Post on 06-Apr-2018
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System Model
9804649
AUC
H LR E IR
SS
BSS
M S C
B T S
M S
N M C and O M C
Swi tching System
S igna ling transmissio n
Cal l conn ections and
signa ling tran smissio n
B ase S ta tion System
O ther
n etworks
B S C
G M S C
V LR
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Network elements in GSM
MS
PLMN
PSTN
ISDN
AUC
EIRHLR
VLR
MSC
BSC
BTS
GMSC
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SA2
MSC
VLR
MSCMSC
VLR
BSC BSC
LA1LA2
GMSC
MSC
BTS
SA1
HLR
AUC
EIR
SA - Service Area
LA - Location Area
BTS - Base Transceiver Station
BSC - Base Station Controller
MSC - Mobile Switching Center
VLR - Visitor Location RegisterGMSC - Gateway MSC
EIR - Equipment Identity Register
AUC - Authentication Center
HLR - Home Location Register
Mobile identity
SIM card
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Base Station System
Ba se S ta tio n System
B S C
BTS
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BSS in Ericssons GSM Systems
9805050
MSC TRC BSC
BSSSS
RBS
BSC/
TRC RBS
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Transmission Rates in BSS
9805051
M SC /
V LR
TR C
B SC
RB S
B SC /
TR C
RB S
R B S
RB SRB S
R B S RB S
R B S
B SC
RB S
RB SRB S
RB S
M SC /V LR
B S C
RB SR B S
64 kbits/sp e rcal l
16 K b /sfu ll- ra te
3 3 .8 Kb /s p e rfu ll- ra te cal l
16 Kb /s
fu ll- ra te
16 Kb /s
fu ll- ra te
16 Kb /sfu ll- ra te
64 kbits/sp e rcal l
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Switching System
S S
M S C /V LR
E IR
IL R
G M S C
D TI
AUC
H LR
S M S -G M S C
S M S -IW M S C
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VLR-HLR Interaction
9805099
H LR
UpdateD
ele
te
M S C/VLR M S C/VLR
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HLR interrogationPSTN/
ISDNGMSCHLRMSC/VLR
IAMSend Routing
Information
Send Routing
Information
IAM
Provide
Roaming Number
ProvideRoaming Number
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Mobile Station
9600279
M EM o b ile
E q u i p m en t
S IM Subscr iber Id en tity
M od u le
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GSM interfaces
M S BTS B SC M S C HLR
VLR
M S C
EIR
VLR
Um Ab is A
B
C
E
F
D
G
AUC
H
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A Cell
9600270
Cell
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Macro, Mini, Micro and Indoor Cells
960022 3
A n te nn a posit io ns
M ac ro
M in i
MicroPico
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MSC Service Area
9600271
ce ll 6
ce ll 1 ce ll 5
ce ll 4 ce ll 2 ce ll 3
M S C
LA 1LA 3
LA 5
LA 4
V LR
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Relation Between Areas in GSM
9600 3 67
GSM Service Area
PLMN Service Area
(one per operator)
MSC Service Area
Location Area
Cell
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"Hardware" view of a Sample Network
HLR
EIR
AUC
GMSC
ILR
MSC/VLR 1PSTN
MSC Service Area 2
MSC Service Area 1
LEGENDMSC Boundary
BSC BoundaryPCM LinksBase Station
MSC/VLR 2
BSC 1B
BSC 1C
BSC 2B
BSC 1A
BSC 2A
BSC 2C
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"Software" view of a Sample Network
LA 1-B
LA 1-A
LA 2-D
LA 2-ACell 2-A-25
LA 2-B
HLR
EIR
AUC
GMSC
ILR
MSC/VLR 1PSTN
MSC Service Area 2
MSC Service Area 1
LEGENDMSC Boundary
BSC BoundaryPCM LinksBase Station
MSC/VLR 2
LA 2-C
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Authentication Procedure
MSC/VLR
1. RAND
3.SRES
MS2.MS calculates SRES using RAND + Ki(SIM-card) throug A3 and Kc using RAND+Kithrough A8.
4. CompareSRESreceived fromMSwithSRESin triplet. Iftheyareequal accessis granted.
MSC/VLR MobileserviceSwitching CenterMS MobileStation
RAND Random numberSRES Signed Response
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Authentication in GSM
VLR
MSC
HLRAUC
Subscriber number (IMSI)Code key (Ki)
Random number (RAND)Signal response (SRES)
RAND / SRES
RAND
SRES
Figure D.6.4
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Equipment Identification
27
M S C/VLR
M S
EIR
3. C heck IM EI
4 . Access /ba rr ing in fo
1 . IM EI request
2 . IM EI
IM EI In te rna ti onal M o b ile sta ti on Equipmen t Id en tity
EIR Equ i p m en t Id en tity R eg ister
M SC/VLR M o b ile servicesSwitch ing C en te r
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OSS CNA
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OSS Provides Central Supervision of all Network
9804645
OMC OMC
H LR
AUC/EIR
TR C
MSC
BSC
BTS
Operat ion and
Suppo rt Sys tem
NMC
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Gateway productsfor billing information
and service
SOG and BGW
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GSM Modes
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Operation Overview
Attached (On)
Detached (Off)
Idle
Busy
Roaming
Paging
Handover
Mr. Bond!!
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Roaming
9600275
M S C/VLR
M S C/VLR
LA 1
LA 2
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The RBS Listening for Channel Requests and
Measuring the Uplink on an Established
Connection
Signal strength!Quality!Timing!
Accessburst!
MS
MS
MS MS
RBS
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Monitoring BCCH Carriers
9600479
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GSM Frequency Bands
9805092
0 .8GHz 0 .9 1 .0 1 .1 1 .2 1 .3 1 .4 1 .5 1 .6 1 .7 1 .8 1 .9 2 .0
GSM 900 GSM 1800 GSM 1900
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Frequency bands for the different GSM-based
networks. (Values within brackets refer to E-GSM)
Network type
GSM 900 (880)890-915/(925)935-960 MHz GSM 900
GSM 1800 1710 - 1785/1805 -1880 MHz GSM 1800
GSM 1900 1850 - 1910/1930 -1990 MHz GSM 1900
EricssonsImplementations
Frequency bandUL/DL
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Uplink and Downlink on a Radio Channel
9804646
U p lin k
D o w nlink
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System Parameters
f
up link down link
Carrier spacing
Duplex spacing
Bandwidth spacing
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Duplex Distance
9805042
890 960915 93 5M H z
U p link D ow nlink
D u p lex D is tan ce (4 5 M H z)
Band w id th (2 x 25 M H z)
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Duplex distances for different frequency bands
S tandard GSM 900 GSM 1800 GSM 1900
Dup lex dis t. 45 MHz 95 MHz 80 MHz
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Carrier Separation
9805041
C a rrierS e p a ra tio n (200 KHz)
895 .4 895 .6M H z
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Neighboring Cells Cannot Have the Same
Frequency (Simplified)
9600 3 68
B
G
A
C
G
AD
F
F
E
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TDMA
9805008
0
F re q ue ncy 1
1 2 3 4 5 6 7
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Basic TD
MA frame, timeslot, and burst structures
0 1 2 3 4 5 6 7
4 .615 m s
3 57 1 26 1 57 3
B urst
148 B it s
156 .25 B it s
0 .577 m s
D a taT ra in ingD a ta
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Analog Signal
9805018
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Digital Signal
9805019
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A/D Conversion
9600 3 71
Analo g
A/D C o nversio n
D ig it al
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Analog Signal Sampling
9600372
t
Analog ue signa l
t
S am p ling
T s
t
S am p le d signa l
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Regeneration ofDigital Signal
9805020
T ran smit ted R eceived R e ge n e ra te d
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Quantization
9600 373
q 7
q 6
q 5
q 4
q 3
q 2
q 1
q 0
T s 2 T s 3 T s 4 T s 5 T s 6 T s 7 T s 8 T st ime
}
S am p le d
va lu e
Q u an tize d
va lu e
D = Q ua n tize d error
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Path loss
Shadowing
Rayleigh fading
Signal strength Time dispersion
Time Alignment
Radio Parameters that are important for GSM
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Problems Solution Fading
Distance Eventually leading to handover
Shadowing Make a better coverage of the cell or smaller cells
Rayleigh Antenna diversity- two antennas on the BS, 5-6 m apartRepeated change offrequencies after each frame
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Shadowing
9600 3 77
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Rx Signal Strength
9600 380
F ad ing
m a rg in
S S (dB)
D is tanc e (met ers )
G lob a l m ean va lu e
F ad ing d ip (R ay le igh )
R eceiver s e n sit ivity
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Rx Signal Strength Versus Distance
9600379
log (d is tan ce )
S
ignallevel(dB
)
P a th lo ss ( )
R ay le igh fad ing (-)
L og no rm al
fad ing ( )
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Rayleigh Fading
9600378
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Time Dispersion
9600521
1
1
1 .
0
0
2 .
1
1
3.
1
0
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The Time Alignment Problem
A. Close to BTSBTS
T DMA-frameB . Far away
from BTSA .
B .
TS0 TS1 TS2
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Intermodulation in a 900 MHz cellular system
890 900 910 920 93 0 940 950 960 M H z
RX band
Dup lex d is tance (D )
TX band
Alloca te d R X band (B)
(1 0 M H z in
this e xam p le )
Alloca te d TX band (B)
(1 0 M H z in this exam p le )IM 7 IM 5 IM 3
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System
GSM900
DCS1800
PCS1900
NMT450
Duplex
distance,
D, (MHz)
45
95
80
10
IM3
22.5
47.5
40.0
5.0
IM5
15.0
31.7
26.7
3.3
IM7
11.3
23.8
20.0
2.5
IM9
9.0
19.0
16.0
2.0
Maximum band, B, (MHz) to avoid IM order:
Worst-case relations
IM3 in Rx band ifD/B < 2
IM5 in Rx band ifD/B < 3
IM7 in Rx band ifD/B < 4
IM9 in Rx band ifD/B < 5
Definitions:IM3, IM5, etc.=Intermodulation products of 3rd, 5th, etc.,
D = Duplex distance (MHz)
B = Allocated band (MHz)
Worst case = IM from the lowest and
the highest frequencies in the allocated band
Intermodulation (IM) in cellular systems
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Co-Channel InterferenceCarrier
Interference
Distance
f1 f
1dB
C I
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Reuse distance and carrier-to-interference ratio
S (dB)
S(A,f1) S(B,f1)
Reuse distance for f1 Distance from A
>18 dB in analog systems
>7 dB in digital systemsC
I
Figure D.5.4
I C
A B
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Co-channel interference
f1
f1
B
A
Figure D.5.3
Acceptable
Speech quality
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Adjacent Channel Interference
AC
CarrierAdjacent
Distance
f1 f2
dB f2
= f1
+ 200 kHz
-9 dB
3 dB
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Locating the BTS close to the reflecting object to
combat ISI
D 2
D 0
D 1
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Pointing the antenna away from the reflecting object
to combat ISI
M o un ta in Site with an te nna
po in ting aw ay
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Space Diversity
9805015
T xR x (B )R x (A )
A n te nnaD iversity
D iversity
System
O utput
R eceiver
S e n sivity
L e ve l
R eceived
S igna l
L e ve l
A, B c o m b in ed
R ec eiv er A
R ec eiv er B
N o D iversity
T x R x
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Block coding
In form a tion
B lo ck
In form a tion
B lo ck
R edundan t
d ig its
B lo ck
cod ing
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Interleaving
P E TES TA NA N NAV E R AM e s sage
b lo ckP
S
A
V
?
?
?
?
T
A
N
R
E
N
A
A
P ?TES ?ANA ?NAV?RA
S ing le
b it
errors
P SAV
E T N E
TA N R
E NA A
T x s ide R x s ide
P
S
A
V
E
T
N
E
T
A
N
R
E
N
A
A
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Interleaving for full rate speech1
9
17
25
449
2
10
450
3
11
451
4
12
452
5
13
453
6
14
454
7
15
455
8
16
456
8 fram es
57 bits
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Second level of interleaving1st C O L U M N IN A
2 n d C O L U M N IN A
3rd C O L U M N IN A
4 th C O L U M N IN A
5 th C O L U M N IN A+1st C O L U M N IN B
LA S T B U R S T W I T H IN FO R MATIO N
B IT S F R O M T H E A - B L O C K
LA S T B U R S T W I T H IN FO R MATIO N
BIT S F R O M T H E B - B L O C K
A1 A17 A3 3 ... A9 A25 A41...
A4 A 20 A3 6 ... A12 A28 A44...
B1 A5 B1 7 A2 1 B 3 3 A 3 7 ... B9 A1 3 B2 5 A2 9 B4 1 A4 5 ...
B4 A8 B2 0 A2 4 B 3 6 A4 0 ... B12 A16 B28 A 3 2 B4 4 A4 8 ...
C1 B5 C1 7 B2 1 C 3 3 B 3 7 ... C9 B1 3 C2 5 B2 9 C4 1 B4 5 ...
C4 B8 C2 0 B2 4 C 3 6 B4 0 ... C12 B16 C28 B 3 2 C4 4 B4 8 ...
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Channel Coding
9805016
B lock
coder 5 0 V ery impor tan tbits
1 32 Im p o r tan tbits
7 8 N o ts o impor tan tbits
1 :2
Conv o lu t ional
Code r
4 56
4 Ta il bits
5 3 b its 3 78 bits
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Channel coding and interleaving for control
channels
23 octets 21 octets 2 octets
BCCH, CCCH, SDCCH, FA C C H SA C C HL2 b loc k L2 b loc k
18 4 18 4
184 40
224 4
22 4
22 8
L2 b lo ck
E rror D etection (FIRE)
45 6
2 x 228 = 456
57 57 57 57 57 57 57 57
45 6 bits in te rlea ve d o ve r 8 hal fbursts
BCCH, CCCH, SDCCH, SACCH/C
4 fram es 8 fram e s
FA C C H
10 4 fram es , 480 m s
L2 b lo ck + F IRE
L2 b lo ck + F IRE co ded wi th R = 1 /2
TAIL
SACCH/T
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Frequency Hopping
9600535
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
D ow nlink C 1
U p lin k C 1
N N + 1
T D MA fram e no .
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
D ow nlink C 2
U p lin k C 2
N N + 1
T D MA fram e no .
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Timing Advance
9600538
0 1 2 3 4 5 6 7
T im e
0 1 2 3 4 5 6 7
S ynchron iza tio n t ime
S ta rt
S e nd in g
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Segmentation and Speech Coding
9600522
01100011000111110011100
Speech Code
20 ms
Speech S ignal
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Interleaving of 20 ms of Encoded Speech
9600531
1
9
1 7
2 5
I
I
I
I
II
I
I
I
I
I
I
449
2
10
I
I
I
I
I
I
II
I
I
I
I
I
I
4 50
3
11
I
I
I
I
I
I
II
I
I
I
I
I
I
4 51
4
1 2
I
I
I
I
I
I
II
I
I
I
I
I
I
4 52
5
1 3
I
I
I
I
I
I
II
I
I
I
I
I
I
4 5 3
6
14
I
I
I
I
I
I
II
I
I
I
I
I
I
4 54
7
15
I
I
I
I
I
I
II
I
I
I
I
I
I
4 55
8
1 6
I
I
I
I
I
I
II
I
I
I
I
I
I
456
8 b lo c k s
5 7 bits
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Speech Frame
9600532
2 0 m s s p e e c h
4 56 bits = 8 x57
A20 m s speech
456 bi ts = 8x57
B2 0 m s s p e e c h
4 56 bits = 8 x57
C20 m s s p e e c h
456 bits = 8 x57
D
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Second Level of Interleaving
9600534
A/8
A/8
A/8
A/8
B/8 A/8
B/8 A/8
B/8 A/8
B/8 A/8
C /8 B/8
C /8 B/8
C /8 B/8
C /8 B/8
D /8 C /8
D /8 C /8
D /8 C /8
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GSM Transmission Process
9600539
3 3.8 kbit/s
22 .8 kbit/s
1 3 kbit/s
8 kHz1 3 bits
Transmitting par t
Receiving par t
S p eake r
R eceiver
D em od u la to r
Adaptive
E q ual iza tion
D e -ciphering
D e - in te rlea v ing
C hann e l deco d ing
Speech de cod ing
D/A-co nversion
T ran smitter
M od u la to r
B urstform a tti ng
C iphering
In te rlea v ing
C hann e l cod ing
Speech co d ing
S e gm en ta tio n
A/D-co nversion
Microphone
1 3 kbit/s
Transmitting part
Receiving par t
T ran smitter
M od u la to r
B urstform a tti ng
C iphering
In te rlea v ing
C hann e l cod ing
D/D-co n version
8 kH z8 bits
64 kbit/s P C M
R eceiver
D em od u la to r
Adaptive
E q ualiza tion
D e -ciphering
D e -in te rlea vi ng
C hann e l D e co d ing
G S M Network
M o b ile equipmen t
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GPRS Logical Architecture
Traffic and signaling
Signaling
TE Terminal Equipment
MT Mobile TerminalMS Mobile Station
BSS Base Stat ion SystemBTS Base Transceiver Station
BSC Base Station Controller
GMSC Gateway Mobile Services SwitchingCenter
MSC Mobile services Switching Center
VLR Visitor Location RegisterHLR Home Location Register
AUC Authentication Center
EIR Equipment Identity RegisterSGSN Serving GPRS Support Node
GGSN Gateway GPRS Support NodeUm Air Interface
A, Abis Interfaces (GSM)
Gx Interfaces (GPRS)
ExternalIP Network
(CorporateLAN)
Gi
TE MT
MS
BSC
GMSC
MSC/VLR
SGSN
EIR
HLR
AUC
GGSNIP-BackboneNetwork
External
IP Network(Internet)
External
X.25 Network
GsGf
Gr
BTS
Gb
UmISDN/PSTN
Gn
A
Other
PLMN
Gp
BSS Abis