阅读说明：本技术 一种智能电网中微功率无线通信网络的业务数据调度方法 (Service data scheduling method of micropower wireless communication network in smart power grid ) 是由 黄俊伟 李超 何绍喜 杨正海 陶功平 于 2021-01-18 设计创作，主要内容包括：本发明涉及一种智能电网中微功率无线通信网络的业务数据调度方法,属于电力物联网领域。该方法包括：根据网络中不同业务类型的不同需求,将业务数据合理的划分静态优先级；同步智能电网中的微功率无线通信网络,将时间离散化为一系列的时隙t＝1,2,…；周期性检测网络中传输的数据包,丢弃剩余时间耗尽前无法传送到目的节点的数据包；基于动态优先级的数据包调度机制。本发明将业务数据进行了合理的分类,明确了各类业务数据的需求；节点周期性丢弃不合格的数据包,避免了网络资源的浪费；基于动态优先级的业务数据包调度方法,满足了高优先级业务数据对于实时性和可靠性的要求,同时避免了低优先级业务数据的饿死问题。(The invention relates to a service data scheduling method of a micropower wireless communication network in an intelligent power grid, and belongs to the field of power internet of things. The method comprises the following steps: according to different requirements of different service types in a network, service data are reasonably divided into static priorities; the method comprises the steps that a micro-power wireless communication network in a synchronous smart grid is subjected to time discretization to form a series of time slots t, wherein t is 1,2 and …; periodically detecting data packets transmitted in the network, and discarding the data packets which cannot be transmitted to a destination node before the remaining time is exhausted; a dynamic priority based packet scheduling mechanism. The invention reasonably classifies the service data and determines the requirements of various service data; the nodes periodically discard unqualified data packets, so that the waste of network resources is avoided; the dynamic priority-based service data packet scheduling method meets the requirements of high-priority service data on real-time performance and reliability, and simultaneously avoids the problem of starvation of low-priority service data.)

1. A service data scheduling method of a micropower wireless communication network in an intelligent power grid is characterized by comprising the following steps: the method comprises the following steps:

s11: classifying service data in a network, comprising: determining the static priority of a service data packet and the service waiting time of the service data packet;

s12: the method comprises the steps that a micro-power wireless communication network in a synchronous smart grid is subjected to time discretization to form a series of time slots t, wherein t is 1,2 and …;

s13: when a node generates a data packet, setting the static priority and the transmission remaining time of data according to the service type of the data packet, and then adding the static priority information of the data and the transmission remaining time information of the data into the data packet;

s14: maintaining four queues in each node according to four static priorities corresponding to the data packets, and putting the data packets transmitted by the nodes into corresponding priority queues according to the static priorities of the data packets;

s15: on the basis of network synchronization, subtracting t from the transmission residual time of all data packets in the node every time slot t, then checking the transmission residual time of each data packet, and discarding the data packet if the data packet is detected to be incapable of being transmitted to a target node on time, so as to avoid wasting network resources;

s16: when the sending time slot of the node comes, the scheduler comprehensively considers the static priority of the data packets in the four queues and the transmission residual time of the data packets, and selects the data packet with the highest dynamic priority to send.

2. The service data scheduling method of the micropower wireless communication network in the smart grid according to claim 1, wherein the method comprises the following steps: in the S11, the service classification method includes: and defining the service functions in the network according to the interconnection and intercommunication technical specification of the intelligent power grid, the standardized route draft of the intelligent power grid and the application scene of the micropower wireless communication network.

3. The service data scheduling method of the micropower wireless communication network in the smart grid according to claim 1, wherein the method comprises the following steps: in S13, each data packet transmitted in the network includes static priority information of the data and transmission remaining time information.

4. The service data scheduling method of the micropower wireless communication network in the smart grid according to claim 1, wherein the method comprises the following steps: in S15, the transmission remaining time of the data packet is periodically updated, and the unqualified data packet is discarded in time, so as to avoid the waste of network resources and improve the throughput of the network.

5. The service data scheduling method of the micropower wireless communication network in the smart grid according to claim 1, wherein the method comprises the following steps: in step S15, the calculation method for determining whether the packet can be transmitted to the destination node in time is:

D＝T_i-(H_i×τ)，D≥0

where D represents the relative remaining time of the data packet, T_iRepresenting the remaining time for the data packet to be transmitted to the destination node,H_ithe number of the residual hops for transmitting the data packet to the destination node is represented, and tau represents the minimum time for successfully transmitting the data packet to the next hop node in the node; when D < 0, it means that the packet cannot be theoretically transmitted to the destination node, and the packet is discarded.

6. The service data scheduling method of the micropower wireless communication network in the smart grid according to claim 1, wherein the method comprises the following steps: in S16, the method for calculating the dynamic priority of the data packet includes:

wherein the content of the first and second substances,

wherein j represents the static priority of the data packet, i represents the emergency degree of the data packet transmission, the value is an integer of 1-4, the larger the numerical value is, the more the data packet needs to be transmitted urgently, gamma is a weighting coefficient which tends to be relative to the remaining time, and when the value of gamma is large enough, the more the data packet needs to be transmitted urgently.

7. The service data scheduling method of the micropower wireless communication network in the smart grid according to claim 1, wherein the method comprises the following steps: in S16, the scheduling algorithm comprehensively considers the static priority of the data packet and the transmission remaining time of the data packet, and determines the sending priority of the data packet together, so as to ensure the priority transmission of the data packet with high priority, and avoid the starvation problem caused by the fact that the data packet with low priority cannot be sent all the time.

Technical Field

The invention belongs to the field of power internet of things, and relates to a service data scheduling method of a micro-power wireless communication network in an intelligent power grid.

Background

The micropower wireless communication network is a multi-hop self-organizing wireless sensor network capable of bidirectional communication applied to a smart grid. In practical application, the micropower wireless communication network can not only keep universality with a power line carrier communication network and coexist with the power line carrier communication network, but also make up for the disadvantages of the power line carrier communication in certain scenes. The developed micropower wireless communication module is put into equipment such as a concentrator, an electric energy meter and a collector, and the functions of information acquisition, equipment control, emergency report and the like of intelligent power distribution and utilization equipment can be realized.

The micro-power wireless communication network may be a tree topology or a mesh topology, and a structure of the micro-power wireless communication network of the tree topology is shown in fig. 1. The communication module connected with the concentrator is a main communication module called a central coordinator (cco) (central coordinator), is responsible for receiving and transmitting data between the concentrator and the collector or between the concentrator and the electric energy meter, and also has the functions of networking control, network maintenance management and the like. The communication module connected with the collector or the electric energy meter is divided into a proxy coordinator pco (proxycorderator) and a station sta (station) according to roles in the network. In the micropower network, the outermost node has no relay function, called station sta (station), and the node serving as the relay function is called proxy coordinator pco (proxy coordinator). Due to changes in network topology, the roles of PCO and STA may be switched with each other.

At present, with the construction of a smart grid, the types of data required to be collected by a micro-power wireless communication network gradually increase. On one hand, the electric energy meter has higher expansibility, flexibility and reusability by the implementation of a novel electric energy meter protocol, so that the electric energy meter can be used as an access point of a home internal sensor network to realize functions of multi-meter centralized meter reading, electric appliance management, abnormality detection and the like. On the other hand, the transmission rate of the micropower wireless communication network adopting the new protocol is faster. Currently, the broadband PLC technology has become one of the main communication means in the fields of smart grid, energy management, smart home, photovoltaic power generation, electric vehicle charging, and the like. The micro-power wireless communication network technology and the broadband PLC communication technology are compatible and complementary in advantages, and the micro-power wireless communication network technology and the broadband PLC communication technology can be widely applied to the fields.

The increase of the transmitted data types brings differentiation to the demands of different service data. Therefore, the micropower wireless communication network needs to adopt a reasonable service data scheduling method to solve the problems of classification of different service data, service data queuing in nodes, requirements of high-priority services on instantaneity and reliability and the like.

However, in practical applications, the current micropower wireless communication network has the following problems: the classification of the service functions is lacked, and the requirements of different service functions cannot be met; in a bidirectional interactive network, the transmission of data packets often has a deadline, and the data packets exceeding the deadline waste network resources; aiming at the problem of queuing service data in nodes, the conventional micropower network simply adopts a first-come-first-serve strategy, cannot meet the requirement of timely reporting of emergency events, and brings potential hidden danger.

Disclosure of Invention

In view of this, the present invention provides a method for scheduling service data of a micro-power wireless communication network in a smart grid. Classifying service data in a network, comprising: determining the static priority of a service data packet and the service waiting time of the service data packet; the method comprises the steps that a micro-power wireless communication network in a synchronous electricity utilization information acquisition system disperses time into a series of time slots t which are 1,2 and …; periodically detecting data packets transmitted in the network, and discarding the data packets which cannot be transmitted to a destination node before the remaining time is exhausted; a dynamic priority based packet scheduling mechanism.

In order to achieve the purpose, the invention provides the following technical scheme:

a service data scheduling method of a micro-power wireless communication network in a smart grid comprises the following steps:

s11: classifying service data in a network, comprising: determining the static priority of a service data packet and the service waiting time of the service data packet;

s12: the method comprises the steps that a micro-power wireless communication network in a synchronous smart grid is subjected to time discretization to form a series of time slots t, wherein t is 1,2 and …;

s13: when a node generates a data packet, setting the static priority and the transmission remaining time of data according to the service type of the data packet, and then adding the static priority information of the data and the transmission remaining time information of the data into the data packet;

s14: and maintaining four queues in each node according to the four static priorities corresponding to the data packets, and putting the data packets transmitted by the nodes into corresponding priority queues according to the static priorities of the data packets.

S15: on the basis of network synchronization, subtracting t from the transmission residual time of all data packets in the node every time slot t, then checking the transmission residual time of each data packet, and discarding the data packet if the data packet is detected to be incapable of being transmitted to a target node on time, so as to avoid wasting network resources;

s16: when the sending time slot of the node comes, the scheduler comprehensively considers the static priority of the data packets in the four queues and the transmission residual time of the data packets, and selects the data packet with the highest dynamic priority to send.

Optionally, in S11, the service classification method includes: and defining the service functions in the network according to the interconnection and intercommunication technical specification of the intelligent power grid, the standardized route draft of the intelligent power grid and the application scene of the micropower wireless communication network.

Optionally, in S13, each data packet transmitted in the network includes static priority information of the data and transmission remaining time information.

Optionally, in S15, the transmission remaining time of the data packet is periodically updated, and the unqualified data packet is discarded in time, so as to avoid waste of network resources and improve the throughput of the network.

Optionally, in step S15, the calculation method for determining whether the data packet can be transmitted to the destination node in time includes:

D＝T_i-(H_i×τ)，D≥0

where D represents the relative remaining time of the data packet, T_iIndicating transmission of data packets to destination nodeThe remaining time of (A), H_iRepresenting the number of hops remaining for the packet to be delivered to the destination node and tau representing the minimum time taken for the packet to be successfully transmitted to the next hop node in the node. When D < 0, it means that the packet cannot be theoretically transmitted to the destination node, and the packet is discarded.

Optionally, in S16, the method for calculating the dynamic priority of the data packet includes:

wherein the content of the first and second substances,

wherein j represents the static priority of the data packet, i represents the emergency degree of the data packet transmission, the value is an integer of 1-4, the larger the numerical value is, the more the data packet needs to be transmitted urgently, gamma is a weighting coefficient which tends to be relative to the remaining time, and when the value of gamma is large enough, the more the data packet needs to be transmitted urgently.

Optionally, in S16, the scheduling algorithm comprehensively considers the static priority of the data packet and the transmission remaining time of the data packet, and determines the sending priority of the data packet together, so as to ensure the priority transmission of the data packet with high priority, and avoid the starvation problem caused by that the data packet with low priority cannot be sent all the time.

The invention has the beneficial effects that: the invention considers the application scene of the micropower wireless network and the classification of the service functions, and reasonably divides the service functions into priority levels according to the service requirements. On the basis of network synchronization, the transmission state of the data packet is periodically updated and detected, and the data packet which cannot be transmitted to the destination node before the transmission residual time is exhausted is discarded in time, so that the network overhead is reduced; the invention selects the data packet with the highest dynamic priority in the node to send by calculating the dynamic priority of the data packet in the node, meets the requirements of the high-priority data packet on the real-time performance and the reliability, and simultaneously solves the problem of starvation caused by the fact that the low-priority data packet is always preempted.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

fig. 1 a network topology of a micropower wireless communication network;

FIG. 2 is a schematic diagram of queue partitioning of packets within a node;

FIG. 3 is a dynamic two-dimensional priority table for a value of γ of 1;

FIG. 4 is a schematic flow chart of an embodiment of the present invention.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

The invention provides a service data scheduling method of a micropower wireless communication network in an intelligent power grid, which comprises the following steps:

s11: classifying service data in a network, comprising: determining the static priority of a service data packet and the service waiting time of the service data packet;

according to the application scene in the smart grid, the micropower wireless communication network is responsible for the service functions of equipment information acquisition, equipment control, demand response, load control, emergency reporting and the like. These traffic functions vary in their importance and in their tolerance to delay.

In order to respond effectively to the requirements of various service functions, management of various services by classification is required. The specific method is that according to the importance degree of the service, reasonable priorities are divided for various services, and then the requirements of various priority services on time delay are determined. As shown in table 1 below, a service classification schematic of the present invention is shown.

TABLE 1

S12: the method comprises the steps that a micro-power wireless communication network in a synchronous smart grid is subjected to time discretization to form a series of time slots t, wherein t is 1,2 and …;

in micropower wireless communication networks, synchronization of network devices is achieved by transmitting beacon frames in beacon slots. All devices in the network are synchronized to a common clock, facilitating the maintenance of time slots and the management of data packets.

S13: when a node generates a data packet, setting static priority information and transmission remaining time of the data packet according to the service type of the data packet, and then adding the static priority information and the transmission remaining time information of the data into the data packet;

s14: and maintaining four queues in each node according to the four static priorities corresponding to the data packets, and putting the data packets transmitted by the nodes into corresponding priority queues according to the static priorities of the data packets. The data packets in each queue have the same static priority, and the data packets with short transmission residual time are arranged at the head of the queue and are preferentially scheduled;

intra-node queue partitioning is illustrated in fig. 2, where the numbers represent the four static priorities of packets within a node.

S15: on the basis of network synchronization, subtracting t from the transmission residual time of all data packets in the node every time slot t, then checking the transmission residual time of each data packet, and discarding the data packet if the data packet is detected to be incapable of being transmitted to a target node on time, so as to avoid wasting network resources;

since the data packet with short transmission remaining time in each queue is arranged at the head of the queue, the detection of the data packet is started from the head of each queue until the qualified data packet is detected.

S16: when the sending time slot of the node comes, the scheduler comprehensively considers the static priority of the data packets in the four queues and the transmission residual time of the data packets, and selects the data packet with the highest dynamic priority to send.

Further, in step S15, the calculation method for determining whether the packet can be transmitted to the destination node in time includes:

D＝T_i-(H_i×τ)，D≥0

where D represents the relative remaining time of the data packet, T_iIndicating the remaining time, H, for the transmission of the data packet to the destination node_iRepresents the number of remaining hops for the data packet to be transmitted to the destination node, and tau represents the minimum time for the data packet in the node to be successfully transmitted to the next hop node and then receive the ACK frame of the node. When D < 0, it means that the packet cannot be theoretically transmitted to the destination node, and the packet is discarded.

Further, in step S16, the method for calculating the dynamic priority of the data packet includes:

wherein the content of the first and second substances,

wherein j represents the static priority of the data packet, i represents the urgency of the data packet transmission, the value is an integer between 1 and 4, the larger the value is, the more urgent the data packet needs to be transmitted, γ is a weighting coefficient inclined to the remaining time, when the value of γ is large enough, the algorithm is equivalent to an earliest deadline first algorithm (EDF) based on the relative remaining time of the data packet, after interchanging the positions of i and j in the above formula, γ becomes a weighting coefficient inclined to the priority of the data packet, the algorithm is equivalent to an algorithm (PQ) based on the priority of the data packet. And the specific values of the positions i and j and the gamma are selected according to the actual performance condition. Fig. 3 is a dynamic two-dimensional priority table when γ is 1, and the numbers in the table indicate the dynamic priority of the corresponding packets, and the larger the number is, the higher the priority of the packet is.

Finally, a flow chart of the embodiment of the invention is shown in fig. 4.

The invention has the beneficial effects that: the invention periodically updates and detects the transmission state of the data packet on the basis of network synchronization, and discards the data packet which cannot be transmitted to the destination node before the transmission residual time is exhausted in time, thereby reducing the network overhead. The invention selects the data packet with the highest dynamic priority in the node to send by calculating the dynamic priority of the data packet in the node, meets the requirements of the high-priority data packet on the real-time performance and the reliability, and simultaneously solves the problem of starvation caused by the fact that the low-priority data packet is always preempted.

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.