KR102667456B1 - Apparatus and Method for Designing LoRa Network Protocol without Network Server for Constructing Local Wireless IoT Network - Google Patents

Abstract

The present invention relates to wireless communication IoT protocol design technology applicable to wireless IoT networks, including version information of the protocol full text, node name information of devices performing data transmission and reception functions, network name information for device management, and messages for message identification. A step of generating a header containing ID information, TTL information that is reduced by 1 when passing through the hopper for message life cycle management, full text length information indicating payload length information, and a payload containing a user-defined full text message. By using the LoRa network protocol design method that does not require a network server for building a local wireless IoT network, including the step of creating a load, the low-power, long-distance communication function that is characteristic of the LoRa communication module is used to easily communicate between devices in a small scale. Cells can be easily built.

Description

Apparatus and Method for Designing LoRa Network Protocol without Network Server for Constructing Local Wireless IoT Network}

The embodiment relates to protocol design technology, and more specifically, to wireless communication IoT protocol design technology applicable to a wireless IoT network.

In general, demand for IoT is spreading globally across all industries. Existing IoT technology is designed for fast, real-time transmission of massive amounts of data, multimedia data, and requires a lot of resources and costs. As the Internet of Things spreads and demand increases, the need to build a low-cost IoT network is increasing.

In particular, in order to easily and conveniently build small wireless IoT communication networks for small and medium-sized businesses, there is an emerging need to design and develop protocols based on LoRa, a low-cost, low-power, long-distance wireless communication technology.

However, the amount of data collected from many sensor devices for IoT in most corporate sites is mostly very small, and in many cases it is not very urgent and needs to cover a large area, so for long-term data collection, LPWAN for low-power wide area communication is used. (Low Power Wide Area Network) technology is advancing.

LPWAN consumes so little power that it can last for several years even with a small battery, and can support long distances such as industrial or campus applications. Sigfox, LoRa, and NB-IoT are representative LPWAN technologies. In addition, LPWAN has low power and low transmission speed, so it is good for use in networks where sensors are scattered over a wide area. In particular, LoRa is a core wireless communication technology for the Internet of Things among LPWAN technologies.

Many small businesses or smart farms want to build a low-cost, low-power, long-distance wireless IoT network using small-scale IoT systems, but the existing technology (LoRaWAN) has limitations in that the network is complex and relatively expensive, making access difficult.

KR 10-2145009 B1 KR 10-2118254 B1

The present invention was derived from this technical background, and is an IoT wireless device that can easily transmit and receive between devices over long distances with low power while overcoming the difficulties and costs of LoRaWAN and limitations of WiFi (intervention of routers, transmission and reception distance limitation issues and complexity). The purpose is to propose a technology that can be implemented using LoRa wireless communication technology to easily build and maintain/repair an IoT system at low cost without relatively network knowledge.

In other words, we designed a wireless communication IoT protocol that can easily build a small-scale (FemtoCell: 1 to 300 nodes) cell with easy inter-device communication using the low-power, long-distance communication function of the LoRa wireless communication module for low-power, long-distance IoT. We want to provide the technology to do this.

In addition, we provide a LoRa network protocol design device and method that does not require a network server for building a local wireless IoT network that can compensate for the shortcomings of WiFi (communication distance problems) and LTE-CatM1 (management and economic problems) for IoT. It has a purpose.

The present invention for achieving the above problems includes the following configuration.

That is, the LoRa network protocol design method that does not require a network server for building a local wireless IoT network according to an embodiment of the present invention includes one processor and a memory that stores one or more programs executed by the one or more processors. In a method performed in a computing device, the version information of the protocol text, node name information of the device performing data transmission and reception functions, network name information for device management, message ID information for message identification, and message life cycle management are provided. In order to do this, it includes TTL information that is reduced by 1 when passing through the hopper, generating a header containing full text length information indicating payload length information, and creating a payload containing a user-defined full text message. .

Meanwhile, according to one embodiment, a LoRa network protocol design device that does not require a network server for building a local wireless IoT network includes one or more processors and a memory that stores one or more programs executed by the one or more processors. As a computer device, it includes version information of the protocol text, node name information of the device performing data transmission and reception functions, network name information for device management, message ID information for message identification, and message passing through the hopper for life cycle management. It includes a header generation unit that generates a header containing TTL information reduced by 1, full text length information indicating payload length information, and a payload creation unit that creates a payload containing a user-defined full text message.

According to the present invention, a wireless communication IoT protocol that can easily build a small cell (FemtoCell: 1 to 300 nodes) with free communication between devices is designed and implemented using the low-power and long-distance communication functions that are characteristic of the LoRa communication module. This has the effect of providing a LoRa network protocol design device and method that does not require a network server for building a local wireless IoT network.

In addition, we will provide a LoRa network protocol design device and method that does not require a network server for building a local wireless IoT network that can compensate for the shortcomings of WiFi (communication distance problems) and LTE-CatM1 (management and economic problems) for IoT. You can.

Figure 1 is a block diagram showing the configuration of a LoRa network protocol design device that does not require a network server for building a local wireless IoT network according to an embodiment of the present invention.
Figure 2 is an exemplary diagram illustrating a LoRa network protocol structure for building a small-scale local wireless IoT network according to an embodiment of the present invention.
Figure 3 is an overall configuration diagram of the LoRa network protocol for building a small and medium-sized local wireless IoT network according to an embodiment of the present invention.
Figure 4 is an exemplary diagram of an IoT network configuration configured with the LoRa network protocol according to an embodiment of the present invention.
Figures 5A to 5E are exemplary diagrams showing a method of two-way communication between devices or a two-way communication method through a gateway between a device and a server in an IoT network configured with the LoRa network protocol according to an embodiment of the present invention.
Figure 6 is an example diagram of a sensor monitoring system using the LoRa network protocol for building a small and medium-sized local wireless IoT network according to an embodiment of the present invention.
Figure 7 is a flowchart of a LoRa network protocol design method that does not require a network server for building a local wireless IoT network according to an embodiment of the present invention.

It should be noted that the technical terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention, unless specifically defined in a different sense in the present invention, should be interpreted as meanings generally understood by those skilled in the art in the technical field to which the present invention pertains, and are not overly comprehensive. It should not be interpreted in a literal or excessively reduced sense.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

The LoRa network protocol design device that does not require a network server for building a local wireless IoT network according to embodiments of the present invention can be implemented by at least one computer device, and can be implemented by at least one computer device, and the local wireless IoT network according to embodiments of the present invention. The LoRa network protocol design method that does not require a network server for construction can be performed through at least one computer device included in the LoRa network protocol design device that does not require a network server for construction of a local wireless IoT network. At this time, a computer program according to an embodiment of the present invention may be installed and driven in the computer device, and the computer device may operate a network for constructing a local wireless IoT network according to embodiments of the present invention under the control of the driven computer program. A server-free LoRa network protocol design method can be performed. The above-described computer program can be combined with a computer device and stored in a computer-readable recording medium to enable the computer to execute a LoRa network protocol design method that does not require a network server for building a local wireless IoT network.

Figure 1 is a block diagram showing the configuration of a LoRa network protocol design device that does not require a network server for building a local wireless IoT network according to an embodiment of the present invention.

According to one embodiment, the LoRa network protocol design device 10, which does not require a network server for building a local wireless IoT network, applies LoRa technology to build a low-cost and optimized IoT network to build a simple IoT LoRa LAN. Implementing IoT LPLAM and IoT LPWAN Network, it implements radio wave hopping (TTL) function when the communication environment is poor or a wider section needs to be grouped into the same section, and LoRa CoCoNET Gateway function for Internet access (granting of MessageID, duplication) message removal), and can enable simple professional transmission and reception functions between nodes using naming method without gateway intervention.

Accordingly, the LoRa network protocol development technology for building a small and medium-sized local wireless IoT network according to one embodiment reduces the complexity of the existing LoRaWAN technology, enabling a simple and low-cost network configuration.

That is, according to one embodiment, the LoRa network protocol design device 10, which does not require a network server for building a local wireless IoT network, uses LoRa, a low-cost, low-power, long-distance wireless communication technology, to easily and conveniently build a small wireless IoT network for small and medium-sized businesses. Based protocol design and development can be proposed. According to one embodiment, a simple and low-cost network configuration is possible by reducing the complexity of the existing LoRaWAN technology, and network construction becomes easier through the development of Device to Device wireless transmission and reception functions for Name and Role-based devices.

In addition, although it is a protocol for small-scale Local IoT (Femtocell) networks, network expansion is possible by applying hopping technology, and it is possible to configure a small- to medium-sized LoRa network (100 to 300 devices) independent of the telecommunication company.

According to one embodiment, a LoRa network protocol design device that does not require a network server for building a local wireless IoT network can design and implement a protocol that can support layers 2 to 4 of OSI 7 Layer.

As shown in FIG. 1, the LoRa network protocol design device 10, which does not require a network server for building a local wireless IoT network according to an embodiment, includes version information of the protocol text, node name information of the device performing the data transmission and reception function, and device management. A header that generates a header containing network name information for message identification, message ID information for message identification, TTL information that is reduced by 1 when passing through the hopper for message life cycle management, and full text length information indicating payload length information. It includes a creation unit 110 and a payload creation unit 120 that creates a payload containing a user-defined professional message.

According to one embodiment, a LoRa network protocol design device that does not require a network server for building a local wireless IoT network uses long-distance LoRa wireless communication technology for low-cost, low-power IoT. And for small and medium-sized businesses and smart farms, it is possible to design devices and protocols that are easy to manage and configure and can apply IoT technology at low cost.

According to one embodiment, the LoRa network protocol design device 10, which does not require a network server for building a local wireless IoT network, performs the Device to Device wireless transmission and reception function of Name and Role-based devices and supports small-scale Local IoT (Femtocell: 1 to 300). ) network, but it is possible to expand the network by applying hopping technology, and it is possible to configure a small to medium-sized LoRa network (100 to 300 devices) independent of the telecommunication company.

The LoRa network protocol design device 10, which does not require a network server for building a local wireless IoT network according to an embodiment, designs wireless settings such as wireless channel, transmission power, SF, and bandwidth.

The header generator 110 further includes hopper name information for performing a transmission function to a neighboring LoRa network according to hopper information preset for transmission to a neighboring network.

Additionally, the header generator 110 generates a header portion of a fixed length. In one embodiment, the head part generated by the header generation unit 110 includes a 4-byte long Node Name including the protocol version and a 4-byte long Network Name, an item for ACK transmission, and a Message for uniqueness of the message. It consists of id, TTL for message life.

And the header generator 110 further includes gateway name information for the gateway device to perform a transmission function to the Internet network according to preset Internet information.

The payload creation unit 120 creates a payload containing a user-defined professional message. The payload creation unit 120 contains data or information transmitted to achieve the purpose and provides data to the web application. It may include information used to receive or perform operations, or data used for malicious code or hacking attacks in the security field.

Figure 2 is an exemplary diagram illustrating a LoRa network protocol structure for building a small-scale local wireless IoT network according to an embodiment of the present invention.

As shown in FIG. 2, the protocol structure according to one embodiment may be implemented as a protocol packet structure of OSI 7 Layer 3 to 4 layers.

As shown in Figure 2, the protocol can be divided into a head part and a payload area. The protocol head area is based on a fixed length, and the payload area is set according to the device business function.

Specifically, the protocol head structure design is based on the definition design for each LoRa communication module function. It is implemented to design roles for each role-based device function. It is implemented as a name-based device, and node and network concepts for 1:1, 1:N, and N:1 are applicable, and includes sensor terminals, actuator terminals, gateways, and hoppers. .

In addition, message life cycle function (TTL), unique function using message ID, ACK function to ensure transmission, physical network separation using channel and logical network separation function using network group, payload length according to LoRa wireless settings. Setting functions can be performed.

The LoRa network protocol design device 10 for building a small-scale local wireless IoT network according to an embodiment includes wireless setting function design, API design according to protocol function, transmission/reception channel setting in the device, No ACK Device, and ACK Device (Actuator). , Set TTL, ACK, MSG-ID, SendTo A Device, Recv From A Device, SendTo A Group Device, Recv From Any protocol functions are designed.

Specifically, the head part of the LoRa network protocol for building a small-scale local wireless IoT network according to an embodiment of the present invention includes a 4-byte long Node Name and a 4-byte long Network Name including the protocol version. It includes items for ACK transmission, Message id for message uniqueness, and TTL for message life.

The full text version of the protocol is located first within the Head item. And since the node name is defined based on the role of the device used in IoT communication, the device must have a unique name within the network (or group), and the Send/Recv function is performed by specifying the name in the API to be implemented.

Logically, a network name must be specified to manage the device, and it includes the network name uniquely set in the entire project. Then, the Send/Recv function is performed by specifying the name in the API to be implemented.

ACK Flag is a flag that specifies whether to receive an Ack after transmission, and Message ID is the only ID information used to identify the message set at the time of message creation. This is used for future message deduplication. TTL information manages the life cycle of the message and decreases by 1 when it passes through the Hopper and is destroyed when it reaches 0. The length of the full text is the length of the user's payload according to the full text, and the payload is implemented as a full text message according to the user's convenience.

According to one embodiment, the LoRa network protocol design device that does not require a network server for building a local wireless IoT network corresponds to LoRa protocol development and designs a protocol that can support layers 2 to 4 of OSI 7 Layer.

The OSI 7 Layer 2nd layer protocol according to the LoRa Packet structure is currently implemented using the Semtech LoRa SX1276 Transceiver Chip, and the implementation is implemented as a Low Level API through the SX1276 Register map.

The low level API consists of functions that manipulate the three digital interfaces of the Semtech LoRa SX1276 Transceiver, such as Configuration Register, Status Register, and FIFO Data Buffer.

And the most important wireless parameters for wireless settings in the Low level API include Frequency, Signal Bandwidth, Spread Factor, and Cording Rate.

Table 1 is an example diagram of a LoRa KR920 frequency table according to an embodiment.

The table shown in Table 1 is the KR920 frequency table available for LoRa communication, and a total of 13 channels can be used.

Center frequency (MHz) Bandwidth(kHz) Maximum EIRP output power(dBm) for end-device For gateway 920.9 125 10 23 921.1 125 10 23 921.3 125 10 23 921.5 125 10 23 921.7 125 10 23 921.9 125 10 23 922.1 125 14 23 922.3 125 14 23 922.5 125 14 23 922.7 125 14 23 922.9 125 14 23 923.1 125 14 23 923.3 125 14 23

Figure 3 is an overall configuration diagram of the LoRa network protocol for building a small and medium-sized local wireless IoT network according to an embodiment of the present invention, and Figure 4 is an example diagram of an IoT network configuration composed of the LoRa network protocol according to an embodiment of the present invention.

According to one embodiment, the LoRa wireless communication technology is an IoT wireless technology that can easily transmit and receive between devices over long distances with low power while overcoming the difficulties and costs of LoRaWAN and limitations of WiFi (intervention of routers, transmission and reception distance limitation issues and complexity). By using this method, LoRa network protocol development technology can be derived for building a small to medium-sized local wireless IoT network that can easily build and maintain/repair an IoT system at low cost without relatively network knowledge.

In addition, due to the limitations of the complex architecture of small and medium-sized LoRaWAN and small-scale local LoRa networks, a simple LoRa (Femtocell) network configuration protocol that does not require a LoRaWAN network server can be designed.

Accordingly, by utilizing the advantages of LoRa communication, a low-power, long-distance IoT network can be easily built, and the costs of construction and maintenance are greatly reduced. In addition, since wireless communication between devices is possible without a WiFi router or gateway, transmission and reception between devices according to work can be easily implemented.

According to one embodiment, 1 to 300 (Femtocell) devices can be connected to one gateway, which is advantageous in terms of technology and cost over wired work, and can easily transmit and receive between IoT devices based on role and name. The effect is that it is easy to manage without specialized knowledge. Since IoT is applied to all industrial fields, it becomes easier to build an IoT system and social and economic costs can be reduced.

As shown in FIG. 4, an IoT network composed of the LoRa network protocol according to an embodiment is composed of IoT devices based on their roles.

It includes a Oneway Device that transmits simple measurement data and ACK, an Actuator Device that receives and executes commands from other devices and transmits an active Device ACK, a Gateway Device for Internet connection, and a Hopper Device that performs network expansion by channel separation. .

Oneway Device wakes up only during the transmission period to minimize power consumption, and enters sleep mode to save power at other times. Other devices must always be on standby for reception, so they are in a wake up state and are waiting for reception.

Each Device has a unique name and belongs to a logical Network group.

This allows communication between devices without the need for a relay device, communication between devices without the intervention of a WiFi router, LoRaWAN network server, or gateway, and wireless communication can be easily performed using the device name without the existing relay or management device for communication between devices. possible. Accordingly, 1:1, 1:N, and N:1 communication functions can be performed.

Since each device has a name and group, it can perform 1:1 function or group broadcast communication function, and supports AES128 encryption function.

Devices can communicate with each other by Device Name without gateway relay, and if necessary, they can use the messages Ack Request and Ack Response to ensure message transmission.

And when a message via the Internet is sent with the destination set to the Gateway Name, the Gateway Device transmits it to the Internet network according to the preset Internet information. Internet communication can be a client of TCP, UDP, MQTT, COAP, etc. implemented in the gateway.

Additionally, when transmitting to another neighboring network, the Hopper Name is used as the destination, and the Hopper Device transmits (Relay: channel change) to the neighboring LoRa network according to the preset Hopper information.

In one embodiment, there are a total of six LoRa Data Rates from DR0 to DR5, and the LoRa terminal selects one of the six DRs to operate. Spreading Factor, Maximum Data Rate, and Maximum Application Payload Size for each DR can be shown in Table 2.

Data Rate Spreading Factor Max. Data Rate Max.Application Payload DR0 SF12 293bps 65bytes DR1 SF11 537bps 151bytes DR2 SF10 977bps 247bytes DR3 SF9 1.76kbps 247bytes DR4 SF8 3.13kbps 247bytes DR5 SF7 5.47kbps 247bytes

According to one embodiment, the burden of communication costs can be reduced, and a self-IoT network can be built at a lower cost than LoRaWAN. Network configuration is simplified because there is no network server essential for LoRaWAN, and since it is a self-network, maintenance is performed by unifying the management scope. It also becomes more convenient. Network expansion using Hopper is easy, and because communication coverage is wide, Internet connection is also easier. And simple transmission and reception between devices is possible without a gateway or network server.

In addition, stable collection of sensor data wirelessly is possible even in places where various facilities are gathered. Sensor devices are wireless and battery-based, so they do not require complicated cable work, making them very convenient to install and move. Data from hundreds of sensor devices (about 100 to 300) installed in a wide area can be collected reliably with one gateway. LoRa is a wireless communication that enables communication between floors of a building and long-distance (5 km) communication, and since the network can be expanded using Hopper, it can be expanded to dozens of km.

In addition, since the network server essential for LoRaWAN is not required, network configuration is simplified, maintenance is convenient, and it is possible to build an own IoT network at a lower cost than LoRaWAN.

In addition, since it is a private network, maintenance is convenient due to the unification of the management scope, AP connection settings for communication, which are essential in the case of wifi, are not required, sensor device settings are not required, the device is automatically connected to the gateway when installed, and it is cheaper than LoRaWAN. It can be implemented at cost.

Figures 5A to 5E are exemplary diagrams showing a method of two-way communication between devices or a two-way communication method through a gateway between a device and a server in an IoT network configured with the LoRa network protocol according to an embodiment.

Specifically, this is an example showing a two-way communication method between devices in an IoT network, a two-way communication method with a server using a gateway, and a two-way communication method using Hopper.

Figure 5a is an example diagram showing 1:1 two-way communication between devices, Figure 5b is an example diagram showing 1:N two-way communication between devices, Figure 5c is an example diagram showing N:1 two-way communication between devices, and Figure 5d is an example diagram showing a method for two-way communication from a device to a server through a gateway. The server not only receives data from the device remotely through a gateway connected to the Internet or an internal network, but can also control the actuator terminal by sending data such as control commands to the device.

Figure 5e is an example diagram showing a method of 1:1 communication between remote devices outside the communication range of LoRa using Hopper. If you want to communicate 1:1 between devices at a distance, but the distance is too far to communicate directly, you can see the effect of network expansion by using Hopper, which performs a connection function between communication networks. This network expansion function using Hopper can be applied not only to 1:1 communication between devices, but also to 1:N and N:1 communication.

Figure 6 is an example diagram of a sensor monitoring system to which the LoRa network protocol is applied for building a small and medium-sized local wireless IoT network according to an embodiment.

As shown in FIG. 6, inter-node communication is possible between sensor devices to which the LoRa network protocol is applied for building a small and medium-sized local wireless IoT network according to an embodiment.

In other words, a private LoRa network can be configured, a network server is not required, and the number of gateway channels can be implemented as 1 channel. Additionally, network extension is possible through multi-hopping, and the application server can perform a message deduplication function. In addition, direct communication between devices is possible through the LoRa network protocol, enabling 1:1, 1:N, and N:1 communication and simplifying network configuration. In addition, it is implemented with a femtocell structure at low cost, and device and management can be performed through simple procedures.

Figure 7 is a flowchart of a LoRa network protocol design method that does not require a network server for building a local wireless IoT network according to an embodiment of the present invention.

According to one embodiment, a LoRa network protocol design method that does not require a network server for building a local wireless IoT network includes a computing device having one processor and a memory that stores one or more programs executed by one or more processors. This method is performed in the protocol full text version information, node name information of the device performing data transmission and reception functions, network name information for device management, message ID information for message identification, and passing through the hopper for message life cycle management. It includes TTL information decremented by 1 per hour, a step of generating a header portion including full text length information indicating payload length information (S710), and a step of creating a payload containing a user-defined full text message (S720). do.

In one aspect, the step of generating a header further includes hopper name information for performing a transmission function to a neighboring LoRa network according to hopper information preset for transmission to a neighboring network.

And the step of generating the header section generates a header section of a fixed length.

In addition, the step of generating the header part further includes gateway name information for the gateway device to perform a transmission function to the Internet network according to preset Internet information.

The above-described method may be implemented as an application or in the form of program instructions that can be executed through various computer components and recorded on a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc., singly or in combination.

The program instructions recorded on the computer-readable recording medium may be specially designed and configured for the present invention, or may be known and usable by those skilled in the computer software field.

Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, and magneto-optical media such as floptical disks. media), and hardware devices specifically configured to store and perform program instructions, such as ROM, RAM, flash memory, etc.

Examples of program instructions include not only machine language code such as that created by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform processing according to the invention and vice versa.

Although the above has been described with reference to embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the following patent claims. You will be able to.

10: Protocol design device 110: Header generation unit
120: Payload generation unit

Claims (5)

one processor, and
In a method performed on a computing device having a memory storing one or more programs executed by the one or more processors,
Version information of the protocol text, node name information of the device performing data transmission and reception functions, network name information for device management, message ID information for message identification, and message life cycle management, which is decreased by 1 when passing through the hopper. Generating a header portion including full text length information indicating TTL information and payload length information; and
Comprising: creating a payload containing a customized professional message,
The step of creating the header part is,
It further includes hopper name information to perform the transmission function to the neighboring LoRa network according to the hopper information preset for transmission to the neighboring network,
The step of creating the header part is,
A LoRa network protocol design method that does not require a network server for building a local wireless IoT network, further including gateway name information for the gateway device to perform a transmission function to the Internet network according to preset Internet information.
delete According to claim 1,
The step of creating the header part is,
A LoRa network protocol design method that generates a fixed-length header and does not require a network server for building a local wireless IoT network.
delete one or more processors, and
A computer device having a memory storing one or more programs to be executed by the one or more processors,
Version information of the protocol text, node name information of the device performing data transmission and reception functions, network name information for device management, message ID information for message identification, and message life cycle management, which is decreased by 1 when passing through the hopper. a header generation unit that generates a header unit including full text length information indicating TTL information and payload length information; and
It includes a payload creation unit that creates a payload containing a user-defined professional message,
The header generator,
It further includes hopper name information to perform the transmission function to the neighboring LoRa network according to the hopper information preset for transmission to the neighboring network,
The header generator,
A LoRa network protocol design device that does not require a network server for building a local wireless IoT network, further including gateway name information for the gateway device to perform a transmission function to the Internet network according to preset Internet information.