Wireless communication technologies within reach in daily life - WiFi, Bluetooth and NFC

WiFi

Wi-Fi (Wireless Fidelity) is a wireless LAN technology that uses wireless signals to connect devices and networks. Wi-Fi technology allows users to transfer data and access the Internet through wireless signals without the need for wired connections. Wi-Fi technology has become an indispensable part of modern life and is widely used in various occasions such as homes, offices, commercial places and public areas.

WiFi technology originated in 1997 and was invented by scientists from Australia's CSIRO (Commonwealth Scientific and Industrial Research Organisation). They used a technology called "OFDM" (Orthogonal Frequency Division Multiplexing) to successfully increase the data transmission speed to 2Mbps. This technology was later incorporated into the IEEE 802.11 standard and became the basis of WiFi technology.

Mainstream WiFi standards

1. 802.11b: One of the earliest WiFi standards, operating in the 2.4GHz band with a maximum transfer rate of 11 Mbps.
2. 802.11a: It is also an earlier WiFi standard, operating in the 5GHz frequency band with a maximum transmission rate of 54 Mbps.
3. 802.11g: Works in the 2.4GHz frequency band, with a maximum transmission rate of 54 Mbps and is backward compatible with 802.11b.
4. 802.11n: Supports 2.4GHz and 5GHz frequency bands, with a maximum transmission rate of 600 Mbps, and uses MIMO technology to improve transmission rate and coverage.
5. 802.11ac: Works in the 5GHz band with a maximum transfer rate of up to 1 Gbps, using more advanced technology to improve speed and performance.
6. 802.11ax (Wi-Fi 6): One of the latest WiFi standards, it supports 2.4GHz and 5GHz frequency bands, has higher transmission rates and better network capacity, and can better cope with high-density connection and data transmission needs.

WiFi Security

1. Use encryption: Enable WPA3 or WPA2 encryption to protect your wireless network. Avoid using WEP encryption as it is already insecure.
2. Change Default Credentials: Change the default usernames and passwords for your routers and Wi-Fi networks to use strong passwords and usernames.
3. Hide Network Name (SSID): Turn off Broadcast Network Name (SSID) to hide your network so only people who know the network name can connect.
4. Enable Firewall: Enable firewall on your router and connected devices to block unauthorized access and network attacks.
5. Update firmware: Update your router’s firmware regularly to fix security vulnerabilities and improve security.
6. Use a virtual private network (VPN): Use a VPN to encrypt data transmission when connected to public Wi-Fi to prevent data from being stolen.
7. Disable WPS: Wi-Fi Protected Setup (WPS) has security vulnerabilities and is recommended to be disabled to improve security.

These methods can help improve the security of your Wi-Fi network, but you also need to be careful to regularly check and update security settings to address new security threats.

Bluetooth

Bluetooth is a wireless technology used to transmit data over a short distance. It is commonly used to connect mobile phones, headphones, speakers, keyboards, mice and other devices. Bluetooth technology enables wireless communication and data transmission between devices.

Bluetooth originated in 1994 and was developed by Ericsson engineers Jaap Haartsen and Sven Mattisson. Initially, their goal was to develop a technology that could enable wireless communication between mobile phones and other portable devices. With the development of technology, Bluetooth has become a widely used standard for short-range wireless communication between various devices.

Common Bluetooth versions

1. 「Bluetooth 1.0 and 1.1」: The initial Bluetooth version with basic data transmission capabilities.
2. 「Bluetooth 2.0 + EDR」: Enhanced Data Rate (EDR) improves data transmission speed and efficiency.
3. 「Bluetooth 3.0 + HS」: Introduces High Speed ​​mode, supporting faster data transmission speeds and working with Wi-Fi.
4. 「Bluetooth 4.0」: Introduced Bluetooth Low Energy (BLE), which is suitable for low-power devices such as smart watches, health monitoring devices, etc.
5. 「Bluetooth 4.2」: Provides faster data transmission speed and stronger privacy protection.
6. 「Bluetooth 5.0」: Further improves data transmission speed and coverage, and supports multi-device connection and broadcasting functions.
7. 「Bluetooth 5.1」: Introduces positioning and orientation functions, which can achieve more accurate positioning and navigation.
8. 「Bluetooth 5.2」: Provides higher data transmission speed and lower power consumption, enhanced security and connection stability.

The development trend of Bluetooth technology

1. "Low power consumption": With the rise of the Internet of Things and wearable devices, the low power consumption requirements for Bluetooth devices are getting higher and higher, so the development of Bluetooth technology in low power consumption will be an important trend.
2. "High-speed transmission": With the launch of Bluetooth 5.0 and later versions, the transmission speed of Bluetooth technology will continue to increase, thereby better supporting applications such as high-definition audio and video transmission.
3. 「Mesh network」: The emergence of Bluetooth Mesh network enables Bluetooth devices to build larger-scale networks, which is suitable for scenarios such as smart homes and smart buildings.
4. 「Positioning and Navigation」: The development of Bluetooth positioning technology will make indoor positioning and navigation possible, providing more possibilities for indoor positioning applications.
5. "Security": With the increasing application of Bluetooth in payment, access control and other fields, the security of Bluetooth technology will become an even more important concern.

The development trend of Bluetooth technology will continue to move towards low power consumption, high-speed transmission, Mesh network, positioning navigation and security.

NFC

NFC stands for "Near Field Communication", which is a short-range wireless communication technology that allows devices to communicate without contact or at a very short distance. NFC is commonly used in the fields of mobile payment, access control systems, smart tags, etc. In NFC communication, devices communicate through radio waves, and the typical working distance is within a few centimeters.

NFC technology originated in 2002 and was jointly developed by Philips and Sony. It is based on RFID (Radio Frequency Identification) technology and can perform wireless communication and data transmission within a short distance. NFC technology was originally used in mobile payment, smart tags, and data transmission, and is now widely used in scenarios such as mobile payment, public transportation cards, and access control systems.

NFC operating modes

1. 「Reader/Writer Mode」: The device can read or write information from NFC tags or other compatible devices.
2. "Peer-to-Peer Mode": Two NFC devices can exchange information with each other for data transmission and sharing.
3. 「Card Emulation Mode」: The device can simulate an NFC card, allowing other NFC devices to read its information. It is often used in scenarios such as mobile payment and access control systems.

Common application scenarios of NFC

1. Contactless payments: NFC technology allows users to make contactless payments using their mobile phones or other devices, such as using mobile payment apps or bank cards.
2. Access control system: NFC technology can be used in access control systems. For example, company employees can use NFC cards or mobile phones for access control.
3. Transportation: NFC technology can be used to swipe cards to ride buses, subways and other means of transportation, which is convenient and fast.
4. Information transfer: NFC can be used to quickly transfer information, such as sharing photos, contact information and other data between two devices.
5. Electronic identity recognition: NFC technology can be used for identity recognition applications such as electronic ID cards and access cards.
6. Smart tags: NFC tags can be used for intelligent management of items. For example, NFC tags can be attached to items in stores to facilitate customers to obtain product information.

Comparison of WiFi, Bluetooth and NFC

• WiFi (Wireless Local Area Network): Used for wireless network connection, it can realize interconnection between devices and is often used for functions such as Internet access and file transfer.
• Bluetooth: A short-range wireless technology used for data transmission and communication between devices, commonly used to connect peripherals such as headphones, speakers, keyboards, and mice.
• NFC (Near Field Communication): A short-range, high-frequency wireless communication technology used for close-range data transmission and interaction, commonly used in mobile payments, access cards, bus cards, and other scenarios.