CN113766602A

CN113766602A - Networking method of wireless network and wireless network structure

Info

Publication number: CN113766602A
Application number: CN202010499001.0A
Authority: CN
Inventors: 杨浩
Original assignee: Beijing Nufront Mobile Multimedia Technology Co Ltd
Current assignee: Beijing Nufront Mobile Multimedia Technology Co Ltd
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2021-12-07

Abstract

The invention provides a networking method and a wireless network structure of a wireless network, wherein the networking method comprises the following steps: the network main node searches to obtain one or two sub-nodes and establishes wireless connection with the sub-nodes; the child nodes continue to search to obtain one or two grandchild nodes, and the child nodes and the grandchild nodes are in wireless connection; the grandchild node continues searching to obtain one or two subsequent nodes, and wireless connection is established between the grandchild node and the subsequent nodes; thus, the nodes in the predetermined area are connected together step by step to form a wireless network with a tree structure. The invention adopts limited connection topology, and avoids the possibility of repeated connection and data oscillation of the traditional network topology. The method has the same space coverage capability, can adapt to omnidirectional networking arrangement, and is easy to manage. The topological structure is more economical in utilization of frequency spectrum resources, and the algorithm design is simpler, so that the design cost and power consumption of node hardware are reduced.

Description

Networking method of wireless network and wireless network structure

Technical Field

The present invention belongs to the field of wireless communication technologies, and in particular, to a networking method for a wireless network and a wireless network structure.

Background

A wireless Mesh network, i.e. "wireless Mesh network", is a wireless multi-hop (multi-hop) network. The wireless Mesh network is a novel network structure based on multi-hop routing and peer-to-peer network technology, has the advantages of high broadband speed and high spectrum efficiency through mutual cooperation among a plurality of wireless access points distributed in a Mesh shape, and has the outstanding characteristics of dynamic ad hoc network, self management, self maintenance and the like.

The arrival of the 5G era covers eMBB, URLLC and eMTC services of communication, wherein the application of the Internet of things is well-blown. The wireless Mesh network is a high-reliability wide-coverage WLAN network, is a wireless area network solution suitable for covering large-area open districts (including outdoor and indoor), and has good adaptability, network reliability, self-configuration capability and flexible networking, so that the wireless Mesh network is widely applied to the Internet of things such as intelligent transportation, Internet of vehicles and the like.

As shown in fig. 1, each node in the conventional mesh network topology is a relay node, and all or more than 2 nodes and less than a certain number of nodes around the node are fully connected to implement network coverage on a place to be arranged. The disadvantages are as follows: the nodes are in a full-connection mode, and invalid and repeated connection is inevitable, so that the network efficiency is low, data transmission oscillation is generated, the requirement on a routing management technology is high, and a complex logic circuit design is required.

Aiming at the problems of low network efficiency and the like in the prior art, the network structure needs to be optimized and improved.

Disclosure of Invention

In view of this, the technical problem to be solved by the present invention is to provide a wireless network with a low power consumption and a novel topology structure, so as to meet the requirements of customers on a low power consumption internet of things, and as a supplement to the existing internet of things, the wireless network truly covers three scenes of 5G, and becomes a powerful competitor of 3 GPP. And the networking process of the equipment of the Internet of things needs an ad hoc networking technology without base station intervention, so that the networking capability and the environmental adaptability are enhanced.

The embodiment of the invention provides a networking method of a wireless network, which comprises the following steps:

the network server (network initial master node) initiates a connection and initiates a sub-node search through a dedicated channel.

The network main node searches to obtain one or two sub-nodes and establishes wireless connection with the sub-nodes;

the special channel is used for establishing a networking process, when the number of the main node connected with the sub-nodes is less than 2, the main node sends out an interception signal in the special channel at regular time, and the nearby terminals receive the interception signal and become the sub-nodes of the main node through the response signal terminals.

The child nodes continue to search to obtain one or two grandchild nodes, and the child nodes are wirelessly connected with the grandchild nodes;

the grandchild node continues searching to obtain one or two subsequent nodes, and wireless connection is established between the grandchild node and the subsequent nodes; thus, the nodes in the predetermined area are connected together step by step to form a wireless network with a tree structure.

Preferably, each node performs the search, specifically including:

and sending a Search frame (Search) within a preset time period, receiving acknowledgement signals ACK fed back by other nodes, and selecting two nodes from the Search frame as child nodes according to the strength of each received acknowledgement signal ACK.

Wherein the Search frame (Search) includes:

preamble (Preamble), frame type bit (ordertype), terminal ID number (sourceID) transmitting the frame, transmit power (gain), time information for transmitting the frame, channel information (chID), and integrity verification bit.

Preferably, the networking method further includes:

each node in the wireless network forming the tree structure allocates a time slot with a preset time length, so that each node performs data transmission. Particularly, when the identities of the father node and the child node are changed, the time division switching is completed by using different time slots of a communication cycle, and the data is transmitted in a pipeline manner in the network. The corresponding time slots are called uplink time slot and downlink time slot.

The invention provides a wireless network which comprises a main node, a plurality of child nodes and a grandchild node, wherein the main node is in wireless connection with one or two child nodes; the child nodes establish wireless connection with one or two grandchild nodes; the grandchild node establishes wireless connection with one or two subsequent nodes; the nodes which establish the connection step by step form a wireless network with a tree structure.

During data communication, each child node can transmit and receive data with the father node, and the father node can forward communication between the two child nodes, so that the reachable mesh network characteristic of each node of the network is achieved. Each data frame contains transmission data and a series of binary routing codes. And each node correspondingly forwards data according to the lowest bit of the binary routing code, the binary routing code is shifted at the node after being forwarded, the number of bits of the routing code is reduced by 1 every time the routing code is transmitted, and the routing code is just emptied when the routing code reaches a destination. Each node is treated as a binary unit, and the high and low of the 1-bit routing code represents the choice of the divergent path. Whether the child node transmits data to the parent node or the parent node transmits data to the child node, the specified high-low order routing rule is obeyed. For example, when a parent node generates a child node, the child nodes are numbered as child node 0 and child node 1 according to the access sequence, so that when the parent node transmits data to the child node, the lowest bit of the routing code is 0, and the parent node transmits the data to the child node 0 when a downlink time slot arrives; otherwise, the parent node sends the data to the child node 1. When a child node transmits data to a father node and the father node needs to forward the data, the default father node transmits a low routing code bit to an upper layer and transmits a high routing code bit to another child node.

The beneficial effects obtained by the invention are as follows:

1. the scheme adopts a limited connection topology, and avoids the possibility of repeated connection and data oscillation of the traditional Mesh network topology.

2. The binary tree network topology in the application has the same space coverage capacity as the traditional Mesh network, can adapt to omnidirectional networking arrangement, and is easier to manage in connection logic of the binary tree.

3. The Mesh topological structure of the scheme is more economical in utilization of frequency spectrum resources, and the algorithm design is simpler, so that the design cost and the power consumption of node hardware are reduced, and the design requirements of extremely low power consumption and extremely low cost are met.

4. The time slot design of the scheme can provide flexible communication interval arrangement and is suitable for the compromise consideration of the application scene on the data size and the low power consumption of the terminal.

For the purposes of the foregoing and related ends, the one or more embodiments include the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects and are indicative of but a few of the various ways in which the principles of the various embodiments may be employed. Other benefits and novel features will become apparent from the following detailed description when considered in conjunction with the drawings and the disclosed embodiments are intended to include all such aspects and their equivalents.

Drawings

Fig. 1 is a schematic diagram of a conventional Mesh network topology provided by the present invention;

fig. 2 is a flow chart of a wireless network networking method provided by the present invention;

fig. 3 is a flowchart of a wireless network networking method according to an embodiment of the present invention

Fig. 4 is a schematic diagram of a wireless network architecture according to an embodiment of the present invention;

fig. 5a and 5b are schematic diagrams illustrating timing distribution of a wireless network networking process according to the present invention;

fig. 6 is a schematic diagram of data transmission in a wireless network according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a connection state that may be formed by a wireless networking according to an embodiment of the present invention.

Detailed Description

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of embodiments of the invention encompasses the full ambit of the claims, as well as all available equivalents of the claims. Embodiments of the invention may be referred to herein, individually or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed.

As shown in fig. 2, the networking method of a wireless network of the present invention includes:

s201, a network main node searches to obtain one or two sub-nodes and establishes wireless connection with the sub-nodes;

s202, the child nodes continue to search to obtain one or two grandchild nodes, and the child nodes and the grandchild nodes establish wireless connection;

s203, the grandchild node continues to search to obtain one or two subsequent nodes, and wireless connection is established between the grandchild node and the subsequent nodes; thus, the nodes in the predetermined area are connected together step by step to form a wireless network with a tree structure.

Searching by each node specifically comprises the following steps:

In a particular embodiment, the Search frame (Search) generally comprises:

The networking method of the wireless network further comprises the following steps:

each node in the wireless network forming the tree structure allocates a time slot with a preset time length, so that each node performs data transmission.

As shown in fig. 3, the wireless networking method provided in the embodiment of the present invention includes:

s301, a network main node (usually a network device, such as a network server) initiates networking and connects to a child node (such as a mobile terminal), and the network main node serves as a parent node and establishes a connection link with one or two child nodes;

specifically, a dedicated channel is set for establishing connection between a network main node and a nearby node, the dedicated channel is used for establishing a networking process, a network server initiates networking and searches for a nearby mobile terminal (child node); the network main node sends an interception signal through the special channel and establishes communication connection with a nearby mobile terminal (sub-node);

specifically, the network master node sends an interception signal through the dedicated channel, and the nearby terminals (child nodes) are all terminals that can receive the interception signal;

s302, the nearby sub-nodes receive the interception signal and send response signals to the network main node through the special channel;

the reply signal includes the ID number of the child node.

S303, the network main node receives a response signal sent by a nearby terminal in a pre-allocated time period, and selects a sub-node according to the signal intensity of the response signal; selecting two terminals with the strongest signal intensity as child nodes;

each node has one and only one parent node and each node has no more than two child nodes.

S304, the network main node serves as a father node and sends a confirmation signal to the selected child node;

the acknowledgement signal includes the ID number of the child node terminal.

S305, the selected child node receives the confirmation signal to confirm that the selected child node is the child node of the network master node.

And the child nodes serve as parent nodes and continue to be networked.

The whole network is networked in a tree structure.

It should be noted that each terminal has one and only one parent node, and each terminal as a parent node derives at most two transmission paths, and has no more than two child nodes.

For each node, it is both a child and possibly a parent. As shown in fig. 4, the node 3 is a child node of the node 2, the node 3 is a parent node for networking, and the node 3 has two child nodes: node 4 and node 5; the nodes 6 and 8 are only used as child nodes of the upper level and are not father nodes.

Fig. 5a and 5b are schematic diagrams illustrating timing sequence allocation of a wireless network networking process provided by the present invention, which show a search connection process of an ad hoc network.

As shown in fig. 5a, the communication time of each node is a periodic communication schedule, where the period is a pre-allocated time duration, and each period has three communication window times, which are time windows scheduled for three communication targets of the parent node, the primary child node, and the secondary child node. The time interval is arranged to ensure that adjacent nodes on the network do not have the problem of mutual channel interference.

As shown in fig. 5a, when the child node is first searched as a parent node, two child nodes are obtained, and then time windows of the primary child node and the secondary child node are directly arranged, and a normal communication mode is entered. As shown in fig. 5b, in the time window which is the parent node for the first time, only ACK of a word node is obtained, and then a Search frame (Search frame) is initiated in the next node period of each period for searching.

And (3) searching: the parent node uses the dedicated channel for a selected time window. For example, CH3 is used in one embodiment of the invention. There are only three channels available to each node, and the Search channel is a channel common to all nodes with the setting of CH 3. After the nodes establish communication, the communication channel used is switched between CH1 and CH2, for example, in the same period, a node uses CH1 for communicating with its parent node, and the node uses CH2 for communicating with its child node. On the other hand, if the communication with the parent node is CH2, the communication with the child node is CH 1. The specific selection is set when the communication network is established from the root node and is arranged through a networking process. Send out Search frame, the frame format is as follows:

preamble represents a Preamble sequence, ordertype represents a frame type (here, a Search type code), sourceID represents a terminal ID number for sending the frame, Gainlevel represents a current sending power level, time represents a current timing time (represented by a period counting number) for sending the frame, ch represents channel coding (corresponding to carrier setting of a radio frequency front end), and MIC is an integrity verification 4-bit word.

Ordertype description table is as follows:

ordertype	function(s)
		000	Search frame format
001	ACK frame format
		010	Sondata child node transmission frame
011	Data frame format
		100	REF
101	REF
		110	REF
111	REF

There are three outcomes after the Search frame is sent out: (1) no ACK signal; (2) only 1 ACK signal; (3) there are 2 or more ACK signals.

And for the child nodes capable of receiving the Search frame, the child nodes are always in the rx open state after being powered on, and the Search signal is intercepted. Upon receipt of the Search signal, rx is turned off and a random number between 1 and 5 is locally generated as the time window number for which an ACK is sent. Its transmission time point is one of 5 time windows. The ACK frame is sent by using the ch3 channel, and the structure of the ACK frame is as follows:

in the above frame structure, ordertype is ACK code, targetID represents ID of a parent node, sourceID represents ID of the child node, RSSI represents strength of a Search signal received by the child node, and MIC represents a signal integrity check word.

The parent node turns on RX after sending Search for a window length of 5 ACKs to receive.

In case 1, when the parent node initiates the Search process for the first time, the parent node still does not receive the ACK signal until initiating three rounds of Search processes, the Search process is ended, and the Search process is started again when the next cycle time window comes, but the Search process is not repeatedly initiated at this time.

In case 2, only one ACK signal is received, the parent node turns off RX, turns on the channel (ch1/ch2 channel) that TX represents using the given ch code in Search, and sends the global setting data transmitted from the parent node of the parent node to the master and child nodes, which is called the Sondata frame:

wherein, ordertype is Sondata type, targetID is child node ID, sourceID is father node ID, Time is current Time count value, ch is channel for specifying next period child node to communicate with current father node, starttime represents Time offset for next starting communication, period represents period for setting next communication, and apend represents continuous identification. server data is global setting data transmitted from the server, and MIC represents a signal integrity verification word.

Thereafter, the parent node initiates the Search process again after 1/2 cycles. And if the ACK is obtained, adding the node as a secondary child node, otherwise, initiating a Search process in the time window in each period later. The network can conveniently join the nodes at any time, and the branch structure is fully utilized for networking.

In case 3, the father node determines the first two terminal nodes with large RSSI values as the primary and secondary child nodes according to the RSSI value of the received ACK signal. And immediately sends Sondata to the master child node. After a half period, the secondary child node time window is opened to send Sondata to the secondary child node. Thus, communication is performed periodically.

Fig. 6 is a schematic diagram of data transmission in a wireless network according to an embodiment of the present invention.

After all network nodes establish connection links, a communication process (and data transmission) is performed, which is as follows with reference to fig. 6:

for any terminal which performs data transmission, the terminal can only transmit or receive through one channel at the same time, namely the terminal only serves as a transmitting end or a receiving end at the same time, and point-to-point data transmission is realized;

only starting and using two channels to transmit data at the same time; the two channels are a first channel CH1 and a second channel CH 2;

further, at the same time, any two adjacent point-to-point connections use different channels, and the two point-to-point connections are communication between two terminals; and at different time, the two terminals establish point-to-point connection to alternately use the first channel and the second channel. Specifically, as shown in fig. 6, there are 5 terminals in the system, and at time T1, terminal 1 and terminal 2 perform data transmission through a channel CH 1; terminals 2 and 3 do not communicate; terminal 3 and terminal 4 perform data transmission through channel CH 2; the terminal 4 and the terminal 5 do not communicate; at the same time, the connection established between terminal 1 and terminal 2 and the connection established between terminal 3 and terminal 4 are adjacent point-to-point connections, and the adjacent point-to-point connections use different channels for communication, so as to avoid possible channel interference.

At time T2, terminal 1 and terminal 2 do not communicate; terminals 2 and 3 perform data transmission through a channel CH 1; the terminal 3 and the terminal 4 do not communicate; terminal 4 and terminal 5 perform data transmission through channel CH 2;

at time T3, terminal 1 and terminal 2 perform data transmission through channel CH 2; terminals 2 and 3 do not communicate; terminal 3 and terminal 4 perform data transmission through channel CH 1; the terminal 4 and the terminal 5 do not communicate;

at time T4, terminal 1 and terminal 2 do not communicate; terminals 2 and 3 perform data transmission through a channel CH 2; the terminal 3 and the terminal 4 do not communicate; terminal 4 and terminal 5 perform data transmission through channel CH 1;

taking the communication between the terminal 1 and the terminal 2 as an example, at time T1, the terminal 1 and the terminal 2 perform data transmission through a channel CH 1; at time T2, terminal 1 and terminal 2 do not communicate; at time T3, terminal 1 and terminal 2 perform data transmission through channel CH 2; at time T4, terminal 1 and terminal 2 do not communicate; at time T5, terminal 1 and terminal 2 perform data transmission through channel CH 1; the point-to-point communication connections of the two terminals use the first channel and the second channel alternately at different times.

It should be noted that the data transmitted from the network server to the last child node needs to be relayed by the intermediate parent node.

The invention provides a wireless network, which comprises a main node, a plurality of child nodes and grandchild nodes;

the main node establishes wireless connection with one or two sub-nodes;

the child node establishes wireless connection with the one or two grandchild nodes;

the grandchild node establishes wireless connection with one or two subsequent nodes;

the nodes which establish the connection step by step form a wireless network with a tree structure.

Fig. 7 is a schematic diagram of a network topology that may be formed by a wireless network according to an embodiment of the present invention.

According to the technical scheme provided by the invention, the logic settings of the father node and the son nodes are increased, the transmission status of each node is defined, the network can automatically grow into a wireless network covering all the nodes in a binary tree networking mode, the automatic networking arrangement advantage is achieved, the limited connection topology avoids invalid and repeated connection, and meanwhile, the omnidirectional networking is realized; the point-to-point data transmission in the communication process is suitable for occasions with low requirement on communication time length and high requirement on hardware cost.

Compared with the scheme in the prior art, the invention has the following advantages:

1. the invention adopts limited connection topology, and avoids the possibility of repeated connection and data oscillation of the traditional Mesh network topology.

2. The binary tree network topology has the same space coverage capability as the traditional Mesh network, can adapt to omnidirectional networking arrangement, and has easier management of the connection logic of the binary tree.

3. The network topology structure provided by the invention saves more spectrum resources, has simpler algorithm design, and reduces the design cost and power consumption of node hardware, thereby meeting the design requirements of extremely low power consumption and extremely low cost.

Those of skill in the art will understand that the various exemplary method steps and apparatus elements described in connection with the embodiments disclosed herein can be implemented as electronic hardware, software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative steps and elements have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The steps of a method described in connection with the embodiments disclosed above may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a subscriber station. In the alternative, the processor and the storage medium may reside as discrete components in a subscriber station.

The disclosed embodiments are provided to enable those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the scope or spirit of the invention. The above-described embodiments are merely preferred embodiments of the present invention, which should not be construed as limiting the invention, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A networking method for a wireless network, comprising:

2. The networking method according to claim 1, wherein the searching by each node specifically includes:

3. The networking method of claim 1, wherein the Search frame (Search) comprises:

4. The networking method of claim 1, further comprising:

5. A wireless network comprises a main node, a plurality of sub-nodes and a grand node, and is characterized in that,

the main node establishes wireless connection with one or two sub-nodes;