Three working modes of wifi

Three working modes of wifi

Three working modes of wifi, WIFI wireless routers are very popular and have a wide range of applications, especially now home Internet applications are even more essential. Now Nowadays, which one can use only one computer? Let’s share the three working modes of wifi. The three working modes of wifi 1

The first one: Ad-hoc (IBSS) mode

Ad-hoc, also known as independent basic service set, is used to create a wireless network. There is no hotspot (AP) required in this network. The status of each node in this network is equal. This mode is used to Connect several computers that cannot communicate through the base station. The ad-hoc mode is the same as the previous direct-connect twisted pair concept. It is a P2P connection, so it cannot communicate with other networks. Generally, wireless terminal equipment such as PMP, PSP, DMA, etc. use ad-hoc mode.

Everyone knows that the easiest way to set up a home wireless LAN is to implement wireless interconnection between two computers equipped with wireless network cards. If one of the computers is connected to the Internet, it can enjoy the bandwidth. Ad-Hoc structure is a peer-to-peer network structure that eliminates the need for wireless APs. As long as computers equipped with wireless network cards can achieve wireless interconnection with each other, the principle is that a computer host in the network establishes a point-to-point connection. It is equivalent to a virtual AP, and other computers can directly connect and share the network through this point-to-point connection.

Due to the elimination of wireless AP, the network setup process of Ad-Hoc wireless LAN is very simple. However, the transmission distance of general wireless network cards in indoor environments is usually about 40m. When this effective transmission distance is exceeded, Communication between each other cannot be achieved; therefore, this mode is very suitable for some simple or even temporary wireless interconnection needs.

Second type: WDS mode

The full name of WDS is Wireless Distributed System. In the past, in the field of wireless applications, it was a system that helped wireless base stations communicate with each other. The function of WDS is to act as a repeater for the wireless network. By turning on the WDS function on the wireless router, it can extend the wireless signal to cover a wider range. WDS allows wireless APs or wireless routers to bridge (relay) wirelessly without affecting the coverage effect of their wireless devices during the relay process. In this way, we can use two wireless devices to establish WDS trust and communication relationships between them, thereby expanding the wireless network coverage to more than double the original range, which greatly facilitates our wireless Internet access.

The third type: mesh mode

The Mesh interface enables dynamic routing between devices to achieve communication. In a wireless Mesh network, any wireless device node can serve as an AP and a router at the same time. Each node in the network can send and receive signals, and each node can communicate directly with one or more peer nodes. The biggest benefit of this structure is that if the nearest AP is congested due to excessive traffic, the data can be automatically rerouted to a neighboring node with smaller communication traffic for transmission. By analogy, the data packet can also continue to be routed to the next nearest node for transmission according to the network conditions until it reaches the final destination. This access method is multi-hop access. Three working modes of wifi 2

1. Transparent transmission mode

USR-WIFI232-A/B/C module supports serial port transparent transmission mode, which can realize serial port plug-and-play. Thereby minimizing the complexity of user use. In this mode, all data that needs to be sent and received is transparently transmitted between the serial port and the WiFi interface without any analysis.

In transparent transmission mode, it is fully compatible with the user's original software platform. User equipment can support wireless data transmission without making any software changes.

Transparent transmission mode is the least complex data transmission. Users also turn on the hardware flow control (CTS/RTS) function of the serial port, which can minimize the bit error rate.

If the user does not need the hardware flow control function of the serial port, he only needs to leave the corresponding pin (CTS/RTS) unconnected.

2. Serial port command mode

In this mode, users can send serial port data to different server addresses. In this mode, udp or tcp client can be used to send data to the server. .

The client MCU sends the data packet according to the following format. After the module parsing is completed, only n bytes of data are sent to the target address. When data is returned, the data is output directly from the serial port without parsing.

3. GPIO mode

High-performance WIFI module supports GPIO mode. In GPIO mode, the 4 pins of UART are defined as GPIO, nReady, and nLink are also defined as GPIO.

When the module works in GPIO mode, PC or other network devices can establish a connection (TCP/UDP) with the module through WIFI, and then control GPIO or read GPIO status through commands. The command is as follows:

GPIO n IN: Set GPIOn as input, return GPIO OK or GPIO NOK

GPIO n OUT 0: Set GPIOn as output low level, return command OK or command NOK

GPIO n OUT 1: Set GPIOn to output high level, return command OK or command NOK

GPIO n SW: Set GPIOn to output and change the original high and low level state, Return GPIO OK or GPIO NOK

GPIO n PWM m1 m2: Set GPIOn to output a level that changes from high to low, m1 is the high level time, m2 is the low level time (time unit ms, minimum 10 ms ), returns GPIO OK or GPIO NOK

GPIO n GET: Read GPIOn status, return I0, I1, O0, O1 respectively indicating input low, input high, output low, output high.

Note: n can be 3, 4, 5, 6, 8, 9, corresponding to the module pin. Among them, GPIO 4 can only be used as input, and GPIO 3 can only be used as output.

GPIO READ returns the status of all current IOs, which is consistent with the representation method of GPIO n GET. For example, I1I1I0I0I0I0O1, I represents input and O represents output. 0 means low, 1 means high.

4 This pin is inverted. Reading 1 is actually 0, reading 0 is actually 1. Three working modes of wifi 3

1. Hotspot mode (Access Point).

This mode is a typical working mode in the early days of WIFI wireless routing. The configuration of WIFI wireless router in this mode is relatively simple, just configure the wireless SSID and security policy. At this time, this machine does not have routing function and is purely equivalent to a switch with wireless access function. It can realize LAN access of multiple devices, both wired and wireless. In order to avoid DHCP conflicts with front-end network equipment, the DHCP function of the local machine is usually turned off. The IP address and DNS address of the user device need to be manually configured or automatically assigned through DHCP on the front end. The wired interface in this mode is the LAN port. This mode is suitable for wireless access in business, hotels, schools and other environments.

2. Wireless routing mode (Router).

This mode is the typical working mode of WIFI wireless router in the home. In this mode, in addition to the access switch function, the machine also has a routing function. At this time, one of the wired ports should be a WAN port, which is used to connect to ADSL Modem or community wired broadband. The WAN port can use the PPPoE protocol to automatically log in to the Internet access provided by the ISP. Multiple user devices can access the local network through wireless or wired connections and enjoy Internet connectivity. In this mode, you need to configure the wireless SSID, wireless security policy, and WAN port connection method.

Usually the DHCP function of the machine needs to be turned on, and the IP addresses and DNS addresses of all accessed user equipment are automatically assigned through the DHCP of the machine. This mode is suitable for: Internet sharing in homes, apartments and other environments.

3. Repeater mode.

This mode is used to expand the wireless signal coverage of hotspot AP access or wireless routing access mode. This mode requires the device to support WDS (Wireless Distribution System). It uses the wireless relay function of the device to relay and amplify wireless signals and form a new wireless coverage area, ultimately extending the coverage of the wireless network. At this time, the SSID, security policy, and communication channel must be consistent with the front-end wireless routing. The wired and wireless access control in the network is basically determined by the front-end wireless routing. It is equivalent to extending the physical distance of the wireless or wired access range of the front-end wireless router. If the front-end router also supports WDS, seamless roaming of the wireless network can even be achieved. Of course, after turning on the WDS function, the bandwidth of the wireless connection will be halved. In order to avoid conflicts with the DHCP of the front-end wireless router, the DHCP function of the local machine is usually turned off. The IP address and DNS address of the user device need to be manually configured or automatically assigned through DHCP on the front end. This mode is suitable for large-area places that cannot be covered by a single wireless router.