1. 10/1551-HRA 901 16 Uen Rev BTechnical Product DescriptionMarconi LH 2.5DESCRIPTION

2. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20092 (125) Copyright Ericsson AB 2009. All rights reserved.DisclaimerNo part of this document may be reproduced in any form without the written permission ofthe copyright owner.The contents of this document are subject to revision without notice due to continuedprogress in methodology, design and manufacturing. Ericsson shall have no liability for anyerror or damage of any kind resulting from the use of this document. 3. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20093 (125)Contents1 MARCONI LH OVERVIEW.................................................................................. 61.1 System Overview....................................................................................................................... 61.2 Marconi LH Features................................................................................................................. 81.3 Transmission Capacity ............................................................................................................. 91.4 Frequency Bands .................................................................................................................... 101.4.1 Utilization of the frequency pattern.................................................................................... 101.5 System Configurations ........................................................................................................... 121.5.1 Terminal and regenerator/repeater station........................................................................ 121.5.2 Space diversity .................................................................................................................. 131.5.3 CCDP operation (XPIC)..................................................................................................... 151.5.4 Radio Protection Switching................................................................................................ 161.5.5 Baseband Radio Protection Switching (1+1 MSP/APS and EQP).................................... 261.5.6 System configuration examples......................................................................................... 281.6 ATPC and RTPC....................................................................................................................... 351.7 Software Management ............................................................................................................ 371.8 Rack Design ............................................................................................................................. 392 SYSTEM COMPONENTS / SUB-SYSTEMS..................................................... 432.1 Overview................................................................................................................................... 432.2 BBU........................................................................................................................................... 462.2.1 STM-1/OC-3 module ......................................................................................................... 472.2.2 BPS module....................................................................................................................... 492.2.3 SOH module ...................................................................................................................... 492.2.4 EOW module ..................................................................................................................... 532.2.5 RPS module....................................................................................................................... 542.2.6 TMN module ...................................................................................................................... 552.2.7 ICC module........................................................................................................................ 552.2.8 MSP/APS module.............................................................................................................. 562.3 TRX Unit.................................................................................................................................... 562.3.1 Mechanical design of the TRX unit.................................................................................... 602.3.2 Signal processing in the TRX unit ..................................................................................... 602.3.3 FAN unit............................................................................................................................. 662.3.4 External interfaces............................................................................................................. 662.3.5 Signal processing features ................................................................................................ 702.3.6 Space diversity reception .................................................................................................. 712.4 Channel Branching Network (CBN) ....................................................................................... 75 4. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20094 (125)2.5 Antennas and Waveguides..................................................................................................... 802.5.1 Elliptical waveguides ......................................................................................................... 802.5.2 Antenna types.................................................................................................................... 813 OPERATION AND MAINTENANCE.................................................................. 843.1 Local Maintenance Terminal (LMT) ....................................................................................... 843.2 Direct Connection to the LMT Interface RS232 .................................................................... 853.3 Direct LAN/WAN Connection via TCP/IP............................................................................... 853.3.1 IP address information for Marconi LH.............................................................................. 863.4 Modem Link.............................................................................................................................. 874 MARCONI LH IN THE DATA COMMUNICATION NETWORK......................... 884.1 Integration into a TMN............................................................................................................. 884.1.1 Introduction ........................................................................................................................ 884.1.2 Introduction to the SISA network....................................................................................... 884.1.3 Network element addressing in the SISA network ............................................................ 904.1.4 Basic information on protocols .......................................................................................... 914.1.5 SISA protocols................................................................................................................... 924.1.6 Connection of Marconi LH to the ServiceOn Access System ........................................... 944.2 Protocol stacks of interfaces ................................................................................................. 954.2.1 QD2 interface..................................................................................................................... 954.2.2 Routing functionality .......................................................................................................... 974.3 DCN Operating Modes .......................................................................................................... 1004.3.1 Connection to an OSI network......................................................................................... 1004.3.2 Connection to a QD2 network ......................................................................................... 1014.3.3 Connection to an IP network ........................................................................................... 1024.3.4 Overview of DCN operating modes................................................................................. 1035 ADDRESSES FOR CONNECTION TO SERVICEON ACCESS ..................... 1055.1 Addresses for Direct QD2 Connection................................................................................ 1055.2 Addresses for OSI Transport ............................................................................................... 1055.2.1 TSAP addresses.............................................................................................................. 1055.2.2 NSAP addresses ............................................................................................................. 1065.2.3 SISA-V Gateway address................................................................................................ 1095.2.4 Internet addresses........................................................................................................... 1095.3 Addresses for IP Transport .................................................................................................. 1105.4 Addresses for IP Routing ..................................................................................................... 1105.5 Ethernet Address................................................................................................................... 1115.6 Summary of Address Settings ............................................................................................. 112 5. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20095 (125)6 APPLICATIONS .............................................................................................. 1136.1 Connection of Marconi LH to ServiceOn Access via a SISA-DCN ................................... 1136.1.1 Direction QD2 connection................................................................................................ 1136.1.2 Direct and indirect connection via QD2 using the ECC................................................... 1146.1.3 Setup of an OSI-DCN within a SISA-DCN ...................................................................... 1146.1.4 Managing further SISA-DCNs ......................................................................................... 1156.1.5 Interconnection of several SISA or QD2 sub-networks via the LAN ............................... 1166.2 Connection of the Marconi LH System to SOA via the OSI-DCN ..................................... 1176.2.1 Direct OSI connection...................................................................................................... 1176.2.2 Direct and indirect connection via OSI using the ECC.................................................... 1176.2.3 OSI-DCN.......................................................................................................................... 1186.2.4 Managing further SISA-DCNs ......................................................................................... 1186.2.5 Interconnection of several sub-networks via the LAN ..................................................... 1196.3 Connection of the Marconi LH System to SOA via the IP-DCN ........................................ 1206.3.1 Direct TCP/IP connection ................................................................................................ 1206.3.2 Direct and indirect connection via TCP/IP using the ECC .............................................. 1206.3.3 Setup of an OSI sub-network within a TCP/IP-DCN ....................................................... 1216.3.4 Managing further SISA-DCNs ......................................................................................... 1216.3.5 Interconnection of several sub-networks via the LAN ..................................................... 1226.3.6 Further direct TCP/IP connection (only local).................................................................. 1226.4 Heterogeneous SISA-, OSI- and IP-DCN ............................................................................. 1237 TECHNICAL CHARACTERISTICS OF MARCONI LH ................................... 1248 REFERENCES ................................................................................................ 125 6. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20096 (125)1 Marconi LH Overview1.1 System OverviewThe Marconi Long Haul (LH) microwave system transmits STM-1/OC-3 datastreams in the 4 GHz to 13 GHz frequency range.Marconi LH is provided in an ETSI version for Synchronous Digital Hierarchy(SDH) and an ANSI version for Synchronous Optical Network (SONET). Withfull SDH/SONET compatibility and integrated network management, it is analternative to cable-bound transmission systems.SDH/SONET is a standardized multiplex hierarchy that complements theformer Plesiochronous Digital Hierarchy (PDH) standard.SDH/SONET systems offer advanced setup and operation functions: Simple multiplexing procedure (no stuffing/destuffing); Common, network-wide reference clock; Direct access to individual channels; High bit rates for long-haul traffic links; High transmission capacity for network monitoring and control; Control by means of high-performance network management systems; Integration of already existing PDH structures; Uniform transmission network for all signal sources.The Marconi LH SDH/SONET microwave system is designed for indoor use.Large-scale integration permits up to ten STM-1/OC-3 radio channels to beaccommodated in a single ETSI or 19" rack (see schematic overview withoptional equipment in Fig. 1-1). 7. Technical Product DescriptionTRXTRXTRXTRXTRXTRXTRXTRXTRXRX-DivRX-MainTXPower Box NROMSBBU10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20097 (125)TRXBBUTXRX-MainRX-DivFig. 1-1 Example of Marconi LH system (10+0) or (9+1)* Note: The equipment variants listed in the table below can beimplemented.up to 10 transceivers(TRX Units)Channel-Branching Network(CBN)Power Box *OMS Multiplexer(optional) *Baseband Unit (BBU) with upto 5 STM-1/OC-3 channelsfor another 5 STM-1/OC-3channels 8. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20098 (125)Equipment variants:Power Box Max. number ofTRX UnitsNumber of OMS Multiplexers(optional)Power Box NRPower Box RPower Box R10105101Marconi LH complies with the standards and recommendations of national andinternational organizations such as ETSI, ANSI, ITU and CEPT. For moreinformation on Marconi LH standards and compliance, see Reference [4].1.2 Marconi LH FeaturesThese are some of the features in Marconi LH: Modular design; ETSI or 19" cabinets Up to 10 STM-1/OC-3 channels in one rack Expandable transmission capacity Extremely high system availability ( 99.99%) Full SDH/SONET compatibility Transparent regenerator operation for STM-1/OC-3 and STM-4/OC-12 Integrated 1+0 to 2x(9+1) or 1+1 HSB protection switching configurationfor high transmission performance All frequency bands adjustable via the transceiver (TRX) frequency-independentTX- RX synthesizers Integrated XPIC functionality for all RF bands Integrated space diversity combiner using automatic differential lengthcompensation Remote and Automatic Transmit Power Control (RTPC and ATPC ) Forward Error Correction (FEC) Q- or LAN-interface for TMN connection 9. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 20099 (125) Central monitoring and control possible with Ericsson ServiceOn tools Full software download compatibility Optional 1+1 Multiplex Section Protection (MSP)/Automatic ProtectionSwitching (APS) and Equipment Protection (EQP)1.3 Transmission CapacityThe Marconi LH (also referred to as MDRS155 EC) is designed for thetransmission of an STM-1/OC-3 signal at a bit rate of 55 Mbit/s per RF carrier.The baseband interface can be either an electrical or an optical interface.In combination with the DPU STM-4 (Data Processing Unit) for ETSI, or DPU622 (Data Processing Unit) for ANSI, as an STM-4/OC-12 regenerator,transparent transmission of a fully or partly occupied STM-4/OC-12 signal isalso possible.The unassigned bytes of the Section Overhead (SOH) are used for system-internalcontrol (ATPC, radio protection switching) and signalling services aswell as for up to 4x64 kbit/s and 1x2 or 2x2Mbit/s service channels for ETSIand 1x1.544 or 2x1.544 Mbit/s for ANSI.The standard operating mode is the RST (Regenerator Section Termination)mode (ITU-T G.782) which permits multiplex operation such as SNCP orMSP/APS in SDH/SONET ring networks.Thus, Marconi LH can be integrated in complex SDH/SONET networkstructures just like a "wireless cable".The MST mode (155 Mbit/s) or PDH mode (140 Mbit/s) is implemented by anexternal SDH/SONET multiplexer. 10. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200910 (125)1.4 Frequency BandsThe Marconi LH operates in the frequency bands from 4 GHz to 13 GHz(Table 1-1). Due to the synthesizer used in the transceiver (TRX), otherfrequency patterns can be easily implemented, if required.RF band Frequency range Standards4 GHz 3.4 to 4.2 GHz ITU-R Rec. F.382 / F.6355 GHz 4.4 to 5.0 GHz ITU-R Rec. F.1099 / F.746L6 GHz 5.6 to 6.45 GHz ITU-R Rec. F.383U6 GHz 6.4 to 7.1 GHz ITU-R Rec. F.3847 GHz 7.1 to 7.9 GHz ITU-R Rec. F.385 / ECC Rec. (02)068 GHz 7.7 to 8.5 GHz ITU-R Rec. F.386 / ECC Rec. (02)0611 GHz 10.6 to 11.7 GHz ITU-R Rec. F.38713 GHz 12.75 to 13.25 GHz ITU-R Rec. F.497Table 1-1 Frequency bands1.4.1 Utilization of the frequency patternThere are three basic patterns to allocate RF channel frequencies within anexisting frequency band. ACCP (adjacent-channel co-polarized pattern) Fig. 1-2) ACDP (adjacent-channel dual-polarized pattern) Fig. 1-3) CCDP (co-channel dual-polarized pattern Fig. 1-4)The actual frequency band uses either one of these patterns or a combinationof all three basic patterns.The channel spacing (CS) depends on the respective frequency band. Themodulation mode is selected depending on the channel spacing. The followingselection rules are applicable: 28 MHz CS 30 MHz for 128-QAM systems Channel spacing (CS) = 40 MHz for 64-QAM systemsThe use of channel-specific narrowband RF filters in the channel branchingnetwork (CBN) permits adjacent channel operation and thus an efficient use ofthe frequency band. 11. Technical Product Description1 2 3 4 510/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200911 (125)In case of a cross-polar channel connection with identical channel frequencies(Frequency Reuse) and a channel allocation according to the CCDP pattern,crosstalk effects between dual-polarized channels/signals are reduced toacceptable values by means of an internal XPIC (Cross-Polar InterferenceCanceller). This permits the transmission capacity to be doubled.CSRF channelfiltersPol. 1Pol. 2Fig. 1-2 ACCP operating modeCSRF channelfiltersPol. 1Pol. 2Fig. 1-3 ACDP operating mode 12. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200912 (125)CSRF channelfiltersPol. 1Pol. 2Fig. 1-4 CCDP operating mode1.5 System Configurations1.5.1 Terminal and regenerator/repeater stationA radio terminal is a digital microwave system providing a line interface and anRF interface. The line interface operates in the RST mode. A radio terminalmay have an unprotected (N+0) or a protected (N+1) configuration or a (1+1)hot standby configuration. A regenerator station (repeater) always providestwo RF interfaces. It can be operated with or without protection switching. Aregenerator station is composed of two radio terminals.Note: STM-1 is used to denote both STM-1 and OC-3, and MSP is used todenote both MSP and APS, in the images in this section.Radio System CBNSTM-1electr.or opt.STM-1electr.or opt.STM-1electr.or opt.Service channelsWayside channelsDCCr/DCCmFig. 1-5 Radio terminal 13. Technical Product DescriptionService channelsWayside channelsDCCr/DCCm10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200913 (125)Radio System CBNSTM-1electr. oropt.CBN Radio SystemFig. 1-6 Radio regenerator / Repeater1.5.2 Space diversitySpace diversity configurations are used to guarantee the requiredtransmission quality even in case of radio hops with lengths of 30 to 80 km orunder difficult propagation conditions. For this purpose, each transceiverincludes a main receiver and a diversity receiver. The diversity receiver issupplied via a separate antenna. An adaptive equalization is performed beforethe signals are merged by a combiner.The use of separate antennas for the main receiver and diversity receiverleads to different signal propagation times.This differential delay between the two receivers is measured andcompensated. This compensation is executed automatically by the combinerwithout requiring additional hardware.The diversity combiner is equipped with two adaptive filters for processing andanalyzing the main and diversity signals. This type of signal processingprovides better performance than classical combining methods such as IF combining with maximum power / max. gain criterion, IF combining with maximum power + distortion criterion, Baseband switching combiner. 14. Technical Product DescriptionService / operatingchannelsPS SOHSTM-110/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200914 (125)As shown in Fig. 1-7, a 1+0 radio terminal with space diversity requires onlyminimum hardware, since the space diversity receiver is integrated in the TRXunit.BBUCBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVCBNSTM-1electr. oropticalEOW TMNMain antennaDiv. antennaFig. 1-7 Radio terminal, 1+0 configuration with space diversity 15. Technical Product DescriptionService / operatingchannelsRX-MAINPS SOHSTM-1STM-110/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200915 (125)1.5.3 CCDP operation (XPIC)In case of radio channels allocated according to the CCDP channel pattern,cross-polar TRX units must exchange their Rx signals and supply acompensation signal for the cross-polar interference canceller (XPIC). Fig. 1-8shows a block diagram for a 2+0 radio terminal operated in the CCDP mode.Signal exchange between the TRX units takes place using two coaxial cables.CBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVSTM-1electr. oropticalTRX UnitTXBasebandProcessingRX-DIVOMTCBNPol. 1Pol. 2STM-1electr. oropticalBBUEOW TMNFig. 1-8 Radio terminal, 2+0 configuration with CCDP operation (XPIC) 16. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200916 (125)1.5.4 Radio Protection SwitchingA distinction is made here between equipment protection and lineprotection.1.5.4.1 GeneralIn equipment protection (1+1 HSB) configurations, the modules are doubled(redundant). The frequency and polarization level is identical.In operation, only one radio channel is active. In case of a signal failure orequipment defect occurring in the transmission path, the system switches overto the protection channel.In line protection (n+m) configurations, there are n operating and mprotection channels with different frequencies and polarizations.In operation, all radio channels are active. Signal transmission takes place viathe operating channels. In case of a fault, the system switches over to a freeprotection channel for the duration of the fault. This switchover is bit-error-free(hitless).1.5.4.2 1+1 hot standbyIn a 1+1 hot standby configuration (HSB, equipment protection), only oneSTM-1/OC-3 data signal is transmitted at a time. On the transmit side, thissignal is split up into two identical signals.In case of a fault or failure, switchover takes place to the redundanttransceiver. This switchover is performed by the RF switch which is in turntriggered by the RPS module. This lead to a short signal interruption.On the receive side, the incoming signal is applied to the Rx section of thetransceiver (active and redundant) via an RF coupler.The RPS module selects the better of the two receive signals. This selection isbit-error-free (Hitless Switching). 17. Technical Product DescriptionService / operatingchannelsPS SOHSTM-1 (OP1)STM-1 (PR)RPS10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200917 (125)Fig. 1-9 shows the block diagram of a 1+1 HSB configuration of a Marconi LH.BBU TRX UnitTXRX-MAINBasebandProcessingRX-DIVSTM-1electr. oropticalEOW TMNCBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVSWCPFig. 1-9 Radio terminal, 1+1 HSB configuration 18. Technical Product DescriptionService / operatingchannelsPS SOHSTM-1 (OP1)STM-1 (PR)RPS10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200918 (125)1.5.4.3 1+1 hot standby (space diversity)On radio hops with critical propagation conditions, space diversity isnecessary. A second antenna and the RF filters of the channel branchingnetwork (CBN) are required for this purpose (see Fig. 1-10). An alternativeapproach is shown in Fig. 1-11. With this configuration, RF couplers for thesignals received from the main antenna and diversity antenna are notrequired. Diversity combining is carried out using synchronous hitlessswitching between the STM-1/OC-3 data streams in the BBU.BBU TRX-UnitTXRX-MAINBasebandProcessingRX-DIVSTM1electr. oropticalEOW TMNCBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVSWCPCBNMain antennaDiv. antennaFig. 1-10 Radio terminal, 1+1 HSB config. with space diversity and RF coupler 19. Technical Product DescriptionService / operatingchannelsPS SOHSTM-1 (OP1)STM-1 (PR)RPS10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200919 (125)BBU TRX UnitTXRX-MAINBasebandProcessingRX-DIVSTM1electr. oropticalEOW TMNCBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVSWCBNMain antennaDiv. antennaFig. 1-11 Radio terminal, 1+1 HSB config. with space diversity w/o RF coupler1.5.4.4 Line protectionA radio system with line protection uses a number of operating channelsreferred to as OP1, ..., OPN (N > 1) and a number of protection channelscalled PR1, ..., PRM (M 1). In operation, signal transmission takes place viathe operating channels and is bit-error-free. In this case, the protectionchannels can be used for low-priority traffic transmission. This function isreferred to as "occasional traffic" (OT). The latter will be dropped as soon asswitchover from the operating channel to the corresponding protection channeltakes place in consequence of a fault. In case of degraded signal quality or afault occurring in one or several operating channels, performance thresholdsare used to select the channel with the highest priority and switch it over to abit-error-free protection channel.Marconi LH provides the RPS functionality with a single protection channel(M=1). Line protection configurations with up to 9 operating channels arepossible (i.e. max. (9+1) system configuration). If more than 9 operatingchannels must be protected, a second protection channel will be required. Inthis case, system configurations of max. 2x(9+1) can be implemented. 20. Technical Product DescriptionPS SOHSTM-1 (OP1)STM-1 (PR)RPS10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200920 (125)1.5.4.5 1+1 line protectionFig. 1-12 shows a radio terminal with 1+1 line protection without the possibilityto use the protection channel for occasional traffic (OT), i.e. low-priority trafficcannot be transmitted via this channel. In this case a data stream istransmitted via two RF channels with channel frequencies fOP1 and fPR1. Thesignals received are combined to one single data stream by the STM-1/OC-3module of the operating channel. This recombining results in the selection ofthe data stream with the lower bit error ratio, i.e. the higher quality signal. Thismeans, 1+1 line protection acts like a switching combiner where the diversityimprovement factor compared to an unprotected system depends on thechannel spacing f = fOP1 - fPR1 (see Fig. 1-14). Due to the frequency diversityeffect, the performance increases with the channel spacing f.If it is possible to sacrifice part of the improvement obtained through frequencydiversity, the protection channel may be configured to carry an STM-1/OC-3data stream which is dropped whenever the operating channel requiresprotection (see Fig. 1-13).BBU TRX UnitTXRX-MAINBasebandProcessingRX-DIVService / operatingchannelsEOW TMNCBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVSTM-1electr. oropticalFig. 1-12 Radio terminal, 1+1 configuration w/o occasional traffic 21. Technical Product DescriptionService / operatingchannelsPS SOHSTM-1 (OP1)STM-1 (PR)RPSf10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200921 (125)BBU TRX UnitTXRX-MAINBasebandProcessingRX-DIVSTM-1electr. oropticalEOW TMNCBNTRX UnitTXRX-MAINBasebandProcessingRX-DIVSTM-1electr. oropticalOccasionaltraffic (OT)Fig. 1-13 Radio terminal, 1+1 configuration with occasional trafficPol. 1Pol. 2OP1 PRfOP1 fPRFig. 1-14 Channel allocation for 1+1 line protection 22. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200922 (125)1.5.4.6 Line protection (1+1) with frequency diversityLine protection (1+1) with frequency diversity is a special line protectionconfiguration where the protection channel is exclusively provided for a singleoperating channel. The protection channel OT function is not provided.On the TX side, the STM-1/OC-3 signal is always transmitted simultaneouslyvia both the operating channel and protection channel. In trouble-freeoperation, identical signals are thus available at both RX-side inputs (OP andPR) of the synchronous signal selector switch in the operating channel. Assoon as a degradation is detected in the receive signal currently active, hitlessswitchover to the parallel signal takes place immediately. In contrast to normalline protection (n+1) configurations, the time required for the TX-side and RX-sidepreparation of signal paths is therefore not necessary.As long as a loss of signal is not detected in one of the two receive signals,the synchronous signal selector switch in the operating channel is controlledsoftware-independently by residual error pulses from the demodulator sectionof the two TRX units. This type of switching combination in the baseband isreferred to as frequency diversity.1.5.4.7 N+1 line protectionWith N+1 protection configurations (see Fig. 1-15, Fig. 1-16, Fig. 1-17), N+1STM-1/OC-3 data streams can be transmitted. The number of operatingchannels(N = 1 to 9) depends on the frequency pattern used. Thus, N operatingchannels share a common protection channel. Both the operating channelsand protection channel monitor their transmission quality and system status.Based on the results, each channel generates a so-called request level (RQL)which indicates the severity of the protection request for each channel. Due tothese RQLs, the N+1 radio system always knows as to which operatingchannel should be protected. 23. Technical Product DescriptionPS SOHSTM-1 (OP1)STM-1 (PR)RPSTX#1#2TXRX-MAINRX-MAINPS SOHSTM-1 (OP1)STM-1 (PR1)RPSTX#1#2TXRX-MAINRX-MAINPS SOHSTM-1 (OP9)ProcessingTX#6#7TXRX-MAINRX-MAIN10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200923 (125)BBU TRX UnitsTXRX-MAINBasebandProcessingRX-DIVService / operatingchannelsEOW TMNCBNSTM-1electr. oropticalSTM-1 (OP2)STM-1 (OP3)STM-1 (OP4)TXRX-MAINBasebandProcessingRX-DIVBasebandProcessingRX-DIVBasebandProcessingRX-DIV#3#4#5TXRX-MAINBasebandProcessingRX-DIVFig. 1-15 Radio terminal, (4+1) line protectionBBU1TRX UnitsTXRX-MAINBasebandProcessingRX-DIVEOW TMNSTM-1electr. oropticalSTM-1 (OP2)STM-1 (OP3)STM-1 (OP4)TXRX-MAINBasebandProcessingRX-DIVBasebandProcessingRX-DIVBasebandProcessingRX-DIV#3#4#5TXRX-MAINBasebandProcessingRX-DIVBBU2TRX UnitsTXRX-MAINBasebandProcessingRX-DIVService / operatingchannelsSTM-1 (OP5)RPSSTM-1electr. oropticalSTM-1 (OP6)STM-1 (OP7)STM-1 (OP8)TXRX-MAIN BasebandRX-DIVBasebandProcessingRX-DIVBasebandProcessingRX-DIV#8#9#10TXRX-MAINBasebandProcessingRX-DIVCBNCAN STM-1CBNFig. 1-16 Radio terminal, (9+1) line protection 24. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200924 (125)BBU TRX UnitsTXTXRX-MAINBasebandProcessing#1#2TXRX-MAINRX-DIVPS SOHSTM1 (OP1)STM1 (PR)RPSEOW TMNCBNSTM-1electr. oropticalSTM1 (OP2)STM1 (OP3)STM1 (OP4)TXRX-MAINBasebandProcessingRX-MAINRX-DIVBasebandProcessingRX-DIVBasebandProcessingRX-DIV#3#4#5TXRX-MAINBasebandProcessingRX-DIVBBUService / operatingchannelsSOH PSSTM1 (OP1)STM1 (OP2)STM1 (OP3)STM1 (OP4)STM1 (PR)RPSTMN EOW#1#2#3#4#5TXRX-MAINBasebandProcessingRX-DIVCBNFig. 1-17 Radio repeater; (4+1) line protection 25. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200925 (125)1.5.4.8 Line protection 2x(n+1)With line protection, the Marconi LH system initially supports only oneprotection channel and up to nine operating channels. If a microwave radioterminal has more than nine operating channels or in CCDP operation both polarizations shall have an own protection channel, the terminal can beconfigured for a second protection switching group with a separate protectionchannel. Regarding protection switching, both groups are completelyindependent of each other. For this reason, this line protection configuration isreferred to as 2x(n+1) configuration in the present document.Regarding protection switching, each channel is assigned a so-called RequestLevel (RQL) indicating the urgency of the corresponding protection switchingrequest. This RQL considers only the situation on the RX side and isinfluenced manually by the user configuration on the one hand andautomatically by the current internal RX signal quality criteria on the other.The protection channel (PR) assumes the Master function within a protectionswitching group. The operating channels (OPs) spontaneously signal eachchange of their request level via the CAN connection. This always leads to anew assessment of the nominal protection switching configuration. If thenominal configuration deviates from the actual configuration, the Masterinitiates a configuration update. This update must be performed both on theTX side of the far end and on the local RX side. In order to ensure highreliablity, protection switching communication with the far end takes place viaall channels in parallel. A media-specific byte in the RSOH of the STM-1/OC-3signal outgoing in the radio direction is used as communication channel.Besides the SDH/SONET-specific performance monitoring function, internalsignals of the digital equalizer and channel decoder available in thedemodulator of the radio unit are used to obtain automatic performancecriteria. Generally, these permit a very early detection of receive signaldegradations, so that in most cases switchover is possible before measurablebit errors or signal interruptions will occur.If required, the sensitivity and relevance of all four automatic performancecriteria can be configured individually for each channel via the OperatorTerminal PC. In addition, each channel can be assigned a high or lowprotection switching priority relevant in case of Master-internal conflicts (e.g.identical RQL of two channels).The protection channel can be used, if necessary, to transmit an own low-prioritydata signal. This low-priority transmission will be interrupted as soonas one of the operating channels is switched over to the protection channel(loose OT). However, the protection channel can also be used exclusively forthe transmission of an own signal (fixed OT). The OT status can be configuredvia the Operator Terminal PC. 26. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200926 (125)The guaranteed switching time for line protection (n+1) configurations is lessthan 10 ms including the time between the detection of a signal degradationand execution of synchronous switchover on the RX side.1.5.5 Baseband Radio Protection Switching (1+1 MSP/APS and EQP)This protection switching type in the BBU increases operational reliability ofthe Marconi LH system. It complements the protection already existing on theradio side (Radio Protection Switching).1+1 MSP/APS protects the line side against signal errors and the EQP in caseof a failure of a module or function of the STM-1/MSP or OC-3/APS module(switchover time MSP/APS 50 ms).This additional operational reliability can be implemented in an equipped BBUshelf by exchanging neighboring STM-1/OC-3 modules. A BBU canaccommodate up to 4 x (1+1) MSP/APS modules.The maximum configuration in a rack is 8+0, 8+1 or 2 x (4+1).Configurations supported:N+1, N = 1 ...82 x (N+1), N = 1 ... 8Configurations not supported:N + 01+1 HSB1+1 FDNote: - Preferred input (OP - top), PR - bottom- 9+1 or 2x(9+1) not possible- Mixed combinations (with/without MSP/APS) are also possible. 27. Technical Product Description1st MSP-Modul1. MSP/APS module2. MSP/APS module3. MSP/APS module4. MSP/APS module5. STM-1/OC-3 module10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200927 (125)Fig. 1-18 STM-1/MSP or OC-3/APS modules in a BBU for 4 x (1+1) 28. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200928 (125)1.5.6 System configuration examplesThe following sections describe some frequently used configuration examples.1.5.6.1 No redundancy (n+0): n 10Fig. 1-19 No redundancy (n+0): n 5 29. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200929 (125)If more than five STM-1/OC-3 channels are required (see Fig. 1-20), two BBUshelves have to be cascaded. The second BBU does not require a TMNmodule. In this case, however, the ICC module must be provided whichpermits Ethernet access to the TRX units associated with the STM-1/OC-3modules of this second BBU.Fig. 1-20 No redundancy (n+0): 6 n 10 30. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200930 (125)1.5.6.2 Line protection (n+1): n 9System configurations with up to four operating channels, i.e. OP01, OP02,OP03 and OP04, and one protection channel PR01 are implemented in asingle BBU shelf as depicted in Fig. 1-21. The RPS module provides therouting functionality required for the operating channels and protectionchannel.Fig. 1-21 Line protection (n+1): n 4 31. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200931 (125)Using a second BBU shelf system, configurations with up to nine operatingchannels are possible. The two BBU shelves exchange both STM-1/OC-3signals and switching information via a control bus.1.5.6.3 Line protection (1+1): Frequency diversityThe figure below shows a Marconi LH (1+1) with frequency diversity. In thiscase, only a single STM-1/OC-3 signal is transmitted in each direction viadifferent RF channels, i.e. at different channel frequencies. With the so-calleddiversity combining, switchover between the STM-1/OC-3 data streams ishitless and takes place simultaneously.Fig. 1-22 Line protection (1+1): Frequency diversity 32. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200932 (125)1.5.6.4 Line protection (1+1): Hot standbyThe figure below shows the modules of the BBU required for a (1+1) hotstandby configuration using an RF coaxial switch for the TX signal and an RFcoupler for the RX signals. The coaxial switch is controlled by the STM-1/OC-3module of the operating channel.Fig. 1-23 Line protection (1+1): Hot standby 33. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200933 (125)1.5.6.5 Line protection configuration with 1+1 MSP/APS and EQPFig. 1-24 Line protection configuration with 1+1 MSP/APS and EQP 34. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200934 (125)1.5.6.6 Line protection 9+1 with Ethernet and TDM interfaceFig. 1-25 Line protection 9+1 with Ethernet and TDM interface 35. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200935 (125)1.6 ATPC and RTPCIn order to permit frequency reuse in network nodes, the RF levels of thesignals transmitted must be reduced to avoid overshoots and reduceinterferences. The final objective consists in achieving a constant (specified)receive level at a relatively low input power level.The transmit level is controlled by the far-end receiver to obtain a constantreceive level.The Marconi LH can use both ATPC (Adaptive Transmit Power Control) andRTPC (Remote Transmit Power Control).DefinitionsThe RTPC function is used to adjust the maximum transmit power levelpossible. This level setting depends on the specific properties of the radio link.Usually, it is carried out only once and remains unchanged throughout theoperating lifetime of the system.The ATPC function is used to adjust the current transmit power leveldepending on the actual propagation conditions (e.g. link losses) of the radiochannel. Variations of the link attenuation due to varying fading conditions arereflected by the current receiver input level. Information pertaining to thereceived signal level (RSL) is then repeatedly relayed back to the far endsystem via a control channel embedded in the STM-1/OC-3 signal. Thisinformation is used to deduce the settings required for the current TX powerlevel.Fig. 1-26 shows as to how ATPC operation affects the current receive levelPRX and transmit level PTX depending on the link attenuation AL. Undernormal propagation conditions, the link attenuation is referred to as AL0. Up-fadingoccurs if the link attenuation is lower than the nominal value, whereasdown-fading occurs if it is higher than this value.In normal operation, we have a nominal receive level PRXNOM and a nominaltransmit level PTXNOM.If up-fading occurs, the ATPC function reduces the transmit level to maintainthe nominal receive level PRXNOM . At a certain point, however, the minimumvalue of the transmit level PTXMIN is reached. If in this case the linkattenuation keeps on decreasing, the transmit level is held at its minimumvalue and the receive signal level exceeds its nominal value PRXNOM.-In case of down-fading, the link attenuation AL increases and the ATPCfunction raises the transmit level PTX accordingly to maintain a constantreceive level PRXNOM. Using the ATPC function, the transmit level can beincreased to the maximum transmit power PTXMAX configured via RTPC. If thelink attenuation increases further, the transmit level remains constant and thereceive signal level decreases linearly with increasing link attenuation. 36. Technical Product DescriptionPTXNOMUp-fading Down-fading10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200936 (125)ALPRXRadio linkattenuationAL0PRXNOMAL0 ALRadio linkattenuationPTXPTXMAXPTXMIN11Fig. 1-26 Transmit and receive power vs. radio link attenuationThe ATPC function can be disabled, if required. In this case the TRX unittransmits at the constant maximum power PTXMAX initially configured viaRTPC. 37. Technical Product DescriptionSTM-1 TTRRXX SSTSTMTM-M1-1-1 TTRRXX10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200937 (125)1.7 Software ManagementOverviewThe Marconi LH is composed of the following eight software modules/sub-systems: TMN module STM-1/OC-3 module SOH module RPS module EOW module BPS module ICC module (only required for Marconi LH systems with more than fiveSTM-1/OC-3 lines) TRX unit (Transceiver)BPSTMNTRX STM-1SOH RPS EOW ICCFig. 1-27 Software modulesSoftware packagesThe individual software parts of each module/sub-system are combined to asoftware package or system release. 38. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200938 (125)UpgradeUpgrading the system software currently in use is a procedure taking place intwo steps: Software download Software activationDownloadThe software of a system release/software package is downloaded to thenetwork element via the DCN. Additionally, verification takes place to ensurethat the download has been successful. Downloading a new system releasedoes not affect system operation. Downloads are performed as a backgroundprocess. Depending on the throughput/load of the DCN, the download timeexpected is shorter than 2 hours. A system release downloaded must beexplicitly activated via the Network Management System (NMS). An automaticreboot after the download process does not take place.ActivationThe system release downloaded must be activated by entering the appropriatecommand. A subsequent verification is used to check whether the systemrelease has been activated successfully. Switching over to a new systemrelease does not affect/interrupt traffic. Only the connection to the NetworkManagement System may be offline for a short time (typically < 2 minutes).SW capacity of network elementsA network element includes two system releases stored in the TMN module.The other modules of the network element are automatically loaded with therequired software from the TMN module. Each network element stores itscomplete module configuration in the TMN MIB database. Using theseconfiguration data, replacement modules can be configured quickly andwithout any problems. 39. Technical Product DescriptionTRXTRX10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200939 (125)1.8 Rack DesignAll system components are mounted in ETSI racks. Alternatively, installation isalso possible in 19" racks. One standard ETSI rack can accommodate up toten RF channels with power supply modules, two fully equipped basebandunits, ten TRX units and the RF channel branching network (CBN). Theexamples below show some configurations and how the modules areaccommodated in the racks.Note: STM-1 is used to denote both STM-1 and OC-3, and MSP is used todenote both MSP and APS, in the images in this section.Power BoxBBURX-MainTXRX-DivMain antennaDiv. antennaFig. 1-28 1+1 HSB / space diversity 40. Technical Product DescriptionTRXTRXTRXTRXTRX10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200940 (125)Power BoxBBURX-MainTXRX-DivMain antennaDiv. antennaFig. 1-29 4+1 or 5+0 configuration / radio terminal 41. Technical Product DescriptionTRXTRXTRXTRXTRXTRXTRXTRXTRXPower BoxPower BoxBBURX-DivRX-MainTX10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200941 (125)TRXBBUTXRX-MainRX-DivMain antennaDiv. antennaFig. 1-30 10+0 / 9+1 terminal 42. Technical Product DescriptionTRXTRXTRXTRXTRXTRXTRXTRXTRXPower BoxPower BoxBBURX-DivRX-MainTXTRXTRXTRXTRXTRXTRXTRXTRXTRXPower BoxPower BoxBBURX-DivRX-MainTXServicechannels10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200942 (125)TRXBBUTXRX-MainRX-DivMain antennaDiv. antennaTRXBBUTXRX-MainRX-DivMain antennaDiv. antennaSTM-1channelsFig. 1-31 10+0 / 9+1 repeater 43. Technical Product DescriptionPower Box10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200943 (125)2 System Components / Sub-Systems2.1 OverviewThe Marconi LH comprises several sub-systems which are housed in one orseveral racks. A typical configuration is shown in Fig. 2-1. Up to 10 TRX units,an RF channel branching network (CBN) and up to two baseband units (BBU)with modules and auxiliary devices can be mounted in a single rack. Thefollowing sections provide a detailed overview of the functionality of theindividual sub-systems and system components.TRX UnitTRX UnitTRX UnitTRX UnitTRX UnitTRX UnitTRX UnitTRX UnitTRX UnitTRX UnitCBNfeeder linksto / from antenna(s)RackBBU shelfBBUBBU-TRX interconnectionPower BoxPower BoxmodulesFig. 2-1 System components / sub-systems 44. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200944 (125)Baseband Unit (BBU)The BBU provides the following inputs/outputs and functions: interfaces for electrical/optical STM-1/OC-3 data streams protection switching of STM-1/OC-3 data streams insertion and extraction of service channels, EOW channels, waysidetraffic, DCN channels, control information such as ATPC control signal performance monitoringIn addition, the BBU provides the following interfaces: baseband interface(s) for connecting TRX units LAN interface port for a data communication network (DCN) for O&M functions interface to a local maintenance terminal (LMT) for system configuration,software download, troubleshooting etc. port for connecting a TMN radio protection switching (RPS) functionalityThe BBU is composed of several modules interconnected via a commonbackplane.The BBU only handles STM-1/OC-3 data signals and is therefore independentof the frequency bands of the radio system.BBU shelfThe BBU shelf is used as housing for the BBU and its modules.Transceiver (TRX unit)The transceiver (TRX unit) covers the following functions: error correction encoding, modulation (128-QAM, 64-QAM), adaptivelinearization of the Tx signal, amplification of the Tx signal level, main and diversity receiver, 45. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200945 (125) adaptive equalization with space diversity combining, error correctiondecoding.In addition, the TRX unit supports XPIC operation in the CCDP mode.The TRX unit operates frequency-independently within a frequency band.Depending on the frequency band used, the TRX unit transmits/receives128-QAM or 64-QAM signals.Channel branching network (CBN)The channel branching network (CBN) performs the multiplexing of the RFtransmit channels and demultiplexing of the RF receive channels. It iscomposed of RF channel filters which allow a so-called contiguousmultiplexing/demultiplexing of adjacent RF channels.CablingThe RF ports (TX output, RX input) of the TRX unit are used to connect theappropriate channel branching filters via semi-rigid or semi-flexible(handformable) cables. Exchange of data, control signals and maintenancesignals between the BBU and the corresponding TRX unit(s) as well as DCpowering are accomplished using a single multi-wire cable.Power boxA power box provides the DC power supply required for the baseband units(BBU).OMS Multiplexer (Optional)An OMS multiplexer can be optionally mounted in the 19" rack. Thismultiplexer supports Ethernet interfaces such as 10/100BaseT or 1000BaseTand Time Division Multiplex(ing) interfaces. 46. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200946 (125)2.2 BBUDepending on the system configuration and degree of expansion, theBaseband Unit is mounted in one or several subracks (BBU shelves) whichcan be cascaded for system-internal signaling and exchange of protectionswitching signals. Each subrack can be flexibly equipped with modules andpermits transmission of up to five bidirectional STM-1/OC-3 signals. Servicechannels as well as a voice channel are provided optionally.The following modules can be mounted in a subrack: 5 x STM-1/OC-3 modules (channel-specific STM-1/OC-3 processing andSTM-1/OC-3 protection switching), 2 x BPS modules (BBU power supply, redundant in case of both BPSmodules mounted), 1 x SOH module (ECC and service channel processing), 1 x EOW module (utilization of the E1 bytes in the SOH for voicetransmission), 1 x RPS module (protection switching functions for line and equipmentprotection, not for n+0 configurations), 1 x TMN module (Network Management connection via the F- and Q-interfaceas well as EDI contacts) or1 x ICC module (necessary for internal communication if a TMN module isnot mounted).Note: STM-1 is used to denote both STM-1 and OC-3, and MSP is used todenote both MSP and APS, in the images in this section. 47. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200947 (125)Fig. 2-2 BBU architectureThe transmission capacity can be easily increased by mounting additionalSTM-1/OC-3 modules or cascading further subracks. All modules can beinserted and extracted without affecting STM-1/OC-3 transmission.The electrical/optical STM-1/OC-3 interfaces and the F-interface are locatedon the front side of the STM-1/OC-3 module or TMN module. All other externalinterfaces are arranged on the connecting panel located in the upper part ofthe subrack.2.2.1 STM-1/OC-3 moduleThe STM-1/OC-3 module performs the complete SDH/SONET processing forboth directions of a radio channel and provides a line interface for the STM-1/OC-3 signal. In addition, this module covers central protection switchingfunctions.Each STM-1/OC-3 module supports all operating modes of the system withoutany restrictions. The settings required for redundancy configurations aresoftware settings made via the local Operator Terminal PC. 48. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200948 (125)SPIel. / opt.RST LineRPSRST RadioprotectedSOHRST RadioTRX InterfaceSTM-1 moduleSTM-1line interfaceel. / opt.STM-1 internalfrom/toRPS moduleSTM-1internalfrom/toTRX UnitSOHFig. 2-3 STM-1/OC-3 moduleThis block diagram shows the signal flow in the STM-1/OC-3 module.In the "RST Line" and "RST Radio" blocks (RST Regenerator SectionTermination), a complete processing of the regenerator section in the SOHtakes place in compliance with ITU-T G.783 for both the line side and radioside. If necessary, the STM-1/OC-3 multiframe (SOH) received is passed onto the SOH module and the outgoing multiframe is overwritten by informationsupplied by the SOH module. In addition, a performance evaluation takesplace acc. to ITU-T G.826 and G.828. In line protection or equipmentprotection configurations, the radio-side receive signal available behind theprotection switching block is additionally taken into account.The line-side interface (SPI Synchronous Port Interface) is implemented asplug-in SFP module (SFP Small Form-factor Pluggable) accessible from thefront and available either as electrical or optical variant.In case of protection channels without OT function, the SFP module is notmounted. On the transmit side, the RPS (RPS Radio Protection Switching)block branches the STM-1/OC-3 signal from the line interface in the radiodirection both to the TRX interface and in the RPS module direction. On thereceive side, hitless switchover between the signals from the TRX interfaceand RPS module is possible by means of a synchronous switch.The exchange of STM-1/OC-3 signals in the TX and RX direction and internalsignaling data between the STM-1/OC-3 module and TRX unit takes place viathe TRX interface. STM-1/OC-3 signals are transmitted as digital data andclock signals via highly stable LVDS interfaces.In case of redundant system configurations, the mostly software-controlledprotection switching function of the system is distributed over the total numberof STM-1/OC-3 modules available, the STM-1/OC-3 module of the protectionchannel being treated as central module. For velocity reasons, communication 49. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200949 (125)required between STM-1/OC-3 modules takes place via a separate CAN bus(CAN Controlled Area Network) independent of network managementsignaling.2.2.2 BPS moduleIn the BPS module, the primary voltage applied via the connecting panel isconverted to the secondary voltages required by the BBU modules.A single BPS module can supply all modules available in a subrack. If asecond BPS module is provided, both modules are operating parallelly andare supplying the modules in common.In case of a failure of one BPS module, the second one immediately assumesthe entire supply of all modules without any transmission interruptions. Thesame applies to the extraction of one of the two BPS modules. In this case,however, the primary voltage of the corresponding module must first beswitched off at the fuse panel.2.2.3 SOH moduleThe SOH module is necessary if a network management system shall beconnected via the ECC (ECC Embedded Communication Channel) or if theuse of service channels is required.The ECC channels DCCr or DCCm (DCC Data Communication Channel,DCCr DCC in the RSOH, DCCm DCC in the MSOH) can be used onlyinternally via the TMN module. The following service channels are available: E1 line side (64 kbit/s, synchronous, ITU-T G.703) F1 line side (64 kbit/s, synchronous, ITU-T G.703) E1 radio side (64 kbit/s, synchronous, ITU-T G.703) F1 radio side (64 kbit/s, synchronous, ITU-T G.703) DSC1-4 radio side (4x64 kbit/s, plesiochronous, ITU-T G.703) Wayside channel WSC, radio side, (1x2Mbit/s or 2x2Mbit/s for ETSI and1x1.544 Mbit/s or 2x1.544 Mbit/s for ANSI)When using the EOW option (EOW Engineering Order Wire), the E1 byte(radio and/or line side) is automatically occupied internally by the EOWmodule and is no longer available as service channel. 50. Technical Product DescriptionF1D310/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200950 (125)The service channels E1, F1 and DSC1-4 are transmitted within the RSOH(RSOH Regenerator Section Overhead) of a STM-1/OC-3 signal. Thewayside channel occupies both free RSOH bytes and free MSOH bytes(MSOH Multiplex Section Overhead). The B2 bytes available in the MSOHare adapted on the TX side in such a way that the performance monitoringresults will not be falsified on the RX side. Fig. 2-4 shows the utilization of theSTM-1/OC-3 signal SOH.A1 A1 A1 A2 A2 A2 J0B1 RF1RF2D1 RF3 RF4 D2E2PointerB2 B2 B2 K1 K2D4D5D7D8D10D11D6D9D12E1S1 M1RSOHMSOHFig. 2-4 Utilization of the STM-1/OC-3 signal SOHStandardized bytesProcessingA1, A2 Synchronization (A1: 11110110;A2: 00101000)processedB1, B2 Performance processed *)J0 Regenerator Section Trace (Path ID) or C1 byte processedD1 - D3 Data Communication Channel (DCCR); RSOH processedD4 - D12 Data Communication Channel (DCCM); MSOH processedE1 Regenerator EOW processedE2 Multiplex EOW passed throughF1 Data Channel processedK1, K2 Bytes for Multiplex Section Protection (MSP)/Automatic Protection Switching (APS)passed throughS1 Timing Marker passed throughM1 Multiplex Section Remote Error Indication (MS-REI)passed throughMedia-specific bytesProcessingRF1,RF2RF3,RF4used for ATPC information, RPS information,radio hop ID, pol. ID, further control informationprocessed 51. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200951 (125)Standardized bytesOptional service channels(freely configurable bytes with B2 correction in the MSOH)Processing2112 kbit/s wayside channel(2048 kbit/s or 1544 kbit/s acc. to ITU-T G.703)processed288 kbit/s service channel(4x64 kbit/s, codirectional acc. to ITU-T G.703)processedTable 2-1 Utilization of RSOH and MSOH bytes*) B2 byte correction takes place if MSOH bytes are used (e.g. waysidechannel).If required, the SOH module can be mounted in each subrack. Servicechannels are always transmitted via the first STM-1/OC-3 module of thesubrack equipped with the SOH module. Depending on the service channelprotection configured, the second STM-1/OC-3 module is used in parallel.In system configurations with at least two operating channels, the line-sideservice channels can be protection-switched on the RX side. However,switchover is not hitless. This also applies to radio-side service channels, thelatter being also protected via the STM-1/OC-3 protection switching option inline or equipment protection configurations. In system configurations with atleast two operating channels, two separate wayside channels can be used. Inline protection configurations, these are individually protected via the STM-1/OC-3 protection switching option. 52. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200952 (125)WSC #1WSC #2DSC1DSC2DSC3DSC4SOH LineSOH LineSOH RadioSOH RadioFig. 2-5 Service channel modules and interfaces 53. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200953 (125)2.2.4 EOW moduleIn conjunction with the SOH module, the EOW module permits the E1 bytes ofthe SOH to be used for voice transmission in the "STM-1/OC-3 line" and"STM-1/OC-3 radio direction. As third direction, an external EOW network canbe connected either via a digital interface (64 kbit/s) or an analog 4-wireinterface. The analog interface can also be used for interconnecting analogand digital service channel networks. Furthermore a PABX can be connectedvia an analog 2-wire line.Fig. 2-6 Example of an EOW networkA handset connectable to the connecting panel permits the following functionswithin the EOW network: Selective call Group call Collective call Test tone generation 54. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200954 (125)If required, an EOW module can be mounted in each subrack.2.2.5 RPS moduleFor line protection and equipment protection configurations, a RPS module ismandatory in each subrack. It ensures the correct switching of signal pathsbetween the operating channels and protection channel and triggers the TX-sideRF switch in equipment protection configurations.On the TX side, the traffic signals of all operating channels are branched in therespective STM-1/OC-3 modules and passed on parallelly to the TRX unitsand RPS module available in the same subrack. Using the control signalssupplied by the STM-1/OC-3 modules, the RPS module decides as to whichtraffic signal will be applied to the TX-side protection switching input of theprotection channel.On the RX side, the receive signal is branched in the STM-1/OC-3 module ofthe protection channel and parallelly passed on to the line interface and RPSmodule in the subrack of the protection channel. Using the control signalssupplied by the STM-1/OC-3 modules, the RPS module decides as to whichoperating channel available at the protection switching input of the associatedSTM-1/OC-3 module the traffic signal of the protection channel will be applied.Up to an expansion of 4+1, the protection switching signals are exchangedexclusively via the subrack backplane. With higher degrees of expansion, anadditional signal exchange is required between the two subracks. For thispurpose, the RPS module is provided with an expansion input and outputlocated in the form of coaxial sockets on the connecting panel. At thesesockets, the protection switching signals are available as CMI-encoded signals(CMI Code Mark Inversion). By overlaying the CMI output signal with a DCvoltage, an expansion input is activated by the other RPS module.Three different RPS module types are available:1. RPS module HSB (05HAT00084AAK)- only for hot standby configurations2. RPS module 4+1 (05HAT00084ABC)- for n+1 up to 4+1 configurations- for 2 (N+1) up to 2 x (4+1) for CCDP configurations3. RPS module N+1 (05HAT00084ACU)- for N+1 up to 9+1 configurations- for 2 (N+1) up to 2 x (9+1) for CCDP configurations 55. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200955 (125)Note: To ensure compatibility with the MDRS 155 E system, both the connectingpanel and RPS module are provided with two inputs and outputs for protectionswitching expansions. An existing MDRS 155 E microwave radio terminaloperated in a n+1 or n+2 system configuration can thus be expanded by up toten operating channels of the Marconi LH system, the full protection switchingfunctionality being guaranteed also for expanded channels.2.2.6 TMN moduleThe main tasks of the TMN module include the connection of Marconi LHmicrowave radio terminals or repeater stations to a Network ManagementSystem and the provision of a local port for connecting an Operator TerminalPC. In addition, it provides EDI contacts (EDI External Device Interface),i.e. eight signalling inputs and four signalling outputs that can be monitoredand configured via the Network Management System.The TMN module can serve a microwave radio repeater with a maximumexpansion of 2x(9+1). The internal communication with the individual modulestakes place within the Baseband Unit via the LON protocol (LON LocalOperating Network). The TRX units are connected via the Ethernet.The Q-interface for network management connection is designed as LAN port(10 Mbit/s Ethernet, RJ-45) and located on the connecting panel. Anotherconnector is available for the QD2 station bus (RS-485) and can be software-configuredfor operation as QD2 Master or QD2 Slave.In conjunction with the SOH module, further network elements can beconnected to the Network Management System via the ECC in the "STM-1/OC-3 radio and "STM-1/OC-3 line" direction. For this purpose, either theDCCr (192 kbit/s) or DCCm (576 kbit/s) can be used.The F-interface (RS-232 via RJ-45) for connecting the local Operator TerminalPC is located on the front side of the module.The connecting panel also provides several EDI contacts (5 Volt TTL).2.2.7 ICC moduleAll subracks without a TMN module mounted must be equipped with an ICCmodule occupying the corresponding card slot. The ICC module only providesa hub functionality for the system-internal Ethernet connection between thecentral TMN module and TRX units. 56. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200956 (125)2.2.8 MSP/APS moduleThis module is used for baseband protection switching (1+1 MSP/APS andEQP) to increase operational reliability of the Marconi LH system. 1+1MSP/APS is used to protect the line side against signal errors and EQP incase of a failure of a module or functions of the STM-1/MSP or OC-3/APSmodule.2.3 TRX UnitThe TRX unit (transmitter) converts the STM-1/OC-3 data to the RF transmitsignal sent out via the antenna. At the same time the TRX unit (receiver)receives an RF signal from the antenna. The receive signal is down-converted.With digital signal processing, the STM-1/OC-3 data stream isrecovered from the receive signal. Afterwards the STM-1/OC-3 signal is sentvia the TRX-BBU interface to the appropriate STM-1/OC-3 modules of theBBU.The signal processing functionality of the TRX unit is implemented by severalcomponents/modules. Several external interfaces provide access to basebanddata signals, maintenance information and status signals.Fig. 2-7 shows the modules and interfaces of the TRX unit.Thanks to the TX and RX synthesizers used, the TRX unit can be operatedfrequency-dependently. Depending on the frequency band/channel spacing,either 128-QAM or 64-QAM is used as modulation mode. 57. Technical Product DescriptionTX/RX synthesizerTX-/RX signal conditioningTX/RX signal processing(filtering, linearizationequalization, error correction )10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200957 (125)Fig. 2-7 Modules and interfaces of the TRX unitModules of the TRX unit TRX mainboard IF module RF moduleStatus LEDs RSLFAN UnitFANinterfaceBackplane (BPL)TRX Mainboard IF module RF moduleSignal switching+System controllerRF processingTX signalReceiverMain/Diversity(RF processing)XPIC interfaceRF TX-RX interfaceTX/RXlinkIF processingTX signalReceiverMain/Diversity(IF processing)BBU-TRX interfaceTRX UnitPSUPSIindependent of frequency band and modulation modedepending on modulation methoddepending on frequency band 58. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200958 (125) Backplane FAN unitExternal interfaces BBU-TRX interface RF TX-/RX interface XPIC interface RSL interface Status LEDs FAN interfaceThe following sections provide a more detailed description of the modules andinterfaces outlined above.TRX mainboardThe TRX mainboard performs STM-1/OC-3 signal processing in both thetransmit and receive direction.TX signal processing (upstream) includes an error correction coding, digitalfiltering and digital, adaptive linearization.The analog receive signals are converted to digital signals using A/Dconverters (ADC). These are used to recover the STM-1/OC-3 signal(downstream). Receive signal processing covers the digital sampling rateconversion, adaptive slope equalization, adaptive channel equalizationincluding cross-polar interference cancellation and space diversity combiningas well as an error correction. TX and RX signal processing takes place in twoASICs.IF moduleAnalog TX signal components provided by the TRX mainboard are furtherprocessed by the IF module. This module also executes the further processingof the received and preprocessed RX signals of the RF module. This involvessignal processing steps such as down-conversion and filtering. Furthermorethe TX/RX synthesizer sub-module is part of the IF module.RF moduleQuadrature signal components of the TX signals are directly up-converted tothe TX RF frequency. The high power amplifier (HPA) provides the requiredTX output power. For the receive signal(s), this module implements a low-noisedown-converter (LNC) low noise amplifier (LNA) + down-converter. 59. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200959 (125)BackplaneThe backplane interconnects the TRX mainboard, IF module, RF module andfan unit. In addition, the power supply module is part of the backplane.FAN unitThe FAN unit is attached to the housing of the TRX unit. Two independentfans are controlled via a FAN interface.BBU-TRX interfaceSignals from/to the BBU are exchanged via this interface. The connection isset up by means of a multi-wire cable.RF-TX/RX interfaceThe RF transmit signal and RF receive signals (main/diversity) are transportedvia this interface.XPIC interfaceIn the CCDP mode, the XPIC partners exchange their receive signals at the IFlevel to compensate the effect of cross-polar coupling.RSL interfaceTwo voltages proportional to the Rx levels of the main and diversity receiverare available at the RSL interface.Status LEDsThree LEDs display general status information: Power supply BAT Operation OP Fan unit FANFAN interfacePowering of the two fans and alarm status information exchange concerningfan operation take place via this interface. 60. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200960 (125)2.3.1 Mechanical design of the TRX unitFig. 2-8 shows the mechanical design of the TRX unit.Fig. 2-8 Transceiver (TRX Unit)2.3.2 Signal processing in the TRX unit Bidirectional exchange of STM-1/OC-3 data signals Bidirectional bus signals: CAN, Ethernet Bidirectional exchange of BBU/TRX status information Exchange of signal quality indicators BBU Bidirectional exchange of ATPC information BBU TRX: requested TX level TRX BBU: receive signal level (RSL) 61. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200961 (125)2.3.2.1 TX signal processing (TX signal processing)The STM-1/OC-3 data stream is transmitted as an LVDS signal by theappropriate STM-1/OC-3 module of the BBU. Use of LVDS signalling ensuresthe integrity of the STM-1/OC-3 data signal.Signal conditioningFor digital signal processing, LVDS signals are converted to CMOS signals inthe transmit direction.In the receive direction, the CMOS signals are converted to LVDS signals.Connection matrixAfter LVDS/CMOS conversion, the STM-1/OC-3 data are applied to aconnection matrix. The default behavior of this signal processing functionconsists in passing through incoming signals (see Fig. 2-9). For testing andmaintenance purposes, the connection matrix can be configured to providevarious signal loopbacks (see Fig. 2-10 and Fig. 2-11).connection matrixFig. 2-9 Connection matrix / pass-through modeconnection matrixFig. 2-10 Connection Matrix / loopback to BBU 62. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200962 (125)connection matrixFig. 2-11 Connection matrix / loopback to transmitterMulti-level encoderThe TX data signal is applied to the multi-level encoder. The latter providesthe redundancy required for error correction. The encoded data are 128 QAMor 64 QAM encoded depending the modulation mode selected.Programmable TX filterThis 60-tap programmable digital TX filter shapes the spectrum of the transmitsignal.Digital adaptiver linearizer (DAL)Due to the non-linear distortion of the high power amplifier (HPA) integrated inthe transmitter, the transmit signal is predistorted by a digital adaptivelinearizer. Adaptive control of the DAL is achieved by comparing a "back-channel"signal with the original signal prior to predistortion. Basically, the"back-channel" signal represents a copy of the non-linearly distorted RFtransmit signal applied again to the digital adaptive linearizer. The comparisonbetween the undistorted transmit signal and the non-linearly distorted "back-channel"signal is repeated at regular intervals. Accordingly, the DAL settingsare updated at intervals of about 1 ms.Frequency offsetIf necessary, a programmable frequency offset fTX1 can be provided for thepredistorted baseband I/Q signal components. Using this frequency offset, theRF TX channel frequency of the transmit signal can be controlled veryaccurately. 63. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200963 (125)Direct QAM modulationThe I/Q quadrature signals of the predistorted transmit signal are converted toanalog signals. The analog I/Q quadrature signals trigger a QAM modulatorwhich converts the transmit signal directly to the configured TX channelfrequency. In contrast to many other state-of-the-art transceiver designs,additional signal processing does not take place at the IF level. The use of adirect modulation allows a very compact design of the transceiver.RTPC & ATPCA programmable attenuator and a variable gain amplifier provide the RTPCand ATPC functionality required for adjusting the RF output power of the TXsignal.HPA (High Power Amplifier)The RF high power amplifier (HPA) amplifies the transmit signal to the powerlevel either controlled by the ATPC or configured by the user. The non-lineardistortion of the predistorted input signal of the HPA and non-linear distortioncaused by the amplifier ideally compensate each other leading to a transmitsignal with only negligible residual harmonic distortion.Back channelPart of the transmit signal is down-converted to an intermediate frequency (IF)of 115.5 MHz. This back-channel signal is applied to the digital adaptivelinearizer (DAL).TX-RX link / RF loopTo facilitate local testing of the Marconi LH, the TRX unit offers the possibilityof switching an RF loop. If such a loop has been configured, part of the TXsignal will be looped back to the RF input of the main/diversity receiver.2.3.2.2 RX signal processingMain/diversity receiverThe TRX unit comprises a complete diversity receiver frontend for the mainand diversity signal. 64. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200964 (125)Main and diversity signals are received via two low-noise down-converters.The 1st IF frequency used by the diversity receiver is 1400 MHz. The signalsare prefiltered, amplified and down-converted to a lower 2nd IF frequency of140 MHz. Then the signal levels are adjusted again and residual interferencesignals are eliminated by means of a further filtering process.The main and diversity signals are down-converted to an IF frequency of140 MHz.If the Marconi LH operates in the CCDP mode, a copy of the main anddiversity signal must be sent to the other TRX unit which processes the cross-polarsignal. This signal will be referred to as XPIC signal in the following.XPIC signals between cross-polar TRX units are exchanged via the XPICinterface.A/D conversionThe main and diversity signals as well as the XPIC signal are converted todigital signals directly using their 2nd IF frequency of 140 MHz IF sampling.Since due to the direct sampling of the receive signals using the 2nd IFfrequency QAM demodulators are not required, the design of the TRX unit isvery compact.Programmable RX filtersThree 48-tap programmable digital RX filters provide the spectral shapingfunction for the main/diversity/XPIC signals received.ATDE, SD combiner, XPICAdaptive time domain equalization (ATDE), space diversity combining andcross-polar interference cancellation (XPIC) are carried out by three adaptivefilters each having 22 taps and a 1-tap decision feedback filter. The processedsignals are used to recover the QAM symbols.Multi-level decoderThe multi-level decoder performs the error correction.Signal conditioningThe received STM-1/OC-3 data stream is converted into a LVDS signal fordata transfer to the BBU. 65. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200965 (125)2.3.2.3 Processor conceptThe TRX unit comprises two processors CPU1 and CPU2.CPU1CPU1 uses Embedded Linux as operating system. This processor fulfills thefollowing tasks: communication with the TMN module of the BBUs configuration and supervision of the TRX unit operation and maintenance software download communication with CPU2CPU2CPU2 supports a variety of operations for time critical tasks such as adaptive TX power control (ATPC) control of AGC loop for the back-channel control of AGC loop for the main and diversity receiver calculation of the ATPC control information to be sent to the far-end TRXunitThe processor concept of the TRX unit supports two software versions.Changeover between these software versions is possible without affecting oreven interrupting signal transmission.2.3.2.4 SynthesizerThe synthesizer module of the TRX unit comprises three synthesizersproviding the LO signals required for: direct up-conversion of the TX baseband I/Q signals to the radio frequencyof the TX channel down-conversion of the TX back-channel signal to an IF frequency of115.5 MHz down-conversion of the RX signals to their 1st and 2nd IF frequency 66. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200966 (125)All three synthesizers are frequency-independent in a frequency band. Thesettings are made via an internal bus.2.3.2.5 BackplaneThe backplane interconnects the TRX mainboard, IF/synthesizer module andRF module of the TRX unit. Moreover, the DC/DC converter (power supplyunit) of the TRX unit is located on the backplane.2.3.3 FAN unitThe fan unit comprises two fans. Powering and fan status monitoring takesplace via the fan interface. The fan unit is mounted to the housing of the TRXunit. If one of the two fans fails, the TRX unit still operates within the specifiedlimits.2.3.4 External interfacesThe TRX unit provides the following external interfaces: BBU-RX RSL XPIC RF TX-RX Status LEDs2.3.4.1 BBU-TRX interface (rack interface)A multi-wire cable is used to connect the TRX unit to the appropriate port onthe BBU connecting panel. The corresponding connector is located on the rearside of the TRX unit.2.3.4.2 Power supply interfaceThe DC power supply cable is connected to the rear side of the TRX unitmounting kit. 67. Technical Product DescriptionTRX(2)-TRX(1) signallingTRX(1)-TRX(2) signallingReference oscillator10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200967 (125)2.3.4.3 RSL interfaceThe receiver input levels PRX_RX, PRX_RXD available at the RX (main) andRXD (diversity) input ports of the TRX unit are converted to analog voltagesRSL_RX and RSL_RXD. These voltages can be used either for monitoringpurposes (recording statistical data based on the Rx levels of the main anddiversity signals) or to facilitate antenna alignment. The relation between theinput power levels and voltages is linear.2.3.4.4 XPIC interfaceThe XPIC interface permits a bidirectional signal exchange between cross-polarTRX units using the same channel frequency (CCDP operation).Each TRX unit transmits and receives three signals to/from the other TRX unit(XPIC partner). These signals have different frequencies. Signaling information- Status information is exchanged via the baseband channel; Reference oscillator signal- one TRX unit is configured as master, the other as slave. The referenceoscillator of the slave TRX unit is synchronized to the reference oscillatorof the master TRX unit. Received QAM signal at 140 MHzto TRX Unit (2) from TRX Unit (2)QAM signal TRX Unit (1)at 140 MHzReference oscillatorQAM signal TRX Unit (2)at 140 MHzCoaxial cableXPIC interfaceTRX(1)Fig. 2-12 Signal exchange via the XPIC interface 68. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200968 (125)FrequencyQAM signalReference oscillatorSignallingFig. 2-13 Signals for frequency allocationSignal exchange between TRX units takes place via separate coaxial cablesfor each direction of transmission. Each TRX unit has an input and an outputconnector.The maximum length of the two coaxial cables used to interconnect two cross-polarTRX units is limited to 6 m.Cable length for one 19" rack: 2 mCable length for linking two 19" racks: 6 m 69. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200969 (125)2.3.4.5 RF TX-RX interface (RF ports)The TRX unit provides one RF output and two RF inputs for the main/diversitysignal. The connections between these RF ports and the channel branchingnetwork (CBN) are set up using semi-rigid or semi-flexible (handformable)cables.RF port Properties Label / SymbolTX RF outputSMA, femaleconnector50 Ohms TX1RX RF input connector(main)SMA, female50 Ohms RXRXD RF input connector(diversity)SMA, female50 Ohms RXDTable 2-2 RF ports2.3.4.6 Status LEDsThree LEDs on the front panel of the TRX unit provide information on theoperating status of the TRX unit.LED Status Meaning Label /Symbolgreen DC voltage (primary voltage) of TRX isLED1 within specified threshold values. off DC voltage failed or is out of thespecified range.BATred Faulty operational status of TRXred flashing Manual configuration or active testconfiguration (loopback active,transmitter off, CW transmit signal, onlyMain or only Div. in diversity operation)green TRX active, no faultLED2off TRX not activeOPoff Both fans are operating.LED3 red flashing One fan has failed.red Both fans have failed.FANTable 2-3 Status LEDs 70. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200970 (125)2.3.5 Signal processing features2.3.5.1 Digital adaptive linearization of the TX high-power amplifierThe signal to be transmitted is generated in the TRX unit by means of a digitaladaptive linearizer (DAL). Previously, its function has been provided by ananalog predistorter.Disadvantages of an analog predistortion: Analog predistorters can only be used effectively up to a non-lineardistortion of the 3rd order. When the ATPC function is active, the non-linear distortions of thepower amplifier are permanently changing. For this reason, it is difficultto find criteria appropriate to exactly deduce the settings of thepredistorter. In case of fading conditions changing quickly, the predistorteradaptation is too slow.Advantages of the digital adaptive linearizer: The digital baseband quadrature components of the Tx signal arepredistorted directly. The direct modulation permits a compact TRX design. The non-linear residual distortion is negligible. The comparison between signals takes place at digital level and thuspermits a fast detection of modulation errors such as- Quadrature phase errors- I/Q gain unbalance- LO through-connection- Non-linear 2nd order distortionThe I/Q components of the transmit signals are modified so that these errorsare compensated. Thus, testing and calibration work for the analog RF TXhardware can be minimized.The digital predistorter is updated at regular intervals of about 1 ms. This fastupdate rate permits an optimum linearity of the transmitter even in case ofperformance fluctuations of 60 dB/s. 71. Technical Product Description0-60 -40 -20 0 20 40 60-10-20-30-40-50> 20 dB10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200971 (125)The Tx signal spectrum depicted below shows the excellent features of digitaladaptive linearization. A linearization gain exceeding 20 dB is typical for thisapplication.TX signal spectrum-60(f-fc)/MHz(S-S0)/dBno adaptive linearisationadaptive linearisationFig. 2-14 TX spectrum2.3.6 Space diversity receptionPoint-to-point systems mostly use diversity techniques on the receive side. Inthis case, the Tx radio signal is sent out via a single antenna. On the receiveside, the transmitted signal is received by two antennas vertically separated. 72. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200972 (125)Fig. 2-15 Antenna configuration for RX diversityThe vertical separation D of the RX antennas depends on the hop length andterrain located between the transmit and receive antenna. The arrangement ofthe Rx antennas results in two transmission paths with channel properties(attenuation, fading etc.) more or less independent of each other. The tworeceive signals are referred to as main signal and diversity signal. Thereceiver processes these signals and combines them to one signal from whichthe transmitted data stream will be recovered. This procedure of combiningthe main and diversity signal is referred to as "space diversity combining".Generally, main and diversity signals have different delays TMain and TDivcaused by the different lengths of the signal paths. Prior to combining thesignals, this delay difference between the main signal and diversity signalmust be compensated.The TRX unit comprises a digital diversity combiner. During startup of the TRXunit, the differential delay between the main signal and diversity signal ismeasured and compensated by programmable FIFO buffers. Differential delaycompensation is an entirely automated procedure.Delay differences of up to 160 ns (equivalent to a 40 m waveguide section)can be compensated. 73. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200973 (125)Due to this sophisticated preprocessing of the main and diversity signal, thediversity combiner offers excellent features compared to classical methodssuch as IF combining using maximum power, maximum ratio or minimumdistortion criteria; Baseband switching selecting the better of the two input signals.2.3.6.1 TX-RX frequency settingsTXThe RF TX channel frequency is adjusted in two steps: Coarse frequency adjustment using the TX synthesizer with a step size offstep = 10 MHz. Fine frequency adjustment using a digital frequency offset fTX1 with a stepsize of about 1 Hz.RXThe main/diversity receiver of the TRX unit operates with two intermediatefrequencies of 1400 MHz and 140 MHz, see diagram below. The two-stepdown-conversion permits an effective suppression of spurious signals(interference signals, adjacent channel).The LO frequencies required for down-conversion are supplied by twosynthesizers. The LO signal responsible for the first down-conversion uses thecoarse frequency adjustment with a step size of about 10 MHz. Down-conversionto the second intermediate frequency takes place using an LOsignal with a considerably smaller step size of about 0.5 MHz. Any residualfrequency deviation is eliminated by the digital signal processing. 74. Technical Product Description10 MHz0.5 MHz10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200974 (125)The tuning range of the TX/RX synthesizers in conjunction with digitalfrequency settings with small step sizes permits operation of the TRX unit inthe full radio frequency band and the implementation of non-standardizedchannel patterns and duplex spacings.LowestRF RX channelHighestRF RX channelIF1 : 1400 MHzIF2 : 140 MHz0.5 MHzBB : 0 MHz1st down-conversion2nd down-conversionDigital basebandprocessingFig. 2-16 Frequency settings of Rx signals 75. Technical Product Description10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200975 (125)2.4 Channel Branching Network (CBN)The channel branching network (CBN) comprises a TX channel branchingnetwork and an RX channel branching network interconnected by a circulator.Each channel branching network has RF channel filters connected to abranching circulator. Both the TX and RX channel branching networks areterminated by means of an absorber at one end. A common harmonic rejectfilter in the TX channel branching network limits undesired emissions of higherharmonics (2nd and 3rd order). An example of a channel branching networkwith six TX/RX channels is shown in the diagram below.In case of a space diversity system, another channel branching network forthe RX diversity channels is required.The antenna waveguide is connected via a flexible coaxial cable withwaveguide transition (flange) and air outlet to the RF connecting unit.It is possible to connect diplexer filters to the circulators of the branching unit.The use of multiple diplexer filters permits a low-loss branching network to beset up. 76. Technical Product DescriptionC B N T XA 'A 'A 'A 'A 'A 'AAAAA10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200976 (125)C B Nt o / f r o m M a in a n te n n aC H 1C H 2C H 3C H 4C H 5C H 6C H 6C H 5C H 4C H 3C H 2C H 1h a rm o n i c r e j e c t f i l t e rC B N R XC '/CAFig. 2-17 Channel branching network with six TX and six RX channels 77. Technical Product DescriptionADADADADAD10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200977 (125)from DiversityAntennaCH6CH5CH4CH3CH2CH1CBN RX-DivCBN DiversityCDADFig. 2-18 RX channel branching network for diversity 78. Technical Product DescriptionHarmonic reject filter10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200978 (125)CH1CH3CH2CH4to/fromMain AntennaC'/CDiplexerCH4CH2CH3CH1CBN TXCBN RXPol. 1Pol. 21 2 3 4Fig. 2-19 4-channel branching network with diplexer filters 79. Technical Product DescriptionFlexible coaxial cables withplugs for connecting the filter tothe waveguide.CirculatorDiplexerMounting bracket forfixing the filter group ordiplexer to the CBNbracket.Tx Rx RxDiversitySMA socket AbsorberIsolator10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200979 (125)Fig. 2-20 4-channel TX CBN with two diplexers 80. Technical Product DescriptionRL > 23dB10/1551-HRA 901 16 Uen Rev B 2009-09-07 Ericsson AB 200980 (125)2.5 Antennas and Waveguid