OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Optical Master Unit Product Description and User’s Manual for Axell OMU Unit THIS DOCUMENT IS VALID FOR ALL OMU MODELS OMU is available in a range of models corresponding to repeater products
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Copyright © 2011 Axell Wireless Ltd All rights reserved. No part of this document may be copied, distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language without the prior written permission of Axell Wireless Ltd. The manufacturer has made every effort to ensure that the instructions contained in this document are adequate and free of errors and omissions.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL About This Manual This Product Manual provides the following information: • Description of the OMU Unit • Procedures for setup, configuration and checking the proper operation of the unit • Maintenance and troubleshooting procedures For whom it is Intended This Product Manual is intended for experienced technicians and engineers.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Safety to Personnel Before installing or replacing any of the equipment, the entire manual should be read and understood. The user needs to supply the appropriate AC or DC power to the OMU System. Incorrect power settings can damage the OMU System and may cause injury to the user. Throughout this manual, there are "Caution" warnings.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Electrostatic Sensitivity Observe electrostatic precautionary procedures. Caution ESD = Electrostatic Discharge Sensitive Device Semiconductor transmitters and receivers provide highly reliable performance when operated in conformity with their intended design. However, a semiconductor may be damaged by an electrostatic charge inadvertently imposed by careless handling.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Table of Contents 1 Introduction ................................................................................................................. 1 1.1 Features ................................................................................................................................ 1 1.2 Models and Ordering Information ...................................................................................... 2 1.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.10.1 OMU Signal Tapped at BTS .................................................................................... 41 3.10.2 OMU Signal Source provided by Repeater ............................................................. 42 3.10.3 Changing UL Combiner and DL Splitter Connections ............................................. 42 4 Troubleshooting .................................................................................................
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1 Introduction The Axell Wireless OMU is a scalable, RF to optic signal conversion unit. The unit is installed near the Base Station and is used in combination with fibre fed repeaters to provide wireless coverage for remote sites located at a distance of up to 20Km (12.42 miles) from the Base Station.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL • Easily replaceable modules • Simple, local setup via RS232 connection • Remote management via Ethernet connection or via modem • Various types of modems are supported: for example GSM, GSM-R, HSDPA/UMTS, TETRA, GPRS and PSTN. • Single modem (installed at the Master OMU) is required for management of cascaded OMUs • Modem can be integrated (part of the Control module) or connected separately 1.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1.3.2 Cascading OMUs Up to four OMUs can be cascaded and operate up to 24 repeaters as one system: one Master OMU and three Slave OMUs. This type of topology requires only one Control module and one modem (at the Master OMU). All OMUs and hosted Repeaters are managed as a single system via the Master OMU. BTS OMU Units Repeaters Figure 3. Four OMUs cascaded in one system 1.3.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1.4 OMU Modules The OMU is a rack type casing designed for a 19” sub-rack. The chassis supports up to six F/O to RF converters, in addition to Control, Power, Modem and additional required interface units. Each of the modules is described in detail in the following sections.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Label Unit Description Provides communications link between the Control Module and the Fiber Optic Converters. Also used when cascading OMUs. Allocated Slots 13 12 6. Rack communication board 7. Power Supply modules (A and B) PS B is optional for redundancy 8. Modem Antenna connections This module is optional. This is used 14 for OMUs with wireless modems installed that need a separate antenna.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1.4.1.1 UL Combiner and DL Splitter1 These modules perform the following functions: • Combine and distribute the RF signals between the OMU’s RF port and the Fiber Optic • Contain attenuators used to set the master signal levels in the downlink and uplink. Note: By default, the module ports are interconnected *UL In to RF out) to allow RF connections at the rear of the unit.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1.4.3 External Alarm and Battery Module The External Alarm and Battery Module performs the following functions: • Contains the rechargeable battery pack – allows the modem to transmit an alarm in case input power loss is detected. Switch for ON/OFF. • Supports connections for four external alarms and one alarm relay • The relay can be configured to trigger on any number of internal and external alarms.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1.4.5 Modem Antenna This module performs the following functions: • Relevant only if a wireless modem is installed in the OMU • Provides the connection to an external (modem) antenna 1.4.6 Modem ANT To external antenna Rack Communication Board This module performs the following functions: • PWR Provides communications link between the Control Module and the Fiber Optic Converters within the rack.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 1.5 Rear Panel Note: The rear-panel layout can vary depending on the configuration. The rear panel provides the following functions: • Power - Plinths for power connections – requires opening the rear panel. • GND - screw for earthing • RF input - N-connector for RF input. There is one connector if the Rx/Tx input is combined and two connections if the Rx and Tx are to be fed separately.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 2 Installation 2.1 Unpacking Unpack the OMU Inspect the shipped material before unpacking the equipment, document any visual damage and report according to routines. A delivery of an OMU from Axell Wireless contains: Checklist with delivered items OMU CD containing RMC and User’s Manual Any other specifically ordered item 2.2 Mounting in Rack The OMU is designed to be mounted in a 19” sub rack.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 2.4 Connections 2.4.1 RF Connections The modules can to be configured in two ways as shown in the illustration below. UL in DL out UL in DL out RF out RF in RF out RF in Alternative 1 In Alternative 1 the connectors on each module are linked and the input to the OMU is made via the Nconnectors on the back of the OMU. See also illustration below.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL The configuration at delivery is Alternative 1. Connect the OMU to the BTS or to the repeater. Attach the coupler The connector for the uplink and the downlink connector are N-type and placed on the OMU rear panel. The OMU is connected to the BTS (or the repeater) via a directional coupler (illustrated below). The coupler is connected in series with the BTS antenna (see 2.4.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL block light. Fortunately, it is very easy to clean the connector. Be sure to use the correct procedure for the given connector. When disconnected, cap the SC/APC connector to keep it clean and prevent scratching the tip of the ferrule. Alternative 1 Swipe the tip of the ferule 2-3 times with a cotton swab soaked in alcohol. Let it air dry. Alternative 2 Use a product specially designed for the purpose. 2.4.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL The relay can be configured to trigger on any number of internal and external alarms. The maximum current through the relay is 100mA.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Either a separate antenna is connected to the modem antenna port, or the connection is be made via a coupler connected to the RF input to the OMU. The latter alternative can only be used if the OMU runs on the same frequency as the wireless modem and is equipped with a duplex filter. 2.4.5.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL The OMU and the wireless modem operate on different bands (for example an OMU for TETRA with a GSM modem) In this case the OMU will have one port where an external antenna can be connected. To external The connector is SMA type. Modem ANT antenna 2.5 Connecting Power and Power-up Caution! Make sure the antenna cables or 50 ohm terminations are connected to the OMU’s antenna connectors before the OMU is switched on.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL PWR In OK Out OK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Battery on/off Battery Power On Off Power switch On Off Caution! Even if the power supplies are switched off the OMU still has live power from the power input on the back. Check Control Module LEDs © Axell Wireless Ltd Refer to 4.1.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 2.6 OMU Module Configuration Examples An OMU can be configured in many different ways. These are two examples.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Example 2 In the example below there are separate inputs for Rx and Tx and no duplex filter. An external modem antenna is connected and linked to the modem on the Control Module.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3 Setup 3.1 Initiate Local Communication 3.1.1 RMC Communication Connect to the LMT port Connect the computer to the LMT port on the Control Module via a DB9 male connector with serial RS232 interface.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.2 Configure the OMU 3.2.1 Set OMU Name (TAG) The TAG can be chosen freely to give the OMU a name that is linked to the location, the site name, etc. The TAG may contain up to 30 characters including spaces. Select “Configuration” and “Product” Insert the OMU’s name (TAG) in this box. Note! The ID should not be assigned from here. The AEM will do this automatically when the repeater is integrated in the system. 3.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL of 20 km. For each connection in the link (for instance at the ODF) approximately 0.5 dB of loss will have to be added. The loss compensation function is activated as the system is set up. Please see section 3.5 Set Up OMU-Repeater System. Each time the system has been changed or fibres have been exchanged or moved for some reason, it is recommended to re-activate this function.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.3.1.1.2 Re la y The External Alarm and Battery Module contains a relay output. The relay can be used to indicate a summary status of the repeater. Each alarm source can be configured to be affecting the relay or not. Note! The relay status is never affected by the login / logout alarm parameters. For installation testing purposes, it is possible to test the open / close function of the relay.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Fill in the information for each repeater in the pop up window. Serial number The serial number consists of 4 letter and/or digits. It is printed on the yellow label on the repeater Bus number When OMUs are cascaded they run on different buses. OMU 1 and OMU 3 is on “bus “0 and OMU 2 and OMU 4 in on” bus 1”..
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Select HUB Status Check the levels of the received optical signals via the RMC 3.6 Balance the System To estimate the signal levels in the system, a link budget should be prepared before the system is made operational. This section provides background on calculating the required attenuation values along the link and describes how to set the attenuation value in the management application. 3.6.1.1.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL The following diagram illustrates the attenuation levels for an installation with a common Tx and Rx port.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.6.1.1.2 Fib e r Lo s s Co m pe n s a tio n Activate the fibre loss compensation in both the downlink (from the OMU) and in the uplink (from the repeaters) paths. See 3.7 Initiate Fiber Loss Compensation. 3.6.1.1.3 Up lin k P a th The uplink gain setting of the OMU and connected repeaters affects the sensitivity in the connected BTS sector and the connected repeater cells.
AXELL OPTICAL MASTER UNIT Go through all racks and all fibre optic converters one by one and initiate the compensation process PRODUCT DESCRIPTION AND USER’S MANUAL First chose the rack and then the fibre optic converter. In an OMU that contains only one sub rack – this rack is called “Rack 1” Additional sub-racks/slave OMUs that are linked to the master OMU are named “Rack 2, 3 and 4”. Each fibre optic converter is numbered from left to right in each sub-rack.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Note! Earlier repeater versions If the OMU is connected to repeaters of an earlier release, which has a fibre optic converter of the type in the photograph, these commands will not work. Instead a default value needs to be defined by using the command OLC. Please see OMU Command and Attributes for more detailed information regarding this command. The OLC value should be set to 6dB.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.8.1 Communication via Modem The Control Module is responsible for enabling the power to the modem, unlocking the SIM-card, using the configured PIN-code and making sure the modem is logged in to the network correctly. Depending on network configuration and modem usage, the modem might require different modem initialization strings to work properly. This modem initialization string is set and verified during repeater setup. 3.8.1.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.8.2.1 Modem Configuration, not using GPRS Select “Configuration” and “Communication” Select Data Call Initialization string Connect times AEM addressed are set via the AEM 2004-01-01 Select Data Call Set the modem initialization string. This string differs between networks. Primary recommendation is AT+CBST=71,0,1;\Q3. If remote communication cannot be established try 7,0,1 or 0,0,1 or 7,0,3.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Select GPRS Initialization string Connect times AEM addressed are set via the AEM Configure GPRS Select GPRS Set the modem initialization string. This string differs between networks. Primary recommendation is AT+CBST=71,0,1;\Q3 Tick “Enable Automatic Modem Power Cycling” for the modem to be power cycled once every 24 hours. Set the time at which the modem should be tested.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Wait for the modem to restart. This can take a few minutes. When the modem settings are ready the LED turn green. 3.8.2.3 AEM Addresses The Control Module can be configured with two different addresses (telephone numbers) to which alarms and reports are delivered. In case the repeater cannot deliver alarms and reports to the primary address, the next call will be made to the secondary address.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.8.2.5 SIM-card Using Single Numbering Scheme If the network is configured using Single Numbering Scheme (SNS), some special considerations apply. The repeaters are by default configured so that networks using SNS always will have calls routed to the data service in the modem.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Select “Configuration” and “Communication” Set IP address and other relevant information here In these screens the Ethernet and/or DNS Gateway parameters can be set 3.8.5 Troubleshooting Remote Communication Since many networks have their own “personality”, performing first time configuration of the remote communication sometimes requires tweaking of the modem parameters.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL This illustration is a simplified schematic of the remote communication between a GSM module in an OMU and an analogue modem. The analogue modem in the computer communicates with the Interworking Function Unit (IFU), which is the GSM network analogue network interface. The call is routed via the switch centre over the air interface to the data call number in the SIM-card of the GSM module.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL AT&W Saves the current modem configuration into NVRAM. This means that this configuration will be used directly after modem power up AT&F Loads the modem factory configuration ATZ Resets the modem, and loads the default settings as saved with command AT&W 3.8.5.2 Trace Modem For troubleshooting purposes it is possible to trace the actual progress of initializing the modem.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL or NO CARRIER will be displayed almost immediately. Try to change the modem initialization string. The modem initialization string mainly used to configure the remote communication is AT+CBST. Successful modem initialization strings used by Axell Wireless includes (most common first): AT+CBST=71,0,1;\Q3 AT+CBST=7,0,1;\Q3 AT+CBST=0,0,1;\Q3 AT+CBST=0,0,1;\Q3 AT+CBST=7,0,3;\Q3 Once the modem initialization string is entered, try again to dial u
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL In order to have good signal quality, Axell Wireless recommends that the signal strength should be better than -95 dBm. If signal strength is lower, try to adjust the antennas to get a better signal strength from the donor. Documentation of +CSQ command from a modem’s manual. In the example the reply to AT+CSQ is 0,7 meaning 7*2 dB above -113 dBm; the modem detects a signal level of -99 dBm.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL In order to change the modem string, go to the OMU command prompt. Try changing the modem initialization string and log out to let the controller reinitialize the modem. If problem remains, try a few different modem initialization strings. Axell Wireless has been successful with the following modem initialization strings: AT+CBST=71,0,1;\Q3 AT+CBST=7,0,1;\Q3 AT+CBST=0,0,1;\Q3 AT+CBST=0,0,1;\Q3 AT+CBST=7,0,3;\Q3 Please refer to the modem manua
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.10 Installation Examples 3.10.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 3.10.2 OMU Signal Source provided by Repeater Server Antenna Donor Antenna ODF ODF AEM Antenna or Leaky feeder Modem Coupler Fiber Fed Repeater Channel Selective Repeater Power Unit for -48 V DC optional Back-up Battery An example of a site installation where the FR signal to the OMU is tapped off a repeater 3.10.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL Fibre port UL in DL Splitter UL Combiner RF out OMU front side RF in RF out RF in DL out Optional links Fibre Optic Converter OMU back side DL UL Note! In the illustration above only one Fiber Optic Converter is shown. The other converters are connected in a corresponding way. The configuration at delivery is Alternative 1.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 4 Troubleshooting 4.1 Module LEDs 4.1.1 WDM Module LEDs On the Fiber Optic Converter module there are six LED indicators; one for power status, one for error, two for the data communication and two for the RF signals.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 4.1.2 Control Module LEDs Modem Status Modem Power Status Login The Control Module has four LEDs which give information regarding the status of the OMU. If the OMU is configured for Ethernet communication the two LEDs Modem Power and Modem Status do not fill any function and can be disregarded.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 4.1.3 GSM Modem Behavior Note! This LED behaviour is valid only for GSM modems. Other modem types will be added in later editions.
OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 5 Maintenance 5.1 General The system normally operates without any operator intervention or maintenance. Should the system malfunction, the condition of the antenna systems as well as the continuity of the cabling should be checked before replacing any of the OMU units. In the unlikely event of a unit failure, the field replaceable components (antenna unit, cables, etc.) should be checked and replaced if faulty and the system restored.
AXELL OPTICAL MASTER UNIT PRODUCT DESCRIPTION AND USER’S MANUAL 6 Specifications RF Parameters Frequency Response model dependent Gain Flatness Typical 2 (p-p) dB Nominal RF input power +10 dBm composite power Maximum RF input power +23 dBm composite power Fiber optic loss compensation Implemented Optical Modules Number of optical modules 1-6 Laser class Class 3B Wavelength 1310 ± 10 nm or 1330 ± 10 nm Optical output power +5 ± 2 dBm Maximum Optical Input Power +5 dBm Output Power (Tx)
