Research on the evolution of CDMA network and the business model of Unicom

Previous years in the industry to talk about 3G mobile communications, compared to the hot situation, in recent years on the 3G mobile communication propaganda, discussion low-key and rational many. International, 3G license issuance is blocked, the application market prospects are not clear, coupled with the development of the telecommunications industry generally depressed, faced with these grim market realities, operators and manufacturers of the third generation of mobile communications to rethink the construction, technology development strategy has become pragmatic and realistic. After all, 3G communication is only to provide users with a higher data rate of the technology, it realizes data, voice, image of the initial combination of human beings to achieve "3W" global seamless communication, arbitrary high-speed communications business ideal still have a long way to go.

At present, in the development of communications industry is at a low ebb, the parties concerned are also actively preparing, saving strength for 3G large-scale commercial planning. The test and evaluation of the national 3G Expert Group continue to be intensively carried out, domestic and foreign equipment manufacturers to 3G research and development has been part of the product, more importantly, with the CDMA 1X and GPRS network into use, the frequent introduction of business, packet data services and users have been presses and nurtured, These all provide the condition for the large-scale application of 3G mobile communication network.

3G technology is mainly divided into cdma2000 and WCDMA two camps, this article focuses on the CDMA2000 series of technical standards, network deployment, business applications and China Unicom in the CDMA 1X online business. (Computer science)

I. The evolution of CDMA standards

Qualcomm first to the Military Code Division multiple Access communication technology into civilian mobile communications technology, since the establishment of IS-95 air standards, in order to continue to extend the compatibility requirements, TIA and 3GPP2 organizations have launched CDMA 1X, EV/DO, EV/DV technical format, To meet the growing demand for voice and packet data services.

CDMA 1X introduces new technologies such as anti-wizard frequency, coherent demodulation, forward fast power control, turbo code, diversity launch, long interleaving and auxiliary pilot, which greatly improves the system capacity and system performance on the basis of is-95a, and also supports the forward and backward peak data rate up to 153.6kbit/ s and 307.2kbit/s Data Services, business support capabilities have been significantly improved. 1999 3GPP2 successively published c.s.0001 (IS-2000) series of specifications, the physical layer, MAC layer, LAC layer, Layer 3 signaling, such as air interface protocol. IS-2000 's REL.A, rel.b two versions support 153.6KBIT/S and 307.2KBIT/S data Services respectively.

After the introduction of CDMA 1X, in order to provide higher data rate technology, Qualcomm Advanced HDR (High data Rate) technology, and as 3gpp2 HRPD (Gao Rate Packet Data) standard released the Air Interface c.s.0024 (IS8560) version in December 2000. Because HRPD is specialized in providing high-speed data services, "data only" technology, it is also known as "ev/do." Ev/do can provide forward to reach the 2.4mbit/s, reverse 153.6kbit/s high-speed data services, it does not support voice, also do not need MSc, HLR and other equipment to invest. The ev/do further improves the forward link, using the time division Multiplexing method, the forward realization of the full power launch, while in the frequency band, bandwidth, chip rate, Tubro code and other aspects of the original 1X technology, not only improve the data throughput, improve the packet area QoS, and fully consider the smooth upgrade problem, With 1X network maximum equipment sharing, protect the operator equipment investment.

Considering the need to provide a higher rate of data service to support real-time video business, 3GPP2 has finally determined the EV/DV technical standard on the basis of soliciting a variety of technical solutions. In the EV/DV Ph1 phase, the 1.25MHz bandwidth forward peak rate can reach 3.1mbit/s, the reverse rate is higher than 1mbit/s, and the HSDPA of WCDMA 5MHz bandwidth peak rate is in the same order of magnitude. At present, the EV/DV Air Interface Specification C.S.OOOX-C (IS-2000-C) and a Interface Specification A.s.001x-a (IOS4.3) have been released, and a c.s.000x-d version of air interface and IOS5.0 a interface specification is scheduled for release at the end of this year. EV/DV is the same carrier to achieve voice and data technology, can provide high-speed real-time data/voice communication services. EV/DV provides fast call setup, universal security algorithms, IP Multimedia and broadcast channels, End-to-end QoS guarantees, and signing rates.

Ii. The evolution of CDMA network structure

1. CDMA IS-95 Network structure

The traditional CDMA is-95a network structure includes base station (BS), Mobile Switching Center (MSC), Attribution Register (HLR), visiting location registers (VLR), also includes devices that support intelligent service business exchange points (SSP), Business Control points (SCP), Smart Peripherals (IP), In addition, network element nodes such as Message Center (MC), Short message entity (SME), interoperability function (IWF) are also included in the provision of circuit-type data services.

2. CDMA 1X Network Structure

is-95a Evolution to CDMA 1X Network, the circuit domain part of its core network is consistent with the IS-95, but in order to satisfy the packet data service, only the new PCF (Group control function), PDSN (Packet Data Service node), AAA (authentication, authorization and billing) and HA (attribution agent) and other grouped domain network elements are needed. To add A8, A9, A10, A11 interface processing between BSC-PCF and PCF-PDSN business and signaling messages. In addition, in order to support the data service, it is necessary to create new PDE and MPC positioning service and WAP Gateway Service platform equipment.

3. EV/DO Network Structure

The access network of EV/DO network is equivalent to the base station subsystem of 1X system BSS,PCF and the original 1X PCF basic function. The network mainly increases the SC/MM and the access authentication two functions. Wherein SC/MM is located in an. The new interface for 1X ev/do Phase 1 network structure is: A12, A13 interface, it is used for the communication between the wireless access authentication and the switch between the An. The Japanese KDDI support ev/do Phase 2 's network architecture adds A12, A13, A14, A15, and AX interfaces.

4. EV/DV Network Structure

The EV-DV network structure is the same as the 1X, completely rear-compatible 1X and IS-95.

From IS-95 to CDMA 1X, and then upgrades to Ev/do and EV/DV, CDMA2000 standard evolution is very smooth. When upgrading to CDMA 1X network, operators only need to increase the carrier frequency RF components and upgrade software, while building a packet domain network. Transition to EV/DV, the network structure is also basically the same as the 1X, even if the special provision of data services ev/do, only need to increase the BTS/BSC, increase an-aaa, group domain, circuit domain equipment need not change. This shows that the CDMA network after the compatibility of the design concept of the operator equipment investment has been the greatest degree of protection.

Third, CDMA2000 network global application situation

As of 2003 1, the global CDMA users reached 150 million, of which 44 million were cdma2000 users. Mainly distributed in the Asia-Pacific region of China, Japan, Korea and the Americas, Canada, Brazil and other countries, so the CDMA deployment area is our country and in addition to Europe's major economic and trade countries.

October 2000, South Korea launched the world's first cdma2000 1X network, and then on January 28, 2002, the first launch of the commercial cdma2000 ev/do services. In South Korea operator led by the Japanese KDDI also in April 2002 to provide CDMA 1X services, and this spring opened CDMA2000 ev/do Experimental network. To date, a total of 47 1X network investment in commercial and 21 network is about to deploy. And the Ev/do network also opened 4, in addition, there are 3 experimental networks.

CDMA network mainly provides WAP browsing, positioning business, email, java Application download, brew program download, video business, electronic transaction business. With the rapid increase of people's demand for mobile data service, the penetration rate of mobile data service is increasing. CDMA Data Services account for the increasing proportion of business income, and also make great contributions to the improvement of ARPU value.

In Japan KDDI and South Korea Skt, KTF, LGT and other operators cdma2000 a large number of commercial, while the European operators have to reduce WCDMA commercial expectations, WCDMA and CDMA 2000 in the initial 3G commercialization of competition, in the network deployment, the number of users or support services, CDMA 2000 are slightly better than WCDMA. In Japan, for example, in October 2001, Nttdocomo launched a 3G commercial service called "Foma", with a slow growth in the number of users and only 140,000 users in October 2002. In contrast, KDDI launched the CDMA 2000 commercial network in March 2002, and increased its 3G service users to 2.5 million by September 2002.

Iv. China Unicom Business development model

China Unicom after three-period network construction, cdma1x capacity will be increased from 35 million to 50 million, while the number of CDMA users is also higher than 10 million. On the IS-95 network, China Unicom has provided complementary services, including short message and other low-speed circuit-type data services, as well as VPN, prepaid and other intelligent services. On this basis, March 2003 China Unicom also launched a comprehensive CDMA 1X network support business, mainly WAP browsing, multimedia mail, Brew/java software downloads, positioning services, short message transceiver, wireless internet card business. Unicom new Time and space launched a unified CDMA wireless Data Services "Unicom Unlimited (U-max)" brand, with 1X network unparalleled high-speed data transmission advantages to launch the "Color E", "Interactive World", "Magic Treasure", "Palm broadband", "Positioning Star" and "Unicom in the letter" and other new services, To provide users with communication and entertainment experience, thus greatly enriching the CDMA network business.

"China Unicom Unlimited (U-max)" brand under the respective provision of the following services: "Color E" so that the mobile phone in addition to sending text messages, but also to send pictures, music, video, animation and other multimedia information, and can communicate with e-mail, support 5000 Chinese characters within the long text and multimedia accessories to transfer; "Palm Broadband The use of mobile phone to achieve anytime, anywhere high-speed wireless internet access; interactive Horizon "can use mobile phone for" a key to the Internet, "Magic treasure" can download a variety of applications from the Internet, to achieve mobile phone upgrades, "positioning Star" to provide location inquiries, traffic navigation, find friends and other location services, rely on mobile phone can be accurate positioning, The accuracy can reach 5 to 50 meters.

From the CDMA technology standards proposed to the network deployment, by the International business applications and China Unicom's online services visible, CDMA series technology has a smooth transition, back to the compatible network design, stable and mature standards, a wealth of business to provide capacity, as well as Low-cost upgrade investment and other characteristics, These features will attract more and more operators to consider using CDMA to deploy 3G mobile communications networks.