• Journal of Korean Institute of Industrial Engineers
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• v.34 no.2
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• pp.151-159
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• 2008

An efficient location registration scheme is essential to accommodate continuously increasing mobile subscribers and to offer a variety of multimedia services with good quality. In this study, we consider a distance-based registration scheme where the number of location areas varies on the basis of cell-by-cell, not of ring-by-ring, to analyze the optimal size of the location area. Using our proposed cell-by-cell distance-based registration scheme with random walk mobility model, we analyze a variety of circumstances to obtain the optimal number of cells for location area that minimizes total signaling traffic on radio channels. From our analysis results, we show that the optimal number of cells for location area is between 4 and 6 in most cases, and our cell-by-cell distance-based location registration scheme has less signaling traffic than optimal ring-by-ring distance-based location registration scheme where optimal distance threshold is 2 (thus the optimal number of cells for location area is 7).

• Korean Management Science Review
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• v.25 no.2
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• pp.73-80
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• 2008

The location area planning is to assign cells to the location areas of a wireless communication network in an optimum manner. The two important cost components are cost of location update and cost of paging that are of conflicting in nature; i.e., minimizing the registration cost might increase the search cost. Hence, it is important to find a compromise between the location update and paging operations such that the cost of mobile terminal location tracking cost is a minimum. The complete mobile network is divided into location areas. Each location area consists of a group of cells. In fact this is shown to be an NP-complete problem in an earlier study. In this paper, we use an ant colony optimization method to obtain the best/optimal group of cells for a given a network.

• IE interfaces
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• v.16 no.4
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• pp.507-514
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• 2003

In personal communication systems location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. The rest of cells in the location area are included into the second paging area. To reduce the paging cost the first paging area is decided by reflecting various residence patterns of mobile terminals. For an incoming call, the sequential paging is performed in the order of the paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than an existing strategy that uses the anchor cell in the location area.

• Korean Management Science Review
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• v.29 no.1
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• pp.143-152
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• 2012

Location area planning (LAP) problem is to partition the cellular/mobile network into location areas with the objective of minimizing the total cost in location management. The minimum cost has two components namely location update cost and searching cost. Location update cost is incurred when the user changes itself from one location area to another in the network. The searching cost incurred when a call arrives, the search is done only in the location area to find the user. Hence, it is important to find a compromise between the location update and paging operations such that the cost of mobile terminal location tracking cost is a minimum. The complete mobile network is divided into location areas. Each location area consists of a group of cells. This partitioning problem is a difficult combinatorial optimization problem. In this paper, we use particle swarm optimization (PSO) to obtain the best/optimal group of cells for 16, 36, 49, and 64 cells network. Experimental studies illustrate that PSO is more efficient and surpasses those of precious studies for these benchmarking problems.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1179-1186
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• 1996

A previous location area scheme was proposed for cellular network, in which the size of location area of a user is dynamically determined by is current mobility and call arrival rate as the burden of system reaches the minimum. This scheme, however, doesn't consider other individual's movement pattern respectively because of allocating location area with a system's fixed pattern. When mobile subscribers move fast, this scheme allocates especially so large location area to reduce the number of location registration that it makes much paging cost. In this paper, we suggest new dynamic location area management which allocates location area according to each subscriber's mobility regarding its current location as center point. This new scheme allocates fast subscriber larger location area, which resulted in reducing the number of location registration. And small area paging reduces paging cost.

• Journal of the Korean Society of Safety
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• v.37 no.1
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• pp.1-11
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• 2022

This numerical study investigates the effects of the size of the natural smoke vent area (10% and 1% of the floor area) and the location of the fire source (i.e., at the side and center of the stage) on the temperature distribution in the compartment and velocity distribution and mass flow rate of flow through a natural smoke vent for a reduced-scale model of a theater stage. Then, the mass flow rate of outflow through the natural smoke vent in the event of a fire for a real-scale theater stage was examined. The case with the larger natural smoke vent area and central fire source location showed lower temperature distributions and higher mass flow rates of outflow and inflow than the case with the smaller natural smoke vent area and side fire source location. The trends of the temperature distributions were closely related to those of the mass flow rates for the outflow and inflow. Additionally, the case with the larger natural smoke vent area and central fire source location exhibited the most non-uniform flow velocity distribution in all cases tested. A bidirectional flow, in which the outflow and inflow occur simultaneously, was observed through the natural smoke vent. In the event of a fire situation in a real-scale theater stage, it was predicted that the case with the larger natural smoke vent area and central fire source location would have a mass flow rate of outflow that is 43.53 times higher than that of the case with the smaller natural smoke vent area and side fire source location. The present results indicate that the natural smoke vent location should be determined by considering the location in a theater stage where a fire can occur.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.661-663
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• 2002

This paper introduces a dynamic location management with hierarchical location area, which helps in reducing location update(LU) and paging cost and hence total location management cost. Users are assigned to appropriate location area level utilizing the call-to-mobility ratio(CMR) value. CMR values are calculated each time a user enters a new cell by computing its mobility rate and incoming call rate, which are the two key factors for defining the size of the location area.

• Journal of the Korean housing association
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• v.9 no.3
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• pp.33-46
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• 1998

This study attempts to find out the characteristic of apartment housing sales information and housing choice behavior according to housing location. For this purpose, the apartment housing sales information in newspaper advertising was investigated and analyzed by advertising appeals to clarify the phenomenon of apartment housing sales and the components of home environmental quality according to housing location in Pusan. Then the field survey has been carried out based on 176 households living in Pusan. The major findings are as follows: 1) The components of home environment through AAs were divided into three categories of appeals: residential area, site area and dwelling unit area. 2) Apartment housing developments were differentiated according to period of development and occupancy scales according to housing location. 3) The results of field survey showed users' housing location. 4) The characteristics of apartment housing sales information according to housing location were revealed those characteristic were concentrated on the category of residential area than site area or dwelling unit area. But in housing choice behavior, the characteristics of housing location appeared in all categories of home environment. Therefore, for better apartment housing development and planning, the characteristics of housing location need to be considered more actively.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.25-28
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• 1999

Consider connection-oriented wireless cellular net-works. To establish a circuit or virtual circuit in such a network, a paging message is broadcast over a region at which the destined mobile station is presumed to reside, (identified as a paging area). For an effective paging mechanism, it is desirable to provide the location information of mobile stations to the network. In this paper, we consider a mobile controlled location update scheme under which each mobile station periodically reports its current location information to the network by using an inherent timer (without measuring the power of signals transmitted from base stations). Based on the latest information about a mobile station's location, a paging area is selected to page the mobile station. Note that under this scheme, a mobile station may not yet have reported its location change while sojourning out of the current paging area. In such situation, the mobile station can not receive a paging message destined to it. Frequent location updates can reduce the paging failure rate incurred by mobile stations'sojourning out of the paging area. However, larger bandwidth is needed for location update as the location update rate is increased. On the other hand, as the size of the paging area is increased, the paging failure rate is decreased, while larger bandwidth is required for paging. Thus, we first present a model for mobility, paging and location update processes, and secondly investigate the effect of network parameters on the paging failure rate and the amount of bandwidth used for paging and location update. Finally, we formulate problems to find proper values for the location update rate and paging area size under the constraints on the bandwidth usage levels for location update and paging.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.425-432
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• 2003

In personal communication systems, location management of mobile terminals is required to connect incoming calls to the mobile terminals. Investigation of effective location update and paging strategies is important to reduce the cost of location management. In this study, we propose a paging strategy considering the mobile terminals' residence patterns. The first paging area is introduced, which is characterized by the set of cells in the location area where mobile terminals usually stay for a significant period of time. We propose the decision criterion of the first paging area by comparing the cost against zone-based strategy. For an incoming call. we perform the sequential paging by the order of the first paging area and the rest of cells in the location area called by the second paging area. Thus the paging cost is greatly reduced, especially when the called mobile terminal is located in the first paging area. The proposed strategy is expected to be more effective than existing strategy using anchor cell in the location area because it reflects various residence patterns of mobile terminals.