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Seok J.M.,Broadcasting and Telecommunications Media Research Laboratory | Lee Y.,Agency for Defense Development
ETRI Journal

In the near future, traditional narrow and fixed viewpoint video services will be replaced by high-quality panorama video services. This paper proposes a visualattention-aware progressive region of interest (RoI) trick mode streaming service (VA-PRTS) that prioritizes video data to transmit according to the visual attention and transmits prioritized video data progressively. VA-PRTS enables the receiver to speed up the time to display without degrading the perceptual quality. For the proposed VA-PRTS, this paper defines a cutoff visual attention metric algorithm to determine the quality of the encoded video slice based on the capability of visual attention and the progressive streaming method based on the priority of RoI video data. Compared to conventional methods, VA-PRTS increases the bitrate saving by over 57% and decreases the interactive delay by over 66%, while maintaining a level of perceptual video quality. The experiment results show that the proposed VA-PRTS improves the quality of the viewer experience for interactive panoramic video streaming services. The development results show that the VA-PRTS has highly practical real-field feasibility. © 2014 ETRI. Source

Lee K.-H.,Pai Chai University | Lee H.-W.,Broadcasting and Telecommunications Media Research Laboratory | Han Y.-H.,Korea University of Technology and Education
International Journal of Multimedia and Ubiquitous Engineering

This paper proposes a new IPv4/IPv6 traversal scheme based on a scalable network-based IP mobility management system, called Access Independent Mobile Service (AIMS), which can provide MNs with high-quality mobility services over various wireless access networks. The proposed AIMS with IPv4/IPv6 Dual Stack Support (AIMS-DS) scheme can support an MN moving continuously across the IPv4/IPv6 coexisting networks by IPv4/IPv6 address binding and dynamic transport control based on the IP-in-IP tunnel method. It inherits the novel features of the AIMS system including complete separation control and data planes in the core network and cross-layer (layer2 and 3) interworking method for handover control optimization. The performance evaluation results from our simulation study show that the proposed scheme properly handles a dual stack MN's handovers across IPv4/IPv6 coexisting networks. It is also shown that the proposed scheme outperforms the existing approach in some performance factors including packet delivery latency and handover latency. © 2014 SERSC. Source

Jeong J.-C.,Broadcasting and Telecommunications Media Research Laboratory | Jang D.-P.,Broadcasting and Telecommunications Media Research Laboratory | Han B.-G.,Radar Corporation | Yom I.-B.,Broadcasting and Telecommunications Media Research Laboratory
ETRI Journal

A C-band 50 W high-power microwave monolithic integrated circuit amplifier for use in a phased-Array radar system was designed and fabricated using commercial 0.25 μm AlGaN/GaN technology. This two-stage amplifier can achieve a saturated output power of 50 W with higher than 35% power-Added efficiency and 22 dB small-signal gain over a frequency range of 5.5 GHz to 6.2 GHz. With a compact 14.82 mm2 chip area, an output power density of 3.2 W/mm2 is demonstrated. © 2014 ETRI. Source

Chung T.J.,Broadcasting and Telecommunications Media Research Laboratory | Lee W.-H.,Broadcasting and Telecommunications Media Research Laboratory
ETRI Journal

A 10-Gbit/s wireless communication system operating at a carrier frequency of 300 GHz is presented. The modulation scheme is amplitude shift keying in incoherent mode with a high intermediate frequency (IF) of 30 GHz and a bandwidth of 20 GHz for transmitting a 10-Gbit/s baseband (BB) data signal. A single sideband transmission is implemented using a waveguide-tapered 270-GHz highpass filter with a lower sideband rejection of around 60 dB. This paper presents an all-electronic design of a terahertz communication system, including the major modules of the BB and IF band as well as the RF modules. The wireless link shows that, aided by a clock and data recovery circuit, it can receive 27-1 pseudorandom binary sequence data without error at up to 10 Gbit/s for over 1.2 m using collimating lenses, where the transmitted power is 10 μW. © 2013 ETRI. Source

Kang K.-M.,Broadcasting and Telecommunications Media Research Laboratory | Park J.,Broadcasting and Telecommunications Media Research Laboratory
IEEE Transactions on Consumer Electronics

This paper presents a cognitive radio system (CRS) that complies with the maximum allowable transmit power and emission limits of TV band devices (TVBDs). The CRS consists of a TVBD that uses the existing Wi-Fi module and two Wi-Fi modules operating in the 2.4 GHz and 5 GHz bands. Design methods are proposed for a radio frequency (RF) module, a digital signal processing (DSP) module, and a circuit for transmit-receive mode switching in the TV band device (TVBD). The performance of the implemented TVBD is investigated in both wired and wireless environments. The measured data rates of the implemented TVBD at the application layer are approximately 60 % of the theoretical data rates at the physical layer in the Wi-Fi system. The service coverage of a TVBD network is also measured according to several modulation and coding schemes (MCSs) of the TVBD for a single spatial stream. The coverage measurements of a TVBD network are conducted in both a suburban area, Jeju Island, and a nearly open area, Incheon, South Korea. The results show that the service coverage of a mobile network in TV white space (TVWS) can be enlarged by more than 2 km in the suburban area and by more than 8 km in the nearly open area. © 2015 IEEE. Source

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