MDRS MD RS15 155E 5E – Op Oper erat atio ion n Modul Module e 1 - Introd Introduct uctio ion n
Microwave Radio Technology
STM-1
STM-1 ♦ ♦ ♦ ♦
STM-1 2 Mbit/s
Free-space propagation of electromagnetic waves Line of sight connection Frequency range • 3 to 38 GHz Short-haul and long-haul systems STM-1 2 Mbit/s
Microwave Radio Technology
Waveguide Long-haul system Short-haul system ♦ Range ♦ Range • 15 to 40 km • up to approx. 20 km (w/o diversity) ♦ Frequency range >80 km km • 40 - >80 • 15 to 38 GHz (with diversity) ♦ Transmission capacity ♦ Frequency range • 2 to 622 Mbit/s • 3 to 13 GHz ♦ Transmission capacity • 2 to 622 Mbit/s
Outdoor Unit
Coaxial cable
Microwave Micro wave Radio Techn Technology ology - System Design Designation ations s
Long-haul systems 155/7500 500 - 64 QAM QAM ♦ MDRS 155/7 microwave radio radio - 7R design design • SDH microwave 155/6800 800 - 64 MLQAM MLQAM E ♦ MDRS 155/6 155/13000 - 128 MLQAM E ♦ MDRS 155/13000 microwave radio radio - ETSI design design • SDH microwave • Short name: MDRS 155 E ♦ MDRS 2-34/ 2-34/7400 7400 - 16 QAM QAM 2x34/7400 7400 - 64 QAM QAM ♦ MDRS 2x34/ microwave radio radio - 7R design design • PDH microwave
Short-haul systems 155/1870 8700 0 - 16 QAM QAM N ♦ MDRS 155/1 microwave radio radio - "NKRS" • SDH microwave • Short name: MDRS 155 N 155/2300 3000 0 - 16 MLQAM MLQAM C ♦ MDRS 155/2 microwave radio - "Compact" "Compact" • SDH microwave • Short name: MDRS 155 C ♦ MDRS 155/2600 155/26000 0 - 128 MLQAM S • SDH microwave radio • Short name: MDRS 155 S
Classical Design Waveguide
Waveguide
RF f [GHz]
Circulator, Filter (CBN)
Circulator, Filter (CBN)
RF = Radio Radio freque frequency ncy e.g. 7.5 GHz, 18.7 GHz
TX
RX
Transmitter
Receiver
IF = Intermediate frequency e.g. 140 MHz Modulator 16 - 128 128 QAM QAM
Demodulator 16 - 128 QAM
BB = Baseband e.g. 155 Mbit/s Channel
Channel
Classical Design MD TX
CBN
f1
f2
CBN
f3
Tx side
Rx side
Chan Ch anne nell 3
MD
TX
Chan Ch anne nell 2
MD
TX
Chan Ch anne nell 1
MD
TX
f3
RX
DM
Chan Ch anne nell 1
f2
RX
DM
Chan Ch anne nell 2
f1
RX
DM
Chan Ch anne nell 3
TX
MD
f1
Chan Ch anne nell 3
RX DM
DM
f2
f3
RX
Chan Ch anne nell 1
Tx side
Rx side Band filter
Circulator
Absorber
Microw Mic rowave ave Radio Radio Technolog Technology y - Fre Frequen quency cy Patter Patterns ns f1a f1b f1 f1a
f1a
MD
f1’ f1b
f1b
TX
TX
MD
RX
RX
DM
f1b
f1a
CBN
DM
CBN
Duplex spacing Channel Channel spacing width
f1 f1a
f2 f2a
f3 f3a
f4 f4a
f1` f1b
Lower band
f2` f2b
f3` f3b
Upper band Allocated frequency range
f4` f4b
Frequency Frequen cy Patterns Patterns - Transm Transmission ission via 2 Pola Polarizatio rizations ns Orthomode transducer (OMT)
Exploitation of Frequency Patterns 40 MHz frequency pattern (e.g. 6.8 GHz) f1
f2
f3
f4
f1
f2
f3
f4
64 QAM
Channel spacing 40 MHz
Channel width 30 MHz
f1
f2
f3
f4
f1
f2
f3
f4
28 MHz frequency pattern (e.g. 7.5 GHz or 13 GHz) f1
f3 f2
128 QAM
64 QAM
f5 f4
f6 30 MHz Channel width
Channel spacing 28 MHz
f1
f2
f3
f4
f5
f6
f1
f2
f3
f4
f5
f6
128 QAM
26 MHz Channel width
Additional Attenuation 100
Rain 150mm/h
10 Rain 25mm/h
dB/km 1 Rain 16mm/h
Attenuation due to precipitation ... ♦
depends on the intensity ♦ depends on the radio hop length ♦ depends on the frequency
mm/h (millimeters (millimeters per hour)
0.1
0.01
1
2
5
10
20
50 1 00
Addit Add ition ional al Att Attenu enuat atio ion n - Mu Mult ltip ipath ath Pr Propa opaga gati tion on Half-power beamwidth, e.g. ...°
e.g. 50 km
approx. .... m
218 m λ
λ
= wavelength
Case 1
+
=
Case 2
+
=
Case 3
+
=
Microw Mic rowave ave Radio Radio Technol Technology ogy - Spac Space e Diversi Diversity ty ∆
∆
MD STM-1
DM +
TX RX RX
CBN Main CBN Div
CBN Main CBN Div
TX RX RX
MD STM-1
+ DM Length compensation
Maximum Radio Hop Lengths AntennaeDiameter
MDRS 155/3900-64 MLQAM With Space Diversity
1.2 m
MDRS 155/4700-64 MLQAM
2m
With Space Diversity
3m
MDRS 155/6200-64 MLQAM With Space Diversity MDRS 155/6800-64 MLQAM With Space Diversity MDRS 155/7500-64 MLQAM With Space Diversity MDRS 155/8000-64 MLQAM With Space Diversity MDRS 155/13000-64 MLQAM With Space Diversity
0
10
20
30
40
50
60
70
Hop Length / km Space Diversity Climate: Central Europe; BER=2x10E-5; Feeder: 2x30m; w/o Interference; Pout: 0.001%; rain is not considered
80
90
100
Microwave Micro wave Radio Techn Technology ology - Frequ Frequency ency Divers Diversity ity f f1
f3
f3a
MD T X MD T X Chan Ch anne nell 1
RPS
f3b
f1a
DM RX DM RX f1b
CBN
f1 f1a
f3 f3a
f1’ f1b
f3’ f3b
Microw Mic rowave ave Radio Radio Tech Technolo nology gy - Fre Fresne snell Zone Zone Distance d b
Radius b
1st Fresnel zone:d +1⋅
λ
2
Microwave Micro wave Radio Techn Technology ology - System Design Designation ation 3+1
Bit Error Ratio (BER) 1E-4 BER Radio hop interference
1E-5
1E-6 1E-7 BER measuring unit
BER =
Measured errors [bits] bits Data rate ⋅Time [s] s
Example: BER =
1E-8 1E-9 1E-10 1E-11
1E-12 100 bits =1.072 ⋅10−8 Mbits ⋅1min 155.52 s
-75
-70
-65 PRX [dBm] at A
Transmission Performance Transmission performance performance of radio hops Availability
Performance
Unavailable time BER > 1E-3 (t > 10 s) > 30% errored blocks (t > 10 s)
Radio hop
ITU-T G821 ITU-T G826
Failures caused by various factors
Available time 0 < BER < 1E-3 < 30% errored blocks
Errored Errored seconds seconds ES 0 < BER < 1E-3 < 30% errored blocks Severely errored seco second nds s SES SES BER > 1E-3 (t < 10s) > 30% errored blocks blocks (t<10 (t<10s) s)
Degraded minu minute tes s DM 1E-6 < BER < 1E-3
Error-free seconds EFS BER = 0 0% errored blocks
Transmission Performance BER 1E-1 (0.1) BER 1E-2 (0.01) BER 1E-3 (0.001) BER 1E-4 (0.0001) BER 1E-5 (0.00001) BER 1E-6 (0.000001) BER 1E-7 BER 1E-8 BER 1E-9 BER 1E-10 BER 1E-11 t [s]
•
ES - (Errored Seconds) • SES - (Severely Errored Seconds) • UT - (Unavailable Time) (SDH: (SDH: UAS - Una Unavaila vailable ble Seconds Seconds))
Terms Ter ms of Microwav Microwave e Radio Radio Technolog Technology y - Int Interf erface aces s T´ - Input Bas Base eband Z´ - Outp Output ut Modu Modula lato torr (ZF (ZF)) A´ - Outpu utputt Tran Transm smit itte terr B´ - Outp Output ut RF Filt Filter er (TX) (TX) C´ - Outp Output ut Ci Circ rcul ulat ator or (TX) (TX) D´ - Inp Input OMT (TX (TX) D - Outp Output ut OMT OMT (RX) (RX) C - Input Input Circu Circulato latorr (RX) (RX) B - Input Input RF RF Filte Filterr (RX) (RX) A - Inpu Inputt Rece Receiv iver er Z - Input Input Demo Demodu dulato latorr (ZF) (ZF) T - Outp Output ut Bas Baseb eband and
Z´
T´
MD
A´
PW
D´
B´
TX
Tx side C´
PW
D
B
A
Z
RX
T
DM
C
Rx side
Baseband Code CMI code
HDB-3 code
♦
CMI - Code Coded d Mark Mark Inversio Inversion n ♦ Free from DC due to alternating polarity ♦ Used for bit rates > 140Mbit/s •
Binary value: log. 0 − first clock half always negative − second edge always positive − always positive rising edge • Binary value: log. 1 − entire clock period alternating with positive and negative potential
♦
Modified AMI code ♦ Transmission code for 2, 8 and 34 3 4 Mbit/s • Additional bit V prevents sequences of more than three log. 0s. • Additional bit has same polarity as last data bit. • If no or an even number of log. 1s follows two violation bits, an AMI additional pulse is inserted three bits before the next violation bit.