BER-Adaptive RMLSA Algorithm for Wide-Area Flexible Optical Networks

Wide-area optical networks face significant transmission challenges due to the relentless growth of bandwidth demands experienced nowadays. Network operators must consider the relationship between modulation format and maximum reach for each connection request due to the accumulation of physical layer impairments in optical fiber links, to guarantee a minimum quality of service (QoS) and quality of transmission (QoT) to all connection requests. In this work, we present a BER-adaptive solution to solve the routing, modulation format, and spectrum assignment (RMLSA) problem for wide-area elastic optical networks. Our main goal is to maximize successful connection requests in wide-area networks while choosing modulation formats with the highest efficiency possible. Consequently, our technique uses an adaptive bit-error-rate (BER) threshold to achieve communication with the best QoT in the most efficient manner, using the strictest BER value and the modulation format with the smallest bandwidth possible. Additionally, the proposed algorithm relies on 3R regeneration devices to enable long-distances communications if transparent communication cannot be achieved. We assessed our method through simulations for various network conditions, such as the number of regenerators per node, traffic load per user, and BER threshold values. In a scenario without regenerators, the BER-Adaptive algorithm performs similarly to the most relaxed fixed BER threshold studied in blocking probability. However, it ensures a higher QoT to most of the connection requests. The proposed algorithm thrives with the use of regenerators, showing the best performance among the studied solutions, enabling long-distance communications with a high QoT and low blocking probability

Geographies of development II: cash transfers and the reinvention of development for the poor.

Since the mid-1990s, a number of governments in the global South have instituted programmes which provide regular cash grants to poor people. The results of cash transfer programmes have been impressed those searching for ways to improve welfare: the depth of poverty has been reduced, more children are being educated and vaccinated, and the poor are more likely to get jobs and start enterprises. Advocates of social democracy are hopeful that this heralds the possibility of comprehensive social protection. Experiments in welfare in the global South do not, however, inevitably signal an epochal shift to a postneoliberal era. They form part of an increasingly heterodox approach which combines an enduring emphasis on liberalised economic growth with bolder biopolitical interventions for the poor