1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network ... more 1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network solutions have to be found. One candidate to meet the requirements (bandwidth, reach, energy efficiency, and total cost (CapEx and OpEx)) for next-generation access (NGA) is ...
ABSTRACT DP-DQDB (Quaternary Duobinary) and DP-DQPSK with Nyquist pulse shaping, both with cohere... more ABSTRACT DP-DQDB (Quaternary Duobinary) and DP-DQPSK with Nyquist pulse shaping, both with coherent reception, are compared w.r.t. the achievable spectral efficiency when employed as closely packed subcarriers of a superchannel without optical filtering of the subchannels.
Optical Fiber Communication Conference/National Fiber Optic Engineers Conference 2013, 2013
ABSTRACT WDM-based next-generation access systems have been compared to G-PON/XG-PON1 for high pe... more ABSTRACT WDM-based next-generation access systems have been compared to G-PON/XG-PON1 for high per-user bandwidths and access-node consolidation. Only with increasing sustained user bandwidth and decreasing node number, WDM-PON gets increasingly efficient.
Today, there is a major trend in broadband metro access networks towards FTTx (Fiber-To-The-x, wh... more Today, there is a major trend in broadband metro access networks towards FTTx (Fiber-To-The-x, where x stands for Home (H), Building (B), Curb, or Cabinet). FTTx can be based on active Point-to-Point/Ethernet, or Passive Optical Networks (PON). Many agree that PON-based FTTH/FTTB will win mid- to long-term over other deployment scenarios because of high bandwidths at comparatively low cost. However, there is also debate as to whether or not the future passive access network should be based on Time-Domain Multiple Access (TDMA, as known from GPON and EPON) or on WDM/WDMA (Wavelength-Domain Multiple Access). In this paper, we analyze requirements for the unified next-generation access and backhaul infrastructure. We conclude that this infrastructure should be based on WDM rather than TDMA in order to accommodate future band-width requirements whilst at the same time supporting backhaul and business access applications most efficiently.
This paper investigates Next-Generation Access for a given deployment scenario. Near-term hybrid ... more This paper investigates Next-Generation Access for a given deployment scenario. Near-term hybrid WDM/TDM solutions for long reach and high subscriber count at high bandwidth are considered. Capital expenditures, energy cost, and duct cost are derived, and the systems cost of different partly passive solutions is analyzed. Finally, requirements on feeder fibers are discussed.
WDM-PON based on low-cost tunable lasers is a promising candidate for next-generation broadband o... more WDM-PON based on low-cost tunable lasers is a promising candidate for next-generation broadband optical access. For cost reasons, the tunable lasers must not be equipped with dedicated coolers and wavelength lockers. Then, correct tuning of the lasers must be ensured by cost-effective tuning mechanisms which are implemented and shared in the system context. In this paper, we describe several approaches to WDM-PON and how wavelength locking can be implemented.
Today, there is a major trend in metro access networks towards FTTx (Fiber-To-The-x, where x stan... more Today, there is a major trend in metro access networks towards FTTx (Fiber-To-The-x, where x stands for Home (H), Building (B), Curb, or Cabinet). Many agree that FTTH/FTTB will win mid- to long-term over other deployment scenarios because of a higher available bandwidth. Future metro networks need to maximize cost efficiency. This leads to requirements of reducing general OpEx (Operational Expenditures) and the numbers of active (concentrator) sites in the network in particular. This requires the consolidation of the three main metro area applications onto one common metro access & backhauling platform. These applications are (wireless, wireline) backhaul, business/enterprise access, and high bandwidth residential access. Whilst these applications today use different technologies (e.g., active point-to-point Ethernet, CWDM rings, VDSL and/or GPON) for the first mile, they need a converged infrastructure for efficient backhaul. In some networks, GPON is already being deployed for no...
2010 12th International Conference on Transparent Optical Networks, 2010
Efforts towards commercializing higher-speed optical transmission have demonstrated the need for ... more Efforts towards commercializing higher-speed optical transmission have demonstrated the need for advanced modulation formats, several of which require similar transceiver hardware architecture. Adaptive transceivers can be built which have different operational configurations controlled by software. These software-defined transceiver configurations support a set of specific modulation / demodulation formats, with respective data rates and tolerances to system impairments, as well as
Erste numerische Analysen und Vergleiche von dreistufigen Duobinär-und PAM-4-kodierten Signalen f... more Erste numerische Analysen und Vergleiche von dreistufigen Duobinär-und PAM-4-kodierten Signalen für die Übertragung mit Bitraten von 28 Gb/s bzw. 40 Gb/s in PONs der nächsten Generation auf Standardeinmodenfaser im C-Band werden vorgestellt. Hierbei werden Sender/Empfänger mit 10 GHz, 20 GHz, 28 GHz und 40 GHz betrachtet und die grundlegende Nutzbarkeit von kosteneffizienten bandbegrenzten Komponenten gezeigt. Weiter zeigt das Duobinär-Verfahren bei kleineren Distanzen bessere Empfindlichkeit, während dies bei größeren Distanzen für PAM-4 der Fall ist. Die analysierten Komponentenkosten sind für beide Verfahren ähnlich.
Spectrum-efficient optical transmission with bitrates of 400 Gb/s and beyond can be achieved usin... more Spectrum-efficient optical transmission with bitrates of 400 Gb/s and beyond can be achieved using flexible modulation with advanced DSPs. The technology options include modulation format, signal baud rate, number of subcarriers, and spectral bandwidth. A fine-granular spectral bandwidth requires a flexible WDM grid as recently defined by ITU-T. Transmission of a signal with multiple optical carriers, each potentially with their own set of modulation options, allows bandwidth-variable multi-flow transceivers. This can reduce the spectrum continuity constraint in the network. At the network layer, these new degrees of freedom create additional levels of complexity and constraints during network design, planning and operation. Which modulation constellation should be chosen for a new optical connection? What are the impacts on transmission reach, spectrum continuity constraints, and network utilization? Routing and spectrum assignment is becoming more complex, and the inevitable spect...
Over the last three years, a comprehensive techno-economic analysis of Next-Generation Optical Ac... more Over the last three years, a comprehensive techno-economic analysis of Next-Generation Optical Access (NGOA) has been performed in the EU FP7 project OASE (Optical Access Seamless Evolution). Several types of Passive as well as Active Optical Networks (PON/AON) have been investigated, with regard to system, cabling and fiber cost, and Operational Expenditures (OpEx) including operations, maintenance, and energy-consumption cost. The analysis was performed for several degrees of active-site consolidation as well as for several sustainable per-client bit rates. Here, the analysis of the relevant PON approaches is presented with focus on system and infrastructure costs. With increasing site-consolidation degree and per-client bit rate, the optimum solution shifts from G-PON / XG-PON1 towards WDM-based PON solutions.
Optical Metro Networks and Short-Haul Systems II, 2010
Fueled by the steady traffic increase in access and enterprise networks, optical metro networks r... more Fueled by the steady traffic increase in access and enterprise networks, optical metro networks represent a major growth opportunity for system vendors and component manufacturers. This paper reviews new developments from a technical and economic point of view. Topics such as network and node architectures, high-speed transmission, integrated optical/electronic switching as well as management and control will be discussed.
Optical Fiber Communication Conference/National Fiber Optic Engineers Conference 2011, 2011
1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network ... more 1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network solutions have to be found. One candidate to meet the requirements (bandwidth, reach, energy efficiency, and total cost (CapEx and OpEx)) for next-generation access (NGA) is ...
37th European Conference and Exposition on Optical Communications, 2011
ABSTRACT This paper investigates insertion loss, maximum reach, client count, power consumption, ... more ABSTRACT This paper investigates insertion loss, maximum reach, client count, power consumption, and associated cost of WDM-based Next-Generation PON under consideration of real-world fiber attenuation and penalties for patches, splices and in-house cabling.
Optical Fiber Communication Conference and National Fiber Optic Engineers Conference, 2009
ABSTRACT TCO of access networks is determined by operational expenditures, with energy cost being... more ABSTRACT TCO of access networks is determined by operational expenditures, with energy cost being one of the major contributors. We show that WDM-PON, although not lowest in capital expenditures, is a future-proof solution which minimizes TCO.
ABSTRACT Latest results of the Optical Access Seamless Evolution project on next-generation optic... more ABSTRACT Latest results of the Optical Access Seamless Evolution project on next-generation optical access enabling node consolidation will be presented. Based on a technical and economical assessment different architecture options will be compared.
ABSTRACT The paper deals with the subject of how to build a core network in the current technolog... more ABSTRACT The paper deals with the subject of how to build a core network in the current technology scenario. We start with an overview ofwhat we consider a core network, not in an abstract way but referring to real country situations, and pointing out the differentaspects conditioning its realisation – population distribution, territory shape, traffic characteristics. In the next section asummary of different network topologies is presented and briefly analysed – rings, meshes, loosely or tightly interconnected,with particular attention to the resilience aspect in case of faults. The following section is dedicated to a short presentation of thecurrent technology scenario and how it reflects on the network elements (NEs) offered on the market (OXC, OADM, PXC, etc).Finally, the question is posed: “What is the best way to implement a core network?” with the conclusion being that there is nosingle answer – each situation must be pursued on a case-by-case basis.
ABSTRACT We report a network-wide comparison of WDM-based Next-Generation PON access solutions, b... more ABSTRACT We report a network-wide comparison of WDM-based Next-Generation PON access solutions, based on an infrastructure, power consumption and system cost analysis, of a real-world network deployment scenario.
1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network ... more 1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network solutions have to be found. One candidate to meet the requirements (bandwidth, reach, energy efficiency, and total cost (CapEx and OpEx)) for next-generation access (NGA) is ...
ABSTRACT DP-DQDB (Quaternary Duobinary) and DP-DQPSK with Nyquist pulse shaping, both with cohere... more ABSTRACT DP-DQDB (Quaternary Duobinary) and DP-DQPSK with Nyquist pulse shaping, both with coherent reception, are compared w.r.t. the achievable spectral efficiency when employed as closely packed subcarriers of a superchannel without optical filtering of the subchannels.
Optical Fiber Communication Conference/National Fiber Optic Engineers Conference 2013, 2013
ABSTRACT WDM-based next-generation access systems have been compared to G-PON/XG-PON1 for high pe... more ABSTRACT WDM-based next-generation access systems have been compared to G-PON/XG-PON1 for high per-user bandwidths and access-node consolidation. Only with increasing sustained user bandwidth and decreasing node number, WDM-PON gets increasingly efficient.
Today, there is a major trend in broadband metro access networks towards FTTx (Fiber-To-The-x, wh... more Today, there is a major trend in broadband metro access networks towards FTTx (Fiber-To-The-x, where x stands for Home (H), Building (B), Curb, or Cabinet). FTTx can be based on active Point-to-Point/Ethernet, or Passive Optical Networks (PON). Many agree that PON-based FTTH/FTTB will win mid- to long-term over other deployment scenarios because of high bandwidths at comparatively low cost. However, there is also debate as to whether or not the future passive access network should be based on Time-Domain Multiple Access (TDMA, as known from GPON and EPON) or on WDM/WDMA (Wavelength-Domain Multiple Access). In this paper, we analyze requirements for the unified next-generation access and backhaul infrastructure. We conclude that this infrastructure should be based on WDM rather than TDMA in order to accommodate future band-width requirements whilst at the same time supporting backhaul and business access applications most efficiently.
This paper investigates Next-Generation Access for a given deployment scenario. Near-term hybrid ... more This paper investigates Next-Generation Access for a given deployment scenario. Near-term hybrid WDM/TDM solutions for long reach and high subscriber count at high bandwidth are considered. Capital expenditures, energy cost, and duct cost are derived, and the systems cost of different partly passive solutions is analyzed. Finally, requirements on feeder fibers are discussed.
WDM-PON based on low-cost tunable lasers is a promising candidate for next-generation broadband o... more WDM-PON based on low-cost tunable lasers is a promising candidate for next-generation broadband optical access. For cost reasons, the tunable lasers must not be equipped with dedicated coolers and wavelength lockers. Then, correct tuning of the lasers must be ensured by cost-effective tuning mechanisms which are implemented and shared in the system context. In this paper, we describe several approaches to WDM-PON and how wavelength locking can be implemented.
Today, there is a major trend in metro access networks towards FTTx (Fiber-To-The-x, where x stan... more Today, there is a major trend in metro access networks towards FTTx (Fiber-To-The-x, where x stands for Home (H), Building (B), Curb, or Cabinet). Many agree that FTTH/FTTB will win mid- to long-term over other deployment scenarios because of a higher available bandwidth. Future metro networks need to maximize cost efficiency. This leads to requirements of reducing general OpEx (Operational Expenditures) and the numbers of active (concentrator) sites in the network in particular. This requires the consolidation of the three main metro area applications onto one common metro access & backhauling platform. These applications are (wireless, wireline) backhaul, business/enterprise access, and high bandwidth residential access. Whilst these applications today use different technologies (e.g., active point-to-point Ethernet, CWDM rings, VDSL and/or GPON) for the first mile, they need a converged infrastructure for efficient backhaul. In some networks, GPON is already being deployed for no...
2010 12th International Conference on Transparent Optical Networks, 2010
Efforts towards commercializing higher-speed optical transmission have demonstrated the need for ... more Efforts towards commercializing higher-speed optical transmission have demonstrated the need for advanced modulation formats, several of which require similar transceiver hardware architecture. Adaptive transceivers can be built which have different operational configurations controlled by software. These software-defined transceiver configurations support a set of specific modulation / demodulation formats, with respective data rates and tolerances to system impairments, as well as
Erste numerische Analysen und Vergleiche von dreistufigen Duobinär-und PAM-4-kodierten Signalen f... more Erste numerische Analysen und Vergleiche von dreistufigen Duobinär-und PAM-4-kodierten Signalen für die Übertragung mit Bitraten von 28 Gb/s bzw. 40 Gb/s in PONs der nächsten Generation auf Standardeinmodenfaser im C-Band werden vorgestellt. Hierbei werden Sender/Empfänger mit 10 GHz, 20 GHz, 28 GHz und 40 GHz betrachtet und die grundlegende Nutzbarkeit von kosteneffizienten bandbegrenzten Komponenten gezeigt. Weiter zeigt das Duobinär-Verfahren bei kleineren Distanzen bessere Empfindlichkeit, während dies bei größeren Distanzen für PAM-4 der Fall ist. Die analysierten Komponentenkosten sind für beide Verfahren ähnlich.
Spectrum-efficient optical transmission with bitrates of 400 Gb/s and beyond can be achieved usin... more Spectrum-efficient optical transmission with bitrates of 400 Gb/s and beyond can be achieved using flexible modulation with advanced DSPs. The technology options include modulation format, signal baud rate, number of subcarriers, and spectral bandwidth. A fine-granular spectral bandwidth requires a flexible WDM grid as recently defined by ITU-T. Transmission of a signal with multiple optical carriers, each potentially with their own set of modulation options, allows bandwidth-variable multi-flow transceivers. This can reduce the spectrum continuity constraint in the network. At the network layer, these new degrees of freedom create additional levels of complexity and constraints during network design, planning and operation. Which modulation constellation should be chosen for a new optical connection? What are the impacts on transmission reach, spectrum continuity constraints, and network utilization? Routing and spectrum assignment is becoming more complex, and the inevitable spect...
Over the last three years, a comprehensive techno-economic analysis of Next-Generation Optical Ac... more Over the last three years, a comprehensive techno-economic analysis of Next-Generation Optical Access (NGOA) has been performed in the EU FP7 project OASE (Optical Access Seamless Evolution). Several types of Passive as well as Active Optical Networks (PON/AON) have been investigated, with regard to system, cabling and fiber cost, and Operational Expenditures (OpEx) including operations, maintenance, and energy-consumption cost. The analysis was performed for several degrees of active-site consolidation as well as for several sustainable per-client bit rates. Here, the analysis of the relevant PON approaches is presented with focus on system and infrastructure costs. With increasing site-consolidation degree and per-client bit rate, the optimum solution shifts from G-PON / XG-PON1 towards WDM-based PON solutions.
Optical Metro Networks and Short-Haul Systems II, 2010
Fueled by the steady traffic increase in access and enterprise networks, optical metro networks r... more Fueled by the steady traffic increase in access and enterprise networks, optical metro networks represent a major growth opportunity for system vendors and component manufacturers. This paper reviews new developments from a technical and economic point of view. Topics such as network and node architectures, high-speed transmission, integrated optical/electronic switching as well as management and control will be discussed.
Optical Fiber Communication Conference/National Fiber Optic Engineers Conference 2011, 2011
1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network ... more 1. Introduction In order to satisfy the ever increasing demand for bandwidth, new access network solutions have to be found. One candidate to meet the requirements (bandwidth, reach, energy efficiency, and total cost (CapEx and OpEx)) for next-generation access (NGA) is ...
37th European Conference and Exposition on Optical Communications, 2011
ABSTRACT This paper investigates insertion loss, maximum reach, client count, power consumption, ... more ABSTRACT This paper investigates insertion loss, maximum reach, client count, power consumption, and associated cost of WDM-based Next-Generation PON under consideration of real-world fiber attenuation and penalties for patches, splices and in-house cabling.
Optical Fiber Communication Conference and National Fiber Optic Engineers Conference, 2009
ABSTRACT TCO of access networks is determined by operational expenditures, with energy cost being... more ABSTRACT TCO of access networks is determined by operational expenditures, with energy cost being one of the major contributors. We show that WDM-PON, although not lowest in capital expenditures, is a future-proof solution which minimizes TCO.
ABSTRACT Latest results of the Optical Access Seamless Evolution project on next-generation optic... more ABSTRACT Latest results of the Optical Access Seamless Evolution project on next-generation optical access enabling node consolidation will be presented. Based on a technical and economical assessment different architecture options will be compared.
ABSTRACT The paper deals with the subject of how to build a core network in the current technolog... more ABSTRACT The paper deals with the subject of how to build a core network in the current technology scenario. We start with an overview ofwhat we consider a core network, not in an abstract way but referring to real country situations, and pointing out the differentaspects conditioning its realisation – population distribution, territory shape, traffic characteristics. In the next section asummary of different network topologies is presented and briefly analysed – rings, meshes, loosely or tightly interconnected,with particular attention to the resilience aspect in case of faults. The following section is dedicated to a short presentation of thecurrent technology scenario and how it reflects on the network elements (NEs) offered on the market (OXC, OADM, PXC, etc).Finally, the question is posed: “What is the best way to implement a core network?” with the conclusion being that there is nosingle answer – each situation must be pursued on a case-by-case basis.
ABSTRACT We report a network-wide comparison of WDM-based Next-Generation PON access solutions, b... more ABSTRACT We report a network-wide comparison of WDM-based Next-Generation PON access solutions, based on an infrastructure, power consumption and system cost analysis, of a real-world network deployment scenario.
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Papers by Klaus Grobe