CN112867082B - Method, medium and system for acquiring secure multi-hop transmission path of wireless sensor network - Google Patents
Method, medium and system for acquiring secure multi-hop transmission path of wireless sensor network Download PDFInfo
- Publication number
- CN112867082B CN112867082B CN202011435087.7A CN202011435087A CN112867082B CN 112867082 B CN112867082 B CN 112867082B CN 202011435087 A CN202011435087 A CN 202011435087A CN 112867082 B CN112867082 B CN 112867082B
- Authority
- CN
- China
- Prior art keywords
- wireless node
- transmission path
- wireless
- node
- hop
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W40/00—Communication routing or communication path finding
- H04W40/02—Communication route or path selection, e.g. power-based or shortest path routing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/18—Self-organising networks, e.g. ad-hoc networks or sensor networks
Abstract
The invention discloses a method, a medium and a system for acquiring a secure multi-hop transmission path of a wireless sensor network. The acquisition method comprises the following steps: acquiring a transmission path set from a starting wireless node to a target wireless node through a transferred wireless node in a wireless sensor network, wherein the starting wireless node is a sensing node, the target wireless node is a gateway node, and the transferred wireless node is at least one-stage sink node; and determining an optimal transmission path from the transmission path set according to the uplink transmission bandwidth and the signal strength value of the initial wireless node. The embodiment of the invention can ensure the transmission safety and the information effectiveness, increase the reliability of the wireless network and ensure the safety of the multi-hop protocol under the condition of not increasing the power consumption of the sensing node.
Description
Technical Field
The invention relates to the technical field of wireless sensor networks, in particular to a method, a medium and a system for acquiring a secure multi-hop transmission path of a wireless sensor network.
Background
In the present stage, wireless sensor networks are rapidly developed, the number of mobile IoT terminals in china in 2015 is 7 hundred million, the number of mobile IoT terminals in 2018 is increased to 18 hundred million, the CAGR in 2015-2018 is about 37%, and the composite growth rate from 2019 to 2022 is expected to be 12.13%. Various concept projects such as the Internet of things industry, industry 4.0, smart city, car networking, VR/AR virtual reality, autopilot, 5G everything interconnection all need the sensor to support.
In conventional wireless sensor communication, a method for accessing a network is generally to distribute aggregation nodes to fixed stations in a certain geographic area. In the current wireless networking supporting multi-hop, a sink node needs to be configured locally in advance, and the path of each subsequent hop is determined and cannot be changed dynamically, so that a transmission path cannot be selected preferentially. If the sink node changes, the wireless link is broken. And the sensor wireless communication has a broadcast characteristic, is physically exposed, is generally deployed in an environment difficult to maintain and control, has higher requirements on node security, requires high network security, and is equipped with an effective network security mechanism.
Disclosure of Invention
The embodiment of the invention provides a method, a medium and a system for acquiring a secure multi-hop transmission path of a wireless sensor network, which aim to solve the problem that the transmission path in the prior art cannot be selected dynamically and preferentially.
In a first aspect, a method for acquiring a secure multi-hop transmission path of a wireless sensor network is provided, which includes: acquiring a transmission path set from a starting wireless node to a target wireless node through a transferred wireless node in a wireless sensor network, wherein the starting wireless node is a sensing node, the target wireless node is a gateway node, and the transferred wireless node is at least one-stage sink node; and determining an optimal transmission path from the transmission path set according to the uplink transmission bandwidth and the signal strength value of the initial wireless node.
In a second aspect, a computer-readable storage medium having computer program instructions stored thereon is provided; the computer program instructions, when executed by a processor, implement the method for acquiring a secure multi-hop transmission path of a wireless sensor network as described in the embodiment of the first aspect.
In a third aspect, a system for acquiring a secure multi-hop transmission path of a wireless sensor network is provided, including: a computer readable storage medium as described in the second aspect of the embodiments above.
Therefore, the embodiment of the invention can ensure the transmission safety and the information effectiveness, increase the reliability of the wireless network and ensure the safety of the multi-hop protocol under the condition of not increasing the power consumption of the sensing node.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a flowchart of a method for acquiring a secure multi-hop transmission path of a wireless sensor network according to an embodiment of the present invention;
FIG. 2 is a diagram illustrating transmission paths of wireless nodes of a wireless sensor network according to an embodiment of the present invention;
fig. 3 is a schematic diagram of an optimal transmission path of a wireless node of a wireless sensor network according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments of the present invention, belong to the protection scope of the present invention.
The embodiment of the invention discloses a method for acquiring a secure multi-hop transmission path of a wireless sensor network. As shown in fig. 1, the acquiring method includes the following steps:
step S1: and acquiring a transmission path set from the initial wireless node to the target wireless node through the transferred wireless node in the wireless sensor network.
The starting wireless node is a sensing node, the target wireless node is a gateway node, and the transit wireless node is at least one level of sink node. Specifically, the sensing node is a wireless sensor device. The sink node is a wireless node having at least one function of data collection, distribution, relay, etc., and may have at least one layer of sink node, and each layer may have at least one sink node. The gateway node directly has a network mode conversion function or has a network mode conversion function after being connected with related equipment, for example, the gateway node uploads data to the convergence server in a wired (RS 485/Ethernet) or wireless (GPRS/WIFI/3G/4G/5G) mode.
Specifically, the steps include the following processes:
1. for any two adjacent wireless nodes, acquiring a previous wireless node which can establish a single-hop transmission path with a next wireless node, and acquiring a previous optional wireless node set corresponding to the next wireless node.
Specifically, the upper-level wireless node that can establish the single-hop transmission path is determined by the following process:
(1) And acquiring the screening parameters between the next-level wireless node and the previous-level wireless node.
Wherein, the screening parameters include: directivity of antenna pair, transmission bandwidth/frequency point available for traffic channel, transmission bandwidth/frequency point available for control channel and link communication quality. The Directivity of the antenna pair is specifically a Directivity coefficient (Directivity) of the antenna pair, and the link communication quality includes: received signal strength (dB), connectivity (on/off), end-to-end delay (ms), bit error rate (10-N), and packet loss rate (%).
(2) And determining the upper-level wireless node of which the screening parameter meets the preset standard as the upper-level wireless node capable of establishing a single-hop transmission path with the lower-level wireless node.
The preset standard can be determined according to actual requirements, that is, the directivity of the antenna pair, the available transmission bandwidth/frequency point of the service channel, the available transmission bandwidth/frequency point of the control channel, and the index and the numerical value specifically satisfied by the link communication quality are determined according to the actual requirements.
Specifically, the selectable set of wireless nodes further includes: the method comprises the following steps of selecting wireless node type information, selecting wireless node logical address information, selecting wireless node time synchronization information, supported single-hop radio frequency transmission power information, available single-hop transmission bandwidth information or frequency point information, available single-hop radio frequency transmission power information, supported single-hop wireless port number information, and supported single-hop transmission bandwidth information or frequency point information.
2. And according to the sequence from bottom to top, acquiring the wireless nodes communicated between two adjacent stages from the selectable wireless node set, and establishing a transmission path set from the initial wireless node to the target wireless node through the wireless nodes communicated step by step.
The wireless node communicated between two adjacent stages means that the wireless node is the end point of the single-hop transmission path of the next-stage wireless node and is also the starting point of the single-hop transmission path of the wireless node and the previous-stage wireless node.
It should be understood that the adjacent two levels of wireless nodes on the transmission paths in the transmission path set pass the security authentication. The security authentication can adopt a secret SM7 low-power consumption encryption mode. The security authentication principle of the SM7 secret key comprises the following steps: and the unique ID of the SM7 chip is encrypted and bound with the ID of the sensor, so that the sensor is prevented from being falsely used. The identity authentication and data encryption protocol of the SM7 cryptographic algorithm refers to international standards, and is optimized properly according to the special architecture of the power sensing network, so that the protocol complexity and the overhead in the network access initialization and operation process are reduced as much as possible on the premise of not reducing the safety. Based on this, the security authentication method of the embodiment of the present invention is as follows:
(1) The next-level wireless node sends a security identity authentication request to the previous-level wireless node.
Wherein the security identity authentication request comprises a node random number.
(2) After the previous-stage wireless node receives the node random number, the node random number is encrypted through the local secret key to obtain a first encryption numerical value, and the next-stage wireless node returns the self security chip version, the chip serial number and the first encryption numerical value.
(3) And the next-stage wireless node encrypts the node random number through the local symmetric key to obtain a second encrypted value, and compares the second encrypted value with the received first encrypted value.
(4) And if the second encryption numerical value is the same as the first encryption numerical value, the fact that the upper-level wireless node and the lower-level wireless node pass the security authentication is determined.
The wireless nodes carry out dynamic identity verification, programmable source point data encryption and inter-node encryption functions are achieved, and transmission safety is improved by eliminating the wireless nodes which do not meet safety certification.
In addition, the signal transmission quality authentication is performed between the adjacent two levels of wireless nodes on the transmission paths in the transmission path set. Specifically, the method for authenticating the signal transmission quality comprises the following steps: after a wireless node at any one level of two adjacent levels sends a single-hop path detection signal to a wireless node at the other level, if the single-hop path detection signal received by the wireless node at the other level meets the transmission quality requirement, the wireless node at the two adjacent levels is determined to pass signal transmission quality authentication. Wherein the transmission quality requirements include: the signal strength of the single-hop path detection signal is greater than a set threshold.
Step S2: and determining an optimal transmission path from the transmission path set according to the uplink transmission bandwidth and the signal strength value of the initial wireless node.
Specifically, the uplink transmission bandwidth is selected from the transmission path set to be not less than the uplink transmission bandwidth of the initial wireless node, and the transmission path with the minimum signal strength value is the optimal transmission path.
Preferably, after the optimal transmission path is determined, the transmission is performed through the optimal transmission path. And the data can be transmitted in a data encryption mode in the transmission process, so that the transmission safety is improved. Specifically, in the transmission process, the next-level wireless node in the two adjacent levels encrypts a signal sent by the next-level wireless node by using the chip serial number of the previous-level wireless node and sends the encrypted signal to the previous-level wireless node, and the previous-level wireless node decrypts the signal by using the chip serial number of the previous-level wireless node after receiving the signal. And the like, and the transmission is carried out step by step.
The embodiment of the invention also discloses a computer readable storage medium, wherein the computer readable storage medium is stored with computer program instructions; the computer program instructions, when executed by a processor, implement the method for acquiring the secure multi-hop transmission path of the wireless sensor network according to the embodiment.
The embodiment of the invention also discloses a system for acquiring the safe multi-hop transmission path of the wireless sensor network, which comprises the following steps: a computer readable storage medium as in the above embodiments.
The technical solution of the present invention is further described below with a specific embodiment. As shown in fig. 2, the originating wireless node is S1 and the target gateway node is GW1. A set of transmission paths between S1 and GW1 is obtained. Specifically, the upper-level wireless node that can establish a single-hop transmission path with S1 includes (A1, A2, A3, A4), that is, S1 can respectively establish four single-hop transmission paths with A1, A2, A3, A4. Similarly, from bottom to top, the previous-stage wireless node that can establish a single-hop transmission path with A1 includes (B2, B3), the previous-stage wireless node that can establish a single-hop transmission path with A2 includes (B1, B2), the previous-stage wireless node that can establish a single-hop transmission path with A3 includes (B2, B3), and the previous-stage wireless node that can establish a single-hop transmission path with A4 includes (B1); the upper-stage wireless node which can establish a single-hop transmission path with B1 includes (GW 1), the upper-stage wireless node which can establish a single-hop transmission path with B2 includes (GW 1, GW 2), and the upper-stage wireless node which can establish a single-hop transmission path with B3 includes (GW 1).
According to the sequence from bottom to top, the set of transmission paths from S1 to GW1 that is established includes:
S1-A1-B2-GW1, uplink bandwidth of 200MHz and comprehensive signal intensity of-71 dB
S1-A1-B3-GW1, uplink bandwidth of 400MHz and comprehensive signal intensity of-74 dB
S1-A2-B1-GW1, uplink bandwidth of 200MHz and comprehensive signal intensity of-78 dB
S1-A2-B2-GW1, uplink bandwidth of 300MHz and comprehensive signal intensity of-63 dB
e.S1-A3-B3-GW1, uplink bandwidth of 500MHz, and integrated signal intensity of-77 dB
S1-A4-B1-GW1, uplink bandwidth of 300MHz and comprehensive signal intensity of-65 dB
The uplink transmission bandwidth required by S1 is 300MHz. The transmission paths not less than the uplink transmission bandwidth of the starting wireless node are b, d, e, and f, and the optimal transmission path is selected as d in combination with the criterion of minimum signal strength value, as shown in fig. 3.
In summary, the embodiment of the invention can ensure transmission security and information validity, increase wireless network reliability and ensure multi-hop protocol security without increasing power consumption of the sensing node.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (9)
1. A method for acquiring a secure multi-hop transmission path of a wireless sensor network is characterized by comprising the following steps:
acquiring a transmission path set from an initial wireless node to a target wireless node through a transferred wireless node in a wireless sensor network, wherein the initial wireless node is a sensing node, the target wireless node is a gateway node, and the transferred wireless node is at least one-stage sink node;
determining an optimal transmission path from the transmission path set according to the uplink transmission bandwidth and the signal strength value of the initial wireless node;
the adjacent two-stage wireless nodes on the transmission paths in the transmission path set pass safety authentication;
the method for the security authentication comprises the following steps:
a next-level wireless node sends a security identity authentication request to an upper-level wireless node, wherein the security identity authentication request comprises a node random number;
after receiving the node random number, the previous wireless node encrypts the node random number through a local key to obtain a first encryption numerical value, and returns the self security chip version, the chip serial number and the first encryption numerical value to the next wireless node;
the next-stage wireless node encrypts the node random number through a local symmetric key to obtain a second encrypted value, and compares the second encrypted value with the received first encrypted value;
and if the second encryption numerical value is the same as the first encryption numerical value, determining that the upper-level wireless node and the lower-level wireless node pass the security authentication.
2. The method for acquiring the secure multi-hop transmission path of the wireless sensor network according to claim 1, wherein the step of acquiring the transmission path set from the initial wireless node to the target wireless node via the intermediate wireless node in the wireless sensor network comprises:
for any two adjacent wireless nodes, acquiring a previous wireless node which can establish a single-hop transmission path with a next wireless node, and acquiring a previous optional wireless node set corresponding to the next wireless node;
and sequentially acquiring the wireless nodes communicated between two adjacent stages from the selectable wireless node set according to the sequence from bottom to top, and establishing a transmission path set from the initial wireless node to the target wireless node through the gradually communicated transit wireless nodes.
3. The method for acquiring the secure multi-hop transmission path of the wireless sensor network according to claim 2, wherein the selectable set of wireless nodes further comprises: the method comprises the following steps of selecting wireless node type information, selecting wireless node logical address information, selecting wireless node time synchronization information, supported single-hop radio frequency transmission power information, available single-hop transmission bandwidth information or frequency point information, available single-hop radio frequency transmission power information, supported single-hop wireless port number information, and supported single-hop transmission bandwidth information or frequency point information.
4. The method for acquiring a secure multi-hop transmission path of a wireless sensor network according to claim 3, wherein before the step of acquiring the previous-stage wireless node that can establish a single-hop transmission path with the next-stage wireless node, the method further comprises:
obtaining screening parameters between a next-level wireless node and a previous-level wireless node, wherein the screening parameters comprise: the directivity of the antenna pair, the available transmission bandwidth/frequency point of the service channel, the available transmission bandwidth/frequency point of the control channel and the link communication quality;
and determining the upper-level wireless node of which the screening parameter meets the preset standard as the upper-level wireless node capable of establishing a single-hop transmission path with the lower-level wireless node.
5. The method for acquiring the secure multi-hop transmission path of the wireless sensor network according to claim 1, wherein: the adjacent two stages of wireless nodes on the transmission paths in the transmission path set pass signal transmission quality authentication;
the method for authenticating the signal transmission quality comprises the following steps:
after a wireless node at any one of two adjacent stages sends a single-hop path detection signal to a wireless node at the other stage, if the single-hop path detection signal received by the wireless node at the other stage meets the transmission quality requirement, the wireless nodes at the two adjacent stages are determined to pass signal transmission quality authentication;
wherein the transmission quality requirements include: the signal intensity of the single-hop path detection signal is greater than a set threshold.
6. The method for acquiring a secure multi-hop transmission path of a wireless sensor network according to claim 1, wherein the step of determining an optimal transmission path from the transmission path set according to the uplink transmission bandwidth and the signal strength value of the starting wireless node comprises:
and selecting the uplink transmission bandwidth not less than the uplink transmission bandwidth of the initial wireless node from the transmission path set, wherein the transmission path with the minimum signal strength value is an optimal transmission path.
7. The method for acquiring a secure multi-hop transmission path of a wireless sensor network according to claim 1, wherein after the step of determining an optimal transmission path from the transmission path set according to the uplink transmission bandwidth and the signal strength value of the starting wireless node, the method further comprises:
carrying out signal transmission through the optimal transmission path;
in the transmission process, the next-level wireless node in the two adjacent levels encrypts a signal sent by the next-level wireless node by using the chip serial number of the previous-level wireless node and sends the encrypted signal to the previous-level wireless node, and the previous-level wireless node decrypts the signal by using the chip serial number of the previous-level wireless node after receiving the signal.
8. A computer-readable storage medium characterized by: the computer readable storage medium having stored thereon computer program instructions; the computer program instructions, when executed by a processor, implement the method for acquiring the secure multi-hop transmission path of the wireless sensor network according to any one of claims 1 to 7.
9. A system for acquiring a secure multi-hop transmission path of a wireless sensor network is characterized by comprising: the computer-readable storage medium of claim 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011435087.7A CN112867082B (en) | 2020-12-09 | 2020-12-09 | Method, medium and system for acquiring secure multi-hop transmission path of wireless sensor network |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011435087.7A CN112867082B (en) | 2020-12-09 | 2020-12-09 | Method, medium and system for acquiring secure multi-hop transmission path of wireless sensor network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112867082A CN112867082A (en) | 2021-05-28 |
| CN112867082B true CN112867082B (en) | 2022-12-23 |
Family
ID=75997130
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011435087.7A Active CN112867082B (en) | 2020-12-09 | 2020-12-09 | Method, medium and system for acquiring secure multi-hop transmission path of wireless sensor network |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112867082B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1668005A (en) * | 2005-02-21 | 2005-09-14 | 西安西电捷通无线网络通信有限公司 | An access authentication method suitable for wired and wireless network |
| CN107135507A (en) * | 2016-02-26 | 2017-09-05 | 中兴通讯股份有限公司 | A kind of return radio path information acquisition method and device |
| CN108064064A (en) * | 2017-12-20 | 2018-05-22 | 浙江省公众信息产业有限公司 | Wireless sensor network Ad Hoc is by method and apparatus |
| CN110406498A (en) * | 2019-07-12 | 2019-11-05 | 深圳市元征科技股份有限公司 | A kind of control method for vehicle and device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8849926B2 (en) * | 2010-08-06 | 2014-09-30 | Simon Fraser University | System and method for self-calibrating, self-organizing and localizing sensors in wireless sensor networks |
| US9942944B2 (en) * | 2014-12-29 | 2018-04-10 | Intel IP Corporation | Network-initiated discovery and path selection procedures for multi-hop underlay networks |
-
2020
- 2020-12-09 CN CN202011435087.7A patent/CN112867082B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1668005A (en) * | 2005-02-21 | 2005-09-14 | 西安西电捷通无线网络通信有限公司 | An access authentication method suitable for wired and wireless network |
| CN107135507A (en) * | 2016-02-26 | 2017-09-05 | 中兴通讯股份有限公司 | A kind of return radio path information acquisition method and device |
| CN108064064A (en) * | 2017-12-20 | 2018-05-22 | 浙江省公众信息产业有限公司 | Wireless sensor network Ad Hoc is by method and apparatus |
| CN110406498A (en) * | 2019-07-12 | 2019-11-05 | 深圳市元征科技股份有限公司 | A kind of control method for vehicle and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112867082A (en) | 2021-05-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7907936B2 (en) | Communication system, wireless-communication device, and control method therefor | |
| US20160150459A1 (en) | Techniques to support heterogeneous network data path discovery | |
| JP6240273B2 (en) | Authentication using DHCP service in mesh networks | |
| KR101033345B1 (en) | Transporting management traffic through a multi-hop mesh network | |
| US8615603B2 (en) | Wireless LAN system, wireless LAN device, and storage medium having stored therein wireless LAN program | |
| CN110365470B (en) | Key generation method and related device | |
| US20150264627A1 (en) | System and method for digital communication between computing devices | |
| US7697516B2 (en) | Method and apparatus for pre-admitting a node to a mesh network | |
| CN106878165B (en) | Data transmission method and device | |
| US20090059934A1 (en) | Method and device for providing a bridge in a network | |
| CN107846270B (en) | Transmission strategy configuration method and device, and information transmission method and device | |
| CN110351747B (en) | Method and apparatus for configuring relay node | |
| US20110208968A1 (en) | Wireless lan device, wireless lan system, and communication method for relaying packet | |
| CN105981470A (en) | Methods and apparatuses for handling communication in a communication system comprising an access point and a wire line network node connected via wire line to the access point | |
| US11523277B2 (en) | Method of dynamically provisioning a key for authentication in relay device | |
| CN113923799A (en) | Wireless backhaul communication processing method and related device | |
| Sadakale et al. | TAD-HOC routing protocol for efficient VANET and infrastructure-oriented communication network | |
| KR20150135399A (en) | Mechanism to limit signaling storms over a network | |
| WO2018137209A1 (en) | Service data transmission method, first communication node and base station | |
| CN110662297B (en) | Signaling processing method, node and device | |
| CN110636636A (en) | Signaling transmission method and device and network equipment | |
| CN113518475B (en) | Communication method, device and system | |
| CN112867082B (en) | Method, medium and system for acquiring secure multi-hop transmission path of wireless sensor network | |
| US20130191635A1 (en) | Wireless authentication terminal | |
| DK3262864T3 (en) | Establishing an X2 connection using virtual terminals |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |