CN103269503B

CN103269503B - The low conflict speed of a kind of wireless nano sensor network distinguishes multiple access method

Info

Publication number: CN103269503B
Application number: CN201310187407.5A
Authority: CN
Inventors: 池凯凯; 李燕君; 田贤忠; 潘建; 朱艺华
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Nanjing Jisen Technology Development Co ltd
Priority date: 2013-05-17
Filing date: 2013-05-17
Publication date: 2015-11-25
Anticipated expiration: 2033-05-17
Also published as: CN103269503A

Abstract

The low conflict speed of a kind of wireless nano sensor network distinguishes multiple access method, is completed the access control of access node by the simple computation in the low complex degree interaction step of access node and via node and via node.By sending an access request control bag, access node notifies that via node has new data flow to need relaying, and wait for that via node informs the character rate that will use; Via node controls bag once receive access request, calculates the character rate of minimum collision probability, and notifies that access node uses this character rate to send packet by replying a control bag.Wherein, via node is used for the formula (1) of the character rate calculating minimum collision probability is core of the present invention.The present invention is highly suitable for the lower nano-sensor node of disposal ability, can reduce the probability that wireless nano sensor network interior joint sends conflict.

Description

A low collision rate differentiated multiple access method for wireless nanosensor networks

技术领域technical field

本发明涉及一种无线通信中的速率区分多址接入方法，该方法适用于无线纳米传感器网络。The invention relates to a rate-differentiated multiple access method in wireless communication, which is suitable for wireless nanometer sensor networks.

技术背景technical background

随着纳米技术的快速发展，制造出纳米级大小的传感器即纳米传感器已经成为可能。将纳米传感器通过无线通信技术进行相互连接所组成的网络则称为无线纳米传感器网络。无线纳米传感器网络在环境、医疗、工业、军事等领域有着非常广泛的应用前景。由于纳米传感器网络中的纳米传感器节点仅仅具有约几百纳米的大小，其纳米处理器的处理能力非常有限，因此设计复杂度极低的通信协议是无线纳米传感器网络有待研究的关键问题之一。With the rapid development of nanotechnology, it has become possible to manufacture sensors with nanoscale size, that is, nanosensors. The network formed by interconnecting nanosensors through wireless communication technology is called wireless nanosensor network. Wireless nanosensor network has a very broad application prospect in the fields of environment, medical treatment, industry, military and so on. Since the nanosensor nodes in the nanosensor network are only about a few hundred nanometers in size and the processing power of the nanoprocessor is very limited, designing a communication protocol with extremely low complexity is one of the key issues to be studied in the wireless nanosensor network.

无线纳米传感器网络通信协议的各个子协议设计都需要考虑到计算复杂度问题，包括物理层调制模式的设计和数据链路层的多址接入方法的设计。关于物理层调制模式的设计，由于键控开关调制即OOK调制具有较低的复杂度，是无线纳米传感器较有应用前景的调制方式之一。OOK调制方式是仅仅在发送“1”比特时发送一个脉冲信号，而在发送“0”比特时保持安静即天线上不发送任何电压信号。而关于数据链路层的多址接入方法的设计，目前为止，有很多文献和专利研究设计了适用于不同无线网络的多址接入方法，比如适用于无线局域网的IEEE802.11MAC协议等。但是这些方法都是针对已有网络的宏观节点来设计，由于这些宏观节点具有相对较高的计算处理能力，这些方法具有相对高的复杂性，比如无线局域网的多址接入方法是基于复杂的基于退避算法的载波监听多路访问机制，而采用CDMA技术的蜂窝网则通过生成复杂的相互正交的扩频码来实现多址接入。但这些高复杂度的多址接入方法都不适用处理能力非常有限的纳米传感器节点。The design of each sub-protocol of the wireless nanosensor network communication protocol needs to consider the computational complexity, including the design of the modulation mode of the physical layer and the design of the multiple access method of the data link layer. As for the design of the modulation mode of the physical layer, the OOK modulation is one of the more promising modulation methods for wireless nanosensors due to its low complexity. The OOK modulation method is to send a pulse signal only when sending a "1" bit, and keep quiet when sending a "0" bit, that is, no voltage signal is sent on the antenna. As for the design of the multiple access method of the data link layer, so far, there are many literatures and patents that have designed multiple access methods suitable for different wireless networks, such as the IEEE802.11MAC protocol suitable for wireless local area networks. However, these methods are designed for the macro-nodes of the existing network. Because these macro-nodes have relatively high computing and processing capabilities, these methods have relatively high complexity. For example, the multiple access method of wireless local area network is based on complex The carrier sense multiple access mechanism based on the back-off algorithm, while the cellular network using CDMA technology realizes multiple access by generating complex mutually orthogonal spread spectrum codes. However, none of these high-complexity multiple-access methods are suitable for nanosensor nodes with very limited processing capabilities.

对于采用OOK调制的无线纳米传感器网络，通过给不同纳米节点设置不同的符号速率来达到多址接入是一种低复杂度、低接入冲突概率的非常有应用前景的多址接入方法。对于采用符号速率r的纳米节点，r为正整数，以r×T_S为周期来发送信息，其中T_S是物理层一个调制符号发送消耗时间。每个周期内只在周期一开始的T_S时间内发送一个调制符号，而后续的(r-1)T_S时长内不发送任何无线信号。采用该多址接入方法，对于两个接入节点所发送的无线电信号，只有在同一时刻恰好都发送了一个调制符号才会发生冲突。通过合理的设置各接入节点的符号速率，可以将冲突概率降到比较低的水平。For wireless nanosensor networks using OOK modulation, setting different symbol rates for different nanonodes to achieve multiple access is a very promising multiple access method with low complexity and low access collision probability. For a nanonode using a symbol rate r, where r is a positive integer, information is sent at a period of r×T _S , where T _S is the time consumed for sending one modulation symbol at the physical layer. In each cycle, only one modulation symbol is sent within the T _S time at the beginning of the cycle, and no wireless signal is sent within the subsequent (r-1) T _S time. With this multiple access method, the radio signals transmitted by two access nodes collide only if exactly one modulation symbol is transmitted at the same time. By properly setting the symbol rate of each access node, the collision probability can be reduced to a relatively low level.

目前为止，已有少量文献研究了该适用于无线纳米传感器网络的速率区分多址接入方法。比如固定速率法、随机速率法等等（参加《PHLAME-APhysicalLayerAwareMACprotocolforElectromagneticnanonetworksintheTerahertzBand》，刊于NanoCommunicationNetworks,2012）。So far, there have been a few literatures that have studied the rate-differentiated multiple access method for wireless nanosensor networks. Such as fixed rate method, random rate method, etc. (Participate in "PHLAME-APhysicalLayerAwareMAC protocol for Electromagnetic nanonetworks in the Terahertz Band", published in NanoCommunicationNetworks, 2012).

发明内容Contents of the invention

针对现有无线多址接入方法因高复杂性而无法应用于具有较低处理能力的无线纳米传感器网络，本发明提出一种低复杂度、低冲突概率的速率区分多址接入方法。当一个无线纳米传感器节点即中继节点需要为一个邻居节点中继来自该邻居节点的新的数据流时，该中继节点通过为该邻居寻找出一个最优的符号速率来降低该邻居节点的发送信号被其它邻居正在发送的信号干扰的概率。Aiming at the fact that the existing wireless multiple access method cannot be applied to the wireless nanometer sensor network with low processing capacity due to its high complexity, the present invention proposes a rate-differentiated multiple access method with low complexity and low collision probability. When a wireless nanosensor node, that is, a relay node, needs to relay a new data stream from the neighbor node for a neighbor node, the relay node reduces the neighbor node's speed by finding an optimal symbol rate for the neighbor node. The probability that a transmitted signal will be interfered with by other neighbors that are transmitting.

为实现上述技术任务，本发明采取如下的技术解决方案：For realizing above-mentioned technical task, the present invention takes following technical solution:

一种无线纳米传感器网络低冲突速率区分多址接入方法,它由“接入节点操作步骤”和“中继节点操作步骤”两部分组成。其中，所述的“接入节点操作步骤”包含如下具体步骤：A low-conflict-rate differentiated multiple access method for a wireless nanometer sensor network, which consists of two parts: "access node operation steps" and "relay node operation steps". Wherein, the "access node operation steps" include the following specific steps:

步骤一：给中继节点发送一个接入请求控制包来通知中继节点本节点有数据流要发往中继节点。Step 1: Send an access request control packet to the relay node to notify the relay node that the node has data flow to be sent to the relay node.

步骤二：接收来自中继节点的回复控制包，然后从该包中读出中继节点所指定的符号速率r_opt，r_opt为一个正整数。Step 2: Receive a reply control packet from the relay node, and then read out the symbol rate r _opt specified by the relay node from the packet, where r _opt is a positive integer.

步骤三：以r_opt×T_S为周期来发送数据包，其中T_S是物理层发送一个调制符号所消耗的时间。每个周期内只在周期一开始的T_S时间内发送一个调制符号，而后续的(r_opt-1)T_S时长内不发送任何无线信号，即保持无线电安静。Step 3: Send a data packet with a period of r _opt ×T _S , where T _S is the time consumed by the physical layer to send a modulation symbol. In each cycle, only one modulation symbol is sent during the T _S time at the beginning of the cycle, and no wireless signal is sent during the subsequent (r _opt -1) T _S time, that is, the radio is kept quiet.

所述的“中继节点操作步骤”包含如下具体步骤：The "relay node operation steps" include the following specific steps:

步骤一：接收接入节点所发送的接入请求控制包。Step 1: Receive the access request control packet sent by the access node.

步骤二：如果接入节点发起的数据流是本中继节点要中继的唯一一个数据流，则设置接入节点的符号速率r_opt为区间[r_min,r_max]中的最大素数，并跳到步骤七；否则，继续执行步骤三。其中，r_min和r_max分别是根据网络时延要求等方面而预先设置好的符号速率允许最小取值和允许最大取值。Step 2: If the data flow initiated by the access node is the only data flow to be relayed by the relay node, set the symbol rate r _opt of the access node to the largest prime number in the interval [r _min , r _max ], and Skip to step seven; otherwise, continue to step three. Among them, r _min and r _max are respectively the allowable minimum value and the allowable maximum value of the symbol rate set in advance according to network delay requirements and other aspects.

步骤三：取r=r_min并设置冲突概率参数Min_P=1，记r_opt=r。Step 3: Take r=r _min and set the conflict probability parameter Min_P=1, record r _opt =r.

步骤四：按式（1）计算接入节点被冲突的概率P(r)。Step 4: Calculate the probability P(r) that the access node is collided according to formula (1).

$P P ((r r)) &equiv; &equiv; P P (({A A}_{11,, n no} \cup \cup {A A}_{22,, n no} \cup \cup . . . . . . \cup \cup {A A}_{n no - - 11,, n no}))$

$= = {Σ Σ}_{i i = = 11}^{n no - - 11} P P (({A A}_{i i,, n no})) - - \underset{11 \leq \leq i i < < j j \leq \leq n no - - 11}{Σ Σ} P P (({A A}_{i i,, n no} \cap \cap {A A}_{j j,, n no})) + + \underset{11 \leq \leq i i < < j j < < k k \leq \leq n no - - 11}{Σ Σ} P P (({A A}_{i i,, n no} \cap \cap {A A}_{j j,, n no} \cap \cap {A A}_{k k,, n no})) - -$

$. . . . . . + + {((- - 11))}^{n no - - 22} P P (({A A}_{11,, n no} \cap \cap {A A}_{22,, n no} \cap \cap . . . . . . \cap \cap {A A}_{n no - - 11,, n no}))$

$= = {Σ Σ}_{i i = = 11}^{n no - - 11} \frac{11}{LCM LCM (({r r}_{i i},, {r r}_{n no}))} - - \underset{11 \leq \leq i i < < j j \leq \leq n no - - 11}{Σ Σ} \frac{11}{LCM LCM (({r r}_{i i},, {r r}_{j j},, {r r}_{n no}))} + + \underset{11 \leq \leq i i < < j j < < k k \leq \leq n no - - 11}{Σ Σ} \frac{11}{LCM LCM (({r r}_{i i},, {r r}_{j j},, {r r}_{k k},, {r r}_{n no}))} - -$

$. . . . . . + + {((- - 11))}^{n no - - 22} \frac{11}{LCM LCM (({r r}_{11},, {r r}_{22},, . . . . . .,, {r r}_{n no}))} - - - - - - ((11))$

其中，n表示当前接入节点发起的数据流的序号，也就是说，中继节点当前已经在为n-1个其他接入节点提供中继服务；A_i,n表示已有的第i个数据流与接入数据流发生符号发送冲突该事件；事件之间的操作符号∪表示事件之间的或关系；事件之间的操作符号∩表示事件之间的且关系；P()表示括号内的事件发生概率；表示整数的最小公倍数。Among them, n represents the serial number of the data flow initiated by the current access node, that is to say, the relay node is currently providing relay services for n-1 other access nodes; A _i,n represents the existing i-th The event of a symbol transmission conflict between the data stream and the access data stream; the operation symbol ∪ between events indicates the OR relationship between events; the operation symbol ∩ between events indicates the AND relationship between events; P() indicates the relationship between events probability of occurrence of the event; Represents an integer least common multiple of .

步骤五：如果P(r)<Min_P，则取Min_P＝P(r)，并记r_opt＝r。Step 5: If P(r)<Min_P, take Min_P=P(r), and record r _opt =r.

步骤六：r=r+1。如果r≤r_max,转入步骤四。Step 6: r=r+1. If r≤r _max , go to step 4.

步骤七：在回复控制包中设置接入节点的符号速率为r_opt，然后向接入节点发送该回复控制包。Step 7: Set the symbol rate of the access node to r _opt in the reply control packet, and then send the reply control packet to the access node.

步骤八：等待接收发自接入节点的数据包。Step 8: Waiting to receive a data packet sent from the access node.

本发明的技术特点及效果：Technical characteristics and effects of the present invention:

1）本发明具有较低的实现复杂度，在接入节点端只需发送一个控制包和接收一个控制包，在中继节点端除了接收一个控制包和发送一个控制包外，只需计算式子（1）。由于无线纳米传感器网络中的纳米节点没有能力同时为很多数据流提供中继服务，即n值很小，因此式子（1）的计算复杂度较低。1) The present invention has low implementation complexity, only one control packet needs to be sent and received at the access node side, and at the relay node side, in addition to receiving one control packet and sending one control packet, only the calculation formula child (1). Since the nanonodes in the wireless nanosensor network do not have the ability to provide relay services for many data streams at the same time, that is, the value of n is small, so the computational complexity of formula (1) is low.

2）本发明基于最优化理论来最小化当前接入节点所发送的信号被已有接入节点所发送的信号冲突的概率，从而可以降低中继节点上数据包接收出错的概率。2) Based on the optimization theory, the present invention minimizes the probability that the signal sent by the current access node is collided with the signal sent by the existing access node, thereby reducing the probability of error in receiving data packets on the relay node.

附图说明Description of drawings

图1是本发明的多址接入方法的执行过程。Fig. 1 is the execution process of the multiple access method of the present invention.

图2是接入节点之间的发送信号发生冲突的示意图。Fig. 2 is a schematic diagram of a collision of transmission signals between access nodes.

具体实施方式Detailed ways

下面结合附图对本发明做进一步说明。The present invention will be further described below in conjunction with the accompanying drawings.

我们以图1所示的多址接入方法的执行过程来说明本发明的具体实施方式。当有一个纳米节点需要某一个通过路由协议所选取出来的邻居节点来中继数据流时，采用本发明的速率区分多址接入方法来接入到中继节点。该方法由“接入节点操作步骤”和“中继节点操作步骤”构成。We use the execution process of the multiple access method shown in FIG. 1 to illustrate the specific implementation of the present invention. When a nano-node needs a certain neighbor node selected through a routing protocol to relay data flow, the rate-differentiated multiple access method of the present invention is used to access the relay node. The method consists of "access node operating steps" and "relay node operating steps".

如图1所示，其中，所述的“接入节点操作步骤”包含以下具体步骤：As shown in Figure 1, wherein the "access node operation steps" include the following specific steps:

步骤二：等待中继节点发送回复控制包，一但中继节点发送该控制包则将其接收，然后从该包中读出中继节点所指定的符号速率r_opt。Step 2: Waiting for the relay node to send a reply control packet, once the relay node sends the control packet, it is received, and then the symbol rate r _opt specified by the relay node is read out from the packet.

步骤三：以r_opt×T_S为周期来发送数据包，其中T_S是物理层发送一个调制符号所消耗的时间。每个周期内只在周期一开始的T_S时间内发送一个调制符号，比特“1”调制成一个脉冲信号，比特“0”则调制成无信号，即不发送无线信号，而后续的(r_opt-1)T_S时长内不发送任何无线信号，即保持无线电安静。Step 3: Send a data packet with a period of r _opt ×T _S , where T _S is the time consumed by the physical layer to send a modulation symbol. In each cycle, only one modulation symbol is sent within the T _S time at the beginning of the cycle, the bit "1" is modulated into a pulse signal, and the bit "0" is modulated into no signal, that is, no wireless signal is sent, and the subsequent (r _opt -1) Do not send any wireless signal within T _S duration, that is, keep the radio quiet.

当接入节点和中继节点完成上述操作步骤后，接入节点在其步骤二中得知中继节点为其安排的符号速率r_opt，并以此符号速率开始往中继节点发送数据包，直到完成该数据流的所有数据包发送为止。After the access node and the relay node complete the above operation steps, the access node learns the symbol rate r _opt arranged by the relay node in its step 2, and starts to send data packets to the relay node at this symbol rate, Until all packets for that flow have been sent.

Claims

1. the low conflict speed of wireless nano sensor network distinguishes a multiple access method, it is characterized in that: it is made up of " access node operating procedure " and " relay node operation step " two parts; Wherein, described " access node operating procedure " comprises following concrete steps:

Step one: send an access request to via node and control bag to notify that this node of via node has data flow to mail to via node,

Step 2: the reply received from via node controls bag, then replys from described the symbol speed r controlling to read bag specified by via node _opt, r _optbe a positive integer,

Step 3: with r _opt× T _sfor the cycle sends packet, wherein T _sit is the time that physical layer sends a modulation symbol and consumes, only at cycle T at the beginning in each cycle _sa modulation symbol is sent in time, and follow-up (r _opt-1) T _sdo not send any wireless signal in duration, namely keep radio quiet;

Described " relay node operation step " comprises following concrete steps:

Step one: receive the access request control bag that access node sends,

Step 2: if the data flow that access node is initiated is the unique data flow that this via node wants relaying, then the character rate r of access node is set _optfor interval [r _min, r _max] in largest prime, and jump to step 7; Otherwise, continue to perform step 3, wherein, r _minand r _maxthat the character rate pre-set according to aspects such as network delay requirements allows minimum value and allows maximum occurrences respectively,

Step 3: get r=r _minand collision probability parameter Min_P=1 is set, note r _opt=r,

Step 4: calculate access node by the probability P (r) of conflicting by formula (1),

\begin{matrix} P (r) &equiv; P (A_{1, n} \cup A_{2, n} \cup . . . \cup A_{n - 1, n}) \\ = Σ_{i = 1}^{n - 1} P (A_{i, n}) - \underset{1 \leq i \leq j \leq n - 1}{Σ} P (A_{i, n} \cap A_{j, n}) + \underset{1 \leq i \leq j < k \leq n - 1}{Σ} P (A_{i, n} \cap A_{j, n} \cap A_{k, n}) - \\ . . . + {(- 1)}^{n - 2} P (A_{1, n} \cap A_{2, n} \cap . . . \cap A_{n - 1, n}) \\ = Σ_{i = 1}^{n - 1} \frac{1}{LCM (r_{i}, r_{n})} - \underset{1 \leq i \leq j \leq n - 1}{Σ} \frac{1}{LCM (r_{i}, r_{j}, r_{n})} + \underset{1 \leq i \leq j < k \leq n - 1}{Σ} \frac{1}{LCM (r_{i}, r_{j}, r_{k}, r_{n})} - \\ . . . + {(- 1)}^{n - 2} \frac{1}{LCM (r_{1}, r_{2}, . . ., r_{n})} \end{matrix} - - - (1)

Wherein, n represents the sequence number of the data flow that current access node is initiated, and that is, via node is current is providing relay services for n-1 other access nodes; A _i,nrepresent that existing i-th data flow sends with incoming data stream generation symbol this event of conflicting; Between functional symbol ∪ presentation of events between event or relation; Between functional symbol ∩ presentation of events between event and relation; P () represents the event occurrence rate in bracket; represent integer least common multiple,

Step 5: if P (r) is <Min_P, then get Min_P=P (r), and remember r _opt=r,

Step 6: r=r+1, if r≤r _max, proceed to step 4,

Step 7: the character rate controlling to arrange in bag access node in reply is r _opt, then send this reply to access node and control bag,

Step 8: wait-receiving mode is from the packet of access node.