Topic
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.
Papers published on a yearly basis
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19 Feb 1998
TL;DR: In this paper, a method and an apparatus is provided for acquiring satellite signals to establish the exact spatial position of a cellular radiotelephone, in order to perform a timely dropoff or smooth handoff to another base station or frequency.
Abstract: A method and an apparatus is provided for acquiring satellite signals to establish the exact spatial position of a cellular radiotelephone, in order to perform a timely dropoff or smooth handoff to another base station or frequency. The cellular radiotelephone is equipped with its own positioning system which uses satellite data to determine its spatial position. The communication system is preferably a Code Division Multiple Access (CDMA) system, and the positioning system is preferably a Global Positioning System (GPS). The method of the present invention may be used to determine the base station closest to the cellular radiotelephone. In the alternative, it may be used to compute a distance between the cellular radiotelephone and a location where the quality level of the cellular radiotelephone communication signal is predicted to be less than the predetermined value, and to determine from the computed distance whether the cellular radiotelephone should be handed off.
117 citations
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TL;DR: It is found that the proposed handoff algorithm performs well in a log-normal fading environment when the distance estimate error is modeled by wide-sense stationary additive white Gaussian noise.
Abstract: The performance of a proposed handoff algorithm based on both the distance of a mobile station to neighboring base stations and the relative signal strength measurements is evaluated. The algorithm performs handoff when the measured distance from the serving base station exceeds that from the candidate base station by a given threshold and if the measured signal strength of the adjacent base station exceeds that of the serving base station by a given hysteresis level. The average handoff delay and average number of handoffs are used as criteria for performance. Numerical results are presented to demonstrate the feasibility of the distance-based handoff algorithm, including results for an additional criterion based on relative signal strength. The proposed algorithm is compared with an algorithm based on absolute and relative signal strength measurements and with a solely distance-based algorithm. It is found that the proposed handoff algorithm performs well in a log-normal fading environment when the distance estimate error is modeled by wide-sense stationary additive white Gaussian noise.
117 citations
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22 Jun 1993TL;DR: In this paper, parallel physical links are formed between the mobile station (MS) and two or more base stations (BTS1, BTS2), whereby these base stations transmit the same signal to the MS in different time slots, and possibly in a different frequency.
Abstract: The soft handover of a channel or a base station according to the invention functions especially well in a TDMA system with a high TDMA milo. For the time of preparation of handover parallel physical links are formed between the mobile station (MS) and two or more base stations (BTS1, BTS2), whereby these base stations transmit the same signal to the mobile station (MS) in different time slots, and possibly in a different frequency.
117 citations
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AT&T1
TL;DR: In this paper, a handover of a mobile device from a macrocell to a femtocell is discussed, where the mobile device can also request macro-to-femto (MTF) handover.
Abstract: Access to a femtocell can be controlled as part of handover of a mobile device from macrocell to femtocell. Macro network platform issues a handover (HO) request towards femto network platform and a single virtual femto node, which represents a plurality of femto access points (APs). Location estimate(s) for the mobile device drives selection of a target femto AP. Selection of the target AP results in acceptance of the HO request. The mobile device also can request macro-to-femto (MTF) handover. HO neighbor list(s) is generated by decoding a network-issued identifier for each femto APs in a set of femtocells, and selectively ranking each femto AP based at least on channel quality; access privileges of the mobile device to each of the identified femto APs determines selectivity. Validation of mobile device's access right(s) drives acceptance of the MTF HO request to a top ranked femto AP.
117 citations
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30 Sep 2005
TL;DR: In this article, the handoff management system maximizes the communications capacity available from terrestrial air-to-ground cellular networks, while also integrating communications capabilities from satellite air to ground cellular networks and terrestrial cellular communications networks.
Abstract: The handoff management system maximizes the communications capacity available from terrestrial air-to-ground cellular networks, while also integrating communications capabilities from satellite air-to-ground cellular networks and terrestrial cellular communications networks. The communications capacity is maximized by dynamically allocating communications from the aircraft over multiple communications channels to multiple cells of the terrestrial air-to-ground cellular network, and to satellite air-to-ground cellular networks and terrestrial mobile networks. This approach effectively provides an increase in the call handling capacity available to any aircraft and permits a gradual transition of communications from one cell to the next cell, rather than requiring an abrupt handover of all traffic from the aircraft from one cell to the next cell.
117 citations