Simulations of Grant Allocation in NG-PON2 Networks Using OPNET Modeler

Abstract

PONs (Passive Optical Networks) are the most promising networks for the future. In 1998, the first standard of PONs was developed. Since that time, quality of optical transmissions and technologies has been massively improved and today's standards are capable of transferring an enormous amount of data. For example, NG-PON2 networks are able to transfer up to 40 Gbit/s, which means these networks provide subscribers with a symmetric bandwidth up to 10 Gbit/s using 4 different wavelengths. The higher transmission speeds are required, the more sophisticated bandwidth allocation reflecting requirements of each ONU (Optical Network Unit) in real-time is necessary. This article deals with implementation of NG-PON2 networks using OPNET Modeler and simulations of static and dynamic grants allocations. We also present a modification of dynamic bandwidth allocation for increasing the free bandwidth of idle ONU to heavily loaded ONU(s). We propose a simplified NG-PON2 (Next-Generation PON stage 2) network, for example, activation machine for ONUs is not implemented. At present, OPNET Modeler is being used to simulate EPON (Ethernet PON) networks that use a different approach for data transmission. Thanks to its own implementation, basic data transmission in NG-PON2 networks, and simulations of algorithms for dynamic bandwidth allocation can be achieved.

Efficiency Tests of DBA Algorithms in XG-PON

“…We also dealt with DBA algorithms in next-generation passive optical network stage 2 (NG-PON2) networks [20,21]. First, we introduced an implementation of the transmission convergence (TC) layer because the DBA uses the TC layer for allocation structures with grant size, start time, stop time, and other fields.…”

Utilization of 10 Gbps DWDM System with Duobinary Modulation into Passive Optical Network

“…Upstream is used mainly for voice services and works in the range of 1290-1310 nm wavelength. However, these ranges may vary depending on the specification of PON [4], [5], [6].…”

“…Channel transmitters employed with DWDM technology require a control mechanism to enable them to meet requirements on frequency stability. Recommendation G.694.1 defines a variety of fixed channel spacings -12.5 GHz, 25 GHz, 50 GHz and 100 GHz as well as flexible spacing [3], [6]. CWDM defines 18 wavelength channels (1271 -1611 nm) with channel spacing of 20 nm.…”

“…The article by Ivaniga et al [5] shows the influence of four wave mixing (FWM) in high spectral DWDM system with arrayed waveguide grating (AWG) using different channel spacing to influence channel crosstalk. This paper is also part of a continuous research, part of which is an article [6] presented by authors at ICCC 2018. In this article authors deal with the implementation of advanced optical modulation formats based on optical IQ modulator in high spectral efficiency DWDM system with transmission rate of 20 Gbps per channel.…”