دانلود رایگان مقاله بهبود انرژی ذخیره ویدئو در شبکه نوری هسته آینده

Abstract

Optical networks are expected to cater for the future Internet due to the high speed and capacity that they offer. Caching in the core network has proven to reduce power usage for various video services in current optical networks. This paper investigates whether video caching will still remain power efficient in future optical networks. The study compares the power consumption of caching in a current IP over WDM core network to a future network. The study considers a number of features to exemplify future networks. Future optical networks are considered where: (1) network devices consume less power, (2) network devices have sleep-mode capabilities, (3) IP over WDM implements lightpath bypass, and (4) the demand for video content significantly increases and high definition video dominates. Results show that video caching in future optical networks saves up to 42% of power consumption even when the power consumption of transport reduces. These results suggest that video caching is expected to remain a green option in video services in the future Internet.

Conclusion

This paper has evaluated the benefit of content caching in IP over WDM core networks with respect to current and future networks. It compares power savings due to caching when network devices are provisioned for peak traffic and when the network is equipped with sleep-mode capable hardware. It also evaluates the power consumption under lightpath non-bypass and lightpath bypass. Moreover, it investigates the potential of caching as a power efficient solution if the power consumption of transport significantly decreases. Finally, it evaluates the power consumption of the combined effect of all considered network features as well as daily energy consumption reductions due to caching. The results reveal that sleep-mode capable equipment reduces a substantial amount of power due to traffic adaptation. Even though, caching introduces additional power savings of up to 38% of power consumption with and without sleep-mode capabilities. These savings increase to 42% under variable caching when sleepmode capabilities are implemented. The results also show that when the power consumption of transport decreases, similar caching power savings of up to 42% are achieved, however, the optimum cache sizes that result in minimizing power reduce. This influence is also observed when lightpath bypass is implemented, since remote access for video content is more favorable. The power savings due to caching are up to 46% and 42% under lightpath nunbypass and lightpath bypass, respectively. The similar power saving figure of 42% achieved under different scenarios is due to the constant input traffic used in the evaluation where caching reduces the power consumption of download traffic alone. When combining all network features, caching reduces up to 22% and 43% of power consumption under current and future optical networks, respectively