CN107949042B - 能量采集型无线传感网络的低存储自适应传输调度方法 - Google Patents

能量采集型无线传感网络的低存储自适应传输调度方法 Download PDF

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CN107949042B
CN107949042B CN201711088190.7A CN201711088190A CN107949042B CN 107949042 B CN107949042 B CN 107949042B CN 201711088190 A CN201711088190 A CN 201711088190A CN 107949042 B CN107949042 B CN 107949042B
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CN107949042A (zh
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黄亮
冯旭
钱丽萍
吴远
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Hangzhou Qizhi Energy Technology Co ltd
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Zhejiang University of Technology ZJUT
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/02Power saving arrangements
    • H04W52/0209Power saving arrangements in terminal devices
    • H04W52/0212Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave
    • H04W52/0219Power saving arrangements in terminal devices managed by the network, e.g. network or access point is master and terminal is slave where the power saving management affects multiple terminals
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/30TPC using constraints in the total amount of available transmission power
    • H04W52/36TPC using constraints in the total amount of available transmission power with a discrete range or set of values, e.g. step size, ramping or offsets
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W84/00Network topologies
    • H04W84/18Self-organising networks, e.g. ad-hoc networks or sensor networks
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02DCLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
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Abstract

一种适用于能量采集型无线传感网络的低存储自适应传输调度方法,包括以下步骤:1)在由一对发射机和接收机组成的时隙能量收集通信系统中,根据数据和能量定义出系统状态;2)为传输调度策略解出能量采集传输系统的期望收益;3)计算系统状态为(1,j)的期望收益差Δ(1,j);4)计算系统状态为(i,1)的期望收益差Δ(i,1);5)对于每一个收益阈值vth(i,j)计算相应的期望收益差
Figure DDA0001460567480000011
Figure DDA0001460567480000012
得到最佳阈值
Figure DDA0001460567480000013
本发明通过安排数据传输和管理已获得的能量最大化了长期平均传输收益,保证了无线传感器网络中的传输可靠性。

Description

能量采集型无线传感网络的低存储自适应传输调度方法
技术领域
本发明属于通信领域,方法尤其是涉及具有能量采集的通信系统以及用于能量采集型无线传感网络的低存储自适应传输调度方法。
背景技术
当前,无线传感器网络已经广泛部署用于物联网,包括环境控制,对象跟踪,健康监控等。然而,这些普遍的无电缆传感器节点通常受到由于感测和无线通信的有限能量的约束。为此,当前已经提出能量收集技术,作为应对无线传感器网络中的能量消耗的解决方案。具体来说,传感器节点由环境能量供电,例如太阳能,风能,热电功率和射频功率。由于数据到达和能量获得的随机性,为了保证无线传感器网络中的传输可靠性,系统管理能量供应是很有必要的。
发明内容
为了克服能量采集型无线传感网络传输调度方式存在的能量到达的间歇性的不足,为了保证无线传感器网络中的传输可靠性,本发明提供了一种适用于能量采集型无线传感网络的低存储自适应传输调度方法,最大化长期平均传输收益,系统管理能量供应,每个传感器节点只需要有限的容量去存储一些最佳阈值来实现能量管理。
本发明解决其技术问题所采取的技术方案是:
一种适用于能量采集型无线传感网络的低存自适应储传输调度方法,所述方法包括以下步骤:
1)在由一对发射机和接收机组成的时隙能量收集通信系统中。将时间间隔[t,t+1)表示为时隙t,其中t属于正整数;假设发射机在时隙t具有的数据包个数为Dt,具有的能量包个数为Et;在每个时隙中,允许发射机通过精确消耗一个能量包来发送最多一个数据包。假设数据缓冲器大小和能量存储容量分别为D和E;能量收集系统状态(Dt,Et)的稳态空间被定义为:
{(i+1,0),(1,1),(1,j+1):i=1,2,...,D,j=1,2,...,E} (1)
其中,式中各参数定义如下:
D:数据缓冲器大小;
E:能量存储容量;
2)为传输调度策略解出能量采集传输系统的期望收益,期望收益G为:
Figure GDA0002690017350000021
式中:
Figure GDA0002690017350000022
Figure GDA0002690017350000023
Figure GDA0002690017350000024
Figure GDA0002690017350000025
Figure GDA0002690017350000026
其中,各参数定义如下:
p(i,j):发送器内有i个数据包和j个能量包的稳态概率;
Figure GDA0002690017350000027
系统状态为(i,j)时,数据包传输平均收益;
Figure GDA0002690017350000028
系统状态为(i,j)时,数据包的收益值大于或等于阈值的概率;
λd:数据包到达概率;
λe:能量包到达概率;
D:数据缓冲器大小;
E:能量存储容量;
3)如果将收益阈值vth(1,j)更改为v′th(1,j),并保持剩下的收益阈值不变,就得到了新的期望收益G′,同时当收益阈值v′th(1,j)大于vth(1,j)时,期望收益差Δ(1,j)大于0,当收益阈值v′th(1,j)小于vth(1,j)时,期望收益差Δ(1,j)小于0,期望收益差Δ(1,j)为:
Figure GDA0002690017350000031
式中:
Figure GDA0002690017350000032
4)与步骤3)类似,对于剩下的系统状态(i,1),计算出相应的期望收益差Δ(i,1)
Figure GDA0002690017350000033
式中:
Figure GDA0002690017350000034
5)假设每一个收益阈值只能变成它所相邻的收益值,在多次迭代调整后,期望收益将会收敛于最佳,将
Figure GDA0002690017350000035
表示为当收益阈值改成其在收益值集合中加一位置的收益值时的期望收益差,相应的,将
Figure GDA0002690017350000036
表示为当收益阈值改成其在收益值集合中减一位置的收益值时的期望收益差;对于每一个收益阈值vth(i,j)计算相应的
Figure GDA0002690017350000037
Figure GDA0002690017350000038
如果
Figure GDA0002690017350000039
大于0或者
Figure GDA00026900173500000310
小于0,通过分别增加或减小收益阈值vth(i,j)提升期望收益;实现过程为:
步骤5.1:为所有的系统状态(i,1)和(1,j)计算出相应的期望收益差
Figure GDA0002690017350000041
Figure GDA0002690017350000042
步骤5.2:对于每一个系统状态(i,j),当
Figure GDA0002690017350000043
大于0时,增加收益阈值vth(i,j);当
Figure GDA0002690017350000044
小于0时,减小收益阈值vth(i,j);
步骤5.3:得出新的收益阈值vth(i,j)后,对所有的系统状态(i,1)和(1,j)计算出相应的新的期望收益差
Figure GDA0002690017350000045
Figure GDA0002690017350000046
再次回到步骤5.2重新调整,在多次迭代后,得出最佳阈值
Figure GDA0002690017350000047
本发明的技术构思为:首先,由于数据到达和能量获得的随机性,在每个瞬时间有不同的数据和能量存储状态,为了最大化长期平均传输收益,基于这些不同的系统状态,提出了一个阈值策略来安排数据传输和管理已获得的能量,通过分别地考虑数据存储状态和能量存储状态,对于每一个收益阈值vth(i,j)计算出相应的期望收益差
Figure GDA0002690017350000048
Figure GDA0002690017350000049
进而根据期望收益差
Figure GDA00026900173500000410
Figure GDA00026900173500000411
来调整收益阈值vth(i,j),在多次迭代后,得出最佳阈值
Figure GDA00026900173500000412
最终提升整个能量采集传输系统的期望收益。
本发明的有益效果主要表现在:基于阈值的低存储自适应传输调度策略通过安排数据传输和管理已获得的能量计算出最佳阈值,每个传感器节点只需要有限的容量去存储一些最佳阈值来实现能量管理,最大化了长期平均传输收益,保证了无线传感器网络中的传输可靠性。
附图说明
图1是系统状态示意图。
图2是计算最佳阈值的方法流程图。
具体实施方式
下面结合附图对本发明作进一步详细描述。
参照图1和图2,一种能量采集型无线传感网络的自适应低存储传输调度方法,实行该方法能最大化长期平均传输收益,保证无线传感器网络中的传输可靠性。本发明基于不同的系统状态(如图1所示),提出了一个阈值策略来安排数据传输和管理已获得的能量,通过分别地考虑数据存储状态和能量存储状态,对于每一个收益阈值vth(i,j)计算出相应的期望收益差
Figure GDA0002690017350000051
Figure GDA0002690017350000052
进而根据期望收益差
Figure GDA0002690017350000053
Figure GDA0002690017350000054
来调整收益阈值vth(i,j),在多次迭代后,得出最佳阈值
Figure GDA0002690017350000055
最终提升整个能量采集传输系统的期望收益,所述方法包括以下步骤(如图2所示):
1)在由一对发射机和接收机组成的时隙能量收集通信系统中。将时间间隔[t,t+1)表示为时隙t,其中t属于正整数。假设发射机在时隙t具有的数据包个数为Dt,具有的能量包个数为Et。在每个时隙,允许发射机通过精确消耗一个能量包来发送最多一个数据包。假设数据缓冲器大小和能量存储容量分别为D和E。能量收集系统状态(Dt,Et)的稳态空间被定义为:
{(i+1,0),(1,1),(1,j+1):i=1,2,...,D,j=1,2,...,E} (1)
其中,式中各参数定义如下:
D:数据缓冲器大小;
E:能量存储容量;
2)为传输调度策略解决能量采集传输系统的期望收益,期望收益G为:
Figure GDA0002690017350000056
式中:
Figure GDA0002690017350000057
Figure GDA0002690017350000058
Figure GDA0002690017350000061
Figure GDA0002690017350000062
Figure GDA0002690017350000063
其中,各参数定义如下:
p(i,j):发送器内有i个数据包和j个能量包的稳态概率;
Figure GDA0002690017350000064
系统状态为(i,j)时,数据包传输平均收益;
Figure GDA0002690017350000065
系统状态为(i,j)时,数据包的收益值大于或等于阈值的概率;
λd:数据包到达概率;
λe:能量包到达概率;
D:数据缓冲器大小;
E:能量存储容量;
3)如果将收益阈值vth(1,j)更改为v′th(1,j),并保持剩下的收益阈值不变,就得到了新的期望收益G′。当收益阈值v′th(1,j)大于vth(1,j)时,期望收益差Δ(1,j)大于0,当收益阈值v′th(1,j)小于vth(1,j)时,期望收益差Δ(1,j)小于0,期望收益差Δ(i,j)为:
Figure GDA0002690017350000066
式中:
Figure GDA0002690017350000067
4)与步骤3)类似,对于剩下的系统状态(i,1),计算出相应的期望收益差Δ(i,1)
Figure GDA0002690017350000068
式中:
Figure GDA0002690017350000071
5)通过上述的方法分析,提出了一个实现方案并假设每一个收益阈值只能变成它所相邻的收益值。在多次迭代调整后,期望收益将会收敛于最佳,将
Figure GDA0002690017350000072
表示为当收益阈值改成其在收益值集合中加一位置的收益值,相应的,将
Figure GDA0002690017350000073
表示为当收益阈值改成其在收益值集合中减一位置的收益值;对于每一个收益阈值vth(i,j)计算相应的
Figure GDA0002690017350000074
Figure GDA0002690017350000075
如果
Figure GDA0002690017350000076
大于0或者
Figure GDA0002690017350000077
小于0,通过分别增加或减小收益阈值vth(i,j)提升期望收益;实现过程为:
步骤5.1:为所有的系统状态(i,1)和(1,j)计算出相应的期望收益差
Figure GDA0002690017350000078
Figure GDA0002690017350000079
步骤5.2:对于每一个系统状态(i,j),当
Figure GDA00026900173500000710
大于0时,增加收益阈值vth(i,j);当
Figure GDA00026900173500000711
小于0时,减小收益阈值vth(i,j);
步骤5.3:得出新的收益阈值vth(i,j)后,对所有的系统状态(i,1)和(1,j)计算出相应的新的期望收益差
Figure GDA00026900173500000712
Figure GDA00026900173500000713
再次回到步骤5.2重新调整,在多次迭代后,得出最佳阈值
Figure GDA00026900173500000714

Claims (1)

1.一种能量采集型无线传感网络的低存储自适应传输调度方法,其特征在于:所述方法包括以下步骤:
1)在由一对发射机和接收机组成的时隙能量收集通信系统中,将时间间隔[t,t+1)表示为时隙t,其中t属于正整数;假设发射机在时隙t具有的数据包个数为Dt,具有的能量包个数为Et;在每个时隙,允许发射机通过精确消耗一个能量包来发送最多一个数据包;假设数据缓冲器大小和能量存储容量分别为D和E;能量收集系统状态(Dt,Et)的稳态空间被定义为:
{(i+1,0),(1,1),(1,j+1):i=1,2,…,D,j=1,2,...,E} (1)
其中,式中各参数定义如下:
D:数据缓冲器大小;
E:能量存储容量;
2)为传输调度策略解出能量采集传输系统的期望收益,期望收益G为:
Figure FDA0002690348100000011
式中:
Figure FDA0002690348100000012
Figure FDA0002690348100000013
Figure FDA0002690348100000014
Figure FDA0002690348100000015
Figure FDA0002690348100000016
其中,各参数定义如下:
p(i,j):发送器内有i个数据包和j个能量包的稳态概率;
Figure FDA0002690348100000021
系统状态为(i,j)时,数据包传输平均收益;
Figure FDA0002690348100000022
系统状态为(i,j)时,数据包的收益值大于或等于阈值的概率;
λd:数据包到达概率;
λe:能量包到达概率;
D:数据缓冲器大小;
E:能量存储容量;
3)如果将收益阈值vth(1,j)更改为v′th(1,j),并保持剩下的收益阈值不变,就得到了新的期望收益G′;当收益阈值v′th(1,j)大于vth(1,j)时,期望收益差Δ(1,j)大于0,当收益阈值v′th(1,j)小于vth(1,j)时,期望收益差Δ(1,j)小于0,期望收益差Δ(1,j)为:
Figure FDA0002690348100000023
式中:
Figure FDA0002690348100000024
4)对于剩下的系统状态(i,1),计算出相应的期望收益差Δ(i,1)
Figure FDA0002690348100000025
式中:
Figure FDA0002690348100000026
5)假设每一个收益阈值只能变成它所相邻的收益值,在多次迭代调整后,期望收益将会收敛于最佳,将
Figure FDA0002690348100000027
表示为当收益阈值改成其在收益值集合中加一位置的收益值时的期望收益差,相应的,将
Figure FDA0002690348100000028
表示为当收益阈值改成其在收益值集合中减一位置的收益值时的期望收益差;对于每一个收益阈值vth(i,j)计算相应的
Figure FDA0002690348100000031
Figure FDA0002690348100000032
如果
Figure FDA0002690348100000033
大于0或者
Figure FDA0002690348100000034
小于0,通过分别增加或减小收益阈值vth(i,j)提升期望收益,实现过程为:
步骤5.1:为所有的系统状态(i,1)和(1,j)计算出相应的期望收益差
Figure FDA0002690348100000035
Figure FDA0002690348100000036
步骤5.2:对于每一个系统状态(i,j),当
Figure FDA0002690348100000037
大于0时,增加收益阈值vth(i,j);当
Figure FDA0002690348100000038
小于0时,减小收益阈值vth(i,j);
步骤5.3:得出新的收益阈值vth(i,j)后,对所有的系统状态(i,1)和(1,j)计算出相应的新的期望收益差
Figure FDA0002690348100000039
Figure FDA00026903481000000310
再次回到步骤5.2重新调整,在多次迭代后,得出最佳阈值
Figure FDA00026903481000000311
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