Preliminary performance evaluation and verification of digital terrestrial television signal propagation

This article presents the computer simulation and field test measurement results on Channel 29 for the preliminary performance evaluation and verification of the newly-installed Lesotho digital terrestrial television network based on DVB-T2 standard following the guidelines and techniques specified by the ITU-R BT.2035-2. It evaluates, at predetermined outdoor locations for fixed and mobile reception, parameters such as received signal strength, signal quality, bit-error rate (BER) and threshold-of-visibility (ToV) together with TV signal decoding (observation of screen artefacts) for quasi error-free reception. The results indicate that at over 97% of the test sites/points at the university town of Roma, the main Berea Plateau transmitter from the capital city (Maseru) broadcasts digital television service with enough signal level and quality to be properly decoded. The measured signal strength threshold ranges above -50 dBm for good reception, -64 dBm to -50 dBm for acceptable reception and -69 dBm to -64 dBm for poor reception. With the noise floor at about -73 dBm, the minimum required C/N of around 23 dB for good reception and about 4 dB for ToV have been recorded. The relative values of minimum required respective signal strength and signal quality for ToV obtained from the set-top box are 33% and 18% for stationary reception, while they give 37% and 20% for mobile reception.

Eavesdropping Vulnerability and Countermeasure in Infrared Communication for IoT Devices

Infrared (IR) communication is one of the wireless communication methods mainly used to manipulate consumer electronics devices. Traditional IR devices support only simple operations such as changing TV channels. These days, consumer electronic devices such as smart TV are connected to the internet with the introduction of IoT. Thus, the user’s sensitive information such as credit card number and/or personal information could be entered with the IR remote. This situation raises a new problem. Since TV and the set-top box are visual media, these devices can be used to control and/or monitor other IoT devices at home. Therefore, personal information can be exposed to eavesdroppers. In this paper, we experimented with the IR devices’ reception sensitivity using remotes. These experiments were performed to measure the IR reception sensitivity in terms of distance and position between the device and the remote. According to our experiments, the transmission distance of the IR remote signal is more than 20 m. The experiments also revealed that curtains do not block infrared rays. Consequently, eavesdropping is possible to steal the user’s sensitive information. This paper proposes a simple, practical, and cost-effective countermeasure against eavesdropping, which does not impose any burden on users. Basically, encryption is used to prevent the eavesdropping. The encryption key is created by recycling a timer inside the microcontroller typically integrated in a remote. The key is regenerated whenever the power button on a remote is pressed, providing the limited lifecycle of the key. The evaluation indicates that the XOR-based encryption is practical and effective in terms of the processing time and cost.

Reducing Buffering Delay Using Memory Arbitration Mechanism for IPTV Based Applications

High-speed communication needs high data transfer capacity and low latency, which are the key parameters of high-speed communication. Converging different applications such as IPTV to high-speed networks requires high transmission capacity and low delay with good QoS. Delays related to IPTV are video buffering, synchronization, and switching delay that obstructs the client's excellent quality assistance. In an application like IPTV, the video signals are buffered (happened to be in near end routers), and they are recombined for the client when it is asserted. To achieve the above stated, memory banks are deployed in a set top box that is used to buffer the video signals that enter in, thereby reducing expected delay. Playback mechanism is also included along with the proposed model to accomplish a better outcome. Proposed RTL schematic design was simulated using Verilog, executed in Model Sim – Altera 10.1b (Quartus II 12.1 edition) and Cadence 5.

X-ray determination and modeling of macro-stresses in products

The operating conditions of modern equipment are often rather severe and the materials used for production are exposed to extremely high temperatures and force effects resulting in formation of increased macro-stresses the level of which should be controlled. We present the results of x-ray determination of macro-stresses. Flat specimens made of steel 20 were tested using a diffractometer supplemented with a small two — circle goniometer. Using a set-top box mounted on the proper site of the unit attachment, the object under control was rotated to provide implementation of the applied x-ray method sin2ψ. To simulate the processes which affect the level and distribution of stresses in the product (e.g., drilling, local heating, etc.), the attachment is equipped with a small-sized loading device. In addition to forming macro-stresses of a given value in the sample, the device provided control of the stress distribution over the product. The proposed technical solution can be used in developing a «check specimen», since the use of standard macro-stress samples faces known difficulties. In this case, the macro-stresses of a required level are formed in the specimen made of the same material (or directly of the product) using the loading device of the attachment to compare the results of measurements with the data of product testing.

Implementasi Sistem Siaran Televisi Digital Di Lpp Tvri Stasiun Jawa Tengah

Implementasi sistem siaran televisi digital tidaklah mudah, ada beberapa kendala seperti ketidaksiapan masyarakat dalam mengadopsi sistem baru, infrastruktur sistem penerimaan dan pesawat unit televisi harus diganti, serta menambah peralatan Set Top Box. Tujuan penelitian ini untuk mengetahui implementasi sistem siaran televisi digital di LPP TVRI Stasiun Jawa Tengah. Penelitian ini menggunakan metode deskriptif kualitatif, dengan teknik pengumpulan data observasi dan wawancara. Hasil penelitian LPP TVRI Stasiun Jawa Tengah mendapatkan subsidi infrastruktur yang berupa pemancar atau transmisi digital pada tahun 2013 dari Menkominfo dengan type UHF BT-ESA (DVB-T2), Merk RS dengan kekuatan pancar 5 KW. LPP TVRI Stasiun Jawa Tengah sebagai penyedia infrastruktur dalam sistem siaran televisi digital sangat mendukung dan sudah menyatakan siap untuk beralih ke sistem digital. Hasil uji coba siaran digital belum bisa menjangkau semua wilayah masyarakat Jawa Tengah, karena terkendala infrastruktur dan SDM. Hal tersebut disebabkan karena belum ada regulasi atau kebijakan pemerintah dari payung hukum, infrastruktur yang memadai, hak publik, dan harga pesawat televisi berformat DVB-T2 yang mahal. Penelitian ini memberikan rekomendasi kepada pemerintah untuk memberikan subsidi terhadap pengadaan setup box TV digital agar seluruh daerah di Jawa Tengah terjangkau siaran digital, serta memberikan pelatihan kepada SDM yang mengoperasikan perangkat TV digital.

Aplicação do Jidoka em um processo SMT: estudo de caso

Produção com qualidade é assunto crítico em qualquer processo, mais especialmente em processos cujo recurso predominante seja o uso de máquinas, as quais caso não estejam ajustadas ou capacitadas a detectar falhas, podem contribuir para altos custos de desperdício de defeitos em série, seja pelo reprocesso ou pelo refugo de produtos não conformes. O objetivo deste artigo é apresentar um estudo de caso na aplicação do Jidoka em um processo de Surface Mount Technology (SMT), essa ferramenta foi usada para direcionar ações que contribuíram na detecção e eliminação de defeitos de set top box sem vídeo. A pesquisa foi aplicada em uma empresa multinacional do Polo Industrial de Manaus (PIM). A metodologia foi guiada pelo Define, Measure, Analyze, Improve and Control (DMAIC). Como resultados, a ferramenta se mostra adequada para este tipo de processo, ganho financeiro foi evidenciado, além da redução significativa de problemas no produto final.