Voltage controlled oscillators for 40Gbit/s cascaded bit-interleaving PON

Technologies such as the Internet-of-Things and cloud services demand dynamic bandwidth allocation flexibility, which is not offered by the currently deployed solutions. The Bit-Interleaving PON (BiPON) and its cascaded extension the Cascaded Bit-Interleaving PON (CBI-PON) offer a solution that allows to increase bandwidths, reduce power consumption and have a much more flexible dynamic bandwidth allocation scheme. CBI-PON consists of multiple levels of BiPON with different line rates. For each of these line rates, clock-and-data recovery must be performed, which requires a set of different Voltage Controlled Oscillators (VCOs). This paper presents the VCOs designed for the CABINET chip, an implementation of a CBI-PON network device, allowing clock-and-data recovery for 40Gbit/s, 10 Gbit/s and 2.5 Gbit/s line rates

The 40 Gbps cascaded bit-interleaving PON

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10 Gbit/s bit interleaving CDR for low-power PON

A novel, low power, downstream clock and data recovery (CDR)- decimator architecture is proposed for next generation, energy efficient 10 Gbit/s optical network units (ONUs). The architecture employs a new time division multiplexing bit-interleaving downstream concept for passive optical networks (Bi-PON) allowing early decimation of the incoming data and lowering of the processing speed to the user rate of the ONU, thus reducing the power consumption significantly

Energy-efficiency improvements for optical access

This article discusses novel approaches to improve energy efficiency of different optical access technologies, including time division multiplexing passive optical network (TDM-PON), time and wavelength division multiplexing PON (TWDM-PON), point-to-point (PTP) access network, wavelength division multiplexing PON (WDM-PON), and orthogonal frequency division multiple access PON (OFDMA-PON). These approaches include cyclic sleep mode, energy-efficient bit interleaving protocol, power reduction at component level, or frequency band selection. Depending on the target optical access technology, one or a combination of different approaches can be applied

A low power 40 Gbit/s cascaded extension to bit-interleaving optical networks enabling next-generation metro/access connectivity

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Evidence-based urology in practice : heterogeneity in a systematic review meta-analysis

The definitive version is available at www3.interscience.wiley.com.Peer reviewedPreprin

University classes during the state of emergency in Serbia introduced after the outbreak of the COVID-19 pandemic crisis: Students’ attitudes

У Србији је током пролећа 2020. године било уведено ванредно стање због пандемије нове болести COVID-19. Као последица тога по први пут је на универзитетима у Србији почела да се одвија настава на даљину, и то онлајн настава у сасвим специфичним кризним околностима проузрокованим избијањем пандемије потпуно непознате инфективне болести. Тој чињеници је и овај модел наставе био прилагођен, као хитна настава на даљину. У стицања знања у пракси која се не могу виртуелно компензовати, што је веома важан корак у њиховом радном оспособљавању, као и изражен генерални проблем недостатка социјалне интеракције и задовољења друштвених потреба, настао као последица пандемије COVID-19. Насупрот томе, повећање слободног времена и здравствени разлози се истичу као основне предности примењеног модела наставе, чија је битна карактеристика кризно окружење. раду су приказни резултати испитивања ставова студенткиња учитељских факултета у Србији у вези са ефикасношћу и одрживошћу модела наставе на даљину у односу на који су стекле искуства. Узорком је чинило 399 студенткиња, које су онлајн попуњавале анкету конструисану за потребе овог истраживања. Резултати спроведене анкете су показали предности и недостатке учења на даљину као до тада неупотријебљеног потенцијала у високом школству у Србији, што се специфично односи на модел наставе који је примењен у време ванредног стања уведеног због пандемије узроковане вирусом COVID-19. Такође, разлике у познавању дигиталних технологија од стране професора су дошле до изражаја у погледу метода које су професори користили у свом раду. Резултати упућују на закључак да настава на даљину може бити користан алат у процесу трансфера знања у високом школству, али и да су студенткиње завршних година највише погођене немогућношћуThe state of emergency was declared in Serbia in the spring of 2020 due to the pandemic of the new disease, COVID–19. As a result, distance learning was introduced for the first time at Serbian universities – online learning in utterly specific crisis circumstances caused by the outbreak of the pandemic of a completely unknown infectious disease. This model of learning was adjusted to that fact in the form of emergency remote teaching. The paper presents the results of examining the attitudes of female students of teacher education faculties in Serbia regarding the efficiency and sustainability of the distance learning model in which they gained experience. The sample included 399 female students, who completed an online survey designed for the purposes of this research. The results of the survey showed the strengths and weaknesses of distance learning as a formerly untapped potential in higher education in Serbia, which specifically refers to the teaching model applied during the state of emergency introduced due to the crisis caused by the COVID–19 pandemic. Also, the differences in the knowledge of digital technologies by the professors came to the fore in terms of the methods that the professors used in their work. The results suggest that distance learning can be a useful tool in the process of knowledge transfer in higher education, but that final year students are most affected by the inability to acquire knowledge in practice that cannot be virtually compensated, which is a very important step in their work training, as well as the pronounced general problem of lack of social interaction and meeting social needs, arising as a result of the pandemic. In contrast, increased leisure time and health reasons stand out as the main advantages of the new teaching model, which is significantly characterized by the crisis environment

A low-energy rate-adaptive bit-interleaved passive optical network

Energy consumption of customer premises equipment (CPE) has become a serious issue in the new generations of time-division multiplexing passive optical networks, which operate at 10 Gb/s or higher. It is becoming a major factor in global network energy consumption, and it poses problems during emergencies when CPE is battery-operated. In this paper, a low-energy passive optical network (PON) that uses a novel bit-interleaving downstream protocol is proposed. The details about the network architecture, protocol, and the key enabling implementation aspects, including dynamic traffic interleaving, rate-adaptive descrambling of decimated traffic, and the design and implementation of a downsampling clock and data recovery circuit, are described. The proposed concept is shown to reduce the energy consumption for protocol processing by a factor of 30. A detailed analysis of the energy consumption in the CPE shows that the interleaving protocol reduces the total energy consumption of the CPE significantly in comparison to the standard 10 Gb/s PON CPE. Experimental results obtained from measurements on the implemented CPE prototype confirm that the CPE consumes significantly less energy than the standard 10 Gb/s PON CPE

CBI: a scalable energy-efficient protocol for metro/access networks

This paper presents a scalable energy-efficient MAC/PHY protocol for building a metro/access network. The proposed cascaded bit-interleaving (CBI) protocol extends the previously reported bit-interleaving concept to a multi-level paradigm. Moreover, a 40Gb/s 3-level electrical duobinary based physical layer scheme has been proposed for cost and energy saving, especially for end terminals. We compared two implementation approaches in terms of optical budget and transmission penalties. The initial estimate from the proof-ofconcept full-custom ASIC design shows that an ultra-low power metro/access network can be realized

"Drop in" gastroscopy outpatient clinic - experience after 9 months

<p>Abstract</p> <p>Background</p> <p>Logistics handling referrals for gastroscopy may be more time consuming than the examination itself. For the patient, "drop in" gastroscopy may reduce uncertainty, inadequate therapy and time off work.</p> <p>Methods</p> <p>After an 8-9 month run-in period we asked patients, hospital staff and GPs to fill in a questionnaire to evaluate their experience with "drop in" gastroscopy and gastroscopy by appointment, respectively. The diagnostic gain was evaluated.</p> <p>Results</p> <p>112 patients had "drop in" gastroscopy and 101 gastroscopy by appointment. The number of "drop in" patients varied between 3 and 12 per day (mean 6.5). Mean time from first GP consultation to gastroscopy was 3.6 weeks in the "drop in" group and 14 weeks in the appointment group. The half-yearly number of outpatient gastroscopies increased from 696 before introducing "drop in" to 1022 after (47% increase) and the proportion of examinations with pathological findings increased from 42% to 58%. Patients and GPs expressed great satisfaction with "drop in". Hospital staff also acclaimed although it caused more unpredictable working days with no additional staff.</p> <p>Conclusions</p> <p>"Drop in" gastroscopy was introduced without increase in staff. The observed increase in gastroscopies was paralleled by a similar increase in pathological findings without any apparent disadvantages for other groups of patients. This should legitimise "drop in" outpatient gastroscopies, but it requires meticulous observation of possible unwanted effects when implemented.</p