This equipment has been tested and found to comply with the limits for an intentional radiator, pursuant
to Part 15, Subpart C of the FCC Rules. This equipment generates, uses, and can radiate radio frequency
energy. If not installed and used in accordance with the instructions, it may cause interference to radio
communications.
The limits are designed to provide reasonable protection against such interference in a residential
situation. However, there is no guarantee that interference will not occur in a particular installation. If
this equipment does cause interference to radio or television reception, which can be determined by
turning the equipment on and off, the user is encouraged to try to correct the interference by one or more
of the following measures:
•Reorient or relocate the receiving antenna of the affected radio or television.
•Increase the separation between the equipment and the affected receiver.
•Connect the equipment and the affected receiver to power outlets on separate circuits.
•Consult the dealer or an experienced radio/TV technician for help.
W A R N I N G
Changes or modifications not expressly approved by ADTRAN could void the user’s authority to
operate the equipment.
Shielded Cables
A shielded-type power cord is required in order to meet FCC emission limits and also to prevent
interference with nearby radio and television reception when using the AC voltage adapter. It is essential
that only the Adtran-provided power cord be used.
FCC Output Power Restrictions
The FCC does not require licensing to implement this device. However, the FCC has established
restrictions regarding maximum output power and the adjustments required when employing directional
gain antennas. (Refer to “Setting the Transmitter Power” in Section 2 of this manual). These restrictions
are detailed in FCC Part 15.247 (b)(1), (b)(3)(i), and (3)(iii). It is the responsibility of the individuals
designing and implementing the radio system to assure compliance with these and any other pertinent
FCC Rules and Regulations. This device must be professionally installed.
Exposure to Radio Frequency Fields
The TRACER is designed in three versions with the following power options:
2.4 GHz @ 100 mw
2.4 GHz @ 1 w
5.8 GHz @100 mw
These levels of RF energy in are below the Maximum Permissible Exposure (MPE) levels specified in
FCC OET 65:97-01. The installation of high gain antenna equipment in the system configuration may
create the opportunity for exposure to levels higher than recommended for the general populationat a
distance less than 15 feet (4.6 meters) from the center of the antenna. The following precautions must be taken
during installation of this equipment:
TRACER 2xT1 User’s Manuali
Preliminary
61280003L2-1B
Radio Frequency Interference Statement
•The installed antenna must not be located in a manner that allows exposure of the general
population to the direct beam path of the antenna at a distance less than 15 feet (4.6 meters). Installation on
towers, masts, or rooftops not accessible to the general population is recommended; or
• Mount the antenna in a manner that prevents any personnel from entering the area within 15 feet (4.6
meters) from the front of the antenna.
• It is recommended that the installer place radio frequency hazard warnings signs on the barrier that
prevents access to the antenna.
• Prior to installing the antenna to the RFC output, make sure the power is adjusted to the settings
specified in section 2 of this manual.
• During antenna installation, be sure that power to the TRACER equipment is turned off in order to
prevent any energy presence on the coaxial connector.
• During installation and alignment of the antenna, do not stand in front of the antenna assembly.
• During installation and alignment of the antenna, do not handle or touch the front of the antenna.
These simple precautions must be taken to prevent the general population and installation personnel from
exposure to RF energy in excess of specified MPE levels.
3-12.Configuration Menu ................................................................................................... 34
3-13.Remote Current System Status ................................................................................... 35
viii
Preliminary
TRACER 2xT1 User’s Manual
61280003L2-1B
SECTION 1TRACER DESCRIPTION
Section 1 TRACER Description
INTRODUCTION
The TRACER provides dual T1 transport by way of a spread spectrum microwave link for distances up
to 30 miles or more depending on path engineering. System performance is determined, in part, by the
engineering of the microwave link. Each end of a TRACER link is composed of two units -- the
baseband processor (BBP) and the radio frequency converter (RFC). Two DS1/DSX-1 (T1) interfaces
are provided on the rear of the BBP, which can be mounted in a 19-inch rack. The DS1/DSX-1 interface
provides connections up to 6000 feet from T1 equipment. A single coaxial cable connects the BBP to the
RFC and another connects the RFC to the antenna.
ISM BAND SPREAD SPECTRUM
The Federal Communications Commission (FCC) has established several portions of the radio frequency
(RF) spectrum for use in Industrial, Scientific, and Medical (ISM) applications. Part 15.247 of the FCC
rules describes the requirements of systems that operate in these bands. The three bands set aside,
902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz, are designated for use by spread spectrum
transmitters, either frequency hopping or direct sequence. The TRACER operates in the 2400 to 2483.5
MHz or 5725-5850 MHz band using direct sequence spread spectrum (DSSS) transmission.
NEBS
Network Equipment Building Standards (NEBS) defines a rigid and extensive set of performance,
quality, environmental and safety requirements developed by Telcordia, the R&D and standards
organization owned by the seven regional Bell operating companies (RBOCs). NEBS compliance is
often required by telecommunications service providers such as BOCs (Bell Operating Companies) and
Interexchange Carriers (IEC) for equipment installed in their switching offices. NEBS defines everything
from fire spread and extinguish ability test to Zone-4 earthquake tests, thermal shock, cyclic temperature,
mechanical shock, and electro-static discharge. TRACER is NEBS Level 3 compliant (see Table 1-1
for a list of testing requirements.)
Table 1-1. NEBS Testing Requirement
Document
GR-63 Operational Thermal
(Short Term Conditions)
Storage Environments and Transportation
and Handling
Earthquake (Zone 4 Level)
Airborne Contaminants (Outdoor Levels)
GR-1089 ESD (Installation and Repair)
EMI Emissions (Open Doors)
EMI Immunity (Open Doors)
Steady State Power Induction
Conditional Requirements
Description
R4-6/72 Equip. should withstand exposure to “Table 4-4 Short T”
R4-7/73 Equip should withstand exposure to “Table 4-5 Short T”
R4-3 - R4-5/69-70 Exposure to tests in Tables 4-2, 4-3
R4-41- R4-43/107-109 Packaged and Unpackaged shock criteria
R4-58/124 Transportation vibration criteria
R4-44 - R4-46/110-112 Equipment and Frame Level testing of Section 5.4.1
R4-48/114 Functional requirements testing of Section 5.4.1
O4-49/115 Constructed to meet testing of Section 5.4.1
R4-51/117 Base mounting to floor without auxiliary support
R4-53/119 Specs for concrete anchors
O4-60/126 Equipment should withstand testing “Table 4-10”
R4-61/127 Equipment should withstand testing “Table 4-10” and o.s.air
CR5-2/43 Signaling - test to Table 5-1 (>20 ft)
CR5-4/45 C-Message -Signaling-test to test condition (>20 ft)
CR5-9/50 Signaling - test to Table 5-3 (>20 ft)
CR5-11/52 C-Message weighted metallic noise test (>20 ft)
TRACER 2xT1 User’s Manual
1Preliminary
61280003L2-1B
Section 1 TRACER Description
APPLICATIONS
Any application that would typically use metallic T1 as a transport can use the TRACER instead. Figure
1-1 illustrates a typical application.
AntennaAntenna
RF Cable
Mast Unit
TRACER
Baseband Processor
VT-100
RS-232
Terminal
T
R
A
C
E
R
T
1
T
1
T
RA
N
SC
B
EI
B
P
O
W
A
I
S
A
I
S
D
A
T
A
D
A
T
A
T1
T1
Switch
MSC
2xT1, Mast-mounted RFC
IF Cable
RF Cable
TRACER
Baseband Processor
T
Rack-mount RFC
R
A
C
E
R
T
1
T
1
T
R
A
N
B
S
C
P
E
I
B
P
O
W
A
I
S
A
I
S
D
A
T
A
D
A
T
A
T
R
A
C
E
R
T1
T1
Cell Radio
Cellular/PCS Site
2xT1, Rack-mounted RFC
Mast and Rack mount RFCs may be mixed to accommodate individual system requirements.
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 internetworking, 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.” The FCC rules allow two methods of spreading – frequency hopping and direct
sequence. TRACER employs direct sequence spread spectrum.
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 noise-like, 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
2Preliminary
TRACER 2xT1 User’s Manual
61280003L2-1B
Section 1 TRACER Description
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
The FCC has allocated 83.5 MHz of spectrum in the 2.4 GHz band and 125 MHz in the 5.8 GHz band in
which TRACER operates. A TRACER system fully uses the available bandwidth – transmitting in one
half and receiving in the other. Figure 1-2 illustrates the bandwidth division.
2400 MHz
5725 MHz
Figure 1-2. Bandwidth Division
2441 MHz
or
5787 MHz
2483.5 MHz
5850 MHz
The transmitter at one end (TxA) 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 otherwise
specified.
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 re-transmission 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 signal-tonoise (S/N) ratio by approximately 5.5 dB to achieve a given bit error rate (BER).
T1 Operation
Framing
The data in a T1 stream is delimited by framing bits. The pattern of the framing bits follows one of two
formats -- extended superframe ( ESF) or superframe (SF). The T1 interface must be prepared for the
format that will be used.
TRACER 2xT1 User’s Manual
3Preliminary
61280003L2-1B
Section 1 TRACER Description
Line Code
A mark in the data stream is coded as a pulse on the T1 line. A space is coded as “no activity” on the T1
line. As a form of error detection, subsequent marks in the data stream are coded as pulses of alternating
polarity, either positive going or negative going. This type of line coding is called alternate mark
inversion (AMI).
For the T1 receiver to operate correctly, a minimum number of “1s” must exist on the T1 facility. If the
data cannot be guaranteed to meet this requirement, then another line coding format is used. In the
bipolar 8 zero substitution (B8ZS) scheme, a string of eight “0s” is replaced by a special sequence of
eight bits that contains a bipolar violation. The receiver, upon recognizing this sequence, reinserts the
eight “0s” and the data is recovered intact.
DS1/DSX-1 Interface
When connecting the interface to the public switched network, an ADTRAN-provided cross-over cable
(part number 3125M011@A) is required to meet FCC part 68 and IC CS03 requirements. This cable is
required to cross-over the Tx and Rx pairs to meet the connecting arrangement of a network interface
device. This cable is included with the BBP and is labelled “T1 Crossover.”
Line Buildout or LBO
The DS1/DSX-1 interface provides two different types of line buildouts (LBOs), respectively. When set
for DS1, LBOs for 0 dB, -7.5 dB, -15 dB, and -22 dB are available. The DS1 interface can operate on
line lengths up to 6,000 feet. When set for DSX-1 interface, LBOs for 0-133 feet, 266-399 feet, 399-533
feet, and 533-655 feet are available.
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 BBP (ADTRAN part number 1280003L2) is a 1-U, 19-inch rackmountable unit that provides the
system electrical interfaces, user controls and indicators, and performs the spread spectrum processing
for the system. The rear panel provides all of the electrical interface points -- DS1/DSX-1 interface,
DS1/DSX-1 monitor, VT-100 terminal, alarm contacts, IF signal, DC power (from facility), and power
(from AC adapter). The BBP and its rear panel are illustrated in Figure 1-3 and 1-4.
POWER
T1A
TEST
YEL/AIS
BPV
LBK
RED
T1B
BPV
LBK
YEL/AIS
RED
PLAN A
PLAN B
FREQ
SYSTEM
RF LOW
LINK DOWN
Figure 1-3. BBP
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TRACER 2xT1 User’s Manual
61280003L2-1B
Section 1 TRACER Description
MANAGEMENT
Figure 1-4. BBP Rear Panel
DS1/DSX-1 Interface
Two DS1/DSX-1 interfaces, labelled “T1A” and “T1B,” are provided for connecting to the T1
equipment. Two types of physical interfaces are provided -- RJ-48C and bantam jacks.
The interfaces are illustrated in Figure 1-5, BBP Block Diagram. The functions of the BBP are
partitioned into three printed circuit boards or PCBs, all contained in the same enclosure.
Baseband Processor Board
RS-232
µCUARTDSP
T1A
T1B
IF
-48Vdc
T1
T1
T1C
Multiplex
Fc = 140 MHz
Filter
Fc = 70 MHz
IF Interface Board
Viterbi
Encoder/
Decoder
Σ
Spread
Spectrum
Data
Pump
90
90
Figure 1-5. BBP Block Diagram
The DS1/DSX-1 interfaces provided for each channel are the same. The upper bantam connectors,
labeled “Monitor,” provide isolated monitor points for testing. The lower bantam jacks provide signal
insertion points. The insertion of a bantam jack disconnects the RJ-48C connector from the circuit. The
DS1/DSX-1 interface can operate on line lengths up to 6000 feet.
When connecting either T1 interface to the public switched network, an ADTRAN-provided cross-over
cable (part number 3125M011@A) is required to meet FCC part 68 and IC CS03 requirements. This
cable is included with the BBP and is labelled “T1 Crossover.” This cable is required to cross-over the
TX and RX pairs to meet the connecting arrangement of a network interface device.
For connections to other CPE-type equipment, such as an ADTRAN TSU-100, a straight-through T1
cable is provided by ADTRAN (part number 3127004) and is included with the BBP.
TRACER 2xT1 User’s Manual
5Preliminary
61280003L2-1B
Section 1 TRACER Description
VT-100 RS-232 Interface
A serial interface port using RS-232C signal levels is provided for attaching a VT-100-compatible
terminal. The connection is made via a DB-25 connector on the rear panel. The data rate is configured
for 9600 bps, 8 data bits, no parity, and 1 stop bit.
A 7-day error history of the T1 interfaces and radio link is also provided. Fifteen-minute histories are
provided for the most recent 24 hours of operation.
Alarm Contacts
Two sets of alarm contacts are provided on the rear of the BBP: major alarm and minor alarm. A major
alarm indicates the radio link is not operational. A minor alarm indicates that system performance is
degraded or that the T1 interfaces are experiencing errors. Normally-open and Normally-closed contacts
are provided for both alarm types. Under normal operating conditions there is no continuity between the
Normally-open and Common contacts, and, under an alarm condition, continuity between those contacts
exists. The Normally-closed and Common contacts normally have continuity, while under alarm
conditions, these contacts are open.
IF Signal
The N-type connector on the rear panel provides the interface point between the BBP and the RFC. This
connection provides the data 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 cable has been determined.
Power
The unit receives power via one of two connectors. Power for the entire system is provided by these
interfaces. The three-pin circular DIN connector is provided to connect an optional ADTRAN desktop
AC adapter (ADTRAN part number 1360DSK24VL1), 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 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 Figures 1-6 and 1-7.
TEST
POWER
T1A
BPV
LBK
YEL/AIS
RED
T1B
BPV
LBK
YEL/AIS
RED
PLAN A
PLAN B
FREQ
SYSTEM
RF LOW
LINK DOWN
Figure 1-6. BBP Front Panel (with door closed)
6Preliminary
TRACER 2xT1 User’s Manual
61280003L2-1B
Section 1 TRACER Description
UP
DOWN
Figure 1-7. BBP Front Panel (with door open)
Options that are set from the front panel can be overridden via the terminal interface. 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.
Test ...............................Red indicates that the self-test has completed and failed
PWR .............................Green indicates that DC voltage is applied
The LEDs associated with the DS1/DSX-1 interfaces are listed below. There are two sections of
identical indicators -- one for each DS1/DSX-1 interface.
BPV ..............................Red if the incoming T1 stream contains bipolar
violations
RED..............................Red if there is no signal present at the T1 interface
LPBK............................Yellow if the T1 interface is in loopback
YEL/AIS ......................Flashes to indicate a T1 Yellow Alarm; remains On
(solid) to indicate an AIS alarm (when the DS1/DSX-1
is receiving a Blue code)
The LEDs indicating error conditions are listed below.
RF Low.........................Red indicates the received RF carrier level is too low
Link Down ...................Radio path is down
The front panel controls are listed below.
Reset .............................Reset the system
LBKA ...........................Toggles the T1-A between no loopback and line
loopback
LBO..............................Selects TI line buildout. Template on right edge of
faceplate designates switch setting.
LBKB ...........................Toggles the T1-B between no loopback and line
loopback
TRACER 2xT1 User’s Manual
7Preliminary
61280003L2-1B
Section 1 TRACER Description
Tx PWR........................UP increments radio transmit power up.
DOWN increments radio transmit power down.
VT100 terminal will indicate Tx Power setting.
Remote Test .................Initiate a remote test across the RF link
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
T1 line coding (if set from VT-100)
T1 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 T1
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.
The monitor points provided on the front panel of the system are listed on the next page.
I......................................Demodulated received baseband output
Q ....................................Demodulated received baseband output
CLK...............................Recovered clock for observing EYE pattern
RSSI ..............................DC voltage indicating strength of the received signal at
RF PWR ........................Voltage supplying RF power
GND ..............................System ground
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 in Figure 1-8 are transmit signal, receive signal, and the IF signal
connection.
The RFC unit is enclosed in a metal enclosure approximately 9.5 inches x 5.5 inches x 1 inch and is
mounted in a 1-U, 19-inch rackmountable housing or mastmountable, weatherproof enclosure.
8Preliminary
TRACER 2xT1 User’s Manual
61280003L2-1B
Section 1 TRACER Description
R
S
S
I
G
N
D
T
X
-P
W
R
R
X
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.
I
F
T
X
The IF connector provides the connection between the baseband processor and the rackmounted or
mastmounted RFC. (An 8-inch IF cable [ADTRAN part # 3125RF027@A] is provided for rackmount
systems). The TO ANTENNA connection provides the connection between the RFC and the antenna. A
block diagram of the RFC functions is show in Figure 1-9.
The RFC module is enclosed in either a 19-inch EIA 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 in Figures 1-10 and 1-11.
Rx
Tx
20185344
or
20585424
PA
2321
2281
SAW
or
5607
5687
LPF
333
Splitter
AGC
RF2
Splitter
AGC
IF
TRACER 2xT1 User’s Manual
Figure 1-9. RFC Function Block Diagram
9Preliminary
61280003L2-1B
Section 1 TRACER Description
Figure 1-10. Mastmount RFC Housing
Figure 1-11. Rackmount RFC Housing
Antenna
TRACER is intended to be coupled with an antenna that is directional and provides signal gain. There
are several reasons for this requirement:
•TRACER operates in point-to-point applications; therefore, an omnidirectional antenna is
not needed.
•The FCC provides no recourse in this band in the event of nearby interference, so a highly
directional antenna reduces the likelihood of interference in the antenna pattern.
•The low power transmitter is intended to be used with a high-gain antenna for long links.