阅读说明：本技术 一种面向无线网络的周期性时隙分配方法 (Wireless network-oriented periodic time slot allocation method ) 是由 杨剑锋 郭成城 于 2021-07-12 设计创作，主要内容包括：本发明提出了一种面向无线网络的周期性时隙分配方法。通过无线网络将多个节点进行连接；构建无线网络节点的时隙参数集合、每个节点的时隙之间的间隔数组；计算无线网络中每个节点的所能接受的总时间间隔,选择所能接受的总时间间隔选择最小值的无线网络中节点作为时隙分配节点,进一步为时隙分配节点的每个时隙需求分配时隙,针对无线网络中除时隙分配节点外剩余的节点为剩余的节点的每个时隙需求分配时隙；时隙分配的延迟检测与判定；本方法实现了分配时节点参数的量化计算和分析,能够在提高分配效率的同时兼顾公平性。(The invention provides a wireless network-oriented periodic time slot allocation method. Connecting a plurality of nodes through a wireless network; constructing a time slot parameter set of wireless network nodes and an interval array between time slots of each node; calculating the acceptable total time interval of each node in the wireless network, selecting the node in the wireless network with the minimum acceptable total time interval as a time slot distribution node, further distributing time slots for each time slot requirement of the time slot distribution node, and distributing time slots for each time slot requirement of the remaining nodes aiming at the remaining nodes except the time slot distribution node in the wireless network; delay detection and determination of time slot allocation; the method realizes the quantitative calculation and analysis of the node parameters during distribution, and can improve the distribution efficiency and take fairness into consideration.)

1. A wireless network-oriented periodic time slot allocation method is characterized by comprising the following specific steps:

step 1, connecting a network SN with f nodes through a wireless network;

step 2, constructing a time slot parameter set of wireless network nodes and an interval array between time slots of each node;

step 3, calculating the acceptable total time interval of each node in the wireless network, selecting the node in the wireless network with the minimum acceptable total time interval as a time slot distribution node, further distributing time slots for each time slot requirement of the time slot distribution node, and distributing time slots for each time slot requirement of the remaining nodes aiming at the remaining nodes except the time slot distribution node in the wireless network;

and 4, delay detection and judgment of time slot allocation.

2. The method for allocating periodic timeslots for a wireless network according to claim 1, wherein the step 1 specifically comprises:

the f nodes transmit data through time slots of a certain channel in the network SN, where the first time slot is denoted as time slot 0, the second time slot is denoted as time slot 1, and so on, each time slot is marked in time sequence, and each time slot is therefore marked with a time slot number.

3. The method of claim 1, wherein the set of timeslot parameters of the wireless network node in step 2 is defined as:

data_i，k＝{BN_i，k，SN_i，k，BSN_i，k}，i∈[1，f]，k∈[1，L]

wherein, the data_i，kSet of time slot parameters, BN, representing the ith node at the kth time in a wireless network_i，kRepresenting the total number of backoff times, SN, of the ith node at the kth time in the wireless network_i，kRepresents the longest back-off step number, BSN, of the ith node at the kth time in the wireless network_i，kThe total backstepping number of the ith node in the wireless network at the kth moment is represented, f represents the number of the nodes in the wireless network, and L represents the number of the moments;

any one of the nodes N_i，i∈[1，f]Requires NT_iTransmitting data in a plurality of time slots;

step 2, the interval array between the time slots of each node is defined as:

wherein M is_iIs an array of intervals, m, between time slots of the ith node in the wireless network_i，0，1The distribution can be skipped after the request time slot of the ith node in the wireless network is distributedMaximum number of allocated slots, m_i，j，j+1For the longest interval between the j +1 th request time slot needing to be allocated and the j request time slot needing to be allocated of the ith node in the wireless network, i E [1, f]，

j∈[1，NT_i]F denotes the number of nodes in the wireless network, NT_iIndicating the number of request time slots of the ith node in the wireless network;

the BN_i，kThe back-off is to the node N_i，kWhen time slot is allocated, the node N is occupied due to the existence of other nodes_i，kRequired time slot, resulting in node N_i，kThe allocation of the required time slots is delayed; total number of receding times BSN_i，kRefers to node N_i，kThe total number of backoff until the next time slot allocation; when the time slot allocation starts, the total backward times of all the nodes are 0;

the SN is_i，kLongest back-off step SN_i，kRefers to node N_i，kThe longest time slot interval number of backward movement in backward movement before next time slot allocation; when the time slot allocation starts, the longest step number of the backward movement of all the nodes is 0;

the BSN_i，kTotal back-off number BSN_i，kRefers to node N_i，kThe total number of steps of backoff performed until the next time slot allocation; when the time slot allocation starts, the total back stepping number of all the nodes is 0;

the M is_iFor node N_i，kWith an allocated interval requirement per slot, for the need of NT_i，kNode N of one time slot_i，kAn interval requirement set M formed by interval requirements between any two adjacent time slots is as follows:

4. the method according to claim 1, wherein the step 3 of calculating the total time interval accepted by each node in the wireless network comprises:

wherein, M'_iIs the acceptable total time interval, m ', of the ith point'_i，j，kIs the maximum number of the time slots which can be skipped after the time slot is allocated to the ith node at the kth moment in the wireless network, and j belongs to [1, NT ∈_i]，NT_i，kIs the total time slot request number of the ith node at the kth time in the wireless network, f represents the total node number, f represents the number of the nodes in the wireless network, NT_iIndicating the number of request time slots of the ith node in the wireless network; k represents the kth time;

step 3, selecting the node in the wireless network with the minimum acceptable total time interval as the time slot distribution node, specifically:

in M'₁，M′₂，...，M′_fOf which the minimum value is M'_min；

The time slot distribution node is the min node in the wireless network;

step 3, allocating a time slot for each time slot requirement of the time slot allocation node, specifically:

the time slot required to be allocated to the first time slot of the min node in the wireless network is 0;

the min node in the wireless network starts from the time slot allocated by the second time slot requirement, and the time slot allocated by each time slot requirement is as follows:

wherein m is_min，jAllocating time slots to the min-th node of the node at the moment k, and adding the number of the allocated time slots and the number of the time slots corresponding to the maximum number of the skipped time slots;

step 3, allocating time slots for each time slot requirement of the remaining nodes except the time slot allocation node in the wireless network specifically includes:

step 3.1: calculating the node N which is arbitrarily allocated with the time slot aiming at the nodes except the time slot allocation node in the wireless network_i，kAccording to the corresponding interval requirement set M_i，kTime slot occupied by the time slot distributed node, and calculating node N_i，kTime slot allocation weight parameter Q_i，k：

Wherein the content of the first and second substances,referred to as the total back-off number coefficient,called the longest step back coefficient;

step 3.2: among nodes for determining all time slots to be allocated, Q_i，kMinimum node N'_i，kThen is node N'_i，kAllocating time slots; if Q is present_i，kIf they are equal, then M is selected_i，kThe smallest node is allocated;

and repeating the step 3.1 and the step 3.2 until all the time slots required by the nodes are allocated.

5. The method of claim 1, wherein the delay detection and determination of the time slot allocation in step 4 is:

for the time slot allocation result obtained in the step 3, an interval requirement set M of any node Ni is allocated to a time slot k if the jth time slot of the node Ni requests; and the j +1 th time slot request of the node Ni is allocated to the time slot k', then:

step delay detection: m is_ij'＝k’-k

Step delay judgment:

a delayed situation occurs: if m is_ij'>m_ijIf so, indicating that the time slot allocation of the node Ni is delayed;

no delay is present: if for node Ni, there is no m_ij'>m_ijIf so, indicating that no delay exists in the time slot allocation;

wherein m is_i，jIs the jth slot request of the ith node;

k is the jth time slot request of the node Ni, and is allocated to the time slot;

k' is the slot to which the j +1 th slot request of node Ni is assigned.

Technical Field

The invention relates to the technical field of wireless network time slot allocation, in particular to a wireless network-oriented periodic time slot allocation method.

Background

The rapid development of wireless network technology enables people to access and acquire internet resources rapidly and randomly at any time and place, and greatly changes communication and life style. With the rise of concepts such as internet plus and internet of things, communication and communication are not limited to people and more extended to people and various hardware devices.

Wi-Fi equipment adopts an IEEE802.11 protocol, and a Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) mechanism adopted by an MAC layer of the protocol can cause uncertainty of transmission delay. The problem is particularly prominent in the fields of internet of things, factory automation control, intelligent traffic and the like with high real-time requirements.

The traditional real-time requirement is mainly concentrated in the field of industrial control and is used for acquiring the running condition of equipment, sending control instructions and the like. In such scenarios, very high requirements are placed on the response time, reliability, and privacy of the communication [ ]. The propagation of wireless signals in an industrial production environment is susceptible to noise interference when the production equipment is in operation. In the industrial field, real-time industrial control application requires that the transmission reliability of data is more than 95%, and meanwhile, the signal transmission delay is not higher than 1.5 times of the sampling processing time of a sensor.

Different from factory noise interference, a plurality of different network protocols and devices are simultaneously operated in free public frequency bands (2.4G and 5G); in such a hybrid wireless network, since the number of nodes is large and different network protocols are operated, collision and collision between the nodes are highly likely. In addition, data packets in the field of industrial control are mainly used for transmitting control information, and in such scenes, the number of data frames is small, the packet length is small, and therefore, a high transmission rate is not needed; and the requirement of the new field of internet of things and internet plus for data transmission rate is relatively high, such as smart cities and smart homes. Therefore, the ieee802.15.4 protocol widely adopted in the industrial control network obviously cannot meet the design requirements of a new scene on high speed and high real-time performance in the hybrid network.

Therefore, the current channel time slot allocation of the Wifi wireless network has the defects of low real-time performance, uncertain delay and the like. This is exactly the problem that the technology in the present invention can solve.

Disclosure of Invention

The technical scheme adopted by the invention for solving the technical problem is a wireless network-oriented periodic time slot allocation method, which comprises the following specific steps:

step 1, connecting a network SN with f nodes through a wireless network;

step 2, constructing a time slot parameter set of wireless network nodes and an interval array between time slots of each node;

step 3, calculating the acceptable total time interval of each node in the wireless network, selecting the node in the wireless network with the minimum acceptable total time interval as a time slot distribution node, further distributing time slots for each time slot requirement of the time slot distribution node, and distributing time slots for each time slot requirement of the remaining nodes aiming at the remaining nodes except the time slot distribution node in the wireless network;

step 4, delay detection and judgment of time slot allocation;

preferably, the step 1 specifically comprises:

f nodes send data through a time slot of a certain channel in the network SN, wherein the first time slot is marked as a time slot 0, the second time slot is marked as a time slot 1, and the like, each time slot is marked according to the time sequence, and each time slot is marked with a time slot number;

preferably, the timeslot parameter set of the radio network node in step 2 is defined as:

data_i，k＝{BN_i，k，SN_i，k，BSN_i，k}，i∈[1，f]，k∈[1，L]

wherein, the data_i，kSet of time slot parameters, BN, representing the ith node at the kth time in a wireless network_i，kRepresenting the total number of backoff times, SN, of the ith node at the kth time in the wireless network_i，kRepresents the longest back-off step number, BSN, of the ith node at the kth time in the wireless network_i，kThe total backstepping number of the ith node in the wireless network at the kth moment is represented, f represents the number of the nodes in the wireless network, and L represents the number of the moments;

any one of the nodes N_i，i∈[1，f]Requires NT_iTransmitting data in a plurality of time slots;

step 2, the interval array between the time slots of each node is defined as:

wherein M is_iIs an array of intervals, m, between time slots of the ith node in the wireless network_i，0，1The maximum number of the allocated time slots, m, can be skipped after the request time slot allocation of the ith node in the wireless network_i，j，j+1For the longest interval between the j +1 th request time slot needing to be allocated and the j request time slot needing to be allocated of the ith node in the wireless network, i E [1, f]，

j∈[1，NT_i]F denotes the number of nodes in the wireless network, NT_iIndicating the number of request time slots of the ith node in the wireless network;

the BN_i，kThe back-off is to the node N_i，kWhen time slot is allocated, the node N is occupied due to the existence of other nodes_i，kRequired time slot, resulting in node N_i，kThe allocation of the required time slots is delayed; total number of receding times BSN_i，kRefers to node N_i，kThe total number of backoff until the next time slot allocation; when the time slot allocation starts, the total backward times of all the nodes are 0;

the SN is_i，kLongest back-off step SN_i，kRefers to node N_i，kThe longest time slot interval number of backward movement in backward movement before next time slot allocation; when the time slot allocation starts, the longest step number of the backward movement of all the nodes is 0;

the BSN_i，kTotal back-off number BSN_i，kRefers to node N_i，kThe total number of steps of backoff performed until the next time slot allocation; when the time slot allocation starts, the total back stepping number of all the nodes is 0;

the M is_iFor node N_i，kWith an allocated interval requirement per slot, for the need of NT_i，kNode N of one time slot_i，kAn interval requirement set M formed by interval requirements between any two adjacent time slots is as follows:

preferably, the step 3 of calculating the total time interval accepted by each node in the wireless network specifically includes:

wherein, M'_iIs the acceptable total time interval, m ', of the ith point'_i，j，kIs the maximum number of the time slots which can be skipped after the time slot is allocated to the ith node at the kth moment in the wireless network, and j belongs to [1, NT ∈_i]，NT_i，kIs the total time slot request number of the ith node at the kth time in the wireless network, f represents the total node number, f represents the number of the nodes in the wireless network, NT_iIndicating the number of request time slots of the ith node in the wireless network; k denotes the kth time.

Step 3, selecting the node in the wireless network with the minimum acceptable total time interval as the time slot distribution node, specifically:

in M'₁，M′₂，...，M′_fOf which the minimum value is M'_min；

The time slot distribution node is the min node in the wireless network;

step 3, allocating a time slot for each time slot requirement of the time slot allocation node, specifically:

the time slot required to be allocated to the first time slot of the min node in the wireless network is 0;

the min node in the wireless network starts from the time slot allocated by the second time slot requirement, and the time slot allocated by each time slot requirement is as follows:

wherein m is_min，jThe node at the moment k is the min node to allocate the time slot, the number of the allocated time slot is added with the number of the skipped-over time slotA time slot number corresponding to the maximum number of time slots;

step 3, allocating time slots for each time slot requirement of the remaining nodes except the time slot allocation node in the wireless network specifically includes:

step 3.1: calculating the node N which is arbitrarily allocated with the time slot aiming at the nodes except the time slot allocation node in the wireless network_i，kAccording to the corresponding interval requirement set M_i，kTime slot occupied by the time slot distributed node, and calculating node N_i，kTime slot allocation weight parameter Q_i，k：

Wherein the content of the first and second substances,the total back-off number of times coefficient,the longest back step coefficient is used;

step 3.2: among nodes for determining all time slots to be allocated, Q_i，kMinimum node N'_i，kThen is node N'_i，kAllocating time slots; if Q is present_i，kIf they are equal, then M is selected_i，kThe smallest node is allocated;

repeating the step 3.1 and the step 3.2 until all the time slots required by the nodes are distributed;

preferably, the delay detection and determination of the time slot allocation in step 4 is:

for the time slot allocation result obtained in the step 3, an interval requirement set M of any node Ni is allocated to a time slot k if the jth time slot of the node Ni requests; and the j +1 th time slot request of the node Ni is allocated to the time slot k', then:

step delay detection: m is_ij’＝k’-k

Step delay judgment:

a delayed situation occurs: if m is_ij’＞m_ijIf so, indicating that the time slot allocation of the node Ni is delayed;

no delay is present: if for node Ni, there is no m_ij＞m_ijIf so, indicating that no delay exists in the time slot allocation;

wherein m is_i,jIs the jth slot request of the ith node;

k is the jth time slot request of the node Ni, and is allocated to the time slot;

k' is the slot to which the j +1 th slot request of node Ni is assigned.

The invention has the beneficial effects that:

the method designs definite parameters for the requirement of the node on the time slot, and quantifies the time slot request through the parameters; the cost of time slot allocation is calculated by means of quantized parameters, and the allocation of time slots is performed by means of a quantization analysis.

The invention has the following characteristics:

and (4) carrying out parameterized allocation. The invention quantifies the time slot allocation in a parameterized way, and the allocation process is clearer;

giving consideration to both efficiency and fairness. The quantitative analysis method can effectively improve the efficiency, and simultaneously can ensure that the time slot allocation requirement of each node can be met as much as possible, thereby giving consideration to both the efficiency and the fairness.

Drawings

FIG. 1: is the integral implementation step of the invention;

FIG. 2: the time slot marking mode in the invention;

FIG. 3: this is the case after the node N1 completes the time slot allocation;

FIG. 4: this is the case after the node N2 completes the time slot allocation;

FIG. 5: this is the case after the time slot assignment is completed by node N3.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention, as the invention will be described in detail, with reference to the following detailed description. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

A first embodiment of the present invention is a method for allocating periodic timeslots for a wireless network, and the specific implementation manner is as follows:

step 1, connecting a network SN with f nodes through a wireless network;

f nodes send data through a time slot of a certain channel in the network SN, wherein the first time slot is marked as a time slot 0, the second time slot is marked as a time slot 1, and the like, each time slot is marked according to the time sequence, and each time slot is marked with a time slot number;

step 2, constructing a time slot parameter set of wireless network nodes and an interval array between time slots of each node;

any one of the nodes N_i，i∈[1，f]Requires NT_iTransmitting data in a plurality of time slots;

step 2, the time slot parameter set of the wireless network node is defined as:

data_i，k＝{BN_i，k，SN_i，k，BSN_i，k}，i∈[1，f]，k∈[1，L]

wherein, the data_i，kSet of time slot parameters, BN, representing the ith node at the kth time in a wireless network_i，kRepresenting the total number of backoff times, SN, of the ith node at the kth time in the wireless network_i，kRepresents the longest back-off step number, BSN, of the ith node at the kth time in the wireless network_i，kThe total backstepping number of the ith node in the wireless network at the kth moment is represented, f represents the number of the nodes in the wireless network, and L represents the number of the moments;

step 2, the interval array between the time slots of each node is defined as:

wherein M is_iIs an array of intervals, m, between time slots of the ith node in the wireless network_i，0，1The maximum number of the allocated time slots, m, can be skipped after the request time slot allocation of the ith node in the wireless network_i，j，j+1For the longest interval between the j +1 th request time slot needing to be allocated and the j request time slot needing to be allocated of the ith node in the wireless network, i E [1, f]，

j∈[1，NT_i]F denotes the number of nodes in the wireless network, NT_iIndicating the number of request time slots of the ith node in the wireless network;

the BN_i，kThe back-off is to the node N_i，kWhen time slot is allocated, the node N is occupied due to the existence of other nodes_i，kRequired time slot, resulting in node N_i，kThe allocation of the required time slots is delayed; total number of receding times BSN_i，kRefers to node N_i，kThe total number of backoff until the next time slot allocation; when the time slot allocation starts, the total backward times of all the nodes are 0;

the SN is_i，kLongest back-off step SN_i，kRefers to node N_i，kThe longest time slot interval number of backward movement in backward movement before next time slot allocation; when the time slot allocation starts, the longest step number of the backward movement of all the nodes is 0;

the BSN_i，kTotal back-off number BSN_i，kRefers to node N_i，kThe total number of steps of backoff performed until the next time slot allocation; when the time slot allocation starts, the total back stepping number of all the nodes is 0;

the M is_iFor node N_i，kWith an allocated interval requirement per slot, for the need of NT_i，kNode N of one time slot_i，kThe interval between any two adjacent time slots is requiredThe formed interval requirement set M is as follows:

if at node N_i，kWhen waiting for any one time slot allocation, the number of skipped time slots exceeds the corresponding time interval, which indicates that allocation delay occurs;

step 3, calculating the acceptable total time interval of each node in the wireless network, selecting the node in the wireless network with the minimum acceptable total time interval as a time slot distribution node, further distributing time slots for each time slot requirement of the time slot distribution node, and distributing time slots for each time slot requirement of the remaining nodes aiming at the remaining nodes except the time slot distribution node in the wireless network;

step 3, calculating the total time interval accepted by each node in the wireless network, specifically:

wherein, M'_iIs the acceptable total time interval, m ', of the ith point'_i，j，kIs the maximum number of the time slots which can be skipped after the time slot is allocated to the ith node at the kth moment in the wireless network, and j belongs to [1, NT ∈_i]，NT_i，kIs the total time slot request number of the ith node at the kth time in the wireless network, f represents the total node number, f represents the number of the nodes in the wireless network, NT_iIndicating the number of request time slots of the ith node in the wireless network; k denotes the kth time.

Step 3, selecting the node in the wireless network with the minimum acceptable total time interval as the time slot distribution node, specifically:

in M'₁，M′₂，...，M′_fOf which the minimum value is M'_min；

The time slot distribution node is the min node in the wireless network;

step 3, allocating a time slot for each time slot requirement of the time slot allocation node, specifically:

the time slot required to be allocated to the first time slot of the min node in the wireless network is 0;

the min node in the wireless network starts from the time slot allocated by the second time slot requirement, and the time slot allocated by each time slot requirement is as follows:

wherein m is_min，jAllocating time slots to the min-th node of the node at the moment k, and adding the number of the allocated time slots and the number of the time slots corresponding to the maximum number of the skipped time slots;

step 3, allocating time slots for each time slot requirement of the remaining nodes except the time slot allocation node in the wireless network specifically includes:

step 3.1: calculating the node N which is arbitrarily allocated with the time slot aiming at the nodes except the time slot allocation node in the wireless network_i，kAccording to the corresponding interval requirement set M_i，kTime slot occupied by the time slot distributed node, and calculating node N_i，kTime slot allocation weight parameter Q_i，k：

Wherein the content of the first and second substances,the coefficient of the total number of backward times is obtained,called the longest step back coefficient;

step 3.2: among nodes for determining all time slots to be allocated, Q_i，kMinimum node N'_i，kThen is node N'_i，kAllocating time slots; if Q is present_i，kIf they are equal, then M is selected_i，kThe smallest node is allocated;

repeating the step 3.1 and the step 3.2 until all the time slots required by the nodes are distributed;

step 4, delay detection and judgment of time slot allocation;

step 4, the delay detection and determination of the time slot allocation is:

for the time slot allocation result obtained in the step 3, an interval requirement set M of any node Ni is allocated to a time slot k if the jth time slot of the node Ni requests; and the j +1 th time slot request of the node Ni is allocated to the time slot k', then:

step delay detection: m is_ij’＝k’-k

Step delay judgment:

a delayed situation occurs: if m is_ij’＞m_ijIf so, indicating that the time slot allocation of the node Ni is delayed;

no delay is present: if for node Ni, there is no m_ij’＞m_ijIf so, indicating that no delay exists in the time slot allocation;

wherein m is_i，jIs the jth slot request of the ith node;

k is the jth time slot request of the node Ni, and is allocated to the time slot;

k' is the slot to which the j +1 th slot request of node Ni is assigned.

A second embodiment of the present invention is described below with reference to fig. 1 to 5, and the second embodiment of the present invention is as follows:

the first step, a network SN with f nodes is connected through a wireless network;

f nodes send data through a time slot of a certain channel in the network SN, wherein the first time slot is marked as a time slot 0, the second time slot is marked as a time slot 1, and the like, each time slot is marked according to the time sequence, and each time slot is marked with a time slot number;

when the marking of the time slot is actually realized, the time slot can be marked from 0 again according to the use requirement;

for example, the slot numbering as shown in fig. 2 can be performed for the slots, respectively: slot 0, slot 1, slot 2, slot 3, etc.

In the second step, any node Ni (0< i < ═ f) needs NTi time slots to transmit data, and has the following parameters:

step 2.1, Total Backward times BNi

The back-off refers to that when the time slot is allocated to the node Ni, the time slot required by the node Ni is occupied due to the existence of other nodes, so that the allocation of the time slot required by the node Ni is delayed. The total backoff number BNi is the total backoff number of the node Ni before the next time slot allocation. At the start of the time slot allocation, the total number of backoff times of all nodes is 0.

Step 2.2, longest Back-off step number SNi

The longest backoff step number SNi is the longest time slot interval number for backoff from the node Ni until the next time slot allocation. At the start of the slot allocation, the longest backoff steps of all nodes are 0.

Step 2.3, Total Back off number BSNi

The total back-off number of steps BSNi refers to the total number of steps of back-off that the node Ni takes until the next time slot allocation. At the start of the slot assignment, the total back-off number for all nodes is 0.

Step 2.4, spacing requirements between corresponding time slots of Ni

For a node Ni, each time slot of the node Ni has an allocated interval requirement, and for a node Ni requiring NTi time slots, an interval requirement set M formed by interval requirements between any two adjacent time slots is as follows:

M(Ni)＝{mi0,mi1,miNTi-1}

wherein, mi0 can skip the maximum number of the allocated time slots after requesting the time slot allocation for node Ni; mi1 is the longest interval between the second time slot to be allocated and the first time slot to be allocated; mi2 is the longest interval between the third time slot to be allocated and the second time slot to be allocated; and in analogy, miNTi-1 is the longest interval between the last time slot to be allocated and the penultimate time slot to be allocated.

If the number of skipped time slots exceeds the corresponding time interval while node Ni waits for any time slot allocation, this indicates that an allocation delay has occurred;

for example, for a network with 3 nodes (f ═ 3), N1, N2, and N3, respectively, correspond to the following table 1:

table 1: network of 3 nodes (f ═ 3)

Third step, allocation of time slots

Step 3.1, for f nodes, calculate the total time interval accepted for each node:

for the nodes in table 1, as shown in table 2:

table 2: parameter table of 3 nodes

Node point	Set of interval requirements M	Total time interval Mi
			N1	M(N1)＝{2,4}	6
N2	M(N2)＝{1,4,3}	8
			N3	M(N3)＝{1,3,3}	7

Step 3.2, selecting the node with the minimum Mi, and allocating a time slot to each time slot requirement of the node, wherein the first time slot requirement is allocated to the time slot 0, and the rest time slots are calculated according to M (Ni) and allocated to the corresponding time slots;

according to tables 1 and 2, when the total time interval M1 of the current N1 is minimum, the node M1 is allocated, resulting in the result shown in fig. 3.

Step 3.3, for the rest nodes, calculating a node Ni which is arbitrarily the allocated time slot according to the corresponding interval requirement set M and the time slot occupied by the node of the allocated time slot, and calculating a time slot allocation weight parameter Qi of the node Ni:

wherein the content of the first and second substances,referred to as the total back-off number coefficient,referred to as the longest back-off step number coefficient.

According to tables 1 and 2, the results shown in table 3 were obtained by calculation:

table 3: parameter table of 2 nodes

Step 3.4, solving the node Ni 'with the minimum Qi in all the nodes of the time slot to be distributed, and then distributing the time slot for the node Ni'; if the Qi is equal, selecting the node with the minimum Mi for distribution;

from table 1, table 2, table 3 and table 4, it can be seen that the time slot allocation to the node N1 does not occupy the time slot allocation to the next nodes N2 and N3, and Q2 corresponding to the node N2 and Q3 corresponding to the node N3 are both 0, and since M2< M3, the node N3 is then allocated, and the allocation result is shown in fig. 4.

And 3.5, repeating the step 3.3 and the step 3.4 until all the time slots required by the nodes are distributed.

And finally, the time slot allocation to the node N2 is completed.

The fourth step, delay detection and judgment

For the time slot distribution result obtained from the third step, the interval requirement set M of any node Ni is distributed to a time slot k if the jth time slot request of the node Ni is received; and the j +1 th time slot request of the node Ni is allocated to the time slot k', then:

mij'＝k’-k

if mij' > mij, it indicates that the time slot allocation to node Ni is delayed;

if there is no mij' > mij for node Ni, this indicates that there is no delay in the slot allocation.

From the assignment results for the nodes shown in table 1, as shown in fig. 5, it is calculated that:

table 4: interval requirement set of 3 nodes and interval after actual distribution

Node point	Set of interval requirements M	Actual post-allocation interval
			N1	M(N1)＝{2,4}	{2,4}
N2	M(N2)＝{1,4,3}	{2,2,3}
			N3	M(N3)＝{1,3,3}	{1,3,3}

Where a delay of 1 slot length occurs at N2.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.