SRAL-XD-sys.pdf

SRAL XD Siemens Radio Access Low Capacity

SRAL XD, Siemens Radio Access Low Capacity, 17 September 2006, Issue 1 SRAL XD v2

Contents ..............................................................................................................................................4 Safety Rules

...................................................................................................................................................4 General.................................................................................................................5 Radio Frequency (RF) Safety

..................................................................................................................................6 ESDS Precautions

............................................................................................................................8 SYSTEM DESCRIPTION

....................................................................................................................................8 SRAL XD system...........................................................................................................................................8 System build

....................................................................................................................10 IDU-ODU Interconnection..................................................................................................................................14 Supporting frame

........................................................................................................................16 PHYSICAL INTERFACES

........................................................................................................................................16 Power supply..............................................................................................................................16 E1 Tributary signals

.............................................................................................................16 Wayside (wst) service channel......................................................................................................................................16 User channels

....................................................................................................................................18 External Alarms................................................................................18 Monitoring the received RF power from the ODU

..........................................................................................................................18 Supervision interfaces

...........................................................................................................................21 Functional Description

...................................................................................................................................21 IDU Architecture..........................................................................................................................21 2 Mbit/s Tributary Unit

............................................................................................................................22 Base Band (BB) Unit.......................................................................................................................................23 Controller unit

..................................................................................................................................23 IDU Composition............................................................................24 LEDs, Monitoring Points, Connectors and Switches

.................................................................................................................................26 ODU Architecture

SRAL XD, Siemens Radio Access Low Capacity, 17 September 2006, Issue 1 Page 2 of 53SRAL XD v2

Protection System Architecture ............................................................................................................30

..............................................................................................................................30 Tributary Protection........................................................................................................................31 RX Tributary Protection........................................................................................................................31 TX Tributary Protection

............................................................................................................................32 Protection Structures.....................................................................................................................32 Hardware protection logic

.........................................................................................................................34 Hitless protection logic

...................................................................................36 Service Channels Management and Protection

...................................................................................36 Radio Embedded Communication Channel (R)..............................................................................36 Tributary Embedded Communication Channel (D)

.............................................................................................................................38 External Connections

.......................................................................................................................................................38 IDU..................................................................................................................40 External interfaces (32xE1)

..........................................................................................................................41 BaseBand (BB) board

............................................................................................................42 Installation and Commissioning

.......................................................................................................................................42 Initial Settings..............................................................................................................................................42 Activation

.............................................................................................45 Normal operating conditions and Alarms

..............................................................................................................................................46 Loop Backs

.............................................................................................................................46 Tributary loop-backs

............................................................................................................................................47 Maintenance

............................................................................................................47 Troubleshooting and Restoring................................................................................................................................52 List of Spare Parts

.............................................................................................................53 Procedure for Spare Parts use


Safety Rules General

This section contains the safety rules and precautions to be followed when working on the SRAL-XD, in order to avoid injuries to personnel and/or damage to the equipment. The equipment complies with the 89/336/EEC European specification.

The equipment is designed to work with a dc supply (-48 to -60 V ± 20%); therefore follow the appropriate procedures for low voltage equipment.

Electrical safety

Warnings for electrical safety

The equipment complies with the EN 60950-1 safety specifications.

The equipment must be installed, started up, managed, and repaired only by properly trained personnel.

Before powering up the equipment, it is necessary to complete the wiring of the connections to the protection ground, the insertion of all the units and/or modules provided for the requested configuration and also the connection of all the necessary connectors.

The connection to the protection ground must not be removed or damaged.

External operations

During the installation and start-up phase other dangerous situations could arise during, for example, the erection of the Outdoor Unit (ODU). During such operations, it is necessary to strictly follow the safety rules listed below:

During installation, while the antenna and/or the external supporting-frame are lifted, it is strictly forbidden to stand or pass in the underlying area. Such an area must be properly restricted or signed.

For the external operations to be executed on the antenna, on the frame and on the ODU, all the necessary safety rules against accidental fallings must be respected. For example, it is necessary to use protection fences and belts.

During the equipment starting up phase, engineers must not be in front of the antenna.

If the safety rules mentioned above are not followed, injuries to personnel may result.


Radio Frequency (RF) Safety

The RF sources used in this product are contained in the ODU. All combinations of ODU and antenna equipment supplied by Siemens fully comply with European Harmonised Directives relating to RF safety (EN 50385 published 7th December 2002).

The use of this kind of RF source requires several precautions to avoid personal injury.

The following rules must be followed:

• Remain behind an antenna which is in an unknown operational state or has it’s connected ODU(s) powered up.

• Do not move in front of or pass in front of an antenna without confirming that ODU(s) connected to the antenna are switched off.

• If the ODU(s) are not disconnected, not switched off or is in an unknown operational state do not directly stare at an open flexible waveguide or a waveguide aperture on either an antenna or ODU. Also be aware of potential RF reflections of metallic surfaces.

• Check that the associated ODU is switched off before connecting or disconnecting a waveguide or IF cable connector.

• Do not power up an ODU unit without confirming that all connections (both waveguide and IF) are terminated correctly.

• Do not use the ODU outside of it’s intended application and do not change the factory settings.


ESDS Precautions

The ESDS (Electro Static Discharge Sensitive) electronic devices can be partially or permanently damaged by the static electricity that is commonly present in the operating environment.

The main ESDS devices are:

• CMOS components

• Large Scale Integration components in MOS technology

• SAW (Surface Acoustic Wave) components

• Operational amplifiers with MOS/FET inputs

• MOS/FET components and arrays

• Microwave semiconductors and microcircuits at frequencies > 1 GHz

Modules containing ESDS devices are identified by the following adhesive label:

In order to avoid any damage while handling the modules, the user should wear an antistatic elastic bracelet, grounded by means of a spiral cord.

Those modules that are mounted on the equipment (faulty or spare parts) shall be stored in their original antistatic packaging and clearly labelled as stated above.


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SYSTEM DESCRIPTION SRAL XD system

Vodafone will use the SRAL XD system operating within the 7 to 38 GHz frequencies, utilising the plug-in Indoor unit (IDU) and providing the following traffic capacity:

• 4xE1

• 8×E1

• 16×E1

• 32xE1

System build

The diagram opposite shows the SRAL XD (16xE1 IDU) equipment block diagram. The equipment has been built by physically subdividing it into two assemblies: an outdoor unit (ODU) and an indoor unit (IDU).

This subdivision allows:

• the RF losses, due to the interconnection between the ODU and the antenna, to be minimised

• a common IDU, for all applications.

According to the configuration, one or two ODUs will be equipped.

The connection between IDU and ODU is made through a single coaxial cable.

It is possible to use antennas with different diameters depending on the hop length required.

Vodafone will use the High Density configuration (up to 32E1s), with 16 TCM modulation.


• SRAL XD equipment block diagram (16xE1)

ODU

F Interface

IDU Basic functions:

System interface to the outside worldBaseband digital signal processingIDU-ODU cable interfaceSupervision, configuration/management Power supply management

Control and supervision signals and channels

ODU Basic functions:

IDU-ODU cable interface managementModulation of baseband digital signalDemodulation of the received RF signalSupervision and configuration/managementManagement of the communication channelReceived Signal Strength Indication (RSSI)

V-LAN Interface

Q-LAN Interface

ALM Interface

E1 Interfaces

USER-1 Interface

USER-2 InterfacePS Interface

Tributary and service sig-nals (pay-load)

IDU

IDU-ODUinterconnection(coaxial cable)

IDU-CABLEinterface

ODU-CABLEinterface

RSSIinterface ANTENNA

interfaceRF

interface

Integrated antenna

ODU

F Interface

IDU Basic functions:

System interface to the outside worldBaseband digital signal processingIDU-ODU cable interfaceSupervision, configuration/management Power supply management

Control and supervision signals and channels

ODU Basic functions:

IDU-ODU cable interface managementModulation of baseband digital signalDemodulation of the received RF signalSupervision and configuration/managementManagement of the communication channelReceived Signal Strength Indication (RSSI)

V-LAN Interface

Q-LAN Interface

ALM Interface

E1 Interfaces

USER-1 Interface

USER-2 InterfacePS Interface

Tributary and service sig-nals (pay-load)

IDU

IDU-ODUinterconnection(coaxial cable)

IDU-CABLEinterface

ODU-CABLEinterface

RSSIinterface ANTENNA

interfaceRF

interface

Integrated antenna


IDU-ODU Interconnection

The interconnection between the IDU and the ODU, shown on the following diagrams, consists of a single, two-way, line transporting one composite signal comprising the 51.84 Mbit/s (16xE1) or the 155.520 Mbit/s (32xE1) IDU-ODU stream and the ODU power supply voltage.

51.84 Mbit/s signal

The signal that is received from the ODU (or from the IDU) is sent to the receive circuits via an, ‘active hybrid’.

A 128Kbit/s auxiliary channel is present on the stream connecting the IDU and the ODU. This channel transports all the data necessary for the equipment to operate properly (alarms, data channel, etc.).

ODU Power Supply

The IDU-ODU interconnection cable also transports the auxiliary DC voltage, required to power the ODU, which is supplied by the corresponding BB unit of the IDU. In this unit we also find the soft-start circuits, the current limitation circuit and the generation of the open cable alarm or short-circuited cable alarm.

The diagrams opposite show the SRAL-XD set-up in an unprotected (1+0) system with an integrated ODU (left) and an independent ODU (right). The integrated ODU option will be the preferred method.

The diagrams on page 10 show the SRAL-XD set-up in a protected (1+1) system with integrated ODUs (left) and an independent ODUs (right). The integrated ODU option will be the preferred connection method.


• 1+0 system with an integrated ODU (left) and an independent ODU (right)


• 1+1 Hot Stand-by system with integrated ODUs (left) and independent ODUs (right)




Supporting frame

1+0 supporting frame

The 1+0 supporting frame consists of a Coupler, and the relevant waveguide accessories, suitable for the mounting of the Outdoor Unit, on the mast.

From an electrical point of view the frame is a passive device (i.e. waveguide section) that provides interconnection between its two ports with negligible insertion loss.

1+1 Supporting frame for Hot stand-by with integrated antenna

The 1+1 supporting frame for Hot Stand-by again consists of a Coupler, and the relevant waveguide accessories, suitable for the mounting of the Outdoor Unit, on the mast. Vodafone will use an unbalanced coupler. The signal received from the antenna port is split, unbalanced towards the two ODUs.

1+1 Supporting frame for Hot stand-by with independent antenna

The 1+1 supporting frame for Hot Stand-by again consists of a Coupler, and the relevant waveguide accessories, suitable for the mounting of the Outdoor Unit, on the mast. This will again be an unbalanced coupler.

ODU

CouplerODU

ODU

CouplerODU


• 1+1 Supporting frame for a hot stand-by system with an integrated ODU

Frequency Frequency Insertion loss Code Coupler type Coupling (dB) Band (GHz) Range (GHz) (dB)

534-120/01 15 14.4-15.35 unbalanced < 11 < 1.3

534-120/02 18 17.7-19.7 unbalanced < 11 < 1.3

534-120/03 23 21.2-23.6 unbalanced < 11 < 1.3

534-120/04 26 24.5-26.5 unbalanced < 11 < 1.3

534-120/06 38 37.5-39.5 unbalanced < 11 < 1.5

• 1+1 Supporting frame for a hot stand-by system with an independent ODU

Frequency Frequency Insertion loss Code Coupler type Coupling (dB) Band (GHz) Range (GHz) (dB)

534-121/01 15 14.4-15.35 unbalanced < 11 < 1.5

534-121/02 18 17.7-19.7 unbalanced < 11 < 1.5

534-121/03 23 21.2-23.6 unbalanced < 11 < 1.5

534-121/04 26 24.5-26.5 unbalanced < 11 < 1.5

534-121/06 38 37.5-39.5 unbalanced < 11 < 1.7


PHYSICAL INTERFACES The diagram opposite shows the physical interfaces of an IDU.

Power supply

The IDU provides a redundant input line for the connection of the power supply batteries to the equipment.

E1 Tributary signals

The IDU provides, on the front panel of the IDU, upto 32 I/O lines for the 2 Mbit/ s tributaries, with 75 Ohm unbalanced or 120 Ohm balanced interfaces.

Wayside (wst) service channel

The IDU provides the communication for a 2 Mbit/s Wayside (WST), service channel, for user defined applications, this is not currently used by Vodafone.

User channels

The IDU also provides 64 kbit/s synchronous service channels for applications defined by the user, these are not currently used by Vodafone.

These are point-to-point channels, which are transparent to the channel contents.

The user channel configuration is controlled through software, via the Controller unit.


• IDU physical interface


External Alarms

The IDU provides an alarm interface, consisting of two main functions:

• transparent transport, through the radio link, of up to 4 alarm conditions (e.g., door alarm, smoke alarm, etc.)

• sending 7 output alarms, relevant to the equipment status.

Monitoring the received RF power from the ODU

The ODU has a monitoring point by which it is possible to measure the received radio signal.

Supervision interfaces

• The “F” interface is used to provide the “SRAL XD” with its LCT connection, which will be locally connected to the equipment, in order to perform supervision and configuration of the local node.

• The “R” interface is used to allow a “SRAL XD” to SRAL XD” connection, when the NEs are not located in the same location and are the terminals of one radio link (i.e. only a radio connection is available between the NEs). The “R” interface is internal to the equipment, and is not accessible to the user.

• The 10Mbit/s “V-LAN” Ethernet interface is used to allow “SRAL XD” to “SRAL XD” networking for supervision purposes, when the NEs are placed in the same location and they are not terminals of the same radio link (i. e. only cable connection is available among the NEs).

• The 100Mbit/s “Q-LAN” Ethernet interface is used to allow “SRAL XD” to “SRAL XD” networking for supervision purposes, when the NEs are placed in the same location and they are not terminals of the same radio link (i. e. only cable connection is available among the NEs). The “Q-LAN” and “V-LAN” interfaces permit daisy chaining for Network Management

• The “Q-LAN” interface will carry the Netviewer connection, for alarm/supervision purposes.

Examples of the above interfaces are shown in the diagram opposite.


• Network supervision




Functional Description IDU Architecture

The basic version (1+0) of the IDU consists of:

• a Tributary unit (75 Ohm unbalanced. or 120 Ohm balanced.), that represents the physical access of the equipment for the 2 Mbit/s (E1) Tributary streams

• a Controller unit that includes all the control and supervisory functions.

• a BB unit, that includes all the base band processing, cable protection and IDU-ODU auxiliary service channel management

The Tributary unit also includes all the alarm and remote commands that interface to/from the remote terminal.

The IDU provides an EEPROM memory fitted on the Controller unit and a KEY to insert onto the Tributary unit containing all the configuration parameters.

2 Mbit/s Tributary Unit

The Tributary unit consists of 2 sub-units connected together with a cable, the two units are:

• a common unit • an E1 interface unit The unit carries out the following functions:

• impedance matching of the 2 Mbit/s I/O tributaries • input tributary branching towards the two BB units should the equipment have been set to the

protected configuration.

The unit therefore consists of all the circuitry required to produce non-Hitless switching between the two aggregate signals, when the equipment has been set to the protected configuration. In this manner the BB card is protected against failure.

The front panel of the Tributary unit is provided with a power supply switch for the switching ON and OFF of the whole SRAL XD equipment.


Base Band (BB) Unit

The unit carries out the following functions:

• Regeneration of the 2 Mbit/s input tributary signals

• Monitoring of the incoming 2 Mbit/s streams

• generation of the aggregate frame and multiplexing of the input tributary signals into a 51.84 Mbit/s/155.52 Mbit/s stream

• scrambling and aggregation signal encoding

• generation of a 128Kbit/s auxiliary service channel for the transmission of data channels, alarms etc., between the IDU and the ODU, that will be inserted into the above stream

• generation of the switching command for the non hitless switch situated on the BB unit, should the equipment be set to the protected configuration.

• automatic level control on the signal received from the ODU.

The unit also comprises of:

• all the circuitry necessary to carry out the hitless switching function, between the two aggregate signals, when the equipment has been set to the protected configuration.

• all the circuitry necessary to realise the "Line driver" function in order to send and receive the following signals from the ODU via only 1 coaxial cable:

• 51.84/155.520 Mbit/s stream

• power supply voltage for the ODU

The unit also contains the DC/DC converters for its own power supply.


Controller unit

The Controller unit implements a system controller, that is capable of managing all the system configurations. The main functions are:

• collection of alarms and parameters from the system units (IDU and ODU); transmission of this information to a local PC and to the network supervision system (NetViewer)

• activation of system commands coming from the local PC or from a network supervision system (status forcing, modification of equipment parameters, etc.)

• storage on a Memory key of the system configuration and on EEPROMs the inventory / user data and alarm history.

• routing of messages between the controller and the network supervision system

• electrical and protocol translation between the radio environment (which uses a proprietary protocol channel, embedded in the radio frame, to transport management information) and the supervision system (which requires a standard protocol).

IDU Composition

The plug-in IDU consists of a wired sub-rack, where all the plug-in units are housed.

The sub-rack will be secured in a standard 19" rack.


LEDs, Monitoring Points, Connectors and Switches

The diagram opposite illustrates the front panel of the indoor assembly, showing the LEDs, monitoring points, etc. The function of the LEDs is shown below.

Unit LED Colour Meaning

General ODU alarm: lights up when an alarm is present on the ODU or the ODU Red Alarm ODU is disconnected

CABLE alarm: lights up when current drain is lower than expected. The Yellow causes might be due to the cable either breaking down or being

disconnected, or to the absence of the ODU. CBL Alarm

CABLE alarm: lights up when current drain is higher than expected. The Red cause might be due to a short-circuit on the cable or on the ODU.

Green Lights up when the Base Band signal implements its own normal path in both directions (TX and Rx) (1+1 systems). CH A1

Yellow Lights up when the channel concerned is used with software forcing.

Green Lights up when the Base Band signal implements its own normal path in both directions (TX and Rx) (1+1 Systems). CH B1

Yellow Lights up when the channel concerned is used with software forcing.

Base Band Unit

General alarm inside the unit: Card Fail alarm. It lights up also when there Δ' Red are no internal power supply voltages.

General alarm inside the unit: Card Fail alarm. It lights up also when there Δ' Red are no internal power supply voltages.

Manual operation in progress: the LED lights up when the equipment is TEST Yellow not operating according to its configuration, but is "forced" into an unusual

condition.

CRITICAL/ MAJOR Red Critical/ Major alarm: if ON it denotes the presence of a Critical/Major"

alarm inside the IDU.

Controller Unit

Minor/ Warning alarm: if ON it denotes the presence of a "Minor/Warning" MINOR/ Red WARNING alarm inside the IDU.

All the power sources of the equipment are OK (after the POWER switch Tributaries Unit PS OK/Δ' Green has been switched "on"). The LED will be 'off' when at least one power

supply. is not functioning.

Internal general alarm of the Unit: an alarm is active whose origin is internal Red to the Unit. The LED lights up in the case of a missing internal power

source.

• If the unit is not active, both LEDs (CH A and CH B) are OFF.

If the RJ45 connector of the Q-LAN and V-LAN interfaces are present then two green LEDs are available: LED1 (left front view) signals the receive status and LED2 signals the connection status, of the interface.


• IDU front panel (1+1 – 16E1) configuration

1. Main power switch 2. -48 volt input to BB1 3. -48 volt input to BB2 4. InterFace (IF) connector for Base Band (BB) Unit 1 5. InterFace (IF) connector for Base Band (BB) Unit 2 7. 2048Kbit/s connection point (tributaries 1-8) 8. 2048Kbit/s connection point (tributaries 1-8)

10. External Alarm connector

11. V11, 64Kbit/s Service Channel 1 (not used by Vodafone) 12. V11, 64Kbit/s Service Channel 2 (not used by Vodafone) 13. Connection point for the Licence Key 14. 100Mbit/s Q LAN Ethernet connection 15. 10Mbit/s V LAN Ethernet connection 16. LCT (F) interface, 9-way D-type (RS232)

18. Controller Unit LEDs

19. Base Band (BB) Unit 1 LEDs

20. Base Band (BB) Unit 2 LEDs


ODU Architecture

The functional block diagram of the ODU is shown opposite.

BB-I (Base-Band and Cable Interface) Section

The BB-I section is in charge of the following tasks:

• IDU-ODU cable base-band interface management

• ODU power supply interface management

• IDU-ODU management signals

Power Supply Section

The Power Supply section is in charge of the following tasks:

• ODUs interface to the external power supply (from the ODU-CABLE interface)

• The equipment's internal power lines, and power distribution to third level power supply sources.

• Detection and management of alarms related to the equipment's power supply system.

Modem Section

In the modem section there is a modulator capable of performing the required modulation.

The ODU HD/HP uses 4 QAM modulation in HP mode and 16 TCM modulation in HD mode.

Controller Section

The Controller section is in charge of the following tasks:

• Monitoring of the ODU alarms and configuration.

• The ODU interface to the IDU controller.


• ODUs functional block diagram

ODUCONTROLLER

Section

PowerSupplySection

Base-Bandand cableInterface

(BB-I)Section

MODEMSection

IntermediateFrequency

(IF)Sect ion

RadioFrequency

(RF)Section

Duplexer

Signal BUSControl BUSPower supply BUS

RSSI ODU-CABLE Antenna Interface

ODU’s external interfaces


IF section

The "Intermediate Frequency" section is responsible for the following main tasks:

• up-conversion to IF (TX IF signal) of the modulated signal generated by the digital modulator, and delivery of this IF signal to the RF section;

• down-conversion to in-phase and in-quadrature components and filtering of the IF signal received from the RF section; delivery of down converted signals to the demodulator;

• monitoring of the operating conditions of the IF circuits and of the integrity of the internal interfaces, and the generation of the associated alarms.

RF Section

The "RF" section is in charge of the following main tasks:

• up-conversion to the desired RF frequency of the incoming IF (modulated) signal, output of the "IF" section;

• low-noise reception of the RF signal from the far end radio transmitter;

• down-conversion to the desired IF frequency of the received RF signal from the far end radio transmitter.

ODU Identification

The ODU comprises a hermetic container, arranged for pole fixing, inside which RF modules (depending of the operating range), Modem and power supply modules (common in all RF ranges) are housed.

Adjustment and composition of the ODU RF units depend on the working RF frequency range.

The ODU versions likely to be used within the Vodafone network are all of the ‘High Density (HD) type. As can be seen below, a different ODU will be required for each different frequency band:

• P/N 732-241/15 : 15 GHz version • P/N 732-241/18 : 18 GHz version • P/N 732-241/23 : 23 GHz version • P/N 732-241/26 : 26 GHz version • P/N 732-241/38 : 38 GHz version


• “Vertical” polarization application (ODU “High Density” - HD)

• “Rx field measure” connector


Protection System Architecture The system protection in the 1+1 configuration can be split in two functional blocks:

• tributary section • service channels section

Tributary Protection

• Hardware protection: this performs the system protection from hardware failures (e.g. failure of electronic devices). This mode can't avoid “burst errors”, because it is a hardware switch as a result of alarms due to failures that, in the time preceding the switch, allowed the equipment to operate in a degraded condition (LOS, LOF etc.)

• Hitless protection: this performs system protection from selective and temporary link quality degradation e.g. the propagation fadings. This mode, based on memory buffers that guarantee the bit to bit alignment, can operate an error free protection when fading is less than 100 dB/sec

The protection modes of the SRAL XD system follow the following rules:

• Each HW failure occuring in the TX path (IDU to ODU) is protected by activating the available ‘hardware switches’, as per the Hot Standby mode

• Each HW failure occuring in the RX path (ODU to IDU), is protected by activating the “hitless switch” (in this case the “hitless switch” works like a hardware switch i.e. it does not perform “error free protection”)

• Each HW failure occuring in the RX path of the IDU, is protected by activating the available “hardware switches"

Note that when the protection system activates the ‘hardware switches’, both the paths, TX (IDU to ODU) and RX (ODU to IDU), are switched at the same time in the following Cases:

• any failure of the active transmission path tream to the “hitless switch” • failure of the active RX path downs

• ‘CARD FAIL’ of the active BB unit

LINK ID CODE error, detected via software, on the active BB unit

uces the amount of tributary traffic lost in the opposite direction, to that where the RX failure happened.

• Removal of the active BB unit • The operating mode of the protection system minimises the number of TX hardware switches. In the case of RX path failure of the active ODU, this red


RX Tributary Protection

• the RX switches, inside the Common Access unit, are controlled by a command which is sent from the protection logic.

The hitless switches receive the tributaries at both inputs. The switching is operated by logic circuitry, described later. It is based on the detected alarms: the hitless switches protect against alarms from the RF section and the other sub-units; the final switches only protect against hardware failures.

TX Tributary Protection

Vodafone have chosen to use the 1+1 Hot Standby configuration for their TX tributary protection

Note: The following symbols are used:

• PRF: RF power value of the signal outgoing from antenna; • P1: power value set via SW for the main ODU; • P2: power value set via SW for the secondary ODU; • Pmin, Pmax: Minimum and maximum allowed power values.

1+1 Hot-Standby configuration without RF switches (one antenna).

In this configuration the secondary ODU is coupled with the main ODU via a coupler (CL). The direct unit has priority and it will be used when no alarms exist (revertive mode). It is possible to use the unrevertive mode (configuration option).

The main ODU can be squelched if hardware failure conditions occur in the TX path. The squelch commands are controlled via SW depending on the status of the command generated by the TX protection logic, but can also be locally generated in the ODU, if the communication channel between the IDU and ODU is not working.

The controller manages the TX Power value of the main and standby channels in order to guarantee a (C/I)min.

In Hot-Standby (1+1) configuration, when an alarm occurs the system switches from the main unit to the stand-by. Before switching the power transmitter fail alarm (TX_PWR_ALM) is latched. Two cases are possible:

1. If the TX_PWR_ALM is active then the system behaves in the unrevertive mode, that is: the secondary unit keeps on working until the operator forces the main unit back into service.

2. If the active alarm is not TX_PWR_ALM, the secondary unit keeps on working until the alarms on the main unit have cleared. The system automatically switches back to the main unit


Protection Structures

The various protection architectures are shown in the diagrams opposite.

The switching commands shown in the above mentioned figures are generated by the protection logic, this is implemented on both BB units. This logic uses the following inputs:

• alarms and status signals coming from the radio units.

• configuration set by the local operator interface (PC) or by the remote management system.

The operation of the switch, activated via software, allows the the active radio channel, at the receiver side, to be switched regardless of the status of alarms and external commands. This switch overrides the hitless protection logic.

When the power supply of a card containing a switch fails, the switch automatically goes in a disabled status, in order to avoid interference with the signal passing through the other way.

Hardware protection logic

This logic protects the system from hardware failures of IDUs and ODUs.

The hardware protection logic allows the transmission to the antenna of the signal coming from the unit with no alarm (TX side protection) and the transmission to public connectors of the tributary coming from the unit with no alarm (RX side protection).

The hardware protection logic, split in TX section and in RX section, generates the following commands:

• HW SW CMD that controls TX and RX switches at the same time;

• RF SW CMD in case of Hot Standby configuration.

In Hot-Standby configuration, the switch command is generated on both the BB units and sent to the corresponding ODU, through the communication channel between the IDU and ODU, managed by the BB unit.

In all cases, when the communication channel is not working or is disconnected, the corresponding ODU guarantees an open switch to avoid unwanted conditions. The open switch status is automatically maintained during power up.


• TX protection in Hot-Standby configuration with one antenna

• RX Protection


Hitless protection logic

This logic protects the system from link quality degradation.

The hitless protection logic generates a software command, in addition to the alarms of the local radio channel and the remote radio channel, that the hitless protection logic, on both the BB units, receives as inputs.

The diagram opposite shows where the alarms, used by the logic and listed below, arise.

• Loc ODU Alm a failure alarm coming from the corresponding ODU. This alarm is sent through the communication channel between the IDU and ODU and managed by the switching logic housed in the local BB unit.

• Loc DEM Alm a failure alarm coming from the local IF-DEM section. This alarm is sent through the communication channel between the IDU and ODU and managed by the switching logic housed in the local BB unit.

• Loc HL Alm a failure alarm coming from the local RX hitless section.

• Loc H-EW a High Early Warning alarm coming from the local FEC.

• Loc L-EW a Low Early Warning alarm coming from the local FEC.

• Rem HIGH Alm a failure alarm coming from the remote system. This alarm is the sum of the remote ODU, DEM and HL alarms.

• Rem H-EW a High Early Warning alarm coming from the remote FEC.

• Rem L-EW a Low Early Warning alarm coming from the remote FEC.


• Alarms of Hitless protection logic


Service Channels Management and Protection The radio service channels used within the Vodafone network are:

• R 64 kbit/s synchronous contra-directional embedded channel, reserved to transmit radio network supervision messages.

• D 64 kbit/s, synchronous contra-directional channel, reserved to transmit radio supervision messages, using a time slot of the 2Mbit/s tributary. The channel is managed through the Controller unit, in mixed radio/cable links.

• Dext 64 kbit/s, V.11, synchronous contra-directional channel, managed by the Controller unit, an alternative to the 2Mbit/s embedded D channel, it connects other NEs (e.g. SRA 4) to the network management center.

Service channels are identified as ‘Services Insert’ and ‘Services Drop’. In (1+1) Hot-Standby configurations, the same tributary is transmitted on both aggregated radio channels. Service channel protection thus follows the same rule as the tributary.

Radio Embedded Communication Channel (R)

The R channels are managed throughout the Services Drop/Insert functional blocks of the Base Band unit and are directly connected to the Controller unit.

In the 1+1 configuration, the status of software commands determine which of the two channels is active, whereas the CONFIG signal, set by the local operator, carries the active channel towards the SCC1 port of the Controller unit.

Tributary Embedded Communication Channel (D)

The D channels are connected to the Controller via the access unit. In the 1+1 configuration, the status of the commands determines which of the two channels is active, whereas the CONFIG signal, set by the local operator, carries the active channel towards the HDLC1 port of the Controller unit. In this case the second HDLC port of the Controller is available for the Dext channel.

In the other configurations, the CONFIG signal enables the passage of both channels to the relevant HDLC ports of the Controller unit. If the embedded D channels are disabled, for example, via remote management, the HDLC ports are available for two Dext channels.




External Connections All the connectors used for external connections are easily accessible from the front of the indoor unit.

IDU

Primary supply voltage connection

The outdoor assembly (ODU) is remotely power supplied by the IDU, by means of 1 coaxial connection cable (2 in the 1+1 configuration).

The indoor assembly BB units are fed by DC/DC converters, which transform the delivered -48 V voltage.

• Alarm connections

Pin Alarm Description 1 ALIM OFF No power supply alarm

9 TEST Abnormal condition (i.e. Tributary loop active)

2 IDU IDU alarm

10 MINOR OR WARNING “Minor” or “Warning” alarm

3 CRITICAL “Critical” alarm

11 ODU ODU alarm

4 MAJOR “Major” alarm

12 CEN-OUT2 Station alarm output #2 (from remote station)




14 CEN-IN2 Station alarm input #2 (to remote station)




•


• Supervision connections (Q LAN - V LAN)


External interfaces (32xE1)

Using the same SRAL XD IDU architecture, SRAL XD can support 32xE1 tributary interfaces using a new access board, and a new BaseBand board. Interfaces associated to the Controller board are identical to the previous versions.

• 32xE1 external tributary interfaces these carry 32xE1 tributary signals. The required impedance is both 120 ohm and 75 ohm, the connection is via four mini RJ21 connectors. The different impedances are provided via different cabling on the same connector. Each E1 uses six pins (three for TX and 3 for RX).

• Parallel Alarm interface: this is associated with alarm collection, including remote and local status information. An Open/Ground logic is used. The connector is a 15 way D- type.

• D ext/User interface (2x): up to 2 interfaces can be used to carry user information towards the radio link (User interface) or to carry supervision messages towards a V.11 interface (D ext).

• Memory key: this interface is used for memory key insertion.

• Power supply switch: a locking lever switch is installed to switch on/off the radio unit power supply.

• LED: one LED is available on the access board, to detect the board status.


BaseBand (BB) board

• Power supply interface: the connector type is a 3-way D-type. A - 48 V input power supply is required.

• IDU-ODU interface: this is the interface between the IDU and ODU, through a single coaxial cable. It carries the following logical signals: Radio frame (i.e. the aggregate frame which carries multiplexed signals which must be transported by the radio link), ODU control channel (which is the channel used for IDU-ODU communication), ODU Power supply, hardware commands and alarms (i.e. some hardware commands and alarms are available for functions which require communication between IDU and ODU).

• LEDs: five LEDs are available on the BB board, these detect system status. LED management is the same as the SRAL XD family

• The 32xE1 Indoor Unit


Installation and Commissioning Initial Settings

In this section instructions are given to check and, if required, to carry out configuration changes.

All configuration is carried out through the LCT software.

System EEPROM

The IDU contains two different system EEPROMs to store the configuration:

• an internal EEPROM in the Controller unit

• an external EEPROM (KEY), inserted in the front panel of the Tributary unit.

Stored on the key is the Serial Number (S/N) and the licence type.

Activation

This section includes the checks that should be carried out during the installation and on the activation of the equipment.

Local checks

All units are tested and adjusted at the factory in order to optimise the characteristics: usually, checks on these units are not required once installed.

Therefore, these procedures will only be used in case of problems arising in the system, due to equipment malfunction.

The checks are:

• check the connection cables (or cable) between the indoor assembly and the outdoor assemblies (or assembly) are connected and the IDU/ODU connection has been made.

• check the equipment is connected to the primary supply voltage.


IDU first installation

• Insert the KEY into the connector on the Tributary unit.

• Switch ON the IDU by operating the switch situated on the front cover of the Tributary unit.

• At this point the Controller reads the S/N and the type of license off of the KEY and stores it internally.

• The LCT should now be able to complete the equipment configuration. (Based on the type of license memorised, a basic default configuration will be memorised on the KEY).

• When configuring the equipment through the LCT, the configuration will be automatically memorised both on the Controller unit and on the KEY.

The KEY must always be inserted during equipment configuration. Should it be removed, the "Memory key disconnected" alarm will be activated.

If a KEY other than that used during the first installation is inserted, while the equipment is ON, the Controller compares the S/N and the type of license memorised (corresponding to the first installation KEY) with that of the KEY inserted. A data misalignment is detected and the "No setting mode" alarm is activated, which will prevent modifying the configuration through the LCT.

The following are the alarms associated with the KEY:

Alarm Description LCT alarm Key missing The Key has been removed Memory key disconnected Key Fault Non recoverable data failure Key fault Key Mismatch Data memorised on the key differs from that No setting mode

memorised on the IDU

Antenna Alignment

It is necessary to execute the alignment of the antennas to ensure the correct operation of the equipment and to ensure a reliable radio link to the remote terminal.

To assist with the aiming operation, the ODU is equipped with a BNC connector that provides an AGC voltage output as a function of the received signal.

The VAGC range is between -3.4 V and 1.2 V (typical values) for PRX values between -30 dBm and -75 dBm, according to a linear law with a rate of about 0.5 V for 10 dB.


Local checks on the equipment

Control of the system configuration

Control, by means of the supplied SW (LCT), that the system configuration is as required.

Configuration of an IP address

On the first installation, the IDU has a default IP address (192.168.255.3), this allows the user to access the NE, set the network IP address and build the map containing the IP address itself.

If a network IP address is not available, it is necessary to insert, in the two terminals, addresses belonging to two different IP sub networks (for example: site A = 100.100.100.6; site B = 150.150.150.6), Net mask 255.255.255.0, will allow control of both Network Elements

Final checks

After all the local checks and the alignment operations have been executed, check that the levels of the received power in both the terminals are in compliance to the project specification.

Switching test

Where protected configurations are used, check the switching functionality.

With the aid of a PDH (2 Mbit/s) frame analyser, connected to the tributary access points, check that, after the different switching operations, the service stays active.

Restore of the operating conditions

Once the checks on the connection have been executed, restore the operating conditions of the system (removing the possible manual forcing).


Normal operating conditions and Alarms

Normal operating conditions

Normal operating conditions of the equipment are indicated as follows:

• Power Supply switch on the Tributary unit (“ON” = position “I”) • all red LEDs on the front panel of the units: OFF • RF output power and RF input power at nominal values.

The normal operating conditions of the front panel LEDs are shown on the diagram opposite.

Alarm conditions

An alarm condition indicates a failure in the outdoor or indoor unit.

An alarm condition in the equipment is indicated by the switching on of a red LED on the front panel of the failed unit.

The alarms are also processed and managed by the Controller unit. The LCT, connected to the Controller unit, allows an easy location of the failed unit.


Loop Backs The following loop-backs are provided for maintenance purposes.

Tributary loop-backs

• “Local” loop-back (A) The tributary signal can be looped back in the base-band unit at the input interface level. This type of loop-back when activated allows testing the integrity of the circuitry related to line interface access.

• “Remote” loop-back (B) Each tributary stream can be looped towards the remote station. This type of loop-back when activated allows testing connection integrity between two terminals.

Each available tributary (i.e., each enabled tributary) can be looped back either locally or remotely using suitable software commands (“test commands”), issued via LCT or Netviewer.

• Tributary loop-backs


Maintenance Troubleshooting and Restoring

This section will discuss the type of troubleshooting to be carried out on the equipment.

The malfunctions are pointed out by LEDs on the equipment, on the indoor assembly front panel.

The sequence of recommended actions to locate a faulty part of the equipment, to replace it and to restore the service, will be discussed during this section.

Troubleshooting

The failed unit is located by using the LCT.

Unit replacement procedures in 1+0 systems

This section contains the steps required to carry out faulty part replacement.

Follow the instructions step by step, or the SW configuration could be lost.

Note: The IDU front panel LEDs give general fault status information; in cases where more detailed information is required about the cause and severity of an alarm, the LCT should be used.

ODU replacement

1. Disconnect the IDU/ODU cable (ODU side).

2. Replace the ODU and connect again the IDU/ODU cable.

3. Verify that the link has recovered (no alarms)

IDU-ODU cable replacement

1. Disconnect the faulty IDU-ODU connection cable.

2. Connect a new IDU-ODU cable.

3. Verify that the LEDs on the tributary units are in their normal operating condition.


Replacement of the IDU units

Base Band Unit

1. Disconnect the power supply cable from the front panel of the unit.

2. Remove the faulty unit.

3. Insert the spare unit.

4. Connect back the power supply cable on the front panel of the unit.

5. Check that the link has been restored (no alarms).

Controller unit

1. Remove the unit (the NE will be lost from LCT).

2. Insert the spare Controller unit. The equipment configuration, that has been memorised on the KEY, will be automatically stored in the new Controller unit.

Tributary unit

1. Disconnect all the cables from the front panel of the unit.

2. Switch OFF the unit through the switch on the front panel of the unit.

3. Remove the unit.

4. Extract the KEY.

5. Insert the KEY in the spare unit.

6. Insert the spare unit in the sub rack.

7. Re-connect the cables.

8. Switch on the unit through the switch placed on the front panel of the unit.

9. Check that the link has been restored (no alarms).


Unit replacement procedures in 1+1 systems

This section contains instructions to carry out unit/parts replacement.

Follow the instructions step by step, or the SW configuration could be lost.

Note: The IDU front panel LEDs give general fault status information; in cases where more detailed information is required about the cause and severity of an alarm, the LCT should be used.

ODU replacement

1. Force ON LINE the other BB unit and the hitless switch via LCT commands.

2. Using the LCT, power down the ODU to be replaced.

3. Disconnect the IDU/ODU cable (ODU side).

4. Replace the ODU and re-connect the IDU/ODU cable.

5. Using the LCT, power up the replaced ODU.

6. Wait until all alarms disappear from the alarm list.

7. Wait at least 30 seconds before removing any ‘forcing’ LCT commands.

8. Verify that the link has recovered (no alarms).

IDU-ODU cable replacement

1. Force ON LINE the other BB unit and the hitless switch via LCT commands

2. Using the LCT, power down the relevant ODU.

3. Disconnect the faulty IDU-ODU connection cable.

4. Connect a new IDU-ODU cable.

5. Using the LCT, power up the relevant ODU.



8. Verify that the link has recovered (no alarms).


Replacement of the IDU units

Base Band Unit

1. Force ON LINE the other BB unit and the hitless switch via LCT commands.

2. Using the LCT, power down the relevant ODU.

3. Disconnect the power supply and IDU/ODU cables from the front panel of the unit.

4. Remove the faulty unit.

5. Insert the spare unit.

6. Re-connect the power supply cable on the front panel of the unit.

7. Wait until the BB unit goes ‘on line’.

8. Using the LCT, power down the relevant ODU line.

9. Re-connect the IDU/ODU cable on the front panel of the unit.

10. Using the LCT, power up the relevant ODU.



Controller unit

1. Remove the unit (the NE will be lost from LCT).

2. Insert the spare Controller unit. The equipment configuration, that has been memorised on the KEY, will be automatically stored in the new Controller unit.


Tributary unit

1. Disconnect all the cables from the front panel of the unit.

2. Switch OFF the unit through the switch placed on the front panel of the unit.

3. Remove the unit.

4. Extract the KEY.

5. Insert the KEY in the spare unit.

6. Insert the spare unit in the sub rack.

7. Re-connect all the cables.

8. Switch on the unit through the switch placed on the front panel of the unit.

9. Check that the link has recovered (no alarms).

Configuration change

1. The configuration change described in this section refers to the change of capacity in 1+1 systems.

2. Force ON LINE the BB unit and the hitless switch via the relevant LCT commands at the remote station.

3. Force ON LINE the BB unit and the hitless switch via the relevant LCT commands at the local station.

4. Change the capacity on the ODU not ON LINE at the remote station.

5. Change the capacity on the ODU not ON LINE at the local station

6. Force ON LINE the other BB unit at the remote station.

7. Force ON LINE the other BB unit at the local station.

8. Perform the same capacity change in the ODU not ON LINE at the remote station.

9. Perform the same capacity change in the ODU not ON LINE at the local station.

10. Remove any ‘forcing’ LCT commands.


List of Spare Parts

The maintenance philosophy consists of the replacement of an outdoor assembly (ODU) or a unit in the IDU.

IDU spare parts list

The example given below is for the 16xE1 IDU

Denomination Part Number (P/N)

16xE1 Tributary unit (75 ohm coax) or 612-404/37A or 16xE1 Tributary unit (75/120 Ohm D-type) 612-404/38A Controller unit (without V-Bus) 634-001/73A controller unit (with V-Bus) 634-001/74A 16xE1 Base Band unit 612-314/39A Wired sub rack 628-586/26 Cover 333-309/80

ODU spare parts list

Each ODU has been adjusted in the factory to a frequency of an RF channel. The list of the available ODUs is given in the following table.

Radio Frequency (GHz) Density ODU Part Number (P/N) 15 High 732-241/15-xxx 18 High 732-241/18-xxx 23 High 732-241/23-xxx 26 High 732-241/26-xxx 38 High 732-241/38-xxx


Procedure for Spare Parts use

This section illustrates the procedure required when replacing a faulty IDU part or a faulty ODU.

To simplify the description, the following procedures concern the disassembling of the parts, to replace, proceed in the opposite manner.

Procedure for the IDU unit replacement

The replacement of the units of the IDU assembly can be carried out in the following manner while the equipment is operating:

1. Disconnect the cables present on the front panel of the unit to replace.

2. Unscrew the screws present on the unit's front panel.

3. Remove the unit.

Procedure for the ODU replacement

To replace the ODU remove the ODU from the supporting framework, fastened to the mast.

The procedure to follow is specified below:

1. Pull out the IF cable.

2. Disconnect ground.

3. Disconnect the RF waveguide.

4. Remove the ODU from the supporting frame.


Documents

SRAL-XD-sys.pdf