MSTP Network: Constructing 3G transmission network with MSTP

Point of view 1:

In the construction of 3G mobile transmission network, a simple idea is to build a set of independent ATM network for UTRAN, but ATM switching equipment is more expensive, and as a basic network, practice proves that it is not the best solution for other business. In addition, ATM has the problem of automatic configuration and recovery time of the whole network connection in the use of fiber network, and it can't meet the requirement of service quality of telecom class.

Point of view 2:

With the increasing demand for data access, the 3G mobile communication system, which provides high-speed wireless data access, will be implemented. Therefore, it is necessary to fully consider the transmission demand of 3G system when constructing the transmission network.

Based on pure IP network is the direction of telecom development, IP with its simple and efficient features, in the telecommunications industry has been more and more attention. ATM is not the best 3G mobile transmission network in the construction, a simple idea is to build a separate ATM network for Utran, but ATM switching equipment is more expensive, and as a basic network, practice proved that it is not the best solution for other businesses. In addition, ATM has the problem of automatic configuration and recovery time of the whole network connection in the use of fiber network, and it can't meet the requirement of service quality of telecom class. In addition, because the IUB can adopt IMA E1 or ATM STM-1, the choice of different interfaces will not be identical to the requirements of mobile transmission network, so that the mobile transmission network is facing more complicated situation. (Computer science)

The physical interface that IUB can take is as follows:

(1) The IMA E1 interface is used in all the IMA E1 RNC side to connect with the Node-b ima E1. This method provides a large number of IMA E1 interfaces in the central RNC, and due to the limitation of the IMA mechanism, it is generally necessary to reserve a large number of E1 ports for node-b expansion, and the cost of the RNC is very high. Although the transmission system only needs to provide a simple E1 circuit transmission, but because the bandwidth between multiple node-b can not be shared, transmission bandwidth requirements are very large.

(2) using ATM STM-1 RNC and NODE-B directly to provide ATM based STM-1 interface instead of the multiple external IMA E1 interface. If using ATM STM-1 transmission, need a lot of bandwidth, the pressure on the transport network is too large. If the node-b directly for business statistics multiplexing, all node-b transport nodes to provide ATM STM-1 interface, and provide ATM processing, if the transmission network to carry other services, the line bandwidth requirements above 622M, investment costs. In addition, as the original GSM/GPRS base station transmission equipment generally only provide E1 interface, need all to upgrade and transform, not conducive to the protection of the original investment.

(3) ATM STM-1 and IMA E1 mix RNC provide ATM STM-1 interface and NODE-B provide IMA E1 interface, the RNC only provides a small number of interfaces, node-b only need to provide the IMA E1 interface, make the network concise and practical.

This method is confronted with the need for ATM signal processing between the RNC and the node-b to realize the conversion between the IMA E1 and the ATM STM-1. One method is to process on the RNC side, providing an ATM switch in front of the RNC, the IMA E1 ends on the ATM switch, and provides the STM-1 signal into the RNC. This approach reduces the cost of the RNC's investment and requires only E1 transmission at the transport level, but it requires an independent ATM device, which enables TDM transport and ATM processing layers between the RNC and the Node-b, providing an independent ATM network management system, and a large number of e1/between ATM devices and transmission devices. STM-1 connection, and cannot solve the statistical multiplexing problem of transmission bandwidth. In addition, because of the use of IMA E1, and the IMA E1 require multiple E1 interfaces to be continuous on the ATM switch, a large number of E1 ports need to be reserved on the ATM switch for capacity expansion. The high cost of ATM switches, coupled with a large number of E1 connections and reserved interfaces, makes the entire scheme very expensive and difficult to implement.

MSTP is the most suitable

MSTP provides a network platform based on SDH, providing a wide range of business interfaces and processing capabilities, providing flexible support for ATM, IP and TDM services, and delivering efficient transmission solutions for 3G operators. In view of the business features of the metropolitan Area Network, UT has developed a new generation of netring series of multi-service optical transmission products based on SDH, covering all products from STM-1, STM-4, STM-16 to STM-64.

Netring has a very good performance-price ratio, which can provide a complete solution for the three levels of metropolitan transport network construction (i.e. core layer, convergence layer and access layer). For 3G business needs, the Netring series provides a complete solution. Core network (CN) using large capacity 10G MSTP platform NetRing10000 composed of core ring, in the Utran using NetRing2500 composed of 2.5G convergence layer, NetRing600 composed of 155M access layer. In the early stage of mobile transmission construction, due to the low number of base stations, each base station requires a small transmission bandwidth, often using a layer of network, because of the growth of data metropolitan area network bandwidth demand and 3G network implementation, network layering becomes an inevitable trend. The convergence layer is introduced, and the business in a certain area can be brought together. After the introduction of the convergence layer, the structure of the access layer will be changed, the original demand for each base station less bandwidth, a 155M loop can cover multiple base stations. Because the data metropolitan area Network and the 3G greatly increased the transmission bandwidth demand, the access layer should gradually reduce the number of 155M ring coverage nodes (through the split loop implementation) or upgrade to 622M.

Because the interface of IMA E1 is adopted in the access layer, the Access layer network simply transmits the Node-b E1 to the aggregation Layer node and provides ATM processing at the node of the convergence layer. NETRING2500 provides a card with ATM exchange capability, and uploads the IMA E1 circuit to the access layer via VC-12 into ATM processing board for statistical multiplexing into ATM VC-4, which is then transmitted transparently via the convergence layer or via ATM vp-ring to the RNC node, Connected to the RNC through the STM-1 interface. In this way, ATM data processing can be realized only through a small number of converging nodes in the whole network, and the bandwidth utilization is greatly improved by the statistical multiplexing of the bandwidths at each converging node. Using Netring series MSTP products to set up 3G mobile transmission network, it provides ATM service access, processing and transmission in a network, and can provide common transmission platform for various other services at the same time. In addition, the unified management of transmission and ATM is realized by using MSTP, which provides flexible bandwidth scheduling. In the access layer, we can make full use of the original base station's transmission equipment and E1 interface, only a small amount of investment in the convergence layer, while providing ATM service processing, the use of ATM statistical multiplexing to improve bandwidth utilization. Through MSTP to the original transmission network transformation, the realization network structure is more clear and reasonable, will greatly improve the network scalability and the flexible and efficient bandwidth provides the ability.

For the application of ATM STM-1 interface in some node-b, 622M group ring can be used in high business area node, through NetRing600 providing ATM STM-1 access and composing ATM vp-ring uploading to RNC. For the Low fields node, the NetRing600 provides ATM STM-1 access, and converts the aggregation of the IMA E1 to the aggregation node for ATM service, only using 155M group loop. The evolution of 3G mobile communication system to pure IP based on pure IP network is the direction of telecom development, IP with its simple and efficient features, in the telecommunications industry has been more and more attention. 3G R5 and future versions tend to be based on IP systems, netring products not only can support IP interface, but also for different businesses to provide the corresponding QoS guarantee. Because the current Ethernet technology is oriented to connectionless, there is not enough QoS guarantee mechanism. In order to introduce true QoS, it is necessary to introduce an intermediate intelligent adaptation layer between Ethernet and SDH to handle QoS of IP service. Therefore, UT Tatsu Kang's netring series products will gradually introduce RPR, MPLS mechanism, well to meet this demand.

With the increasing demand for data access, the 3G mobile communication system, which provides high-speed wireless data access, will be implemented. Therefore, in the construction of transmission network to fully consider the transmission requirements of the 3G system is very necessary, Netring series to mature SDH technology as the foundation, providing IP, ATM and other business processing capabilities, not only to meet the current GSM/GPRS network transmission requirements, It can also provide a comprehensive low-cost 3G transport solution based on ATM hosting technology, and be able to target the R5 and later versions of 3G network technology based on pure IP technology, and realize a migration path of the ideal basic transmission network to 3G, and complement the 3G mobile system.