Mobile wireless connection (GSM/GPRS)

The wireless connection is comprehensive, but the settings are confusing.

 

1. China Mobile wireless connection
1) GSM (CSD) -- GPRS (edge) -- 3G (HSDPA)
GSM (Global
System for Mobile Communications. GSM is the second generation wireless communication network standard, commonly known as 2G (2nd
Generation) network is also the first generation of digital signal communication network standards. The first generation of 1g (1st generation) is analog communication and has been eliminated.

 
CSD (circuit switch
Circuit (Cyclic) exchange data technology. CSD is the first dial-up Internet access method on GSM. It uses analog data transmission. The access number is 17266 (for example, mobile Dream network ). CSD
The email fee is 0.15 RMB/minute (30 RMB within 500 minutes for monthly use, charged by minute if the fee is exceeded ). When the CSD method occupies a channel, you cannot call the Internet. The CSD theoretical speed is 9.6 kbps, and the actual download speed is similar to this. Tom and mobile work together for 17201 business also through CSD, with the service number being 17201.

 
GPRS (General Packet radios
Service. The so-called 2G 5G technology is a product for the transition from 2g to 3G, and is an upgrade to GSM. GPRS is still based on the GSM protocol, which does not occupy the channel,
The maximum theoretical rate is 171.2 kbps. Currently, it is implemented at 53 kbps. The actual rate is generally about 40 kbps. Because data is transmitted in groups, data can be transmitted quickly and
Supports Wireless VPN. Billing is based on traffic. The fee is 0.01 yuan/kb (may vary across regions), and there is a corresponding package. Fees outside the GPRS package are amazing. For 1 cent/kb, 1 m is 10 yuan. How can a movie be compressed? Dozens of M is always there, that is, several hundred yuan. The distinction between cmwap and cmnet is shown below.

Edge (Enhanced
Data Rate for GSM
Evolution), often translated as enhanced data rate GSM Evolution technology. It is a GPRS upgrade. Edge does not change the structure of the GSM or GPRS network or introduce new network units,
To upgrade the BTS (sending and receiving base stations), the operator only needs to invest a small amount of resources, but can reach a rate of kbps, with a peak value of 2 Mbps. This allows you to provide video power to users three generations ago.
Conference and high-speed Email transmission and other wireless multimedia services, so it is called 2.75g or quasi 3G. The current fee seems to be a monthly subscription, and the service needs to be activated from mobile devices like GPRS. If it is not activated, it is still
GPRS speed.
3G (3rd
Generation), 3G is a general name, because it has not been activated in China, so it can only be called 3G. Its technical standards mainly include three types of WCDMA, CDMA, and TD-
. It is mainly supported by European manufacturers, including Ericsson, Alcatel, Nokia, and Lucent. Because WCDMA can be based on existing GSM networks, it has inherent technical advantages. CDMA 2000
Led by North American companies, from CDMA
1X network upgraded. TD-SCDMA is a 3G standard developed by China mainland (mainly Datang Telecom. We can see that Kaiser must support WCDMA. If you move
TD-SCDMA, Kaiser certainly cannot use 3G.

HSDPA (high speed download Packet Access) is often used for high-speed downlink access, because it optimizes the download rate and upgrades WCDMA. The Chinese Mainland cannot use it now.

2) WAP/cmwap/cmnet
 

WAP is a communication protocol. For example, if you want to send a letter (WAP), you can send it through the post office in multiple ways, such as express delivery (GPRS), Ping mail (CSD), or express delivery.
(WCDMA ). Of course, you can also send packages (such as e-mail. WAP first passed CSD, that is, dial-up. Later, WAP can also use GPRS or edge
And so on. Why do some machine friends say: I have paid for GPRS for a month? Why is there a WAP fee? That is, your wap goes through the CSD line, so you have to pay for it on time.

Why is there a distinction between cmwap (China Mobile WAP) and cmnet (China Mobile net? This is the ghost of China Mobile. Just like Ge You advertises shenzhouxing: I can see it, and the next time I will advertise it to global users: I can also see it. It is a move of things. It is intended to be divided into two sides, so as to fool everyone and profit from it. China Mobile GPRS network has two different access point names (Access Point name-access point ). Cmwap only provides WAP proxy and HTTP proxy.
The access scope is limited. During access, only IP addresses (10, *) in the GPRS network can be accessed. While cmnet provides the NAT service, the mobile phone that uses this service can directly access
Internet. When using cmwap, you can only use HTTP Proxy protocol (port 80 and port 8080) and WAP Gateway Protocol (Port 9201 ). You want to use POP3
Email? Or another port to play a game? Unless the program provides an HTTP proxy method (for example, mobile QQ has an HTTP Protocol. This is also what many machine friends say: the software on the mobile phone cannot be connected to the network? They are using the mobile Dream network (cmwap) access. Cmnet has no restrictions.

 

Then you will think, I will use cmnet. The charges are different. Do I have a monthly GPRS package? Why is there a difference? There are a bunch of monthly cards worth 20 RMB on the Internet.
A lot of things are useless, and the speed is slow. Some netizens also asked: Where is the cost of my GPRS subscription? Cmnet does not support monthly subscription, and only supports traffic (Plan ). Cmnet,
The monthly cost of the cmwap package is now a GPRS package. Some low-cost packages only support cmwap. If you use any software that uses cmnet, you will start charging by traffic instead of monthly subscription.
Only large packages are not limited to cmnet and cmwap, but there will always be traffic restrictions. For details, you need to consult the carrier. Mobile phones are customized in this way. It is your business to use software.

 

With the development of commercial competition and technology, cmwap and cmnet will disappear, and there is no such difference in foreign countries. By the way, let's see how China Unicom works. China Unicom's GSM network only has one way to access the WAP website
-- CSD (charged by minute); China Unicom's CDMA network only has one way to access WAP websites-CDMA (charged by traffic). China Unicom's management is called "interactive vision ".