3G and 2G network convergence networking strategy (1)

I. Several networking strategies involved in network convergence

Although 3G has been under construction in foreign countries, and some of them are in commercial use and quasi-commercial use, the development of 3G in China and abroad is quite different. China's 3G development will be a long-term, gradual, and constantly improved process.

Traditional GSM network operators have a wide coverage of GSM/GPRS networks and a large user base, which is both an advantage and a limitation for the construction of 3G. Traditional GSM carriers must maintain their network coverage and user advantages, and minimize the adverse effects caused by the introduction of 3G, its network planning and construction model must be different from that of the emerging 3G mobile operators. The well-covered GSM network can be a huge advantage in the Construction of 3G networks, but at the same time in dealing with and solving the problem of effective networking in the 3G/2G network convergence, operators will also pay huge "opportunity costs ".

In the planning and construction of 3G networks, the following aspects are particularly prominent and important under the principle of "flexible economic network construction:

(1) Wireless Access Network: Roaming and switching between 2G/3G networks, sharing of infrastructure (site, indoor distribution system, data center, and antenna feed system.

(2) core network: problems such as the signaling network, bearer network, and BOSS System in the GSM network, and "number portability" between 2G and 3G networks;

(3) Business Network: intelligent network, business platform, and business management platform.

II. Specific Considerations for networking strategies

1. Wireless Access Network

(1) Roaming Problems

3GPP has formulated detailed specifications for system devices and terminals for roaming between 2G/3G networks and re-election of cells, and requires the original BSS to be upgraded, to support broadcast of 3G adjacent cells, inter-system switching, and other features. In addition, the MSC device needs to be upgraded to support inter-system switching.

In the case of dual coverage of 2G/3G, we prefer 3G users to first access 3G networks and keep them in 3G networks. In this way, on the one hand, we can provide users with better services, and on the other hand, we can share the load of 2G networks. When a 3G user leaves the 3G coverage area, the 3G to 2G network is re-elected. Once the user re-enters the 3G coverage area, the 2G to 3G network is re-elected.

It is important that, at this time, 2g bsc must be upgraded; otherwise, 2g msc cannot be automatically roaming back to 3G; for roaming, 2g msc can not be upgraded, 3g msc does not require any adaptation.

(2) failover

Due to the wide coverage of the GSM network, during the initial phase of 3G network construction and operation, for the call connection status of the voice service, the switching function of the dual-mode terminal from the 3G system to the GSM system is provided, it is more important than switching from a GSM system to a 3G system.

Currently, switching between 2G, 2G, 2G, 2G, and 3G still has many problems. 3GPP only sets the switching between 3G/2G in R99. Therefore, the original 2G network can be upgraded to R99 to support inter-system switching, and the original network can be upgraded, it is a huge risk for mobile operators. To solve the above problems, 3g msc is compatible with 2g msc, and 2g msc is not upgraded. Based on the current 3G network experience of ZTE, in addition to protocol-based adaptation of 3g msc, due to the presence of RNC, R99/R98 BSC under 3g msc in a specific network, for different situations such as R99/R98 BSC mounting under 2g msc (V3 and V2), more special requirements must be put forward for 3g msc.

(3) Infrastructure Sharing

◆ Co-site

In the construction of 3G wireless networks, it is not only feasible but also necessary to work with 2g sites. 3G site selection should take into account factors such as power supply, transmission (high-speed data services are particularly prominent), IDC space, and rationality of the original 2G site. All 3G site selection should be based on "2G co-site". Pay attention to possible problems in "using 2G site, 2G data center conditions, transmission, power supply restrictions, uneven coverage, etc.

◆ Shared Indoor Distribution System

In the initial phase of 3G network construction, we need to consider introducing a dedicated 3G Indoor Distribution System for some indoor hotspot areas. If there is a 2G indoor distribution system, priority should be given to the sharing of indoor distribution systems between 2G/3G. For the 3G Indoor Distribution System, sharing with GSM is a simple, effective, economic, and fast construction solution. 3G and GSM co-Indoor Distribution System, the original system changes are very small, mainly including two aspects of work: replacing the indoor narrowband antenna as a broadband antenna, it can serve both 3G and 2G systems at the same time. At the base station Device Access end, a dual-duplex bonding mechanism is added to ensure inter-system isolation requirements.

◆ Total data centers

The IDC is very important. The roof of the IDC room is complex. the bearing capacity of the civil building design may not meet the requirements of the 3g idc. The base station must be built flexibly. When space and load-bearing conditions are met, fully utilize 2G data centers and use RRU and micro-cells for coverage to save data center resources. Using RRU can greatly reduce the requirements of base station construction for data centers.

◆ Total antenna feed system

The resources shared by 3G and 2G systems can be achieved through the sharing of Poles, towers and other infrastructure. By using a specific multi-frequency combination, multiple systems share the indoor distribution system.

In China's future 3G construction, in addition to the above issues, there may also be problems of network cooperation between new mobile communication operators and old mobile communication operators. Especially in the early stages of 3G development, in order to meet the needs of the whole network coverage, the relationship between 3G and 2G networks must be well handled. Pay attention to the cooperation between the 3G network of the new operator and the 2G network switching and roaming of the old mobile operator, so that users do not feel that they are using different mobile networks of two different carriers.