دانلود رایگان مقاله چه زمانی برنامه نویسی شبکه مبتنی بر تکنیک های چند خانگی پویا مفید است؟

Abstract

Mechanisms that can cope with unreliable wireless channels in an efficient manner are required due to the increasing number of resource constrained devices. Concurrent use of multiple communications technologies can be instrumental towards improving services to mobile devices in heterogeneous networks. In our previous work, we developed an optimization framework to generate channel-aware transmission policies for multi-homed devices under different cost criteria. Our formulation considers network coding as a key technique that simplifies load allocation across multiple channels and provides high resiliency under time-varying channel conditions. This paper seeks to explore the parameter space and identify the operating regions where dynamic coded policies offer most improvement over static ones in terms of energy consumption and channel utilization. We leverage meta-heuristics to find different local optima, while also tracking the intermediate solutions to map operating regions above 3 dB and 5 dB. Our results show a large set of relevant configurations where high resource efficiency can be obtained with the proposed transmission mechanisms.

6. Conclusions

In this paper we sought to identify the operating regions under which dynamic coded policies bring most benefits in terms of resource efficiency. We proposed meta-heuristics to explore the parameter space, not only to find different local optima, but also to map areas whose performance is above a certain level. The results demonstrated that opportunistic assignment of the traffic load over heterogeneous time-varying channels can in fact achieve considerable gains. In particular, dynamic network coding policies allow energy consumption and channel utilization savings over 5 dB with respect to the best static policy in a large number of scenarios. Future work shall focus on scheduling algorithms that can implement the policies through single packet decisions, incorporate unreliable estimates of the channel, and explicit trade-offs between delay, energy, and economic cost. Acknowledgements We thank the anonymous reviewers for their helpful feedback. We would like to thank André Moreira for the discussions along the COHERENT project. This work was partially supported by the project I-City for Future Health NORTE-07-0124-FEDER-000068, by the European Project FP7 - Future Cities FP7-REGPOT-2012-2013- 1, by PT Inovação, by the Green Mobile Cloud project granted by the Danish Council for Independent Research (DFF - 0602-01372B), and by Fundação para a Ciência e a Tecnologia under the project UID/EEA/ 50008/2013 in the scope of R&D Unit 50008, financed by the applicable financial framework (FCT/MEC through national funds and when applicable co-funded by FEDER - PT2020 partnership agreement).