Earticle

본 논문에서는 무선 다중 접속 기술을 이용하여 1080i 해상도와 최대 30fps 프레임레이트를 갖는 휴대용 동영상 전송 장치를 설계 및 제작하였다. 이 장치의 영상획득 지연시간은 16us이며 지터는 평균 21ms이다. 이 장치는 다양한 통신망 에 선택적으로 접속이 가능하도록 설계하였으며 전송 시험을 위하여 서버와 관제를 위한 뷰어를 구현하였다. LTE망을 이용한 전송실험의 경우, 3Mbps 전송 시 211ms 지연시간을 타나냈으며 인말새트 위성망을 이용한 실험에서는 265kbps 전송 시 1fps 프레임레이트로 렌더링되는 것을 확인하였다.

In this paper, we designed and implemented a mobile video transmission device with 1080i resolution and 30fps frame rate using wireless multi-access technologies. The video acquisition delay time of 16us and jitter of 21ms for this equipment were obtained, respectively. The device is designed to access various communication networks. In order to evaluate the performance of its video transmission capability, a server and monitoring viewer are implemented. In the performance test using LTE network, 211ms delay time was obtained at 3Mbps transmission. Rendering of 1fps frame rate at the 265kbps transmission was confirmed for the transmission test using Inmarsat network.

본 논문은 다중 세션 지원 방법에 관한 것으로, 이동 단말기가 멀티미디어 서비스를 위한 SDP (Sesion Data Protocol) 설정 시 각 프로토콜 계층을 구분하기 위한 식별자를 세션에 따라 다르도록 설정하고, 계층별 식별자를 연계하여 복수의 세션을 구분한다. 다중 세션을 처리하기 위하여 주 처리 태스크와 부 태스크를 둔다. 이 태스크는 QoS 속성을 사용하여 무선 인터페이스 상에서 세션 단위로 트래픽 관리를 수행한다. 이를 기반으로 큐잉, 수락 제어, 부하 제어, 자원 할당 그리고 스케쥴링이 세션의 우선순위를 기반으로 처리된다. 이를 통하여 하나의 MT에 동시에 여러 종류의 서비스를 제공할 수 있게 함으로써 음성, 영상, 데이터 서비스 등 자원 할당 요구사항이 서로 다른 서비스들이 공존 가능하게 된다.

Our paper deals with a method for supporting multiple call/sessions in a mobile terminal. The different identifier for each protocol layer is assigned to each sesion when a mobile terminal sets SDP for multimedia services. In particular, QoS based tasks are used for managing the traffics in radio interface. Also, queuing, admision control, load control, resource allocation and scheduling are done based on the priority of sesions. The various multimedia services which is different in the requirement of resource allocation are able to be serviced simultaneously because a mobile terminal can provide the various services based on this scheme.

본 논문에서는 이동형 위성단말에서 발생하는 shadowing 채널에 ARQ 기술을 적용하여 성능을 확인한다. shadowing은 위성단말이 이동하면서 생기는 신호 단절이다. 신호 단절을 보상하기 위해 신호를 재전송하는 ARQ기술을 사 용할 수 있다. 위성통신에서는 송신 데이터와 ack채널에서 shadowing이 발생한다. 두 채널에서 발생하는 shadowing의 상관 관계에 따라 ARQ 기술 적용 후 예상되는 전송량은 다르다. 따라서 shadowing채널에 ARQ 기술을 적용할 경우 예상되는 성능을 확인한다. 분석결과 단말이 송신할 경우와 수신할 경우 전송량의 차이를 보였고, 수식적으로 성능을 예측할 수 있음을 보였다.

In this paper, the performance is confirmed by applying ARQ technology to the shadowing channel occurring in the mobile satellite terminal. Shadowing is a signal disruption caused by movement of a satellite terminal. An ARQ technique may be used to retransmit the signal to compensate for signal interruption.In satellite communication, shadowing occurs in the transmission channel and the ack channel. The expected throughput after applying ARQ technique is different according to the correlation of shadowing occurring in two channels. Therefore, we confirm the expected performance when ARQ is applied in the shadowing channel. As a result, it is shown that the amount of transmission is different when the terminal transmits and receives, and the performance can be predicted formally.

Based on the powerful open interface of WeChat enterprise account features, a site investigation system is proposed for management of hydraulic engineering projects. The implemented functions include integrated photographing, GPS based positioning and information submission from handheld mobile devices. By leveraging cloud computing and mobile internet technologies, all the site investigation information is collected by designers on the unified mobile terminal including smart phones, tablets, and laptops. The proposed system provides various services, such as batch uploading, geological position mapping, data query and data downloading of the investigated information of specific hydraulic engineering project. Moreover, high level functions are realized through high-precision location based service, synchronous saving, resource sharing and quick search. Our system outperforms and changes the traditional working mode of site investigation of hydraulic engineering projects, as well as improves the working efficiency and accuracy for data collection in the whole life of the project management.

Face recognition systems gain flexibility and cost efficiency while being integrated into a wireless network. In this paper, we describe a study on the implementation of facial recognition application system using wireless devices. The facial recognition system transmits the pictures photographed by wireless terminals or smart phones and recognizes/authenticates the faces. This system can be applied to several areas such as indolence management, access management and attendance management. The previous facial recognition systems are mostly based on the wire system but our system uses mobile terminals or smart phones.

Remotely controlled Home Automation is popular these days, but it is usually applicable to recent appliances only. In order to utilize old devices in the automation we have developed a model that integrates conventional electric/electronic devices into the automation. We have named the modelWhaut (Wireless Home AUTomation), in which a mobile terminal is used to trigger the control through Weband an embedded unit is used to control the target appliances. We have demonstrated usefulness of theWhaut model by implementing a mobile terminal basedsystem for controlling a conventional air-conditioner.

This manuscript introduces a novel design concept for advanced mobile terminals with radio network aggregation capability and enhanced Quality of Service (QoS) provisioning for various multimedia services in heterogeneous wireless and mobile networks. We establish a new module that provides the best QoS and lowest cost for any given multimedia service (voice, video and audio) by using simultaneously all available wireless and mobile networks for a given traffic flow. The performance of our proposal is evaluated using simulations with multimode mobile stations carrying multimedia traffic in heterogeneous environment with coexistence of multiple Radio Access Technologies, such as 3G, 4G as well as future 5G radio access networks. The analysis of the proposed framework for radio networks aggregation in advanced mobile terminals has shown overall better performances regarding the achievable throughput and multimedia access probability in heterogeneous wireless and mobile environment.

In passive bearing-only localization of onboard mono-station, if abnormal error existed in observed value, using extended Kalman filter (EKF) algorithm can lead to biased results. For enhance the robustness of the algorithm, to construct robustness equivalent gain matrix on the basis of standardized predicted residual, and apply the robustness EKF algorithm to passive bearing-only localization of onboard mono-station. According to the characteristics of inefficient robustness EKF algorithm, combined with F distribution statistics, propose the mono-station passive location algorithm based on the improved extended Kalman filtering, and by adding single abnormal error and continuous abnormal error in observed value, test the resistant ability of algorithm to different abnormal errors. Simulation shows that the proposed algorithm can weaken the influence of abnormal error on position estimation, and can improve the efficiency of positioning based on F distribution discriminant algorithm.

To realize the voice privacy between CDMA mobile phone and PSTN terminal, the voice frames shall be transmitted transparently between the heterogeneous networks. For satisfying this requirement, we propose the method which transmits voice frames by the CDMA circuit data channel in real time. In this paper we analyze the causes of voice delay which occurs during voice transmission by circuit data channel, propose methods which overcome the voice transmission delay and prove proposed methods by the experiment.

최근 휴대단말기는 다양한 기능이 첨가되고 슬림화와 소형화 추세에 따라 내장형 안테나의 수납공간이 더욱 협소해지고 있다. 또 안테나가 복잡한 부품으로 둘러싸인 단말기 내부의 좁은 공간에 수납됨으로서 대역폭 확보가 어렵고 임피던스가 낮아지게 된다. 게다가 주변의 부품들에 의한 편파 손실이 추가됨으로써 낮은 효율로 인해 원하는 안테나 이득을 발생시키는데 어려움이 따른다. IFA는 모노폴 안테나를 변형시킨 ILA(Inverted L Antenna)를 기본으로 하는 낮은 프로파일(low profile) 구조의 안테나로, 휴대폰 내장형 안테나에 적합한 여러 장점을 가지고 있으나 모노폴 안테나에 비해 이득이 떨어지고 대역폭이 좁은 단점을 가지고 있다. 본 논문에서는 커플링 급전 구조를 사용한 블레이드 하이브리드 안테나를 제안한다.

In recent years mobile phone handset terminal has tended to have additional various functions and slim and light weight, and its internal space is getting smaller and narrower. According to complex parts, small and narrow inner space is caused not sufficient bandwidth and lower impedance. Moreover, additional polarization loss by the surrounding parts produces is lower effectiveness and increases difficulties for getting the antenna gain. For IFA is low profile structure based on the ILA(Inverted L Antenna) which is transformed from the monople antenna. While this antenna has lots of advantages in internal antenna of mobile phone, it has some disadvantage of reduced bandwidth and gains compared with monopole antenna. In this paper, propose vlade hybrid antenna use for the coupling structure.

근래에 이르러 Digital Photo에 대한 사용자들의 수요가 늘어나면서 DSC이나 Camera Phone으로부터 Photo용 Printer로의 Printing Solution 개발에 대한 요구가 증가하고 있다. 2003년에 미국과 일본의 회사들이 이런 용도로 PictBridge를 개발하였다. 이것은 Image File의 전송에 대한 것인데, 최근에 이르러 양질의 프린팅 서비스 제공을 위하여 XHTML을 전송하는 방식에 대한 연구가 진행 중이다. 본 논문은 Pictsridge 상에 HXHTML script을 전송하는 방식에 대한 내용을 담고 있다.

The mobile terminal system plays a key role in medical industries which require in fast and accurate diagnosis from heterogeneous acquisition equipment. The demand for PACS (picture archiving and communication systems) has continued to increase in major hospitals and private clinics. Patient care depends on how fast the medical imaging system provides images and how accurately the images are interpreted by physicians. In this paper, we propose an efficient method to decipher the hundreds of images required by physicians to accurately diagnose patients. By exploring Motion- JPEG (M-JPEG), this paper has demonstrates the possibilities for efficient management of medical images with a newly designed image file format and improvement in imaging diagnoses through the replaying of moving pictures of a patient in a mobile environment.

In this paper, presents the design of mobile field robot controlled by microcomputer. The computer works as the supervisory system for decision making and sending command to control the field robot. An information from encoder, infrared sensors using for control task of the robot that can be interconnected with the computer through the serial communication RS422 standard. In this case, the user can design the program algorithm base on microcomputer in order to control and define the routing of the mobile robot. Moreover, the robot can be installed other equipment fer collect data such as picture, sound, temperature etc., in order to working in the dangerous area.

A promising approach to improve the performance of mobile location system is the use of antenna arrays in both transmitter and receiver sides. Using advanced array signal processing techniques, such multiple-input multiple-output (MIMO) communication systems can offer more mobile location information by exploiting the spatial properties of the multipath channel. In this paper, we propose a novel approach to determine the position of mobile terminal based on estimated multipath signal parameters using only one base station in MIMO communication systems. This approach intends to minimize the error occurring from the estimation of multiple paths and gives an optimal estimation of the position of mobile terminal by simultaneously calculating a set of nonlinear location equations. This solution breaks the bottleneck of conventional mobile location systems which have to require multilateration of at least three base stations.

For the sake of the potential ability of overcoming interference in TD-SCDMA(time division-synchronous code division multiple access) systems, pilot signal is adopted, but the presented TD-SCDMA protocol has not considered the Rake technique for their mobile terminals. This paper developed a RAKE receiver algorithm and an implementation circuit, which make use of the pilot signal in the burst structure of the TD-SCDMA base station to estimate main channel parameter(channel delays) in the downlink of TD-SCDMA wireless network. The algorithm can reduce multipath interference for the mobile units in multiusers' case. Theoretic performance analysis presented in the paper and computer simulations show that there is a range of BER for Rake receiver and confirm that the proposed RAKE receiver algorithm achieved a better performance under multipath fading propagation and multiusers conditions.

Traditional voice traffic over mobile communication has been changed into data and media contents traffic, which makes traffic amount increases and speedy data transfer required. In the near future ubiquitous mobile terminal environment will be common so that security issues will arise due to many heterogeneous equipments and connections. In this paper, many previous methods used for terminal authentication are examined. And we propose new system model which uses our novel user authentication protocol based on strong one-time password (OTP) and short message service (SMS). We verify our system model and protocol by implementation.