• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.3
• /
• pp.906-918
• /
• 2012

Wireless Fidelity (WiFi) and Wireless microphone are assumed to operate on adjacent channels in TV White Spaces(TVWS). The Scenario of WiFi potentially interfering with Wireless microphone is analyzed through Minimum Coupling Loss (MCL) and Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) based on the Monte-Carlo simulation method. In the case of single WiFi interfering with Wireless microphone, the protection distance between WiFi and the Wireless microphone should be at least 25.12 m to avoid WiFi impact on Wireless microphone. When the active number of WiFi is 12, the guard band between WiFi and Wireless microphone should not be less than 4.97 MHz to guarantee that WiFi does not interfere with the Wireless microphone.

• Journal of Digital Convergence
• /
• v.11 no.4
• /
• pp.243-249
• /
• 2013

In this paper, GPS(Global Positioning System) that can be used outdoors and GPS(Global Positioning System) is not available for indoor Wi-Fi(Wireless Fidelity) using the Android-based location information system has been designed and implemented. Pedestrians in a room in order to estimate the location of the pedestrian's position, regardless of need to obtain the absolute position and relative position, depending on the movement of pedestrians in a row it is necessary to estimate. In order to estimate the initial position of the pedestrian Wi-Fi Fingerprinting was used. Most existing Wi-Fi Fingerprinting position error small WKNN(Weighted K Nearest Neighbor) algorithm shortcoming EWKNN (Enhanced Weighted K Nearest Neighbor) using the algorithm raised the accuracy of the position. And in order to estimate the relative position of the pedestrian, the smart phone is mounted on the IMUInertial Measurement Unit) because the use did not require additional equipment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.507-510
• /
• 2011

As the amount of the wireless mobile products like a 'Smart phone' used increases, the studies about the Location Based Service (LBS) is highly increasing. Outdoor location determination can use the GPS which is built-in in the wireless mobile products. However, it is not possible to use GPS inside the huge cruise bigger than a normal building, it is regarded to consider Indoor location determination which is appropriate at the inside environment. Wi-Fi (Wireless Fidelity) does not need an extra installation process because it is already installed here and there inside the building. In this respect, Wi-Fi has low price competitiveness compared to other wireless sensor products. In this paper, I will introduce 'Bayesian Algorithm' which can recognize useful space with Wi-Fi signal.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11B
• /
• pp.1357-1362
• /
• 2011

TV White Spaces (TVWS) are freed up after transition from analog television to Digital Television (DTV). Some wireless communications are allowable to operate in TVWSs, such unlicensed Wireless Fidelity (WiFi). Because TVWSs are located in the VHF and UHF bands, TVWSs can provide significantly better coverage and wall penetration inside buildings and other structures than the 2.4 GHz and 5 GHz WiFi frequencies currently in use. Therefore, this paper assumes that WiFi will be deployed in TVWSs. However, the interference impact of WiFi on DTV has to be taken into account. The interference probability in DTV receiver was evaluated by using Spectrum Engineering Advanced Monte-Carlo Analysis Tool (SEAMCAT). As a result, when 20 WiFi UEs are simultaneously operating at the maximum transmit power of 23 dBm and the guard band is 22 MHz, the protection distance should be at least 6 km to meet the interference probability of 5% in DTV receiver.

• Journal of Advanced Navigation Technology
• /
• v.19 no.6
• /
• pp.601-606
• /
• 2015

Recently wireless data services have widely spread on various multimedia devices such as smart phones and tablets. Existing wired data services have been replaced by wireless data services using mobile devices. Especially domestic mobile devices supporting both Wireless-Fidelity (Wi-Fi) and long term evolution (LTE) services have increased steadily. While Wi-Fi network is provided free of charge, LTE network is offered to pay for. Therefore, mobile devices provide smart network switch to support both preferred Wi-Fi and LTE networks. However, such handover and roaming between Wi-Fi and LTE networks can cause data connection stop in spite of charged data services. This paper has proposed the method to overcome data connection stop for guaranteeing seamless data service during handover and roaming procedures between networks.

• Journal of IKEEE
• /
• v.25 no.2
• /
• pp.252-260
• /
• 2021

In this paper, a method of using Software Defined Radio (SDR) is proposed for improving the accuracy of identifying two kinds of signals as Wireless Fidelity (Wi-Fi) signal and Bluetooth signal at the same frequency band of 2.4 GHz based on the time-domain signal characteristic. An SDR device was set up for collecting transmitting signals from Wi-Fi access points (Wi-Fi) and mobile phones (Bluetooth). Different characteristics between Wi-Fi and Bluetooth signals were extracted from the measured result. The SDR device is programmed with a Wi-Fi and Bluetooth detection algorithm and a collision detection algorithm to detect and verify the Wi-Fi and Bluetooth signals based on collected IQ data. These methods are necessary for some applications like wireless communication optimization, Wi-Fi fingerprint localization, which helps to avoid interference and collision between two kinds of signals.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.2
• /
• pp.272-278
• /
• 2015

This paper analyzed interference impact between wireless headset and Wireless Fidelity which get a high possibility of simultaneously operating in the Industry Science Medical(ISM) bands. Analysis methods of Minimum Coupling Loss(MCL) and Monte Carlo(MC) were applied by using the characters and parameters referenced to Institute of Electrical and Electronic Engineers(IEEE) 802.11b. The protection distance between interferer (WiFi transmitter) and victim (Wireless headset receiver) was calculated through the MCL. The protection distance was obtained for the case of single interferer, and the maximum allowable number of multiple interferers was computed according to the cell radius of a victim system to meet 5 % below of interference probability by using a statistical analysis based on the MC method. The analysis results are expected to be used as a guideline to coexist the wireless headset and low power devices in the ISM band.

• Journal of Satellite, Information and Communications
• /
• v.9 no.2
• /
• pp.101-106
• /
• 2014

As ESL(Electronic Shelf Label) system is increased at the market in the world, the interference between ESL system and Wi-Fi(Wireless Fidelity) Cellular Phone at 2.4GHz becomes issue. The interference scenario and propagation of the Extended HATA Model were established to analyze the interference from Wi-Fi Cellular Phone into ESL system. Through simulation results based on SEAMCAT(Spectrum Engineering Advanced Monte Carlo Analysis Tool), separation distance was obtained to protect ESL system from Wi-Fi Cellular Phone interference.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2014.06a
• /
• pp.234-236
• /
• 2014

본 논문은 기존의 T-DMB(Terrestrial Digital Multimedia Broadcasting) 재난 정보 신호를 Wi-Fi(Wireless Fidelity)를 이용하여 재전송하는 기법을 제시한다. 각종 재난이 발생하는 지역의 T-DMB 난시청 구간에 대해서 Wi-Fi 를 이용하여 재난 정보 신호를 재전송함으로써 재난 정보 신호를 받지 못하는 시청자에게 신속한 재난 정보 서비스를 가능하게 해준다. 재난이 발생한 지역에서 T-DMB 재난 정보를 수신할 수 없는 시청자에게 AP(Access Point)를 이용하여 재난 정보를 재전송하는 것이 목적이다. 이에 본 논문에서 제안하는 Wi-Fi 를 이용한 재전송 기법은 T-DMB 신호를 수신하지 못한 시청자에게 재난정보를 효율적으로 재전송함으로써 해당 지역에 더 높은 재난 정보 수신률을 제공할 뿐만 아니라 국민의 생명과 안전을 도모할 수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.8
• /
• pp.1074-1081
• /
• 2021

It has recently been noticed that the headway of unlicensed wireless technology is necessary as user's demands of wireless tech increase and the development of high-speed data service by using low-power short-range wireless network is needed. Hence, it is inevitable to study sharing and coexistence for broadband spectrum of diverse unlicensed application with wide bandwidth. In this paper, an interference examination between unlicensed WiFi (Wireless Fidelity) in the 6GHz and OB (Outside Broadcasting) system which is an incumbent service in the same frequency band was conducted and it suggests separation distance for the coexistence. Thus, MCL (Minimum Coupling Loss) and MC (Monte Carlo) methods were used to set up interference scenarios for the interference analysis and compute the separation distance between two systems according to the same frequency band and frequency separation.