GPRS is the abbreviation of General Packet Radio Service, which breaks through the thinking mode that GSM network can only provide circuit switching, and realizes packet switching only by adding corresponding functional entities and partially transforming the existing base station system. The investment in this transformation is relatively small, but the user data rate obtained is considerable. GPRS(General Packet Radio Service) is a data transmission technology based on GSM, which can be said to be the continuation of GSM. GPRS is different from the way of continuous channel transmission in the past, and it is transmitted in the form of Packet, so the cost borne by users is calculated by the unit of data transmitted, rather than using the whole channel, which is cheaper in theory.

at present, the mobile phone formats mainly include GSM, CDMA and 3G. Since its advent, mobile phones have experienced the first generation of analog mobile phones (1G), the second generation of GSM, TDMA and other digital mobile phones (2G), the second generation of CDMA and the third generation of 3G.

Comparison among GSM, CDMA and 3G:

The GSM digital mobile communication system was designed by the standardization committee composed of major European telecom operators and manufacturers, and it was developed on the basis of the cellular system. Including GSM911MHz, GSM1811MHz and GSM1911MHz. GSM system has several important characteristics: good anti-theft copying ability, large network capacity, rich number resources, clear call, strong stability, sensitive information, few dead ends in call and low power consumption of mobile phones.

CDMA is the abbreviation of Code Division Multiple Access, which is a brand-new and mature wireless communication technology developed on spread spectrum communication technology, a branch of digital technology. It can meet the high demand of the market for the capacity and quality of mobile communication, and has the characteristics of high spectrum utilization rate, good voice quality, strong confidentiality, low dropped call rate, small electromagnetic radiation, large capacity and wide coverage, which can greatly reduce investment and operating costs.

MMS means multimedia short message service.

MMS is very similar to SMS and EMS in concept, which can be understood as the evolution from SMS to multimedia. But unlike SMS and EMS, MMS has almost no restrictions on the size or complexity of information content. MMS can not only transmit text messages, but also images, videos and audio. Therefore, the biggest change brought by MMS is that operators can develop more diversified mobile communication services. MMS can not only send and receive multimedia messages, but also send and receive emails containing attachments. From the user's point of view, multimedia applications will be the key to attract them to use.

JAVA, a network-oriented programming language, is used for programmers to create applications, which can be downloaded through the network and run safely on any computing platform. If you add the World Wide Web and corporate intranet system, you will have a standard network computing environment. As a distributed and object-oriented programming language, Java can allow any computer located anywhere to apply applications on the network.

if you look at Java from a business point of view, it is fashionable. Compared with many other programming languages with a history of 21 years, Java has absorbed all kinds of latest achievements in the field of computer science. On the other hand, because Java is still young, it lacks the support of rich programming tools such as Visual Basic or C++.

like C++, Java is an object-oriented language, which means that software can be compiled in the form of components, and in order to meet a certain task, software components can cooperate with each other. Running Java doesn't have to be done in a network environment. Like other traditional programming languages such as COBOL or Basic, Java can create independent applications. It's just that Java is better at developing applications on the Internet.

Java is suitable for the development and application of the Internet. One of the reasons is that it uses a virtual machine. A virtual machine is a software package used to interpret Java instructions, which allows Java to run on any machine, such as a virtual machine package running under Mac or UNIX. Virtual machine is not the Java language itself, it is an interpreter software written for a specific machine. Java's virtual machine strategy is equivalent to Esperanto, which is an artificial international language to make translation and communication between different languages easier.

to be called a general computer language, Java is the most suitable, which means that it can run on all computers (although Java virtual machine software needs to be written for various machines), it can provide soft parts as required, and it has inherent security mechanism.

The operating system written in Java, called JavaOS, is a language-based operating system, which seems to have no chance to occupy the PC market. But it provides clues for the future development of Microsoft Windows and MacOS. It may be applied to various instruments and equipment in the future, including TV remote control and temperature controller.

Web-based content providers are interested in Java technology because it adds interactivity and animation functions, which are the key factors to attract audiences. For software vendors, Java is hopeful that people can rent software, such as word processors or spreadsheet software, without buying software, which has changed the current business model.

Java has also made network computers a reality, and a $511 PC

without a hard disk will be able to replace the Wintel computer. All this shows the importance of Java, and its supporters regard it as the last and best hope against Microsoft and Gates, which is why some people show fanatical worship for Java.

EDGE is a network standard. If your mobile phone is GPRS-enabled, it will be automatically converted into the EDGE network management number 81 proxy server 11.1.1.172

LZ. I have been looking for these things for a long time, so please give them to me.