Talking about the construction of CDMA 1X core network

Absrtact: Unicom CDMA 1X Test Network is in Beijing, Shanghai, Guangzhou, Hangzhou, Chengdu, Nanchang, Hainan 7. It is based on 95A online equipment manufacturers distribution, and fully consider the future of the network upgrade of the various possibilities for the future construction of the preparation and accumulation of experience. This article mainly talks about its core network construction.

1 background, purpose and content of the test

The mature technology, foreign successful commercial and large-scale construction of China Mobile GPRS have led to the construction of CDMA 1X test network as soon as possible in order to remain invincible in the competition. The purpose of the construction test net is to test the coverage, switching and capacity of 1X system voice and data, and then test the data transmission performance and coverage under different moving speed, and finally verify the 1X system's back compatibility characteristic to 95A system.

Through the test, we can verify the feasibility of 95A equipment transition to 1X, at the same time provide business model for future 1X commercial network, accumulate engineering experience, reserve Technical force, show the future foreground and various applications of Unicom CDMA digital cellular communication network to the whole society.

CDMA 1X back-compatible with the existing CDMA 95A system, so now the online business can be implemented on the test network, the focus should be wireless data services, including:

(1) Wireless Internet service, such as: In CDMA 1X can be opened Internet access services, information type business, personal information management business, transaction business, entertainment business, industry application business.

(2) Mobile location business, such as: Public Security Service, location-based billing, tracking service, location-based call Routing service, location-based information service, etc.

(3) Mobile E-commerce business, such as: safe e-mail, secure mobile office, electronic banking, electronic securities, electronic lottery tickets, electronic ticketing and so on.

(4) Mobile multimedia services, such as: VOD and so on.

Construction scheme of 2 CDMA 1X core Network

At present, the air interface technology of CDMA network equipment operated by Unicom is 95A, and the corresponding core network is +IWF to realize low-speed data service by traditional circuit domain. Considering the possibility of most manufacturers, the core network structure of Unicom CDMA 1X test Network is referred to release 0. (Computer science)

2.1 Circuit domain Networking scheme

The construction of circuit domain is the first stage of the whole test net construction, there are two kinds of mixed network scheme and independent network scheme.

(1) Hybrid network (upgrade network) scheme

That is, CDMA 1X core network circuit domain MSC/VLR, HLR, AC and other hardware compared to 95A, the test network in each city selected one of the MSC/VLR, HLR and other network elements for the corresponding software upgrades, while the operation and maintenance center operation and maintenance software, billing center billing software upgrades.

The network elements involved in this scenario that need to be upgraded are as follows:

*MSC/VLR software upgrades Add functionality: Support IOS4.0 parameters, support IS-2000 1X High Speed Packet data Service (Service Option 33), support IS-2000 1X voice and 95A voice business switching, IS-2000 1X channel control capabilities, To the switch billing function software, operation maintenance software upgrades and so on.

*HLR Upgrade Main Features: User attribute management for IS-2000 1X high Speed Packet Data Services (Service Option 33).

* In addition Billing Center, O&m Center also need to increase the function of the data business.

The advantages of the scheme is to save investment, the disadvantage is that the need for 95A online equipment, software upgrades, once the failure, the current online 95A users have a greater impact.

(2) Independent network scheme

That is, the new MSC/VLR and HLR are used in the test network.

This program is in the city of new switches MSc, HLR and in the beginning, completely simulate Unicom's existing 95A network environment, in the first phase of the load support 95A base station, after fully verifying the 95A voice function, on the basis of 95A, the implementation of CDMA 1x function software package, Or in the original 95A network based on software upgrades to achieve the CDMA 1x function, and at the same time support 95A and CDMA 1x base Station. Its advantage is that the impact on the 95A network is small, but the disadvantage is due to the new network element equipment, increased the corresponding investment.

Since the CDMA 95A network construction is positioned to attract high-end users, boutique network and Unicom in the operation of the lack of experience, in order to minimize the impact on the 95A network users, and fully test the manufacturers of equipment from 95A network to upgrade the possibility of CDMA 1x and CDMA 1x function verification, It is more suitable to use the Independent network scheme in the circuit domain.

2.2 Construction scheme of packet data network

In release 0, simple IP and mobile IP correspond to different network architectures. Simple IP is the local pdsn assigned dynamic IP address, the business provider to obtain IP routing, users can be within the same PDSN jurisdiction to maintain their IP address, different PDSN do not have IP address mobility. Mobile IP is provided with static or dynamic IP address by IP network ha, which is fixed between different pdsn or different wireless networks during user data Service activation.

The basic network structure when moving IP (phase III).

Taking into account the actual support of the equipment of the manufacturers, the packet network can be divided into two steps: First, the use of simple IP to provide access services. When the function of simple IP has been stabilized, the test point can be selected to test the function of mobile IP.

(1) Network element setting of packet data network (simple IP)

In order to support the simple IP function of the network structure, in the test network core network part of the need to configure PDSN equipment, AAA server and other equipment.

1) The setting of PDSN equipment

Pdsn belongs to the data products, in order to maintain convenience, combined with the network situation, as far as possible with China Unicom 165 network of Provincial network routers located in the same site.

2) AAA Server Setup

AAA server is mainly used to realize the user authentication, certification, billing. At the beginning of the test network, considering the number of users, the number of cities to experiment is relatively small, location is more important, and in order to verify the interoperability between AAA in the test network compatibility, and the existing settlement system settings, for the future substantial expansion of experience, so the use of each city set 1 sets, Jurisdiction of the city's users of the authentication, billing and certification, at the same time, Beijing, Shanghai, Guangzhou AAA billing certification server to do the test network between the first Class AAA billing authentication server.

3) DNS settings for domain name servers

In order to realize the mutual correspondence between domain name and IP address, DNS of domain name server is required to accomplish the above work. The test network provides data users with Internet service and enterprise VPN service, and users can use the existing Internet and the DNS of the enterprise network when using these two kinds of business. So the test network can not build DNS.

For those who provide dedicated services to the provincial network of nodes (such as VOD server, etc.), you can consider the construction of the corresponding DNS.

4 Construction of Application server

Only by providing a variety of application services to attract users to use the data business, so that the data services to be better carried out. In the construction of 1X test network, in addition to providing traditional due to multiple visits can be considered in the Unicom's data network to provide some characteristics of the data services, such as WAP applications, VOD service to better conduct business.

(2) The construction scheme of IP bearer network of packet data network from the point of full utilization of resources, in the stage of test net, we can use Unicom uninet network as its IP bearer transmission network. AAA Server (Mobile IP phase of HA, FA) and other devices as Uninet network element, PDSN as uninet access devices, access to uninet network. User access, can be used as a common Internet users, but also as a VPN user access to the Enterprise network. However, it is necessary to enlarge the existing Uninet network equipment accordingly.

(3) Allocation of IP address

1 IP address assignment scheme for mobile terminals

A public address is an IP address that is applied to an Internet address assignment organization for legal use on the Internet, and a private IP address generally refers to an IP address used internally by an enterprise. Because private IP addresses are not addressable on the Internet, NAT (Network address translation) is required to access the Internet using private IP addresses.

In the existing IPV4 address space has been very tense, you can use the private IP address, and then NAT conversion, but some applications in the NAT can not be used, such as some special business needs of users in the future implementation of mobile IP features, you can consider the allocation of public IP address.

2 Core network equipment IP address allocation scheme

The interface of CDMA core network device is proposed to adopt private IP address, such as PCF, PDSN R-p interface, network management interface and so on. Use public IP addresses for interfaces that need to interact with the Internet, such as PDSN external Data network interfaces, AAA servers, and so on.

(4) Mobile IP test

On the basis of simple IP network, the corresponding software upgrade and new network element equipment needed for mobile IP function are realized. Strengthen the software function of all the PDSN in the test net, make it have FA function. All AAA servers in the test network also have software upgrades to support the billing of mobile IP services. The HA device should be added at the selected test point.

A wide area network connection between the new HA and its local pdsn/fa, AAA, WAP gateways is made between the test points and the LAN and offsite PDSN/FA.

3 concluding remarks

From above to the circuit domain, the group domain analysis, the author thinks that the Unicom CDMA 1X Test Network provides the different goal may carry on the test in stages, the stage divides as follows:

The first stage: complete simulation of Unicom 95A network environment, the construction of a test network of 95A circuit domain equipment, for 95A upgrade 1X preparation.

The second stage: Test cdma95a to 1X circuit domain Smooth upgrade ability, on the basis of 95A network stability, in the circuit domain network element device partial load support CDMA 1X software function, new CDMA 1X packet data network part equipment, test CDMA 1X support for voice features and simple IP case data features.

Phase III: On the basis of the first two stages, in the group domain equipment part of the increase of HA equipment, strengthen the PDSN function software to enable it to have the FA function, in the case of non commercial CDMA 1X mobile IP testing and the compatibility between the various equipment manufacturers, for the future commercial technical preparation.