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11 RNC Transport and NetworkingAbout This Chapter

This part describes the networking modes on the RNC side in terms of the transport andnetworking on the Iub, Iu-CS/Iu-PS/Iur, and Iu-BC interfaces and the RNC OM networking.

11.1 Transport and Networking on the Iub InterfaceThis part describes the interface boards and network solutions applicable to data transmissionbetween RNC and NodeB.11.2 Transport and Networking on the Iu/Iur InterfaceThis part describes the interface boards and network solutions applicable to data transmissionbetween the RNC and the CN or neighboring RNC.11.3 Transport and Networking on the Iu-BC InterfaceThis part describes the interface boards and network solutions applicable to data transmissionbetween the RNC and the CBC.11.4 RNC OM NetworkingThe RNC OM networking provides operation and maintenance for the RNC and NodeB.

RNCProduct Description 11 RNC Transport and Networking

Issue 02 (2007-08-15) Huawei Technologies Proprietary 11-1

11.1 Transport and Networking on the Iub InterfaceThis part describes the interface boards and network solutions applicable to data transmissionbetween RNC and NodeB.

11.1.1 Interface Boards for the IubThe Iub interface supports data transmission based on ATM, IP, or ATM/IP dual stack. Differenttypes of interface board are applicable to different modes of data transmission.11.1.2 ATM-Based Networking on the Iub InterfaceIn ATM-based networking on the Iub interface, the RNC and the NodeB communicate basedon the ATM protocol stack.11.1.3 IP-Based Networking on the Iub InterfaceIn IP-based networking on the Iub interface, the RNC and the NodeB communicate based onthe IP protocol stack.11.1.4 ATM/IP-Based Networking on the Iub InterfaceIn ATM/IP-based networking on the Iub interface, the RNC and the NodeB communicate basedon the ATM/IP dual stack, that is, based on the ATM and IP protocol stacks at the same time.11.1.5 Satellite-Based Networking on the Iub InterfaceIn satellite-based networking on the Iub interface, the RNC and the NodeB communicate throughthe satellite.11.1.6 2G/3G Concurrent Transmission and NetworkingIn 2G/3G concurrent transmission, the 2G and 3G information share transmission resources.This part describes the networking for such transmission.

11.1.1 Interface Boards for the IubThe Iub interface supports data transmission based on ATM, IP, or ATM/IP dual stack. Differenttypes of interface board are applicable to different modes of data transmission.

ATM-Based Iub Interface BoardsThe following types of board are available for the ATM-based Iub interface:l AEUal AOUal UOIa

IP-Based Iub Interface BoardsThe following types of board are available for the IP-based Iub interface:l PEUal FG2al GOUa

11 RNC Transport and NetworkingRNC

Product Description

11-2 Huawei Technologies Proprietary Issue 02 (2007-08-15)

ATM/IP-Based Iub Interface BoardsOver the Iub interface based on the ATM/IP dual stack, the RNC can communicate with a NodeBthrough ATM and IP transport at the same time.The following interface boards are available for the ATM transport option on the Iub interface:l AEUal AOUal UOIa

The following interface boards are available for the IP transport option on the Iub interface:l FG2al GOUa

NOTE

When data transmission based on the ATM/IP dual stack applies, the IP transport option is mainly used tocarry high-speed large-throughput traffic, such as HSDPA and HSUPA. The PEUa board, however, doesnot meet the transmission requirements of such services. Therefore, the PEUa board is usually not appliedto ATM/IP dual stackbased transport.

11.1.2 ATM-Based Networking on the Iub InterfaceIn ATM-based networking on the Iub interface, the RNC and the NodeB communicate basedon the ATM protocol stack.

Scenario of the NetworkingThe RNC and the NodeB can communicate with each other through the existing PDH, SDH, orATM network.

ATM Networking Based on PDHIn this networking mode, the RNC uses the AEUa as the Iub interface board.Figure 11-1 shows the ATM networking based on PDH. E1/T1 ports on the RNC serve the ATMtransport.

Figure 11-1 ATM networking based on PDH

NOTE

If the NodeBs are distributed on different PDH rings, additional ADM/DXC devices are required.



ATM Networking Based on ATM over E1/T1 over SDHIn this networking mode, the AOUa board of the RNC serves as the Iub interface board andsupports board backup and MSP 1:1 optical port backup.Figure 11-2 shows the ATM networking based on ATM over E1 over SDH. Channelized STM-1optical ports on the RNC serve the ATM transport.

Figure 11-2 ATM networking based on ATM over E1/T1 over SDH

The SDH network converges the E1 traffic, which travels from multiple NodeBs, to achannelized STM-1 optical port. The network then communicates with the RNC through achannelized STM-1 optical port.

NOTE

If the NodeBs are distributed on different SDH rings, additional ADM/DXC devices are required.

ATM Networking Based on ATM over SDHIn this networking mode, the UOIa board of the RNC serves as the Iub interface board andsupports board backup and MSP 1+1 or MSP 1:1 optical port backup.Figure 11-3 shows the ATM networking based on ATM over SDH. Unchannelized STM-1optical ports on the RNC serve the ATM transport.

Figure 11-3 ATM networking based on ATM over SDH

The ATM network converges the E1/T1 traffic, which travels from multiple NodeBs, to anSTM-1 port. The ATM network then connects to the unchannelized optical port on the UOIaboard of the RNC.


Product Description


Advantages of the NetworkingThe mature ATM-based networking on the Iub interface ensures ATM transmission bandwidth,has a QoS guarantee mechanism, and features security and reliability. The telecom operatorscan make efficient use of the existing PDH, SDH, or ATM transmission resources.The advantages of each type of networking are as follows:l ATM Networking Based on PDH

This type of networking enables the telecom operators to use the existing PDH transmissionresources.

l ATM Networking Based on ATM over E1/T1 over SDHThis type of networking requires simple cable connections, features convenient equipmentinstallation and maintenance, and supports MSP 1:1 backup.

l ATM Networking Based on ATM over SDHThis type of networking requires simple cable connections, features convenient equipmentinstallation and maintenance, and supports MSP 1+1 backup. The ATM switch convergesE1 traffic, which travels from multiple NodeBs, to an STM-1 device, thus enablingstatistical multiplexing, obtaining convergence gain, and saving transmission resources.

Disadvantages of the NetworkingCompared with IP-based networking, ATM-based networking on the Iub interface has a highcost.

11.1.3 IP-Based Networking on the Iub InterfaceIn IP-based networking on the Iub interface, the RNC and the NodeB communicate based onthe IP protocol stack.

Scenario of the NetworkingThe RNC and the NodeB can communicate with each other through the existing PDH, SDH,MSTP, or data network.

IP Networking Based on PDH/SDHIn this networking mode, the RNC uses the PEUa as the Iub interface board.Figure 11-4 shows the IP networking based on PDH/SDH. E1/T1 ports on the RNC serve theIP transport.

Figure 11-4 IP networking based on PDH/SDH



The RNC accesses the PDH/SDH networks through E1/T1 ports and transmits data in IP overMLPPP/PPP over E1/T1 mode. The NodeB can obtain timing signals from the E1/T1 links.The PDH/SDH network allows transparent transport for E1/T1 data. The network guaranteesreliability, security, and QoS for the transmission of Iub interface data.

IP Networking Based on MSTPIn this networking mode, the FG2a or GOUa board of the RNC serves as the Iub interface boardand supports board backup and FE/GE port backup.Figure 11-5 shows the IP networking based on MSTP. FE/GE ports on the RNC serve the IPtransport.

Figure 11-5 IP networking based on MSTP

The MSTP device on the RNC side encapsulates Ethernet frames into a VC trunk and transmitsthem in transparent mode to the MSTP device on the NodeB side through the MSTP network.The MSTP device on the NodeB side then retrieves the Ethernet frames and sends them to theNodeB through the FE/GE ports.

IP Networking Based on Data NetworkIn this networking mode, the FG2a or GOUa board of the RNC serves as the Iub interface boardand supports board backup and FE/GE port backup.Figure 11-6 shows the IP networking based on data network. FE/GE ports on the RNC servethe IP transport.


Product Description


Figure 11-6 IP networking based on data network

The RNC accesses the router through the FE/GE port on the FG2a or GOUa board andcommunicates with the NodeBs through IP, Multiprotocol Label Switching (MPLS), or VirtualPrivate Network (VPN).

NOTE

MPLS and VPN help guarantee security of the IP transport.

IP Networking Based on Hybrid IP TransportIn this networking mode, the PEUa and FG2a/GOUa boards of the RNC serve as the Iub interfaceboards and support PEUa board backup, FG2a/GOUa board backup, and FE/GE port backup.Figure 11-7 shows the IP networking based on hybrid IP transport. E1/T1 ports and FE/GE portson the RNC serve the hybrid IP transport.

Figure 11-7 IP networking based on hybrid IP transport

The RNC and the NodeB in this networking mode communicate with each other throughdifferent transport networks, which carry different types of data. The networks are described asfollows:



l The PDH/SDH network transmits data of real-time services with high QoS requirementson the Iub interface. The data can be NBAP signaling, RRC control signaling, and voicedata. The NodeB obtains timing signals through the PDH/SDH network.

l The data network transmits data of services with low QoS requirements. The data can beHSDPA data, HSUPA data, or R99 background service data.

Advantages of the Networkingl IP-based access features lower cost than ATM-based access.l IP networking provides high bandwidth to meet the requirements of high-speed data

services, such as HSDPA and HSUPA.l For data services, transport in IP over E1/T1 mode features higher efficiency than transport

in ATM over E1/T1 mode.l IP transport leads the development of transport technologies.

11.1.4 ATM/IP-Based Networking on the Iub InterfaceIn ATM/IP-based networking on the Iub interface, the RNC and the NodeB communicate basedon the ATM/IP dual stack, that is, based on the ATM and IP protocol stacks at the same time.With the development of data services, especially with the introduction of High Speed DownlinkPacket Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), the Iub interface hasan increasing demand for the bandwidth. A pure ATM network causes a high cost. IP transportsaves the transmission cost but provides a lower guarantee of QoS than ATM transport does.Therefore, the ATM/IP dual stack is introduced. Services with different QoS requirements aretransmitted on different types of network.

Description of the NetworkingThe ATM/IP dual stackbased Iub interface allows hybrid transport of services that havedifferent QoS requirements. High-QoS services, such as voice services, streaming services, andthe signaling, are transmitted on the ATM network. Low-QoS services, such as HSDPA andHSUPA services, are transmitted on the IP network.Figure 11-8 shows the ATM/IP dual stackbased networking on the Iub interface.

Figure 11-8 ATM/IP dual stackbased networking on the Iub interface


Product Description


To support this networking, the RNC is configured with both ATM and IP interface boards. TheATM interface board can be the AEUa, AOUa, or UOIa. The IP interface board can be the FG2aor GOUa.l The ATM interface board connects to the ATM network through the E1/T1/channelized

STM-1 port.l The IP interface board connects to the IP network through the FE/GE port.The NodeB connects to the ATM and IP networks through its ATM and IP interface boardsrespectively.

Advantages of the Networkingl The ATM network guarantees the QoS.l The IP network reduces the transmission cost and meets the requirement of high-speed data

services for high bandwidth on the Iub interface.

Disadvantages of the NetworkingThe ATM/IP dual stackbased networking requires maintenance of both ATM and IP networks.This increases the difficulty in and the cost for network maintenance to a certain extent.

11.1.5 Satellite-Based Networking on the Iub InterfaceIn satellite-based networking on the Iub interface, the RNC and the NodeB communicate throughthe satellite.

Scenario of the NetworkingUsually, the RNC and the NodeB communicate with each other through a land-based transportsystem, such as a PDH, SDH, MSTP, microwave, ATM, or IP network. On coastal islands or inremote, sparsely-populated, or uninhibited areas, no land-based transport system is available,and it is difficult to deploy such a system. In such a situation, to enable the RNC to communicatewith remote NodeBs, satellite-based transmission applies.

Description of the NetworkingFigure 11-9 shows the satellite-based networking on the Iub interface.



Figure 11-9 Satellite-based networking on the Iub interface

The satellite transport network between the RNC and the NodeBs consists of the communicationssatellite and the earth stations. The RNC should be equipped with an earth station. The same istrue for each NodeB.l The communications satellite usually refers to a geosynchronous satellite.l The earth station can be a large- or small-scaled station.

A large-scaled earth station, such as a large-scaled national or internationalcommunication station, uses the large-aperture antenna to transmit high-speed data. Alarge-scaled earth station causes a high cost. User data should be converged on the earthstation through terrestrial communication networks before satellite communication. A small-scaled earth station, such as a Very Small Aperture Terminal (VSAT), uses the

small-aperture antenna. The equipment features low cost and easy deployment.NOTEThe interface between an earth station and the RNC or NodeB should comply with the ITU-T G.703recommendations.

Satellite Transmission BandsSatellite transmission usually uses the C or Ku band. Table 11-1 describes the frequency rangesand features of the two bands.

Table 11-1 Satellite transmission bandsBand Frequency Range DescriptionC l 3.7 GHz to 4.2 GHz

l 5.925 GHz to 6.425 GHzl Small atmospheric absorption lossl Little sensitivity to rainfalll Sensitive to interference from terrestrial

intra-band microwave communicationl Large antenna aperture


Product Description


Band Frequency Range DescriptionKu l 11.7 GHz to 12.2 GHz

l 14 GHz to 14.5 GHzl Sensitive to rainfall, snowfall, and fogsl Sensitive to few intra-band interference

sourcesl Flexible application zonesl Small antenna aperture

Advantages of the Networkingl This networking features wide coverage and easy deployment. It is insensitive to

topographic changes. The satellite receiver can be built almost anywhere on the earth.l The mobility is satisfactory. This networking can quickly satisfy the deployment demand

in special areas or emergency communication scenarios.l Bandwidth adjustment is flexible.

Disadvantages of the Networkingl The cost for building a satellite communication system and leasing satellite links is high.l The transmission quality is sensitive to climatic and environmental changes. Errors in

transmission may lead to degradation of voice or data service quality or sharp decline oftransmission efficiency.

l Compared with terrestrial transmission, satellite transmission has a high loopback delay of500 ms to 700 ms. A high delay may result in call failure.

11.1.6 2G/3G Concurrent Transmission and NetworkingIn 2G/3G concurrent transmission, the 2G and 3G information share transmission resources.This part describes the networking for such transmission.The fractional and timeslot cross connection functions provided by the AEUa board enable theRNC to share E1/T1 transmission resources with the 2G equipment.

Fractional FunctionThe fractional function converts ATM cells transmitted in the RNC to timeslot signals that aretransmitted through idle E1/T1 timeslots. One E1 frame has 32 timeslots numbered from 0 to31. All the timeslots except timeslot 0 are available for service data transmission. One T1 framehas 24 timeslots numbered from 1 to 24. All the timeslots are available for service datatransmission. The RNC should negotiate with the peer equipment about which timeslots carrythe ATM cells.The fractional function consists of fractional ATM and fractional IMA. In fractional ATM mode,multiple idle timeslots can be selected to carry data. In fractional IMA mode, multiple fractionalIMA links are logically bound to a group and each fractional IMA link uses the same quantityof idle timeslots to carry data.

Timeslot Cross ConnectionThe timeslot cross connection provides transfer connections between 2G and 3G equipment.Thus, the 2G and 3G data transmission share E1/T1 transmission resources. The networking



modes for 2G/3G concurrent transmission vary with the types of timeslot cross connectionequipment.

Fractional-Based Networking with Timeslot Cross Connection on 2G EquipmentTo allow 2G/3G concurrent transmission in this networking mode, the 3G equipment (RNC andNodeB) provides the fractional function and the 2G equipment (BSC and BTS) provides thetimeslot cross connection function. Figure 11-10 shows the networking.

Figure 11-10 Fractional-based networking with timeslot cross connection on 2G equipment

The 3G equipment connects to the 2G equipment through the E1/T1 link. The 2G equipmentcross-connects the timeslots on the 3G E1/T1 link to the idle timeslots on the 2G E1/T1 link, soas to enable 2G/3G concurrent transmission.

Fractional-Based Networking with Timeslot Cross Connection on 3G EquipmentTo allow 2G/3G concurrent transmission in this networking mode, the 3G equipment (RNC andNodeB) provides the fractional and timeslot cross connection functions. Figure 11-11 showsthe networking.


Product Description


Figure 11-11 Fractional-based networking with timeslot cross connection on 3G equipment

The 2G equipment connects to the 3G equipment through the E1/T1 link. The 3G equipmentcross-connects the timeslots on the 2G E1/T1 link to the idle timeslots on the 3G E1/T1 link, soas to enable 2G/3G concurrent transmission.

Fractional-Based Networking with Timeslot Cross Connection on ExternalEquipment

To allow 2G/3G concurrent transmission in this networking mode, the 3G equipment (RNC andNodeB) provides the fractional function and the external equipment provides the timeslot crossconnection function. Figure 11-12 shows the networking.

Figure 11-12 Fractional-based networking with timeslot cross connection on external equipment

The 3G equipment and the 2G equipment connect to the Digital Cross-connect equipment (DXC)through the E1/T1 links. The DXC cross-connects the 2G and 3G E1/T1 timeslots to the timeslotson one E1/T1 link, so as to enable 2G/3G concurrent transmission.



11.2 Transport and Networking on the Iu/Iur InterfaceThis part describes the interface boards and network solutions applicable to data transmissionbetween the RNC and the CN or neighboring RNC.

11.2.1 Interface Boards for the Iu/IurThe Iu and Iur interfaces support ATM transport and IP transport. Different types of interfaceboard are applicable to different modes of data transmission.11.2.2 Networking Differences in 3GPP Protocol ReleasesThe networking on the Iu-CS interface varies with the CS domain equipment in the Core Network(CN) as specified by 3GPP R99 and R4/R5/R6.11.2.3 ATM-Based Networking on the Iu/Iur InterfaceIn ATM-based networking on the Iu or Iur interface, the RNC and the CN or neighboring RNCcommunicate based on the ATM protocol stack.11.2.4 IP-Based Networking on the Iu/Iur InterfaceIn IP-based networking on the Iu or Iur interface, the RNC and the CN or neighboring RNCcommunicate based on the IP protocol stack.

11.2.1 Interface Boards for the Iu/IurThe Iu and Iur interfaces support ATM transport and IP transport. Different types of interfaceboard are applicable to different modes of data transmission.

ATM-Based Iu/Iur Interface BoardsThe following types of board are available for the ATM-based Iu-CS or Iur interface:l UOIal AEUal AOUa

NOTE

Based on the traffic, the Iu-CS and Iur interfaces usually use the UOIa optical interface board that supportshigh traffic, and the Iub interface uses the AEUa or AOUa board that supports low traffic.

When ATM transport applies to the Iu-PS interface, only the UOIa can serve as the interfaceboard.

IP-Based Iu/Iur Interface BoardsThe following types of board are available for the IP-based Iu-CS or Iur interface:l FG2al GOUal PEUa

NOTE

Based on the traffic, the Iu-CS and Iur interfaces usually use the FG2a or GOUa board that supports hightraffic, and the Iub interface uses the PEUa board that supports low traffic.


Product Description


When IP transport applies to the Iu-PS interface, only the FG2a and the GOUa can serve as theinterface board.

11.2.2 Networking Differences in 3GPP Protocol ReleasesThe networking on the Iu-CS interface varies with the CS domain equipment in the Core Network(CN) as specified by 3GPP R99 and R4/R5/R6.

Release 99As specified by 3GPP R99, the CS domain of the CN adopts the sole MSC to process CS controlplane and user plane data. The RNC directly connects to the MSC over the Iu-CS interface, asshown in Figure 11-13.

Figure 11-13 Iu-CS networking in R99

Releases 4/5/6As specified by 3GPP R4/R5/R6, the CS domain of the CN adopts the MSC server and the MGWto process CS control plane and user plane data respectively.l The MSC server performs the control function. It mainly processes RANAP signaling on

the Iu-CS control plane.l The MGW performs the bearer function. It mainly processes user plane data and ALCAP

signaling on the Iu-CS interface.The only signaling communication between the RNC and the MSC server requires a lowbandwidth. Therefore, no direct connection between the RNC and the MSC server exists incommon cases. Instead, they communicate through the signaling forwarding at the MGW, asshown in Figure 11-14.

Figure 11-14 Iu-CS networking in R4/R5/R6



11.2.3 ATM-Based Networking on the Iu/Iur InterfaceIn ATM-based networking on the Iu or Iur interface, the RNC and the CN or neighboring RNCcommunicate based on the ATM protocol stack.

Scenario of the NetworkingThe RNC and the CN or neighboring RNC can communicate with each other through the existingSDH or ATM network.

Networking Based on SDH with MSP Backup Between Optical PortsIn this networking mode, the UOIa board of the RNC serves as the Iu/Iur interface board. TheRNC accesses the SDH network through the unchannelized STM-1 optical port on the UOIaboard.Figure 11-15 shows the networking based on SDH with MSP backup between optical ports.

Figure 11-15 Networking based on SDH with MSP backup between optical ports

In this networking mode, each Iu-CS, Iu-PS, or Iur interface requires a pair of STM-1 opticalcables for MSP 1+1 or MSP 1:1 backup. In a case other than direct connection between the RNCand the MSC or SGSN, the section-specific MSP backup at the RNC protects only the opticalchannels between the RNC and the ADM, instead of all those between the RNC and the MSCor SGSN.

Networking Based on SDH with Load Sharing Between Optical PortsIn this networking mode, the UOIa board of the RNC serves as the Iu/Iur interface board. TheRNC accesses the SDH network through the unchannelized STM-1 optical port on the UOIaboard.


Product Description


Figure 11-16 shows the networking based on SDH with load sharing between optical ports.

Figure 11-16 Networking based on SDH with load sharing between optical ports

In this networking mode, the two UOIa boards for the Iu or Iur interface are not configured forbackup. The Iu/Iur control plane PVCs are shared by two optical ports on different UOIa boards.The same is true for the Iu/Iur user plane PVCs. Thus, the two optical ports share the load. Ifone of the optical ports is faulty, the services carried on it are disrupted. Then the traffic on theIu or Iur interface reduces by half.

Networking Based on SDH with STM-1 Shared by Iu and IurIn this networking mode, the UOIa board of the RNC serves as the Iu/Iur interface board. TheRNC accesses the SDH network through the unchannelized STM-1 optical port on the UOIaboard.Figure 11-17 shows the networking based on SDH with STM-1 shared by Iu and Iur.



Figure 11-17 Networking based on SDH with STM-1 shared by Iu and Iur

Usually, the traffic on the Iur interface is low. Therefore, when the RNC connects to a numberof Iur interfaces where traffic is low, the Iu and Iur interfaces can share an STM-1 transmissionresource to transmit data before the MSC separates the Iu PVC from the Iur PVC by using VCor VP switching.

Networking Based on ATMIn this networking mode, the UOIa of the RNC serves as the Iu/Iur interface board. The RNCaccesses the ATM network through the unchannelized STM-1 optical port on the UOIa.Figure 11-18 shows the networking based on ATM.


Product Description


Figure 11-18 Networking based on ATM

In this networking mode, each Iu-CS, Iu-PS, or Iur interface requires a pair of STM-1 opticalcables for MSP 1+1 or MSP 1:1 backup. The MSP backup is section-specific. The RNC adoptsMSP backup to protect only the optical channels between the RNC and the ATM switch insteadof all those between the RNC and the MSC or SGSN. In the case of direct connection on the Iu-CS or Iu-PS interface, however, the MSP backup at the RNC protects all the connections betweenthe RNC and the MSC or SGSN.

NOTE

l STM-1 sharing between the Iu and Iur interfaces is applicable to the ATM-based networking. In thiscase, the Iu and Iur interfaces share a pair of STM-1 optical cables to transmit data before the ATMswitch separates the Iu PVC from the Iur PVC by using VC or VP switching.

l Load sharing is also applicable to the ATM-based networking. This networking mode is similar to thatof the SDH-based networking with load sharing between optical ports.

Advantages of the NetworkingThe advantages of each type of networking are as follows:l Networking based on SDH with MSP backup between optical ports

The transmission backup provided by this network solution helps guarantee hightransmission reliability.

l Networking based on SDH with load sharing between optical portsThis network solution saves the optical ports and cables that serve the data transmissionbetween the RNC and the ADM, thus improving the optical resource utilization.

l Networking based on SDH with STM-1 shared by Iu and IurIn the case of a large number of Iur interfaces, if each Iur interface occupies one STM-1port, there is high demand for transmission resources and the resource utilization is low.The SDH-based networking with STM-1 shared by Iu and Iur is resource-effective.



l Networking based on ATMThe Iu, Iur, and Iub interface can share a port or board for data transmission, thus savingthe transmission resources and improving resource utilization.

Disadvantages of the NetworkingThe disadvantages of each type of networking are as follows:l Networking based on SDH with MSP backup between optical ports

For transmission backup, this network solution requires a double share of optical port andcable resources.

l Networking based on SDH with load sharing between optical portsThis network solution does not provide transmission backup, thus failing to achieve hightransmission reliability. If an optical port or cable is faulty, the ongoing services carried onthe faulty part are disrupted.

l Networking based on SDH with STM-1 shared by Iu and IurThis network solution requires VC/VP switching at the MSC, thus increasing the load ofthe MSC.

l Networking based on ATMATM equipment has a high cost and ATM networks take an shrinking share. It is notrecommended to build extra ATM networks for Iu/Iur transmission.

11.2.4 IP-Based Networking on the Iu/Iur InterfaceIn IP-based networking on the Iu or Iur interface, the RNC and the CN or neighboring RNCcommunicate based on the IP protocol stack.

Scenario of the NetworkingThe RNC and the CN or neighboring RNC can communicate with each other through the IPnetwork.

Single-Homing Layer 3 NetworkingIn this networking mode, the FG2a or GOUa board of the RNC serves as the Iu or Iur interfaceboard and supports board backup and FE/GE port backup.Figure 11-19 shows the single-homing layer 3 networking. FE/GE ports on the RNC serve theIP transport.


Product Description


Figure 11-19 Single-homing layer 3 networking

In this networking mode, the FE/GE ports of the RNC are configured for backup. The activeand standby FE/GE ports of the RNC connect to the Provider Edge (PE), which further connectsto the data network. The active and standby FE/GE ports of the RNC share one IP address, thatis, IP1-1. The PE configures the active and standby ports of the RNC in one VLAN and usesone interface IP address of the VLAN, that is, IP1-0.

NOTE

The GE optical ports on the GOUa board are applicable to the scenario where the RNC is far away fromthe PE, and the FE/GE electrical ports on the FG2a board are applicable when the distance between theRNC and the PE is within 100 meters.

Dual-Homing Layer 3 NetworkingIn this networking mode, the FG2a or GOUa board of the RNC serves as the Iu or Iur interfaceboard and supports board backup and FE/GE port backup.Figure 11-20 shows the dual-homing layer 3 networking. FE/GE ports on the RNC serve the IPtransport.



Figure 11-20 Dual-homing layer 3 networking

In this networking mode, the FE/GE ports of the RNC are configured for backup. The activeand standby FE/GE ports of the RNC connect to two PEs, which further connect to the datanetwork. Complying with the Virtual Router Redundancy Protocol (VRRP), the two PEs provideredundancy-based protection for the data transmitted from the RNC. One PE connects to theother through two GE ports. Link Aggregation (LAG) is applied to the interconnection linksbetween the PEs to increase the bandwidth and reliability of the links. The active and standbyFE/GE ports of the RNC share one IP address, that is, IP1-1. The PEs configure the active andstandby ports of the RNC in one VLAN and use one virtual VRRP IP address, that is, IP1-0.

NOTEThe GE optical ports on the GOUa board are applicable to the scenario where the RNC is far away fromthe PE, and the FE/GE electrical ports on the FG2a board are applicable when the distance between theRNC and the PE is within 100 meters.

Direct Connection with Load SharingIn this networking mode, the FG2a or GOUa board of the RNC serves as the Iu or Iur interfaceboard, which directly connects to the MGW, SGSN, or neighboring RNC.Figure 11-21 shows the direct connection with load sharing. FE/GE ports on the RNC serve theIP transport.

Figure 11-21 Direct connection with load sharing

When the RNC and the MGW, SGSN, or neighboring RNC are located in the same equipmentroom, direct connection through FE/GE ports is applicable to the Iu or Iur interface. This network


Product Description


solution does not involve any extra transport network or equipment. In this networking mode,the FG2a or GOUa boards can work in board backup mode, and the FE/GE ports work in loadsharing mode to carry services.

Advantages of the NetworkingThe advantages of each type of networking are as follows:l Single-homing layer 3 networking

This network solution provides redundancy-based protection for FE/GE links. The singlePE saves networking cost.

l Dual-homing layer 3 networkingThis network solution provides redundancy-based protection not only for FE/GE links butalso for PE devices.

l Direct connection with load sharingThis network solution does not require any LAN switch or router, thus featuring lownetworking cost and high transmission reliability.

Disadvantages of the NetworkingThe disadvantages of each type of networking are as follows:l Single-homing layer 3 networking

The single PE cannot provide PE-level protection.l Dual-homing layer 3 networking

The dual PEs cause a high networking cost.l Direct connection with load sharing

This network solution does not provide redundancy for data transmission. A port failurewill lead to the decline of transmission capacity.

11.3 Transport and Networking on the Iu-BC InterfaceThis part describes the interface boards and network solutions applicable to data transmissionbetween the RNC and the CBC.

11.3.1 Interface Boards for the Iu-BCThe Iu-BC interface supports ATM transport and IP transport. Different types of interface boardare applicable to different modes of data transmission.11.3.2 ATM-Based Networking on the Iu-BC InterfaceIn ATM-based networking on the Iu-BC interface, the RNC and the CBC communicate basedon the ATM protocol stack.11.3.3 IP-Based Networking on the Iu-BC InterfaceIn IP-based networking on the Iu-BC interface, the RNC and the CBC communicate based onthe IP protocol stack.

11.3.1 Interface Boards for the Iu-BCThe Iu-BC interface supports ATM transport and IP transport. Different types of interface boardare applicable to different modes of data transmission.



ATM-Based Iu-BC Interface BoardsWhen applied with ATM transport, the Iu-BC interface shares the interface board UOIa withthe Iu-PS interface.

IP-Based Iu-BC Interface BoardsThe following types of board are available for the IP-based Iu-BC interface:l FG2al GOUa

11.3.2 ATM-Based Networking on the Iu-BC InterfaceIn ATM-based networking on the Iu-BC interface, the RNC and the CBC communicate basedon the ATM protocol stack.

Scenario of the NetworkingThe RNC and the CBC can communicate with each other through the SDH network.

Description of the NetworkingIn this networking mode, the UOIa board of the RNC serves as the Iu-BC interface board andsupports board backup and MSP 1+1 or MSP 1:1 optical port backup.Figure 11-22 shows the ATM-based networking on the Iu-BC interface. Unchannelized STM-1optical ports on the RNC serve the ATM transport.

Figure 11-22 ATM-based networking on the Iu-BC interface

In this networking mode, the RNC is connected to the CBC through the SGSN. On the Iu-BCinterface, usually only the FE port on the CBC server is connected to the SGSN, and an IPoAPVC is configured between the RNC and the SGSN. The SGSN performs route forwardingbetween the IPoA PVC and the FE link. When ATM transport is applied to the Iu-PS interface,this network solution makes efficient use of the physical transmission resources on the Iu-PSinterface.


Product Description


11.3.3 IP-Based Networking on the Iu-BC InterfaceIn IP-based networking on the Iu-BC interface, the RNC and the CBC communicate based onthe IP protocol stack.

Scenario of the NetworkingThe RNC and the CBC can communicate with each other through the IP network.

Description of the NetworkingIn this networking mode, the FG2a or GOUa board of the RNC serves as the Iu-BC interfaceboard and supports board backup and FE/GE port backup.Figure 11-23 shows the IP-based networking on the Iu-BC interface. FE/GE ports on the RNCserve the IP transport.

Figure 11-23 IP-based networking on the Iu-BC interface

When IP transport is applied to the Iu interface on the RNC side, the RNC and the CBC candirectly connect to the IP network, which provides a connection on the Iu-BC interface.Physically, an Iu-BC interface can share an FE/GE port at the RNC with an Iu interface, becauseof the low traffic on the Iu-BC interface. For details about the physical connections for IPtransport on the Iu interface, refer to 11.2.4 IP-Based Networking on the Iu/Iur Interface.

11.4 RNC OM NetworkingThe RNC OM networking provides operation and maintenance for the RNC and NodeB.Figure 11-24 shows the RNC OM networking.



Figure 11-24 RNC OM networking

As shown in Figure 11-24, either local or remote maintenance is applicable to the RNC andNodeB. Local maintenance is performed on the LMT, and remote maintenance is performedthrough the OM network. The RNC-NodeB OM channel is configurable. Through the OMchannel, remote maintenance of the NodeB can be performed on the Network ManagementSystem (NMS), M2000, or NodeB LMT.


Product Description


11 RNC Transport and Networking11.1 Transport and Networking on the Iub Interface11.1.1 Interface Boards for the Iub11.1.2 ATM-Based Networking on the Iub Interface11.1.3 IP-Based Networking on the Iub Interface11.1.4 ATM/IP-Based Networking on the Iub Interface11.1.5 Satellite-Based Networking on the Iub Interface11.1.6 2G/3G Concurrent Transmission and Networking

11.2 Transport and Networking on the Iu/Iur Interface11.2.1 Interface Boards for the Iu/Iur11.2.2 Networking Differences in 3GPP Protocol Releases11.2.3 ATM-Based Networking on the Iu/Iur Interface11.2.4 IP-Based Networking on the Iu/Iur Interface

11.3 Transport and Networking on the Iu-BC Interface11.3.1 Interface Boards for the Iu-BC11.3.2 ATM-Based Networking on the Iu-BC Interface11.3.3 IP-Based Networking on the Iu-BC Interface

11.4 RNC OM Networking

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