阅读说明：本技术 一种高效自适应跨pan传递时隙分配比例信息的方法 (Method for efficiently and adaptively transmitting time slot distribution proportion information across PAN ) 是由 李宁 宋瑞良 任智 苏新 郭黎 周杨 于 2021-06-16 设计创作，主要内容包括：本发明涉及信息传输领域,尤其涉及一种高效自适应跨PAN传递时隙分配比例信息的方法；在一个网络中,包括PNC节点、网桥节点、普通节点和边缘节点；本发明采用了“受限泛听”、用保留字段或保留值携带信息(不增加控制开销)的思路,自适应地借助网桥节点、单个或多个边缘节点,将两个网络中一个网络的时隙分配比例信息及时、高效地传递给另一个网络；本发明在多PAN太赫兹无线个域网络中,在不增加额外的数据开销的情况下,高效及时地将自身网络中通信类型所占的时隙比例信息传递给另一个网络中的PNC；从而使相邻PAN的PNC在时隙分配时能够有意识地避免数据帧的碰撞,从而提高数据帧传送成功率、网络吞吐量和信道带宽利用率,也有利于降低数据帧传送延迟。(The invention relates to the field of information transmission, in particular to a method for distributing proportion information in an efficient self-adaptive cross-PAN transmission time slot; in a network, comprising PNC nodes, bridge nodes, regular nodes and edge nodes; the invention adopts the thinking of 'limited general listening' and carrying information (without increasing control overhead) by using reserved fields or reserved values, adaptively transfers the time slot allocation proportion information of one network of two networks to the other network in time and efficiently by means of bridge nodes and single or multiple edge nodes; in the multi-PAN terahertz wireless personal area network, time slot proportion information occupied by communication types in the network is efficiently and timely transmitted to a PNC in another network under the condition that extra data overhead is not increased; therefore, the PNC of the adjacent PAN can consciously avoid the collision of data frames during time slot allocation, thereby improving the success rate of data frame transmission, the network throughput and the utilization rate of channel bandwidth, and being beneficial to reducing the transmission delay of the data frames.)

1. A method for efficient adaptive slot allocation ratio information transfer across a PAN, comprising the steps of:

(1) in the CAP period of the superframe, central controllers PNC in two adjacent PAN networks respectively calculate time slot allocation proportion information, write the calculated time slot allocation proportion information into a time slot request reply frame, and send the time slot request reply frame out;

(2) in the CAP period of a superframe, after nodes in two adjacent PAN networks receive a time slot request reply frame, judging whether the nodes are bridge nodes or edge nodes; if the node is a bridge node and a frame is to be sent in the current superframe, starting the operation of transmitting the time slot allocation proportion information by the node, and executing the step (3); if the node is an edge node and the gateway node does not send frames but sends frames in the current superframe, starting the operation of transmitting time slot allocation proportion information by the node, and executing the step (4);

(3) in the CAP period of the superframe, the bridge node extracts the time slot allocation proportion information in the time slot request reply frame and stores the time slot allocation proportion information of the PAN network with higher priority; in a CTAP period, the network bridge node writes the stored time slot allocation proportion information into each data frame or ACK frame to be sent, and then sends the data frame or ACK frame; in a CTAP period, the central controllers PNC in two adjacent PAN networks monitor channels, and when a data frame or an ACK frame which comes from a bridge node and has time slot distribution proportion information is monitored, the time slot distribution proportion information is extracted, and the monitoring is stopped; then the central controller PNC judges whether the extracted time slot allocation proportion information is the same as the self-stored time slot allocation proportion information; if the current time slot allocation proportion information is different from the current time slot allocation proportion information, adjusting the time slot allocation condition of the next superframe in the PAN according to the extracted information, and updating the stored time slot allocation proportion information;

(4) in the CAP period of a superframe, the edge node extracts the time slot allocation proportion information in the time slot request reply frame for storage; in the CTAP period of the superframe, before sending a data frame or an ACK frame, if an edge node receives frames sent by other edge nodes, extracting the time slot allocation proportion information and replacing the self-stored time slot allocation proportion information; before sending a frame, the edge node writes the stored time slot allocation proportion information into a data frame or an ACK frame to be sent, and then sends the data frame or the ACK frame; in a CTAP period of a superframe, a central controller PNC monitors a channel, and when a data frame or an ACK frame which comes from an edge node and has time slot distribution proportion information is monitored, the time slot distribution proportion information is extracted and compared with the time slot distribution proportion information stored by the central controller PNC; if the difference is not the same, the time slot distribution condition of the next superframe in the PAN is adjusted according to the extraction information, and the stored time slot distribution proportion information is updated.

2. The method according to claim 1, wherein the timeslot allocation proportion information is a proportion of 4 different types of timeslots in all allocated timeslots, the timeslot types are divided according to differences between a source node and a destination node using the timeslots, and there are 4 types in total, specifically: the source and destination are both time slots of a common node; the source is a time slot of the common node and the destination is an edge node; the source is a time slot of the edge node and the destination is a common node; both the source and destination are time slots of the edge node.

3. The method of claim 1, wherein the ratio of the timeslot allocation ratio information is a fraction or integer belonging to [0,1] interval; dividing the [0,1] interval into 4 cells which are equal in length and 0.25 in length, and using 2bits to represent which cell the proportion value in the time slot allocation proportion information belongs to; the corresponding relation between the 2bits value and the cell is as follows: 00- (0, 0.25), 01- (0.25, 0.5), 10- (0.5, 0.75), 11- (0.75, 1).

Technical Field

The invention relates to the field of information transmission, in particular to a method for distributing proportion information in an efficient self-adaptive cross-PAN transmission time slot.

Background

With the explosive growth of wireless data traffic over the last few years, it is expected that data rates will soon reach Tbps. However, upcoming 5G networks can only provide gigabit per second (Gbps) transmission speeds. In the face of the ever-increasing demand for high data rates, terahertz (0.1-10 terahertz) communication is assumed to be one of the key technologies of the next generation ultra-high speed wireless systems. The terahertz wireless personal area network is a short-distance, ultra-high-speed and central wireless network taking THz waves as carriers, any two nodes in the network can directly carry out data communication, and the terahertz wireless personal area network has the characteristics of small external interference, high data transmission rate and the like, and is mainly applied to smart homes or scenes such as short-distance wireless data downloading centers and the like in indoor environments. Due to the serious path loss of the terahertz frequency band and the large influence of molecular absorption in the atmosphere, the communication range of the terahertz wireless personal area network is only about 10 meters, so how to expand the communication range of a single wireless personal area network while maintaining high-speed data transmission becomes the focus of research of more and more scholars.

The terahertz wireless personal area network (THz-WPAN) is a short-distance ultra-high-speed wireless self-organizing network and can be composed of one or more micro-networks (PANs). A piconet includes a plurality of individual, generic nodes (DEVs), and of these DEVs, a DEV with sufficient capabilities may become a central controller, the PNC, to assume the role of a piconet coordinator. The PNC provides basic networking information by periodically broadcasting beacon frames (beacons) and is used to complete synchronization throughout the piconet. In addition, the PNC also controls access by the DEVs to channel time resources in the superframe. In a terahertz Wireless Personal Area Network (WPAN), any two DEVs can directly transmit data, and the highest data transmission rate is as high as more than 10 Gbps;

a multi-PAN terahertz wireless personal area network (MP-THz-WPAN) is composed of two or more WPANs. Both the intra-WPAN and inter-WPAN nodes may be in data communication with each other. inter-PAN communication of a multi-PAN terahertz wireless personal area network occurs between two different WPANs. Each WPAN is composed of several DEVs, wherein a certain node with higher priority competes to become the central controller PNC of the network, and nodes located in the overlapping area of two WPANs are called bridges (bridges), which mainly function to coordinate the synchronization of the two WPANs by forwarding heartbeat messages.

The network running time of the multi-PAN terahertz wireless personal area network cross-PAN communication network model consists of continuous coordinated superframes, the specific time interval distribution of each coordinated superframe structure is shown in figure 1, and the network running time mainly comprises 4 time intervals with a sequence, namely: the Beacon Alignment Period (BAP), the CAP Period and the 2 differently-acting CTAP periods are a Normal CTAP (N-CTAP) and a Public CTAP (P-CTAP), respectively. In a BAP period, the PNC in each WPAN respectively broadcasts beacon frames in respective corresponding queue periods, and the frames comprise the basic information of the nodes of the WPAN and the time and duration information of each period; the CAP time periods of 2 WPANs are the same, nodes with data transmission requirements respectively send time slot request frames to different PNCs in the CAP time period according to different WPANs, the PNCs can perform data transmission after successfully allocating time slots, in addition, during the coordinated synchronization of the two WPANs, bridge nodes align beacon frames sent by the two PNCs by broadcasting heartbeat messages in the time period, and the mechanism of accessing channels in the time period is the same as that adopted in the CAP time period of a common superframe; the N-CTAP period and the P-CTAP period are divided into a plurality of CTAs with the same size and are mainly allocated to each DEV for data transmission, wherein the N-CTAP period mainly aims at data in the WPAN network, the P-CTAP period is used for data transmission of a link related to a bridge node, namely mainly aims at data between the WPAN networks, and a TDMA mechanism is adopted when the two periods are accessed into a channel; the P-CTAP period is again divided into two segments, with P-CTAP1 being primarily used for data transfer between nodes and bridge nodes within the WPAN1, and P-CTAP2 being primarily used for data transfer between the WPAN2 node and bridge nodes.

In a WPAN, an edge node is a node located in the communication range of other WPAN common nodes, and the communication of the edge node is interfered by other WPAN nodes; the four nodes in an MP-THz-WPAN are described below in conjunction with FIG. 2.

The PNC node: refers to the central nodes of the individual PANs, such as nodes PNC1 and PNC2 in fig. 2, each PAN has only one PNC node, and the PNC nodes of different PANs cannot communicate directly.

An internetwork node: a node capable of communicating with the PNC nodes of both PANs, such as node A in FIG. 2; the type node transmits data in the P-CTAP period.

And (3) common nodes: refers to DEV nodes that can only communicate with nodes of the PAN where they are located, such as nodes 1, 3, 4, 5 and nodes a, b, c in fig. 2; the type node transmits data in the N-CTAP period;

edge nodes: refers to nodes within communication range with other PAN nodes, such as node 2 and node d in fig. 2; the type node transmits data in the N-CTAP period, but may be interfered by nodes of other PANs while transmitting and receiving information.

In the N-CTAP period of the coordinated superframe, the nodes of different PANs simultaneously transmit and receive data frames; if the nodes of one PAN are exposed in the communication range of the nodes of another PAN, the data receiving process of the nodes of one PAN is possibly interfered by the data transmitted by the nodes of the other PAN; this problem can reduce the success rate of data frame reception, throughput and network bandwidth utilization, increase data frame delay, and is worth paying attention to and solving.

In the prior art: a reliable terahertz wireless personal area network MAC protocol [ J ] with high time slot utilization rate is an intelligent, strict, Zhou Haidong, Ku Yue Wei small-sized microcomputer system 2018(12), and provides a reliable terahertz wireless personal area network MAC protocol-RHSU-MAC with high time slot utilization rate aiming at the problems of time slot resource waste and unnecessary retransmission of frame aggregation caused by inherent physical properties of terahertz wireless communication; wangming, research [ D ] of routing protocol of ultrahigh-speed wireless personal area network, Chongqing post and telecommunications university, 2016, and proposes a data transmission mechanism of MINN-PAN, which mainly allocates a new mechanism for a time slot of a new network access node; but none avoid the problem of transmission interference.

Disclosure of Invention

The invention aims to solve the technical problem of how to efficiently and timely transmit the next superframe time slot allocation proportion information of a central controller PNC in one PAN network to the central controllers PNC of adjacent PAN networks in the current superframe, so as to avoid the interference caused by the edge nodes of different networks which are mutually in the communication range in the MP-THz-WPAN of omnidirectional communication when transmitting data; the time slot allocation schemes of adjacent PAN networks in the same coordinated superframe are coordinated, so that the condition of 'one-sending-one-receiving' between edge nodes of different PAN networks is avoided as much as possible, the interference brought by the edge nodes is reduced, and the data transmission performance is improved.

The technical scheme adopted by the invention is as follows:

a method for efficiently and adaptively transmitting time slot distribution proportion information across a PAN (personal area network) comprises the following steps:

(1) in the CAP period of the superframe, central controllers PNC in two adjacent PAN networks respectively calculate time slot allocation proportion information, write the calculated time slot allocation proportion information into a time slot request reply frame, and send the time slot request reply frame out;

(2) in the CAP period of a superframe, after nodes in two adjacent PAN networks receive a time slot request reply frame, judging whether the nodes are bridge nodes or edge nodes; if the node is a bridge node and a frame is to be sent in the current superframe, starting the operation of transmitting the time slot allocation proportion information by the node, and executing the step (3); if the node is an edge node and the gateway node does not send frames but sends frames in the current superframe, starting the operation of transmitting time slot allocation proportion information by the node, and executing the step (4);

(3) in the CAP period of the superframe, the bridge node extracts the time slot allocation proportion information in the time slot request reply frame and stores the time slot allocation proportion information of the PAN network with higher priority; in a CTAP period, the network bridge node writes the stored time slot allocation proportion information into each data frame or ACK frame to be sent, and then sends the data frame or ACK frame; in a CTAP period, the central controllers PNC in two adjacent PAN networks monitor channels, and when a data frame or an ACK frame which comes from a bridge node and has time slot distribution proportion information is monitored, the time slot distribution proportion information is extracted, and the monitoring is stopped; then the central controller PNC judges whether the extracted time slot allocation proportion information is the same as the self-stored time slot allocation proportion information; if the current time slot allocation proportion information is different from the current time slot allocation proportion information, adjusting the time slot allocation condition of the next superframe in the PAN according to the extracted information, and updating the stored time slot allocation proportion information;

(4) in the CAP period of a superframe, the edge node extracts the time slot allocation proportion information in the time slot request reply frame for storage; in the CTAP period of the superframe, before sending a data frame or an ACK frame, if an edge node receives frames sent by other edge nodes, extracting the time slot allocation proportion information and replacing the self-stored time slot allocation proportion information; before sending a frame, the edge node writes the stored time slot allocation proportion information into a data frame or an ACK frame to be sent, and then sends the data frame or the ACK frame; in a CTAP period of a superframe, a central controller PNC monitors a channel, and when a data frame or an ACK frame which comes from an edge node and has time slot distribution proportion information is monitored, the time slot distribution proportion information is extracted and compared with the time slot distribution proportion information stored by the central controller PNC; if the difference is not the same, the time slot distribution condition of the next superframe in the PAN is adjusted according to the extraction information, and the stored time slot distribution proportion information is updated.

The timeslot allocation proportion information refers to the proportion of 4 different types of timeslots in all allocated timeslots, the timeslot types are divided according to the difference between the source node and the destination node using the timeslot, and there are 4 types in total, specifically: the source and destination are both time slots of a common node; the source is a time slot of the common node and the destination is an edge node; the source is a time slot of the edge node and the destination is a common node; both the source and destination are time slots of the edge node.

Wherein, the proportion value in the time slot allocation proportion information is a decimal or integer belonging to the interval of [0,1 ]; dividing the [0,1] interval into 4 cells which are equal in length and 0.25 in length, and using 2bits to represent which cell the proportion value in the time slot allocation proportion information belongs to; the corresponding relation between the 2bits value and the cell is as follows: 00- (0, 0.25), 01- (0.25, 0.5), 10- (0.5, 0.75), 11- (0.75, 1).

Compared with the prior art, the invention has the advantages that:

in the multi-PAN terahertz wireless personal area network, the proportion information occupied by the communication type in the network is efficiently and timely transmitted to the PNC in another network under the condition of not increasing extra data overhead. Therefore, the PNC of the adjacent PAN can consciously avoid the collision of data frames during time slot allocation, thereby improving the success rate of data frame transmission, the network throughput and the utilization rate of channel bandwidth, and being beneficial to reducing the transmission delay of the data frames.

Drawings

Fig. 1 is a schematic diagram of a coordinated superframe structure;

FIG. 2 is a schematic diagram of node type partitioning;

FIG. 3 is a flow chart of a CTAP period PNC node processing in the PAN network of the present invention;

FIG. 4 is a flow chart of a CTAP period non-PNC node processing in the PAN network of the invention;

FIG. 5 is a diagram illustrating the structure of the Frame control field according to the present invention;

FIG. 6 is a diagram illustrating the structure of the Fragmentation control field in accordance with the present invention;

fig. 7 is a diagram illustrating the frame type reserved value according to the present invention.

Detailed Description

The invention is further explained below with reference to the drawings.

A method for transmitting time slot distribution proportion information across PAN with high efficiency and self-adaptation comprises the following three innovative mechanisms:

(1) a time slot allocation proportion information efficient carrying mechanism based on various frames.

(2) A unidirectional efficient transfer mechanism for information based on the timeslot allocation proportion of bridge nodes.

(3) And (3) an adaptive bidirectional efficient transfer mechanism based on the time slot allocation proportion information of the edge node.

The following describes the above 3 new mechanisms in detail.

Time slot distribution proportion information efficient carrying mechanism based on multiple frames

The main contents of the new mechanism of 'carrying time slot distribution proportion information based on various frames efficiently' are: slot allocation ratio information is transmitted from one node to another node (which may be a PNC, a gateway, an edge node, or a general node) in different cases with different types of frames including a slot request reply frame, a data frame, and an ACK frame without increasing control overhead (referring to the number of bits used for control). The ultimate purpose of transmitting the slot allocation ratio information between the nodes is to transmit the information from the PNC of one PAN to the PNC of the neighbor PAN.

The specific case of using three types of frames, the slot request reply frame, the data frame, and the ACK frame, is as follows:

(1) slot request reply frame: the time slot allocation proportion information is used when the time slot allocation proportion information is transmitted from the PNC to the gateway or from the PNC to the edge node.

(2) Data frame: the time slot allocation proportion information is used when the time slot allocation proportion information is transmitted from the gateway to the PNC, or from the edge node to the edge node, or from the edge node to the PNC.

(3) And ACK frame: the time slot allocation proportion information is used when the time slot allocation proportion information is transmitted from the gateway to the PNC, or from the edge node to the edge node, or from the edge node to the PNC.

If slot allocation proportion information is carried, the type value of the frame is set to a new value.

According to the difference between the source node and the destination node of the service, the invention divides the types of the time slots allocated to the nodes into the following 4 types:

(1) common node- > common node;

(2) common node- > edge node;

(3) edge node- > common node;

(4) edge node- > edge node.

The ratio of the number of slots of each type to the total number of slots can be divided into 4 cases: less than 1/4, 1/4-1/2,1/2-3/4, and greater than 3/4. The above-mentioned 4 types of time slot allocation proportions are one total of 4x4x4x4 to 256 cases. If a 2's number is used to convey the slot allocation fraction information, 8bits are required.

In the present invention, sufficient reserved bits and reserved values are found in the fields of the MAC frame headers (each frame includes a MAC frame header) to indicate the allocation ratio of the 4 types of timeslots, which is specifically as follows:

in the Frame control field of the MAC header, b11-b15 are reserved bits; in addition, the Protocol version default is 000, and the others are all reserved values, as shown in fig. 5. B23 in the Fragmentation control is a reserved bit, as shown in FIG. 6. A diagram of frame type retention values is shown in fig. 7.

In the reserved values and reserved bits, the last two bits in Protocol version are used for representing the proportion of the first type, namely from the common node to the common node; b11 and b12 in the Frame control are used for representing the proportion of the second type, namely from a common node to an edge node; b13 and b14 in the Frame control are used for representing the proportion of the third type, namely from the edge node to the common node; the proportion of the fourth type, i.e. edge node to edge node, is represented by b15 in the Frame control and b23 in the Frame control. Wherein 00 represents 1/4 or less, 01 represents 1/4 or more and 1/2 or less, 10 represents 1/2 or less and 3/4 or less, and 11 represents 3/4 or less and 1 or less.

(II) efficient unidirectional transmission mechanism of time slot proportion information based on bridge nodes

The main contents of the new mechanism of 'the unidirectional and efficient transmission of the time slot allocation proportion information based on the bridge nodes' are as follows: in the CTAP period of the superframe, if a bridge node is to send a frame (data frame or ACK frame), slot allocation proportion information is transmitted from the PNC of one PAN to the PNC of another PAN by the bridge node without increasing control overhead. The direction does not change during the transfer.

The time slot allocation proportion information transmitted by the bridge node is obtained by 'overhearing' the time slot request reply message in the CAP period.

The direction in which the bridge node transmits the slot allocation proportion information is designed as follows:

(1) if the bridge node receives slot allocation ratio information for two PANs in the CAP period (i.e. slot request reply messages are received in both PANs), the direction is determined according to the priority of the PANs: the transfer from the PNC of the high priority PAN to the PNC of the low priority PAN is recommended. The priority of the PAN may be determined by a preset method, such as the size of the ID of the PNC.

(2) If the bridge node receives slot allocation ratio information for only one PAN during the CAP period (i.e., a slot request reply message is received in only one PAN), the slot allocation ratio information is transmitted from the PAN that received the information to another PAN (i.e., a PAN that did not receive its slot allocation ratio information).

(3) If the bridge node does not receive the time slot allocation proportion information of any PAN in the CAP period, the bridge node does not transmit.

In order to guarantee successful transmission, it is recommended that all frames sent by the bridge node carry timeslot allocation proportion information.

(III) efficient on-demand transfer mechanism of time slot allocation proportion information based on edge nodes

When a bridge node is not framing in the CTAP period of the superframe, slot allocation proportion information needs to be transmitted by the edge node. Therefore, the invention provides a new mechanism of 'efficient and on-demand transmission of the time slot allocation proportion information based on the edge node', so that the edge node can transmit the time slot allocation proportion information as required.

The main contents of the new mechanism of 'efficient on-demand delivery of time slot allocation proportion information based on edge nodes' are: in the Beacon period of the superframe, the edge node judges whether the bridge node is to send a frame in the CTAP period of the current superframe according to the received Beacon frame; if yes, no subsequent operation is performed. If not, judging whether the frame is to be sent in the CTAP time period; if not, the subsequent operation is not carried out. If yes, the user participates in the transmission of the time slot allocation proportion information, and then requests a reply frame in the time slot of the CAP period of 'general listening' to acquire the time slot allocation proportion information of the PAN; then, when the frame is transmitted by itself in the CTAP period, slot allocation ratio information is carried in the frame.

In order to ensure the consistency of the transmission direction of the time slot allocation proportion information, the time slot allocation proportion information sent by the edge nodes in the same PAN is coordinated, and the edge nodes need to "overhear" frames sent by other edge nodes in the N-CTAP sub-period. If the edge node receives the time slot allocation proportion information carried in the frame sent by other edge nodes (no matter in the current PAN or the adjacent PAN) before sending the frame, the information is used for covering the stored time slot allocation proportion information. During the transfer, the direction may change.

If the PNC receives different time slot allocation proportion information carried by a plurality of edge nodes in the PAN, the later received information covers the earlier received information. If the time slot allocation proportion information sent by the bridge node is received, the information is taken as the final information, and then the 'overhearing' operation is stopped (namely, the time slot allocation proportion information carried by the received frame is stopped).

The invention adopts the thinking of 'limited PAN listening' (extracting useful information and then discarding for the frame carrying the useful information but not the destination, and carrying the information by using the reserved field or the reserved value (not increasing control overhead)), and adaptively transfers the time slot allocation proportion information of one PAN to another PAN in time and efficiently by means of the bridge nodes, a plurality of edge nodes or a single edge node:

the main idea is as follows:

1) both the network bridge node and the edge node participate in the transmission of the time slot allocation proportion information; according to different situations, the time slot allocation proportion information is adaptively transmitted across the PAN by the bridge node, a plurality of edge nodes or a single edge node.

2) When the PNC is transmitted through the bridge node, the direction is unidirectional and all the directions are from the PNC with high priority to the PNC with low priority; in this case, the PNC with the lower priority matches the PNC with the higher priority in the slot allocation order.

3) If the bridge node is to send a frame during the CTAP period, it is responsible for passing the slot proportion assignment information in the direction: high PNC- > low PNC; if the frame is not sent, the edge node is responsible for the delivery.

4) When the PNC is transmitted through the edge node, the direction is non-directional, and the PNC with high priority and the PNC with low priority or the other direction are possible, and the direction may be changed in the process of operation and is finally determined in a self-adaptive mode according to the operation condition.

The specific implementation process of the invention is as follows:

a method for efficiently and adaptively transmitting time slot distribution proportion information across a PAN (personal area network) comprises the following steps:

(one) Beacon time period

The operation of the Beacon time interval node is divided into two types: PNC; a non-PNC node.

PNC Main operation

The main operation of the Beacon period PNC is the same as that of the existing related protocol, and mainly includes:

(1) beacon frames are generated and assembled. (same as existing protocol)

(2) Broadcasting beacon frames. (same as existing protocol)

2. non-PNC node primary operation

The main operations of the nodes except PNC in Beacon period are as follows:

(1) and receiving the beacon frame and storing the time slot allocation information in the beacon frame. (same as existing protocol)

(2) And judging the node type of the self.

(3) If it is a normal node, the subsequent time operates in the usual manner.

(4) If the node is the edge node, judging according to the time slot allocation information: is it self-framing and is the bridge node not framing? If yes, determining that the subsequent time of the user needs to participate in the time slot allocation proportion information transmission; if not, the time slot allocation proportion information is determined not to be involved in the transmission, and the subsequent time is operated in a normal manner. And, information on whether or not it participates in (slot allocation ratio information) transmission is stored.

(5) If the network bridge node is the network bridge node, judging whether the beacon frame of the two PANs needs to be sent or not according to the time slot allocation information after the beacon frames of the two PANs are received; if yes, determining that the subsequent time of the user needs to participate in the time slot allocation proportion information transmission; if not, the time slot allocation proportion information is determined not to be involved in the transmission, and the subsequent time is operated in a normal manner. And, information on whether or not it participates in (slot allocation ratio information) transmission is stored.

(II) CAP period

The operation of the nodes in the CAP period is divided into two categories: PNC; a non-PNC node.

PNC Main operation

The main operation of the CAP period PNC is different from the operation method of the existing related protocol, and the operations of classifying and arranging the slot positions (normal- > normal, normal- > edge, edge- > normal, edge- > edge) and loading the slot allocation proportion information into the slot request reply frame are added. The operation of the PNC is mainly:

(1) and receiving the time slot request frame sent by other nodes. (same as existing protocol)

(2) After receiving the time slot request message, if the residual time slots are enough to be allocated, the time slots are agreed to be allocated to the application nodes, and the positions of the allocated time slots are arranged in a classified mode.

(3) Slot allocation proportion information is loaded into the slot request reply frame.

(4) And sending the time slot request reply frame to the application node. (same as existing protocol)

2. non-PNC node primary operation

The main operation of the non-PNC node in the CAP period is different from the operation method of the existing related protocol, and the operations of 'overhearing' as required, storing time slot distribution proportion information and the like are added. The operations of the non-PNC nodes are mainly as follows:

(1) judging whether the user needs to participate in the transmission of the time slot allocation proportion information; if yes, the PNC listens to the time slot request reply frame sent by the PNC, and extracts and stores time slot allocation proportion information from the frame; if not, the operation of 'over-listening' and the like is not carried out.

(2) Judging whether data need to be sent or not; if so, the required amount of time slots is calculated and a time slot request frame is generated and filled, and then transmitted to the PNC. (same as existing protocol)

(3) If a reply frame sent by the PNC is received, the content of the reply frame is extracted, and the time slot request result is stored.

(same as existing protocol)

(III) CTAP period

The operation of the CTAP period node is divided into two categories: PNC; a non-PNC node.

PNC Main operation

As shown in fig. 3, the main operation of the CTAP period PNC is different from the operation method of the existing related protocol, and operations such as "flooding" bridge node, edge node, and updating timeslot allocation ratio information are added. The operation of the PNC node mainly comprises the following steps:

(1) the PNC carries out 'flood listening' operation, and the PNC does not directly discard the data frame and the ACK frame after receiving the data frame and the ACK frame, but extracts the source node ID to judge whether the source node is an edge node or a bridge node.

(2) If the source node is an edge node, the PNC judges whether the frame carries time slot allocation proportion information or not according to the frame type; if carrying, extracting the information ratio and storing (if the time slot allocation ratio information is stored before and is different from the information received this time, covering the information received this time with the information received this time); after entering the P-CTAP sub-period, the PNC judges whether the received time slot allocation proportion information is the same as the self time slot allocation proportion information; if the time slot distribution proportion information is different, the time slot arrangement of the PAN is adjusted according to the received time slot distribution proportion information.

(3) If the source node is a bridge node, the PNC extracts and stores the time slot allocation proportion information from the frame; and stop the "overhearing" operation (i.e. stop receiving the timeslot allocation proportion information carried by the frame); then, PNC judges whether the received time slot allocation proportion information is the same as the self time slot allocation proportion information; if the time slot distribution proportion information is different, the time slot arrangement of the PAN is adjusted according to the received time slot distribution proportion information.

2. non-PNC node primary operation

As shown in fig. 4, the main operation of the non-PNC node in the CTAP period is different from the operation method of the existing related protocol, and operations of carrying, "overhearing" and storing timeslot allocation ratio information and the like are added according to needs. The operations of the non-PNC nodes are mainly as follows:

(1) the node judges the type of the node, which is the bridge node, the edge node or the common node.

(2) And if the node is the bridge node, judging whether to participate in the transmission of the time slot allocation proportion information according to the information stored in the Beacon time period. If so, slot allocation proportion information is carried in each frame transmitted. If not, then nothing is done during the CTAP period.

(3) And if the node is the edge node, judging whether to participate in the transmission of the time slot allocation proportion information according to the information stored in the Beacon time interval. If yes, carrying time slot distribution proportion information in the frame sent by the user; moreover, before sending out the frame by itself, the frame sent out by other edge nodes is 'overheard'; if the frame of the 'universal listening' carries the time slot allocation proportion information, extracting the information and covering the previously stored time slot allocation proportion information with the information; this flood listening and information updating operation stops after sending out a frame by itself.

If the node is a common node, the operation method is the same as the operation method specified by the existing related protocol, and mainly sends or receives frames in the time slot specified by the PNC, or does not do any operation.

The embodiment of the invention specifically comprises the following steps:

(1) in the CAP period of the superframe, central controllers PNC in two adjacent PAN networks respectively calculate time slot allocation proportion information, write the calculated time slot allocation proportion information into a time slot request reply frame, and send the time slot request reply frame out;

the timeslot allocation proportion information refers to the proportion of 4 different types of timeslots in all allocated timeslots, the timeslot types are divided according to the difference between the source node and the destination node using the timeslot, and there are 4 types in total, specifically: the source and destination are both time slots of a common node; the source is a time slot of the common node and the destination is an edge node; the source is a time slot of the edge node and the destination is a common node; the source and destination are both time slots of the edge node; the proportion value in the time slot allocation proportion information is a decimal or an integer belonging to the interval of [0,1 ]; dividing the [0,1] interval into 4 cells which are equal in length and 0.25 in length, and using 2bits to represent which cell the proportion value in the time slot allocation proportion information belongs to; the corresponding relation between the 2bits value and the cell is as follows: 00- (0, 0.25), 01- (0.25, 0.5), 10- (0.5, 0.75), 11- (0.75, 1).

(2) In the CAP period of a superframe, after nodes in two adjacent PAN networks receive a time slot request reply frame, judging whether the nodes are bridge nodes or edge nodes; if the node is a bridge node and a frame is to be sent in the current superframe, starting the operation of transmitting the time slot allocation proportion information by the node, and executing the step (3); if the node is an edge node and the gateway node does not send frames but sends frames in the current superframe, starting the operation of transmitting time slot allocation proportion information by the node, and executing the step (4);

(3) in the CAP period of the superframe, the bridge node extracts the time slot allocation proportion information in the time slot request reply frame and stores the time slot allocation proportion information of the PAN network with higher priority; in a CTAP period, the network bridge node writes the stored time slot allocation proportion information into each data frame or ACK frame to be sent, and then sends the data frame or ACK frame; in a CTAP period, the central controllers PNC in two adjacent PAN networks monitor channels, and when a data frame or an ACK frame which comes from a bridge node and has time slot distribution proportion information is monitored, the time slot distribution proportion information is extracted, and the monitoring is stopped; then the central controller PNC judges whether the extracted time slot allocation proportion information is the same as the self-stored time slot allocation proportion information; if the current time slot allocation proportion information is different from the current time slot allocation proportion information, adjusting the time slot allocation condition of the next superframe in the PAN according to the extracted information, and updating the stored time slot allocation proportion information;

(4) in the CAP period of a superframe, the edge node extracts the time slot allocation proportion information in the time slot request reply frame for storage; in the CTAP period of the superframe, before sending a data frame or an ACK frame, if an edge node receives frames sent by other edge nodes, extracting the time slot allocation proportion information and replacing the self-stored time slot allocation proportion information; before sending a frame, the edge node writes the stored time slot allocation proportion information into a data frame or an ACK frame to be sent, and then sends the data frame or the ACK frame; in a CTAP period of a superframe, a central controller PNC monitors a channel, and when a data frame or an ACK frame which comes from an edge node and has time slot distribution proportion information is monitored, the time slot distribution proportion information is extracted and compared with the time slot distribution proportion information stored by the central controller PNC; if the difference is not the same, the time slot distribution condition of the next superframe in the PAN is adjusted according to the extraction information, and the stored time slot distribution proportion information is updated.