• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.1
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• pp.25-36
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• 2018

This paper presents a new airport slot allocation model that uses AIP model to balance the use of airport slots within existing capacity based on the limitation of capacity expansion of airport slots. This new model is called a 'balanced airport slot allocation model', which integrates the airport facility usage system, which is applied independently without linkage, with the airport slot allocation system, introducing the market logical characteristic of 'administered incentive pricing. In this paper, we propose a new proposal to dramatically change the airport slot allocation system in the current situation where the expansion of facilities is limited in the urgent problem of the airport slot shortage, and it is necessary to balance the airport slot allocation. Airline paying for the use of an airport slot can determine the slot of the desired time slot based on the costs incurred by differentiating in the new airport slot allocation model. This is a system that allows the airlines that are willing to pay a lot of money in the market to use preferred airport slots.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.73-78
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• 2004

There are random, continuous, and periodic allocation methods in the time slot sequence integrity for the multi-slot call. In the T-S-T switch, there are 2 time switch and the 2*2 space switch. Three time-slot allocation methods are suggested for the simulation. In the simulation, the searching times for time-slots on a multi-slot call is chosen to 32, and the simulation time is chosen to 100,000 seconds. Three kinds of calls are supposed for a multi-slot call : one time-slot call, two time-slot call, and 6 time-slot call. In the simulation, the carried traffic and the blocking probability are calculated on the 3 different traffic cases of 8:1:1, 6:2:2, 4:3:3(one time-slot : two time-slot : 6 time-slot) multi slot calls. It is shown that the blocking probability for the periodic time slot allocation method is best. As a result, the periodic time-slot allocation method is the proper one for the multi-slot ATM switch.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.115-122
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• 2021

In this paper, we propose a dynamic slot allocation scheme to improve the slot utilization rate in tactical multi-hop networks in which the channel condition varies due to node movements. The proposed scheme takes advantage of the fact that nodes that are more than three hops apart can use the same slot simultaneously. The frame is divided into two parts: the control period and the data period. To know the available slot information within two-hop distance, the node exchanges a slot allocation information with one-hop neighbors during the control period. The node can get the information on idle slots that are not used within two-hop distance but assigned already to other nodes that are more than three-hop away. The identified idle slot can be used by the node, which increases the slot utilization rate. The performance analysis results of the proposed scheme show that it increases the slot utilization rate sufficiently despite the overhead of the control period in the multi-hop networks of the future soldier system.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.189-198
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• 2001

In recent years, the predominant part in telecommunications is mobile communications. The next generation network is extending today's voice-only mobile networks to multi-service networks. ATM Network is possible to carry such multi-media traffic and it will be expect to use wireless ATM for the future mobile access network. One of manly important aspects for the performance of wireless ATM is the Medium Access Control (MAC) protocol. The MAC protocol must be able to satisfyingly handle the different ATM services (CBR, VBR, ABR and UBR) with their radically different performance requirements. Additionally, the MAC protocol must be able to cope with the complex radio environment where fading, multi-path propagation interference and burst-errors further complicate the situation. In this paper, a dynamic slot allocation algorithm in wireless ATM is proposed for an efficient channel sharing/media access at the MAC layer. We use equivalent capacity in the allocation of slots for VBR traffic which is variable along the time. It is simple and effective slot allocation method for VBR service. In particular, we consider the slot allocation of a session consisted of several connections for requirement of multimedia traffic. Simulation shows that the cell loss ratio is reduced by re-allocation of extra slots in Mobile Terminal (MT).

• Journal of Positioning, Navigation, and Timing
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• v.6 no.3
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• pp.117-123
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• 2017

In this paper, we propose a performance index that can compare the position estimation performance according to the time slot allocation order, which is superior in the position estimation performance in the operation of the Link-16 based relative navigation system. In order to verify the validity of the performance index, a software-based Link-16 relative navigation system performance analysis platform composed of a signal generator, a signal reception and navigation algorithm execution unit, and a performance analysis unit was designed. Using the designed software platform, we analyzed the relationship between proposed performance index and position estimation performance according to time slot allocation order in the same position reference (PR) arrangement. The performance index of the proposed time slot allocation is expected to be utilized not only for the Link-16 system, but also for the Time Division Multiple Access (TDMA)-based navigation system.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.4
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• pp.125-132
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• 2001

Traffic unbalance between uplink and downlink is one of the most notable characteristics in the next generation cellular mobile systems which provide multimedia services such as voice and video telephony, high-speed internet access, and mobile computing, etc. The CDMA/TDD system with unbalanced slot allocation between two links is a good solution for the traffic unbalance in this paper, we formulate the time slot and channel allocation problem for the CDMA/TDD systems in general multicell environments, which is to maximize the system capacity under the given traffic unbalance, and solve that problem by simulated annealing technique. Computational experiments show that the proposed scheme yields a good performance.

• Journal of the Korea Computer Industry Society
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• v.2 no.2
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• pp.165-180
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• 2001

This study is on the design and performance evaluation of a multi medium access control(MAC) protocol for multimedia access in the wireless ATM network. In general, MAC protocols for multimedia data transmission are classified into the fixed slot allocation algorithm that allocates base-station slots equally over terminals, and the dynamic slot allocation algorithm that with flexible penetration. The conventional slot allocation algorithms assign slots based on the average bandwidths required for various services types. Although the algorithms have a wide bandwidth for real-time-variant services, the slots are being wasted due the service types. To improve the slot waste problem, this thesis proposes a method that minimizes the waste by assigning variable slots based on the most appropriate bandwidth after a base-station analyzes the service type requested from terminals.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.101-107
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• 2017

Demand for air transportation in Korea keeps increasing, and the number of airport operations also grows as a result. The major two airports in Korea, Incheon International Airport and Gimpo International Airport, share the metropolitan airspace, which is crowd with air traffic. As air traffic increases in the metropolitan airspace, the demand for the airport operations would outnumber the capacities of these airports. However, there is a room to efficiently manage the shortage of the airport capacity due to the different distributions of operations in these airports. This study presents a dynamic slot allocation that allows exchanging slots according to the traffic demand. The dynamic allocation mitigates the airports' capacity problem but the airspace capacity itself should be increased in order to tackle the problem fundamentally.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12A
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• pp.1276-1285
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• 2007

Since the TD-SCDMA (Time Division-Synchronous Code Division Multiple Access) system is based on TDD (Time Division Duplexing), the uplink and downlink can be allocated asymmetrically according to the traffic e.g. Web browsing. Although this asymmetric allocation can increase the frequency utilization, it may cause time slot opposing, which implies the time slot is assigned in opposing direction between cells. The time slot opposing can generate significant interference between cells, which results in severe performance degradation. In the paper, a novel dynamic channel allocation (DCA) is proposed in the TD-SCDMA system, to mitigate the impact of time slot opposing considering smart antenna. When the smart antenna is applied in the system, the inter-cell interference is largely affected by beam pattern and beam direction between neighboring cells. Therefore, the time slot opposing and smart antenna should be considered together in the DCA. The intensive simulations show that the proposed scheme can improve the system capacity compared to the conventional DCA schemes.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.144-151
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• 2002

Future wireless communication systems are expected to provide a broad range of multimedia services in which the asymmetry of traffic load between uplink and downlink is a significant feature. The rode division multiple access system with tune division duplex mode (CDMA/TDD) is a good solution to cope with the traffic asymmetry problem. However. the TDD system is subject to inter-cell interference compared to frequency division duplex (FDD) system. Since both uplink and downlink share the same frequency in TDD. uplink and downlink may interfere each other especially when neighboring cells require different rates of asymmetry. Thus, time slot allocation for tells is an important issue in TDD. In this paper. we propose a genetic algorithm based time slot allocation scheme which maximizes the residual system capacity. The proposed scheme allows that each cell employ different level of uplink/downlink asymmetry and satisfies the interference requirement.