CN113923748B

CN113923748B - Method for forming cluster network based on proxy change

Info

Publication number: CN113923748B
Application number: CN202111340154.1A
Authority: CN
Inventors: 刘桔; 穆鹏成; 陶功平
Original assignee: Chongqing University of Post and Telecommunications
Current assignee: Chongqing University of Post and Telecommunications
Priority date: 2021-11-12
Filing date: 2021-11-12
Publication date: 2023-06-02
Anticipated expiration: 2041-11-12
Also published as: CN113923748A

Abstract

The invention relates to a method for forming a cluster network based on proxy change, belonging to the technical field of wireless communication. The method comprises the following steps: s1: the CCO forms the entire network topology and establishes an initial route; s2: the station establishes an initial route; s3: the site actively initiates an agent change request message; s4: the CCO receives the proxy change request message, updates network topology and routing information, and constructs a proxy change confirmation message; s5: and the station receives the proxy change confirmation message and updates the route information. The invention reduces own hierarchy by the method of agent change to form a cluster network, so that the network topology is more compact, thereby reducing the number of relay stations required when information is acquired for the stations, reducing time expenditure and the number of downlink messages and improving the acquisition efficiency.

Description

Method for forming cluster network based on proxy change

Technical Field

The invention belongs to the technical field of wireless communication, and relates to a method for forming a cluster network based on proxy change.

Background

The intelligent meter reading technology in the user electricity consumption information acquisition system comprises a limited network and a wireless network, the wiring and line changing engineering quantity of the wired network is large, the broadband is continuously increased, the line becomes thicker and thicker, the entity line is easy to damage, the whole line has to be replaced by an error, and the maintenance is difficult. The wireless transmission networking avoids the difficulty of wiring, is simpler to maintain, is more flexible to networking, and improves the self-organization of the network. Therefore, the system adopts a wireless transmission mode.

In order to realize a user electricity consumption information acquisition system and rapidly acquire, process and monitor the electricity consumption information of an electric power user in real time, the agent site in the whole network is reduced through agent change after the electricity meter networking is completed, so that the transmission of messages is reduced, and the electricity consumption information acquisition efficiency of the user is improved. The user electricity consumption information acquisition system mainly comprises a main station, a local communication system and a communication network connected with each device, and is a basis for realizing the electricity consumption information acquisition of the user. The main station and the concentrator transmit data through a GPRS/CDMA wireless public network or an optical fiber private network, so that user electricity information is obtained, and the information is stored and analyzed; the local communication system mainly comprises a concentrator, an electric energy meter and a bidirectional communication network of the local communication system. The concentrator collects the data of the electric energy meter and reports the data to the main station.

The local communication system is typically tree-like as shown in fig. 1 or mesh-like as shown in fig. 2. Each of which comprises a concentrator, a plurality of electric energy meters and a communication module. The electric energy meter can be used as a Site (STA) or a Proxy Coordinator (PCO) of a communication network by arranging the communication module in the electric energy meter, and the Central Coordinator (CCO) of the communication network by arranging the communication module in the concentrator. In the process of collecting the electricity consumption of a user, a concentrator is responsible for starting an information collection service and sending information collection items, a PCO is responsible for receiving and forwarding a meter reading command of the CCO, actively acquiring and reporting own data to the CCO, and an STA is responsible for acquiring and sending the data to the corresponding PCO and sequentially forwarding the data to the CCO by the PCO.

As shown in fig. 1 and 2, the local communication system network includes a CCO and a plurality of STAs. When the STA starts to access the network, the STA is directly connected to the CCO, namely, the STA and the CCO directly communicate, and as other STAs access the network, the current STA changes the role of the current STA into PCO, namely, the current STA is used as a relay station for the other STA to communicate with the CCO. If the current station is PCO, all the STAs connected below the current station are disconnected at the moment, and the role of the current station is changed from PCO to STA. The roles of PCO and STA are mutually convertible due to the randomness of the network topology changes. Each electric energy meter has a unique identifier (TEI) for distinguishing, and the information acquisition message initiated by the concentrator is also routed by searching the TEI.

Each communication module specifically comprises an application layer (APP layer for short), a DATA link layer (DATA layer for short) and a physical layer (PHY layer for short), wherein the DATA link layer is divided into an NWK layer and a MAC layer. When a meter reading command frame is transmitted, the transmission direction of the data is shown in fig. 3.

If the TEI of the CCO is set to 1 in fig. 1, the TEI of other sites is as follows, and if the TEI is set to 8 sites, the analysis and forwarding from the CCO to the PCO with TEI of 2 are needed, and after receiving the meter reading message, the STA with TEI of 8 stores, constructs and sends the meter reading response message. Similarly, the meter reading response message also needs PCO with TEI of 2 to help forward, so the PCO can also be called a relay station. According to fig. 3, each meter reading message passes through one PCO station at any time when transmitted, the PHY layer is required to receive the DATA layer for processing and forwarding, and the meter reading message is issued and responded according to the original path, which wastes time and consumes resources. In an actual scene, the communication quality between the site with the TEI of 8 and the CCO is good, and only the site with the TEI of 8 receives interference when entering the network, so that the site with the TEI of 2 is selected as a relay site of the site, and the problems of waste of air interface transmission, long acquisition period and low efficiency are caused when the site is subjected to meter reading.

Disclosure of Invention

Therefore, an object of the present invention is to provide a method for forming a cluster network based on proxy modification, which uses a specific field in a beacon frame to receive beacon frame synchronization time slot information in TDMA time slots after a node accesses the network, and estimates time slot information of the next cycle in CSMA time slots according to time slot parameters of the present cycle. And when the next period is entered, if the beacon frame is received in the TDMA time slot, the estimated time slot information of the previous period is erased, and the time slot information carried in the beacon frame is used for synchronization. If the beacon frame is not received in the TDMA time slot because of network abnormality, using the time slot estimation information of the last period, temporarily maintaining the network by sending a discovery list message in the estimated CSMA time slot, waiting for abnormality relief or entering an offline flow.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a method of forming a clustered network based on proxy modification, the method comprising the steps of:

s1: the CCO forms the entire network topology and establishes an initial route;

s2: the station establishes an initial route;

s3: the site actively initiates an agent change request message;

s4: the CCO receives the proxy change request message, updates network topology and routing information, and constructs a proxy change confirmation message;

s5: and the station receives the proxy change confirmation message and updates the route information.

Optionally, the S1 specifically is:

s11: after CCO is electrified, the MAC address is acquired, a white list is configured, a beacon frame and a network notification message are broadcast, and the receiving station requests to access the network message is started to wait;

s12: after receiving a request network access message of a station, the CCO verifies whether the MAC address of the station is in a white list; if the white list allows network access, a unique TEI number is allocated to a station and a beacon time slot of the station is arranged, initial route information is analyzed and stored, a network success confirmation message is constructed and sent, and otherwise, a network failure confirmation message is constructed and sent;

s13: after the station is accessed to the network, the CCO starts to perform network maintenance and sends a network maintenance message to surrounding stations.

Optionally, the S12 specifically is:

s21: after the station is electrified, acquiring an MAC address, monitoring surrounding signals, analyzing and storing information after receiving a network notification message and a beacon frame, ending the monitoring time, constructing a network access request message, and waiting for receiving a network access confirmation message;

s22: after receiving a successful network access confirmation message sent by the CCO, the station analyzes and stores the TEI number and initial routing information carried in the message, and sends a discovery beacon frame in a scheduled beacon time slot, otherwise, after receiving a network access failure message sent by the CCO, the station gives up the network and continues to monitor and search for a new network to attempt network access;

s23: after the station is accessed to the network, the routing information and the TEI number are stored in a network maintenance message, and a discovery beacon frame and the network maintenance message are sent to surrounding stations.

Optionally, the S3 specifically is:

s31: the station periodically receives network maintenance messages sent by surrounding stations, analyzes TEI numbers, routing information, SNR values and connected sub-station numbers in the network maintenance messages, and stores the network maintenance messages to form a local network topology map;

s32: when the cycle time is up, the station traverses the local network topological graph, whether the path has fewer hops than the current path or not, if so, the station jumps to S33, and if not, the station jumps to S36;

s33: the station checks whether the SNR value of the selected path is larger than or equal to a threshold value, if so, the station stores the path information and jumps to S34, otherwise, jumps to S36;

s34: the stored path information is ranked according to the fact that the number of route hops is small, if the number of route hops is the same, the stored path information is ranked according to the number of sub-stations connected with the station, and if the number of sub-stations connected with the station is the same, the stored path information is ranked according to the variance of the SNR;

s35: the station selects an optimal path from the ordered paths, constructs and sends a proxy change request message;

s36: when the cycle time is up, the received network maintenance message is cleared, and the process jumps to S2 to restart the receiving;

the fields of the network maintenance message include: total hop count from station TEI of 12 bits to CCO of 4 bits, (path station TEI of the station of 12 bits+path station SNR of 4 bits) N, broadcasting period of 8 bits, number of connected sub-stations of 8 bits, N is total hop count;

the default TEI of the CCO is 1, and the TEIs of other stations are uniformly distributed by the CCO and are unique and non-repeatable in the network; the broadcasting period defaults to 2 routing periods and can be modified; the hop count indicates the number of relay stations which need to pass from the CCO to the destination station, and the number of sub stations indicates the number of sub stations connected with the station;

the storage space occupied by each station in the station storage routing table information structure is 4+2 x N bytes, each entry stores one route, the number of route paths passing through the transit station is 14 at most, wherein the first route is a main route, and the other routes are new routes collected;

after 2 routing cycles are completed, the station sorts the routing table.

Optionally, the S4 specifically is:

s41: the CCO receives the agent change request initiated by the site, stores and analyzes 5 agent sites carried in the message, judges whether to allow agent change according to whether the 5 selected sites are online, jumps to S42 if the agent change is allowed, and jumps to S44 if the agent change is not allowed;

s42: distributing new proxy sites according to the number of sub-sites connected under each site, wherein the more the number of sub-sites is, the more the sub-sites are distributed to the sites with proxy changes as new sites;

s43: updating the routing table information, constructing an agent change confirmation message, filling 1 in a result field, and jumping to S45;

s44: constructing an agent change confirmation message and filling 0 in a result field;

s45: and sending a proxy change confirmation message.

Optionally, the step S5 specifically includes:

s51: the station receives the agent change confirming message, analyzes the message field, judges whether the result in the message is allowed change, and jumps to S52 if the result in the message is allowed change, otherwise jumps to S53;

s52: analyzing and storing path information;

s53: and releasing the message.

The invention has the beneficial effects that:

first: at present, the method for collecting the electricity consumption of the electric power user is mainly point-to-point polling collection, the collection mode can only read one electric meter at a time, the larger the site level is, the more the number of hops is, the more the transfer sites needed by meter reading are, the longer the consumed time is, and the collection period is longer. The invention reduces own hierarchy by the method of agent change to form a cluster network, so that the network topology is more compact, thereby reducing the number of relay stations required when information is acquired for the stations, reducing time expenditure and the number of downlink messages and improving the acquisition efficiency.

Second,: the invention provides a real basis for the information collection of the power users by adopting a rapid meter reading method, the rapid meter reading method sends a meter reading command to the PCO for the CCO, the PCO sends the meter reading command to the sub-station below the PCO, the sub-station collects and reports the meter reading command to the PCO by itself, and the PCO is summarized and forwarded to the CCO, so that the meter reading command only needs to be forwarded by the CCO and the PCO of the whole network. The station uses agent changing method to reduce PCO, and the sub station under each PCO is increased, thereby reducing the transmission quantity of message and the data congestion of air interface.

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 objects and other advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.

Drawings

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in the following preferred detail with reference to the accompanying drawings, in which:

FIG. 1 is a tree network topology;

FIG. 2 is a mesh network topology;

FIG. 3 is a diagram illustrating the data acquisition and transmission direction;

FIG. 4 is a station store routing table information structure;

FIG. 5 is a site store ordering table structure;

FIG. 6 is a method of ordering a station selection path;

fig. 7 is a schematic diagram of a wireless network topology upon completion of networking in accordance with an embodiment of the present invention;

FIG. 8 is a flow chart of a CO route establishment process in an embodiment of the present invention;

fig. 9 is a flow chart of a route setup process for a station according to an embodiment of the present invention;

FIG. 10 is a flow chart of a station-initiated proxy-change request in accordance with an embodiment of the present invention;

FIG. 11 is a flow chart of a CCO receiving a proxy change request in accordance with an embodiment of the present invention;

FIG. 12 is a flow chart of a station receiving agent change acknowledgement in accordance with an embodiment of the present invention;

fig. 13 is a network topology diagram of a site agent and formed later in an embodiment of the present invention.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the illustrations provided in the following embodiments merely illustrate the basic idea of the present invention by way of illustration, and the following embodiments and features in the embodiments may be combined with each other without conflict.

Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to limit the invention; for the purpose of better illustrating embodiments of the invention, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated 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 numbers in the drawings of embodiments of the invention correspond to the same or similar components; in the description of the present invention, it should be understood that, if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc., that indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but not for indicating or suggesting that the referred device or element must have a specific azimuth, be constructed and operated in a specific azimuth, so that the terms describing the positional relationship in the drawings are merely for exemplary illustration and should not be construed as limiting the present invention, and that the specific meaning of the above terms may be understood by those of ordinary skill in the art according to the specific circumstances.

The technical scheme of the invention comprises the following steps:

s1: the CCO forms the entire network topology and establishes an initial route;

s2: the station establishes an initial route;

s3: the site actively initiates an agent change request message;

The S1 specifically comprises the following steps:

s12: after receiving the request network access message of the station, the CCO verifies whether the MAC address of the station is in the white list. If the white list allows network access, a unique TEI number is allocated to a station and a beacon time slot of the station is arranged, initial route information is analyzed and stored, a network success confirmation message is constructed and sent, and otherwise, a network failure confirmation message is constructed and sent;

The step S2 is specifically as follows:

The step S3 is specifically as follows:

s35: the station selects an optimal path from the ordered paths, constructs and transmits a proxy change request message.

S36: and when the cycle time is up, the received network maintenance message is cleared, and the process jumps to S2 to restart the receiving.

The fields of the network maintenance message include: total hops of 12bit site TEI, 4bit site to CCO (abbreviated N), (12 bit path site tei+4bit path site SNR) N, 8bit broadcast period, 8bit number of connected sub-sites;

the CCO defaults to TEI of 1, and the remaining site TEIs uniformly allocated by CCO and is unique and non-duplicate to the present network. The broadcast period defaults to 2 routing periods and is modifiable. The hop count indicates the number of relay stations that need to pass from the CCO to the destination station, and the number of sub-stations indicates the number of sub-stations to which the station is connected.

The structure of the information of the station storage routing table is shown in fig. 4, and the structure of the station storage ordering table is shown in fig. 5, and the ordering table stores information which is screened from the routing table by the station and can be used as a new path:

the storage space occupied by each station in the station storage routing table information structure is 4+2 x N bytes, each entry stores one route, the number of route paths passing through the transit stations is 14 at most, wherein the first route is the main route, and the other routes are new routes collected.

After 2 routing periods are finished, the station sorts the routing table, and the sorting method is as shown in fig. 6, wherein M in the drawing is a fluctuation value, and is set to be 0.1, and the method can be configured:

ordering method for site selection path of FIG. 6

At most 5 stations can be carried as new agents, namely, at most 5 paths which are more than the current paths can be selected, the selected 5 paths are required to be in the same level, if the paths are not in the same level, less than 5 agents can be selected, and an agent change request message is constructed and sent.

The proxy change request message format is shown in table 1.

Table 1 proxy change request message format

The step S4 specifically comprises the following steps:

s43: updating the routing table information, constructing an agent change confirmation message, filling 1 (allowing change) in a result field, and jumping to S45;

s44: constructing a proxy change confirmation message and filling 0 (not allowing change) in a result field;

s45: and sending a proxy change confirmation message.

The proxy change acknowledge message format is shown in table 2.

Table 2 proxy change request acknowledgement message format

The step S5 is specifically as follows:

s52: analyzing and storing path information;

s53: and releasing the message.

Referring to fig. 7 to fig. 13, the technical scheme of the present invention is described by taking a broadband micro-power wireless intelligent meter reading network as an example, and the network topology of the broadband micro-power wireless intelligent meter reading network just completed is as shown in fig. 7, and the network topology is a tree topology, including a Central Coordinator (CCO), a proxy site (PCO) and a Site (STA). The network topology of the broadband micro-power wireless intelligent meter reading just networking in fig. 7 is only used to illustrate the method of proxy modification of the intelligent meter reading network of the present invention, and not to limit the application scenario of the present invention, and it should be obvious to those skilled in the art that the technical solution of the present invention is applied to the intelligent meter reading network of the power grid, regardless of the communication mode, the number of sites, the number of network layer levels, etc. of the intelligent meter reading network.

Example 1: the embodiment is a preferred implementation mode of the broadband micro-power wireless intelligent meter reading initial routing structure. Referring to fig. 8 and 9 (fig. 8 shows a CCO initial route configuration flowchart, fig. 9 shows an STA initial route configuration flowchart), the route configuration method of the present embodiment includes a CCO route configuration and an STA route configuration:

routing configuration of CCO:

1) After CCO is electrified, an MAC address is acquired, a white list is configured, a beacon frame and a network notification message are broadcast, and a receiving station is waited to request to access the network;

2) After receiving the request network access message, the CCO analyzes the MAC address and the routing relationship in the message and distributes the TEI;

1) The CCO judges whether networking is completed, if so, a network maintenance timer is started to carry out networking maintenance, and a network maintenance message sent by a website is received, and if not, the request of the website for network access is continuously received;

2) The CCO judges whether the network maintenance timer is overtime, if yes, the timer is closed, the state of the station is checked, and if no, the network maintenance message of the station is continuously received;

3) And clearing the information of the received network maintenance message, starting a timer, and re-receiving.

Routing configuration of STA:

1) The STA is powered on, acquires the MAC address and starts a monitoring timer;

2) The STA monitors the beacon frame and the network notification message, analyzes and stores the network information in the message, and prepares for the station to select a relay station to access the network;

3) The STA judges whether the monitoring timer overflows, if so, the stored information is screened to construct and send a request network entry message, if not, the jump is not completed 2, and the monitoring beacon frame and the network notification message are continued;

4) After sending the request network access message, the STA waits for receiving the request network access confirmation message;

5) The STA receives the request network access confirmation message, analyzes the routing relation between the TEI and the CCO in the message, and stores the routing relation in a routing table as an initial route;

6) The STA starts a network maintenance timer and sends a network maintenance message at regular time;

7) The STA receives the network maintenance message of surrounding sites, analyzes and stores the network maintenance message;

8) The STA judges whether the network maintenance timer overflows, if so, the timer is closed, a routing table is checked, if not, the STA jumps to the step 7) to continuously receive the network maintenance message of the site;

9) The STA judges whether to initiate the proxy change request message, if so, constructs and transmits the proxy change request message, if not, jumps to step 10);

10 The STA clears all other routing information except the initial route, starts the network maintenance timer, and re-receives.

Example 2: this embodiment is a preferred embodiment of the broadband micro-power wireless intelligent agent change request according to the present invention, and see fig. 10 to 13.

1) If so, selecting and storing the path to wait for sorting in a sorting table;

2) The stations are ordered and the set grade value which is increased from 1 is used as a new route, and if the number of the same grade value exceeds 5, 5 paths are randomly selected;

3) After the station selects a new route, constructing and initiating a proxy change request message, and waiting for receiving a proxy change request confirmation message;

4) After receiving the proxy change request message, the CCO analyzes the new proxy site and the old site carried in the message, judges whether to allow proxy change, if so, selects a new proxy site to construct a result field filling 1 in proxy change request confirmation and sends a proxy change confirmation message. If not, constructing a result field filling 0 in the proxy change request confirmation and sending a proxy change confirmation message;

5) The station receives the proxy change request message, analyzes the result field value in the message, if the result field value is not 0, analyzes the newly allocated proxy station in the message, modifies the path information, modifies the initial route in the routing table, and takes the new route as the new initial route;

6) And releasing the message.

Example 3: the present embodiment is a network topology after the broadband micro-power wireless intelligent meter reading site agent is changed, see fig. 12. The network topology is only used for illustrating the method of proxy modification of the intelligent meter reading network of the present invention, and is not limited to the application scenario of the present invention, and it should be obvious to those skilled in the art that the present invention is not limited to the method. Comparing the network topology after the network is formed at the beginning of fig. 7 with the network topology after the agent is changed in fig. 13, the compactness among stations is increased, the number of PCOs is greatly reduced, the hierarchy of the stations is reduced, and therefore the meter reading efficiency can be high and the congestion of message transmission in an air interface is reduced.

Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is intended to be covered by the claims of the present invention.

Claims

1. A method for forming a clustered network based on proxy modification, comprising: the method comprises the following steps:

s1: the CCO forms the entire network topology and establishes an initial route;

s2: the station establishes an initial route;

s3: the site actively initiates an agent change request message;

s5: the site receives the proxy change confirmation message and updates the route information;

the S1 specifically comprises the following steps:

s13: after a station is accessed to the network, CCO starts to perform network maintenance and sends a network maintenance message to surrounding stations;

the step S12 is specifically as follows:

s21: after the station is electrified, acquiring an MAC address, monitoring surrounding signals, analyzing and storing information after receiving a network notification message and a beacon frame, ending the monitoring time, constructing a network access request message, and waiting for receiving a network access success confirmation message;

s22: after receiving a successful network access confirmation message sent by the CCO, the station analyzes and stores the TEI number and initial routing information carried in the message, and sends a discovery beacon frame in a scheduled beacon time slot, otherwise, after receiving a failed network access confirmation message sent by the CCO, the station gives up the network and continues to monitor and search for a new network to attempt network access;

s23: after a station is accessed to the network, storing the routing information and the TEI number in a network maintenance message, and sending a discovery beacon frame and the network maintenance message to surrounding stations;

the step S3 is specifically as follows:

s34: the stored path information is ordered according to the route hop count, if the route hop count is the same, the stored path information is ordered according to the number of the sub-stations connected with the station, and if the number of the sub-stations connected with the station is the same, the stored path information is ordered according to the variance of the SNR;

after 2 routing cycles are completed, the station sorts the routing table.

2. A method of forming a clustered network based on proxy modification as claimed in claim 1, wherein: the step S4 specifically comprises the following steps:

s45: and sending a proxy change confirmation message.

3. A method of forming a clustered network based on proxy modification as claimed in claim 2, wherein: the step S5 specifically comprises the following steps:

s52: analyzing and storing path information;

s53: and releasing the message.