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.

Dynamic point selection for LTE-advanced: Algorithms and performance

Abstract: Dynamic Point selection (DPS) is a key Downlink (DL) Coordinated Multipoint (CoMP) technique that switches the serving data Transmission Point (TP) of a User Equipment (UE) dynamically among the UE's cooperating set of TPs without requiring a cell handover. It provides performance improvement due to TP selection-diversity gains and dynamic UE load balancing benefit. In this paper, we propose two simple DPS schemes that take into account the UE's current channel conditions and the cell loading conditions to make the UE's TP switching decisions. We show that these schemes improve the system performance under different practical and realistic settings, such as, cell handover margin, TP switching periods, bursty traffic conditions, and cooperation cell cluster sizes.

Handover management in high-dense femtocellular networks

Abstract: Femtocell technology is envisioned to be widely deployed in subscribers’ homes to provide high data rate communications with quality of service. Dense deployment of femtocells will offload large amounts of traffic from the macrocellular network to the femtocellular network by the successful integration of macrocellular and femtocellular networks. Efficient handling of handover calls is the key for successful femtocell/macrocell integration. For dense femtocells, intelligent integrated femtocell/macrocell network architecture, a neighbor cell list with a minimum number of femtocells, effective call admission control (CAC), and handover processes with proper signaling are the open research issues. An appropriate traffic model for the integrated femtocell/macrocell network is also not yet developed. In this article, we present the major issues of mobility management for the integrated femtocell/macrocell network. We propose a novel algorithm to create a neighbor cell list with a minimum, but appropriate, number of cells for handover. We also propose detailed handover procedures and a novel traffic model for the integrated femtocell/macrocell network. The proposed CAC effectively handles various calls. The numerical and simulation results show the importance of the integrated femtocell/macrocell network and the performance improvement of the proposed schemes. Our proposed schemes for dense femtocells will be very effective for those in research and industry to implement.

Determining a reference power level for diversity handover base stations

Abstract: To combat base station power drift, the power transmission level of each base station in a diversity handover may be compared to a power reference established for all base stations in the diversity handover. The difference between the transmit power of each base station and the reference power threshold may then be used to correct the transmit power level of that base station. Because the power correction depends on the difference between the actual transmit power at the base station and the common power level reference, the various transmit powers of the different base stations in the diversity handover converge relatively quickly. Thus, even if the transmit power command from the mobile station is received in error in one or more of the base stations, the power correction based on the comparison to the common power reference compensates for such errors to reduce base station drift, obtain full diversity gain, and reduce unnecessary downlink interference. The reference power level(s) used in compensating for base station power drift is(are) advantageously determined using one or more parameters relevant to the current condition of the diversity handover communication. Rather than setting an arbitrary and static reference power level, the reference power level is set dynamically so that it is relevant to the current conditions of the diversity handover communication. Dynamic and adaptive reference power level setting results in more effective and more efficient downlink power control. Unnecessary power changes, both in frequency and in size, are avoided because the reference power level is more accurately determined for the current circumstances.

Distributed switching and control with fast resource assignment/handoff for personal communications systems

Abstract: An architecture for a combined personal, mobile, and (possibly) loop access microcellular communications system in which calls are digitized and packetized is presented. A network of microcells is utilized to communicate with the various subscribers via radio. A fast handoff/resource assignment process is introduced. It is subscriber-controlled and is jointly performed by the subscribers and base station employing the resource auction multiple access (RAMA) algorithm. In this deterministic algorithm, resource utilization is independent of traffic load. Using selected GSM parameters with RAMA, for the purpose of illustration, it is shown that, in microcells with delays of 1 mu s, 1080 resource assignments per second are feasible: and with delays as high as 45 mu s, 216 assignments per second are feasible. >