CN111491303B

CN111491303B - LoRa-Mesh-based building communication system and building communication ad hoc network method

Info

Publication number: CN111491303B
Application number: CN202010281197.6A
Authority: CN
Inventors: 许瑜超; 叶翔
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2022-06-24
Anticipated expiration: 2040-04-10
Also published as: CN111491303A

Abstract

The invention belongs to the technical field of communication of the Internet of things, and particularly relates to a building communication system based on LoRa-Mesh and a building communication ad hoc network method, wherein a sensor in the system is used for sending data collected from third-party equipment in a building to a node; the node is used for transmitting data to the gateway; the gateway is arranged at a certain position according to the height of the building and used for transmitting data to the cloud end; the cloud end is intensively deployed on a public cloud and used for distributing data to corresponding third-party application servers outside the building according to the characteristics of the data message; the nodes and the gateways are continuously powered by a power supply, the communication protocol of the nodes and the gateways is LoRa, the routing protocol is RPL, and Mesh networks are automatically formed among different nodes and among the nodes and the gateways through the RPL. The invention enables the protocol of the sensor to be converted from LoRa to Bluetooth, so that the Bluetooth sensor has lower cost and longer service life; and the RPL protocol is adopted, so that the gateways can communicate with each other, the networking is automatic, and the construction and maintenance cost is reduced.

Description

LoRa-Mesh-based building communication system and building communication ad hoc network method

Technical Field

The invention belongs to the technical field of communication of the Internet of things, and particularly relates to a building communication system based on LoRa-Mesh and a building communication ad hoc network method.

Background

The technology of the internet of things is a technological breakthrough in an epoch-making process after the technology of the internet. The development of internet and cloud computing technology fully realizes the link between people, and software serves to greatly change our lives. With the rise of the internet of things and edge computing, the object-to-object linkage can be realized in the future, and the induction service can permeate into every corner of our life. With the development of intelligent broadcasting and television, broadcasting and television networks in various regions begin to build and explore the Internet of things and search for a new business mode. Particularly, in the application of the narrowband internet of things, the LoRa technology is common in networking, and a case with a lot of achievements is generated.

As is well known, the basis of the narrow-band internet of things is LPWAN (Low-Power Wide-Area Network), which has characteristics of small data volume, long-distance transmission and Power saving, so that the technology is very colorful in the application field of the internet of things. NBIoT, LoRa, Sigfox all use large outdoor base stations as cores to send and receive signals to and from various corners of cities and buildings, thereby realizing wireless communication. In practical application, because some buildings have complex structures, the traditional LoRa networking mode uses a star topology, and has many defects, such as that the real universal connection cannot be provided for the whole building, especially for special areas such as basements, and due to the poor duty ratio limitation and link quality, data loss is often caused, and the network use is difficult.

Disclosure of Invention

In order to solve the technical problem, the invention provides a building communication system based on LoRa-Mesh and a building communication ad hoc network method, which adopt the networking technology of the LoRa-Mesh and simultaneously superpose Bluetooth communication to form a narrow-band Internet of things, form a LoRa-Mesh network in a building by indoor LoRa nodes and gateways, take the gateways as a core, expand the network coverage from the inside of the building to the outside of the building, achieve the interconnection of each building through cloud service, and effectively solve the coverage of signals in the building and the access of a large number of nodes. Through combining together with bluetooth, realize the nimble access of loRa node and third party's equipment, realize intelligent building's narrowband thing networking construction.

The invention is realized in such a way, and provides a building communication system based on LoRa-Mesh, which comprises a sensor, a node, a gateway, a cloud end and a third-party application server end, wherein:

the sensor is used for sending data collected from third-party equipment in the building to the node;

the nodes are distributed in each floor of the building and used for transmitting data to the gateway;

the gateway is arranged at a certain position according to the height of the building and used for transmitting data to the cloud end;

the cloud end is intensively deployed on the common cloud and used for distributing the data to the corresponding third-party application server side outside the building according to the characteristics of the data message;

the nodes and the gateways are continuously powered by a power supply, the communication protocol of the nodes and the gateways is LoRa, the routing protocol of the nodes and the gateways is RPL, and Mesh networks are automatically formed among different nodes and among the nodes and the gateways through the RPL.

Further, the sensor includes LoRa sensor and bluetooth sensor.

Furthermore, at least one node is deployed in each floor, and the access mode of the sensor and the node is LoRa or Bluetooth.

Further, when the sensor and the access mode of the node are Bluetooth, the node converts a Bluetooth protocol into an LoRa protocol.

Furthermore, 1-2 gateways are uniformly installed in each 20 floors, the gateways are connected to the internet through a wired network or mobile communication, and data transmitted by the nodes are transmitted to the cloud.

Further, the third-party application server side calls data from the cloud side through an API (application programming interface).

The invention also provides a building ad hoc network communication method based on LoRa-Mesh, which comprises the following steps:

1) the building communication system based on LoRa-Mesh is arranged in a building;

2) continuously supplying power to the node and the gateway;

3) the nodes and the gateway continuously receive the data transmitted from the sensor, and when the communication between the nodes or between the nodes and the gateway is blocked and the link is abnormal, a new communication link is searched again through an RPL (resilient packet layer) routing protocol to realize ad hoc network;

4) the gateway transmits the data to the cloud end through a network, and the cloud end distributes the data to the corresponding third-party application server side.

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

1. the contradiction between the indoor distribution and the reliable communication of the Internet of things is solved;

2. the monitoring problems of the node access quantity and the node state are solved;

3. a network architecture having security;

4. solves the flexible access problem of the third party equipment in the building

5. The system is a completely open network platform and has strong compatibility;

6. and a plug-and-play mode is adopted, so that the system is extremely convenient to construct and maintain.

In addition, the invention enables the protocol of the sensor to be converted from LoRa to Bluetooth, the cost of the Bluetooth sensor is lower, and the service life is longer (because the power consumption is lower); and the RPL protocol is adopted, so that the gateways can communicate with each other, the networking is automatic, and the construction and maintenance cost is reduced.

Drawings

FIG. 1 is a block diagram of a building communication system according to the present invention;

FIG. 2 is a schematic diagram of a building communication system provided by the present invention deployed in a building;

FIG. 3 is a distribution diagram of sensors and nodes in a building floor;

fig. 4 is a schematic diagram of data transmission in a building communication system.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, the present invention provides a building communication system based on LoRa-Mesh, including a sensor, a node, a gateway, a cloud and a third party application server, where the sensor is used to send data collected from a third party device in a building to the node, and the sensor includes a LoRa sensor and a bluetooth sensor (in fig. 1, the sensor in the smart door magnet and the wireless smoke sensor is a LoRa sensor, and in the mobile phone, the bluetooth sensor is a bluetooth sensor); the nodes are distributed in each floor of the building and used for transmitting data to the gateway, at least one node is deployed in each floor, the access mode of the sensor and the node is LoRa or Bluetooth, and when the access mode of the sensor and the node is Bluetooth, the node converts the Bluetooth protocol into the LoRa protocol; the gateways are arranged at certain positions according to the height of the building, for example, 1-2 gateways are uniformly installed in every 20 floors, the gateways are connected to the internet through a wired network or mobile communication, and data transmitted by the nodes are transmitted to the cloud. The cloud end is intensively deployed on the common cloud and used for distributing the data to the corresponding third party application server side outside the building through the API according to the characteristics of the data message.

Networking process: referring to fig. 2 and 3, gateways are reasonably installed according to the positions of floors in a building, and 1-2 gateways are installed in 20 floors generally. 1 or more nodes are installed on each floor, the nodes are reasonably distributed according to the size of the environment in the building, and all Bluetooth sensors can communicate with the nodes.

The specific functions of each part of the system are described as follows:

a sensor: the sensor may be a LoRa or bluetooth sensor. The Bluetooth sensors are general devices, the sensors using a standard Bluetooth protocol can be accessed to the network, and according to the characteristics of message messages, network operators can accurately transmit the information of the sensors to a designated processing server of the Internet of things. Since the bluetooth protocol is low power, the sensors can be battery powered, often for years or even longer.

And (3) node: there may be two access modes, LoRa and bluetooth. If the Bluetooth receiving sensor is used for accessing, due to the limitation of a Bluetooth protocol, the number of nodes and the number of sensors cannot exceed 20 meters generally, 1 node is required to be deployed in each floor generally, and more nodes are required to be deployed in buildings with larger flat areas. The main functions of a node include:

1. the Bluetooth protocol of the sensor is converted into an LoRa protocol, and data are transmitted to the gateway. The integrated circuit in the node removes the encapsulation of the Bluetooth protocol from the data transmitted by the Bluetooth channel, and transmits the data from the Lora channel in addition to the encapsulation of the Lora protocol.

2. The ad hoc network adopts Mesh technology, can communicate and form links among all nodes by modifying a routing protocol, and can automatically repair and connect roundly when part of the nodes are damaged.

A gateway: according to the size of an actual building or a park, 1 to a plurality of gateways are selected and deployed, the gateways are pre-configured by a network operator and are placed in a weak electricity computer room at the central position of the building, and the gateways are connected to the Internet by using a wired network or mobile communication (such as 4G and 5G).

The main functions include:

1. and (4) networking management, wherein the gateway communicates with the nodes by using an LoRa protocol, commands the nodes to automatically network and registers related information to the cloud.

2. And the communication channel is converted, and the gateway transmits the data transmitted by the node to the cloud end through a wired network or 4G and 5G.

Cloud: the method is characterized in that the method is intensively deployed on public cloud, operators are responsible for operation and maintenance, the method is generally built according to regions or industries, and the main functions comprise:

1. configuring and managing gateways and nodes by an operator; and the business unit calls data through the API interface to develop application.

2. Data distribution, which provides relevant data for users of the service according to the characteristics of the data packet, such as: sensor data from A, B is transmitted separately to A, B, but data from A, B are isolated from each other. Or sending data according to the area, such as transmitting the data of all fire-fighting sensors in the area to the fire department in the area.

Referring to fig. 4, the building ad hoc network communication method based on LoRa-Mesh includes the following steps:

1) the building communication system based on the LoRa-Mesh is arranged in a building;

2) continuously supplying power to the nodes and the gateway;

3) the nodes and the gateway continuously receive data transmitted from the sensor, and when the communication between the nodes or between the nodes and the gateway is blocked and a link is abnormal, a new communication link is searched again through an RPL (resilient packet link) routing protocol to realize ad hoc network;

4) the gateway transmits the data to the cloud end through the network, and the cloud end distributes the data to the corresponding third-party application server side.

The building communication system based on LoRa-Mesh is friendly to third-party access equipment and can transparently transmit, and as long as the definition of the communication system is complied with, the sensor data can be transmitted to a designated server according to the method shown in figure 2. All legitimate third party device sensors will automatically join as long as they are compatible with the BLE specifications.

The system adopts a low-power-consumption IPv6 routing protocol and a lossy network RPL communication protocol to construct an LoRa mesh network, and the network can be completely connected with each device to provide ubiquitous connection for the whole building.

RPL relies on IPv6 on low power WPAN (6LowPAN) to access a large number of devices through IPv6 addresses. RPL builds a destination-oriented Directed Acyclic Graph, DAG Graph (Directed Acyclic Graph), using the expected transmission number (ETX) as a metric to efficiently connect each device. Because the network topology is maintained automatically, the use of the RPL protocol ensures that there is no single point of failure of the network. However, RPL is originally dedicated to low-power-consumption and energy-limited devices, and these devices are in a sleep state when unnecessary for saving power, and there is no Keep-live heartbeat message. Even if the RPL protocol is available, the reliability of data transmission cannot be effectively guaranteed only by means of the RPL protocol due to link failure caused by environmental changes.

In contrast to the traditional low power consumption wireless sensor network arrangement, the gateway designed by the invention needs to be continuously powered. Therefore, the present system optimizes the RPL protocol in terms of duty cycle and parameter settings for better end-to-end reliability. Specifically, in the proposed system, the nodes do not sleep (i.e. 100% duty cycle), so that they can continuously listen to the wireless environment to receive packets, the LoRa radio continuously transmits data at inherently low speed, and if a link abnormality occurs and a heartbeat message is lost between the nodes, a new routing (finding an available link) action is immediately performed, and failed data is retransmitted. This enables the network provided by the present invention to provide an ad hoc and self-healing capability, enabling devices to maintain the most efficient network topology according to the current environment.

In addition, the system can solve the monitoring problems of the node access quantity and the node state:

the most advantage of the narrow-band communication network is that the communication distance is long, and the point-to-point communication can reach 10 kilometers in an open area. The wider the coverage, the more nodes that theoretically need to be accessed. However, a major disadvantage of narrowband communication is that the communication rate is low, the signal duty cycle is high, and the number of access nodes is greatly limited because the data allowed to be transmitted is limited within one day. In the face of the contradiction between long-distance large-area coverage and low-speed networks, the networking technology of the invention can cover a building with dozens of floors and a space of 100 meters around the building under one gateway. By reducing the signal power, the signal interference between buildings is greatly reduced, and the problem of the quantity of the access equipment of the Internet of things is effectively solved on the physical level. One gateway can easily access tens of thousands of Internet of things devices, can collect data at any place of a building, can increase or decrease the gateway at any time according to the number of access points, and solves the problem of data access.

The system of the invention also has the functions of monitoring the state of all the accessed nodes, giving an alarm in time when a fault occurs and ensuring the normal operation of the whole network.

Thirdly, the system provided by the invention has strong security of network architecture

The gateway and the server communicate with each other by using MQTT (message queue telemetry transport) protocol. The server-generated certificate, as each gateway must have credentials to access the server, while all traffic to and from the server must be encrypted by Transport Layer Security (TLS). For data on the cloud, it is guaranteed by the security mechanism of the cloud service provider.

The communication between the gateway and the node adopts remote (LoRa) technology, uses Preset Shared Key (PSK) scheme, and adopts 128-bit high-strength AES algorithm encryption for full flow.

For a third party device to join using bluetooth, its communication is only required to be fully compliant with the Bluetooth Low Energy (BLE) specification. If the application is special, pairing can be established, and a temporary session key (AES128) is generated between the two devices.

All data are finally stored in the cloud server, and the nodes and the gateways do not store data, so that the risk of data leakage does not exist.

Fourthly, the Bluetooth technology solves the flexible access problem of third-party equipment in the building:

compared with an LoRa sensor, the Bluetooth sensor has the characteristics of low price and lower power consumption, so that the construction cost of the network is lower than that of the network which completely adopts the LoRa sensor, and meanwhile, third-party equipment with the Bluetooth function is widely applied, any application equipment with a Bluetooth communication module can be freely accessed into the network, and plug-and-play LoRa nodes which are uniformly distributed are utilized to form short-distance Bluetooth wireless coverage. The user can not be locked by a hardware manufacturer at all, and can freely select hardware to flexibly access the network.

Fifth, the system provided by the present invention is a completely open network platform:

compatible with technical specifications of LoRa and Bluetooth, the existing terminal equipment conforming to the LoRa and the Bluetooth can be accessed, and the data of the terminal equipment is a cloud platform established on a public cloud.

Sixthly, the system is extremely convenient to construct and maintain:

the plug-and-play mode is adopted, so long as the nodes are reasonably deployed according to the situation of the field environment during engineering construction, the nodes are automatically connected with the equipment sensors to be managed, data are transmitted to the gateway through the LoRa network in the building, and the operation can be carried out by configuring the data at the cloud. In addition, the system can monitor each node in real time, if the node fails, the node can be separated from the network and send an alarm in time, but the whole network can still run normally, so that the maintenance work is very convenient.

Claims

1. Building communication system based on loRa-Mesh, its characterized in that is including sensor, node, gateway, high in the clouds and third party application server, wherein:

the sensor is used for sending data collected from third-party equipment in the building to the node, and comprises an LoRa sensor and a Bluetooth sensor;

the nodes and the gateways are continuously powered by a power supply, the communication protocol of the nodes and the gateways is LoRa, the routing protocol is RPL, and Mesh networks are automatically formed among different nodes and among the nodes and the gateways through the RPL.

2. The LoRa-Mesh based building communication system of claim 1, wherein at least one of the nodes is deployed in each floor, and the access mode between the sensor and the node is LoRa or Bluetooth.

3. The LoRa-Mesh-based building communication system of claim 2, wherein when the access mode of the sensor and the node is Bluetooth, the node converts the Bluetooth protocol into the LoRa protocol.

4. The LoRa-Mesh based building communication system of claim 1, wherein 1-2 said gateways are installed in every 20 floors, and the gateways are connected to the Internet through a wired network or a mobile communication, and transmit data transmitted from the nodes to the cloud.

5. The LoRa-Mesh based building communication system of claim 1, wherein the third party application server calls data from the cloud through an API interface.

6. A building ad hoc network communication method based on LoRa-Mesh is characterized by comprising the following steps:

1) arranging a LoRa-Mesh based building communication system according to claim 1 in a building;

2) continuously supplying power to the node and the gateway;

4) the gateway transmits the data to the cloud end through the network, and the cloud end distributes the data to the corresponding third-party application server end.