WSANs中基于可靠性最大化的報文實時投遞方案

崔立尉++楊申浩

摘 要 無線傳感反應器網絡（WSANs）中現有的報文投遞方案可靠性不足，不適用于數據率互不相同的網絡場景.為此，提出一種基于可靠性最大化的報文實時投遞方案.報文投遞問題被分解為兩個子問題：基于子周期的時隙分配問題和基于時隙的傳輸調度問題.第1個子問題被轉化為一個線性整數規劃問題，并給出一種具有多項式時間復雜度的求解方法.對于第2個子問題，文中證明是否存在最優可行調度取決于求解前一子問題時獲得的時隙分配向量中的元素次序，然后給出一種可行時隙分配方案求解算法.仿真結果表明，本文算法可保證每個設備即使在不同的報告周期內也可實現基本相同的報文投遞率，這一特性對于維持控制系統的穩定性具有重要作用.

關鍵詞 無線傳感反應器網絡；流量；非線性整數規劃；可靠性；時隙；報文投遞率；穩定性

中圖分類號 TP393 文獻標識碼 A 文章編號 10002537（2016）010085010

A RealTime Delivery Scheme of Packet Based on Reliability

Maximization in Wireless SensorActuator Networks

CUI Liwei1，2， YANG Shenhao3*

（1. School of Information Management and Computer Technology， Inner Mongolia Agricultural University， Baotou 014109， China；

2. School of Information Engineering， Inner Mongolia University of Science and Technology， Baotou 014010， China；

3. School of Computer Science and Technology， Tsinghua University， Beijing 100083， China）

Abstract The existing packet delivery schemes have a low reliability in wireless sensoractuator networks （WSANs）. Hence， these schemes are not suitable for networks with heterogeneous traffic rates. To solve this problem， a realtime delivery scheme of packet based on reliability maximization is proposed. The packet delivery problem is decomposed into two subproblems： subperiodbased slot allocation and slotbased transmission scheduling. The former subproblem is formulated as a linear integer programming problem， and we present a solution with polynomialtime complexity. For the latter subproblem， we demonstrate that the existence of a feasible optimal schedule depends on the order of the elements in the slot allocation vector produced by solving the former subproblem， and then an algorithm is designed to compute a feasible slot allocation that sustains a realizable schedule. Simulation results demonstrate that our scheme ensures each device has almost the same packet delivery rate in different report periods， which is important for maintaining the stability of control systems.

Key words wireless sensoractuator networks； traffic； nonlinear integer programming； reliability； slot； packet delivery rate； stability

基于無線傳感反應器網絡[1]（WSANs）的工業自動化技術在降低部署成本和提高系統靈活性方面具有巨大優勢，因此在近些年引起了研究和工業領域的大量關注.為了促進WSANs在工業領域的應用，人們已經提出了3套國際標準[23]：WirelessHART，ISA 100.11a和IEEE 802.15.4e.這些標準均采用基于IEEE 802.15.42006標準且支持2.4 GHz ISM頻段16個信道的低功率無線電技術.然而，采用這些低功率無線電技術的設備非常不可靠，且鏈路質量往往具有時變特性，尤其是惡劣環境下更是如此，比如存在大量噪聲且對象……