Training Module on MW radio engineering
Learning today……
Understanding Microwave link : applications, configuration, operating parameters, system calculations Line of Sight requirements and Antenna Heights Antenna Installation alignment and its parameters, safety and quality MW Link Installations and commissioning : standard practices : NEC’s approach Concluding : General site issues: questions & answers
excerpt from the Scientific American
July 1892
In the specification to one of his recent patents, Thomas A. Edison says: “I have discovered that if sufficient elevation be obtained to overcome the curvature of the earth’s surface and to reduce to the minimum the earth’s absorption, electric signaling between distant points can be carried on by induction without the use of wires.” MICROWAVE PATH ENGINEERING – OVER 110 YEARS AGO!
1
Basic characteristics
• Operates on a “Line-of-sight" principle • Use Two antennas aimed directly at one another • Transmit Digitally modulated Microwave Frequencies through free space from one terminal to another • Typically transmit simultaneously in both directions (Full Duplex)
Line of sight Point to Point MW link 400
300
200
100
0 .5
1 .0
1 .5
2 .0
2 .5
3 .0
3 .5
4 .0
4 .5
5 .0
D is ta n c e ( m ile s )
T y p ic a l P a th P r o file
Deployment and applications FWS (Point-to-Point Transport) and FWA (BWA, Access) Hops POP – Point of Presence
ClearBurst MB Point-to-Multipoint FWA (Fixed Wireless Access) Broadband Links
155 Mbit/s So net/SDH FWS (Fixed Wireless Sys tem) Hop
Nodal (Hub) Site CPE
CPE
CPE
PB X
CPE – Customer’s Premises Equipment:
- Sonet/SDH (PTP) - ATM Switch
- Frame Relay - Video
Conference
- LAN/IP - POTS
- Base Station - Sonet/ SDH
- T1/E1 - ISDN
FWS and FWA (BWA) Radio Hops Long Distance 2xT1/E1 Unlicensed Hop
Access Hops
Short Distance SONET/SDH Hop
Short Distance 4xT1/E1 Hops
OC-12 or STM-4 Fiber Ring X X
NMS system
Transport Hop Sonet/SDH NxOC-3 or NxSTM-1 Backbone FWS (Radio-Relay) Hop
GSM Network layout
Fiber and MW transmission media in GSM/CDMA Networks
FWS Microwave Applications PCS/Cellular Site Interconnection (North American Hierarchy)
1
z (N 8 GH
18 G Hz (
1) x DS
MTSO (MSC) - Switching Office BTS - Base Station BSC - Base Station Controller 23 GHz (OC-3)
DS3 )
38 G
BTS
Hz ( Nx
BTS
DS1 )
BTS
BSC (DS3 or OC-3NxO C-3 ) or 155 (Nx0 C
MTSO (MSC)
BTS -3) Self-Healing
Ring
BSC
Access and metro /transport networks
Core Network Topologies
Some Attributes of Digital Microwave Radios • •
Superior availability - route security (no cable cuts) Rapidly expandable and upgradeable, in-service if protected
•
High quality - no multihop “noise” addition
•
Rapid deployment over difficult terrain and into urban areas
•
Economical - no copper or fiberoptic cable deployment
•
Robust to fading and interference
•
Insensitive to antenna feeder system and long-delayed on-path echoes
•
Highly efficient data and broadband transport
•
Exacting in-service visibility of radio hop performance with NMS
•
Seamless interconnectivity to an ever-expanding digital transport (fiberoptics and other), PABX/MSC switch, and LAN/IP world.
Typical Electromagnetic spectrum M o b ile R a d io V H F T e le v is io n F M B r o a d c a s t R a d io S h o r tw a v e R a d io M o b ile R a d io F ib e r O p tic s A M B r o a d c a s t R a d io
V is ib le L ig h t
U H F T e le v is io n M ic r o w a v e s
1M H z
1000m (3 0 0 K H z )
10M H z
100m (3 M H z )
100 M H z
10m (3 0 M H z )
1G H z
1m (3 0 0 M H z )
10G H z
10cm (3 G H z )
100G H z
1cm (3 0 G H z )
10
1m m (3 0 0 G H z )
12
10
14
Transport and Access Bands Network Management Element Manager SNMP Interface
Capacity NxOC-3/STM-1 3xDS3/OC-3/STS-3 4xDS3, 4xE3/STM-1
1:N
Backbone Transport Broadband Wireless Access (FWA)
DS3 or 28 T1 E3 or 16 E1 16 T1
Backbone & Access
8 E1 4 T1/E1
Access
Unlicensed
2 T1/E1 T1/E1 8 6 Frequency Band: 2 Typical Path Lengths: >15-60mi/25-100km
11 13 10 18 37 42 GHz 23 26 7-15mi/12-25km 5-10mi/8-17km 1-5mi/2-8km
Example of capacity and frequency bands
CEPT PDH Hierarchy VF/data/LAN/IP and teleconferencing circuits 1 2. ..
1st Order
2.048 Mbit/s (30/31 Ch)
30/31*
PCM Channel Banks
E1
1 2 3 4
M2-8
8.448 Mbit/s (120 Ch)
2nd Order
E2
1 2 3 4
E3 M8-34 3rd Order
34.368 Mbit/s (480 Ch)
E4
*30 VF Channels with signaling channel or 31x64 kbit/s Data Channels (no signaling) E3 16 x 2.048 Mbit/s E1 Trunks
1 2. .. 16
M2-34 SkipMux mux Skip
1 2 3 4
M34-140 Radio MUX
140 Mbit/s (1920 Ch)
34 Mbit/s (480 Ch) PDH -Plesiochronous (asynchronous) Digital Hierarchy
CEPT Hierarchy is the international TDM digital standard everywhere except North America (USA, Canada), Taiwan, Korea and Japan.
TDM: CEPT PDH Hierarchy PDH - Plesiochronous Digital Hierarchy Designation
No. of E1 Trunks
Bit Rate (kbit/s)
Line Code
Voice Channel Equivalent
E0 E1 E2 E3 E4
30/31 = 1E1 1 4 16 64/63*
64 2,048 8,448 34,368 139,264
AMI HDB3 HDB3 HDB3 CMI
1 30 120 480 1920/1890*
CEPT PCM Analog-Digital PCM Quantizing Code is A-Law AMI, HDB3, & CMI codes are bipolar. Cable types: 120Ω Twisted Pair, 75Ω Coax (Length/type assigned for 6 dB maximum loss) Ref: ITU-T G.703, G.704
*63 E1 (1890 VF ch) are mapped in Synchronous Digital Hierarchy (SDH)
SDH Fundamentals: Rates Line Rate (Mbit/s)
SDH Signal
PDH Signal # E1 (2048 kbit/s)
VF
Transport
Radio or Fibre
2.048
VC - 12
1
30
34.368
VC - 3
16
480
51.84
Sub-STM-1*
21
630
139.264
VC - 4
64
1,920
155.52
STM - 1
63
1,890
622.08
STM - 4
252
7,560
2488.32
STM - 16
1,088
30,240
1:N Radio or Fibre
9953.28
STM - 64
4,032
120,960
Fibre
Ref.: ITU-R Rec. F.750-3 (1997)
SDH Synchronous Digital Hierarchy PDH Plesiochronous Digital Hierarchy *Sub-STM-1 RR-STM, STM-0 = 51 Mbit/s for Radio Relay)
SDH Fundamentals: Mux Pointer Processing SDH Synchronous Digital Hierarchy STM Synchronous Transport Module VC Virtual Container TU Tributary Unit TUG Tributary Unit Group AU Administration Unit AUG Administration Unit Group ATM Asynchronous Transport Mode RRRP Radio-Relay Reference Point NNI Network Node Interface Sub-STM-1 = RR-STM (52 Mbit/s for radio) = STM-0
Multiplexing Aligning Mapping
DS1
VC11
TU11
E1 DS1
VC12
TU12
DS2
VC2
x3 x1
TUG-2
x1
E3 DS3 x1
E4 ATM
TU-2
x4
VC3 x1
x1
VC3
x7
TU-3
TUG-3
x3
AU3
Sub-STM-1
x3
AUG
x1
VC4
Note: Bold indicates commonly available multiplexer interface
RRRP
AU4
x3
STM-N
NNI
Basic Building blocks of MW Link
Basic Building blocks of MW Link
Classical Design Waveguide
Waveguide
RF f [GHz]
Circulator, Filter (CBN)
Circulator, Filter (CBN)
RF = Radio frequency e.g. 7.5 GHz, 18.7 GHz
TX
RX
Transmitter
Receiver
IF = Intermediate frequency e.g. 140 MHz Modulator 16 - 128 QAM
Demodulator 16 - 128 QAM
BB = Baseband e.g. 155 Mbit/s Channel
Channel
Basic blocks of radio
IDU
Important to know…
IDU Functional blocks
ODU configuration
ODU Layout
• Outdoor Units (ODUs) are software configurable so that capacity upgrades can be made without climbing towers. • Indoor Units (IDUs) support capacities of 2/4E1, 4/8E1, 16E1, E3, 4/8DS-1, or DS3 and are frequency independent so that they can be used with any ODU of like capacity. – – – – – – –
Minimal Installation time Single coaxial cable connection between IDU and ODU Dual polarity DC input of (±21.6 to ±60 VDC) Adjustable transmit output power Frequency/channel setting via keypad or laptop PC Diagnostic loopbacks accessible via laptop PC Capacity to store 25 different channel plans
ODU functional modules
Link Block Diagram
Line Interfac e DEMUX
RX FPGA DEMUX Frame Frame Sync Private Link
TX MUX FPGA
DEMOD
TX IF PLL TX IF
310MHz
MOD
AGC
DEMOD Lock Low BER (>1e-9) AGC High BER (>1e-3) ODU Communication
Synth Up Conv. Osc Unlock Synth TX Offset Voltage Synth TX Main Loop Unlock Synth TX Offset Loop Unlock ALC
N le p rx o
LIU Input
MUX PLL
Near End RF Plug-in
N le p rx o
Near End SP
70MHz
DEMUX
MUX
DEMOD
PA
1778MH z
LNA
≈
RX Synth
Synth Up Conv. Osc Unlock Synth TX Offset Voltage Synth TX Main Loop Unlock 310MH Synth TX Offset Loop Unlock z
TX IF PLL TX IF
MOD
AGC
DEMOD Lock AGC RX FPGA Low BER (>1e-9) DEMUX Frame High BER (>1e-3) ODU Communication Frame Sync Private Link
ALC
N x le p ro
Line Interfac e
≈
Far End RF Plug-in
N le p rx o
LIU Input
PA
2158MH z IF LO RT 1848 PLL
Synth Rx Main Loop Unlock Synth Rx Offset Loop Unlock Synth Rx Offset Loop Voltage
Far End SP MUX PLL TX FPGA
TX Synth
70MH z
TX Synth
PA
2158MH z IF LO RT 1848 PLL 1778MH z
Synth Rx Main Loop Unlock Synth Rx Offset Loop Unlock Synth Rx Offset Loop Voltage
≈
PA
LNA
RX Synth
≈
Link Block Diagram
IDU-Indoor Unit
ODU Components
Signals on IF cable –IDU-ODU
Protection and Diversity Protection Schemes and Diversity Arrangements
Protection and Diversity The Need for Protection and Diversity
In the past, short traffic interruptions without traffic disconnect in microwave links were often acceptable to many private users.
Expectations changed with the digital microwave transport of MSC-cell site data, ATM, high speed data transfer, teleconferencing, imaging (medical, etc.), and such technology as the new digital mobile trunking systems.
Excessive numbers of short fade hits (circuit interruptions) are now barely tolerable, except in LAN/IP transport and access (millimeterwave) hops impacted by rain cells, long-term outages (traffic disconnects) are usually unacceptable.
Protection Schemes
Equipment degradation, failure: – 1+1, hot-standby or on-line modules …HS – 1:N, one standby for >2 modules ……..HS
Antenna system misalignment, failure: – Split transmitters + RCS* ………….HS+ST – Two-dish hybrid diversity** ….HD, SD+ FD – Self-healing ring (loop) architecture …..SR
*Reverse Channel Switch command from far end receivers ** If FD is permitted 87
Protection Types
1+1 hot-standby protection …………………….HS
1+1 on-line (paralleled elements) protection ...HS
1:N module protection ………………………….HS
1:N multiline protection …………….HS or HS+FD
Split transmitters with RCS* ……….……...HS+ST
Self-healing ring (or loop) architecture …….….SR
*Reverse Channel Switch command triggered by the dual failure (outage) of both far-end receivers
Protected & Diversity - Dual Antenna
1+0 Equipment Protection - "1+1 HSB" Configuration f1 f1a
f1` f1b
Station A PR
Ch. 1 (STM-1) RPS
Station B f1a
f1a
PR
MD TX
RX DM
MD TX
RX DM
OP
f1a
PR
f1b
C B N
C B N
10dB
f1a
OP
f1b
PR
DM RX
TX
MD
DM RX
TX
MD
f1b
OP
OP
f1b
10dB
RPS
Ch. 1 (STM-1)
1+0 Equipment Protection - Space Diversity f1 f1a
f1` f1b
Station A PR
Station B f1a
f1a
CBN
MD TX MD TX Ch. 1 (STM-1) RPS
OP
f1a
PR
f1b
C B N
DM RX DM RX OP
f1b
CBN
PR
RX DM RX DM f1a
C B N
OP
f1b
PR
TX
MD
TX
MD
f1b
OP
RPS
Ch. 1 (STM-1)
Typical spacing for SD
Frequency (GHz)
Minimum Spacing (m)
Ideal Spacing (m)
6,8
4,5
10
7
4,5
10
13
2,5
5
15
2,0
5
Microwave Radio Technology - Space Diversity
∆
∆
MD STM-1
DM +
TX RX RX
CBN Main CBN Div
CBN Main CBN Div
TX RX RX
MD STM-1
+ DM Length compensation
SD +HSB
Block Diagram - 2+0 Configuration with XPIC horizontal f1a Ch. 1 (STM-1)
MD
H
TX
140 MHz
CBN
DM RX
V
f1b
f1b horizontal
f1 OP1 OP2 f1
TX
RX DM PW
f1a Ch. 2 (STM-1)
f1b 2 Waveguide pro Station
TX
140 MHz
Ch. 1 (STM-1)
f1a
PW
MD
140 MHz
CBN f
MD
TX
CBN
CBN
DM RX vertical f1b
MD
140 MHz
Ch. 2 (STM-1)
RX DM f1a vertical
H
V
H
V
Clock synchronization Data compensation
Microwave Radio Technology - Frequency Diversity
f f1
f3
f3a
MD TX MD TX Channel 1
RPS
f3b
f1a
DM RX DM RX f1b
CBN
f1 f1a
f3 f3a
f1’ f1b
f3’ f3b
Hot-Standby & Space Diversity Hot Standby Terminal
Hot Standby Terminal with Space Diversity Receivers
*
* Power splitters in digital radios are always asymmetrical, not 3/3 dB as in analog radios, as data are errorlessly switched - not combined as are analog radio basebands. A 3/3 dB RF receiver splitter provides no protection benefits over the 1/7 dB splitter, and will lower fade margins 2 dB for 58% more outage time.
Splitter/Combiners Waveguide Coupler
Primary Path Insertion Loss
Standby Pass Insertion Loss
6 dB unequal coupler
1.6 dB
6.4 dB
3 dB equal splitter
3.5 dB
3.5 dB
RFD Configurations
1+0
2+0
1+1 HH
1+1 HS
Hybrid module for NEC radios
Ring (Loop) Protection (SR) Benefits of Ring Protection Cost-effective method of providing T1/E1 trunk redundancy in mixed radio, fiberoptics, span lines. Protects against Path, Site, and Equipment Failures with non-protected radio repeaters - lowers costs ~40%. Only protection from long-term periods of unavailability due to fiber cuts, power fades such as heavy rain at higher frequencies, infrastructure failures, etc. Operation, fault location, testing, and maintenance are simplified. A ring-closure microwave hop (perhaps longer or with degraded performance) or other T1/E1 trunk for ring closure (fiber, leased line) is necessary.
Component mountings- IF Module
The IF Module (IFM) consists of the following items: TX IF assembly RX IF assembly DC-DC converter
dB
dB
2 * Syn
IF 2 * Syn
dB DC
dB
dB
High integrated RF Module
RF Diplexer
dB
CPU
DC
Modulare ODU-Design
Antenna
Some more configurations.. Operation mode 1+0 with integrated antenna
Frequencies 7 up to 38 GHz
In some cases of interest in an offer because of the lowest price IDU STM-1
EOW DPU
f1
Power Supply Modulator Demodulator
coax. cable
ODU
H OP
V
Broad Band Filter
Operation mode 1+0 with separate antenna IDU 155-16/128 LS STM-1
EOW DPU
Power Supply Modulator Demodulator
f1
coax. cable
wave guide
ODU Broad Band Filter
H OP
V
Frequencies 7 up to 38 GHz
Operation mode 1+1 HSB with integrated antenna Frequencies 7 up to 38 GHz Master-IDU EOW DPU
Power Supply Modulator Demodulator
coax. cable
f1
ODU
1,3 dB H BK
Slave-IDU EOW DPU
Power Supply Modulator Demodulator
Coupler
ODU
6,3 dB
V
Operation mode 1+1 HSB with integrated antenna Frequencies 7 up to 38 GHz Master-IDU EOW DPU
Power Supply Modulator Demodulator
coax. cable
f1
ODU
1,3 dB H BK
Slave-IDU EOW DPU
Power Supply Modulator Demodulator
Coupler
ODU
6,3 dB
V
Operation mode 4+0 or 2x(1+1) dual polarized CCDP with XPIC Frequencies 7 up to 38 GHz
4 x IDU 155-16/128 LS EOW
STM-1
DPU
Power Supply Modulator Demodulator
ODU f1
Waveguide
f3
H
EOW
STM-1
DPU
Power Supply Modulator
Coupler
ODU
OMT
OP1
OP2
OP3
OP4
f1
f3
V
Demodulator
ODU LX – Adjacent Channels ODU S – 1 Ch. to be left EOW
STM-1
DPU
Power Supply Modulator
ODU
Demodulator
Wave guide
EOW
STM-1
DPU
Power Supply Modulator Demodulator
Coupler
ODU
Operation mode 4+0, coupler version in dual polarized CAP 4 x IDU EOW
STM-1
DPU
Power Supply Modulator Demodulator
Frequencies 7 up to 38 GHz ODU f3
f1
Waveguide H
OP2
OP1
EOW
STM-1
DPU
EOW
STM-1
DPU
Power Supply Modulator
Coupler
ODU
OMT
STM-1
DPU
OP4
f2
f4
V
Demodulator
Power Supply Modulator Demodulator
ODU Wave guide
EOW
OP3
Power Supply Modulator Demodulator
Coupler
ODU
Frequency Patterns - Transmission via 2 Polarizations Orthomode transducer (OMT) f1a
V: vertical
1.TX Polarization f1 MD
90°
CBN
DM RX f1b
H horizontal
f1a
2.TX Polarization f1 MD CBN
DM RX
Waveguide H H
f1b Waveguide V
H
V
V
Operational parameters and system planning
Microwave Frequency Required Necessary Antenna Gain Maximum Distance between terminals Receive Signal Level Margin Link availability
Understanding operating parameters
Understanding operating parameters
Understanding Threshold for receivers
Terms of Microwave Radio Technology - System Overview
TX
CBN waveguide
CBN waveguide
Output power
Max. power e.g. +31 dBm [1.25 W]
RX
Input power System attenuation (e.g. 71.7 dB)
Antenna CBN waveguide gain e.g. e.g. 41.4 dB 5.3 dB
Antenna CBN Free space attenuation e.g. 143.9 dB gain waveguide (Distance d = 50 km) e.g. e.g. (Frequency: f = 7.5 GHz) 41.4 dB 5.3 dB
System gain
Fading margin
a = 92.4 + 20 ⋅ log( d[km]⋅ f[GHz]) 0
min. power e.g. -73 dBm [50 pW]
System Gain, Net Path Loss EIRP = P0 - Lf + Ga (FCC/ETSI Constraints) Ga FREE SPACE LOSS (NO FADE)
Lf
Transmitter Output Interface
P0 3
2
1
Repeater Station
NET PATH LOSS (NPL) SYSTEM GAIN (to 10-3 BER or Top of LOF) Bay Antenna Port
RSL IN 1
Top of Bay Antenna Port
SYSTEM GAIN. dB
NPL - NET PATH LOSS. dB
XMTR Power Out - RCVR RSL In (for 10-3 BER) at the Antenna Ports. Typically 100 dB
Waveguide In Site A to Waveguide Out at Site B. Typically 60 dB (Excluding Fade Activity)
2
3
Receiver Input Interface
Terminal Station RECEIVER RSL INPUT. dB RSL = XMTR Power Out - NPL THERMAL FADE MARGIN. dB TFM = System Gain - NPL
Receive signal level calculation RSL(dBm) = Tx power(dBm) + Tx antenna gain(dBi) Free Space Loss(dB) – Branching Loss – Feeder cable loss + Rcv antenna gain (dBi) where Free Space Loss(dB) = 32.4 + 20logF +20logD For example: where: DPath is Kms, Given: Distance F of is 10MHz Kms, Radio Frequency is 7 GHz, Tx Power is 20 dBm, dBi
and
Antenna Gain(both sides) is 38
•Free Space Loss = 32.4+20log(10)+20log(7000) = 32.4+20+76.90 = 129.30 dB •RSL(dBm) = 20 dBm + 38 dBi – 129.3 dB + 38 dBi = - 33.3 dBm
Receive signal level margin
• Directly determines the availability of the link by providing threshold “cushion” against signal fade due to environmental conditions, i.e. rain, snow, hail, etc. • Rain data for geographic location is needed to calculate availability once RSL margin is known.
Technology Technical Topics that define Digital Radio Hops
System Gain, Net Path Loss RF Signal, Noise, and Interference Levels Static and Dynamic Thresholds Microwave Spectral Efficiency QAM, QPSK Modulation DSSS, OFDM/COFDM Signal Spreading Microwave Spectrum Calculations Co-Channel Dual Polarization (CCDP) Latency ATPC and DTPC Frequency Bands, Interference, Terrain Scatter Frequency Band Selection
ATPC and DTPC DTPC – Dynamic Transmit Power Control (TRuepoint, Galaxy 23) ATPC – Automatic Transmit Power Control (all other radios) ATPC or DTPC, features that reduce transmit powers except with farend receiver alarms during deep fades, are occasionally assigned to some microwave links for one of the following reasons: Prevents receiver front-end overload in higher frequency links assigned high rain fade margins Complies with FCC (and other) EIRP constraints in short hops, <17 km in the 6 GHz bands and <5 km at 10 and 11 GHz, Prevents receiver overload in shorter 6, 10, and 11 GHz paths requiring large antennas in frequency-congested areas Reduces interference levels at hubbing sites and into adjacent links in frequency-congested areas.
ATPC
ATPC
DTPC/ATPC Transmit and Receive RF Levels During 1-Hour Fade Activity in a High Fade Margin (60dB) 23 GHz DTPC Link. RSL follows fades below the “setting point”, -45 dBm in this example -10
Fade Depth, RSL w/o DTPC
-20 -30 -40 -50 -60
-20
10-6 BER Receiver Overload
Error-free
-30 -40 -50
DTPC RSL Setting Point -45 dBm
RSL w/DTPC
-60
No Outage
+20 +10
Transmitter Output
0
-70
-10
Outage Threshold -80
-70 0
10
20 30 40 1-Hour of Rain Fade Activity, Minutes
50
60
Transmitter Output Power, dBm
Fade Depth, dB
-10
Receive Signal Level, dBm
0
RSL
Fading
Stopped Fading
10
–6
ATPC Off
Th + 15/18 dB
7/10 dB 7/10 dB BER = 10
15/18 dB
-11
Un-Fading BER = 10
-6
ATPC On
Time
ATPC
Important to know…
Useful Formulas Supplementing the Outage Model For
English (ft, mi, GHz, dB)
Metric (m, km, GHz, dB)
96.6 + 20 log f + 20 log D
92.4 + 20 log f + 20 log D
0.67 d1d2/k
d1d2/12.7k
Path Loss Earth’s curvature F1 radius
72.1 (d1d2/f D)0.5
17.3 (d1d2/f D)0.5
Fn radius
F1 (n)0.5
F1 (n)0.5
Dish gain (55% efficiency)
7.5 + 20 log f + 20 log d
17.8 + 20 log f + 20 log d
66/fd
20/fd
1200 D/f h(t)
127D/f h(t)
Fn /2f
Fn/2f
Dish BW, degrees Div. dish separation Multipath delay, nsec
NOTATION:
f
= frequency, GHz
D = path length
k = k-factor (4/3rds, etc.)
d1, d2= distances (d1 + d2 = D)
h(t) = Tx dish height above
n = Fresnel zone number
the reflection plane
F1 = 1st Fresnel zone radius d = dish diameter
Important to know… Site Details
Address, Lat-Long, Azimuth wrt North, equipment layout
Access /permission/approach road
Link Budget
Expected Receive level/ Tx Planner/Operator Fade Margin Frequency of operations and Tx power;
Cabling details
Type of antenna, Height of antenna, Polarization
LOS cleared
External alarm termination details/color code
NMS IP address/DCN planning /cabling/router/convert er
Traffic E1/STM1 termination /Through
EOW, Auxiliary channels/Sideway E1
Understanding Frequency plan Frequency Sub Duplex [MHz] Band [GHz] 10
350
10224 10574
350
10252 10602
Capacity
BW [MHz] / Channel Raster
16 E1
28
8 E1
14
4 E1
7
2 E1
3.5
25 MHz Channel Filter Bandwidth
5.5 MHz
14 MHz
16 E1 CAPACITY
5.5 MHz
Fade Margin Degradations Effective diversity arrangements lessen the impact of otherwise unacceptable conditions:
Co- and adjacent-channel interference
Low fade margins
Antenna k-factor decoupling
Antenna misalignments
Dispersive (spectrum-distorting) fades
Ducting, defocusing, and obstruction fades
EMI and other environmental effects
