Journal articles: 'Optical Line Terminal (OLT)'

1

Abbas, Huda Saleh, and Mark A. Gregory. "Passive Optical Network Survivability: Protection, Detection and Restoration." International Journal of Information, Communication Technology and Applications 1, no. 1 (March 9, 2015): 128–42. http://dx.doi.org/10.17972/ajicta20151115.

Full text

Abstract:

Passive optical network (PON) technologies have received increasing attention as demand for fibre access networks has grown. Enhancing fibre access network reliability provides lower operational costs, and improves customer satisfaction. This paper discusses PON survivability including protection schemes for the fiber link and the Optical Line Terminal (OLT), the exciting monitoring techniques of the fiber link, and the effect of reducing the restoration time on the network availability. The main contribution of this study is to provide two protection schemes namely OLT-only-protected and OLT-and-ring protected. The proposed schemes are designed to handle instances of single failure affecting all customers in the network. This work considers three key performance metrics- Failure Impact Robustness (FIR), cost, and availability. The objective of the proposed protection architectures is to guarantee high quality of service at low costs by protecting critical network elements such as OLT and fiber ring. The proposed architectures have been compared with other well-known protection schemes. The results postulate that OLT-and-ring protected approach has 99.993% availability with a 0.09% increase in cost compared to the ring-only protection architecture.

APA, Harvard, Vancouver, ISO, and other styles

2

Salleh, M. S., A. S. M. Supa’at, S. M. Idrus, S. Yaakob, and Z. M. Yusof. "Wavelength Tuning Free Transceiver Module in OLT Downstream Multicasting4λ × 10 Gb/s TWDM-PON System." Journal of Computer Networks and Communications 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/483249.

Full text

Abstract:

We propose a new architecture of dynamic time-wavelength division multiplexing-passive optical network (TWDM-PON) system that employs integrated all-optical packet routing (AOPR) module using4λ×10 Gbps downstream signal to support 20 km fiber transmission. This module has been designed to support high speed L2 aggregation and routing in the physical layer PON system by using multicasting cross-gain modulation (XGM) to route packet from any PON port to multiple PON links. Meanwhile, the fixed wavelength optical line terminal (OLT) transmitter with wavelength tuning free features has been designed to integrate with the semiconductor optical amplifier (SOA) and passive arrayed waveguide grating (AWG). By implementing hybrid multicasting and multiplexing, the system has been able to support a PON system with full flexibility function for managing highly efficient dynamic bandwidth allocation to support the4λ×10 Gb/s TWDM-PON system used to connect 4 different PON links using fixed wavelength OLT transceivers with maximum 38 dB link loss.

APA, Harvard, Vancouver, ISO, and other styles

3

Zhang, Chun Lei, Cai Hua Yan, and Hai Ling Chen. "Integrated Wireless and Wired Signal in the Hybrid Access System." Applied Mechanics and Materials 303-306 (February 2013): 2058–61. http://dx.doi.org/10.4028/www.scientific.net/amm.303-306.2058.

Full text

Abstract:

To meet the demands of different high bandwidth services, we demonstrated a hybrid access network simultaneously transmitting wired and wireless signals. In the downstream, wireless signals are modulated and transmitted in phase modulation format at the optical carrier and wired signals are re-modulated in intensity modulation format, different de-modulation schemes are used at optical network unit (ONU) side; In the upstream, carrier reuse technology are adopted to re-modulate and transmit uplink signals to the optical line terminal (OLT). Simulation results show user ends could get acceptable performance of the wirless and wired signals.

APA, Harvard, Vancouver, ISO, and other styles

4

Kang, Wen Hui, Xiao Hang Huang, Shi Cai Zhang, and Xiao Yuan Zhang. "Realization of RIP Module on GPON OLT System." Advanced Materials Research 989-994 (July 2014): 4962–65. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.4962.

Full text

Abstract:

As networks to be flattened, a direction has been put forward clearly by Telecom operators that Optical Line Terminals (OLT) of Gigabit Passive Optical Network (GPON) should become aggregation [1] OLTs, which makes them to work as both aggregation switches and edge access devices. According to this requirement, a scheme that realizes Routing [2] Information Protocol (RIP) on GPON OLT is put forward after deep analysis of GPON system [3] [4] [5] and RIP. Results shows that IP routing on GPON OLT is realized, which allows OLTs to work on the network layer, at the same time simplifies the broadband network levels and increases the reliability of the network.

APA, Harvard, Vancouver, ISO, and other styles

5

Yeh, Bih-Chyun. "Noncoherent Spectral Optical CDMA System Using 1D Active Weight Two-Code Keying Codes." Mathematical Problems in Engineering 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/3724843.

Full text

Abstract:

We propose a new family of one-dimensional (1D) active weight two-code keying (TCK) in spectral amplitude coding (SAC) optical code division multiple access (OCDMA) networks. We use encoding and decoding transfer functions to operate the 1D active weight TCK. The proposed structure includes an optical line terminal (OLT) and optical network units (ONUs) to produce the encoding and decoding codes of the proposed OLT and ONUs, respectively. The proposed ONU uses the modified cross-correlation to remove interferences from other simultaneous users, that is, the multiuser interference (MUI). When the phase-induced intensity noise (PIIN) is the most important noise, the modified cross-correlation suppresses the PIIN. In the numerical results, we find that the bit error rate (BER) for the proposed system using the 1D active weight TCK codes outperforms that for two other systems using the 1D M-Seq codes and 1D balanced incomplete block design (BIBD) codes. The effective source power for the proposed system can achieve −10 dBm, which has less power than that for the other systems.

APA, Harvard, Vancouver, ISO, and other styles

6

Hwang, I.-Shyan, Jhong-Yue Lee, and Zen-Der Shyu. "A Novel Dynamic Bandwidth Allocation Mechanism for Star-Ring-Based EPON." ISRN Communications and Networking 2011 (April 27, 2011): 1–9. http://dx.doi.org/10.5402/2011/837453.

Full text

Abstract:

Ethernet Passive Optical Network (EPON) is proposed as a simple, cost-effective and scalable solution for bandwidth bottlenecks in access networks which can enhance the system performance because it transmits the aggregated high-speed traffic from hundreds of subscribers. Dynamic Bandwidth Allocation (DBA) mechanism has not yet been seriously considered for use in star-ring EPON architecture. In this paper, a distributed QoS-based dynamic bandwidth allocation (DQ-DBA) scheduling mechanism for the star-ring-based EPON architecture including optical line terminal (OLT), Sub-OLT and ONUs has been proposed to improve the system performance of traditional tree-based EPON architecture. In DQ-DBA, the highest-priority traffic of each ONU is directed to the OLT by the tree structure; moreover, the lower-priority traffic on each ONU is transmitted to the Sub-OLT by ring architecture. This approach can effectively resolve the idle period problem and reduce the overloading of OLT in conventional DBA mechanisms. Exhaustive simulation experiments are performed to compare the system performance between the tree and the star-ring architectures and validate the effectiveness of the proposed mechanism. Simulation results show that the proposed DQ-DBA mechanism in star-ring architecture can reduce packet delay and jitter for the high-priority traffic, thus ensuring the quality of service (QoS) regardless of subscriber numbers.

APA, Harvard, Vancouver, ISO, and other styles

7

Usman, Auwalu, Nadiatulhuda Zulkifli, Mohd Rashidi Salim, and Kharina Khairi. "AN ENHANCED G-PON FAULT MONITORING TECHNIQUE USING OPTICAL SENSOR." Science Proceedings Series 1, no. 2 (April 24, 2019): 39–42. http://dx.doi.org/10.31580/sps.v1i2.621.

Full text

Abstract:

In this study a technique for a centralized fault monitoring and detection in Gigabit-capable Passive Optical Network (G-PON) using fiber Bragg grating (FBG) sensor is proposed. The technique detects fault once it occurs at the vulnerable locations in the fiber optic distribution link by the proposed FBG devices. Monitoring signal in the C-band is reflected by a uniform FBG with different Bragg wavelengths and reflectivities. The FBGs serve as branch identifiers in the network. The reflected signal from the FBGs is analyzed at the Optical Line Terminal (OLT) in the Central Office (CO) by an Optical Spectrum Analyzer (OSA), to identify the branch with rupture in the network. The simulated result obtained shows that the system can monitor, and detect a fault in the physical layer of the optical distribution network with negligible effects on data signal transmission.

APA, Harvard, Vancouver, ISO, and other styles

8

Butt, Rizwan A., Sevia M. Idrus, Shahid-Ur Rehman, Pir Meher Ali Shah, and Nadiatulhuda Zulkifli. "Comprehensive Polling and Scheduling Mechanism for Long Reach Gigabit Passive Optical Network." Journal of Optical Communications 40, no. 1 (January 28, 2019): 55–66. http://dx.doi.org/10.1515/joc-2017-0026.

Full text

Abstract:

Abstract Dynamic bandwidth assignment (DBA) schemes for long reach PONs face a suffer from higher upstream channel idle time due to long round trip time (RTT). In ITU PONs, the DBA schemes; Immediate allocation with colorless grant (IACG), Efficient bandwidth utilization (EBU) and GPON redundancy eraser algorithm (GREAL) minimize idle time by sending bandwidth grants to the optical network units (ONUs) every downstream frame (DF). EBU further improves IACG by utilizing unused bandwidth (UBW) of other traffic classes. Sending the grant results every DF requires optical line terminal (OLT) to remember all previous grants sent to ONU during RTT and subtract them from the received queue reports. Since, both IACG and EBU assign the excess bandwidth equally to ONUs. Therefore, the OLT is actually not aware of the complete grant to each traffic class and thus do not subtract these completely from receiving reports. This leads to wastage of bandwidth and higher US delays due to over granting. GREAL resolves this problem by not utilizing the excess bandwidth which also leads to increased US delays. The proposed scheme in this study eliminates this shortcoming by allocating excess bandwidth to each traffic class completely at the OLT. Moreover, the UBW assignment mechanism of EBU is also improved. Simulation results show a 50–85 % reduction in delays of type-2 (T2) and type-3 (T3) traffic classes versus GREAL and IACG and up to 40 % reduction in delays for type-4 (T4) versus EBU.

APA, Harvard, Vancouver, ISO, and other styles

9

Chakraborty, Meenakshi, and Taraprasad Chattopadhyay. "A Novel Scheme for UDWDM-PON Broadband Access Network Using Injection-Locked Phase-to-Intensity Modulation Converter." Journal of Optical Communications 40, no. 4 (October 25, 2019): 369–77. http://dx.doi.org/10.1515/joc-2017-0085.

Full text

Abstract:

Abstract In this paper, we have proposed and analyzed a novel cost-effective ultradense wavelength division multiplexed (UDWDM) passive optical network (PON) which uses phase modulation (PM) of the optical carriers in the optical line terminal (OLT) in order to achieve inherent noise immunity in the network. In the demodulation of the optical PM signal at the optical network unit (ONU), we have proposed to use a simple injection–locked Fabry–Perot (FP) laser diode (LD) for achieving PM to intensity modulation (IM) converter which is followed by a photodiode to recover the specific channel information. A detailed analysis of PM–IM conversion in an injection–locked FPLD has been carried out and the viability of the proposed scheme has been established. The proposed UDWDM–PON which is a broadband access network is cost-effective and long reach.

APA, Harvard, Vancouver, ISO, and other styles

10

Radoš, Katarina, and Ivan Radoš. "Availability Analysis of Diﬀerent PON Models." Journal of Telecommunications and Information Technology 4 (December 20, 2017): 47–53. http://dx.doi.org/10.26636/jtit.2017.116517.

Full text

Abstract:

Due to the increasing demands of individual users, Passive Optical Networks (PON) are a promising technology for future broadband access networks. Reliable access to network services is a very important feature, so the availability of the connection is becoming one of the most important requirements. Failure of the optical ﬁber occurring between the Optical Line Terminal (OLT) and the passive optical splitter can cause the services becoming unavailable for a large number of users, so it is necessary to prevent such an occurrence by providing backup resources – in this case a spare optical ﬁber. When constructing the spare path (protection ﬁber), it is important to keep in mind that, if possible, the working and the spare ﬁber should not be positioned within the same cable. Failure of the optical ﬁber between the passive splitter and the individual user also means a loss of service for that user. In that case, protection may be oﬀered by adding spare ﬁbers. The question is, however, whether such a solution is cost-eﬀective, as it would lead to a signiﬁcant cost increase in the construction of the access network. This paper presents the availability analysis conducted for diﬀerent PON models.

APA, Harvard, Vancouver, ISO, and other styles

11

Cevik, Taner. "A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs." Scientific World Journal 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/561984.

Full text

Abstract:

One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand.

APA, Harvard, Vancouver, ISO, and other styles

12

Sankoh, Abdulai, Wei Jin, Zhuqiang Zhong, Jiaxiang He, Yanhua Hong, Roger Giddings, and Jianming Tang. "DFT-Spread Spectrally Overlapped Hybrid OFDM–Digital Filter Multiple Access IMDD PONs." Sensors 21, no. 17 (September 2, 2021): 5903. http://dx.doi.org/10.3390/s21175903.

Full text

Abstract:

A novel transmission technique—namely, a DFT-spread spectrally overlapped hybrid OFDM–digital filter multiple access (DFMA) PON based on intensity modulation and direct detection (IMDD)—is here proposed by employing the discrete Fourier transform (DFT)-spread technique in each optical network unit (ONU) and the optical line terminal (OLT). Detailed numerical simulations are carried out to identify optimal ONU transceiver parameters and explore their maximum achievable upstream transmission performances on the IMDD PON systems. The results show that the DFT-spread technique in the proposed PON is effective in enhancing the upstream transmission performance to its maximum potential, whilst still maintaining all of the salient features associated with previously reported PONs. Compared with previously reported PONs excluding DFT-spread, a significant peak-to-average power ratio (PAPR) reduction of over 2 dB is achieved, leading to a 1 dB reduction in the optimal signal clipping ratio (CR). As a direct consequence of the PAPR reduction, the proposed PON has excellent tolerance to reduced digital-to-analogue converter/analogue-to-digital converter (DAC/ADC) bit resolution, and can therefore ensure the utilization of a minimum DAC/ADC resolution of only 6 bits at the forward error correction (FEC) limit (1 × 10−3). In addition, the proposed PON can improve the upstream power budget by >1.4 dB and increase the aggregate upstream signal transmission rate by up to 10% without degrading nonlinearity tolerances.

APA, Harvard, Vancouver, ISO, and other styles

13

He, Chao, and Ruyan Wang. "A QoE-Aware Energy Supply Scheme over a FiWi Access Network in the 5G Era." Sensors 20, no. 13 (July 7, 2020): 3794. http://dx.doi.org/10.3390/s20133794.

Full text

Abstract:

Integrated fiber-wireless (FiWi) should be regarded as a promising access network architecture in future 5G networks, and beyond; this due to its seamless combination of flexibility, ubiquity, mobility of the wireless mesh network (WMN) frontend with a large capacity, high bandwidth, strong robustness in time, and a wavelength-division multiplexed passive optical network (TWDM-PON) backhaul. However, the key issue in both traditional human-to-human (H2H) traffic and emerging Tactile Internet is the energy conservation network operation. Therefore, a power-saving method should be instrumental in the wireless retransmission-enabled architecture design. Toward this end, this paper firstly proposes a novel energy-supply paradigm of the FiWi converged network infrastructure, i.e., the emerging power over fiber (PoF) technology instead of an external power supply. Then, the existing time-division multiplexing access (TDMA) scheme and PoF technology are leveraged to carry out joint dynamic bandwidth allocation (DBA) and provide enough power for the sleep schedule in each integrated optical network unit mesh portal point (ONU-MPP) branch. Additionally, the correlation between the transmitted optical power of the optical line terminal (OLT) and the quality of experience (QoE) guarantee caused by multiple hops in the wireless frontend is taken into consideration in detail. The research results prove that the envisioned paradigm can significantly reduce the energy consumption of the whole FiWi system while satisfying the average delay constraints, thus providing enough survivability for multimode optical fiber.

APA, Harvard, Vancouver, ISO, and other styles

14

Memon, Kamran, Khalid Mohammadani, Noor Ain, Arshad Shaikh, Sibghat Ullah, Qi Zhang, Bhagwan Das, Rahat Ullah, Feng Tian, and Xiangjun Xin. "Demand Forecasting DBA Algorithm for Reducing Packet Delay with Efficient Bandwidth Allocation in XG-PON." Electronics 8, no. 2 (January 31, 2019): 147. http://dx.doi.org/10.3390/electronics8020147.

Full text

Abstract:

In a typical 10G-Passive Optical Network (XG-PON), the propagation delay between the Optical Network Unit (ONU) and Optical Line Terminal (OLT) is about 0.3 ms. With a frame size of 125 μs, this amounts to three frames of data in the upstream and three frames of data in the downstream. Assuming no processing delays, the grants for any bandwidth requests reach the ONU after six frames in this request-grant cycle. Often, during this six-frame delay, the queue situation is changed drastically, as much, more data would arrive in the queue. As a result, the queued data that is delayed loses its significance due to its real-time nature. Unfortunately, almost all dynamic bandwidth allocation (DBA) algorithms follow this request-grant cycle and hence lacking in their performance. This paper introduces a novel approach for bandwidth allocation, called Demand Forecasting DBA (DF-DBA), which predicts ONU’s future demands by statistical modelling of the demand patterns and tends to fulfil the predicted demands just in time, which results in reduced delay. Simulation results indicate that the proposed technique out-performs previous DBAs, such as GigaPON access network (GIANT) and round robin (RR) employing the request-grant cycle in terms of Throughput and Packet delivery ratio (PDR). Circular buffers are introduced in statistical predictions, which produce the least delay for this novel DF-DBA. This paper, hence, opens up a new horizon of research in which researchers may come up with better statistical models to brew better and better results for Passive optical networks.

APA, Harvard, Vancouver, ISO, and other styles

15

Parajuli, Hum Nath, and Eszter Udvary. "Wired-Wireless Converged Passive Optical Network with 4-PAM and Multi-sub-bands FBMC." Infocommunications journal, no. 2 (2018): 1–6. http://dx.doi.org/10.36244/icj.2018.2.1.

Full text

Abstract:

Future 5G based passive optical networks (PON) are expected as capable of the simultaneous provision of wired and wireless services for multi-users. In this paper, for the first time, we propose and demonstrate the simultaneous delivery of wired 4-pulse amplitude modulation (4-PAM) and wireless multi-sub-bands filter bank multicarrier (FBMC) signals in one wavelength using one laser source for the future 5G PON. The 4-PAM can be used in cost-efficient intensity modulation direct detection (IM/DD) systems and it provides the double bandwidth efficiency compared to conventional on-off keying (OOK). FBMC is considered as a potential candidate for future wireless 5G due to its high suppression for out of band emissions, which allows combining multiple sub-bands with very narrow band-gaps. Using multi-sub-bands with a narrow band gap, the overall transmission capacity can be increased. In the designed system, the composite wired 4-PAM and wireless multi-sub-bands FBMC signal is generated and transmitted with intensity modulation in optical line terminal (OLT). In the optical network unit (ONU) the wired and wireless signals from the received composite signal are extracted using an electrical square band-pass filter and separately demodulated using digital signal processing techniques. The designed 4-PAM has baseband bandwidth of 4.8 GHz and multi-subbands FBMC consists of 4 sub-bands of 500 MHz each, having very narrow inter-sub-bands gap of 488.28 kHz and the aggregate bandwidth of 2.0015 GHz. The bit error rate (BER) has been evaluated for the performance analysis of the 4-PAM and multi-sub-bands FBMC for two cases (a) separate transmission and (b) composite transmission.

APA, Harvard, Vancouver, ISO, and other styles

16

Deepak, M. "A Study of Secured Enabled Passive Optical Network Enabling RoF." Indonesian Journal of Electrical Engineering and Computer Science 9, no. 1 (January 1, 2018): 43. http://dx.doi.org/10.11591/ijeecs.v9.i1.pp43-48.

Full text

Abstract:

Innovation is an incorporation of radio sign in optical fiber transmission inside of system foundations that are thought to be financially savvy, pragmatic and moderately adaptable framework setup for whole deal transport remote signs. This venture proposes a Next era PON construction modeling backings RoF and OFDMA signal coordination without WDM lasers, and exhibit that 10-Gb/s OFDMA and three RF signals at 2.1GHz are transmitted more than 20km SMF in a 32-ONU in both upstream and downstream bearing. A security control unit and an optical switch are utilized associating four Optical Line Terminations (OLTs) with everyone serving just 32 Optical Network Units (ONUs). Insurance control unit gathers data of ONUs served by each OLT, and when an OLT falls flat, it will educate an active OLT to help its unique ONUs together with the burden served by the fizzled OLT.

APA, Harvard, Vancouver, ISO, and other styles

17

Nashiruddin, Muhammad Imam, and Nomarhinta Solihah. "Development of Testing Standardization Regulation of the OLT XG-PON Equipments to Support Broadband Access in Indonesia." Journal Pekommas 5, no. 1 (April 24, 2020): 1. http://dx.doi.org/10.30818/jpkm.2020.2050101.

Full text

Abstract:

This study aims to provide a reference to the technical specifications of the Optical Line Termination (OLT) XG-PON equipment for improving standardization regulations (Perdirjen Postel No. 257 of 2008). The technical specifications tested in this study are the nominal rate capability, wavelength range, and jumbo frame of the OLT XG-PON equipment. The research acquired a reference to the nominal rate using FEC is 8.5 Gbps downstream direction, and 2.5 Gbps upstream direction, upstream wavelength range is 1260-1280 nm and downstream is 1575-1581 nm, and jumbo frame capability is 2000 Bytes.

APA, Harvard, Vancouver, ISO, and other styles

18

Ma, Jonathan, and Stephen Israel. "Virtualized Networks and Virtualized Optical Line Terminal (vOLT)." Fiber and Integrated Optics 36, no. 1-2 (February 10, 2017): 68–77. http://dx.doi.org/10.1080/01468030.2017.1283455.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Satriadi, Mathias Radi, and Rully Pramudita. "Implementasi Pembangunan Jaringan Mini Optical Line Termination di Kawasan Babelan milik PT Telekomunikasi Indonesia." INFORMATION MANAGEMENT FOR EDUCATORS AND PROFESSIONALS : Journal of Information Management 5, no. 2 (June 30, 2021): 63. http://dx.doi.org/10.51211/imbi.v5i2.1554.

Full text

Abstract:

Abstrak: Penelitian dengan judul pembangunan mini optical line termination di Kawasan Babelan, tujuan penelitian ini untuk mempelajari infrastruktur terbaru milik PT Telekomunikasi Indonesia yang mengembangkan jaringanya terus menerus untuk menjangkau wilayah yang belum mendapatkan akses internet, proses pembangunan jaringan fiber optik, PT Telekomunikasi Indonesia (Telkom) sebagai Badan Usaha Milik Negara (BUMN) yang berkonsenterasi pada bidang komunikasi, berhasil meluncurkan produk Internet Home (INDIHOME) sebagai Brand Image-nya guna memenuhi kebutuhan informasi komunikasi demi kemajuan bangsa Indonesia. Metode pengumpulan data meliputi studi lapangan dan studi pustaka. Studi lapangan meliputi praktek , wawancara dan pengamatan. Studi pustaka dilakukan dengan penilitian kepustakaan yang relevan dengan masalah yang dihadapi. Dari analisa dan pengamatan yang dilakukan bahwa jaringan akses fiber optik merupakan salah satu peningkatan yang baik guna meningkatkan efisiensi yang berpengaruh pada kecepatan mengirimkan paket data (internet). Kata kunci: Fiber Optik, Jaringan, Indihome, Optical Line Termination (OLT) Abstract: The research entitled the construction of a mini optical line termination in the Babelan area, the purpose of this research is to study the latest infrastructure owned by PT Telekomunikasi Indonesia which is developing its network continuously to reach areas that do not yet have internet access, the process of building a fiber optic network, PT Telekomunikasi Indonesia (Telkom) as The State-Owned Enterprises (BUMN), which concentrate on the communication sector, have successfully launched the Internet Home (INDIHOME) product as its Brand Image to meet the needs of communication information for the progress of the Indonesian nation. Data collection methods include field studies and literature studies. Field studies include practice, interviews and observations. Literature study is carried out with literature research that is relevant to the problem at hand. From the analysis and observations made that the fiber optic access network is one of the best improvements to improve efficiency which affects the speed of sending data packets (internet). Keywords: Fiber Optic, Network, Indihome, Optical Line Termination (OLT)

APA, Harvard, Vancouver, ISO, and other styles

20

Solihah, Nomarhinta, and Muhammad Imam Nashiruddin. "DEVELOPMENT OF MULTICAST SERVICE TECHNICAL REQUIREMENTS REGULATION ON XG-PON OLT EQUIPMENT." Jurnal Penelitian Pos dan Informatika 10, no. 1 (October 1, 2020): 59. http://dx.doi.org/10.17933/jppi.2020.100105.

Full text

Abstract:

Today the deployment of Fiber-To-The-x (FTTx) technology is developing very rapidly in various regions of Indonesia. One of the most favorite technologies for telecommunication operators is the XG-PON, which offers high-speed internet access speeds of 10Gbps downstream and 2.5Gbps upstream directions and able to pass various services at once, such as data, voice, to video multicast (IPTV) services. However, regulation of the standardization of technical requirements for multicast services does not include this new technology, so a reference test is needed to update the regulations. In this study, testing of Optical Line Termination (OLT) devices uses five scenarios, namely the ability to pass IGMP version 2, IGMP version 3, ability to support IGMP Snooping and IGMP proxy and capacity in passing several IGMP multicast groups. The test results show that the tested OLT XGPON device can display the suitability of the IGMP message format version 2 with the RFC 2236 standard and IGMP version 3 with the RFC 3376 Standard. Whereas in IGMP proxy testing traffic, the OLT equipment displays the source IP address is 0.0.0.0, which complies with the RFC 4541 standard for the Reporting proxy process. The OLT XG-PON device tested was also capable of passing 1,024 IGMP multicast groups with a range of multicast group addresses from 239.1.1.1 to 239.1.5.1.

APA, Harvard, Vancouver, ISO, and other styles

21

Kumar, Love, Amarpal Singh, and Vishal Sharma. "Analysis on multiple optical line terminal passive optical network based open access network." Frontiers of Optoelectronics 12, no. 2 (October 24, 2018): 208–14. http://dx.doi.org/10.1007/s12200-018-0767-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Rahmatia, Suci, and Rifqi Muhammad Imaduddin. "Perbandingan Karakteristik MSAN dan OLT Pada Implementasi Modernisasi Jaringan di Daerah Darmo, Surabaya." JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI 4, no. 4 (December 13, 2018): 182. http://dx.doi.org/10.36722/sst.v4i4.308.

Full text

Abstract:

Abstrak- Faktor pendorong pengembangan layanan telekomunikasi adalah terciptanya beberapa teknologi akses yang dapat mengoptimalkan akses layanan broadband. Teknologi ini berperan penting dalam mendukung hadirnya suatu layanan telekomunikasi dikenal dengan nama triple play. Layanan tersebut menggabungkan data, suara dan video (IPTV) dalam satu layanan. Layanan ini dapat dinikmati apabila jaringan akses lokal suatu wilayah sudah dimodernisasi dari Jarlokat (Jaringan Lokal Akses Tembaga) menjadi Jarlokaf (Jaringan Lokal Akses Fiber). Dalam pengaplikasiannya dilapangan, teknologi modernisasi ditentukan dengan berbagai faktor yaitu faktor demografi, geografi serta ekonomi. Kawasan Darmo, Surabaya merupakan daerah metropolitan residensial dengan kepadatan penduduk yang cukup tinggi, kondisi geografis sudah terbangun struktur backbone, dan kondisi ekonomi penduduknya menengah ke atas. Proses modernisasi jaringan di kawasan Darmo, Surabaya dapat diterapkan sistem full fiber/teknologi Optical Line Transmission (OLT) secara langsung tanpa melalui teknologi Multi Service Access Node (MSAN).Abstract - The driving factor for the development of telecommunications services is the creation of several access technologies that can optimize access to broadband services. This technology plays an important role in supporting the presence of a telecommunications service known as triple play. The service combines data, voice and video (IPTV) in one service. This service can be enjoyed if the local access network of a region has been modernized from Jarlokat (Local Access Copper Network) to Jarlokaf (Fiber Access Local Network). In its application, modernization technology is determined by various factors, namely demographic factors, geographical factors and economic factors. Darmo area, Surabaya is a residential metropolitan area with a high population density, geographical conditions that have been built optical backbone structure, and the economic conditions of the population are quite rich. The network modernization process in the Darmo area, Surabaya can be implemented full fiber system / Optical Line Transmission (OLT) technology directly without going through Multi Service Access Node (MSAN) technology.Keywords – Local Copper Access Network, Local Fiber Access Network, Triple Play, MSAN, OLT

APA, Harvard, Vancouver, ISO, and other styles

23

Eldaly, Zeiad, Wael Soliman, Mohamed Sharaf, and Ali Natag Reyad. "Morphological Characteristics of Normal Foveal Avascular Zone by Optical Coherence Tomography Angiography." Journal of Ophthalmology 2020 (August 19, 2020): 1–6. http://dx.doi.org/10.1155/2020/8281459.

Full text

Abstract:

Purpose. To provide quantitative measurements for the foveal avascular zone (FAZ) and to describe its morphological characteristics by optical coherence tomography angiography (OCT-A). Design. Cross-sectional observational case series. Methods. Healthy volunteers were recruited and evaluated using Triton-DRI SS-OCT Angiography. A 4.5 × 4.5 mm square was evaluated by OCT-A center around the fovea. Superficial and deep capillary plexus were identified, and different quantitative measurements were conducted along with categorization of the FAZ pattern. Results. Eighty-two eyes (41 volunteers) were evaluated. Mean age was 30.59 ± 7.6 years (23–42 years). Mean subcentral retinal thickness was 200.1 ± 5.66 um (192–210 um). The number of terminal vessels was variable (range, 8–11). Mean maximum terminal vessel-to-vessel intervening distance was 527.8 ± 60.3 um (471–674 um). Mean minimum terminal vessel-to-vessel intervening distance was 296.7 ± 45.8 um (233–373 um). Mean maximum horizontal diameter of FAZ (superficial) was 716.17 ± 124.09 um, while mean maximum vertical diameter of FAZ (superficial) was 667.76 ± 131.28 um. Mean maximum horizontal diameter of FAZ (deep) was 823.19 ± 144.92 um, while mean maximum vertical diameter of FAZ (deep) was 794.03 ± 150.28 um. OCT-A detected different FAZ patterns; horizontally oval configuration in 32 eyes (39%), rounded configuration in 24 eyes (29.3%), pentagon configuration in 14 eyes (17.1%), and vertically oval and nonspecific configuration in 6 eyes each (7.3%). Conclusion. OCT-A could efficiently provide both quantitative and qualitative assessment of normal FAZ; such characterizations were difficult by standard FAZ assessment procedures like FFA.

APA, Harvard, Vancouver, ISO, and other styles

24

Yoshikai, N., S. Nishi, and J. Yamada. "Line Code and Terminal Configuration for Very Large-Capacity Optical Transmission System." IEEE Journal on Selected Areas in Communications 4, no. 9 (December 1986): 1432–37. http://dx.doi.org/10.1109/jsac.1986.1146497.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Liu, Gao, Li Hui Wu, Bao Qiang Liu, Hu Zhang, Jin Bei Zheng, and Hong Shen. "Optical Fiber Sensor Salt Dense On-Line Monitoring Research." Applied Mechanics and Materials 325-326 (June 2013): 708–11. http://dx.doi.org/10.4028/www.scientific.net/amm.325-326.708.

Full text

Abstract:

To detect the pollution level of insulators in operation, based on light energy loss theory of medium optical wave guide and mathematical modeling of least squares supporting vector machine, by a lot of contrast tests, this paper designed and developed monitoring terminal of optical sensor. Collecting live temperature, humidity luminous flux attenuation etc. and sending the collected data to data monitoring centre through GSM data communication module, the workstation of data monitoring centre could calculate to get equivalent salt deposit density (ESDD) using mathematical model, so that insulators pollution level can be detected on-line automatically and continuously.

APA, Harvard, Vancouver, ISO, and other styles

26

Qin Panke, 秦攀科, 王立芊 Wang Liqian, 马骏 Ma Jun, 陈雪 Chen Xue, and 王磊 Wang Lei. "Dynamic Traffic Balancing Strategy Experiment on Optical Line Terminal of 40 G Coherent Passive Optical Network." Chinese Journal of Lasers 42, no. 4 (2015): 0405007. http://dx.doi.org/10.3788/cjl201542.0405007.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Isaji, Yoshihiro, Takehiro Sato, Hidetoshi Takeshita, Satoru Okamoto, and Naoaki Yamanaka. "Time estimation of logical optical line terminal migration for Elastic Lambda Aggregation Network." IEICE Communications Express 5, no. 3 (2016): 79–84. http://dx.doi.org/10.1587/comex.2015xbl0179.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Sato, Takehiro, Kunitaka Ashizawa, Hidetoshi Takeshita, Satoru Okamoto, Naoaki Yamanaka, and Eiji Oki. "Logical Optical Line Terminal Placement Optimization in the Elastic Lambda Aggregation Network With Optical Distribution Network Constraints." Journal of Optical Communications and Networking 7, no. 9 (August 28, 2015): 928. http://dx.doi.org/10.1364/jocn.7.000928.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Horvath, Tomas, Petr Munster, and Ning-Hai Bao. "Lasers in Passive Optical Networks and the Activation Process of an End Unit: A Tutorial." Electronics 9, no. 7 (July 9, 2020): 1114. http://dx.doi.org/10.3390/electronics9071114.

Full text

Abstract:

It is 21 years since the first passive optical network (PON) was standardized as an asynchronous transfer mode passive optical network (APON) with same optical distribution network scheme as we know in current networks. A lot of PON networks were standardized in the following years and became an important part of telecommunication. The general principles of these PON networks are described in many papers and books, but only a little information about used lasers is available. The aim of this tutorial is to describe lasers used in PON networks and principles of their operation. The paper describes the principles of single longitudinal mode (SLM), multi longitudinal mode (MLM), distributed-feedback (DFB), and Fabry–Pérot (FP) lasers. Furthermore, the lasers are compared by their usage in optical line termination (OLT) for passive optical networks. The second part of this tutorial deals with activation process of optical network unit. The described principle is the same for connection of a new customer or blackout scenario. The end unit is not able to communicate until reach the operational state; each state is defined with physical layer operation and administration and maintenance (PLOAM) messages sequence and their processing.

APA, Harvard, Vancouver, ISO, and other styles

30

Hu, Xiaofeng, Liang Zhang, Pan Cao, Kongtao Wang, and Yikai Su. "Energy-efficient WDM-OFDM-PON employing shared OFDM modulation modules in optical line terminal." Optics Express 20, no. 7 (March 22, 2012): 8071. http://dx.doi.org/10.1364/oe.20.008071.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Clupek, Vlastimil, Tomas Horvath, Petr Munster, and Vaclav Oujezsky. "New Security Improvements in Next-Generation Passive Optical Networks Stage 2." Applied Sciences 9, no. 20 (October 18, 2019): 4430. http://dx.doi.org/10.3390/app9204430.

Full text

Abstract:

Passive optical networks are currently the most promising solution for access networks. These networks rely on broadcast signal distribution in the downstream direction and unicast signal transmission in the upstream direction. The upstream direction is controlled by optical line termination (OLT). The broadcast transmission method increases security vulnerability because the attacker is able to connect his/her modified optical network unit (ONU) to the free port of the splitter (commonly in the basement). We present the concept for the activation process of ONUs based on physical unclonable function (PUF) for next-generation passive optical networks stage 2 (NG-PON2). The use of PUF increases security in the NG-PON2. Furthermore, the registration identifier (ID) is not stored in a nonvolatile memory, in comparison with the common solution defined by the International Telecommunication Union (ITU) recommendation G.989.3. An attacker cannot perform a reverse engineering attack to obtain the registration ID. For this reason, the attacker cannot clone an ONU. We proposed security improvements that involve authentication, encryption, integrity protection, and data origin verification methods in the NG-PON2. Our model uses the standard implementation of the transmission convergence layer of NG-PON2 with the new physical layer operations, administration, and maintenance (PLOAM) messages. The recommendation G.989.3 allows specifying own PLOAM messages since not all IDs are used in the current specification.

APA, Harvard, Vancouver, ISO, and other styles

32

Yin, Shu Hua. "Key Technologies of On-Line Monitoring Based on Optical Transport Networks." Applied Mechanics and Materials 556-562 (May 2014): 2681–84. http://dx.doi.org/10.4028/www.scientific.net/amm.556-562.2681.

Full text

Abstract:

To meet the comprehensive maintenance demand of optical fiber transportation networks, an integrated optical cable on-line monitoring system is designed in this research. The researched employs modular structure, integrated function, and blended multiple communication interfaces for the key technologies of monitoring 128 modules. By using the technologies, speech path and signaling are able to transmit simultaneously. Then the research establishes the on-line monitoring system which integrates the functions of real-time monitoring of terminal offices on optical cable line and end machine, automatic dispatching of circuits, and maintenance test for optical transportation equipment. By applying the system on-line, the research verifies that the functions and technical indexes of the system meet its design requirements.

APA, Harvard, Vancouver, ISO, and other styles

33

Kataoka, T., M. Tomizawa, T. Ono, A. Matsuura, S. Kuwahara, Y. Kisaka, Y. Miyamoto, et al. "Design of a 43-Gb/s line terminal based on optical transport network system architecture." Journal of Lightwave Technology 20, no. 12 (December 2002): 2057–66. http://dx.doi.org/10.1109/jlt.2002.806759.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Dong, Z., J. Lu, Z. Cao, and L. Chen. "Low-cost optical line terminal for a WDM-PON compatible with radio-over-fiber systems." Journal of Optical Networking 8, no. 3 (February 11, 2009): 244. http://dx.doi.org/10.1364/jon.8.000244.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Oh, Su Hwan, Jang-Uk Shin, Ki Soo Kim, Dong-Hoon Lee, Sang-Ho Park, Hee-Kyung Sung, Yong-Soon Baek, and Kwang-Ryong Oh. "200 GHz-spacing 8-channel multi-wavelength lasers for WDM-PON optical line terminal sources." Optics Express 17, no. 11 (May 21, 2009): 9401. http://dx.doi.org/10.1364/oe.17.009401.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Bai, Wei, Hui Yang, Hongyun Xiao, Ao Yu, Linkuan He, Jie Zhang, Zhen Li, and Yi Du. "De-optical-line-terminal hybrid access–aggregation optical network for time-sensitive services based on software-defined networking orchestration." Optical Engineering 56, no. 11 (November 15, 2017): 1. http://dx.doi.org/10.1117/1.oe.56.11.116111.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Yeh, Bih-Chyun. "Noncoherent spectral optical CDMA system using 1-D subtracted square codes of all transmitters in one optical line terminal." Photonic Network Communications 34, no. 1 (September 12, 2016): 75–83. http://dx.doi.org/10.1007/s11107-016-0661-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Ullah, Rahat, Liu Bo, Sibghat Ullah, Mao Yaya, Feng Tian, Muhammad Kamran Khan, and Xin Xiangjun. "Flattened Optical Multicarrier Generation Technique for Optical Line Terminal Side in Next Generation WDM-PON Supporting High Data Rate Transmission." IEEE Access 6 (2018): 6183–93. http://dx.doi.org/10.1109/access.2018.2789863.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Oh, Su Hwan, Jang-Uk Shin, Yoon-Jung Park, Sung-Bock Kim, Sahnggi Park, Hee-Kyung Sung, Yong-Soon Baek, and Kwang-Ryong Oh. "Multiwavelength Lasers for WDM-PON Optical Line Terminal Source by Silica Planar Lightwave Circuit Hybrid Integration." IEEE Photonics Technology Letters 19, no. 20 (October 2007): 1622–24. http://dx.doi.org/10.1109/lpt.2007.904922.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Ren, Hao, Qi Wei Du, Ren Hui Dou, and Zhi Qiang Yao. "The Research and Application on Design Method for “Virtual Terminal” of Smart Substation." Advanced Materials Research 1070-1072 (December 2014): 1418–22. http://dx.doi.org/10.4028/www.scientific.net/amr.1070-1072.1418.

Full text

Abstract:

According to the new changes brought out by the smart substation, including disappearance of the traditional concept of terminal and replacement of the original point to point cable connection by optical fiber network, a new design method of GOOSE “virtual terminal” is put forward. The method contains GOOSE “virtual terminal”, virtual terminal logic connection line, GOOSE configuration table and virtual terminal information flow diagram, and solves some problems of digital protection, measurement and control device, such as without contact, no terminal, no wiring etc. of GOOSE information. The design method was applied in the engineering practice of the south of Changshu 500kV smart substation in Suzhou, and the effect of designing was very good.

APA, Harvard, Vancouver, ISO, and other styles

41

Li, He, Hongxi Yin, and Shanshan Lin. "A novel optical network model for network burden release and congestion reduction based on passive optical network." International Journal of Distributed Sensor Networks 14, no. 10 (October 2018): 155014771880765. http://dx.doi.org/10.1177/1550147718807652.

Full text

Abstract:

In this article, a new optical network structure coping with network congestion is proposed, which is based on passive optical network, and adopts data storage devices coupled with optical line terminal to release network burden. It is shown by our network performance simulation that this network has many merits such as free-scale, fewer connections, larger clustering coefficient, and smaller average shortest path length in comparison to the passive optical network. The novel network structure can replace the far-end service connections with the near-end ones, reduce congestions in an optical network, and, furthermore, relieve traffic burden in optical backbone and metropolitan area networks.

APA, Harvard, Vancouver, ISO, and other styles

42

Li, Xiangchao, Lei Chu, Hua Luo, Qiaoli Wen, and Wen Ouyang. "Analysis of coupling characteristics of coaxial line parallel to lightning current channel." International Journal of Applied Electromagnetics and Mechanics 66, no. 2 (June 11, 2021): 205–23. http://dx.doi.org/10.3233/jae-190153.

Full text

Abstract:

Base on the analysis of the coaxial coupling theory, the experimental model of the coaxial cable short-range coupling lightning electromagnetic pulse is established to study the problem of coaxial cable short-range coupling lightning electromagnetic pulse on the ship mast and high tower. The combination wave generator is used to simulate the 8/20 μs lightning current waveform, and the metal bar with the length of 1 m and diameter of 0.016 m is used to simulate the lightning channel as the radiation source. The length of the coaxial cable and the distance from the radiation source are changed for the test. The conclusion is as follows: when the coaxial cable is coupled with lightning wave in a short distance, the voltage waveform of cable terminal is still double exponential wave, with strong damping oscillation at 0.1 ∼0.4 μs. When the cable terminal is open circuit or connected with matching resistance, the rising time is shorter, about 1 μs; when the cable terminal shielding layer is grounded, the rising time is longer, about 10 μs. The peak voltage and energy coupled to the coaxial cable at short distance are positively correlated with the cable length, and inversely correlated with the distance from the radiation source. The energy that the cable is coupled to mainly comes from the low-frequency part, and there are multiple energy peaks below 100 Hz. Using fitting curve and experimental data, when the coaxial cable terminal is open circuit, the lightning current reaches 30 kA, the cable length is 30 m, and the distance from the lightning channel is 0.15 m, the peak value of the voltage coupled to the cable terminal is 66 V. It has certain guiding significance and value in the practical application of electromagnetic pulse protection.

APA, Harvard, Vancouver, ISO, and other styles

43

Hu, Xiaofeng, Pan Cao, Zhiming Zhuang, Liang Zhang, Qi Yang, and Yikai Su. "Energy-efficient optical line terminal for WDM-OFDM-PON based on two-dimensional subcarrier and layer allocation." Optics Express 20, no. 23 (October 22, 2012): 25284. http://dx.doi.org/10.1364/oe.20.025284.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Gormaz-Matamala, Alex C., Michel Curé, Lydia Cidale, and Roberto Venero. "New Solutions to Line-Driven Winds of Hot Massive Stars." Proceedings of the International Astronomical Union 12, S329 (November 2016): 401. http://dx.doi.org/10.1017/s1743921317002101.

Full text

Abstract:

AbstractIn the frame of radiation driven wind theory (Castor et al.1975), we present self-consistent hydrodynamical solutions to the line-force parameters (k, α, δ) under LTE conditions. Hydrodynamic models are provided by HydWind (Curé 2004). We evaluate these results with those ones previously found in literature, focusing in different regions of the optical depth to be used to perform the calculations. The values for mass-loss rate and terminal velocity obtained from our calculations are also presented.We also examine the line-force parameters for the case when large changes in ionization throughout the wind occurs (δ-slow solutions, Curé et al.2011).

APA, Harvard, Vancouver, ISO, and other styles

45

Yeh, Bih-Chyun, Cheing-Hong Lin, and De-Nian Yang. "Universal optical line terminal encoding and decoding architecture in two-code keying for noncoherent spectral amplitude coding optical code division multiple access systems." Optical Engineering 53, no. 1 (January 6, 2014): 016104. http://dx.doi.org/10.1117/1.oe.53.1.016104.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Fu, Meixia, Min Zhang, Danshi Wang, Yue Cui, and Huanhuan Han. "10-Gbps optical duobinary signal generated by bandwidth-limited reflective semiconductor optical amplifier in colorless optical network units and compensated by fiber Bragg grating-based equalizer in optical line terminal." Optical Engineering 55, no. 10 (October 6, 2016): 106102. http://dx.doi.org/10.1117/1.oe.55.10.106102.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Weber, Marko, Jessica Rüddel, Tony Bruns, Mathias Pletz, and Andreas Stallmach. "Pulmonary co-infection with nocardia species and nontuberculous mycobacteria mimicking miliary tuberculosis in a patient with Crohn’s disease under combined immunosuppressive therapy." Zeitschrift für Gastroenterologie 56, no. 06 (June 2018): 569–72. http://dx.doi.org/10.1055/a-0614-2871.

Full text

Abstract:

AbstractNocardiosis is a rare infection caused by ubiquitous soil-born, acid-resistant, Gram-positive bacteria that can be life-threatening in immunocompromised patients. Originally usually diagnosed in HIV-positive patients, only few cases have been reported in patients on immunosuppressive therapy for inflammatory bowel disease or rheumatologic disorders. We present a case of a 32-year-old man who was treated with infliximab, prednisolone, and azathioprine for severe terminal ileitis. Although the clinical status improved under triple immunosuppressive therapy, weight loss, weakness, and fatigue persisted. Laboratory studies revealed iron deficiency anemia, hypalbuminemia and raised inflammatory markers. Chest computed tomography scan showed multiple pulmonary nodules and a large cavity in the left upper lobe (segment 3a). Empiric tuberculostatic therapy was introduced for suspected miliary tuberculosis but stopped for lack of clinical improvement and negative tuberculosis tests (interferon-gamma release assay, microscopy, polymerase chain reaction). Finally, the diagnosis of pulmonary nocardiosis with concomitant pulmonary Mycobacterium avium infection was confirmed microbiologically, and the patient was treated with high-dose co-trimoxazole, clarithromycin, ethambutol, and rifampicin for 12 months.This case report underlines the increased risk of severe and rare infections like nocardiosis with combination immunosuppressive therapy and the necessity for thorough diagnostic screening for opportunistic infection. Although long-term antibiotic treatment for nocardiosis is mandatory, the optimal timing to restart immunosuppressive therapy remains ambiguous.

APA, Harvard, Vancouver, ISO, and other styles

48

Siddiqui, Aleem M., Lisa P. Hackett, Daniel Dominguez, Anna Tauke-Pedretti, Tom Friedmann, Gregory Peake, Michael R. Miller, James K. Douglas, and Matt Eichenfield. "Comparison of amplification via the acousto-electric effect of Rayleigh and Leaky-SAW modes in a monolithic surface InP:InGaAs/lithium niobate heterostructure." Ferroelectrics 557, no. 1 (March 11, 2020): 58–65. http://dx.doi.org/10.1080/00150193.2020.1713363.

Full text

Abstract:

This paper demonstrates a monolithic surface acoustic wave amplifier fabricated by state-of-the-art heterogenous integration of a III-V InGaAs-based epitaxial material stack and LiNbO3. We compare amplification of Raleigh-SAW and leaky-SAW modes on a on Y-cut, X-propagating delay line amplifier. Due to the superior properties of the materials employed, we observe a net terminal gain of 3dB for an LSAW overtone mode This platform enables further advances in active and non-reciprocal piezoelectric acoustic devices.

APA, Harvard, Vancouver, ISO, and other styles

49

Gao, Ya, and Xia Gao. "An Optical Distribution Network Partitioning Method Based on the Branch-and-Bound." Applied Mechanics and Materials 427-429 (September 2013): 2399–402. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.2399.

Full text

Abstract:

Optical Distribution Network is a kind of optical transmission path connecting Optical Line Terminal and Optical Network Unit. This article mainly studies how to optimize broadband loan problems of the backbone network. In order to get the best allocation scheme of the Optical Distribution Network problems, we propose a solution which is converting the Optical Distribution Network partitioning problem into a graph partitioning model, and solve the problem by adopting Graph partitioning algorithms. Graph partitioning is about the undirected graph , is the collection of all vertexes. is the collection of all sides. Any vertex in the vertex set has weight value of a positive integer. Any side in a side set has weight value of a positive integer. The vertex set is divided into non-intersecting subsets , and .As to every subset , it has ,,.What we need to solve is to get the minimum sum of weight values between m non-intersecting subsets. The experimental results show that Graph partitioning algorithm is efficient.

APA, Harvard, Vancouver, ISO, and other styles

50

Marbel, Revital, Boaz Ben-Moshe, and Tal Grinshpoun. "Urban Free-Space Optical Network Optimization." Applied Sciences 10, no. 21 (November 6, 2020): 7872. http://dx.doi.org/10.3390/app10217872.

Full text

Abstract:

This paper presents a set of graph optimization problems related to free-space optical communication networks. Such laser-based wireless networks require a line of sight to enable communication, thus a visibility graph model is used herein. The main objective is to provide connectivity from a communication source point to terminal points through the use of some subset of available intermediate points. To this end, we define a handful of problems that differ mainly in the costs applied to the nodes and/or edges of the graph. These problems should be optimized with respect to cost and performance. The problems at hand are shown to be NP-hard. A generic heuristic based on a genetic algorithm is proposed, followed by a set of simulation experiments that demonstrate the performance of the suggested heuristic method on real-life scenarios. The suggested genetic algorithm is compared with the Euclidean Steiner tree method. Our simulations show that in many settings, especially in dense graphs, the genetic algorithm finds lower-cost solutions than its competitor, while it falls behind in some settings. However, the run-time performance of the genetic algorithm is considerably better in graphs with 1000 nodes or more, being more than twice faster in some settings. We conclude that the suggested heuristic improves run-time performance on large-scale graphs and can handle a wider range of related optimization problems. The simulation results suggest that the 5G urban backbone may benefit significantly from using free-space optical networks.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Optical Line Terminal (OLT)'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles