| 1. |
- Yaghoubi, Forough, 1988-, et al.
(författare)
-
Techno-economic and business feasibility analysis of 5G transport networks
- 2019
-
Ingår i: Optical and Wireless Convergence for 5G Networks. - : Wiley. ; , s. 273-295
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter introduces a techno-economic framework that provides a complete market analysis of the various business actors for any type of mobile access network deployments. It presents a case study where the proposed business feasibility framework is applied. The chapter presents a comprehensive techno-economic framework for estimating the total cost of ownership (TCO) of a backhaul network segment as well as for analyzing the business viability of a given wireless network deployment. It focuses on two backhaul technologies: microwave and fiber. The chapter addresses the framework proposed specifically only the backhaul segment, but it is general enough to also be applied to the other 5G transport solutions. It also presents the TCO module used in the proposed framework. The module covers both the Capital Expenditure and the Operational Expenditure aspects of the backhaul segment. The backhaul network is responsible for aggregating the users' traffic from the wireless access to the metro/backbone segment of the network.
|
|
| 2. |
- Chen, Qiman, et al.
(författare)
-
Flexible Service Chain Mapping in Server-Centric Optical Datacenter Networks
- 2018
-
Ingår i: 2018 ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE (ACP). - : IEEE. - 9781538661581
-
Konferensbidrag (refereegranskat)abstract
- We investigate flexible service chain mapping in server-centric optical terconnects, handling virtual network function (VNF) dependency operly. Blocking probability decreases by a factor of 10 when signing multiple VNFs in the same server is allowed.
|
|
| 3. |
- Chen, XÍ, et al.
(författare)
-
TDHQ Enabling Fine-granularity Adaptive Loading for SSB-DMT Systems
- 2018
-
Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers Inc.. - 1041-1135 .- 1941-0174. ; 30:19, s. 1687-1690
-
Tidskriftsartikel (refereegranskat)abstract
- In this letter, we introduce time domain hybrid quadrature amplitude modulation (TDHQ) for the single sideband (SSB) discrete multi-tone (DMT) systems. Experimental results reveal that with a single precoding set and the proposed adaptive loading algorithm, the TDHQ scheme can achieve finer granularity and therefore smoother continuous growth of data rate than that with the conventional quadrature amplitude modulation (QAM). Besides, thanks to the frame construction and the tailored mapping rule, the scheme with TDHQ has an obviously better peak to average power ratio (PAPR).
|
|
| 4. |
- Li, Jun, et al.
(författare)
-
Delay-aware bandwidth slicing for service migration in mobile backhaul networks
- 2019
-
Ingår i: Journal of Optical Communications and Networking. - : Institute of Electrical and Electronics Engineers Inc.. - 1943-0620 .- 1943-0639. ; 11:4, s. B1-B9
-
Tidskriftsartikel (refereegranskat)abstract
- Fog computing is expected to be integrated with communication infrastructure, giving rise to the concept of fog-enhanced radio access networks (FeRANs) to support various mission-critical applications. Such architecture brings computation capabilities closer to end users, thereby reducing the communication latency to access services. In the context of FeRAN, service migration is needed to tackle limited resources in a single fog node and to provide continuous service for mobile end users. To support service migration, high capacity and low latency are required in mobile backhaul networks. Passive optical networks can be a promising solution for such mobile back-haul, in which bandwidth is shared by both migration traffic and that which is not associated with service migration. In this paper, we propose a bandwidth slicing mechanism, in which the bandwidth can be provisioned to the migration traffic and non-migration traffic dynamically and effectively to meet their different delay requirements. Simulation results verify that the proposed delay-aware bandwidth slicing scheme can handle the migration traffic properly, i.e., sending it within a required time threshold, while limiting the impact of the migration traffic on the latency and jitter of the non-migration traffic, particularly that with high priority.
|
|
| 5. |
- Li, Jun, et al.
(författare)
-
Service Migration in Fog Computing Enabled Cellular Networks to Support Real-Time Vehicular Communications
- 2019
-
Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 7, s. 13704-13714
-
Tidskriftsartikel (refereegranskat)abstract
- Driven by the increasing number of connected vehicles and related services, powerful communication and computation capabilities are needed for vehicular communications, especially for real-time and safety-related applications. A cellular network consists of radio access technologies, including the current long-term evolution (LTE), the LTE advanced, and the forthcoming 5th generation mobile communication systems. It covers large areas and has the ability to provide high data rate and low latency communication services to mobile users. It is considered the most promising access technology to support real-time vehicular communications. Meanwhile, fog is an emerging architecture for computing, storage, and networking, in which fog nodes can be deployed at base stations to deliver cloud services close to vehicular users. In fog computing-enabled cellular networks, mobility is one of the most critical challenges for vehicular communications to maintain the service continuity and to satisfy the stringent service requirements, especially when the computing and storage resources are limited at the fog nodes. Service migration, relocating services from one fog server to another in a dynamic manner, has been proposed as an effective solution to the mobility problem. To support service migration, both computation and communication techniques need to be considered. Given the importance of protocol design to support the mobility of the vehicles and maintain high network performance, in this paper, we investigate the service migration in the fog computing-enabled cellular networks. We propose a quality-of-service aware scheme based on the existing handover procedures to support the real-time vehicular services. A case study based on a realistic vehicle mobility pattern for Luxembourg scenario is carried out, where the proposed scheme, as well as the benchmarks, are compared by analyzing latency and reliability as well as migration cost.
|
|
| 6. |
|
|
| 7. |
- Shen, Xiaoman, et al.
(författare)
-
Heterogeneous LTE/DSRC Approach to Support Real-time Vehicular Communications
- 2018
-
Ingår i: 2018 10TH INTERNATIONAL CONFERENCE ON ADVANCED INFOCOMM TECHNOLOGY (ICAIT). - : IEEE. ; , s. 122-127
-
Konferensbidrag (refereegranskat)abstract
- Vehicle-to-everything (V2X) communications have become a key enabler for future autonomous driving by providing sensing and cooperation abilities beyond traditional on-board sensors. The main candidate technologies for V2X communications are dedicated short range communication (DSRC)/IEEE 802.11p and long-term evolution (LTE), each of which has its own strengths and weaknesses. DSRC provides low-latency direct connectivity, but suffers from serious link degradation and reliability issues. On the other hand, LTE is able to provide high capacity data transmission, while its latency remains an issue due to the long transmission time interval. Integrating these two radio technologies as a heterogeneous solution is promising to complement each other and support V2X applications with differentiated service requirements. This paper proposes a service-aware radio access technology (RAT) selection algorithm that enables a heterogeneous LTE/DSRC solution, where LTE and/or DSRC are selected according to services. Each vehicle is assumed to be equipped with both LTE and DSRC interfaces. The heterogeneous solution selects RAT based on the services requirements with consideration of the networks performance. The solution is implemented with integration of the C-ITS standard and validated through the OMNet++ and SUMO based network simulator. A see-through scenario, where a fleet of vehicles require real-time video data sharing to assist efficient driving, is considered. The simulation results demonstrate that the proposed approach outperforms the purely DSRC approach significantly and is able to simultaneously support safety message transmission with low latency, video streaming with high bandwidth requirements, and other applications with different service requirements.
|
|
| 8. |
- Zhang, Z., et al.
(författare)
-
Accuracy enhancement of indoor visible light positioning using point-wise reinforcement learning
- 2019
-
Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : OSA - The Optical Society. - 9781943580538
-
Konferensbidrag (refereegranskat)abstract
- A point-wise reinforcement learning (PWRL) algorithm is proposed for a multi-detector based visible light positioning system. Experimental results demonstrate that the average positioning error is reduced up to 70% by employing the proposed PWRL.
|
|
| 9. |
- Zhang, Zhuo, et al.
(författare)
-
Iterative point-wise reinforcement learning for highly accurate indoor visible light positioning
- 2019
-
Ingår i: Optics Express. - : OPTICAL SOC AMER. - 1094-4087 .- 1094-4087. ; 27:16, s. 22161-22172
-
Tidskriftsartikel (refereegranskat)abstract
- Iterative point-wise reinforcement learning (IPWRL) is proposed for highly accurate indoor visible light positioning (VLP). By properly updating the height information in an iterative fashion, the IPWRL not only effectively mitigates the impact of non-deterministic noise but also exhibits excellent tolerance to deterministic errors caused by the inaccurate a priori height information. The principle of the IPWRL is explained, and the performance of the IPWRL is experimentally evaluated in a received signal strength (RSS) based VLP system and compared with other positioning algorithms, including the conventional RSS algorithm, the k-nearest neighbors (KNN) algorithm and the PWRL algorithm where iterations exclude. Unlike the supervised machine learning method, e.g., the KNN, whose performance is highly dependent on the training process, the proposed IPWRL does not require training and demonstrates robust positioning performance for the entire tested area. Experimental results also show that when a large height information mismatch occurs, the IPWRL is able to first correct the height information and then offers robust positioning results with a rather low positioning error, while the positioning errors caused by the other algorithms are significantly higher.
|
|
| 10. |
- Al-Awis, S. N., et al.
(författare)
-
Phenomenological formula for modelling of physical layer impairments in elastic optical networks
- 2015
-
Ingår i: Asia Communications and Photonics Conference, ACPC 2015. - Washington, D.C. : OSA. - 9781943580064
-
Konferensbidrag (refereegranskat)abstract
- An empirical modelling technique is introduced to estimate impact of physical layer impairments in elastic optical networks, which can be used to evaluate transmission quality. The model has been verified experimentally with accuracy beyond (97.3%).
|
|
| 11. |
|
|
| 12. |
- Archambault, Emile, et al.
(författare)
-
Routing and spectrum assignment in elastic filterless optical networks
- 2016
-
Ingår i: IEEE/ACM Transactions on Networking. - : IEEE. - 1063-6692 .- 1558-2566. ; 24:6, s. 3578-3592
-
Tidskriftsartikel (refereegranskat)abstract
- Elastic optical networking is considered a promising candidate to improve the spectral efficiency of optical networks. One of the most important planning challenges of elastic optical networks is the NP-hard routing and spectrum assignment (RSA) problem. In this paper, we investigate offline RSA in elastic filterless optical networks, which use a passive broadcast-and-select architecture to offer network agility. Here elastic optical network is referred to as the optical network that can adapt the channel bandwidth, data rate, and transmission format for each traffic demand in order to offer maximum throughput. In elastic filterless networks, the presence of unfiltered signals resulting from the drop-and-continue node architecture must be considered as an additional constraint in the RSA problem. In this paper, first the RSA problem in elastic filterless networks is formulated by using integer linear program (ILP) to obtain optimal solutions for small networks. Due to the problem complexity, two efficient RSA heuristics are also proposed to achieve suboptimal solutions for larger networks in reasonable time. Simulation results show that significant bandwidth savings in elastic filterless networks can be achieved compared to the fixed-grid filterless solutions. The proposed approach is further tested in multi-period traffic scenarios and combined with periodical spectrum defragmentation, leading to additional improvement in spectrum utilization of elastic filterless optical networks.
|
|
| 13. |
- Cao, Wei, et al.
(författare)
-
Interaction With Social Robots : Improving Gaze Toward Face but Not Necessarily Joint Attention in Children With Autism Spectrum Disorder
- 2019
-
Ingår i: Frontiers in Psychology. - : FRONTIERS MEDIA SA. - 1664-1078. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- It is widely recognized that robot-based interventions for autism spectrum disorders (ASD) hold promise, but the question remains as to whether social humanoid robots could facilitate joint attention performance in children with ASD. In this study, responsive joint attention was measured under two conditions in which different agents, a human and a robot, initiated joint attention via video. The participants were 15 children with ASD (mean age: 4.96 +/- 1.10 years) and 15 typically developing (TD) children (mean age: 4.53 +/- 0.90 years). In addition to analyses of fixation time and gaze transitions, a longest common subsequence approach (LCS) was employed to compare participants' eye movements to a predefined logical reference sequence. The fixation of TD toward agent's face was earlier and longer than children with ASD. Moreover, TD showed a greater number of gaze transitions between agent's face and target, and higher LCS scores than children with ASD. Both groups showed more interests in the robot's face, but the robot induced a lower proportion of fixation time on the target. Meanwhile participants showed similar gaze transitions and LCS results in both conditions, suggesting that they could follow the logic of the joint attention task induced by the robot as well as human. We have discussed the implications for the effects and applications of social humanoid robots in joint attention interventions.
|
|
| 14. |
- Cao, Yuan, et al.
(författare)
-
Multi-tenant secret-key assignment over quantum key distribution networks
- 2019
-
Ingår i: Optics Express. - : OPTICAL SOC AMER. - 1094-4087. ; 27:3, s. 2544-2561
-
Tidskriftsartikel (refereegranskat)abstract
- Quantum key distribution (QKD) networks are promising to progress towards widespread practical deployment over existing fiber infrastructures in the near future. Given the high cost and difficulty of deploying QKD networks, multi-tenancy becomes promising to improve cost efficiency for future QKD networks. In a multi-tenant QKD network, multiple QKD tenants can sham the same QKD network infrastructure to obtain secret keys for securing their data transfer. Since the secret-key resources are finite and precious in QKD networks, how to achieve efficient multi-tenant secret-key assignment (MTKA) to satisfy the secret-key demands of multiple QKD tenants over QKD networks becomes a significant problem. In this regard, this study addresses the MTKA problem over QKD networks. A new multi-tenant QKD network architecture is proposed based on software defined networking (SDN) and quantum key pool (QKP) techniques. A secret-key rate sharing scheme is presented and a heuristic algorithm is designed to implement efficient MTKA over QKD networks. A new performance metric, namely matching degree (MD) that reflects the balance between QKD network secret-key resources and QKD tenant requests, is defined and evaluated. Simulation studies indicate that high QKD tenant requests accommodation and efficient secret-key resource usage can be achieved via maximizing the value of MD.
|
|
| 15. |
|
|
| 16. |
- Cen, Min, et al.
(författare)
-
Advanced Fault-Monitoring Scheme for Ring-Based Long-Reach Optical Access Networks
- 2017
-
Ingår i: Journal of Lightwave Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0733-8724 .- 1558-2213. ; 35:10, s. 1876-1886
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel fiber fault-monitoring system for long-reach optical access networks based on a transmission-reflection analysis approach. By launching an un-modulated continuous-wave optical signal into the feeder ring and measuring the transmitted and reflected/backscattered optical powers, the proposed monitoring scheme is able to detect, identify, and localize any major fault (covering both reflective and nonreflective events) with a good spatial accuracy (<= 10 m) and a high detection speed (3 s). Both experimental and simulation results have demonstrated that the proposed system provides fiber monitoring functionality better than that obtained by the conventional methods.
|
|
| 17. |
- Cen, M., et al.
(författare)
-
Advanced Transmission-Reflection-Analysis (TRA) system for Long-Reach Passive Optical Network monitoring
- 2015
-
Ingår i: International Conference on Transparent Optical Networks. - : IEEE Computer Society. - 9781467378802
-
Konferensbidrag (refereegranskat)abstract
- Long-Reach Passive Optical Networks (LR-PONs) allows for extending the distance between the central office (CO) and end users from a few kilometers to several tens of kilometers and beyond. It in turn reduces the number of active equipment in the field, bringing potentially cost saving. However, due to its high capacity and large coverage, LR-PON becomes increasingly vulnerable to various failures. Therefore, network monitoring becomes extremely important to guarantee an appropriate level of network reliability and performance. In this paper, we report on an advanced LR-PON monitoring solution that can supervise the whole LR-PON ring section in a cost-effective manner. Instead of using the conventional optical time domain reflectometry (OTDR) approach, we implement multi wavelength Transmission-Reflection Analysis (nλ-TRA) as the monitoring technique. The TRA approach is based on the unique relationship between the optical powers transmitted and backscattered by the fiber for a given loss location. Since TRA only requires measuring the power levels of monitoring signals, it outperforms other conventional methods thanks to its superior detection speed and a simple system configuration. Both experimental results have demonstrated that the proposed system can reach high accuracy for fault localization.
|
|
| 18. |
- Cen, M., et al.
(författare)
-
Efficient monitoring for ring-based long-reach passive optical networks
- 2015
-
Ingår i: Optical Fiber Communication Conference, OFC 2015. - Washington, D.C. : The Optical Society. - 9781557529374
-
Konferensbidrag (refereegranskat)abstract
- An efficient monitoring scheme based on transmission-reflection analysis is proposed for long-reach passive optical networks. Both experimental simulation results have demonstrated that the proposed scheme provides better localization functionality than the conventional methods.
|
|
| 19. |
- Cen, Min, et al.
(författare)
-
Full monitoring for long-reach TWDM passive optical networks
- 2016
-
Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 24:14, s. 15782-15797
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a novel and simple fiber monitoring system based on multi-wavelength transmission-reflection analysis for long-reach time and wavelength division multiplexing passive optical networks. For the first time, the full localization functionality of long-reach passive optical networks is possible with the proposed monitoring scheme, including supporting fault detection, identification, and localization in both feeder and distribution fiber segments. By measuring the transmitted and reflected/backscattered optical powers launched by an unmodulated continuous-wave optical source, the proposed solution is able to supervise the network with good spatial accuracy, a high detection speed and a low impact on data traffic. Both the theoretical analysis and experimental validation show that the proposed scheme is capable of providing an accurate fault monitoring functionality for long-reach time and wavelength division multiplexing passive optical networks.
|
|
| 20. |
- Cen, M., et al.
(författare)
-
Full monitoring for Long-Reach TWDM Passive Optical Networks based on TRA technique
- 2016
-
Ingår i: International Conference on Transparent Optical Networks. - : IEEE Computer Society. - 9781509014675
-
Konferensbidrag (refereegranskat)abstract
- Long-Reach Passive Optical Networks (LR-PONs) consolidates of metropolitan and access networks by extending the distance between the Central Office (CO) and the end users, which in turn simplifies the network and potentially brings cost savings. With the explosively growing of data traffic, Time and Wavelength Division Multiplexing (TWDM) technology have also been employed in LR-PON to realize high capacity. However, due to high capacity and large coverage, the presence of a single failure may cause a huge loss of data and affect a large number of subscribers in LR-PON. Efficient network fault monitoring therefore becomes a key to improve the level of network reliability. In this paper, we report an advanced solution realizing fault detection, identification and localization in both feeder and distribution fiber segments of TWDM LR-PON. Instead of using the conventional optical time domain reflectometry (OTDR) approach, we implement multi wavelength Transmission-Reflection Analysis (nλ-TRA) as the monitoring technique, which is able to provide a good spatial accuracy and a high detection speed without interfering with the data traffic. Theoretical analysis and experimental validation demonstrate that the proposed scheme is capable of providing an accurate fault monitoring functionality.
|
|
| 21. |
- Chen, Cheng, et al.
(författare)
-
Application of benzodithiophene based A-D-A structured materials in efficient perovskite solar cells and organic solar cells
- 2016
-
Ingår i: Nano Energy. - : Elsevier. - 2211-2855. ; 23, s. 40-49
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, we have designed and synthesized a novel molecular material, BDT-C1, in which the core unit, benzodithiophene (BDT), was functionalized by thiophene (TP) and benzo-[c][1,2,5]-thiadiazole (BTZ) derivatives to generate extended pi-conjugation. BDT-C1 shows high hole mobility and high conductivity in its pristine form, in combination with appropriate energy level alignment with respect to [CH3NH3]PbI3 and PC70BM, qualifying the material as a good candidate for application both in perovskite solar cells (PSCs) as dopant-free hole transport material (HTM) and in OSCs as donor material. The champion PSCs based on BDT-C1 show an average conversion efficiency (PCE) of 13.4% (scan forward: 13.9%; scan backward: PCE=12.9%, scan rate: 10 mV/s). Although the average efficiency obtained is slightly lower than that of reference devices based on the well-known doped HTM Spiro-OMeTAD (13.7%), the BDT-C1 based devices exhibit better stability. Moreover, BDT-C1 as a donor material in OSCs also shows good performance in combination with PC70BM as acceptor material, and an efficiency of 6.1% was obtained. The present results demonstrate that BDT-C1 works well as both donor material in OSCs as well as dopant-free HTMs for efficient PSCs.
|
|
| 22. |
- Chen, Jiajia
(författare)
-
5G Transport networks : Capacity, latency and cost (invited)
- 2019
-
Ingår i: Optics InfoBase Conference Papers. - : OSA - The Optical Society. - 9781557528209 ; Part F133-Networks 2019
-
Konferensbidrag (refereegranskat)abstract
- This paper summarizes recent research on 5G transport networks addressing challenges on capacity, service migration and techno-economics that are brought by 5G new attributes, e.g., cloud radio access networks, diverse usage scenarios and heterogeneous deployments.
|
|
| 23. |
|
|
| 24. |
- Chen, Jiajia, et al.
(författare)
-
Optical Interconnects at the Top of the Rack for Energy-Efficient Data Centers
- 2015
-
Ingår i: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 53:8, s. 140-148
-
Tidskriftsartikel (refereegranskat)abstract
- The growing popularity of cloud and multimedia services is dramatically increasing the traffic volume that each data center needs to handle. This is driving the demand for highly scalable, flexible, and energy-efficient networks inside data centers, in particular for the edge tier, which requires a large number of interconnects and consumes the dominant part of the overall power. Optical fiber communication is widely recognized as the highest energy-and cost-efficient technique to offer ultra-large capacity for telecommunication networks. It has also been considered as a promising transmission technology for future data center applications. Taking into account the characteristics of the traffic generated by the servers, such as locality, multi-cast, dynamicity, and burstiness, the emphasis of the research on data center networks has to be put on architectures that leverage optical transport to the greatest possible extent. However, no feasible solution based on optical switching is available so far for handling the data center traffic at the edge tier. Therefore, apart from conventional optical switching, we investigate a completely different paradigm, passive optical interconnects, and aim to explore the possibility for optical interconnects at the top of the rack. In this article, we present three major types of passive optical interconnects and carry out a performance assessment with respect to the ability to host data center traffic, scalability, optical power budget, complexity of the required interface, cost, and energy consumption. Our results have verified that the investigated passive optical interconnects can achieve a significant reduction of power consumption and maintain cost at a similar level compared to its electronic counterpart. Furthermore, several research directions on passive optical interconnects have been pointed out for future green data centers.
|
|
| 25. |
- Chen, Jiajia, 1981
(författare)
-
Optical Networks in Data Centers
- 2019
-
Ingår i: OECC/PSC 2019 - 24th OptoElectronics and Communications Conference/International Conference Photonics in Switching and Computing 2019.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 26. |
- Cheng, Yuxin, et al.
(författare)
-
Centralized Control Plane for Passive Optical Top-of-Rack Interconnects in Data Centers
- 2016
-
Ingår i: 2016 IEEE Global Communications Conference, GLOBECOM 2016 - Proceedings. - : IEEE conference proceedings. - 9781509013289
-
Konferensbidrag (refereegranskat)abstract
- To efficiently handle the fast growing traffic inside data centers, several optical interconnect architectures have been recently proposed. However, most of them are targeting the aggregation and core tiers of the data center network, while relying on conventional electronic top-of-rack (ToR) switches to connect the servers inside the rack. The electronic ToR switches pose serious limitations on the data center network in terms of high cost and power consumption. To address this problem, we recently proposed a passive optical top-of-rack interconnect architecture, where we focused on the data plane design utilizing simple passive optical components to interconnect the servers within the rack. However, an appropriate control plane tailored for this architecture is needed to be able to analyze the network performance, e.g., packet delay, drop rate, etc., and also obtain a holistic network design for our passive optical top-of-rack interconnect, which we refer to as POTORI. To fill in this gap, this paper proposes the POTORI control plane design which relies on a centralized rack controller to manage the communications inside the rack. To achieve high network performance in POTORI, we also propose a centralized medium access control (MAC) protocol and two dynamic bandwidth allocation (DBA) algorithms, namely Largest First (LF) and Largest First with Void Filling (LFVF). Simulation results show that POTORI achieves packet delays in the order of microseconds and negligible packet loss probability under realistic data center traffic scenarios.
|
|
| 27. |
- Cheng, Yuxin
(författare)
-
Optical Interconnects for Next Generation Data Centers : Architecture Design and Resource Allocation
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The current data center architectures based on blade servers and elec- tronic packet switches face several problems, e.g., limited resource utilization, high power consumption and cost, when handling the rapidly growing of data traffic. Optical networks offering ultra-high capacity and requiring low energy consumption are considered as a good option to address these problems. This thesis presents new data center architectures based on optical interconnects and transmissions, and evaluates performance by extensive simulations.The first main contribution of the thesis is to introduce a passive optical top-of-rack interconnect (POTORI) architecture. The data plane of POTORI mainly consists of passive components to interconnect the servers within the rack. Using the passive components makes it possible to significantly reduce power consumption while achieving high reliability in a cost-efficient way. In addition, the POTORI’s control plane is based on a centralized controller, which is responsible for coordinating the communications among the servers in the rack. A cycle-based medium access control (MAC) protocol and a dy- namic bandwidth allocation (DBA) algorithm are designed for the POTORI to efficiently manage the exchange of control messages and the data transmis- sion inside the rack. Simulation results show that under realistic DC traffic scenarios, the POTORI with the proposed DBA algorithm is able to achieve an average packet delay below 10 μs with the use of fast tunable optical transceivers.The second main contribution of the thesis is to investigate rack-scale disaggregated data center (DDC) architecture for improving resource utiliza- tion. In contrast to the traditional DC with blade servers that integrate various types of resources (e.g., central processing unit (CPU), memory) in a chassis, the rack-scale DDC contains fully decoupled resources held on differ- ent blades, referred to as resource blades. The resource blades are required to be interconnected within the rack by an ultra-high bandwidth optical in- terconnect through the optical interfaces (OIs). A resource allocation (RA) algorithm is proposed to efficiently schedule the resources in the DDC for virtual machine requests. Results show that with sufficient bandwidth on the OIs, the rack-scale DDC with the proposed RA algorithm can achieve 20% higher resource utilization and make 30% more revenue comparing to the traditional DC.
|
|
| 28. |
- Cheng, Yuxin
(författare)
-
Passive Optical Top-of-Rack Interconnect for Data Center Networks
- 2017
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Optical networks offering ultra-high capacity and low energy consumption per bit are considered as a good option to handle the rapidly growing traffic volume inside data center (DCs). However, most of the optical interconnect architectures proposed for DCs so far are mainly focused on the aggregation/core tiers of the data center networks (DCNs), while relying on the conventional top-of-rack (ToR) electronic packet switches (EPS) in the access tier. A large number of ToR switches in the current DCNs brings serious scalability limitations due to high cost and power consumption. Thus, it is important to investigate and evaluate new optical interconnects tailored for the access tier of the DCNs.We propose and evaluate a passive optical ToR interconnect (POTORI) architecture for the access tier. The data plane of the POTORI consists mainly of passive components to interconnect the servers within the rack as well as the interfaces toward the aggregation/core tiers. Using the passive components makes it possible to significantly reduce power consumption while achieving high reliability in a cost-efficient way.Meanwhile, our proposed POTORI’s control plane is based on a centralized rack controller, which is responsible for coordinating the communications among the servers in the rack. It can be reconfigured by software-defined networking (SDN) operation. A cycle-based medium access control (MAC) protocol and a dynamic bandwidth allocation (DBA) algorithm are designed for the POTORI to efficiently manage the exchange of control messages and the data transmission inside the rack.Simulation results show that under realistic DC traffic scenarios, the POTORI with the proposed DBA algorithm is able to achieve an average packet delay below 10 μs with the use of fast tunable optical transceivers. Moreover, we further quantify the impact of different network configuration parameters on the average packet delay.
|
|
| 29. |
- Cheng, Yuxin, et al.
(författare)
-
POTORI : A Passive Optical Top-of-Rack Interconnect Architecture for Data Centers
- 2017
-
Ingår i: Journal of Optical Communications and Networking. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0620 .- 1943-0639. ; 9:5, s. 401-411
-
Tidskriftsartikel (refereegranskat)abstract
- Several optical interconnect architectures inside data centers (DCs) have been proposed to efficiently handle the rapidly growing traffic demand. However, not many works have tackled the interconnects at top-of-rack (ToR), which have a large impact on the performance of the data center networks (DCNs) and can introduce serious scalability limitations due to their high cost and power consumption. In this paper, we propose a passive optical ToR interconnect architecture (POTORI) to replace the conventional electronic packet switch (EPS) in the access tier of DCNs. In the data plane, POTORI relies on a passive optical coupler to interconnect the servers within the rack and interfaces toward the aggregation/core tiers. The POTORI control plane is based on a centralized rack controller responsible for managing the communications among the servers in the rack. We propose a cycle-based medium access control (MAC) protocol to efficiently manage the exchange of control messages and the data transmission inside the rack. We also introduce and evaluate a dynamic bandwidth allocation algorithm for POTORI, namely largest first (LF). Extensive simulation results show that, with the use of fast tunable optical transceivers, POTORI and the proposed LF strategy are able to achieve an average packet delay below 10 μs under realistic DC traffic scenarios, outperforming conventional EPSs. On the other hand, with slower tunable optical transceivers, a careful configuration of the network parameters (e.g., maximum cycle time of the MAC protocol) is necessary to obtain a good network performance in terms of the average packet delay.
|
|
| 30. |
- Cheng, Yuxin, et al.
(författare)
-
Reliability Analysis of Interconnects at Edge Tier in Datacenters
- 2015
-
Ingår i: 2015 17th International Conference on Transparent Optical Networks (ICTON). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781467378802
-
Konferensbidrag (refereegranskat)abstract
- The growing popularity of cloud based applications is drastically increasing the traffic volume that datacenters have to handle. This brings the need for scalable, reliable, and energy-efficient interconnection networks inside the datacenters. Optical communication has been considered as a promising technology for datacenter applications due to its high energy- and cost-efficiency at ultra-high capacity. A typical datacenter interconnection network includes several tiers. Figure 1 shows an example with three tiers: edge, aggregation and core. Due to the large number of active devices on top of the rack (ToR) energy consumption at the edge tier is dominating the overall power consumed by all the switches within the datacenter [1-2]. Several passive optical interconnect approaches [2-4] have been proposed showing that replacing active optical devices by passive ones is possible to significantly reduce both the hardware cost and energy consumption, achieve lower maintenance complexity and offer a sufficient level of scalability. [GRAPHICS] Furthermore, several topologies, e.g., fat-tree [5], Quartz [6], are investigated in order to improve the resiliency and scalability, particularly for large-scale datacenters. However, it should be noted that the redundancy for these proposed topologies is often added in the aggregation and core tiers rather than the edge tier, due to the cost issue. Although passive optical ToR solution by nature could provide better reliability performance than its active counterpart, the intra-rack communication may still need survivability strategies to meet very high connection availability requirement. For instance, the required availability of fault-tolerant datacenter infrastructure (including electrical power supply, storage and distribution facilities) should be higher than 99.995% [7]. Then the expected availability for any connection established within the datacenter needs to be even higher, since the communication system is only a part of the site infrastructure. In this regard, we analyse reliability performance of optical interconnects and identify the key part to be protected. Based on it, we propose some reliable passive optical interconnects for the edge tier of the datacenter interconnection networks. They can achieve ultra-high connection availability for intra-rack communications and adapt to any topology, e.g., fat-tree and Quartz, designed to increase scalability and reliability performance for the overall datacenter network.
|
|
| 31. |
- Cheng, Yuxin, et al.
(författare)
-
Reliable and Cost Efficient Passive Optical Interconnects for Data Centers
- 2015
-
Ingår i: IEEE Communications Letters. - : IEEE Communications Society. - 1089-7798 .- 1558-2558. ; 19:11, s. 1913-1916
-
Tidskriftsartikel (refereegranskat)abstract
- To address the sustainability, scalability, and reliability problems that data centers are currently facing, we propose three passive optical interconnect (POI) architectures on top of the rack. The evaluation results show that all three architectures offer high reliability performance (connection availability for intra-rack interconnections higher than 99.999%) in a cost-efficient way.
|
|
| 32. |
|
|
| 33. |
- Chiaraviglio, Luca, et al.
(författare)
-
Is Green Networking Beneficial in Terms of Device Lifetime?
- 2015
-
Ingår i: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 53:5, s. 232-240
-
Tidskriftsartikel (refereegranskat)abstract
- This article analyzes the impact that sleep mode (SM)-based green strategies have on the reliability performance of optical and cellular network elements. First, we consider a device in isolation (i. e., not plugged into a network in operation), showing how operational temperature and temperature variations, both introduced by SM, impact its lifetime. We then evaluate, from an operational cost perspective, the impact of these lifetime variations, showing that some devices are critical, that is, their achievable energy savings might not cover the potential additional reparation costs resulting from being put in SM too frequently. Moreover, we present a model for evaluating the impact of SM on the lifetime of a device plugged into an operational network. The analysis considers two case studies (one based on the optical backbone and one on cellular networks) showing that the lifetime of a device is influenced by both the hardware parameters, which depend on the specific design of the device, and the SM parameters, which instead depend on the energy-efficient algorithm used, the network topology, and the traffic variations over time. Our results show that (i) the changes in the operational temperature and the frequency of their variation are two crucial aspects to consider while designing a SM-based green strategy, and (ii) the impact of a certain SM-based strategy on the lifetime of network devices is not homogeneous (i. e., it can vary through the network).
|
|
| 34. |
- Estarán, Jose, et al.
(författare)
-
140/180/204-Gbaud OOK Transceiver for Inter- and Intra-Data Center Connectivity
- 2019
-
Ingår i: Journal of Lightwave Technology. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0733-8724 .- 1558-2213. ; 37:1, s. 178-187
-
Tidskriftsartikel (refereegranskat)abstract
- We report on an on-off keying intensity-modulation and direct-detection C-band optical transceiver capable of addressing all datacenter interconnect environments at well-beyond 100Gbaud. For this, the transmitter makes use of two key InP technologies: a 2:1 double heterojunction bipolar transistor selector multiplexer and a monolithically integrated distributed-feedback laser traveling-wave electro-absorption modulator, both exceeding 100-GHz of 3-dB analog bandwidth. A pre-amplified 110-GHz PIN photodiode prior to a 100-GHz analog-to-digital converter complete the ultra-high bandwidth transceiver module; the device under study. In the experimental work, which discriminates between intra- and inter-data center scenarios (dispersion unmanaged 120, 560, 960m; and dispersion-managed 10, and 80km of standard singlemode fiber), we evaluate the bit-error rate evolution against the received optical power at 140, 180, and 204Gbaud on-off keying for different equalization configurations (adaptive linear filter with and without the help of short-memory sequence estimation) and forward error correction schemes (hard-decision codes with 7% and 20% overhead); drawing conclusions from the observed system-level limitations of the respective environments at this ultra-high baudrate, as well as from the operation margins and sensitivity metrics. From the demonstration, we highlight three results: successful operation with >6-dB sensitivity margin below the 7% error-correction at 140Gbaud over the entire 100m-80km range with only linear feed-forward equalization. Then the transmission of a 180Gbaud on-off-keying carrier over 80km considering 20% error-correction overhead. And finally, 10-km communication at 204Gbaud on-off keying with up to 6dB sensitivity margin, and regular 7%-overhead error-correction.
|
|
| 35. |
- Fiorani, Matteo, et al.
(författare)
-
Optical spatial division multiplexing for ultra-high-capacity modular data centers
- 2016
-
Ingår i: 2016 Optical Fiber Communications Conference and Exhibition, OFC 2016. - Washington, D.C. : Institute of Electrical and Electronics Engineers (IEEE). - 9781943580071
-
Konferensbidrag (refereegranskat)abstract
- We propose and evaluate four optical interconnect architectures based on spatial division multiplexing for ultra-high capacity modular data centers. It is shown in which way the best option depends on the network load and size.
|
|
| 36. |
- Fiorani, Matteo, et al.
(författare)
-
Spatial division multiplexing for high capacity optical interconnects in modular data centers
- 2017
-
Ingår i: Journal of Optical Communications and Networking. - : Optical Society of America. - 1943-0620 .- 1943-0639. ; 9:2, s. A143-A153
-
Tidskriftsartikel (refereegranskat)abstract
- Modular design has recently emerged as an efficient solution to build large data center (DC) facilities. Modular DCs are based on stand-Alone prefabricated modules (i.e., PODs) that can be easily installed and interconnected. PODs can generate a large amount of traffic and thus require an ultra-high-capacity interconnection network. However, current electronic and optical interconnect architectures applied to modular DCs may experience major scalability problems in terms of high energy consumption and cabling complexity. To address these problems, we investigate five optical interconnect architectures based on spatial division multiplexing (SDM), and for each architecture, we propose a resource allocation strategy. We also present an extensive comparison among the SDM architectures in terms of cost and performance (i.e., blocking probability and throughput), with the objective to find the architecture offering the best trade-off between cost and performance for given DC sizes and traffic load values. Our results demonstrate that, in small modular DCs with low traffic load, an architecture based only on SDM is the best option, while in medium DCs with medium traffic load, an architecture based on coupled SDM and flexgrid wavelength division multiplexing (WDM) with spectral flexibility is the best solution. Finally, for large DCs with high traffic load values, the best trade-off between cost and performance is achieved by an SDM architecture that is based on uncoupled SDM and flexgrid WDM.
|
|
| 37. |
- Forzati, Marco, et al.
(författare)
-
Next-generation optical access seamless evolution : Concluding results of the European FP7 Project OASE
- 2015
-
Ingår i: Journal of Optical Communications and Networking. - : Institute of Electrical and Electronics Engineers Inc.. - 1943-0620 .- 1943-0639. ; 7:2, s. 109-123
-
Tidskriftsartikel (refereegranskat)abstract
- Increasing bandwidth demand drives the need for next-generation optical access (NGOA) networks that can meet future end-user service requirements. This paper gives an overview of NGOA solutions, the enabling optical access network technologies, architecture principles, and related economics and business models. NGOA requirements (including peak and sustainable data rate, reach, cost, node consolidation, and open access) are proposed, and the different solutions are compared against such requirements in different scenarios (in terms of population density and system migration). Unsurprisingly, it is found that different solutions are best suited for different scenarios. The conclusions drawn from such findings allow us to formulate recommendations in terms of technology, strategy, and policy. The paper is based on the main results of the European FP7 OASE Integrated Project that ran between January 1, 2010 and February 28, 2013.
|
|
| 38. |
- Gabrielsson, Erik, et al.
(författare)
-
Dipicolinic acid : a strong anchoring group with tunable redox and spectral behavior for stable dye-sensitized solar cells
- 2015
-
Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 51:18, s. 3858-3861
-
Tidskriftsartikel (refereegranskat)abstract
- Dipicolinic acidwas investigated as a new anchoring group for DSSCs. A pilot dye (PD2) bearing this new anchoring group was found to adsorb significantly stronger to TiO2 than its cyanoacrylic acid analogue. The electrolyte composition was found to have a strong effect on the photoelectrochemical properties of the adsorbed dye in the device, allowing the dye LUMO energy to be tuned by 0.5 eV. Using a pyridine-free electrolyte, panchromatic absorption of the dye on TiO2 extending to 900 nm has been achieved. Solar cells using PD2 and a Co(bpy)(3) based electrolyte showed unique stability under simulated sunlight and elevated temperatures.
|
|
| 39. |
- Gong, Y., et al.
(författare)
-
Crosstalk-aware multiple-AWG based optical interconnects for datacenter networks
- 2018
-
Ingår i: Optics Communications. - : Elsevier. - 0030-4018 .- 1873-0310. ; 426, s. 151-157
-
Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a crosstalk-aware passive optical interconnect architecture based on multiple arrayed waveguide gratings (AWGs). With two-stage cascaded AWGs, it can realize the communications not only within but also among the clusters for large-scale datacenters. To overcome serious crosstalk in multiple-AWG based optical interconnects, crosstalk suppression schemes are proposed. Proof-of-concept experiments are carried out to verify the necessity and feasibility of the proposed crosstalk suppression schemes for multiple-AWG based optical interconnects.
|
|
| 40. |
- Gong, Yu, et al.
(författare)
-
Passive optical interconnects at top of the rack : offering high energy efficiency for datacenters
- 2015
-
Ingår i: Optics Express. - 1094-4087. ; 23:6, s. 7957-7970
-
Tidskriftsartikel (refereegranskat)abstract
- This paper introduces a new concept, namely passive optical interconnect at top of the rack in the datacenter networks, and investigates several architectures, which use only passive optical components to interconnect different servers. In such a manner, the proposed schemes are able to offer higher bandwidth and significantly improve energy efficiency compared to their electronic counterpart that is based on commodity switches. The proposed passive optical interconnect schemes are experimentally demonstrated in order to validate the transmission performance. Besides, an assessment in terms of energy consumption and cost has also been carried out, which shows our proposed concept can significantly outperform the conventional commodity switches on energy efficiency while keeping the cost in the similar level.
|
|
| 41. |
- Hong, Xuezhi, et al.
(författare)
-
1.55-μm EML-based DMT transmission with nonlinearity- aware time domain super-nyquist image induced aliasing
- 2017
-
Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : OSA - The Optical Society. - 9781557528209
-
Konferensbidrag (refereegranskat)abstract
- We experimentally demonstrate a DMT transmission system with 1.55-μm EML using nonlinearity-aware time domain super-Nyquist image induced aliasing. Compared with linear equalization, the capacity is improved by ~16.8%(33.1%) with proposed method for 4(40) km transmission. © 2017 OSA.
|
|
| 42. |
|
|
| 43. |
- Hong, Xuezhi, et al.
(författare)
-
Passive Optical Interconnects Based on Cascading Wavelength Routing Devices for Datacenters : A Cross-Layer Perspective
- 2017
-
Ingår i: Journal of Optical Communications and Networking. - : Optical Society of America. - 1943-0620 .- 1943-0639. ; 9:4, s. C45-C53
-
Tidskriftsartikel (refereegranskat)abstract
- A general passive optical interconnect (POI) architecture based on cascading wavelength routing devices is proposed for datacenters. An analysis shows that with a proper port configuration, the logic topology of the proposed POI is equivalent to a DCell network, which has rich connectivity, leading to a high fault tolerance. Compared with the existing arrayed waveguide grating (AWG)-based architecture, such as H-LION, the proposed architecture has a higher AWG port utilization and lower cabling complexity that result in better scalability. Meanwhile, an impairment-aware scalability analysis is carried out to estimate the impact of in-band crosstalk on the size of the POI. Furthermore, a cross-layer investigation of the proposed POI provides a guideline to select proper physical-layer implementations, including optical interface structure and design of the transceiver, for acceptable network performance. The numerical results reveal that, with a moderate number of shortest paths K and degrees of node D, (a) the bidirectional optical interface is more suitable for large-scale datacenter networks than the unidirectional one, (b) an array of fixed receivers can be replaced by just a small number of tunable receivers with negligible degradation in network performance, and (c) decreasing 50% of the tuning range of the receivers causes only a minor increase of blocking probability, which demonstrates a good balance between the complexity of the transceiver design and network performance.
|
|
| 44. |
- Hong, Yuanyuan, et al.
(författare)
-
Elastic all-optical multi-hop interconnection in data centers with adaptive spectrum allocation
- 2017
-
Ingår i: Optics Communications. - : Elsevier. - 0030-4018 .- 1873-0310. ; 383, s. 478-484
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, a novel flex-grid all-optical interconnect scheme that supports transparent multi-hop connections in data centers is proposed. An inter-rack all-optical multi-hop connection is realized with an optical loop employed at flex-grid wavelength selective switches (WSSs) in an intermediate rack rather than by relaying through optical-electric-optical (O-E-O) conversions. Compared with the conventional O-E-O based approach, the proposed all-optical scheme is able to off-load the traffic at intermediate racks, leading to a reduction of the power consumption and cost. The transmission performance of the proposed flex-grid multi-hop all-optical interconnect scheme with various modulation formats, including both coherently detected and directly detected approaches, are investigated by Monte-Carlo simulations. To enhance the spectrum efficiency (SE), number-of-hop adaptive bandwidth allocation is introduced. Numerical results show that the SE can be improved by up to 33.3% at 40 Gbps, and by up to 25% at 100 Gbps. The impact of parameters, such as targeted bit error rate (BER) level and insertion loss of components, on the transmission performance of the proposed approach are also explored. The results show that the maximum SE improvement of the adaptive approach over the non-adaptive one is enhanced with the decrease of the targeted BER levels and the component insertion loss.
|
|
| 45. |
- Hong, Y., et al.
(författare)
-
Flex-grid all-optical interconnect supporting transparent multi-hop connection in data centers
- 2015
-
Konferensbidrag (refereegranskat)abstract
- In this paper a novel flex-grid all-optical interconnect scheme is proposed for data center, where a transparent multi-hop connection can be realized by using optical bypass rather than going through optical-electric-optical conversions, enhancing energy efficiency for inter-rack communications. Moreover, elastic spectrum allocation is adopted in the proposed scheme to increase the resource utilization and scalability. Transmission performance evaluation has been carried out to verify the feasibility of the proposed scheme.
|
|
| 46. |
- Hong, Yuanyuan, et al.
(författare)
-
Hybrid Routing and Adaptive Spectrum Allocation for Flex-Grid Optical Interconnects
- 2018
-
Ingår i: Journal of Optical Communications and Networking. - : Optical Society of America. - 1943-0620 .- 1943-0639. ; 10:5, s. 506-514
-
Tidskriftsartikel (refereegranskat)abstract
- A hybrid routing scheme with an adaptive spectrum assignment is proposed for flex-grid all-optical core switch supporting multihop transparent paths in data center networks. Compared with conventional spectrum assignment algorithms (RSA) developed for a multihop network with optical-electric-optical (OEO) conversion in every hop (i.e., RSA for EO) and that devised for an all-optical multihop network (i.e., RSA for AO), the present RSA algorithm provides better utilization of network resources. Being aware of the all-optical bypass path in hopping, the proposed RSA reduces the blocking probability due to lack of bandwidth-tunable transceivers, which is the major reason for blocking for an RSA for the EO. Similar to the RSA for the AO, the proposed RSA is compatible with the number-of-hops adaptive spectrum assignment, which improves spectrum efficiency. On the other hand, the new algorithm enhances connectivity by eliminating the number-of-hops limitation, which severely constrains the performance of RSA for the AO. Simulations for the system are carried out to investigate the performance of the new algorithm. The impacts of various parameters, such as traffic load, ratio of connection requests with different data rates, and resource configuration on the link cost, are studied in terms of network blocking probability (BP). The achievable traffic load of the proposed RSA under varied connection degrees (i.e., the maximum number of ports that one rack has in order to connect to the core switch) and number of racks is also assessed to keep BP no more than 0.1. The results show that the proposed RSA with appropriate cost functions outperforms the EO and AO, which implies that it has the highest scalability.
|
|
| 47. |
- Hu, H., et al.
(författare)
-
TuB4.1-chip based thz emitter for ultra-high speed THz wireless communication (Invited)
- 2019
-
Ingår i: IEEE Photonics Society Summer Topical Meeting Series 2019, SUM 2019. - : Institute of Electrical and Electronics Engineers Inc.. - 9781728105970
-
Konferensbidrag (refereegranskat)abstract
- By using a monolithically integrated dual-distributed feedback (DFB) laser chip attached to a photomixing uni-Travelling carrier photodiode (UTC-PD) with a THz antenna, single-channel THz photonic-wireless transmission system with a net rate of 131 Gbit/s over a wireless distance of 10.7 m has been achieved.
|
|
| 48. |
- Jia, S., et al.
(författare)
-
Integrated Dual-DFB Laser for 408 GHz Carrier Generation Enabling 131 Gbit/s Wireless Transmission over 10.7 Meters
- 2019
-
Ingår i: 2019 Optical Fiber Communications Conference and Exhibition, OFC 2019 - Proceedings. - Washington, D.C. : Institute of Electrical and Electronics Engineers Inc.. - 9781943580538
-
Konferensbidrag (refereegranskat)abstract
- A monolithically integrated dual-DFB laser generates a 408 GHz carrier used for demonstrating a record-high single-channel bit rate of 131 Gbit/s transmitted over 10.7 m. 16-QAM-OFDM modulation and specific nonlinear equalization techniques are employed
|
|
| 49. |
|
|
| 50. |
- Kerrebrouck, Joris Van, et al.
(författare)
-
726.7-Gb/s 1.5-μm single-mode VCSEL discrete multi-tone transmission over 2.5-km multicore fiber
- 2018
-
Ingår i: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings. - : Institute of Electrical and Electronics Engineers Inc.. - 9781943580385 ; , s. 1-3
-
Konferensbidrag (refereegranskat)abstract
- A 107Gb/s net-rate DMT optical signal was generated using a single-mode long-wavelength VCSEL with a modulation bandwidth of 23 GHz. We experimentally demonstrated a total net-rate up to 726.7Gb/s at 1.5μm over 2.5km 7-core dispersion-uncompensated MCF.
|
|
