mobility scenarios In this paper we investigate mobility in VLC devices and propose an approach to managing handover adopted from wireless cellular systems, but with very small cells and directional characteristic Moreover, this technique provides the coordination and cooperation among VLC devices to achieve seamless connectivity in two different indoor scenarios consisting of overlapping (uniform lighting) and non-overlapping (spotlighting) cases Results indicate how different design decisions in supporting luminaire placement achieve full coverage at varying data rates

Method And Arrangement In A Wireless Communication System

Abstract: The present invention relates to a method and a device for time synchronization of an RBS which has lost its GPS signal. The method in the time synchronization device comprises retrieving from the first radio base station a first timing advance value (710) used by the user equipment to adjust its transmission timing before the handover, and a measurement of a reception timing (720) of a random access preamble. The random access preamble is transmitted from the user equipment to the second radio base station during synchronization. The method also comprises retrieving (730) from the second radio base station a second timing advance value used by the user equipment to adjust its transmission timing after the handover, and determining (740) a time synchronization offset between the first and second radio base station based on the retrieved first timing advance value, the second timing advance value, and the measurement of the reception timing.

Reduction of Handover Latency Using MIH Services in MIPv6

Abstract: In this paper, we propose an enhanced handover mechanism with new additional primitives and parameters to the media independent handover (MIH) services defined in the IEEE 802.21. The proposed scheme can reduce handover latency for mobile IPv6 (MIPv6) by removing the router discovery time. Moreover, when the proposed mechanism is applied to the FMIPv6, we can increase the probability that the FMIPv6 can be performed in predictive mode by reducing the handover initiation time, thereby we can reduce the expected handover latency in the FMIPv6. In addition, with the proposed scheme, we can design the network cost-effectively by reducing coverage overlap between adjacent cells because the handover initiation time in the FMIPv6 is decreased.

Mobile communication system with a load balancing feature

Abstract: A mobile communication system intended to control switching of a voice channel (handover) when a radio zone boundary is traversed; to quickly detect an unlawful mobile station; to equalize load if processing at a base control station is congested; and to constitute a location area for reducing control channel load due to simultaneous paging. The user is notified that a handover factor has been detected, and a switch enables the user's intention to be transmitted to the network to switch or stop the voice channel in accordance with the will of the mobile station user who is making the call. User accumulated call accounting information is totaled by the network and the mobile station individually for comparison to detect an unlawful mobile station. The number of base stations controlled by the base control station is, in real time, dynamically, changed to correspond to the state of congestion. Controls signals to the mobile stations are transmitted to a plurality of base control stations via a network of control lines. If the base control station detects process congestion, a portion of the controlled base stations is consigned to an adjacent base control station. The number of radio zones constituting the location area is, in real time, changed to correspond to the state of load for the call process to share load with the adjacent location area.