Wireless WaveNet Link AX User manual

WaveNet Link AX
ATM-25 U-NII Band
Digital Radio System
Installation and Operations Manual
Part Number 100273-001
Version 0.8
October 2000
Wireless Inc.
5452 Betsy Ross Drive
Santa Clara, CA. 95054-1101
[phone]

ii
WaveNetLinkAXInstallationandOperationsManual
Notice
Information in this document is subject to change without notice. No part of this document may
be reproduced or transmitted in any form or by any means, electronic or mechanical, for any
purpose, without the express written permission of Wireless, Inc.
© Copyright 2000, Wireless, Inc. All rights reserved.
Link AX™and WaveNet Link™Series are trademarks of Wireless, Inc.

iii
WaveNetLinkAXInstallationandOperationsManual
Table of Contents
1.0 General Overview ................................................................................................................. 1
1.1 WaveNet Link Series Product Family........................................................................ 1
1.2 Introduction to the Link AX ........................................................................................ 1
1.3 Regulatory Information .............................................................................................. 2
2.0 Link AX Product Profile ......................................................................................................... 3
2.1 General Overview...................................................................................................... 3
2.2 Specifications ............................................................................................................ 5
2.3 User Interfaces .......................................................................................................... 8
2.4 ODU Performance Monitoring ................................................................................... 8
2.5 Theory of Operation .................................................................................................. 9
3.0 Equipment Installation and Commissioning ........................................................................ 15
3.1 Installation ............................................................................................................... 15
3.2 ATM25 Data Connectors ......................................................................................... 19
3.3 Connect the Power Supply ...................................................................................... 19
3.4 Outdoor RF Unit Installation .................................................................................... 20
3.5 Indoor Unit ............................................................................................................... 27
3.6 DIP Switch Function and Configuration .................................................................. 28
3.7 Commissioning ........................................................................................................ 30
4.0 Antenna Installation............................................................................................................. 35
4.1 Equipment Inventory List ......................................................................................... 35
4.2 Antenna Installation and Rough Alignment ............................................................. 36
4.3 RF Cable Install and Seal........................................................................................ 50
5.0 Maintenance and Troubleshooting...................................................................................... 63
5.1 Link AX Maintenance .............................................................................................. 63
5.2 Where to get Further Assistance............................................................................. 64
5.3 Return Procedure .................................................................................................... 65
Appendix A Grounding Practices and Lightning Protection Information....................................... A-1

iv
WaveNetLinkAXInstallationandOperationsManual
Figures
Figure 2.1 Typical Deployment of a Link AX in a Point-to-Point Configuration ............................. 4
Figure 2.2a Outdoor Unit, Front View ............................................................................................ 10
Figure 2.2b Outdoor Unit, Back View ............................................................................................ 10
Figure 2.2c Outdoor Unit, Front View, Integral Antenna ............................................................... 11
Figure 2.2d Outdoor Unit, Back View, Integral Antenna ............................................................... 11
Figure 2.3 Link AX Indoor Unit (IDU) ........................................................................................... 13
Figure 2.4 Link AX Block Diagram............................................................................................... 14
Figure 3.1 Power Cord Connection ............................................................................................. 19
Figure 3.2 Outdoor Unit Mounting Hardware .............................................................................. 20
Figure 3.3 Attaching the Pole or Tilt Mount Adaptor Bracket ...................................................... 21
Figure 3.4 Mounting the Outdoor RF Unit to the Bracket ............................................................ 22
Figure 3.5a Mounting Bracket Latch and Stud Mount Detail......................................................... 23
Figure 3.5b Locking the Mounting Hardware ................................................................................ 24
Figure 3.6a N-Type Antenna and Siamesed Ethernet/Power Connections .................................. 25
Figure 3.6b Ground Connection ....................................................................................................26
Figure 3.7 Link Ax Indoor Unit (IDU) ........................................................................................... 27
Figure 3.8 DIP Switch Access and Configuration Information .................................................... 29
Figure 3.9 Receive Signal Level ..................................................................................................34
Figure 4.1 Antenna Mount ........................................................................................................... 36
Figure 4.2 Adjustable Panel Antenna Mount ............................................................................... 37
Figure 4.3 Flat Panel Antenna ..................................................................................................... 38
Figure 4.4 Adjustable Flat Panel Mount ...................................................................................... 39
Figure 4.5 24”Flat Panel Quick Align Mount............................................................................... 40
Figure 4.6 24”Diameter Antenna ................................................................................................ 41
Figure 4.7 Mount Configuration ...................................................................................................43
Figure 4.8 Mounting Hardware Packed ....................................................................................... 46
Figure 4.9 Mounting Hardware Unpacked ................................................................................... 46
Figure 4.10 Parabolic Reflector ..................................................................................................... 47
Figure 4.11 Unpacking the Radome .............................................................................................. 47
Figure 4.12 Antenna Mounting Assembly ..................................................................................... 48
Figure 4.13 Antenna Mount Assembly .......................................................................................... 49
Figure 4.14 Elevation Rod Assembly ............................................................................................ 49
Figure 4.15 Feed Horn Assembly .................................................................................................. 50
Figure 4.16 Feed Horn Polarization Markings ............................................................................... 51
Figure 4.17 Parabola Rear View Showing Polarization Reference Markers ................................. 51
Figure 4.18 Feed Horn Installation ................................................................................................ 52
Figure 4.19 Feed Horn Installation for Vertical Polarized Operation ............................................. 52
Figure 4.20 Azimuth Clamp/Shear Stop Assembly ....................................................................... 53

v
WaveNetLinkAXInstallationandOperationsManual
Figure 4.21 Azimuth Adjustment Clamp Assembly ...................................................................... 53
Figure 4.22 Hoisting the Antenna ................................................................................................. 54
Figure 4.23 Adjustable Parabolic Antenna Mount ....................................................................... 57
Figure 4.24a Feed Assembly Plane Polarized ............................................................................... 58
Figure 4.24b Feed Assembly Plane Polarized ............................................................................... 59
Figure 4.25 Ground Connection ...................................................................................................60
Figure 4.26 RF Cable Install and Seal ......................................................................................... 61
Tables
Table 1.1 FCC U-NII Bands ......................................................................................................... 2
Table 2.1 Connector Pin Assignment, ATM Connector on ODU ................................................. 6
Table 2.2 Connector Pin Assignment, Power Supply Input Connector on ODU ......................... 6
Table 2.3 Recommended Antennas ............................................................................................. 7
Table 3.1 Maximum Transmit Power Level Setting vs. Antenna Type (for compliance with
FCC EIRP limits) in the 5.3 GHz Band....................................................................... 16
Table 3.2 Maximum Transmit Power Level Setting vs. Antenna Type (for compliance with
FCC EIRP limits) in the 5.7 GHz Band, Original and July 31, 1998 rules.................. 17
Table 3.3 List of Tools ................................................................................................................ 18
Table 3.4 Inventory of Equipment and Installation Materials ..................................................... 18
Table 3.5 Connector Pin Assignment, ATM Connector on ODU ............................................... 19
Table 3.6a Connector Pin Assignment, ATM Connector on ODU ............................................... 27
Table 3.6b Connector Pin Assignment, ATM Connector on ODU ............................................... 27
Table 3.6c IDU LED Status .......................................................................................................... 27
Table 3.7 DIP Switch Configuration ........................................................................................... 28
Table 3.8 Installation Checklist................................................................................................... 30
Table 3.9 RSSI Voltage vs. Receive Signal Level ..................................................................... 32
Table 3.10 Approximation Table .................................................................................................. 32
Table 4.1 Inventory of Equipment and Installation Materials ..................................................... 35
Table 4.2 Approximation Table of Flat Panel Antennas............................................................. 36
Table 4.3 Approximation Table of Parabolic Antennas .............................................................. 41
Table 4.4 24”Diameter Antenna Dimensions ............................................................................ 42
Table 4.5a Contents List, Mount Assembly.................................................................................. 44
Table 4.5b Contents List, Mount Assembly.................................................................................. 45
Table 4.5c Contents List, Feed Assembly ................................................................................... 45
Table 4.5d Contents List, Reflector Assembly ............................................................................. 45
Table 4.6 Nut Tightening Procedures ........................................................................................ 56

vi
WaveNetLinkAXInstallationandOperationsManual
Welcome!
Welcome to the Wireless, Inc. WaveNet Link™Series product family. This manual is designed
to introduce you to the Link AX™, and to provide you with information necessary to plan, install,
operate and maintain a Link AX wireless communication system.
The Link AX is intended for professional installation only. This manual, however, is also
designed for personnel who plan, operate and administrate the Link AX communication system.
Please review the entire manual before powering up or deploying any Link AX.
Updates to this manual will be posted on the Wireless, Inc. Customer Service Website at
http://www.wire-less-inc.com . Registered Wireless customers can access Wireless’on-line
information and support service, available 24 hours a day, 7 days a week. Our on-line service
provides users with a wealth of up-to-date information, with documents being added or updated
each month.
Radiation Warnings
Microwave Radio Radiation Warning
Under normal operating conditions, Link AX radio equipment complies with the limits for human
exposure to radio frequency (RF) fields adopted by the Federal Communications Commission
(FCC). All Wireless, Inc. microwave radio equipment is designed so that under normal working
conditions, microwave radiation directly from the radio is negligible when compared with the
permissible limit of continuous daily exposure recommended in the United States by ANSI/IEEE
C95.1-1991 (R1997), Safety Levels with Respect to Human Exposure to Radio Frequency
Electromagnetic Fields, 3 kHz to 300 GHz.
Microwave signal levels that give rise to hazardous radiation levels can exist within transmitter
power amplifiers, associated RF multiplexers, and antenna systems.
Never look into the open end of a Waveguide as eyes are particularly vulnerable to radiation.
Do not disconnect RF coaxial connectors, open microwave units, or break down any
microwave screening while the radio equipment is operating.

vii
WaveNetLinkAXInstallationandOperationsManual
Microwave Antenna Radiation Warning
Designed for point-to-point operation, a Link AX microwave radio system uses directional
antennas to transmit and receive microwave signals. These directional antennas are usually
circular or rectangular in shape, and are usually mounted outdoors on a tower or mast, well
above ground level.
Referencing OET Bulletin 65 (Edition 97-01, August 1997) from the Federal Communication
Commission’s Office of Engineering & Technology, limits for maximum permissible exposure
(MPE) to microwave signals have been adopted by the FCC for General Population/Uncon-
trolled environments. This limit is 1.0 mW/cm2, with averaging times of thirty-minutes.
The closer you are to the front center-point of a microwave antenna, the greater the power
density of its transmitted microwave signal. Unless you are very close, however, microwave
exposure levels will fall far below the MPE limits. To determine how close to a microwave
antenna you can be and still remain below the MPE limits noted above, “worst case”predictions
of the field strength and power density levels in the vicinity of an Link AX™microwave antenna
can be made from the following calculations. The equation is generally accurate in the far-field
of an antenna, and will over-predict power density in the near-field (i.e. close to the antenna).
S = PG/4πR2
where: S = power density (in mW/cm2)
P = power input to the antenna (mW)
G = power gain of the antenna in the direction of interest relative to an isotropic
radiator
R = distance to the center of radiation of the antenna (cm)
Note that G, the power gain factor, is usually expressed in logarithmic terms (i.e., dB), and must
be converted using the following equation:
G = 10 dB/10
For example, a logarithmic power gain of 17.5 dB is equal to a numeric gain of 56.23.
Assuming (1) maximum output power from the Link AX (+12 dBm [15.8 mW]), (2) no signal loss
in the cable connecting the Link AX to the antenna, and (3) the use of a 17.5 dBi gain flat panel
antenna, the 1.0 mW/cm2MPE power density limit would be reached at a distance of
approximately 8.4 cm. The Link AX is classified as a fixed installation product, and per FCC
policy guidelines regarding MPE, antennas used for this Wireless Inc. transmitter must be
installed to provide a separation distance of 2 meters (6 feet) or more from all persons during
normal operation to satisfy FCC RF exposure compliance.
Wireless, Inc. fully supports the FCC’s adopted MPE limits, and recommends that personnel
maintain appropriate distances from the front of all directional microwave antennas. Should you
have questions about Link AX microwave signal radiation, please contact the Wireless, Inc.
Customer Service Department.

viii
WaveNetLinkAXInstallationandOperationsManual
Point-to-Point Radio Operation
The Link AX microwave radio system is intended for point-to-point, line-of-sight applications
only. The antennas utilized in these applications are high gain, highly directive antennas, and
are intended for professional installation. Antennas should be mounted on permanent struc-
tures such as masts or towers, which are not accessible to the general public.
The installer shall mount the antennas as to comply with the limits for human exposure to radio
frequency (RF) fields per paragraph 1.1307 of the Federal Communication Commission (FCC)
Regulations. The FCC requirements incorporate limits for Maximum Permissable Exposure
(MPE) in terms of electric field strength, magnetic field strength, and power density.
It is the responsibility of the installer to ensure the antennas are used with the Link AX radio,
are designed for fixed point-to-point operations, and their use with the radio complies with FCC
limits stated in Part 15.407.
The following information is supplied pursuant to FCC Regulations (Part 15.407) for unlicensed
intentional radiators:
The Link AX conforms to the regulations in CFR 47, Part 15.407 pertaining to unlicensed point-
to-point use. Modifications to the equipment, which would alter the conditions of the Equipment
Grant of Authorization are strictly prohibited, and may void the user’s right to operate the
equipment.
Notice Regarding Operation pursuant to FCC part 15 Rules
This equipment has been tested and found to comply with the limits for a Class A digital device
pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a residential area is likely
to cause harmful interference in which case the user will be required to correct the interference
at his own expense.

1
WaveNetLinkAXInstallationandOperationsManual
1.0 General Overview
1.1 WaveNet Link Series Product Family
All Link AX radios are members of the WaveNet Link Series radio product family. The WaveNet
Link Series is designed to provide an economical wireless solution for local access telecommu-
nication requirements.
This manual addresses, in detail, the operation of the Link AX. For detailed information on
other members of the WaveNet Link Series, please refer to the appropriate Operation
Manual(s).
1.2 Introduction to the Link AX
The Link AX is a digital radio designed for use as a point-to-point communications system. The
Link AX is used in the following applications:
Wireless DSL
Point-to-point (building to building)
Internet Service Providers (ISPs)
Local Exchange Carriers (LECs)
Wireless Local Loop (WLL)
Backup Solutions
Temporary Links
The Link AX radio is designed for operation in two of the Unlicensed National Information
Infrastructure (U-NII) bands at frequencies of 5.250 - 5.350 GHz and 5.725 - 5.825 GHz.
Each Link AX is comprised of a pole mounted RF/antenna unit. Each radio is powered by means
of a DC power supply (optional AC-DC power supply available) which is fed to the unit through
a power/data cable. The system has a total data transmission capacity of 8 Mps full-duplex.
Refer to the Link AX data sheets for detailed information relating to product offerings and
specifications.

2
WaveNetLinkAXInstallationandOperationsManual
Table 1.1 - FCC U-NII Bands
1.3 Regulatory Information
In January 1997, the FCC made available 300 MHz of spectrum for Unlicensed National
Information Infrastructure (U-NII) devices. The FCC believes that the creation of the U-NII band
will stimulate the development of new unlicensed digital products which will provide efficient
and less expensive solutions for local access applications.
The U-NII band is divided into three sub bands at 5.15 - 5.25, 5.25 - 5.35 and 5.725 - 5.825 GHz.
The first band is strictly allocated for indoor use and is consistent with the European High
Performance Local Area Network (HIPERLAN). The second and third bands are intended for
high speed digital local access products for “campus”and “short haul”microwave applications.
1dnaB2dnaB3dnaB
ycneuqerF zHG52.5ot51.5zHG53.5ot52.5zHG528.5ot527.5
)xaM(rewoP PRIEsttawillim002 )PRIE(ttaw1
mBd03+
)PRIE(sttaw4
mBd63+
esUdednetnI ylnOesUroodnIsupmaCselim01xorppA
enuJnodesiver)00M(redrodnanoinipomudnaromemCCFnA:etoN*
adnaniagiBd32htiwannetnalanoitceridafoesuehtswolla8991,42
IIN-U528.5-527.5ehtnittaw1forewoptuptuorettimsnartmumixam
.dnab
100202LW

3
WaveNet Link AX Installation and Operations Manual
2.0 WaveNet Link AX Product Profile
2.1 General Overview
The Link AX microwave radio provides digital capacities for 16 Mb/s data rates (8Mb/s full-
duplex) for distance of up to 15 km. The radio terminal operates in the Unlicensed National
Information Infrastructure (U-NII) spectrum with a Split Modulation system architecture that
provides full duplex operation in the 5.3/5.7 GHz U-NII frequency bands.
The product uses two separate 100 MHz bands within the U-NII frequency spectrum. Within
these bands, the Link AX series operates in one of many independent channels providing for
frequency reuse and network flexibility, ideal for dense network applications.
Synthesized RF channel selection is field configurable, as are the power output options for the
selection of antenna sizes.
Complying with all aspects of FCC Rules Subpart 15.401-15.407, the transmission character-
istics of the Link AX series are designed to meet the peak power spectral density requirements
of the U-NII 5.250 - 5.350 and 5.725 - 5.825 GHz bands.
The Link AX has been designed for easy access to all interfaces, controls, and displays.
Information in this manual will familiarize you with all of these items. Figure 2.1 illustrates two
(2) Link AX terminals in a point-to-point configuration.
The Link AX is avaialble with two types of Outdoor Unit/Antenna configurations:
External Antennas : Requires the use of an external antenna (parabolic or flat panel
type), and the connection between ODU and antenna is per-
formed via the use of a 2-meter (6 feet) piece of RG8 type cable.
Typically this can be used for longer link distances up to 9 miles
(15 km).
Integral Antennas: A 9”flat panel antenna is integrated into the ODU housing, and
is internally connected. Typically this can be used for short link
distances up to 4 miles (6 km).

4
WaveNetLinkAXInstallationandOperationsManual
RSSI Test Point
1 Meter
ODU-Antenna
Interconnect
Cable
Data / Power Cable
RSSI Test Point
Data
21-56
VDC
Data
21-56
VDC
Link AX
5.3 GHz TX
Outdoor
Element
Indoor
Elements
Power Supply Link AX IDU
(optional)
Site A Site B
Antenna
5.3/5.8 GHz
Indoor
Elements
Antenna
5.3/5.8 GHz
Link AX
5.8 GHz TX
1 Meter
ODU-Antenna
Interconnect
Cable
Data / Power Cable
Power Supply
Antenna
Mount
Link AX IDU
(optional)
Antenna
Mount
Radio
Mount Kit
Radio
Mount Kit
WL292004
Figure 2.1 - Typical Deployment of a Link AX in a Point-to-Point External Antenna Configuration

5
WaveNet Link AX Installation and Operations Manual
2.2 Specifications
2.2.1 General Specifications
Frequency Range: 5.250 - 5.350 GHz and 5.725 - 5.825 GHz
RF Channel Bandwidth: 12 MHz
Channel Increments: 10.24 MHz
Radio Operation: Full duplex
Antenna Port Impedance: 50 ohms nominal
Ethernet Data Rate: 8 Mbps full duplex
2.2.2 ATM Interface
Type: ATM-25
Distance: 100 meters (330 ft) max
Termination: 100 ohm or 120 ohm RJ45 (user device per ATM 25.6
forum specification af-phy-0040.000)
ATM Traffic Parameters:
Parameter Description Min Typical Max Unit
PCR Peak Cell Rate 59259 Cps
SCR Sustained Cell Rate 15645 19200 19555 Cps
MBS Maximum Burst Size 3 Cell
MCR Minimum Cell Rate 0 Cps
2.2.3 Transmitter Specifications
Frequency Range: 5.250 - 5.350 GHz and 5.725 - 5.825 GHz
Channel Increments: 10.24 MHz
Modulation: BPSK
Power Output: 0, +4, +8, and +12 dBm
Transmit Duty Cycle: 100%
Emission Mask: Per FCC 15.407
Frequency Stability: ±5 ppm
Data Rate: 8 Mbps
2.2.4 Receiver Specifications
Type: Coherent Detection
Sensitivity for 1x10-6 BER: -83 dBm
Receiver Overload for 1x10-6 BER -30 dBm
Maximum RF Input (no damage): -20 dBm
Data Rate: 8 Mbps
Channel Increments: 10.24 MHz

6
WaveNetLinkAXInstallationandOperationsManual
The 4-pin CircularMil power supply input connector pin assignments are shown in Table 2.2.
Note: The white lead of the power side of the Data/Power cable connects to Pin 1, thus it
should be connected to the negative lead of the power source. The red lead of the power
side of the Data/Power cable connects to Pin 2, thus it should be connected to the positive
lead of the power source.
2.2.7 Antennas
2.2.5 Digital Interface
ATM Interference on ODU
The 8-pin CircularMil (ATM interface/ODU status signals) connector pin assignments are
shown in Table 2.1.
2.2.6 Power Supply Input Connector on ODU
Table 2.1 - Connector Pin Assignment, ATM Connector on ODU
Table 2.2 - Connector Pin Assignment, Power Supply Input Connector on ODU
niPDAELNOITPIRCSED
1+XT+timsnarTriaPdetsiwT
2-XT-timsnarTriaPdetsiwT
3MLA/RWPUDInoDEL"mralAlacoL/rewoP"sevirdtahtlangiS
4ISSRhtgnertslangisgntacidniegatlovgolanA
5DNGAISSRrofdnuorG
6DNGDDELmralA/rewoProfdnuorG
7+XR+evieceRriaPdetsiwT
8-XR-evieceRriaPdetsiwT
300202LW
niPdaeLnoitcnuFroloC
1)-(tupnIevitageN.ylppusrewopfodaelevitagenotnoitcennoCetihW
2)+(tupnIevitisoP.ylppusrewopfodaelevitisopotnoitcennoCdeR
3desUtoN
4desUtoN
400202LW
Note: Pins 3-6 are used in conjunction with the Indoor Unit for test and maintenance purposes only.
Refer to DIP switch settings on page 34 for details. When connecting to a Network device, only pins
1,2,7, and 8 are used.

7
WaveNet Link AX Installation and Operations Manual
epyTrebmuNtraPdnarerutcafunaM
iBd81,deziraloPenlP,lenaPtalFdetargretnI"9 2.5-57.PFWsevaWoidaR
iBd5.71,deziraloPenalP,lenaPtalF"625-5.DPFDleirbaG
iBd32,deziraloPenalP,lenaPtalF"2125-1DPFDleirbaG
iBd3.32deziraloPenalP,hsidretemaid"21LN2.5-IPSsevaWoidaR
iBd5.72,deziraloPenalP,lenaPtalF"4225-2DPFDleirbaG
iBd1.82,deziraloPenalP,hsidretemaid"42IRA25-2PSSleirbaG
iBd1.82,deziraloPlauD,hsidretemaid"42IRA25-2DSSleirbaG
iBd5.33,deziraloPenalP,hsidretemaid"84*A25-4PSSleirbaG
iBd5.33,deziraloPlauD,hsidretemaid"84*A25-4DSSleirbaG
.tnailpmocCCFtoneradna,ylnoASUehtedistuoesuroferasannetnahsid"84ehT*
500202LW
Table 2.3 - Recommended Antennas
The antennas shown in Table 2.3 are recommended for use with Link AX. With the exception
of the 4’dishes, all antennas have been tested with Link AX to verify compliance with applicable
FCC rules.
2.2.8 Power Requirements
Primary power supply
DC ±21 to ±56 V
AC 100 to 240V 50/60 Hz (with optional external power supply).
Power Consumption Maximum 17 Watts
2.2.9 Environmental Specifications
Outdoor Unit Operating Temperature Range: -30°C to +60°C
Storage Temperature Range: -40°C to +85°C
Altitude: 4,500 meters max.
Humidity: Outdoor, all-weather enclosure
2.2.10 Mechanical
Dimensions
ODU 310mm x 351mm x 73mm (HxWxD)
12.2”x 13.8”x 2.9”
Weight
ODU 5 kg
11 lbs

8
WaveNetLinkAXInstallationandOperationsManual
2.3 User Interfaces
The Link AX provides user interfaces for fused DC power connection, electrical grounding,
radio frequency (RF) antenna connection, ATM25 connection, configuration and RSSI output.
The following provides information on each interface.
Outdoor Unit
•Data/Power Cable - Siamesed CAT-5 ATM25 and power cables.
•RSSI - BNC type connector for RSSI measurement.
•Antenna (RF) Connector - N-type female connector used for connection with antenna.
Note: There is no N-Type RF connector used on ODUs with integral antennas.
•Main Power - The Link AX is designed to work from a power input of 21 to 56 VDC.
•Grounding Connector - The ODU is equipped with an M5 ground screw and associated
washers. This ground screw serves as the proper chassis-ground connection point for an
external ground source. The Link AX must be grounded in accordance with the electrical
codes, standards, and practices governing the local installation.
•Configuration Switch - Configuration of the Link AX is performed via a DIP switch on the
ODU. The 10-position DIP switch is accessible by removing the water-tight dust cap on
the ODU. Once exposed, each of the 10 switches can be manipulated using tool that is
provided with the mounting kit.
2.4 ODU Performance Monitoring
RSSI (Receive Signal Strength Indicator) - A voltage provided through a BNC connector on
the outside of the ODU. The RSSI port is used for antenna alignment during installation and
for periodic measurement of Receiver/Path performance. The RSSI voltage in relation to the
receive signal level ranges from -30 dBm to -90 dBm.

9
WaveNet Link AX Installation and Operations Manual
2.5 Theory of Operation
General Overview
The Link AX is a point to point Wireless ATM-25 Extender operating in the 5.3/5.7 GHz U-NII
band as authorized in rule sections 15.401 through 15.407. The unit is enclosed in a weather
proof outdoor enclosure and is intended to provide data links over distances up to 15 km. The
radio in the unit operates full duplex, transmitting and receiving data at the rate of 8.192 Mbps.
The radio is modulated using BPSK.
Circuit Description
The following circuit description is intended to explain the operation of the radio at the block
diagram level. This text is written with the idea that the reader has the block diagram readily
available, as it will aid in understanding the signal flow in the radio.
2.5.1 Link AX Transmitter
The physical interface to the radio consists of ATM-25 cells that are routed to ATM physical
interface (PHY) chip. The PHY chip stores the data cells, and then converts them into a
synchronous 8.448 Mbps data stream that is fed into the transmitter. To mark cell boundries,
a SYNC byte (01111110) is inserted at the beginning of every cell. Zero insertion circuitry,
inserts a zero after five consecutive ones, guaranteeing SYNC byte uniqueness while
transmiting the cell’s content.
The data is differentially encoded and scrambled before it is routed through the transmit
baseband filter to provide spectral shaping. The baseband filter is a five pole low pass filter.
After amplification, the baseband signal is fed to the modulator consisting of a doubly
balanced mixer. The modulator is running directly at the transmitter frequency of 5.775 GHz
±50 MHz. The local oscillator signal of the mixer is supplied from the frequency synthesizer
section, with the frequency dependant on the RF channel selected.
From the output of the modulator, the signal is amplified and then passed through a 150 MHz
wide bandpass filter to remove any local oscillator products from the output spectrum. After
filtering, the signal is passed through a series of amplifier and attenuator stages that are used
to control the output power level. With a combination of fixed and variable attenuation the
output power can be set to one of four different levels to accommodate different antennas
used with the product.
The power setting is maintained by an active ALC circuit that samples the transmitter output
power and then adjusts the variable attenuator to keep the output power constant over the
operating temperature of the unit. The power level is controlled to within +1/-2 dB of the set
point.
Following the attenuators the signal is fed through additional amplification to bring the output
level to a maximum of +14 dBm at the output of power amplifier. A lowpass matching section
follows the power amplifier to aid in filtering harmonics of the signal. After passing through the
duplexer, the power level at the antenna port is a maximum of +12 dBm.

10
WaveNetLinkAXInstallationandOperationsManual
Figure 2.2a - Outdoor Unit, Front View, External Antenna
Figure 2.2b - Outdoor Unit, Back View, External Antenna
WL293001
DIP Switch Access
Antenna Connection
(N Type, Female)
ODU
Ground Connection
Mounting
Studs
WL292002
Receive Signal Strength
Indicator (RSSI) (BNC Type,
Female)
Siamesed Category 5
ATM and Power cables
connections

11
WaveNet Link AX Installation and Operations Manual
ODU
Ground Connection
Mounting
Studs
WL291003
Receive Signal
Strength Indicator
(RSSI) (BNC Type,
Female)
Siamesed Category 5
ATM and Power Cables
Connections
DIP Switch Access
Figure 2.2c - Outdoor Unit, Front View, Integral Antenna
Figure 2.2d - Outdoor Unit, Back View, Integral Antenna
Outdoor RF unit
with integral Antenna
WL241008

12
WaveNetLinkAXInstallationandOperationsManual
2.5.2 Link AX Receiver
The receiver in theLink AX is a conventional dual conversion design with IF frequencies of
474.88 MHz and 70 MHz.
From the receive port of the duplexer, the low level input signal is passed through a low noise
preamplifier that provides 25 dB of gain. Following the preamplifier the signal is passed
through a 200 MHz wide bandpass filter to provide image rejection for the first mixer.
The signal is then mixed with the first LO to convert the signal to 474.88 MHz. Following further
amplification the signal is passed through a five pole, 20 MHz wide bandpass filter. This filter
provides image filtering for the second mixer, and also helps attenuate signals on the adjacent
receive channels. After filtering, the signal is further amplified and then passed through a
variable attenuator stage before it is applied to the second mixer.
The output of the second mixer is at 70 MHz. The 70 MHz IF stages provide additional gain
along with two sections of variable attenuation for the AGC function. The primary adjacent
channel filtering is also at 70 MHz where the signal is passed through a 12 MHz wide SAW filter.
The combination of filters provide a minimum of 47 dB of attenuation at the adjacent receive
channels (±10.24 MHz).
At the end of the 70 MHz IF chain the signal is fed into a quadrature demodulator. The carrier
recovery loop consists of a four quadrant multiplier that multiplies I and Q baseband signals
to create an error voltage. This error voltage is then amplified and fed back to the 70 MHz VCO.
This forms a phase locked loop that is locked to the received carrier frequency.
The 70 MHz output is also fed into a wide band logarithmic amplifier that provides a DC voltage
output proportional to the 70 MHz signal strength. The DC voltage is then integrated and fed
back to the variable attenuator stages to form an AGC control loop. This control loop keeps
the signal level at the input to the demodulator chip constant over the entire operating range
of the receiver.
Data recovery from the I baseband signal begins by passing the I signal through a slicer. The
output of the slicer is a digital signal that contains both data and clocking information. A clock
recovery circuit recovers receive timing information that is needed to clock the data through
the descrambler, and differential decoder.
This 8.448 Mb bit stream is then converted into ATM cells. The SYNC bytes and the inserted
zeros are stripped form the cells prior to their delivery to the ATM25 PHY. This method provides
worst case cell rate of 15645 cells per second (cps) and typical cell rates of approximately
19200 cps.