Energy efficient hybrid WDM-TDM passive optical networks with access-load difference between ONUs using FBGs, SOA and DWS

The rapid increase in internet services demands high capacity and brings high energy dissipation. For broadband access networks, energy efficient passive optical networks (PONs) are ubiquitously demonstrated to conserve energy. However, high cost components for monitoring, complexity, delays and synchronization issues in active/passive optical network unit (ONU) status are the utmost issues to be addressed. Energy efficient symmetrical Wavelength division multiplexed (WDM) and Time division multiplexed (TDM) hybrid passive optical network using Access-Load Difference between ONUs (ALD) approaches with dynamic wavelength switches has been proposed. Dual capacity providing system is presented where 2 Gbps and 12 Gbps sources are operated according to traffic at ONUs. Total capacity of individual low data rate transmitter are 8 Gbps (2 Gbpsx4) and 48 Gbps (12 Gbpsx4) for each ODN serving 64 ONU. Proposed approach is competent to only use specific transmitter module based on load at ONU and keep rest of the transmitters inactive. Design of ALD DWS is such that there is no service interruption even when any transmitter stops working. Moreover, nonlinear carrier generation eliminate the requirements of lasers for upstream transmission which saves cost as well as energy. It is observed that proposed system save 400% energy below 10 Gbps, 300% between 10-20 Gbps, 200% between 20-30 Gbps, 100% between 30-40 Gbps and 0% for beyond 50 Gbps. Therefore variable transmitters (Bandwidth) are operational in this architecture and provide economical in initial operational expenditure (OPEX).