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Author

Daehyoung Hong

Other affiliations: Motorola
Bio: Daehyoung Hong is an academic researcher from Sogang University. The author has contributed to research in topics: Handover & Scheduling (computing). The author has an hindex of 15, co-authored 61 publications receiving 3156 citations. Previous affiliations of Daehyoung Hong include Motorola.


Papers
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Journal ArticleDOI
TL;DR: A traffic model and analysis for cellular mobile radio telephone systems with handoff, which shows, for example, blocking probability, forced termination probability, and fraction of new calls not completed, as functions of pertinent system parameters.
Abstract: A traffic model and analysis for cellular mobile radio telephone systems with handoff are described. Three schemes for call traffic handling are considered. One is nonprioritized and two are priority oriented. Fixed channel assignment is considered. In the nonprioritized scheme the base stations make no distinction between new call attempts and handoff attempts. Attempts which find all channels occupied are cleared. In the first priority scheme considered, a fixed number of channels in each cell are reserved exclusively for handoff calls. The second priority scheme employs a similar channel assignment strategy, but, additionally, the queueing of handoff attempts is allowed. Appropriate analytical models and criteria are developed and used to derive performance characteristics. These show, for example, blocking probability, forced termination probability, and fraction of new calls not completed, as functions of pertinent system parameters. General formulas are given and specific numerical results for nominal system parameters are presented.

1,654 citations

Proceedings Article
01 Jan 1986
TL;DR: A traffic model and analysis for cellular mobile radio telephone systems with handoff, which shows, for example, blocking probability, forced termination probability, and fraction of new calls not completed, as functions of pertinent system parameters.
Abstract: A traffic model and analysis for cellular mobile radio telephone systems with handoff are described. Three schemes for call traffic handling are considered. One is nonprioritized and two are priority oriented. Fixed channel assignment is considered. In the nonprioritized scheme the base stations make no distinction between new call attempts and handoff attempts. Attempts which find all channels occupied are cleared. In the first priority scheme considered, a fixed number of channels in each cell are reserved exclusively for handoff calls. The second priority scheme employs a similar channel assignment strategy, but, additionally, the queueing of handoff attempts is allowed. Appropriate analytical models and criteria are developed and used to derive performance characteristics. These show, for example, blocking probability, forced termination probability, and fraction of new calls not completed, as functions of pertinent system parameters. General formulas are given and specific numerical results for nominal system parameters are presented.

920 citations

Journal ArticleDOI
01 Oct 1989
TL;DR: A priority oriented channel access scheme for cellular mobile radio telephone systems serving vehicular and portable radio telephone users is described in this article, where the calls generated are divided into three different classes: new vehicular calls, new portable calls and hand-off calls.
Abstract: A priority oriented channel access scheme for cellular mobile radio telephone systems serving vehicular and portable radio telephone users is described. The calls generated are divided into three different classes: new vehicular calls, new portable calls and hand-off calls. Priority is given to hand-off calls over new calls and to vehicular calls over portable calls. Appropriate analytical models and criteria are developed and used to derive performance characteristics. Blocking and forced termination probabilities for each kind of user are determined as functions of system parameters. Noncompleted call probability is defined as a useful performance measure for each kind of user. The effects of priorities and hand-off procedures on performance characteristics are investigated. General formulas are given and specific numerical results for nominal system parameters are presented.

102 citations

Proceedings ArticleDOI
01 Oct 2010
TL;DR: Simulation results show that the HO performance of the “adaptive method” is greatly improved compared to that of applying fixed TTT values, and the performance ofthe “grouping method’s” performance, using proposed criteria and proper T TT values, is comparable to those of the“ Adaptive method.”
Abstract: In this paper, we evaluate handover (HO) performance when we apply various time-to-trigger (TTT) methods in self-organizing network (SON)-based long term evolution (LTE) systems. Although TTT can mitigate the wasteful ping-pong HO effect, it also can cause undesirable radio link failure (RLF) due to delayed HO. The optimal HO timings that produce the lowest ping-pong rate within allowable RLF rate vary depending on user equipment (UE) speeds and neighboring cell configurations. To achieve efficient HO timings, we propose and investigate two methods: “adaptive” and “grouping.” In the “adaptive method,” we select the adaptive TTT value for each UE speed based on RLF rate of 2%. The “grouping method” classifies UE speeds into three ranges and assigns the proper TTT value to each range. To apply the LTE specification more effectively, we suggest the criteria of grouping, and propose the proper TTT value for each range. We consider HO in two neighboring cell configurations: from a macro cell to either a macro cell or a pico cell. Simulation results show that the HO performance of the “adaptive method” is greatly improved compared to that of applying fixed TTT values. The results also show that the performance of the “grouping method”, using proposed criteria and proper TTT values, is comparable to that of the “adaptive method.”

81 citations

Journal ArticleDOI
TL;DR: This work proposes a couple of particle filtering frameworks for beam tracking and shows outperforming result of an auxiliary particle filtering approach over recently proposed tracking approaches.
Abstract: We propose approaches to the problem of multi-paths beam tracking in millimeter-wave (mmWave) mobile communications. Precise angle tracking is necessary to take advantage of beamforming technology in this mmWave band. The mobile channel is a highly nonlinear function with respect to the state that comprises the beam angle and the channel path gain. Therefore, the beam angle tracking is challenging and crucial. We propose a couple of particle filtering frameworks for beam tracking and show outperforming result of an auxiliary particle filtering approach over recently proposed tracking approaches.

46 citations


Cited by
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Proceedings Article
01 Jan 1991
TL;DR: It is concluded that properly augmented and power-controlled multiple-cell CDMA (code division multiple access) promises a quantum increase in current cellular capacity.
Abstract: It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

2,951 citations

01 Jan 2007
TL;DR: In this paper, the authors provide updates to IEEE 802.16's MIB for the MAC, PHY and asso-ciated management procedures in order to accommodate recent extensions to the standard.
Abstract: This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

1,481 citations

Journal ArticleDOI
TL;DR: This article provides a detailed discussion on reuse partitioning schemes, the effect of handoffs, and prioritization schemes, and other important issues in resource allocation such as overlay cells, frequency planning, and power control.
Abstract: This article provides a detailed discussion of wireless resource and channel allocation schemes. The authors provide a survey of a large number of published papers in the area of fixed, dynamic, and hybrid allocation schemes and compare their trade-offs in terms of complexity and performance. We also investigate these channel allocation schemes based on other factors such as distributed/centralized control and adaptability to traffic conditions. Moreover, we provide a detailed discussion on reuse partitioning schemes, the effect of handoffs, and prioritization schemes. Finally, we discuss other important issues in resource allocation such as overlay cells, frequency planning, and power control.

1,273 citations

Patent
25 Apr 2002
TL;DR: In this article, a system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality OF frequencies using repetitive time frames, each said time frame comprising a sequence of time slots.
Abstract: A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory. The system includes a multiplexer for multiplexing the information signals onto the assigned channel; and a transmitter for transmitting the information signals to the destination subscriber unit using the assigned channel.

877 citations

Journal ArticleDOI
TL;DR: A novel framework for dynamically organizing mobile nodes in wireless ad hoc networks into clusters in which the probability of path availability can be bounded is presented, which supports an adaptive hybrid routing architecture that can be more responsive and effective when mobility rates are low and more efficient when Mobility rates are high.
Abstract: This paper presents a novel framework for dynamically organizing mobile nodes in wireless ad hoc networks into clusters in which the probability of path availability can be bounded. The purpose of the (/spl alpha/, t) cluster is to help minimize the far-reaching effects of topological changes while balancing the need to support more optimal routing. A mobility model for ad hoc networks is developed and is used to derive expressions for the probability of path availability as a function of time. It is shown how this model provides the basis for dynamically grouping nodes into clusters using an efficient distributed clustering algorithm. Since the criteria for cluster organization depends directly upon path availability, the structure of the cluster topology is adaptive with respect to node mobility. Consequently, this framework supports an adaptive hybrid routing architecture that can be more responsive and effective when mobility rates are low and more efficient when mobility rates are high.

747 citations