• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.306-311
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• 2006

When the WiBro/WLAN hierarchical network is structured, a dual mode access terminal should keep WLAN module with power on state for operating in WiBro network outside of WLAN hotspot zone. Power consumption of user's access terminal can be increased to maintain WLAN module power on state of dual mode access terminal in WiBro network outside of the hotspot zone. This paper focuses on power saving strategy for a dual mode access terminal in WiBro/WLAN Hierarchical network to overcome problems regarding power. We will apply information about hotspot in WiBro network to establish the efficient power saving strategy for dual mode access terminal.

• ETRI Journal
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• v.35 no.2
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• pp.253-258
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• 2013

We propose and demonstrate an efficient power-saving optical network unit (ONU) based on upstream traffic monitoring for 10-Gb/s wavelength division multiplexed passive optical networks (WDM-PONs). The power-saving mode controller uses a ${\mu}$-processor and traffic monitoring modules followed by the proposed power-saving processes to operate the sleep mode ONU. The power consumption of the ONU is effectively reduced from 19.3 W to 6.4 W when no traffic from the users is detected. In addition, we design a power-saving mechanism based on a cyclic sleep mode operation to allow a connectivity check between the optical line terminal and ONU. Our calculation results show that the WDM-PON ONU reduces the power consumption by around 60% using the proposed mechanism.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.311-316
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• 2005

The power saving mechanism of IEEE 802.16e operates in two modes; awake mode and sleep mode. While the user terminal transmits and receives packets in awake mode, it sleeps for a given interval to save the power consumption in sleep mode. The IEEE 802.16e specifies that the user terminal increases the sleep interval exponentially unless it has to wake up. In this paper, we analyze the performance of IEEE 802.16e power saving mechanism by considering down link traffic conditions. With the extensive simulations, we observe the trade-off between the power saving performance and the average packet delay. In addition, we observe that various performance parameters of IEEE 802.16e power saving mechanism are affected by the traffic patterns.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.790-797
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• 2006

IEEE 802.16e specifies two different power saving modes(PSM). One is sleep mode and the other is idle mode. These modes are different in that whether a mobile node maintains its state information with the serving base station or not. This difference results in different efficiency in consuming battery power of a mobile terminal. Therefore, it becomes important to analyze the performance of each power saving mode considering the parameters affecting the power consumption. In this paper, we propose a performance modeling framework of sleep mode and idle mode in terms of power saving efficiency. The analytical results are verified by computer simulations that idle mode is superior to sleep mode in power consumption of mobile node.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.1
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• pp.33-39
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• 2011

This paper considers a performance analysis of set-top box (STB) power saving schemes. STB converts the signal into content which is then displayed on the television (TV) screen, and there are typically two operation modes: on mode and stand-by mode. The total energy consumption (TEC), a typical measure of power consumption of STB, is defined by the sum of power consumption in each mode. Recently there are some works of STB power saving schemes that transit STB operation modes efficiently, and the mode transition time point of those schemes can be different. Thus it is required to develop a performance evaluation method that reflects mode transition time points of each scheme to get TEC correctly. This paper proposes a performance evaluation method for STB power consumption using Poisson process to consider the mode transition time point. By modeling STB mode transitions as events of Poisson process, the average time duration of STB mode is computed and accordingly the effect of power saving is evaluated. The performance evaluation result shows that the proposed method achieves 1 to 19% improvement in power consumption compared with a conventional performance evaluation method.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.4
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• pp.124-130
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• 2010

This paper considers a power saving technique of set-top box (STB) that turns the signal into content which is then displayed on the television (TV) screen. A traditional power saving scheme, Auto Power Down (APD), was devised to reduce the power consumption of STB. APD checks whether the user is watching TV over a period of time and enforces STB into stand-by mode when the check result reveals the user is not watching TV. This paper proposes an enhanced power saving scheme that transits STB operation mode to 'stand-by' immediately when STB recognizes the change of TV's external input signal. The proposed scheme does not require the monitoring time to check the users' watching TV, and transits to standby mode faster than the conventional APD, which results in better performance in power saving. The simulation result shows that the proposed scheme achieves 2 to 11% improvement in power consumption compared with the conventional APD.

• Journal of Korea Multimedia Society
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• v.11 no.10
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• pp.1392-1402
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• 2008

Home gateway is always full-powered for ubiquitous home services, and consumes much energy yearly. Power-saving algorithm to conserve this energy must reduce the energy consumption and preserve always-on services. Our algorithm predicts current idle period using the history of the past idle period when the idle period starts, and then determines whether the power mode is changed to the saving mode or not. On the power saving mode, it processes the simple protocol data for network control using proxying with no wakeup. And it changes the power mode to active mode when user's traffic exists. As the results of the simulation using real traffic, our algorithm saves the energy consumption from 14% to 49% as compared with existing method.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.4
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• pp.135-142
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• 2011

This paper proposes a performance evaluation method for power consumption of set-top box (STB) stand-by mode transition schemes. A stand-by mode transition scheme characterizes the timing of mode transition. The timing of mode transition affects the duration of stand-by mode operation, and the power consumptions of STB as well. Recently a fast stand-by mode transition scheme (FMT) has been proposed based on user input for selecting the device to be connected to TV. In this paper, we evaluate power consumption of FMT and a conventional mode transition scheme. For the computation of the duration of stand-by mode operation, the user input events are modeled as Poisson process. Simulation results based on the modeling reveals that the proposed scheme is more effective in power saving than the conventional scheme by up to 30%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.911-916
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• 2007

The home gateway, an equipment which works as an gateway for ubiquitous home network, relays all functions of a home network. The home gateway must always be connected in order to provide seamless services. However it gives unfavorable power consumption. Therefore the needs for working in maximum power saving mode while there is no data traffic and for invoking to the normal function when it is necessary. In this paper we survey the technical papers and the standards documents and provide an overview of power saving mode in the home gateway.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2826-2834
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• 2013

In mobile ad hoc networks (MANET), power-saving technology of mobile nodes is divided into transmit power control (TPC), power-saving mode (PSM), and routing. TPC and PSM are operated in physical layer but the routing is managed in network layer, so the design of a joint algorithm is needed to provide better performance. Therefore, in this paper, we propose a joint power-saving and routing algorithm for maximizing the network lifetime while satisfying the end-to-end data rate in ad hoc networks. The proposed algorithm first applies the TPC or PSM to reduce the power consumption of mobile nodes and then performs the routing by considering the decided node lifetime in order to maximize the path lifetime. Simulation results show that the proposed algorithm maximize the lifetime while satisfying the required rate according to the number of mobile nodes and the level of interference.