In this paper, We analysis of effective coverage extension for Tri-sector cellular systems using ... more In this paper, We analysis of effective coverage extension for Tri-sector cellular systems using Multi-hop Relay based on IEEE802.16j system. In the proposed international standard of IEEE 802.16j MMR (Mobile Multi-hop Relay) use of the omni-directional antenna, 3-sector and 6-sector antenna is considered to Base Station and Relay Station. Omni-directional antenna service can offer as all directions but a throughput decreases due to the signal interference of near Relay Stations. In the directional antenna, cause of an interference with the base station which it arranges an antenna so that a beam can have the direct and does with neighbor Base Station and Relay Station can be reduced interference, therefore the effective throughput is higher than the omni-directional antenna system. But, In case of Base Station and Relay Station use the directional antenna, the efficiency which the directional antenna has the Co-channel interference due to in the different cell by the channel reuse ...
In this paper, we evaluate the system throughput and the method of optimal wireless resource allo... more In this paper, we evaluate the system throughput and the method of optimal wireless resource allocation for the access zone (AZ) and relay zone (RZ) in downlink when the cell coverage is extended using the non-transparent Relay Station (RS) in a 2-hop cellular relay system based on IEEE802.16j, which uses the OFDMA-TDD structure. For the analyses, we first introduce the MAC (Media Access Control) frame structure in the non-transparent mode, then we investigate the interfering elements in both AZ and RZ for the network devices such as the Mobile Station (MS) and RS. Through computer simulation, we analyze the cell coverage extension and system throughput in terms of the distance between Base Station (BS) and RS, then we present the amount of the optimal allocation of wireless resource for the AZ and RZ in downlink using our results.
In low-power wide area networks (LPWAN), a considerable number of end devices (EDs) communicate w... more In low-power wide area networks (LPWAN), a considerable number of end devices (EDs) communicate with the gateway in a certain area, whereas for transmitted data, a low data rate and high latency are allowed. Long-range (LoRa), as one of the LPWAN technologies, considers pure ALOHA and chirp spread spectrum (CSS) in the media access control (MAC) and physical (PHY) layers such that it can improve the energy efficiency while mitigating inter-cell interference (ICI). This paper investigates the system throughput of LoRa networks under the assumption that the interferences between EDs for exclusive regions are ignored using CSS. In order to establish an analytical model for the performance of LoRa, we introduce the pure ALOHA capture model, which is the power threshold model. For this model, we assume that the interfering power is proportional to the length of the time overlapped. In addition, we discuss LoRa gain by comparing the total throughput of LoRa with that of non-CSS.
Abstract As the significance of increased power consumption in modern society is emphasized, the ... more Abstract As the significance of increased power consumption in modern society is emphasized, the need for technology to enhance energy efficiency is also increasing. The power consumption of buildings comprises a large proportion of the total energy consumption and systematic methods are needed in order to manage it effectively. This paper proposes a multiple power-based building energy management system (MPBEMS) for the efficient management of building energy. MPBEMS means a system that integrates and manages multiple power produced in one or more ways. The analysis of the big-data based power usage measured in different types of buildings utilizes the power distribution method between multiplepower sources. The paper also suggests and verifies an energy prediction model for efficient building energy management, called the Adaptive Energy Consumption Prediction (AECP) algorithm. This paper proposes a building energy management method using an energy prediction model and analyzes its efficiency by applying it to actual buildings. The result of the efficiency analysis using the proposed system shows an annual electricity rate reduction efficiency of 5%.
ABSTRACT In Fractional frequency reuse (FFR) technique, the available physical resource blocks ar... more ABSTRACT In Fractional frequency reuse (FFR) technique, the available physical resource blocks are reused among different cells in a manner that co-channel interference and/or inter-cell interference effect is reduced. However, when the resources are highly utilized, the sharing of these resources becomes exhausted and/or limited, and this leads to a high interference and hence high call blocking probability. Therefore, this paper proposes a call admission control in FFR to improve the performance of the FFR-based cellular system. The results of the two quality of service (QoS) constraints, the call blocking probabilities and the resource utilizations for users are used for some design criteria of the cell inner/outer area to maximize the throughput and hence for the evaluation of the system power efficiency.
This letter investigates the performance of cellular networks of a regular topology by proposing ... more This letter investigates the performance of cellular networks of a regular topology by proposing a profit maximization problem in which the center of each base station (BS) is d distance apart and each BS is Erlang-loaded. The profit of our interest is defined as the difference between the revenue earned from the average data rate of accepted users and the transmission and maintenance power costs. Compared with energy efficiency (EE) maximization in the literature, the proposed profit maximization problem enables us to price the average data rate for a BS to be profitable, to show a minimal traffic load from which a BS becomes profitable, and to show an optimal traffic load at which the maximum profit and EE can be achieved.
The Journal of Korea Information and Communications Society, 2013
이종 네트워크 환경에서 이종셀 간 간섭 제어를 위해 Almost Blank Subframes (ABS)이 제안 되었다. ABS에서는 서브프레임에 대한 자원 할당을 하지 않음으... more 이종 네트워크 환경에서 이종셀 간 간섭 제어를 위해 Almost Blank Subframes (ABS)이 제안 되었다. ABS에서는 서브프레임에 대한 자원 할당을 하지 않음으로써 동일 채널 간섭을 줄일 수 있다. 기존 연구에서는 ABS 기술의 성능 평가를 위한 수학적 모델링이 제안되지 않았다. 본 논문에서는 ABS 기술에 대한 수학적 모델을 제시하였다. 분석을 위한 가정에서 OFDMA 기반의 다중 반송파 (multi carrier) 시스템을 가정하였고, large-scale 페이딩을 가정하였다. 성능 평가로써 effective SINR에 대한 누적분포함수를 나타낸다. 시뮬레이션과 분석에 대한 결과 비교를 통해 수학적 모델에 대한 정확도를 보인다.
The Journal of Korea Information and Communications Society, 2013
Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve ... more Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve the throughput for LTE-Advanced systems. One important approach for CoMP is Joint Transmission (JT). However, the analytical model of JT has not been fully studied, as user equipments (UEs) receiving the desired signals from an adjacent base station (BS) as well as serving BS, or only serving BS were not distinguished. We derive a new analytical model to describe the call admission control in JT based systems. The performance measures of interest are the call blocking probability, and resource utilization. Furthermore, we compare the performance of JT-based systems and non-JT- based systems. The analytical results are in reasonable agreement with the simulation results.
In this paper, We analysis of effective coverage extension for Tri-sector cellular systems using ... more In this paper, We analysis of effective coverage extension for Tri-sector cellular systems using Multi-hop Relay based on IEEE802.16j system. In the proposed international standard of IEEE 802.16j MMR (Mobile Multi-hop Relay) use of the omni-directional antenna, 3-sector and 6-sector antenna is considered to Base Station and Relay Station. Omni-directional antenna service can offer as all directions but a throughput decreases due to the signal interference of near Relay Stations. In the directional antenna, cause of an interference with the base station which it arranges an antenna so that a beam can have the direct and does with neighbor Base Station and Relay Station can be reduced interference, therefore the effective throughput is higher than the omni-directional antenna system. But, In case of Base Station and Relay Station use the directional antenna, the efficiency which the directional antenna has the Co-channel interference due to in the different cell by the channel reuse ...
In this paper, we evaluate the system throughput and the method of optimal wireless resource allo... more In this paper, we evaluate the system throughput and the method of optimal wireless resource allocation for the access zone (AZ) and relay zone (RZ) in downlink when the cell coverage is extended using the non-transparent Relay Station (RS) in a 2-hop cellular relay system based on IEEE802.16j, which uses the OFDMA-TDD structure. For the analyses, we first introduce the MAC (Media Access Control) frame structure in the non-transparent mode, then we investigate the interfering elements in both AZ and RZ for the network devices such as the Mobile Station (MS) and RS. Through computer simulation, we analyze the cell coverage extension and system throughput in terms of the distance between Base Station (BS) and RS, then we present the amount of the optimal allocation of wireless resource for the AZ and RZ in downlink using our results.
In low-power wide area networks (LPWAN), a considerable number of end devices (EDs) communicate w... more In low-power wide area networks (LPWAN), a considerable number of end devices (EDs) communicate with the gateway in a certain area, whereas for transmitted data, a low data rate and high latency are allowed. Long-range (LoRa), as one of the LPWAN technologies, considers pure ALOHA and chirp spread spectrum (CSS) in the media access control (MAC) and physical (PHY) layers such that it can improve the energy efficiency while mitigating inter-cell interference (ICI). This paper investigates the system throughput of LoRa networks under the assumption that the interferences between EDs for exclusive regions are ignored using CSS. In order to establish an analytical model for the performance of LoRa, we introduce the pure ALOHA capture model, which is the power threshold model. For this model, we assume that the interfering power is proportional to the length of the time overlapped. In addition, we discuss LoRa gain by comparing the total throughput of LoRa with that of non-CSS.
Abstract As the significance of increased power consumption in modern society is emphasized, the ... more Abstract As the significance of increased power consumption in modern society is emphasized, the need for technology to enhance energy efficiency is also increasing. The power consumption of buildings comprises a large proportion of the total energy consumption and systematic methods are needed in order to manage it effectively. This paper proposes a multiple power-based building energy management system (MPBEMS) for the efficient management of building energy. MPBEMS means a system that integrates and manages multiple power produced in one or more ways. The analysis of the big-data based power usage measured in different types of buildings utilizes the power distribution method between multiplepower sources. The paper also suggests and verifies an energy prediction model for efficient building energy management, called the Adaptive Energy Consumption Prediction (AECP) algorithm. This paper proposes a building energy management method using an energy prediction model and analyzes its efficiency by applying it to actual buildings. The result of the efficiency analysis using the proposed system shows an annual electricity rate reduction efficiency of 5%.
ABSTRACT In Fractional frequency reuse (FFR) technique, the available physical resource blocks ar... more ABSTRACT In Fractional frequency reuse (FFR) technique, the available physical resource blocks are reused among different cells in a manner that co-channel interference and/or inter-cell interference effect is reduced. However, when the resources are highly utilized, the sharing of these resources becomes exhausted and/or limited, and this leads to a high interference and hence high call blocking probability. Therefore, this paper proposes a call admission control in FFR to improve the performance of the FFR-based cellular system. The results of the two quality of service (QoS) constraints, the call blocking probabilities and the resource utilizations for users are used for some design criteria of the cell inner/outer area to maximize the throughput and hence for the evaluation of the system power efficiency.
This letter investigates the performance of cellular networks of a regular topology by proposing ... more This letter investigates the performance of cellular networks of a regular topology by proposing a profit maximization problem in which the center of each base station (BS) is d distance apart and each BS is Erlang-loaded. The profit of our interest is defined as the difference between the revenue earned from the average data rate of accepted users and the transmission and maintenance power costs. Compared with energy efficiency (EE) maximization in the literature, the proposed profit maximization problem enables us to price the average data rate for a BS to be profitable, to show a minimal traffic load from which a BS becomes profitable, and to show an optimal traffic load at which the maximum profit and EE can be achieved.
The Journal of Korea Information and Communications Society, 2013
이종 네트워크 환경에서 이종셀 간 간섭 제어를 위해 Almost Blank Subframes (ABS)이 제안 되었다. ABS에서는 서브프레임에 대한 자원 할당을 하지 않음으... more 이종 네트워크 환경에서 이종셀 간 간섭 제어를 위해 Almost Blank Subframes (ABS)이 제안 되었다. ABS에서는 서브프레임에 대한 자원 할당을 하지 않음으로써 동일 채널 간섭을 줄일 수 있다. 기존 연구에서는 ABS 기술의 성능 평가를 위한 수학적 모델링이 제안되지 않았다. 본 논문에서는 ABS 기술에 대한 수학적 모델을 제시하였다. 분석을 위한 가정에서 OFDMA 기반의 다중 반송파 (multi carrier) 시스템을 가정하였고, large-scale 페이딩을 가정하였다. 성능 평가로써 effective SINR에 대한 누적분포함수를 나타낸다. 시뮬레이션과 분석에 대한 결과 비교를 통해 수학적 모델에 대한 정확도를 보인다.
The Journal of Korea Information and Communications Society, 2013
Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve ... more Coordinated multi-point transmission (CoMP) is considered to be a promising technique to improve the throughput for LTE-Advanced systems. One important approach for CoMP is Joint Transmission (JT). However, the analytical model of JT has not been fully studied, as user equipments (UEs) receiving the desired signals from an adjacent base station (BS) as well as serving BS, or only serving BS were not distinguished. We derive a new analytical model to describe the call admission control in JT based systems. The performance measures of interest are the call blocking probability, and resource utilization. Furthermore, we compare the performance of JT-based systems and non-JT- based systems. The analytical results are in reasonable agreement with the simulation results.
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Papers by Seung-Yeon Kim