Adaptive bit rate variable cost-effective optical networks

Author(s):  
Christina Politi ◽  
Maki Nanou ◽  
George-Othon Glentis
Author(s):  
Laura Martín González ◽  
Sjoerd van der Heide ◽  
Xuwei Xue ◽  
John van Weerdenburg ◽  
Nicola Calabretta ◽  
...  

Adaptive Sliceable-Bandwidth Variable Transceivers (S-BVTs) are key enabler for future optical networks. In particular, those based on Discrete MultiTone (DMT) modulation and Direct Detection (DD) can be considered a flexible solution suitable to address the cost efficiency requirement of optical metro networks. In this paper, we propose to use this cost-effective S-BVT option/implementation in optical metro networks adopting switching nodes based on Semiconductor Optical Amplifier (SOA) technology. Bit loading (BL) and power loading (PL) algorithms are applied to the Digital Signal Processing (DSP) modules, to maximize the performance and/or the capacity as well as enhance the flexibility and adaptability of the system. Our analysis considers switching nodes based on SOAs with and without filtering elements and fiber spans of 25 km. We present the results up to 100 km, with and without SOA-based nodes. Firstly, we analyze the adaptive BVT transmission using the Margin Adaptive (MA) BL/PL algorithm at a fixed bit rate of 28 Gb/s. The possibility of controlling the SOAs current is a key factor to face the transmission impairments due to the fiber and the filtering elements. We also analyze the system considering Rate Adaptive (RA) transmission at a fixed target BER of 3.8·10−3, showing that a maximum capacity above 34 Gb/s can be achieved for a single span of 25 km. Although the cascading of filtering elements still constitutes a limiting factor, we show that an improvement of the net bit rate performance can be obtained thanks to the combined use of S-BVT and SOA technology at the switching nodes, resulting in a promising approach for designing future optical metro networks.


Photonics ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 24 ◽  
Author(s):  
Laura Martín González ◽  
Sjoerd van der Heide ◽  
Xuwei Xue ◽  
John van Weerdenburg ◽  
Nicola Calabretta ◽  
...  

Adaptive Sliceable-Bandwidth Variable Transceivers (S-BVTs) are key enablers for future optical networks. In particular, those based on Discrete MultiTone (DMT) modulation and Direct Detection (DD) can be considered a flexible solution suitable to address the cost efficiency requirement of optical metro networks. In this paper, we propose to use a cost-effective S-BVT option/implementation in optical metro networks adopting switching nodes based on Semiconductor Optical Amplifier (SOA) technology. Bit loading (BL) and power loading (PL) algorithms are applied to the Digital Signal Processing (DSP) modules, to maximize the performance and/or the capacity as well as enhance the flexibility and adaptability of the system. Our analysis considers switching nodes based on SOAs with and without filtering elements and fiber spans of 25 km. We present the results up to 100 km, with and without SOA-based nodes. Firstly, we analyze the adaptive BVT transmission using the Margin Adaptive (MA) BL/PL algorithm at a fixed bit rate of 28 Gb/s. The possibility of controlling the SOAs current is a key factor to face the transmission impairments due to the fiber and the filtering elements. We also analyze the system considering Rate Adaptive (RA) transmission at a fixed target Bit Error Rate (BER) of 3.8 × 10−3, showing that a maximum capacity above 34 Gb/s can be achieved for a single span of 25 km. Although the cascading of filtering elements still constitutes a limiting factor, we show that an improvement of the net bit rate performance can be obtained thanks to the combined use of BVT and SOA technology at the switching nodes, resulting in a promising approach for designing future optical metro networks.


Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 81
Author(s):  
Ramón Gutiérrez-Castrejón ◽  
Md Ghulam Saber ◽  
Md Samiul Alam ◽  
Zhenping Xing ◽  
Eslam El-Fiky ◽  
...  

We present a systematic comparison of PAM-2 (NRZ), Duobinary-PAM-2, PAM-4, and Duobinary-PAM-4 (duo-quaternary) signaling in the context of short-reach photonic communications systems using a Mach–Zehnder modulator as transmitter. The effect on system performance with a relaxed and constrained system’s opto-electronic bandwidth is analyzed for bit rates ranging from 20 to 116 Gb/s. In contrast to previous analyses, our approach employs the same experimental and simulation conditions for all modulation formats. Consequently, we were able to confidently determine the performance limits of each format for particular values of bit rate, system bandwidth, transmitter chirp, and fiber dispersion. We demonstrate that Duobinary-PAM-4 is a good signaling choice only for bandwidth-limited systems operating at relatively high speed. Otherwise, PAM-4 represents a more sensible choice. Moreover, our analysis put forward the existence of transition points: specific bit rate values where the BER versus bit rate curves for two different formats cross each other. They indicate the bit rate values where, for specific system conditions, switching from one modulation to another guarantees optimum performance. Their existence naturally led to the proposal of a format-selective transceiver, a component that, according to network conditions, operates with the most adequate modulation format. Since all analyzed modulations share similar implementation details, signaling switching is achieved by simply changing the sampling point and threshold count at the receiver, bringing flexibility to IM/DD-based optical networks.


2000 ◽  
Vol 11 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Qiao Chunming ◽  
Mei Yousong ◽  
Yoo Myungsik ◽  
Zhang Xijun

Author(s):  
Mário M. Freire ◽  
Paulo P. Monteiro ◽  
Henrique J.A. da Silva ◽  
José Ruela

Recently, Ethernet Passive Optical Networks (EPONs) have received a great amount of interest as a promising cost-effective solution for next-generation high-speed access networks. This is confirmed by the formation of several fora and working groups that contribute to their development, namely the EPON Forum (http://www. ieeecommunities.org/epon), the Ethernet in the First Mile Alliance (http://www.efmalliance.org), and the IEEE 802.3ah working group (http://www.ieee802. org/3/efm), which is responsible for the standardization process. EPONs are a simple, inexpensive, and scalable solution for high-speed residential access capable of delivering voice, high-speed data, and multimedia services to end users (Kramer, Mukherjee, & Maislos, 2003; Kramer & Pesavento, 2002; Lorenz, Rodrigues, & Freire, 2004; McGarry, Maier, & Reisslein, 2004; Pesavento, 2003). An EPON combines the transport of IEEE 802.3 Ethernet frames over a low-cost and broadband point-to-multipoint passive optical fibre infrastructure connecting the optical line terminal (OLT) located at the central office to optical network units (ONUs) usually located at the subscriber premises. In the downstream direction, the EPON behaves as a broadcast and select shared medium, with Ethernet frames transmitted by the OLT reaching every ONU. In the upstream direction, Ethernet frames transmitted by each ONU will only reach the OLT, but an arbitration mechanism is required to avoid collisions. This article provides an overview of EPONs focused several issues: EPON architecture, multipoint control protocol (MPCP), quality of service (QoS), and operations, administration, and maintenance (OAM) capability of EPONs.


Sign in / Sign up

Export Citation Format

Share Document