Refining the GIANT dynamic bandwidth allocation mechanism for XG-PON

XG-PON requires an effective dynamic bandwidth allocation (DBA) mechanism for upstream traffic to support quality of service for different classes of traffic. We propose X-GIANT, which extends GPON based GigaPON Access Network (GIANT) DBA, with validated optimisations to the originally proposed key parameters - service timers and assured vs non-assured ratio of medium priority traffic. We implement X-GIANT in a standard compliant XG-PON module designed for the state-of-the-art ns-3 simulator, tune the above key parameters and show that mean delay and throughput for different classes of traffic obey the XG-PON requirements and respect priorities at both light and heavy upstream loads. We also show that X-GIANT shows better mean-delay performance than Efficient Bandwidth Utilisation (EBU), a recently proposed, GIANT-derived, priority-based DBA mechanism for XG-PON, for all three classes of traffic simulated

Modified GIANT Dynamic Bandwidth Allocation Algorithm of NG-PON

Gigabit passive optical networks have been widely deployed due to the fact that the cost of their implementation is still decreasing. What is more important, we are facing theproblem with increasing demands on the transmission bandwidth. Regarding this issue, the ITU develops another two standards supporting higher downstream bitrate. The XG-PON standard is the first platform under the developing, and the NG-PON2 is the second standard. The first one provides compatibility and increases the downstream capacity of 10 Gbit/s and the second standard has the same assumptions, but does not have backward compatibility. In this article, we discuss only XG-PON networks. We choose amendment as the dynamic bandwidth allocation algorithms, and we have compared it with the original specification and with our modification. The primary intention of that modification is to reduce the delay of Triple Play (data, video, and voice) services. These services are represented by TCONT (Transmission Container), which is used to improve the PON system upstream bandwidth allocation and transmission status dynamically. As NS-3 simulator does not support the direct mapping of Triple Play services into T-CONT and their labeling. We focus on a delay value for Triple Play services which was reduced by own modification in a GIANT algorithm. On the other hand, we cannot reduce the delay value for VoIP services because it has the highest priority by T-CONT

A Quality of Service framework for upstream traffic in LTE across an XG-PON backhaul

Passive Optical Networks (PON) are promising as a transport network technology due to the high network capacity, long reach and strong QoS support in the latest PON standards. Long Term Evolution (LTE) is a popular wireless technology for its large data rates in the last mile. The natural integration of LTE and XG-PON, which is one of the latest standards of PON, presents several challenges for XG-PON to satisfy the backhaul QoS requirements of aggregated upstream LTE applications. This thesis proves that a dedicated XG-PON-based backhaul is capable of ensuring the QoS treatment required by different upstream application types in LTE, by means of standard-compliant Dynamic Bandwidth Allocation (DBA) mechanisms. First the design and evaluation of a standard-compliant, robust and fast XG-PON simulation module developed for the state-of-the-art ns-3 network simulator is presented in the thesis. This XG-PON simulation module forms a trustworthy and large-scale simulation platform for the evaluations in the rest of the thesis, and has been released for use by the scientific community. The design and implementation details of the XGIANT DBA, which provides standard complaint QoS treatment in an isolated XG-PON network, are then presented in the thesis along with comparative evaluations with the recently-published EBU DBA. The evaluations explored the ability of both XGIANT and EBU in terms of queuing-delay and throughput assurances for different classes of simplified (deterministic) traffic models, for a range of upstream loading in XG-PON. The evaluation of XGIANT and EBU DBAs are then presented for the context of a dedicated XG-PON backhaul in LTE with regard to the influence of standard-compliant and QoS-aware DBAs on the performance of large-scale, UDP-based applications. These evaluations disqualify both XGIANT and EBU DBAs in providing prioritised queuing delay performances for three upstream application types (conversational voice, peer-to-peer video and best-effort Internet) in LTE; the evaluations also indicate the need to have more dynamic and efficient QoS policies, along with an improved fairness policy in a DBA used in the dedicated XG-PON backhaul to ensure the QoS requirements of the upstream LTE applications in the backhaul. Finally, the design and implementation details of two standard-compliant DBAs, namely Deficit XGIANT (XGIANT-D) and Proportional XGIANT (XGIANT-P), which provide the required QoS treatment in the dedicated XG-PON backhaul for all three application types in the LTE upstream are presented in the thesis. Evaluations of the XGIANT-D and XGIANT-P DBAs presented in the thesis prove the ability of the fine-tuned QoS and fairness policies in the DBAs in ensuring prioritised and fair queuing-delay and throughput efficiency for UDP- and TCP-based applications, generated and aggregated based on realistic conditions in the LTE upstream

Optimised QoS-aware DBA mechanisms in XG-PON for upstream traffic in LTE backhaul

Passive Optical Networks (PON) are viewed as an attractive choice to provide flexible and cost-efficient backhaul for Long Term Evolution (LTE) cellular base stations (eNB). PONs, such as the 10-Gigabit capable PON (XG-PON), use a Dynamic Bandwidth Allocation (DBA) mechanism to multiplex the shared upstream medium between competing sending nodes. Due to the complex definitions of QoS for DBA in XG-PON, it is a challenge for the XG-PON to respect the Quality of Service (QoS) requirements for different aggregated upstream applications in the LTE backhaul, in particular voice, live video and best-effort Internet traffic. In this paper, we first evaluate two recent XG-PON-standard-compliant DBAs - XGIANT and Efficient Bandwidth Utilisation (EBU) - for mean queuing-delay performance, with regard to priority and fairness, when the realistically-generated upstream voice, video and best-effort applications are aggregated at the evolved Node B (eNB) in LTE. We show that neither XGIANT nor EBU satisfy the priority and fairness requirements for mean queuing-delay. We propose and evaluate two optimised DBAs - Deficit XGIANT (XGIANT-D) and Proportional XGIANT (XGIANT-P). Our evaluations of the optimised DBAs, in the ns-3 network simulator, show that both XGIANT-D and XGIANT-P are able to ensure strictly prioritised, low and fair mean-queuing-delays for eNB-aggregated voice, video and best-effort traffic in two loaded conditions in XG-PON upstream. XGIANT-D and XGIANT-P, when compared with XGIANT and EBU, also ensure lower packet losses for eNB-aggregated upstream traffic in the XG-PON-based LTE backhaul

Configuración de servicios en entornos GPON

[ES] En respuesta a la creciente demanda de redes más rápidas, eficientes y fiables han surgido las redes ópticas pasivas (PON) que en los últimos años se han extendido por todos los proveedores de servicios, como método principal en la red de acceso, ya que garantiza un bajo coste, alta escalabilidad y compatibilidad a futuro. Debido a esto, en este documento se realiza el montaje y configuración de la infraestructura de una red GPON real, usando los equipos del fabricante TELNET. además, se desarrolla una cabecera que pueda ofrecer servicios Triple Play (Video, VoIP y acceso a Internet con QoS). Para configurar los equipos se usara la línea de comandos que ofrece mayor flexibilidad y opciones de configuración, permitiendo así analizar el impacto que tienen las diferentes alternativas de los comandos sobre la calidad de servicio. Se implementa el núcleo de la red con: Open vSwitch y los servicios típicos en este tipo de redes, sobre un entorno virtualizado donde finalmente se analiza el estado de los canales por medio de sflow. Finalmente al evaluar la infraestructura de red configurada, se puede apreciar como la utilización del canal esta siendo utilizada al máximo, lo cual permite obtener el máximo beneficio de la red, y mantener la calidad de los servicios sensibles IPTV y VOIP.Orozco Santos, F. (2019). Configuración de servicios en entornos GPON. http://hdl.handle.net/10251/13382

Refining the GIANT dynamic bandwidth allocation mechanism for XG-PON

XG-PON requires an effective dynamic bandwidth allocation (DBA) mechanism for upstream traffic to support quality of service for different classes of traffic. We propose X-GIANT, which extends GPON based GigaPON Access Network (GIANT) DBA, with validated optimisations to the originally proposed key parameters - service timers and assured vs non-assured ratio of medium priority traffic. We implement X-GIANT in a standard compliant XG-PON module designed for the state-of-the-art ns-3 simulator, tune the above key parameters and show that mean delay and throughput for different classes of traffic obey the XG-PON requirements and respect priorities at both light and heavy upstream loads. We also show that X-GIANT shows better mean-delay performance than Efficient Bandwidth Utilisation (EBU), a recently proposed, GIANT-derived, priority-based DBA mechanism for XG-PON, for all three classes of traffic simulated

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

The Fifteenth Marcel Grossmann Meeting

The three volumes of the proceedings of MG15 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 40 morning plenary talks over 6 days, 5 evening popular talks and nearly 100 parallel sessions on 71 topics spread over 4 afternoons. These proceedings are a representative sample of the very many oral and poster presentations made at the meeting.Part A contains plenary and review articles and the contributions from some parallel sessions, while Parts B and C consist of those from the remaining parallel sessions. The contents range from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theory, to precision tests of general relativity including progress towards the detection of gravitational waves, and from supernova cosmology to relativistic astrophysics, including topics such as gamma ray bursts, black hole physics both in our galaxy and in active galactic nuclei in other galaxies, and neutron star, pulsar and white dwarf astrophysics. Parallel sessions touch on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, white dwarfs, binary systems, radiative transfer, accretion disks, quasars, gamma ray bursts, supernovas, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, numerical relativity, gravitational lensing, large scale structure, observational cosmology, early universe models and cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, global structure, singularities, chaos, Einstein-Maxwell systems, wormholes, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors and data analysis, precision gravitational measurements, quantum gravity and loop quantum gravity, quantum cosmology, strings and branes, self-gravitating systems, gamma ray astronomy, cosmic rays and the history of general relativity

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 235)

This publication is a cummulative index to the abstracts contained in Supplements 223 through 234 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number