Multi-rate (100G/40G/10G) Transport Over Deployed Optical Networks

Abstract

In this paper we describe the boundary conditions for upgrading existing 10G optical transport networks with 40G and 100G channels and the operational issues in multi-rate optical networks.

Nonlinear penalties in long-haul optical networks employing dynamic transponders

“…Compensation of many of the linear and nonlinear fibre impairments can be achieved by employing electronic signal processing using digital back-propagation (DBP) [9][10][11]. Although the future potential of nonlinear impairment compensation using DBP in a dynamic optical network is unclear due to its significant computational burden and limited access to the full dense wavedivision multiplexing band, simplification of nonlinear DBP algorithm using single-channel processing at the receiver has already commenced [12,13] In such a dynamic network, there is a large range of options to provide the desired flexibility including symbol rate [14], sub-carrier multiplexing [15], network configuration [16] and signal constellation [3]. In this paper we focus on the signal constellation and report the impact of periodic addition of PM-mQAM (m = 4, 16, 64, 256) transmission schemes on existing PM-4QAM traffic in a 28 Gbaud WDM optical network with a maximum transparent optical path of 9,600 km.…”

Nonlinear Penalties in Dynamic Optical Networks Employing Autonomous Transponders

“…In this letter we extend the work of [4,5] modulated (PM-mQAM) channels on existing PM-4QAM traffic in a 28 Gbaud WDM optical network with a maximum transparent optical path of 9,600 km and for a varying number of reconfigurable add drop multiplexer (ROADM) configurations. We first optimize the transmission distance suitable to enable a suitable forward error correction (FEC) performance margin (at bit-error rate of 3.8x10 -3 ) for the network traffic given various modulation schemes at a fixed launch power of -1 dBm.…”

“…One such challenge is associated with the nonlinear transmission impairments which strongly connect the achievable channel reach to a given modulation format and symbol-rate [1,3]. In particular, it has been reported recently that the upgrade of a wavelength channel to a high spectral efficiency format is constrained by nonlinear cross-talk from the existing on-off keyed traffic [4,5]. Subsequent evolution will require the introduction of high bit-rate traffic (e.g.…”

Nonlinear and ROADM induced penalties in 28 Gbaud dynamic optical mesh networks employing electronic signal processing

“…One such challenge is associated with the nonlinear transmission impairments [10][11][12][13]. In particular, it has been reported recently that the upgrade of a wavelength channel to a high spectral efficiency format is constrained by nonlinear cross-talk from the other network traffic [14][15][16], especially if the reach is such that intra-channel nonlinearities degrading the higher bit-rate traffic (e.g. 400 Gb/s) require mitigation by the use of digital back-propagation (DBP) [17][18][19].…”

“…2), but with the node spacing set to the nearest 80km, allowing for uniformly spaced amplifiers. For all the carriers, at all of the nodes, both the polarization states were modulated independently using de-correlated 2 15 and 2 16 pseudo-random bit sequences (PRBS) with different random number seeds, for x-and y-polarization states, respectively. Each PRBS was de-multiplexed separately into two multi-level output symbol streams which were used to modulate an in-phase and a quadrature-phase carrier.…”