智慧終端耗電與頻寬權衡之多天線管理機制

Abstract

隨著無線網路資料傳輸的爆炸性成長，越來越多的智慧終端設備已配備支援 IEEE 802.11n 標準的多天線無線網路介面卡以應付智慧終端上各式各樣的應用，包括一些帶寬密集型應用。 最近研究顯示，802.11n 介面卡隨著天線個數的增加，也帶來相當大的耗電，因此智慧終端設備的多天線能源管理是一項重要的挑戰。 在本文中，我們提出一套多天線的動態管理機制來有效降低多天線的智慧終端設備的資料傳輸耗能。 其關鍵思想是根據進入網絡佇列中的傳輸資料量，動態地調整​​天線配置以達到能源和帶寬之間的權衡。首先，我們建立動態多天線管理最佳化問題的耗電模型，最小化多天線智慧終端設備進行資料傳輸的總能量耗損。第二，我們在離線的環境下提出了一個最佳化動態規劃演算法 ，並於在線的環境下提出一套競爭演算法與競爭比理論分析。實驗結果顯示多天線的動態管理機制與現存 802.11n 於智慧終端設備上的能源節省機制相比可達到百分之五十的能源節省。

Increasingly, mobile devices equipped with 802.11n interfaces are being used for a wide variety of applications including some bandwidth-intensive applications. Recent work has shown that 802.11n interfaces are power-hungry with the increased antennas, so energy management for multi-antenna mobile devices is an important challenge. In this paper, we present a dynamic multi-antenna management mechanism (DAM) to reduce the communication energy consumption of MIMO-based mobile devices. The key idea is to dynamically adjusts antenna configuration according to packet workloads come into the network queue to realize and trade-off between energy savings and bandwidth. First, we model the problem with an objective to minimize the total energy consumption of MIMO-based mobile devices for transmission. Second, we propose an offline optimal dynamic-programming algorithm to solve the fundamental problem and given a competitive online algorithm with theoretical analysis. The results of experiments conducted based on real user traces to evaluate the efficacy of the proposed design show that DAM could achieve 50\% energy saving of an native power saving mechanism supported by commercial 802.11n mobile devices.