Adtran TRC4206 Users Guide

TRACER 4206

System Manual

12804206L1A TRACER 4206 System (Plan A) 12804206L1B TRACER 4206 System (Plan B)

612804206L1-1A September 2002

Trademarks

Any brand names and product names included in this manua l are trademarks, registered trade marks, or trade names of their respective holders.

To the Holder of the Manual

The contents of t his manual are cu rrent as of the date of publi catio n. ADTRAN reser ves the right t o change the contents without pri or notice.

In no event will ADTRAN be liable for any special, incide ntal, or consequential damages or for commercial losses even if ADTRAN has been advised thereof as a result of issue of this publication.

901 Explorer Boulevard

P.O. Box 140000

Huntsville, AL 35814-4000

Phone: (256) 963-8000

Printed in U.S.A.

About this Manual

This manual provides a complete description of the TRACER 4206 system and system software. The purpose of this manual is to provide the technic ian, system administrator, and manager with general and specific information related to the planning, insta llation, operation, and maintenance of the TRACER 4206. This manual is arranged so that needed information can be quickly and easily found. The following is an overview of the cont ents.

Section 1 System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Provides managers with an overview of the TRACER 4206 system.

Section 2 Microwave Path Engineering Basics . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Explains the basics of analyz ing a wireless microwave link, or path. The significant parameters are defin ed, and seve ral recommendations are offered.

Section 3 Engineering Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Provides information to a ssist network designers with incorporating the TRACER 4206 system into their networks.

Section 4 Network Turnup Procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Provides step-by- step in struc tions on how to in sta ll the TRACER 4206 unit , dete rmine th e parameters for the syst em, install the network and option modules, and power up the system.

Section 5 User Interface Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Explains the termina l interface and provides a description for each of the menus availabl e for the TRACER 4206 system.

Section 6 Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Provides helpful inf ormation for troubleshooting common config uration problems for the TRACER 4206 system.

Revision History

This is the first issue of this manual.

Notes provide additional useful informat ion.

Cautions signify information that could prevent service interruption.

Warnings provide information that could prevent damage to the equipment or endangerment to human life.

Safety Instructions

When using your telephone equipment , ple ase follow these basic safety precaut ions to reduce the risk of fire, electrical shock, or personal injury:

1. Do not use this product near water, such as a bathtub, wash bowl, kitchen sink, laundry tub, in a wet basement, or near a swimming pool.

2. Avoid using a telephone (other than a cordless-type) during an electrical storm. There is a remote risk of shock from lightning.

3. Do not use the telephone to report a gas leak in the vicinity of the leak.

4. Use only the power cord , power supply, an d/or ba tteries indicate d in the manua l. Do not disp ose of batteries in a fire. They may explode . Chec k with local codes for special disposal instruc tions.

Save These Important Safety Instructions

Federal Communications Commission Radio Frequency Interference Statement

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 pro vide 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 frequencies. Operation of this equipment in a residential area is likely to cause harmful interference in which c ase the user will be required to correct the interference at his own expense.

Shielded cables must be used with this unit to e nsure compliance with Class A FCC limits.

Changes or modificati ons to this unit not e xpressly appr ov ed by the par ty responsible for compliance could void the user’s authority to operate the equipment .

Radio Frequency Interface Statement

This equipment ha s 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 genera tes, uses, and can radiate radio frequen cy energy. If not installed and used in accordance with the instructi ons, it may cause interference to radio communications.

The limits are des igned to provid e reaso nable prot ecti on again st such int erferenc e in a re sidenti al situatio n. However, ther e is no guarante e that inte rf erence will not occur in a partic ular insta ll ation. If this equi pment does cause interferenc e to radio or tele vision rec eption, 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 betw een the equip me n t and the aff ected rece iver.

• Connect the equipment and the affected receiver to power outlets on separate circuits.

• Consult the dealer or an experie nced r adio/TV technician for help.

Changes or modificati ons not expre ssly approved by ADTRAN coul d void th e user’s authority to operate the equi pment.

FCC Output Power Restrictions

The FCC does not require licensing to implement this device. License-free operation in the industrial, scientific, and medical band is documented in FCC Rules Part 15.247. It is the responsibility of the individuals desi gning and implementing the radio system to assure compliance with any pertinent FCC Rules and Regulations. This device must be professionally installed.

Exposure to Ra dio Frequ ency Fi elds

The TRACER 4206 is designed to operate at 5.8 GHz with 100 mW maximum transmit power.

This level of RF energy is below the Maximum Permissi ble Exposure (MPE) leve ls specified in FCC OET 65:97-01. The installation of high gain antenna equipment in the system configuration may create the opportunity for expos ure to levels higher than recommended for the general population at a distance less than 15 feet (4 .6 meter) from t he center of the antenn a. The following precautions must be taken during installation of this equ ipment:

• The installed a ntenna m ust no t be loca ted in a manner t hat a llows expo sure o f the ge neral pop ulation to the direct beam path of the antenna at a distance less than 15 feet (4.6 meters). Install ation on towers, masts, or rooftops not accessible to the general population is recommended; or

• Mount the antenna in a manner that prevent s any perso nnel from entering the area within 15 feet (4.6 meter) from the fron t of the anten na.

• It is recommended that the installer place radio frequency hazard warnings signs on the barrier that prevents acce ss to the anten n a.

• Prior to installing the antenna to the TRACER 4206 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 coaxi al 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 ant enna.

These simple precautio ns must be taken to pr event general population and installation personnel from exposure to RF energy in excess of specified MPE levels.

Customer Service, Product Support Information, and Training

ADTRAN will repair and return this produ ct if within five years from the date of shipment the product does not meet its published specif ication or the product fails while in servic e.

A return material author ization (RMA) is required prior to returning equipment to ADTRAN. For service, RMA requests, training, or more inform ation, use the contact information giv en below.

Repair and Return

If you determine that a repair is needed, please contact our Customer and Product Servi ce (CAPS) department to have an RMA number issued. CAPS should also be contacted to obtain information regarding equipment curr e ntly in house or possible fees associated with repair.

CAPS Department (256) 963-8722

Identify the RM A num b er clearl y on the pac kag e (b elo w addre ss) , and retur n to th e foll ow ing ad d ress :

ADTRAN Customer and Product Service 901 Explorer Blvd. (East Tower) Huntsville, Alabama 35806

RMA # _____________

Pre-Sales Inquiries and Applications Support

Your reseller should serve as the first point of contact for support. If additi ona l pre-sale s support is needed, the ADTRAN Support web site provides a variety of support services such as a searchable knowledge base, latest product documentation, application br ie fs, case studies, and a link to submit a question to an Applications Engineer. All of this, and more, is available at:

http://support.adtran.com

When needed, further pre-sales assistance is available by calling our Applications Engineering Department.

Applications Engineering (800) 615-1176

Post-Sale Support

Your reseller should serve as the first point of contact for support. If additional support is neede d, the ADTRAN Support web site provides a variety of suppo rt services such as a searchable knowledge base, updated firmware releases, latest product documentation, service request ticket genera tion and trouble-shooting tools. All of this, and more, is available at:

http://support.adtran.com

When needed, further post-s ales assistance is available by calling our Technical Support Center. Please have your unit serial number available when you call.

Technical Support (888) 4ADTRAN

Installation and Mainte na n c e Su pport

The ADTRAN Custom Extended Services (ACES) progra m offers multiple types and levels of ins tallation and maintenance servic es which allow you to choose the kind of assistance you need. This support is available at:

http://www.adtran.com/aces

For questions, call the ACES Help Desk.

ACES Help Desk (888) 874-ACES (2237)

Training

The Enterprise Ne twork (EN) Technical Trai ning Depar tment offe rs tra ining on our most popula r produc ts. These courses include overviews on product features and functions while covering applications of ADTRAN's product lines. ADTRAN provides a variety of training options, including customized training and courses taught at our facilit ies or at your site. For more informati on about training, please contact your T erritory Manager or the Enterprise Training Coordinator.

Training Phone (800) 615-1176, ext. 7500 Training Fax (256) 963-6700 Training Email training@adtran.com

SYSTEM DESCRIPTION

This section of ADTRAN’s TRACER 4206 System manual is designed for use by network engineer s, planners, and designers for overview information about the TRACER 4206.

It contains general inf ormation and describes physical and operat ional concepts, network relationships, provisioning, test ing, alarm st atus, and sys tem monitor ing. This se ction s hould be use d in conjunc tion with Section 3, Engineering Guidelines, of the system manual.

CONTENTS

System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2

Features and Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Configuration and Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Operational . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Section 1, System Description TRACER 4206 System Manua l

1. SYSTEM O VERVIEW

The ADTRAN TRACER® 4206 wireless sys tem provi des four ind epende nt T1 c ircu its ove r a wir eles s link for up to 30 miles (line-of-sight path required). As authorized under Part 15.247 of the FCC Rules, the TRACER 4206 operates license-free in the 5.8 GHz unlicensed Industrial, Scientific, and Medical (ISM) band, requiring no FCC licensing of end users.

For configuration and testing, the TRACER 4206 provides the capability to control the remote TRACER 4206 through a separate maintenance channel. The TRACER 4206 has several built-in test capabilities including remote loopba ck. Complete configuration and performance dat a is available through menus accessed using a standard RS-232 terminal interface.

2. FEATURES AND BENEFITS

The following is a brief list of TRACER 4206 features and benefits:

Configuration and Management

• Easy to use VT100 control port (RS-232 inte rface) for configuration and monitoring

• Remote configuration

Operational

• Four Transparent T1 transmi ssion, over digital microwave link

• No license required per FCC Rules Part 15.247

• Frequency: 5.734 to 5.833 GHz

• Point-to-point, up to 30 miles

• 1-U high unit for easy rack-mounting

MICROWAVE PATH ENGINEERING BASICS

CONTENTS

Line-of-site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Decibels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Receiver Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Antenna Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Path Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Antenna Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Antenna Beam Patterns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Fresnel Zones, Earth Curvature, & Antenna Heights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Coaxial Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Receiver Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Fade Margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Path Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

FIGURES

Figu r e 1 . Exam p le Micr o wave Path with Pa r a meter s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 2. Typical Antenna B eam Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

TABLES

Table 1. Antenna Gain for Given Dish Diameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 2. Path Loss for Given Path Lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Table 3. Minimum Antenna Height for Given Path Lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table 4. Typical Coaxial Loss for Common Cable Types, per 100 ft . . . . . . . . . . . . . . . . . . . . . . 20

Section 2, Microwave Path Engineering Basics TRACER 4206 System Manual

1. LINE-OF-SITE

The TRACER 4206 system is designed for operation in the 5725 MHz to 5850 MHz unlicensed Industrial, Scientific, and Medical (ISM) frequency band. Radio wave propagation in this band exhibits microwave characteristics, which are ideally suited for point- to-point, line-of-sight communications. Line-of-sight essentially requires that the transmitting antenna and receiving antenna are able to “see” each other, and that the straight-line path between the two antennas is free of any obstructions, such as buildings, trees, mountains, and, in longer paths, even the curvature of the earth.

Point-to-Point Wireless communication from a single site to another

individual site. Contrast with point-to-multipoint

Line-of-Sight An unobstructed, direct path exists between the

transmitting and the receiving antennas.

2. DECIBELS

The received signal power equation is often expressed in a decibel (dB) format, which turns the power multiplication a nd division operations into addition and subtraction operations. In general, any quantity can be expressed in decibels. If the quantity (x) is a power level, the decibel equivalent is de fi ned as

If the quantity x is referenced to a milliwatt (mW), then the decibel-milliwatt (dBm) is used instead of a generic decibel.

dBm

10 log10x()⋅=

10 log

⋅=



------------ -



1mW

(dB)

(dBm)

3. RECEIVER POWER

The radio frequenc y (RF) signal power that is a vailable at the input t o the receiving TRACER 420 6 system is the next parameter of inter est in analyzing a wireless path. The TRACER 4206 has a maximum output power level of 100 mW, which is e quivalent to 20 dBm. This output signa l will be attenuated and distorted by various factors, all of which will degrade the original signal and affect the signal strength and quality as sensed by the receiving unit. A simplified power budget analysis is beneficia l to perform after verifying a suitable line-o f-sight path to determine if the microwave path is suit able, even for ideal, non-distorte d signals.

The equation relatin g receive d signal power to the other microwave parameters is

PTGTG

--------------------------4π()2d2L

(watts, W)

TRACER 4206 System Manual Section 2, Microwave Path Engineering Basics

where the variables in the equation are defined as

received p ow er (Watts) transmitted power (100 mW (max) for TRACER 4206 - adjustable) transmit antenna gain receive ant enn a g ain

λ carrier wavelength (c / ƒ) (meters) d pat h dist ance (meters) L other losses (RF coaxial cable, etc.)

The transmitted power is limited for the 5.8 GHz ISM band to 1W or 30 dBm. The actual transmit and receive antenna gain values are strictly dependent upon the physical characteristics of the antenna s installed for each link. Typical gains are between 20 and 40 dB. For example, a 4 foot diameter Parabolic dish has 34.2 dB of gain at 5.8 GHz. The carrier wavelengt h is the physical wavelength of the main RF carrier being used for communic ation, and is usually approximated at the center frequency of the band, which is 5787.5 MHz. This gives a wavelength of 5.18 cm.

The path distance is simply the physical distance between the transmit and receive antennas. For the TRACER 4206 these distances can range up to 30 miles. The final parameter L incorporates all other signal power losses in the microwave link, most of which are caused by antenna feed.

4. ANTENNA GAIN

Best performance will result from the use of a parabolic dish antenna. Antenna gain is determined by the size of the dish, with typical features detailed below. Dish manufacturers will be able to supply gains for other types of antennas.

Table 1. Antenna Gain for Given Dish Diameters

Dish Diameter

(in feet)

2 28.5 4 34.2 6 37.5

8 40.7 10 42.5 12 44.2

Gain

(in dBi)

Section 2, Microwave Path Engineering Basics TRACER 4206 System Manual

5. PATH LOSS

The expression

4πd



where

f carrier frequency (Hz)

λ carrier wavelength (c / f) (meters) d pat h dist ance (meters) c speed of light, free-space (meters)

is called the path loss, and increases rapidly as either path length increases or carrier wavelength decreases (which happens as the carrier fre quency increases). So, longer microwave paths will naturally experience more path loss than shorter paths. Likewise, higher frequency microwa ve communic ation will experience more path loss than lower frequenc y microwave communication.

Table 2 on page 16, tabulates path loss values for various path lengths for the TRACER 4206 system. Values not listed in the table can be interpolated from those listed.

--------- -



Table 2. Path Loss for Given Path Lengths

Path Length

4πdf



----------- -



(miles)

1 112

2 118

3 121

4 124

5 126 10 132 15 135 20 138 25 140 30 141 35 143

(dB)

Path Loss

(dB)

When using decibel notation, the received power equation becomes

4πdf



PTGTGRL– 20 · log

PTGTGRL– LP–++=

–++

----------- -



(dBm)

TRACER 4206 System Manual Section 2, Microwave Path Engineering Basics

Where, in the second equation the path loss has been lumped into a single quantity, LP, as discussed previously. When using decibel notation, it is necessary that all quantities are individually converted to

decibels prior to performing addition and subtraction.

When d is expressed in miles and f in GHz, the path loss expression in decibel s becomes

96.6 20 log10d() 20·log+

f()⋅+=

(dB)

Figure 1 illustrate s a wireless link containing all of the parameter s previously discussed.

d, L

Figure 1. Example Microwave Path with Parameters

6. ANTENNA ALIGNMENT

With line-of-sight microwave communications, optimum system performance requires that the transmitting a nd receivi ng a ntennas are proper ly aligne d. This will ensure maxi mum recei ved signal p ower at each receiver. Antenna alignment must be achieved in both azimuth (along a horizontal plane) and elevation (along a vertical plane). A received signal strength indicator (RSSI) is used to aid the equipment installer in deter mining when alignment is maximized, by simply ensuring maximum RSSI. The RSSI indicator for the TRACER 4206 system is provi ded through the VT100 terminal menus accessed through the RS-232 inter face, and is present ed as a series of bars indicating signal str ength. More bars means mo re RSSI, which ensures more received signa l strength and better link performance.

If the local system has acquire d a useful signal from the remote system, then the remote TRACER 4206 RSSI can also be viewed from the local TRACER 4206 VT100 terminal menu interface.

An RSSI T est point is also provided on the front panel. The vol tage (relative to the gnd test point) present on this test point represe nts a relative signal level of receive stre ngth from the far end. The voltage at this test point can vary from approxi matly 0 to greater than 4 Volts DC, with 0 Volts corresponding to no signal and 4 Volts or better to full signal strength.

Antenna Beam Patterns

Directly related to the subject of antenna alignment is the topic of antenna beam patterns. Antennas being used with the TRACER 4206 system will have a particula r beam shape determined in part by the physical construction and geometr y of the ant enna. The antenna beam patterns are characterized by a dominant main lobe, which is the preferred lobe to use for poi nt-to-point communications, and several side lobes, as

Section 2, Microwave Path Engineering Basics TRACER 4206 System Manual

shown in Figure 2 on page 18. The antenna alignm ent step to set ting up a microwave link is in f act steer ing the main lobes of both a ntennas until the main lobe of one transmitter is center ed on the receiving element of the receiving antenna.

main lobe

side lobes

Figure 2. Typical Antenna Beam Pattern

Antennas are also designed to radiate RF energy efficiently for a specific range of frequencies. Please consult the data shee t for your parti cular ante nna make and model to ensur e that it is specified to ope rat e in the 5725 MHz to 5850 MHz frequency band.

Fresnel Zones, Earth Curvature, & Antenna Heights

The Fresnel zones correspond to regions in the microwave path where reflections of the intended signal occur and combine in both constructive and destructive manners with the main signal, thereby either enhancing or reducing the net power at the receiver.

In general, the odd numbered Fresnel zo nes (1, 3, 5, ...) add constructively at the receive r, while the even numbered Fresnel zones (2, 4, 6, ... ) add destructively at the receiver.

The first Fres nel z one corresp onds to the main lobe, and must b e at le ast 60% fr ee of p hysical obstr uctions for the path calculations to be vali d. Since the main lobe contains the vast majority of the micr owave energ y, this zone is typically used to determine proper antenna heights when placing antennas on towers or buildings.

The curvature of t he Earth be comes a le git imate obst ructi on for pa th length s of 7 mi les or gr eater, and must also be accounted for when determining minimum antenna heights.

The aggregate expression f or minimum antenna height that incorporates bot h the 60% first Fresnel zone and the Earth curvature is given by

h 72.1

---- - 0.125d

(feet)

where f is in GHz and d is in miles. Table 3 tabulates minimum antenna heights for given path lengths.

TRACER 4206 System Manual Section 2, Microwave Path Engineering Basics

Table 3. Minimu m An t enna Height for Gi v en P at h Lengths

Path Length

(miles)

2 22 4 32 6 41

8 50 10 60 14 81 16 92 18 104 20 117 22 131 24 145 26 161 28 177 30 194 32 213 34 232 36 252

Min. Antenna Height

(ft)

7. COAXIAL CABLE

Coaxial cable will be re quire d to at tach the TRACER 4206 to t he ant enna. The length of the cabl e will var y from a few feet to several feet, depending upon your application and the proximity of the TRACER 4206 to the antenna.

Various grades of coaxial cable will work suffic iently well for connecting the TRACER 4206 unit to the antenna. A low-loss coaxial cable is suggested to minimize cable losses. One end of the cable will require an N-type male connector (plug) to mate with the TRACER 4206 unit. The other end of the coax will require a con nector com patible wit h the antenna chose n for the insta llati on, which is usually also a n N-type male connector (plug). Additionally, it is recommended that both connectors on the coaxial cable be weatherproofed from the elemen ts to prevent corrosion and electrical shor ting.

T able 3 gives typical loss figures for some of the more common coaxial cable types, per 100 feet.

Section 2, Microwave Path Engineering Basics TRACER 4206 System Manual

Table 4. Typical Coaxial Loss for Common Cable Types, per 100 ft

Cable Type Cable Loss (dB/ft)

RG-213, RG-214, RG-293

1/4” Coax 3/8” Coax 1/2” Coax 5/8” Coax

5.8 GHz Elliptical Waveguide

11.36

9.65

6.49

4.90

1.23

In certain areas whe r e lightning strikes are frequent, a lightning arre stor should be installed directly on the antenna coax. This will help protect the RF electronics in the downstream path from damaging voltages and currents, including the TRACER 4206 unit.

8. RECEIVER SENSITIVITY

Receiver sensitivity is a value expressed in decibels referenced to one milliwatt (dBm) that corresponds to the minimum amount of signal power needed at the receiver to achieve a given bit error rate (BER). Receiver sensitivity is usually a negative number of decibels, and as such smaller receiver sensitivity is better for a given BER. Several fact ors affect receiver sensitivity, including the data bandwidth of the wireless link, and the amount of additional signal degradation intr oduced in the receiver electronics . The

receiver sensitivity of the TRACER 4206 is -89 dBm at 10 for frequenc y agil ity, should an interfe rer b e ne arby.

-6

bit error rate. Three band plans are provided

9. FADE MARGIN

Fade margin is a val ue indicating the amount of extra si gnal power available to the receiver to operate at a maximum bit error rat e (BER). Higher levels of fade margin are better, and will protect th e viability of the microwave link against signa l fading. For most applications, 20 to 30 dB of fade margin should ensure a reliable link. Fade margin is simply the differenc e between the available signal power at the receiv er and the receiver sensit ivity, discussed previously:

FPRP

– PRGTGRL– LP– P

sens

–++==

sens

(dB)

10. PATH AVAILABILITY

The path availability of a wireless link is a metric that expresses the fractional amount of time a link is available over some fixe d a mount of time, and depends on several facto rs. Path availability is expr es sed as

A 12.510

6–

×()abfd310

F 10⁄–

()–[]100%×=

(dB)

+ 46 hidden pages

Adtran TRC4206 Users Guide

Specifications and Main Features

Frequently Asked Questions

User Manual

SYSTEM DESCRIPTION

1. SYSTEM O VERVIEW

2. FEATURES AND BENEFITS

Configuration and Management

Operational

MICROWAVE PATH ENGINEERING BASICS

1. LINE-OF-SITE

2. DECIBELS

3. RECEIVER POWER

4. ANTENNA GAIN

5. PATH LOSS

6. ANTENNA ALIGNMENT

Antenna Beam Patterns

Fresnel Zones, Earth Curvature, & Antenna Heights

7. COAXIAL CABLE

8. RECEIVER SENSITIVITY

9. FADE MARGIN

10. PATH AVAILABILITY