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TRACER
User Manual
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User Manual
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ADTRAN TRACER User Manual

61280004L1-1A-1A PAGE I
TRACER USER’S MANUAL
PAGE II 61280004L1-1A-1A
61280004L1-1A-1A PAGE III
INSTALLATION
CONTENTS
PAGE
SECTION 1TRACER DESCRIPTION ..................................................... 1
CHANNEL SELECTION.................................................3
FORWARD ERROR CORRECTION ....................................4
E1 OPERATION .......................................................4
TRACER SYSTEM CONFIGURATION ..................................6
Baseband Processor or BBP........................................ 6
VT-100 RS-232 Interface ............................................. 8
Alarm Contacts ............................................................. 8
IF Signal ....................................................................... 8
AC/DC Power................................................................ 9
Controls and Indicators ............................................... 9
Radio Frequency Convertor or RFC ........................... 11
Antenna Selection ...................................................... 13
SECTION 2INSTALLATION ..............................................................15
UNPACK, INSPECT ........................................................15
RACK-MOUNTED RFC CONFIGURATION .........................15
MAST-MOUNTED RFC CONFIGURATION .........................15
INSTALLATION ..............................................................16
LOCATION AND MOUNTING.........................................16
POWER REQUIREMENTS ........................................... 16
GROUNDING ......................................................... 16
E1 INTERFACE ......................................................18
LINK PLANNING ...........................................................19
SETTING THE TRANSMITTER POWER ...................................22
SETTING THE RFC FREQUENCY PLAN ................................23
CONNECTING THE BBP AND THE RFC .............................. 24
APPLYING POWER ........................................................25
AUTOMATIC BBP FREQUENCY PLAN .................................. 25
PAGE IV 61280004L1-1A-1A
SPREADING CODE ........................................................25
CO-LOCATING MULTIPLE 2.4 GHZ SYSTEMS .......................25
ANTENNA ALIGNMENT .................................................... 26
RF LOW ...................................................................27
REMOTE BERT ..........................................................27
ALARM CONTACTS ........................................................27
SECTION 3OPERATION ................................................................29
VT-100 USER INTERFACE .............................................29
RS-232 INTERFACE .................................................... 29
CABLE CONNECTIONS ....................................................29
PASSWORD ................................................................30
MAIN MENU SELECTIONS ............................................... 31
SECTION 4TROUBLESHOOTING .......................................................37
GENERAL .................................................................. 37
PROBLEM DESCRIPTIONS AND RECOMMENDED ACTIONS ........... 38
TROUBLESHOOTING USING THE FRONT PANEL INDICATORS ..... 38
TROUBLESHOOTING USING THE VT-100 USER INTERFACE..44
SECTION 5SPECIFICATIONS ........................................................... 49
RF TRANSMITTER ........................................................49
RF RECEIVER............................................................. 49
FREQUENCY PLANS .......................................................49
SPREAD SPECTRUM DATA PUMP ......................................49
E1 INTERFACE SPECIFICATIONS ........................................ 50
USER INTERFACE ......................................................... 50
RS-232 TERMINAL INTERFACE........................................ 50
MECHANICAL & ENVIRONMENTAL .......................................50
POWER.....................................................................51
GLOSSARY .............................................................................55
APPENDIX ACABLE CONNECTIONS ................................................... A-1
61280004L1-1A-1A PAGE V
PAGE VI 61280004L1-1A-1A
61280004L1-1A PAGE 1
SECTION 1 TRACER DESCRIPTION
INTRODUCTION
The Single E1 version of Tracer provides single E1 transport via a
2.4 GHz, direct sequence, spread spectrum microwave link. The transmitter output power is 20 dBm maximum while the receiver sensitivity is -91 dBm or better. System performance is determined, in part, by the engineering of the microwave link. Each Tracer radio is comprised of two components - the baseband processor and the radio frequency converter (RFC). The E1 interface (G.703, G.704 compliant) is provided on the back of the baseband processor, which is mountable in a 515 mm rack. The radio frequency converter is rackmountable adjacent to the baseband processor or mastmountable in a weatherproof enclosure, located up to 110 meters apart, using RG-8 style coax. A single coaxial cable connects the baseband processor (via a Type N connector) to the RFC and another coaxial cable connects the RFC to the antenna (via a Type N connector).
PAGE 2 61280004L1-1A SECTION 1
APPLICATIONS
Any application that would typically use metallic E1 as a transport can use the Tracer instead. The figure below illustrates a typical application.
Antenna Antenna
RF Cable
Rackmount RFC
VT-100
RS-232
Terminal
E1, Mastmounted RFC
TRACER Baseband Processor
E1
E1 Equipment
IF Cable
RF Cable
TRACER Baseband Processor
E1
E1 Equipment
E1, Rackmounted RFC
Figure 1-1. Typical Application
The Tracer can be used in any application requiring that data be shared at a high rate of speed. In addition to telephony applications, Tracer can be used in data communications such as inter-networking, video conferencing, and telemetry.
SPREAD SPECTRUM
Spread spectrum is a form of communication in which the bandwidth of a message signal is intentionally increased or “spread.” There are two methods of spreading -- frequency hopping and direct sequence. Tracer employs direct sequence spread spectrum.
Rackmount RFC
61280004L1-1A PAGE 3
T
RACER DESCRIPTION
DIRECT SEQUENCE
A direct sequence transmitter spreads the signal by mixing the data with the output of a pseudorandom number generator which changes state at a rate higher than the data rate. This rate is called the “chipping” rate. The Tracer chipping rate is twelve times the data rate.
CODING
Many different pseudorandom sequences exist. The sequences are called pseudorandom because, although they appear noise­like, they are determinant and repeat after a specific number of chips. The longer a code is, the better correlation characteristics it possesses. These traits allow multiple spread spectrum systems to operate in the presence of one another with minimal interference if they are operating with different sequences. The Tracer allows the selection of one of ten different 120-bit long sequences.
CHANNEL SELECTION
There is 83.5 MHz of spectrum in the 2.4 GHz band in which Tracer operates. A Tracer system fully uses the available bandwidth
-- transmitting in one half and receiving in the other. The figure below illustrates the bandwidth division.
2400 MHz
2441 MHz
2483.5 MHz
Figure 1-2. Bandwidth Division
PAGE 4 61280004L1-1A SECTION 1
The transmitter at one end of a link will transmit in the lower half of the spectrum. Consequently the receiver at the other end will receive in the lower half of the band and transmit in the upper half. Thus, a system will operate in one of two frequency plans -
- transmit in the upper and receive in the lower or vice versa. These two plans are called Plan A and Plan B. One end of a path will be on Plan A and the other will be on Plan B. Shipment of a link will consist of an A and a B unless specified otherwise.
FORWARD ERROR CORRECTION
With the addition of overhead data, error detection and correction capability can be added to a data stream. Error correction can be accomplished by allowing the receiver to request the re­transmission of an errored block once detected. The Tracer, on the other hand, implements forward error correction (FEC) which adds enough overhead data for the receiver to detect and correct errors in the data stream. This capability comes at the cost of bandwidth. The addition of FEC decreases the required signal­to-noise (S/N) ratio by approximately 5.5␣ dB to achieve a given bit error rate (BER).
E1 INTERFACE
The E1 interface conforms to the ITU G.703 and G.704 electrical and signaling interface recommendations. Two interfacing configurations are allowed - a pair of BNC coaxial connectors or a 15 pin sub-D connector and RJ48 connector.
The coaxial connection provides a 75Ω unbalanced connection. The shield of the TX coaxial connection is attached to earth ground. A strap is provided to optionally connect the shield of the RX coaxial connection to ground as described in G.703. The 15 pin sub-D and RJ48 connection provides a 120Ω balanced connection.
61280004L1-1A PAGE 5
TRACER DESCRIPTION
Tracer SYSTEM CONFIGURATION
A Tracer system is composed of three major subsystems -- a baseband processor, a radio frequency convertor, and an antenna. The following section describes the system components.
BASEBAND PROCESSOR OR BBP
The baseband processor or BBP is a 1-U, 515 mm rackmountable unit. This unit provides the system electrical interfaces, user controls and indicators, and performs the spread spectrum processing for the system. The front panel provides all of the electrical interface points -- E1 interface, VT-100 compatible terminal, alarm contacts, IF signal, and DC power (from facility or optional AC adapter).
The BBP front and rear panels are illustrated in the figures below.
E1
ALM
TEST
LBK
CVCRC
POWER
LOS/OOF
TRACER
FREQ
SYSTEM
PLAN APLAN A
RF LOW
PLAN BPLAN B
LINK DOWNLINK DOWN
Figure 1-3. BBP
IF MAJ
E1
G.703
75 OHM
RS232
RXTX
MIN DC POWER
NOCOM NC NO COMNC
Figure 1-4. BBP Rear Panel
PAGE 6 61280004L1-1A SECTION 1
A block diagram of the BBP is shown in the figure below.
µ
Σ
Figure 1-5. BBP Block Diagram
VT-100 RS-232 INTERFACE
An RS-232 interface is provided via a 25-pin D connector for attaching a VT-100 compatible terminal. The active signals used on this interface are listed below
Signal Name Pin Number Source
Receive Data ...................2 ................ Terminal/Modem
Transmit Data .................3 ................ Tracer
Request to Send .............. 4 ................ Terminal/Modem
Clear to Send ..................5 ................ Tracer
Data Set Ready ................ 6 ................ Tracer
Signal Ground ................ 7
61280004L1-1A PAGE 7
TRACER DESCRIPTION
The management system allows the E1 interface to be provisioned. The line code can be selected as AMI or HDB3. The signaling can be selected as channel associated signaling (CAS) or common channel signaling (CCS). Alarm conditions can also be monitored. The management system will report the following alarms on the E1 interface:
• Loss of signal
• Bipolar violation
• CRC error
• Framing error
• Remote alarm
A seven-day error history of the E1 interface and radio link is also provided. Fifteen-minute histories are provided for the most recent eight hours of operation.
The status of the microwave link can also be monitored from the management system. The transmitter power setting as well as an indication of the received microwave signal level are provided.
ALARM CONTACTS
Two classes of alarm, MAJOR and MINOR, are provided. A MAJOR alarm is signaled if, for any reason, the microwave path is not operational. A MINOR alarm is signaled when the data path is operating, but impaired. A minor alarm will be activated when an alarm is sensed on the E1 interface or when the received RF signal level falls below approximately -80 dBm. Both normally-open and normally-closed contacts are provided for each alarm class. Access is provided by a six-position terminal strip on the front of the baseband processor.
IF SIGNAL
The Type N Connector provides the interface point between the baseband processor and the radio frequency converter (RFC). This connection provides the signal, power, and configuration information to the RFC. A coaxial cable (ADTRAN part number 3125RF027@A) is provided for connecting the BBP to the RFC for the rackmount model. Cable for connecting the BBP to a mastmount RFC must be provided by the customer after the length of the cable has been determined.
PAGE 8 61280004L1-1A S
ECTION 1
AC/DC POWER
The unit receives power via one of two connectors. Power for the entire system is provided by these interfaces. The 3 pin circular DIN connector is provided to connect an ADTRAN supplied desktop AC adapter providing 24 volts DC. The three-pin terminal block allows the connection of any DC power source providing between 21 and 60 volts DC. The power consumption of the entire system is approximately 30 watts.
CONTROLS AND INDICATORS
The system may be configured via the front panel, which is accessible behind a drop-down panel on the right half of the BBP. The front panel is illustrated in the figures below.
TEST
POWER
E1
CVCRC
LOS/OOF
ALM LBK
PLAN A PLAN B
FREQ
SYSTEM
RF LOW LINK DOWN
TRACER
Figure 1-6. BBP Front Panel with Door Closed
Figure 1-7. BBP Front Panel with Door Open
61280004L1-1A PAGE 9
TRACER DESCRIPTION
As a rule, a green LED indicates a good situation, a red LED indicates an error situation, and a yellow LED indicates a configuration option. LEDs indicating overall system integrity are listed below.
Self Test ........................ Blinking red if the self-test has completed
and failed; Solid red if self-test is in progress or did not complete
Power ........................... Green if DC voltage is applied
The LEDs associated with the E1 interface are listed below.
CV/CRC ....................... Red if the incoming E1 stream contains code
violations, or a CRC error
LOS/OOF ..................... Red if there is no signal present at the E1
interface or if framing synchronization is lost
Loopback ..................... Solid yellow if the E1 interface is in local
line loopback. Blinking yellow if the E1 interface is in link loopback.
ALM ............................. Solid red if an AIS is detected at the
incoming E1, blinking red if a remote alarm signal is found
The functions of the LEDs which relate system configuration information are listed below.
Frequency Plan A ........Yellow if frequency plan A is selected
Frequency Plan B ........ Yellow if frequency plan B is selected
Remote Test Active ...... Yellow if the remote test is active
Remote Test Fail .......... Red if the remote test failed
The LEDs that indicate error conditions in the spread spectrum data pump and RFC are listed below. All of these LEDs are visible through the front panel. Any one of these LEDs indicates and error condition that precludes system operation.
Link Down................... Red if the RF link is not operational
E1 interface will transmit AIS on the affected E1 to indicate an error
RF Low ........................ Red if the received RF carrier level is
below -80 dBm.
PAGE 10 61280004L1-1A SECTION 1
The controls available from the control panel are listed below.
Name Function
Reset ............................ Reset the system
LBK .............................. Toggles E1 between normal and local line
loopback modes
CRC4 ON .................... Affects the E1 Performance Monitoring
characteristics. ES (errored second) is one or more CRC4 errors or Loss of Frame. SES (severely errored second) is more than one Loss of Frame, one or more Loss of Receive Signal or more than 805 CRC4 errors.
CRC4 OFF ................... Affects the E1 Performance Monitoring
characteristics. ES (errored second) is one or more BPV (bipolar violations) for an AMI configured circuit or one or more Code Errors for an HBD3 configured circuit. SES (severely errored second) is Loss of Signal or Frame, 805 or more BPV
(bipolar violations) or Code Errors.
CAS ..............................Selects Channel Associated Signalling
CCS .............................. Selects Common Channel Signalling
HDB3 ........................... Selects HDB3 Line Coding
AMI .............................. Selects AMI Line Coding
Remote Test ................. Initiate a remote test across the RF link
The monitor points provided on the front panel of the system are described below.
EYE I ............................ Demodulated received baseband output
EYE Q .......................... Demodulated received baseband output
EYE CLK...................... Recovered clock for observing EYE pattern
RSSI ............................. DC voltage indicating strength of the
received signal at the antenna
+5 ................................. System 5 volts
-5.................................. System -5 volts
+12 ............................... System +12 volts
-12................................ System -12 volts
RF PWR ....................... DC voltage supplying RF power
GND ............................ System ground
61280004L1-1A PAGE 11
TRACER DESCRIPTION
NON-VOLATILE MEMORY
The Tracer system contains non-volatile memory to retain certain configuration settings. These settings include:
Frequency plan Chipping code (if set from VT-100) Password Password enabling Site name E1 line coding (if set from VT-100) E1 framing (if set from VT-100)
BUILT-IN TESTS
The Tracer has several features to aid in site setup and later debugging. These diagnostics include E1 loopbacks and a link test with BERT (Bit Error Rate Test) data. A link test is performed by pressing the test button. The remote unit will then send a pseudorandom data pattern and the local end will compute a BER. After the conclusion of the test, the remote end will automatically be instructed to terminate the pattern generation. If any bit errors are introduced, the Remote Test Fail LED will illuminate.
PAGE 12 61280004L1-1A SECTION 1
RADIO FREQUENCY CONVERTER OR RFC
The radio frequency converter (RFC) provides the radio frequency (RF) interface between the baseband processor and the antenna. The RFC is partitioned, functionally, into two major components
- the transmitter and the receiver.
The major connections illustrated are transmit signal, receive signal, and the IF signal connection.
The RFC unit is enclosed in a metal enclosure approximately
26.7cm x 14cm x 2.5cm and is mounted in a 515 mm rackmountable housing or mastmountable, weatherproof enclosure. The RFC is illustrated below.
RSSI
GND
TX-PWR
RX
IF TX
Figure 1-8. RFC Module
Three SMA connectors, located on the RFC module, provide RF and IF connection points. A test point is provided for monitoring the received signal strength indicator (RSSI). The voltage (relative to the GND test point) present on this test point represents the level of the received signal. This signal is used to align the antenna when installing the system and to verify the link is performing as designed. Another test point is provided to monitor the transmitter output power during system configuration. The only connections that must be made in the field are a coax connection between the baseband processor and the RFC and a coax connection between the RFC and the antenna. These connections require male, type N coax connectors.
The IF connector provides the connection between the baseband processor and the rackmounted or mastmounted RFC. (An 8” IF cable [ADTRAN part # 3125RF027@A] is provided for rackmount systems). The TO ANTENNA connection provides the connection between the RFC and the antenna.
61280004L1-1A PAGE 13
TRACER DESCRIPTION
RX
TX
RF1
SAW
2018 2058
PA
2321 2281
LPF
333
Splitter
AGC
IF
Splitter
AGC
RF2
Figure 1-9. RFC Block Diagram
The RFC module is enclosed in either an ETSI-compliant rackmount housing, or a weather-tight enclosure suitable for mastmounting near the antenna for enhanced system performance. The RFC mastmount and rackmount housings are illustrated below.
Figure 1-10. Front and Rear of Rackmount RFC Housing
WARNING
Housing Assembly and Guide
Mounting Clearances
for Mounting Bracket
Holes
Figure 1-11. Mastmount RFC Housing
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