Telecommunications and mobile phones radiate a lot.

Telecom mobile phones have less radiation.

The following is an excerpt.

Code division multiple access (CDMA), also known as CDMA, is a technology for wireless communication. CDMA allows all users to use all frequency bands at the same time, treating signals sent by other users as noise, regardless of signal collision.

The advantages of CDMA include: the voice coding technology provided by CDMA is better than that provided by GSM, which can reduce the noise of the surrounding environment when users talk and make the conversation clearer. CDMA adopts spread spectrum communication technology, so it can reduce the interference between mobile phones and increase the capacity of users. Moreover, the power of the mobile phone can be relatively low, which can not only make the use time longer, but also reduce the harm of electromagnetic radiation to people. The bandwidth of CDMA can be greatly expanded and images can be transmitted, which is why the third generation mobile phone chooses CDMA. As far as security performance is concerned, CDMA not only has a good authentication system, but also greatly enhances the anti-eavesdropping ability by using code division multiplexing due to its transmission characteristics.

At present, CDMA system is developing rapidly. Wideband code division multiple access (WCDMA) broadband code division multiplexing transmission technology is an important basic technology of IMT-2000, which will become the standard of the third generation digital wireless communication system.

The full name of GSM is Global System for Mobile Communications, and Chinese is Global System for Mobile Communications, commonly known as "GSM". It is a digital mobile phone network standard developed in Europe. Its development purpose is to make all parts of the world use the same mobile phone network standard, so that users all over the world can use a mobile phone. The GSM system includes GSM 900:900MHz, GSM 1800: 1800 MHz, GSM- 1900MHz and GSM- 1900 MHz.

GSM system has several important features: good anti-theft ability, large network capacity, rich mobile phone number resources, clear call, strong stability, sensitive information, few dead ends and low power consumption of mobile phones. At present, the two main GSM systems in the world are GSM 900 and GSM 1800. Because the frequencies used are different, the applicable mobile phones are different. The former developed earlier and used more countries, while the latter developed later and used fewer countries. In terms of physical characteristics, the former has low frequency spectrum, long wavelength and poor penetration, but the transmission distance is long, while the mobile phone has strong transmission power, large power consumption and short standby time; The latter has higher frequency spectrum, shorter wavelength and better penetration, but its transmission distance is short, its mobile phone transmission power is small and its standby time is correspondingly long.