64-GHz millimeter-wave photonic generation with a feasible radio over fiber system

Copyright 2017 Society of Photo‑Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.A full-duplex radio over fiber (RoF) link with the generation of a 64-GHz millimeter wave (mm-wave) is investigated. This system is proposed as a solution to cope with the demands of a multi-Gb/s data transmission in the fifth generation (5G) and beyond for small cell networks. Cost reduction and performance improvement are achieved by simplifying the mm-wave generation method with an RoF technique. High-frequency radio signals are considered challenging in the electrical generation domain; therefore, our photonic generation method is introduced and examined. RoF design is proposed for mm-wave generation using both phase modulation and the effect of stimulated Brillouin scattering in the optical fiber for the first time. RoF system with transmission rates of 5 Gb/s is successfully achieved. In our scheme, one laser source is utilized and a fiber Bragg grating is used for wavelength reuse for the uplink connection. Stable mm-wave RoF link is successfully achieved in up to a 100-km fiber link length with high quality carrier. Simulation results show a reduction in fiber nonlinearity effects and the mm-wave signal has low noise equal to -75 dBm. This study ensures a practical mm-wave RoF link, and it could be appropriate for small cell 5G networks by reducing the installation cost

Iraqi health system in kurdistan region: medical professionals' perspectives on challenges and priorities for improvement

<p>Abstract</p> <p>Background</p> <p>The views of medical professionals on efficiency of health system and needs for any changes are very critical and constitute a cornerstone for any health system improvement. This is particularly relevant to Iraqi Kurdistan case as the events of the last few decades have significantly devastated the national Iraqi health system while the necessity for adopting a new health care system is increasingly recognized since 2004. This study aims to examine the regional health system in Iraqi Kurdistan from medical professionals' perspectives and try to define its problems and priorities for improvement.</p> <p>Methods</p> <p>A survey questionnaire was developed and administered to a convenience sample of 250 medical professionals in Erbil governorate. The questionnaire included four items; rating of the quality of services and availability of resources in the health institutions, view on different aspects of the health system, the perceived priority needs for health system improvement and gender and professional characteristics of the respondents.</p> <p>Results</p> <p>The response rate to the survey was 83.6%. A high proportion of respondents rated the different aspects of services and resources in the health institutions as weak or very weak including the availability of the required quantity and quality of medicines (68.7%), the availability of sufficient medical equipment and investigation tools (68.7%), and the quality of offered services (65.3%). Around 72% of respondents had a rather negative view on the overall health system. The weak role of medical research, the weak role of professional associations in controlling the system and the inefficient health education were identified as important problems in the current health system (87.9%, 87.1% and 84.9%, respectively). The priority needs of health system improvement included adoption of social insurance for medical care of the poor (82%), enhancing the role of family medicine (77.2%), adopting health insurance system (76.1%) and periodic scientific evaluation of physicians and other health staff (69.8%).</p> <p>Conclusion</p> <p>Medical professionals were generally unsatisfied with the different aspects of the health system in Iraqi Kurdistan region. A number of problems and different priority needs for health system improvement have been recognized that require to be studied in more details.</p