Cross-layer Scheduling with Feedback for QoS Support

AbstractNext-Generation Networks (NGNs) will support Quality of Service (QoS) over a mixed wired and wireless IP-based infrastructure. A relative model of service differentiation in Differentiated Services architecture is a scalable solution for delivering multimedia traffic. However, considering the dynamic nature of radio channels typically, it is difficult to achieve a given service provisioning working at the IP and lower layers separately as in the classical approach, without a run-time adaptation of the system towards the target quality. This work describes an IP cross-layer scheduler able to support a Proportional Differentiation Model (PDM) for delay guarantees with content-awareness, also over wireless. The key idea is to leverage feedbacks from the lower layers about the actual delays experienced by packets in order to tune at run-time the priority of the IP service classes in a closed-loop control with the objective of supporting a PDM at the network node on the whole, considering the cumulative latency in crossing the first three layers of the protocol stack, as relevant for the end-user. A simulation analysis demonstrates the prominent improvements in reliability and robustness of the proposal in the case of time-variant performance of the MAC and PHY layers with respect to the classical non-cross-layer approach and the open- loop control. Furthermore, considerations on the required functionality and likely deployment scenarios highlight the scalability and backward compatibility of the designed solution in supporting the concept of network transparency for the delivering of critical applications, as of the e-health domain

Optimisation of multimedia over wireless IP links via X-layer design: an end-to-end transmission chain simulator

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Elaboración de una bebida nutricional en polvo a partir de la almendra choibá (Dipteryx oleifera Benth)

A powdered nutritional drink was elaborated from choibá almond (Dipteryx oleifera Benth), "Cariaco" corn flour, soy protein and powdered milk with minimum 16% proteins. Three formulations with choibá almond flour between 43 and 62% were tested. The sensory evaluation was carried out by a trained panel through the Hedonic scale. A formulation was the most accepted with 62% choibá almond flour, 21% "Cariaco" corn flour, 7% soy protein and 10% whole powdered milk. Choibá almonds are a high nutritional alternative far powdered drink.Se elaboró una bebida nutricional en polvo a partir de la almendra choibá (Dipteryx oleifera Benth), harina de maíz "Cariaco", proteína de soya y leche en polvo con un mínimo de 16% de proteínas. Se establecieron tres formulaciones que presentaron un contenido de harina de almendra choibá entre 43 y 62%. La evaluación sensorial se realizó mediante un panel no entrenado a través de la escala Hedónica. La formulación con mayor aceptación fue la formulación A constituida por 62 % de harina de almendra choibá, 21% de harina de maíz "Cariaco", 7% de proteína de soya y 10% de leche en polvo entera. Se concluye que las almendras de choibá son una alternativa nutricional para la elaboración de bebidas altamente proteicas