7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
1/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved
www.huawei.com
Internal
OMA000001
GSM Fundamentals
ISSUE 4.0
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
2/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 2
Upon completion of this course, you will be able to:
Grasp basic idea of GSM system such as
frequency spectrum, frequency reuse etc.
Grasp the structure of the GSM system and the
protocol used.
Grasp certain numbers that refer to BSS
Grasp the 4 kinds of channel combination and
understand the idea of multi-frame.
Know some radio techniques
Get the idea of EDGE
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
3/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 3
References
BSS Feature Description
BSS Signaling Analysis Manual
BSC Technical Manual
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
4/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 4
Chapter 1 GSM System Overview
Chapter 2 GSM Network Structure
Chapter 3 Service Area and Number Planning
Chapter 4 Channels on the Wireless Interface
Chapter 5 Radio Techniques
Chapter 6 GPRS & EDGE Introduction
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
5/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 5
GSM system overview
The GSM system is a frequency- and time-division cellular system,
each physical channel is characterized by a carrier frequency and a
time slot number
Cellular systems are designed to operate with groups of low-power
radios spread out over the geographical service area. Each group ofradios serve MSs presently located near them. The area served by
each group of radios is called a CELL
Uplink and downlink signals for one user are assigned different
frequencies, this kind of technique is called Frequency Division Duplex
(FDD)
Data for different users is conveyed in time intervals called slots ,
several slots make up a frame. This kind of technique is called Time
Division Multiple Access (TDMA)
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
6/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 6
GSM Development
Standard Protocol for GSM take effect
System was named as Global System forMobile Communication
GSM system began to provide service in Europe(2G)
Provide services for the whole world
Micro Cell Technique is used in GSM system
1989
1991
1992
1994
1996
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
7/70HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 7
Cell Technique
A certain radio coverage area formed by a set of transceivers that
connected to a set of antennas is called a CELL.
Macro Cell
In the beginning , High-Power BTSs are adopted to provide services.
The BTS covers a wider area , but its frequency utilization is not
efficient. So , it can only provide a few channels for subscribers.
Micro Cell
Later the Low-Power BTS joins the system for getting a better servicearea with high capacity . At the same time it adopts the frequency
reuse technique to improve the efficiency of the frequency utilization
and also the whole capacity of the network.
Macro Cell and Micro Cell
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
8/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 8
Multiple Access Technique
Multiple Access Technique allows many subscribers to use the
same communication medium.
There are three kinds of basic Multiple Access Technique :
FDMA , TDMA and CDMA.
GSM system adopt FDD-TDMA (FDMA and TDMA together).
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
9/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 9
FDMA
FDMA uses different frequency
channels to accomplish
communication.
The whole frequency spectrum
available is divided into many
individual channels (for
transmitting and receiving)every
channel can support the traffic for
one subscriber or some controlinformation.
Frequency
Time
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
10/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 10
TDMA
TDMA accomplishes the
communication in different
timeslot.
A carrier is divided intochannels based on time.
Different signals occupy
different timeslots in certain
sequence , that is , many
signals are transmitted onthe same frequency in
different time.Time
Frequency
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
11/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 11
CDMA
CDMA accomplishes the
communication in different
code sequences.
Special coding is adopted
before transmission, thendifferent information will
lose nothing after being
mixed and transmitted
together on the same
frequency and at thesame time.
Time
Frequency
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
12/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 12
GSM 900
Duplex Separation: 45MHzChannel Bandwidth: 200KHz
The Frequency Spectrum
Uplink
890 915 935 960MHz
Downlink
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
13/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 13
Duplex Separation: 95MHzChannel Bandwidth: 200KHz
Base Station Receive
1710 1785 1805 1880MHz
Base Station Transmit
DCS 1800
The Frequency Spectrum
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
14/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 14
The Frequency Spectrum
FrequencySpectrum
Range (MHz) Uplink FrequencyFrequencyPointAvailable
DownlinkFrequency
GSM 450450.4~457.6
460.4~467.6Fu(n)=450.6+0.2(n-259) 259
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
15/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 15
Frequency Reuse
The frequency resource of mobile system is very limited.
The different Subscribers can use the same frequency in
different places.
The quality of communication must be ensured.
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
16/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 16
Frequency Reuse
7(Site)X 1(Cell) reuse
2
1
2
3
4
5
6
7
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
17/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 17
4 site X 3 cells reuse
1
8
9
210
46
5 37
11
12
R
Frequency Reuse
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
18/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 18
Cell Types
Omni
1
120degree
1
23
Omni-directional Cell
120 Degree Cell
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
19/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 19
Chapter 1 GSM System Overview
Chapter 2 GSM Network Structure
Chapter 3 Service Area and Number Planning
Chapter 4 Channels on the Wireless Interface
Chapter 5 Radio Techniques
Chapter 6 GPRS & EDGE Introduction
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
20/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 20
GSM-GPRS Network Component
GSM /GPRS BSS
BTS
BSC
BTS
BSC
PCU SS7
SMS system
PSTN
ISDN
Internet,
Intranet
MSC/VLR GMSC
HLR/AUC
SGSN
CGBG
GGSN
GPRS Backbone
Other PLMN
MS
MS
OMC
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
21/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 21
Interface Between Different Entities
GSM /GPRS BSS
BTS
BSC
BTS
BSC
PCU SS7
SMS system
PSTN
ISDN
Internet,
Intranet
MSC/VLR GMSC
HLR/AUC
SGSN
CGBG
GGSN
GPRS backbone
Other PLMN
A
Gb
Gi
Gp
C/D/Gs
Gr/Gs/Gd/GeGc
Ga
Abis
Um
MS
MS
OMC
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
22/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 22
Mobile StationMS
International Mobile Equipment Identity (IMEI)
Mobile Equipment
MS=ME+SIM
International Mobile Subscriber Identity (IMSI)
Subscriber Identity Module
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
23/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 23
Subscriber Identity Module SIM
International Mobile Subscriber Identity
(IMSI)
Temporary Mobile Subscriber Identity (TMSI)
Location Area Identity (LAI)
Subscriber Authentication Key (Ki)
SIM
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
24/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 24
BTS
BSC
TC/SM
BSS
MSC
Base Station Subsystem BSS
The Base Station Controller
BSC
The Base Transceiver Station
BTS
The Trans-coder TC and
Sub multiplexer (SM)
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
25/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 25
BTS
BSC
TC/SM
BSS
MSC
Packet Control Unit-----PCU
Packet data
switching
Bridge between
SGSN and BSC
Provide Pb and
Gb interface
GPRSBackbone
PCU SGSN
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
26/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 26
Mobile-service Switching Center MSCHome Location Register HLRVisitor Location Register VLREquipment Identity Register EIRAuthentication Center AUCEcho Cancellor EC
AUCHLR
MSC/VLR
PSTN
NSS
EIROMC
BSS
EC
The Network Switching System
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
27/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 27
Mobile-service Switching Center MSC
Call Processing
Operations and Maintenance Support
Interface management Inter-network & Inter-working
Billing
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
28/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 28
Home Location Register HLR
Subscriber ID (IMSI and MSISDN)
Current subscriber VLR (current location)
Supplementary service information
Subscriber status (registered/deregistered)
Authentication key and AuC functionality
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
29/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 29
Visitor Location Register VLR
Mobile Status (IMSI attached / detached / busy / idle etc.)
Location Area Identity(LAI)
Temporary Mobile Subscriber Identity(TMSI)
Allocating the Roaming Number
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
30/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 30
IMEI is Checked In White List
IMEI is Checked in Black/Grey List
If NOT found
EIR focus on theequipment , not thesubscriber!!
Equipment Identity Register EIR
White List
Black List
Grey List
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
31/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 31
OMC Functional Architecture
OS
MMI
DB
Event/AlarmManagement
SecurityManagement
ConfigurationManagement
PerformanceManagement
FaultManagement
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
32/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 32
Chapter 1 GSM System Overview
Chapter 2 GSM Network Structure
Chapter 3 Service Area and Number Planning
Chapter 4 Channels on the Wireless Interface
Chapter 5 Radio Techniques
Chapter 6 GPRS & EDGE Introduction
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
33/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 33
Service Area
PLMN service area
......
Service Area
MSC service area...
Location area...
cell
PLMN service area PLMN service area
MSC service area...
Location area...
cell
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
34/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 34
LAI
Location Area Identification
The LAI is the international code for a location area.
MCC: Mobile Country Code It consists of 3 digits .For example: The MCC of China is "460"
MNC: Mobile Network Code It consists of 2 digits .For example: The MNC of China Mobile is "00"
LAC: Location Area Code It is a two bytes hex code.The value 0000 and FFFF is invalid.
For example: 460-00-0011
MCC MNC LAC
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
35/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 35
CGI
The CGI is a unique international identification for a cellThe format is LAI+CI
LAI: Location Area Identification
CI: Cell Identity. This code uses two bytes hex code to
identify the cells within an LAI.For example : 460-00-0011-0001
CGI: Cell Global Identification
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
36/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 36
BSIC
NCC: PLMN network color code. It comprises 3 bit. Itallows various neighboring PLMNs to be
distinguished.BCC: BTS color code. It comprises 3 bit, used to
distinguish different cells assigned the samefrequency!
NCC BCC
BSIC
BSIC Base Station Identification Color Code)
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
37/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 37
CC: Country Code. For example: The CC of China is "86".
NDC: National Destination Code. For example: The NDC of
China Telecom is 139, 138, 137, 136, 135.SN: Subscriber Number. Format:H0 H1 H2 H3 ABCD
Example: 86-139-0666-1234
MSISDN
CC NDC SN
National (significant)Mobile number
Mobile station internationalISDN number
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
38/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 38
MCC: Mobile Country Code It consists of 3 digits .For example: The MCC of China is "460"
MNC: Mobile Network Code It consists of 2 digits .For example: The MNC of China Telecom is "00"
MSIN: Mobile Subscriber Identification Number. H1H2H3 S ABCDEFFor example: 666-9777001
NMSI: National Mobile Subscriber Identification MNC and MSINform it together.
For Example of IMSI : 460-00-666-9777001
Not more than 15 digits
3 digits 2 digits
IMSI
MCC MNC MSIN
NMSI
IMSI
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
39/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 39
TMSI
The TMSI is assigned only after successful subscriberauthentication.
The VLR controls the allocation of new TMSI numbers and notifiesthem to the HLR.
TMSI is used to ensure that the identity of the mobile subscriberon the air interface is kept secret.
The TMSI consists of 4 bytes( 8 HEX numbers) and determined bythe operator.
TMSI: Temporary Mobile Subscriber Identification)
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
40/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 40
IMEI
TAC FAC SNR SP
IMEI
IMEI: International Mobile Station Equipment Identification
TAC: Type approval code, 6 bit, determined by the type approval center
FAC: Final assembly code, 2 bit, It is determined by the manufacturer.
SNR: Serial number, 6 bits, It is issued by the manufacturer of the MS.
SP: 1 bit , Not used.
Check the IMEI in your MS : *#06#
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
41/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 41
Chapter 1 GSM System Overview
Chapter 2 GSM Network Structure
Chapter 3 Service Area and Number Planning
Chapter 4 Channels on the Wireless Interface
Chapter 5 Radio Techniques
Chapter 6 GPRS & EDGE Introduction
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
42/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 42
2 30 16 74 52 3
The physical channel is the medium over which theinformation is carried: 200KHz and 0.577ms
0 1
TDMA FRAME
Timeslot The information carried in one timeslot is called a burst
Physical Channel and Logical Channel
The logical channel consists of the information carried
over the physical channels
TDMA FRAME
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
43/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 43
Two types of Logical Channel
Traffic Channel (TCH) :
Transmits traffic information, include dataand speech.
Control Channel (CCH) :
Or Signaling Channel, transmits all kinds ofcontrol information.
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
44/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 44
Traffic Channel (TCH)
TCHTraffic Channels
Speech
TCH/FS
Data
TCH/HSTCH/9.6 TCH/2.4
TCH/4.8
TCH Traffic ChannelTCH/FS Full rate Speech ChannelTCH/HS Half rate Speech ChannelTCH/9.6 Data Channel 9.6kb/sTCH/4.8 Data Channel 4.8kb/sTCH/2.4 Data Channel 2.4Kb/s
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
45/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 45
FCCHSCH
CCH (Control Channels)
DCCH
SDCCH
BCH
BCCH Synch. CH.ACCH
SACCHFACCH CCCH
RACH CBCH
PCH/AGCH
Broadcast Control Channel BCCHCommon Control Channel CCCHDedicated Control Channel DCCH
Associated Control Channel ACCH
Control Channel (CCH)
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
46/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 46
CCH
BCH
BCCHSynch.
Channels
SCH FCCH
The information carried on the BCCH
is monitored by the MS
periodically when it is in idle modeBCCH: Broadcast Control Channel
FCCH: Frequency Correction Channel
SCH: Synchronization Channel
Broadcast Control Channel BCCH
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
47/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 47
CCH
CCCH
RACHuplink
CBCH
downlink
PCH/AGCHdownlink
The CCCH is responsible fortransferring control informationbetween all mobiles and thenetwork.
RACH: Random Access Channel
PCH: Paging Channel
AGCH: Access Granted Channel
CBCH: Cell Broadcast Channel
Common Control Channel CCCH
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
48/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 48
CCH
DCCH
SDCCH
FACCH SACCH
DCCH is assigned to a singlewireless connection formeasurement and handoverpurpose.
SDCCH: Stand-alone DedicatedControl Channel
ACCH:Associated Control ChannelSACCH: Slow Associated
Control Channel
FACCH: Fast Associated ControlChannel
ACCH
Dedicated Control Channel DCCH
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
49/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 49
RACH CCCHCCH
SDCCH
SACCH
FACCH
TCH/F
TCH/H
DCCH
TCH
DCH
Uplink Logical channel
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
50/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 50
FCCH
SCH
BCCH
PCH
AGCH
BCCH
CCCH
CCH
SDCCH
SACCH
FACCH
TCH/F
TCH/H
DCCH
TCH
DCH
Downlink Logical channel
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
51/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 51
Allocate signaling channel
FCCH
SCH
BCCH
PCH
RACH
AGCH
SDCCH
SDCCH
TCH
FACCH
Power-off
Idle mode
Dedicated mode
Idle mode
How to use these channels?
Search for frequency correction burst
Search for synchronous burst
Extract system information
Monitor paging message
Send access burst
Set up the call
Allocate voice channel
Conversation
Release the call
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
52/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 52
Packet data channel (PDCH)
Comprising packet service channel and packet control channel
Packet service channel (PDTCH) Combined into the single-directional service channel
Packet control channel
Broadcast control channel: PBCCH Public control channel: PPCH, PRACH, PAGCH
Private control channel: PACCH, PTCCH
TCH
BCCH
SACCH
Packet logic channel
CCCH
TCH
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
53/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 53
GSM Logical Channel Combination
Main BCCH combination FCCH + SCH + BCCH + CCCH
SDCCH combination SDCCH/8 + SACCH/8
Combined BCCH BCCH + CCCH +SDCCH/4 + SACCH/4
TCH/FR combination TCH/F + FACCH/F + SACCH/F
TCH/HR combination TCH/H + FACCH/H + SACCH/H
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
54/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 54
Packet logic channels (PDCH) can be combined via the following three modes
Mode 1: PBCCH+PCCCH+PDTCH+PACCH+PTCCH;
Mode 2: PCCCH+PDTCH+PACCH+PTCCH;
Mode 3: PDTCH+PACCH+PTCCH
In case of small GPRS traffic, GPRS and circuit services use the same BCCH
and CCCH in the cell. In this case, only combination mode 3 is needed in the cell
With the increase of traffic, the packet public channel should be configured in the
cell. Channel combination mode 1 and mode 2 should be adopted
Combination ofpacket logic channel
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
55/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 55
TDMA Frames
0 1
0 1 2 43 46 47 48 5049
51 Frame Multi-frames
0 1 10
CONTROLCHANNELS
2 3 4 5 6 7 2 3 5 764
GSM Multi-frames
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
56/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 56
GSM Multi-frames
TDMA Frames
0 1
0 1 2 43 21 22 23 2524
26 Frame Multi-frames
0 1 10
TRAFFICCHANNELS
2 3 4 5 6 7 2 3 5 764
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
57/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 57
Chapter 1 GSM System Overview
Chapter 2 GSM Network Structure
Chapter 3 Service Area and Number Planning
Chapter 4 Channels on the Wireless Interface
Chapter 5 Radio Techniques
Chapter 6 GPRS & EDGE Introduction
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
58/70
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
59/70
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
60/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 60
Timing Advance (TA)
Transmission delay t
Transmission delay t
TA
The mobile phone should
send the signal in advance!
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
61/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 61
Multi-path Fading
Diversity
Frequency Hopping
Time Dispersion
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
62/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 62
DiversityWhats Diversity?
Receive diversity provides an effective technique for both
overcoming the impact of fading across the radio channel and
increasing the received signal to interference ratio.
The former is achieved by ensuring uncorrelated (i.e. low
enough correlated) fading between antenna branches i.e. not
all antennas experience fades at the same time.
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
63/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 63
Kinds of Diversity
Time diversity
Coding, interleaving
Frequency diversity
Frequency hopping
Space diversity
Multiple antennas
Polarization diversity
Dual-polarized antennas
Multi-path diversity
Equalizer
t
f
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
64/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 64
Frequency HoppingFrequency
f 0
Frame
f 1
f 2
f 3
f 4
Time
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
65/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 65
Chapter 1 GSM System Overview
Chapter 2 GSM Network Structure
Chapter 3 Service Area and Number Planning
Chapter 4 Channels on the Wireless Interface
Chapter 5 Radio Techniques
Chapter 6 GPRS & EDGE Introduction
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
66/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 66
57.6kbps
115kbps
384kbps
2Mbps
GSM
HSCSD
GPRS
EDGE
IMT-2000
9.6kbps
2G
2.5G
3G
GSM Development Evolution
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
67/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 67
Data rate of EDGE and GPRS
8PSKGMSK
9.0
13.415.6
21.4
8.811.2
14.817.6
22.4
29.6
44.8
54.4
59.2
0.0
10.0
20.0
30.0
40.0
50.0
60.0
CS-1 CS-2 CS-3 CS-4 MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9
Kbps
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
68/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 68
Downlink, 4 TS, MCS-9
Huawei EDGE Test Result
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
69/70
HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 69
The basic idea of GSM
The frequency spectrum used in GSM
The structure of GSM
Certain service area and numbers
Some radio techniques used in GSM
Evolution of GSM
Summary
7/30/2019 00_oma000001 Gsm Fundamentals Issue4.0
70/70
www.huawei.com
Thank You