Analysis of overall network design scheme of 3G Test core network

With the development of mobile communication in China, the construction of the third generation mobile communication network has become the focus of major telecom operators.

The third generation mobile communication technology test network of the Ministry of Information industry is led by the Ministry of Information industry to participate in the formation of the major telecommunications operators, the test network in the 2GHz band, respectively, WCDMA R99, TD-SCDMA, CDMA2000 1X Three kinds of technology construction, of which, CDMA2000 1X using simple IP mode TD-SCDMA adopts LCR system; This network construction is only used in 3G technology test, not with the current network interconnection, regardless of the intelligent network, regardless of the actual volume of business. The experiment was conducted in Beijing, Shanghai and Guangzhou, and the WCDMA test network was set up by 17 systems of 15 manufacturers, and the CDMA2000 test network was established by 9 sets of 9 manufacturers. In Beijing, Shanghai by 3 manufacturers, 3 sets of systems to establish a TD-SCDMA test Network. A test system for each technique consists of a core network, a wireless network (5-20 base stations) and a corresponding supporting equipment. The following focuses on the 3G technology test core network of the overall design considerations.

1. Circuit field

The test network in three cities respectively set up WCDMA tmsc and cdma2000 of Tmsc, used to connect the local circuit information separately and as the Gateway Bureau of Interconnection. When the long-distance circuit is in charge of transferring long-distance traffic, TD-SCDMA only serves as the tmsc of local WCDMA respectively. The circuit domain includes the traffic network and signaling network, and its networking scheme is considered as follows:

1.1 Traffic road network

(1) 3G system with technology

The CS Domain core network of three cities in this test network uses two-level network structure, in order to save the transmission resources without considering the volume of traffic, the CS domain core network between the local test systems uses a single star network structure, (in a computer room, multiple vendors of the MSC can be directly linked to each other). (Computer science)

Due to the small volume of business, the test network only in each city set a bridging node, and the test system Gmsc, select a manufacturer of MSC at the same time as a tmsc/gmsc. The network structure of the TMSC is adopted in the long-distance layer of the experiment net. The information between CS domain of each city test system is transferred through the connecting node of the main call city and the connecting node of the city called.

What needs to be specially explained is: in the actual commercial network, in the network structure aspect, should according to the actual business volume forecast, the network security, the transmission resources and so on many kinds of factors, determines is uses the NET network structure, the net and the star-like mixed structure or the double star network structure. In connection with the node, in order to consider network security, should be not less than 2 pairs of settings. At the same time should be based on the actual carrying capacity of the traffic, consider whether to concurrently as tmsc/gmsc.

(2) Interoperability with 2G systems

In this 3G test, the 3G network is not connected with the existing commercial 2G system. Interoperability with the 2G system is achieved by using the 2G GSM of the Mtnet laboratory. A direct relay of WCDMA GMSC/TMSC and 2G MSC system should be set up in Beijing.

(3) interworking between the road network and the PSTN

In three cities, the PSTN is set up separately and is not connected with the present network, and is shared by WCDMA, CDMA2000 and TD-SCDMA. In order to facilitate the interoperability of the test, the new independent PSTN in principle with the gmsc/tmsc with the computer room settings, by the city of different technology gmsc/tmsc respectively with the city independent PSTN set up direct relay.

(4) Interoperability between 3G systems of different technologies

In order to realize three kinds of technology network interworking, each city different technology 3G test Net TMSC/GMSC serves as the gateway Bureau of Interconnection, between the two sets direct relay.

1.2 Signaling Network

(1) 3G system with technology

Due to the small volume of business, this test network adopts SP/STP comprehensive setting method, namely: the Tmsc/gmsc network element and Stp/sp node of three cities in the test net, the test net sets up an STP point in each city to dredge the signaling between each network element sp of the local arbitrary two sets of systems. The various STP networks are connected, and the SP signaling between different cities is transferred through the main called side STP and the called side STP. The SCCP message between each signaling point SP uses GT addressing mode, the translation point is the STP of the originator, and only one GT translation is done.

Need to explain: in a certain scale of the actual commercial network, TMSC network element and STP should generally consider separate settings. STP should be set up in pairs, load-sharing, mutual standby. You should also decide whether to set up a direct signalling link based on the size of the message amount between SP points.

(2) Interoperability with 2G system and PSTN

Beijing Mtnet Laboratory 2G GW as SP point access to Beijing WCDMA network Stp/sp signaling point.

Each city independent PSTN gateway/End Bureau serves as the SP point respectively to connect the city different technology 3G network the STP/SP signaling point.

(3) Interoperability with other 3G systems

The 3G network tmsc/gmsc of different technologies in each city are directly connected as SP points.

(4) Interoperability with the SMS system

In order to support the short message business, convenient operation around, reduce the signaling circuitous, save long-distance signaling resources, the city in principle using independent short Message center. The short message centers of different technologies in each city are only used as the SP point to set up a direct signalling link with the stp/sp of the city and the other SP points through STP transfer.

The 64K/S signaling link is used between SP Point and SP Point, SP Point and STP point in the test network, which is carried by E1 circuit.

2. Group Fields

The test network grouping domain uses two level network structure, namely: by each city IP local network and IP national backbone network composition.

To conserve network resources, this test network considers WCDMA, CDMA2000, TD-SCDMA group Domain common unified IP backbone platform, namely: Only in Beijing, Shanghai, Guangzhou each built 1 for three kinds of technology Common Core routers, the establishment of national IP dedicated backbone network, and provide IP backbone transmission.

At the local network level, when the same city operators have more than two manufacturers of equipment, you need to set up a public node router, each node router and the local core router star-type connection. All the packet-domain systems of each 3G test network are connected to the unified IP backbone platform through the local core routers and provide the interworking and roaming between the systems through the core routers.

The test network in each city to build a public DNS, and the core routers directly linked to the city's cluster network in the domain name resolution.

It should be explained that in the actual commercial network, it is generally recommended that the national root DNS and provincial level DNS level two settings. In addition, the backbone of the core routers and DNS should be set up to each other for backup, load sharing. A dual-star network structure is formed between the core layer router and the Access layer router at the local network level.

The test network in each city according to the technology set up business platform, in principle, the business platform set in the core router in the computer room, its router by the core router concurrently. In this way, the 3G test system can simplify the network structure by simply accessing the local business platform by the core router.

In order to facilitate the deployment of the transfer network resources, the CE1 interface is adopted between the core routers and the other node routers, and the FE interface is adopted between the core router and the Ethernet switch.

3.3G Business Platform

In order to test the business support capability of 3G systems and terminals, a business application platform is set up in three cities according to WCDMA and CDMA2000 technology.

This test WCDMA service platform system includes: WAP Gateway, LCS: Positioning service Platform, MMS: Through WAP-hosted MMS Center, Java Platform, Short message service platform, streaming media platform: for some support stream media terminal can carry out business ability test.

The test CDMA business platform includes: Set WAP gateway, CDMA positioning platform, MMS: WAP hosting, WAP: Set WAP gateway, CDMA positioning platform, MMS: through WAP hosting; Java platform, Videophone, Streaming media: For some terminals that support streaming media, they can test the business capability,

BREW (optional), SMS business platform.

As can be seen from the above network connections, business platform can be divided into the need for signaling network support and only in the IP network hosting two types of business, for the need for signaling network support business, such as SMS business, positioning business, because the signaling network to support the different protocols and the location of the implementation of different technologies, the business platform needs to be set separately.

For the service that only carries on the IP network, as long as sharing the same IP platform, the business platform can realize share. The test network TD-SCDMA, in addition to the wireless network to address the different positioning of the implementation of the need to build a positioning business platform, other businesses can share the WCDMA business platform.

4. Synchronous mode

In principle, the 3G Network Technology test does not establish an independent digital synchronization datum, but uses the synchronization datum of the existing digital synchronization network to realize the synchronization of the same technology test network.

The 3G test network is attended by six communication operators to provide room and transmission environment. They have their own clock system, and the input datum of bits clock is taken from GPs. In order to facilitate the implementation of the synchronized mode, the Tmsc and MSc in this test network are extracted from bits of the digital synchronous network of the machine building two synchronous clock source.

Need to explain: in the actual commercial network, in order to improve the accuracy of the whole network synchronization, the network elements of the whole network should try to use the same clock source of the benchmark clock signal, the network elements in accordance with the level of master-slave synchronous mode.

This 3G test WCDMA wireless network synchronous operation mode, CDMA2000 wireless network synchronization using GPS system synchronous working mode.

5, transmission network

The design of this test network is divided into two stages according to the test requirements:

The first stage of each city, different technology 3G system independent Network. The second phase of the same city the same technology of different systems, 3G Network and 2G Network, 3G Network and PSTN, different 3G technology interconnection between the connection. If you have the conditions, you can also connect with each other across the city interconnection.

The 3G test network construction mainly utilizes the existing SDH transmission network of various operators, considering the small volume of the test network, the E1 relay transmission is adopted uniformly. The voice and signaling information is transmitted directly through the SDH transmission system, and the IP packet information is transmitted by IP over SDH. This kind of way only need each operator to present the network transmission resources to carry on the unified dispatch, the implementation is convenient, the comparison economy.

According to the above network scheme, the third generation mobile communication technology test network of the Ministry of Information industry has been completed in Beijing, Shanghai and Guangzhou, and the current operators ' relay circuit allocation and vendor system's bureau data configuration and the joint adjustment work have all been completed and entered the testing stage of the whole network performance.

The completion of the 3G test network marks an important step in the research and commercialization of the third generation mobile communication field, the test network will test the maturity of each 3G technology system and business platform, and provide technical basis for the development of 3G mobile communication policy by the Ministry of Information Industry.

At the same time for 3G commercial when the interconnection of different technologies, the interconnection of different operators to accumulate a lot of valuable experience.