Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : Fair greening of broadband access: spectrum management for energy-efficient DSL networks | Tsiaflakis et al. EURASIP Journal on Wireless Communications and Networking 2011 2011 140 EURASIP Journal on . http content 2011 1 140 Wireless Communications and Networking a SpringerOpen Journal RESEARCH Open Access Fair greening of broadband access spectrum management for energy-efficient DSL networks Paschalis Tsiaflakis1 Yung Yi2 Mung Chiang3 and Marc Moonen1 Abstract Dynamic spectrum management DSM is recognized as a promising technology to reduce power consumption in DSL access networks. However the correct formulation of power-aware DSM problem statements requires a proper understanding of greening . reducing power consumption. In this paper we therefore investigate greening and show that it can be decomposed into two dimensions the price of greening and the fairness of greening. We first analyze the price of greening providing theoretical bounds on the power-rate trade-off and identifying the typical trends that can be expected in practice with some particularly promising results. Then we introduce the fairness dimension where we show that fairness becomes crucial when reducing power consumption. We propose four different fair greening policies that can be used to obtain a favorable trade-off between fast fair and green DSL operation. Finally we evaluate and quantify the corresponding trade-offs for realistic DSL access networks. 1. Introduction Digital subscriber line DSL refers to a family of technologies that enable digital broadband Internet access over the local telephone network. It is currently the dominating wireline broadband access technology with a global market share of 65 1 . The main reason for its popularity is its low deployment cost as DSL reuses the twisted pairs of the existing telephone network infrastructure to connect subscribers to the Internet backbone. To cope with the increasing demands of the users endusers as well as service providers and to stay competitive with other broadband access technologies .
