What is ICT?
ICT is an abbreviation for “Information and Communication Technology” and refers to communication that utilizes communication technology. It is a general term for industries and services that use communication technologies such as the Internet and information processing.
Types of wireless communication
Classification by distance
Wireless communication technology depends on the communication distance
- Short-range radio
- Wireless PAN (Personal Area Network)
- Wireless LAN (Local Area Network)
- Wireless MAN (Metropolitan Area Network)
- Wireless WAN (Wide Area Network)
Classification by frequency band
Wireless communication can also be classified by frequency band. The frequency band is the frequency range of radio waves and is also called “frequency band” or “band.” The wider the frequency band, the more data can be transferred at one time, so the communication speed will be faster.
Such a wide frequency band and high-speed communication line is called “broadband,” Conversely, a narrow frequency band, and low-speed communication line are called “narrowband.”
Wi-Fi, Bluetooth, LTE, etc., are classified as broadband, and BLE, LPWA, etc., are classified as narrow band.
Typical communication method
From here, we will take up typical communication methods and explain the characteristics of each.
NFC
At this time, the transportation IC card and the ticket gate communicate with each other by NFC, and payment is made with the money charged on the IC card.
Bluetooth, BLE
Bluetooth is a type of wireless PAN and is a standard for communicating at a relatively short distance, such as several tens of meters. Various things such as keyboards, mice, and speakers communicate using Bluetooth and can be used wirelessly. Bluetooth is a communication method that consumes less power and can be used for a long time.
In addition, by performing “pairing” that recognizes the devices that communicate with each other, automatic connection is possible from the second time onward without making any settings, and you can use it immediately. Due to these characteristics, Bluetooth is often used in devices and gadgets that are used on a daily basis.
It was developed for the purpose of low power consumption and low cost. Bluetooth is broadband, while BLE is a narrow band. BLE is explained in the following article, so please see here for details.
Wi-Fi
Since wireless LAN is a Local Area Network, Wi-Fi is also a communication method used within the same range of networks within the same site or building. Wi-Fi has been developed so that large files, photos, videos, etc., can be transferred neatly in a short time. Therefore, it is characterized by high communication speed and high functionality.
On the other hand, the power consumption is also increased by that amount, and it is not suitable for long-term use because it is not connected to a power source. In recent years, Wi-Fi development has been promoted nationwide due to the need for information transmission and tourism in the event of a disaster, and the places where Wi-Fi can be used are expanding. You can use Wi-Fi at public transportation, cafes, convenience stores, and other Wi-Fi spots.
In addition, there is a global Wi-Fi community called FON, and if you are a member, you can use Wi-Fi at more than 23 million access spots in 150 countries around the world.
Introduction to Short Range devices
Over the past few years, the widespread adoption of short-range wireless connectivity standards has been one of the notable trends in the semiconductor market. In addition to Bluetooth, various Wi-Fi, and ZigBee, there are new standards such as Wibree / Bluetooth ULP and Ultra-Wideband.
When faced with the need to connect multiple devices wirelessly, serious designers will look through these standards for solutions. Still, the wireless standards currently available are not always optimal for the application’s requirements.
One of the reasons is that these standards are available worldwide and use 2.4GHz (no license required). There is increasing interest in the low UHF band due to the lack of coexistence issues and the low propagation distance for the power budget in the 2.4GHz band. Common frequencies are 868MHz and 433MHz in Europe, 902 to 928MHz in the United States, and 426MHz in Japan. These are usually collectively referred to as the sub GHz band and also include unlicensed bands below 1GHz. Due to the lack of radio standards below 1GHz, designers are trying to use their own physical layer (PHY) and communication protocol stack.
