PROaccess : a passive-components-based reconfigurable WDM-TDM optical access network

The evolution of optical access networks have focused on improving their transmission capacity by increasing transmission bit rate per wavelength and number of wavelengths per fibre. However, the huge aggregated capacity is composed by separate bandwidth pools in which each wavelength channel is an independent pool. As a result, some wavelengths may be congested while others are underutilization. In order to allow the system capacity to be a single bandwidth pool, the wavelength reconfigurability is required in which an user can be relocated to another wavelength if the current wavelength is congested. Adding reconfigurable feature also adds complexity, hence CAPEX and OPEX to the networks. Therefore, networks operators up to now have been reluctant despite of benefits of the flexible bandwidth delivery. In this paper, we propose a cost-effective, reconfigurable optical access network by employing passive network components in the remote node and dual conventional optical transceivers in ONUs. The novel approach allows outside plant totally passive and ONUs without tunable filters and lasers. Despite of using only passive and non-tunable components, it still attains a superior flexibility. The architecture is demonstrated with the bidirectional transmission at 10 Gb/s symmetrically.