3G is the third generation of mobile communication systems

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Mavzu: 3G is the third generation of mobile communication systems

Plan:

1. 3G is the third generation of standards

2. 3,5G generation standards

3. 3,75G generation standards

4. 3G is the third generation of cellular communication systems

5. Development history of 3G systems

6. Construction principles of 3G systems

7. 3G standards

Key words: IMT-2000, TDD, Wideband-CDMA, IMT-DC, UMTS, FOMA, GSM/GPRS/EDGE, High Speed ​​Packet Access, all-IP–architecture 3.1. 3G - third generation standards Thus, the main disadvantage of the second generation mobile communication systems at the end of the last century is their low 9,6-14,4 kbit/sec. data transmission at high speed. Therefore, within the framework of IMT-2000, efforts were made to achieve data flow speeds of up to 3Mbit/sec for subscribers with low mobility and up to 2kbit/sec for mobile subscribers in 384G networks. It is known that there are two global cooperative associations that form the third generation standards known as 3GRR and 3GRR-2. 3GRR participants achieved coordination of specifications for W-CDMA (see Wideband-CDMA) technologies using frequency (FDD) and time (TDD) duplexing and presented the IMT-DC and IMT-TC projects, respectively, to HTI. UTRA FDD and UTRA TDD options were set as the basis for the organization of the radio interface based on the European proposals - UTRA (see UMTS Terrestrial Radio Access - radio interface for terrestrial connection to the UMTS system). Members of the 3GPP-2 consortium proposed evolutionary paths for the development of D-AMPS technology to UWC-136 technology and cdmaOne technology to CDMA-2000 technology. These proposals were submitted to HTI as projects IMT-SC and IMT-MC, respectively (see Table 3.1). Thus, despite attempts to unify standards at the 2000G level within the framework of the IMT-3 Program, two families of incompatible standards based on W-CDMA (UMTS, FOMA) and CDMA-2000 technologies have emerged in the world (see Table 3.2). The third generation mobile communication systems will be detailed in the following paragraphs, so here we will limit ourselves only to their development process.

The introduction of UMTS networks was a fundamental new stage in the development of mobile communication and allowed to reach a maximum speed of 2,048 Mbit/s in mobile networks. The main difference between UMTS systems and GSM/GPRS/EDGE systems is the use of broadband signals (KPS) with a bandwidth of 5 MHz. Another advantage of the UMTS technology is the high immunity of the signal and its stability to the effects of multi-radiation. In addition, the use of KPS allows the use of code channel division method (CDMA). An intermediate step in the development of the sdmaOne (IS-95) standard was the IS-95b specification. It can combine up to 8 logical channels and 14,4*8=115,2kbit/sec. allowed to reach the theoretical speed (real speed was 64kbit/sec.). The next step was the CDMA-2000 project, which ultimately had to meet the requirements set by IMT-2000 for 3G networks. Three stages of development of CDMA-2000 standards were envisaged: 1X (at 2,75G level), 3X and SDMA-2000DS (see Direct Sequence – ―right sequence‖). Since the latter phase is technically similar to W-CDMA, work on it has been discontinued. The CDMA-2000 family of standards has been transitioning from 3G-level networks to Pre-4G-level networks. But nowadays 3,5G; 3,75G; When it comes to 3,9G generations, in our area more 3GRR (ie UMTS – HSPA – HSPA+ and LTE) technologies development stages are meant. (Figure 3.1).

3,5G generation standards Multi-position quadrature-amplitude modulations, i.e. 16-QAM, 64 HSPA (High Speed ​​Packet Access) technology using QAM methods was developed. In order to reduce the response delay time in this technology, the main attention was paid to the modernization of the MAS (media access control) - control protocol of connection to the environment. HSPA technology was introduced as a Level 3 specification of the 6GPP project standards (see 3GPP Release 6) and is usually referred to as belonging to the 3,5G generation. In turn, the HSPA standard consists of two constituent technologies - HSDPA and HSUPA. HSDPA (see High-Speed ​​Downlink Packet Access - high-speed packet transmission of data in the "down" direction) is a mobile communication technology evaluated by experts as one of the intermediate stages in the transition to the fourth generation technologies. The maximum theoretical speed of data transfer in HSDPA technology can reach up to 14,4 Mbit/sec, and the practical speed achieved in existing networks is 3 Mbit/sec. Like HSDPA technology, HSUPA (see High-Speed ​​Uplink Packet Access — technology for high-speed data packet transmission in the "up" direction) is a mobile communication technology that allows speeding up data transmission from the user's W-CDMA AU to the BS due to improved modulation methods. Theoretically, the HSUPA technology is designed to transmit ―up‖ data at a maximum speed of 5,76 Mbit/s, which allows to run third-generation applications (for example, video conferencing) that require a large flow of data from the AU to the BS.