What Is a Dual SIM GSM Phone?

The full name of GSM is: Chinese is a global mobile communication system, commonly known as "Global Communication", a digital mobile phone network standard developed by Europe. It was developed to allow a mobile phone network standard to be used by all parts of the world and let users use a mobile phone Can travel all over the world. The GSM system includes GSM 900: 900MHz, GSM1800: 1800MHz, and GSM-1900, 1900MHz and other frequency bands.

GSM phone

GSM full name :,

Frequency band: Dual-band mobile phone users can automatically switch between the GSM900MHz and DCS1800MHz frequency band network areas, and tri-band mobile phone users can also select the PCS1 900MHz frequency band in North America.

Support GPRS.

Display: single screen, dual screen.

Chinese input method: T9, Zi, etc.

Phonebook and call log: Phone numbers can be stored, and can be moved and copied between the phone and SIM card; you can search by name and location; display dialed, received, and missed phone numbers.

Incoming call alert: Different incoming calls use different alert tones, and different incoming calls flash with different colors of backlight.

Short message: Support SMS and enhanced short message (EMS), that is, support the input, storage, sending and receiving of short messages, broadcast short messages, short message service function settings and voice mail.

Call management: call time reminder, emergency call, call billing, multi-party call, call hold, call waiting, set local number restriction, call and fax, call forwarding, call restriction.

Phone settings: ringtone size settings, SIM card PIN1, PIN2 management, phone lock (4-8 digits), set time and date, network selection, ring tone, language selection, vibration selection, clamshell answering, automatic answering, arbitrary Key to answer, low voltage alarm.

Accessories: alarm, timer switch, world time, notepad, electronic dictionary, calculator, timer, stopwatch, game.

Infrared transmission: can exchange business cards or data.

Go online.

STK: Support Chinese SIM card value-added services.

MP3 playback, radio, physical video.

Recording, voice dialing.

Mobile phone standards mainly include GSM, CDMA, and 3G. Since the advent of the mobile phone, it has experienced the first generation of analog standard mobile phones (1G), the second generation of digital mobile phones (2G) such as GSM and TDMA, and the second generation

The voice of a GSM digital mobile phone is transmitted on the wireless channel after being digitized. It is not as easily interfered as an analog mobile phone, so the voice is clear and the interference is small during a call. However, because the digitized voice is transmitted, there is a disadvantage that the voice is somewhat distorted. The voice distortion of analog mobile phones is better than that of GSM digital phones. Relevant departments are studying the development of more advanced voice digital coding technology to reduce the voice distortion of GSM mobile phones.

CDMA digital network: CDMA is the English abbreviation of Code Division Multiple Access. It is a new and mature wireless communication technology developed on the branch of digital technology-spread spectrum communication technology. It can meet the market's high requirements for mobile communication capacity and quality. It has the characteristics of high spectrum utilization, good voice quality, strong confidentiality, low call drop rate, small electromagnetic radiation, large capacity, and wide coverage. Reduce operating costs.

Operators in the industry are working to increase the number of users in their systems, reduce the cost per user, create greater profits and actively strengthen market penetration. Code division multiple access technology is one of the digital communication technologies to solve this problem.

The advantages of GSM mobile phones are:

Efficient band utilization and greater network capacity

Simplify network regulation

Improve call quality

Increased confidentiality

Improve coverage characteristics

Increase user talk time

Soft volume and "soft" switching

Faster Internet