What's the number of the information center? I can't send text messages.

The coding rule of the service number of China Mobile SMS Center is: +86 1380+ four-digit long-distance area code of the account opening branch +500; if the long-distance area code is less than four digits, add "0" to complete it (for example, Beijing is +86 13800 100500). You can also call the local mobile service center at 1860.

The number of Beijing Unicom SMS Center is+86130112500, or you can call 100 1 for consultation!

Unicom CDMA mobile phone users can directly input and send short messages on their mobile phones without setting the number of the short message center.

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 technical standard of mobile communication originated in Europe, and it is the second generation of mobile communication technology. Its development purpose is to enable all parts of the world to use the same mobile phone network standard, so that users all over the world can use a mobile phone. China introduced this technical standard in the early 1990s, and has been using cellular analog mobile technology, that is, the first generation of GSM technology (China closed the analog mobile network on February 3, 20061day). At present, China Mobile and China Unicom each have a GSM network, which is the largest mobile communication network in the world. The GSM system includes GSM 900:900MHz, GSM 1800: 1800 MHz and GSM- 1900: 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.

Packet switched data network;

Packet-switched data network-a communication network for data exchange. It is suitable for communication between computers of different types and speeds, between computers and terminals, so as to realize the sharing of information resources stored in computers, and at the same time, it can carry out various value-added services on packet-switched data networks.

Advantages of packet-switched data network

1. can realize multi-party communication and greatly improve the line utilization rate;

2. High transmission rate and safe and reliable information transmission;

3. Charging has nothing to do with distance, and charging according to the amount of information and usage time is even better than remote communication;

4. Strong error detection and correction ability; Apply for an account and password (NUI), and you can roam the whole country.

Services provided by packet-switched data networks

Basic business:

1. Switched Virtual Circuit (SVC): It can communicate with different users at the same time, which is convenient and flexible.

2. Permanent Virtual Circuit (PVC): A fixed connection with one or more users can be established.

Optional business functions:

1. closed user group (CUG): communication is limited to specific users to avoid external interference.

2. Network User Identification (NUI): It provides strict security and can realize national roaming.

3. Broadcast service: one-way point-to-multipoint information transmission.

4. Reverse billing: paid by the called party.

5. Quick election: This kind of business is suitable for the bank's withdrawal business, but both parties must be users who can accept the quick election business.

6. Stop incoming/outgoing calls: users can't answer/make outgoing calls for a period of time, but they can make/receive incoming calls.

7. Call forwarding: When the user is busy or fails, the switch automatically forwards the user's call to the number reserved by the user.

8. Search Group (HG): When a user has multiple lines connected to the network, the load on each line is balanced to improve the connection rate of the customer as the called party.

New business functions:

1. Frame Relay: provides high-speed communication and realizes voice, data,

2. Integrated transmission of images; Information Card Authentication Service (POS): Data can be transmitted simultaneously on a telephone line without interference, which is 2-3 times faster than the traditional POS service;

3. Virtual private network;

4.SNA network environment;

5. Token ring LAN intelligent bridge function;

6. Asynchronous Polling Interface (APT).

Application scope of packet switched data network

Packet-switched data networks are suitable for the following objects:

Banking, insurance and securities; Customs; Taxation; Retail industry; Other companies, enterprises and institutions that need to realize computer networking;

Access location of packet-switched data network

1. Most cities above prefecture level and some towns and villages in China.

2. The international community includes Hongkong, Macau, Taiwan Province, Europe, the United States, Japan and some other countries and regions.