CN114759953B

CN114759953B - Logic phase selection method applied to HPLC

Info

Publication number: CN114759953B
Application number: CN202210661368.7A
Authority: CN
Inventors: 张校臣; 顾雄飞; 封其源; 魏建刚; 赵国龙
Original assignee: Jiayuan Technology Co Ltd
Current assignee: Jiayuan Technology Co Ltd
Priority date: 2022-06-13
Filing date: 2022-06-13
Publication date: 2022-09-02
Anticipated expiration: 2042-06-13
Also published as: CN114759953A

Abstract

The invention discloses a logic phase selection method applied to HPLC, which comprises the following steps that according to the characteristics of the HPLC technology, two factors, namely the number of beacons and the signal-to-noise ratio (SNR), are comprehensively received by a node before network access to select a logic phase; updating the logic phase of the network in real time according to the number of received beacons and the signal-to-noise ratio (SNR) after the network is accessed; the logic phase of the slave node is determined according to the communication rate on three phases during agent change and other phases, and the slave node performs message interaction according to the logic phase information at different phases, so that the sending success rate of the message is improved, the communication performance is enhanced, the change of a network is reduced, and the stability of the system is improved.

Description

Logic phase selection method applied to HPLC

Technical Field

The invention relates to the technical field of power line high-speed carrier communication, in particular to a logic phase selection method applied to HPLC.

Background

The High Power Line Communication (HPLC) technology is a High-speed Power line communication technology, and refers to a technology for performing data communication using a Power line as a transmission medium. The power line communication can be divided into narrow-band low-speed power line communication, narrow-band high-speed power line communication and broadband high-speed power line communication according to working frequency bands, the usable frequency range of the narrow-band power line communication is 3kHz to 500kHz, the bandwidth is relatively narrow, communication service with low transmission rate can be provided, the anti-interference capability is weak, and the success rate of one-time meter reading is difficult to break through more than 90%. The broadband high-speed power line communication working frequency range facing the power meter reading is 2 MHz-12 MHz, has relatively wide bandwidth, can provide data transmission rate of hundreds of kbps to several Mbps, and the noise of the power line in a high frequency band is relatively weak, and compared with narrow-band power line communication, the communication reliability and stability are obviously improved.

Currently, before establishing a communication link by HPLC, ad hoc network is first performed, so that a master node and a plurality of slave nodes establish a topology of a tree network, as shown in fig. 1. In the network maintenance process, the nodes periodically send messages such as heartbeat detection, discovery lists, communication success rate report and the like for evaluating network routes to form more comprehensive network topology information. In the communication process between the slave node and the father node, if the communication link is interfered to cause the reduction of the communication rate, the slave node can evaluate a new proxy father node and carry out proxy change of the father node so as to obtain a routing table item with a better communication link.

The HPLC technology supports the channel access mechanism of TDMA and CSMA/CA, and in the CSMA time slot, the nodes can occupy the channel for message transmission only after avoiding channel competition collision. The whole CSMA time slot needs to be divided in a balanced way according to the number of phase lines, and when nodes communicate with each other, message interaction needs to be carried out in the corresponding phase line time slot. The master node is essentially three phase powered and therefore can communicate data at any of the phases A, B, C. The slave nodes are mostly single-phase power supplies, and data communication is only carried out on the affiliated physical phase. However, the slave node sends the message in the affiliated physical phase, and actually, it cannot be guaranteed that the communication performance is not good in other phases, and on the contrary, the communication rate may be better in other non-affiliated physical phases. In this case, if data interaction is always performed on the phase, the communication performance is reduced, and the system stability is insufficient.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a logical phase selection method applied to HPLC. In the method, a concept of "logical phase" is proposed, which indicates a phase with the best communication performance among three phases. According to the characteristics of the HPLC technology, the nodes determine the logic phase of the nodes before network access, after network access, during proxy change and other stages, and send the messages on the CSMA time slot corresponding to the phase line time slice according to the logic phase instead of the physical phase, so that the success rate of sending the messages is improved, the communication performance is enhanced, the change of the network is reduced, and the stability of the system is improved.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a logic phase selection method applied to HPLC is applied to a logic phase selection stage of a slave node before network access, and comprises the following steps:

step 101, the slave node monitors a beacon frame to acquire network information;

102, selecting a candidate father node from the slave nodes and judging whether the candidate father node is a master node or not, if so, entering a step 103; if not, acquiring the logic phase of the candidate father node, enabling the logic phase of the candidate father node to be the same as the logic phase of the candidate father node, and ending the process;

103, acquiring signal-to-noise ratios (SNR) of the slave node on three phases, judging whether the SNR of one phase in the three phases of the slave node is greater than that of the other two phases by a threshold value M, if so, selecting the phase with the greater SNR as a logic phase of the slave node, and ending the process; if not, go to step 104;

step 104, judging whether the beacon receiving quantity of one phase in the three phases of the slave node is more than that of the other two phases, if so, selecting the phase with the more beacon receiving quantity as the logic phase of the slave node, and ending the process; if not, go to step 105;

step 105, judging whether the SNR of one phase in the three phases of the slave node is larger than that of the other two phases, if so, selecting the phase with the larger SNR as the logic phase of the slave node, and ending the process; if not, then the process goes to step 103,

the method is applied to a logic phase selection stage after the slave node accesses the network, and comprises the following steps:

step 201, the slave node judges whether the father node is the master node, if yes, step 202 is entered; if not, the logic phase of the slave node is unchanged, and the process is ended;

step 202, judging whether the number of beacons received from the new phase in the node is more than the original phase by a percentage a, if so, entering step 203; if not, go to step 204;

step 203, judging whether the signal-to-noise ratio SNR of the slave node on the new phase is greater than or equal to the signal-to-noise ratio SNR of the original phase, if so, entering step 206; if not, go to step 204;

step 204, continuously monitoring T beacon periods, judging whether the SNR of one phase in the three phases of the slave node is larger than the SNR of the other two phases, and if so, entering step 205; if not, the process is ended;

step 205, determine whether the phase is the original logical phase, if yes, the process is ended; if not, go to step 206;

step 206, selecting the new phase as its own logic phase,

the method is applied to a logic phase selection phase when the slave node agent changes, and comprises the following steps:

step 301, selecting candidate parent nodes from nodes;

step 302, judging whether the candidate father node is a main node, if so, entering step 303; if not, acquiring the logic phase of the candidate father node, enabling the logic phase of the candidate father node to be the same as the logic phase of the candidate father node, and ending the process;

step 303, calculating the communication rate on the three phases;

in step 304, the phase with the largest communication rate is selected as the logic phase of the phase.

Preferably, the method further comprises the following steps:

step 401, the slave node sends a message through the logic phase.

Preferably, the threshold value M is set to 6dB to 8 dB.

Preferably, the percentage a is between 65% and 75%.

Preferably, the number T of the beacon periods is 3-8.

Preferably, the threshold value N is set to 9dB to 11 dB.

Preferably, the communication rate is obtained by comprehensive calculation according to the number of beacons received on three phases and the message in network maintenance.

Based on the technical scheme, the invention has the beneficial effects that:

1) according to the invention, the logic phase is selected by comprehensively receiving two factors of the number of beacons and the signal-to-noise ratio (SNR) before network access, so that the optimal communication phase can be accurately selected, the success rate of network access message transmission is improved, and the network access speed is increased;

2) the invention updates the logic phase in real time according to the number of received beacons and the signal-to-noise ratio (SNR) after the network is accessed, so that the transceiving performance of the message can be maintained to the maximum, the change of the network is reduced, and the stability of the system is improved;

3) the invention can switch the logic phase to the best phase in time when the route changes by selecting the logic phase when the agent changes, thereby avoiding the reduction of the communication performance and ensuring the success rate of message receiving and sending.

Drawings

FIG. 1 is a schematic diagram of the basic network topology of HPLC in one embodiment;

FIG. 2 is a flow diagram of a method for selecting logical phases from nodes before network entry in one embodiment;

FIG. 3 is a flow diagram of a method for selecting logical phases after network entry from a node in one embodiment;

figure 4 is a flow diagram of a method for selecting logical phases upon change from a node agent in one embodiment.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Referring to fig. 1 and 2, the present embodiment provides a logic phase selection method applied to HPLC, applied to a logic phase selection stage before network entry of a slave node, and the method includes the following steps:

step 101, a slave node monitors a beacon frame, acquires network information, and selects a candidate father node through comprehensive judgment;

the slave node listens for a beacon frame, and the beacon of the master node that is listened to is A, B, C three-phase beacon information. The beacon frame is a management message which is sent by the master node and the slave node and carries network management and maintenance information and is used for a specific purpose. The master node will periodically transmit beacon frames on A, B, C three phases respectively, and the slave nodes will typically transmit beacon frames only on their own phases.

And 102, judging whether the father node is a main node or not, if the father node is not the main node, acquiring the logic phase of the father node, wherein the logic phase of the father node is the same as the logic phase of the father node, and ending the process. Otherwise, entering step 3;

and 103, judging whether the SNR of the phase 1 is 6dB greater than the SNR of the other two phases, if so, selecting the logic phase 1 as the logic phase of the logic phase, and ending the process. Otherwise, go to step 104;

step 104, determining whether the number of beacons received in phase 2 is greater than that of the other two phases, if so, selecting the logical phase 2 as its own logical phase, and ending the process. Otherwise, entering step 105;

and 105, judging whether the signal-to-noise ratio SNR of the phase 3 is larger than the signal-to-noise ratios SNR of the other two phases, if so, selecting the logic phase 3 as the logic phase of the logic phase, and ending the process. Otherwise, step 103 is entered.

In this embodiment, the selection of the logic phase before network access is mainly determined by integrating two factors, i.e., the SNR of the signal to noise ratio and the number of received beacons, of the three phases. And preferably selecting the phase with the SNR larger than other phases with the SNR larger than 6dB, if the SNR difference is not large, selecting the phase with the larger number of the received beacons, and if the number of the received beacons is the same, selecting the phase with the larger SNR. Through steps 102 to 105, the optimal communication phase, that is, the logic phase, can be accurately selected, the success rate of sending the network access message is improved, and the network access speed is increased.

Referring to fig. 3, the present embodiment provides a logic phase selection method applied to HPLC, applied to a logic phase update stage after network access from a node, where the method includes the following steps:

step 201, judging whether the father node is the main node, if not, the logic phase is unchanged or the same as the logic phase of the father node, and ending the process. Otherwise, go to step 202;

step 202, judging whether the number of beacons received on the new phase is 70% more than that of the original phase, if so, entering step 203, otherwise, entering step 204;

step 203, judging whether the SNR on the new phase is larger than or equal to the SNR of the original phase, if so, entering step 206, otherwise, entering step 204;

the steps 202 and 203 are the first conditions of logic phase update after network entry, that is, the number of beacons received at the new phase is 70% higher than the original phase, and the SNR is also the best.

Step 204, continuously monitoring 5 beacon periods, and determining whether the SNR at a certain phase is 10dB greater than the SNR at the other two phases, and if so, entering step 205. Otherwise, the flow ends.

In step 204, the second condition of the logic phase update after network entry is that, in 5 consecutive beacon periods, the SNR of the new phase is 10dB greater than the SNRs of the other two phases, and the number of received beacons is greater than 0.

Step 205, determine whether the phase is the original logical phase, if so, the process ends. Otherwise, go to step 206;

this new phase is selected as its own logical phase, step 206.

In the embodiment, the logic phase of the user is updated in real time according to the number of received beacons and the signal-to-noise ratio (SNR) after the user accesses the network, so that the receiving and sending performance of the message can be maintained to the maximum, the change of the network is reduced, and the stability of the system is improved.

Referring to fig. 4, the present embodiment provides a logic phase selection method applied to HPLC, applied to a logic phase selection phase when a node agent changes, and the method includes the following steps:

step 301, selecting a candidate parent node;

step 302, judging whether the father node is a main node or not, if not, acquiring the phase of the father node, wherein the logic phase is the same as the phase of the father node, the process is ended, otherwise, entering step 203;

step 303, respectively calculating the communication rates on the A, B, C three phases;

the communication rate in the three phases is a communication rate calculated comprehensively according to the number of beacons received in the three phases and other messages in network maintenance. The communication rate is a quantitative criterion that can reflect the quality of communication with other nodes or phases.

Step 304, selecting the phase with the maximum communication rate as the logic phase of the phase.

In the embodiment, through the selection of the logic phase when the agent changes, the logic phase can be switched to the optimal phase in time when the route changes, thereby avoiding the reduction of the communication performance and ensuring the success rate of message receiving and sending.

Experimental conditions

In the experiment, 1 master node and 500 slave nodes are adopted to perform ad hoc network test. Under the condition that the experimental environment and the number of the slave nodes are the same, meter reading conditions after networking are respectively tested under two different scenes of using a physical phase and a logic phase. In the experiment, 500 slave nodes are respectively subjected to meter reading test, each slave node reads 5000 times, and the successful meter reading number and the average meter reading use time are respectively calculated, which are specifically shown in the following table

	Number of slave nodes	Total number of times of reading	Number of successful meter readings	Success rate of meter reading	Meter reading average time (unit ms)	Total number of agent changes
							Physical phase scene	500	1500000	1449750	96.65%	1087	168
Logical phase scenarios	500	1500000	1497300	99.82%	893	125

From experimental results, the logical phase scene provided by the invention improves the meter reading success rate and the meter reading efficiency. The successful meter reading power can be improved by 3.28%, the total meter reading efficiency is improved by a large amount, the meter reading efficiency is improved by about 17.84%, and the agent change is reduced by 25.6%.

From experimental data, the scheme of the logic phase improves the communication quality, reduces the change of a network and improves the stability of a system.

The above description is only a preferred embodiment of the disclosed logical phase selection method applied to HPLC, and is not intended to limit the scope of the embodiments of the present disclosure. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the embodiments of the present disclosure should be included in the protection scope of the embodiments of the present disclosure.

Claims

1. A logic phase selection method applied to HPLC, which is applied to a logic phase selection stage of a slave node before network access, and comprises the following steps:

step 101, a slave node monitors a beacon frame to acquire network information;

step 102, selecting a candidate father node from the slave nodes and judging whether the candidate father node is a master node or not, if so, entering step 103; if not, acquiring the logic phase of the candidate father node, enabling the logic phase of the candidate father node to be the same as the logic phase of the candidate father node, and ending the process;

103, acquiring signal-to-noise ratios (SNRs) of the slave nodes on three phases, judging whether the SNRs of one phase in the three phases of the slave nodes are larger than a threshold value M than those of the other two phases, if so, selecting the phase with the larger SNR as a logic phase of the slave node, and ending the process; if not, go to step 104;

step 206, selecting the new phase as its own logic phase,

the method is applied to a logic phase selection phase when a slave node agent changes, and comprises the following steps:

step 301, selecting candidate parent nodes from nodes;

step 303, calculating the communication rate on the three phases, wherein the communication rate is obtained by comprehensively calculating the number of beacons received on the three phases and the messages in network maintenance, and the communication rate is a quantization standard which can reflect the communication quality with other nodes or phases;

2. The method of claim 1, further comprising the steps of:

step 401, the slave node sends a message through the logic phase.

3. A logical phase selection method for HPLC according to claim 1, wherein said threshold M is set at a value between 6dB and 8 dB.

4. A method of logical phase selection for HPLC according to claim 1, wherein said percentage a is a value between 65% and 75%.

5. The method of claim 1, wherein the number T of beacon periods is a number between 3 and 8.

6. The method of claim 1, wherein the threshold N is set to a value between 9dB and 11 dB.