41490970-GSM-Basic
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Transcript of 41490970-GSM-Basic
Engineering TrainingEngineering TrainingZXG10-BSSZXG10-BSS
Goal and Objectives
•Goal•Be capable of installing and commissioning on ZXG10-BSS
•Objectives• Be familiar with GSM fundamental• Be familiar with the base principles of ZXG10-BSC,BTS• Be good at OMCR operation• Be familiar with common operation of Solaris and Oracle DB• Be able to complete installation and commissioning independently
Feb 20 ~ Mar 4
GSM Fundamentals BSC Fundamentals OMCR Fundamental and Operation BTS Structure Equipment Installation Solaris Maintenance OMCR Server Operation Data Configuration-1 Data Configuration-2 OMCR Installation On-site training
Agenda
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement
Agenda
AMPS ( America )NMT ( North Europe )
TACS ( U.K. )
Analog
Digital
D - AMPS PDCGSM
CDMA
Evolution
Development of Mobile Communication
TACS (U.K.)
• Not standard interface• No Mobile Data Services• Less efficiency of the Freq• No roaming automatically• Lower security
Disadvantages of First Generation Analog Mobile Communication System
NMT (North Europe)
AMPS(America)
Development of Mobile Communication
PDC
• High efficiency of the Freq• Mobile Data Services available• Automatic roaming• High security• Better quality of speech• More flexible on new services
Advantages of 2G Digital Mobile Communication System
CDMAGSM
Development of Mobile Communication
Worldwide Mobile Subscribers: 1,155 millionSource: Gartner Dataquest (October 2002)
GSM69%
CDMA13%
TDMA9%
PDC5%
Analog4% GSM
CDMA
TDMA
PDC
Analog
Worldwide GSM System Application
Worldwide Mobile Penetration Rate
Source: Gartner Dataquest (October 2002)
Percentage
0
20
40
60
80
100
1998 2000 2002 2004
Africa Asia/Pacific and Japan
Latin America North America
Western Europe Total Worldwide
Development of Mobile Communication
Basic Theory Network Architecture Multiple Access Mode System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
MSC/VLR
HLR/AUC EIR SC/VM
OMC
BSC
BTSPSTNISDN
PSPDN
MS
BSS
MSS
Um
Abis
BIEA
F
C
H
MSC/VLR
E
GSM Network Structure
Terms
• MS : Mobile Station• BSS: Base Station Subsystem• BSC: Base Station Controller• BTS: Base Transceiver Station
• MSC: Mobile Services Switching Center• OMC: Operation and Maintenance Center• AUC: Authentication Center• EIR: Equipment Identification Register
Terms
• HLR: Home Location Register• VLR: Visitor Location Register• MS: Mobile Station• ISDN: Integrated Services Digital
Network• PSTN: Public Switched Telephone
Network• PSPDN: Packet Switched Public Data
Network• PLMN: Public Land Mobile Network
holds all the switching functions
manages the necessary radio resources,
updating the location registration
carrying out the inter-BSC and inter-MSC tender
Inter-working with other networks (IWF).
GSM Network Entity
MSC
Manages the mobile subscribers database
subscriber information
part of the mobile location information
3 identities essentialthe International Mobile subscriber Identity
the Mobile station ISDN Numberthe VLR address
GSM Network Entity
HLR
VLR dynamically stores subscriber information needed to handle incoming/outgoing calls Mobile Station Roaming Number When a roaming mobile enters an MSC area. This MSC warns the associated VLR of this situation; the mobile enters a registration procedure through which it is assigned a mobile subscriber roaming number (MSRN)
Temporary Mobile Subscriber Identity, if applicableThe location area in which the mobile has been registeredData related to supplementary service parameters
GSM Network Entity
AUC/EIR Authentication Center(s) (AUC)
Providing the authentication key used for authorizing the subscriber access to the associated GSM PLMN.
Equipment Identity Register(s) (EIR)
Handling Mobile Station Equipment Identity
GSM Network Entity
MSC/VLR
HLR/AUC EIR SC/VM
OMC
BSC
BTSPSTNISDN
PSPDN
MS
BSS
MSS
Um
Abis
BIEA
F
C
H
MSC/VLR
E
GSM Network Structure
Equipment used by mobile service subscribers for access to services.
.
Mobile Station
MS
Mobile EquipmentSubscriber Identity Module (SIM)
Mobile stations are not fixed to one subscriber. A subscriber is identified with the SIM card.
Base Transceiver Station (BTS)
Wireless transmissionWireless diversityWireless channel encryptionConversion between wired and wireless
signalsFrequency Hopping
BaseBand Unit: voice and data speed adapting and channel codingRF Unit: modulating/demodulating, transmitter and receiverCommon Control Unit: BTS operation and maintenance
GSM Network Entity
BTS
Managing Wireless network-BSSMonitoring BTS
Controls:Wireless link distribution between MS and BTSCommunication connection and disconnectionMS location, handover and pagingVoice encoding, transecoding (TC), rate,
adaptation, The operation and maintenance functions of
BSS.
BSC
GSM Network Entity
TC in BSC
• The Position of TC?
• Voice conversion16kbit/s RPE-LTP 64kbit/s A-law PCM codes.
Typically TC is located between MSC and BSC.
TC in BSC
MS
Ate r interfac e
Um interface
BSC
BIE
BTS
BIE
Abisinterface
SM SM TC
A interfa ce
MSC
OMC
Q3 interface
Fig.1-3 BSS Structure
Cell
Location Area
MSC Service Area
PLMN Service Area
GSM Service Area
Location Area Identification
GSM Service Area (Global area)PLMN Service Area (one or several in one country)MSC Service Area (areas covered by one MSC)Location Area (MS does not update VLR data inside of LAC))Cell (the smallest unit the network can identify in wireless)
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
O AM
S ervice carrie r
CM
MM
RR
Subsc riber
Tran smissi on
Overview: Function Layers of GSM-1
CM
MM
RR
LAPDm
MS
RR
LAP Dm
Um
LAPD
BTSM
LAPD
Abis
RR
BTSM SCCP
MTP3
BS SAP
BTS BSC
MTP2
SCCP
MTP3
BS SAP
MTP2
CM
MM
MSC
A
Protocol Stack Structure of GSM
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
Concept: channel is composed of a
series of timeslots of periodicity. Different signal energies are distributed into different timeslots. The adjacent channel interference is restricted by connection choosing from time to time. So the useful signal is passed only in the specified timeslot.
GSM adopts TDMA/FDMA mode channel width: 200KHz each channel has 8 timeslots
GSM adopts TDMA/FDMA mode channel width: 200KHz each channel has 8 timeslots
User 1
User 2
User 3
Frequency
time
TDMA
FDMA
Concept: In a relative narrow channel inside a
frequency domain, the signal power is concentrated to transmit the signal. Different channels are distributed into different channel. The interference from and to adjacent channels is restricted by the BPF. Thus, in specified narrow channel, only the useful signal energy can be passed, while any other signal will be excluded.
User
1 User
2 User
3
Frequency
Time
FDMA TDMA CDMA Demonstration
User
1 User
2 User
3
User 1
User 2
User 3
User 1
User 2
User 3
FDMA TDMA
CDMA
frequency
frequency
frequency
time
time time
code
GSM Timeslot and Frame structure
time
Frequency
BP15/26ms
200KHz
interval
Frequency Resource
GSM900 :
up: 890~915MHz
down: 935~960MHz
duplex interval: 45MHz
bandwidth: 25MHz ,frequency interval: 200KHz
GSM1800 :up: 1710-1785MHz down: 1805-1880MHzduplex interval: 95MHz , working bandwidth: 75MHz ,frequency interval: 200KHz
EGSM900 :
up: 880~890MHz
down: 925~935MHz
duplex interval: 45MHz
bandwidth: 10MHz ,frequency interval: 200KHz
GSM1900MHz:up:1850~1910MHzdown:1930~1990MHzduplex interval: 80MHz , working bandwidth: 60MHz ,frequency interval: 200KHz
1800MHz
1900MHz
900MHzWhich one?
Single Band Network General Priority
High
Low
Reason
For SubscriberFor Operator
Propagation Characteristic
New Operator
Frequency Resource
1800MHz
1900MHz
900MHz
Single Band Network
Single Band
Dual Band
Triple Band
In a sense, the network determines the handsets can be selected.But nowadays, most handsets support dual band.
Frequency Resource
Propagation characteristic
Cell coverage radius :
The higher the propagation frequency
The higher the propagation loss
The smaller the cell coverage radius.
900MHz
1800MHz
1900MHz
Single Band Network
Frequency Resource
We know
0 2045 2046 2047321 2044
3210 4947 48 50
0 24 251
1 super high frame = 2048 super frame = 2715648 TDMA frame
1 super frame = 1326 TDMA frame ( 6.12s )
0 1 2524 504910
1 multiplex frame = 26 TDMA frames ( 120ms )1 multiplex frame = 51 TDMA frame
0 1 765432
1 TDMA frame = 8 timeslot ( 120/26 = 4.615ms )
BCCHCCCHSDCHSACCH/TCH
FACCH
Timeslot and Frame structure
0 1 765432
8 9 151413121110
16 17 232221201918
The physical channel adopts FDMA and TDMA techs.On the time domain, a specified channel occupies the same timeslots in each TDMA frame, so it can be identified by the timeslot number and frame number.
Physical Channel
channel
TCH
CCH
Voice CH
Data CH
FR Voice Traffic Channel (TCH/FS)
HR Traffic Channel (TCH/HS)
4.8Kbit/s HR TCH (TCH/H4.8)
9.6Kbit/s FR TCH(TCH/F9.6)
4.8Kbit/s FR TCH (TCH/F4.8)
BCH
FCCH (down)SCH (down)BCCH (down)
CCCHRACH (up)AGCH (down)
PCH (down)
DCCHSDCCHFACCHSACCH
14.4Kbit/s FR TCH (TCH/F14.4)
Enhanced FR Traffic Channel (TCH/EFR)
Channel Type-Summary
Channel Type
Traffic ChannelTransmit voice and data
Signaling Channeltransmit the signaling and synchronous data between BTS and MS.
Channel Type
BCH :
Frequency Correction CHannel ( FCCH )-- for MS error correction
Synchronous Channel ( SCH)
-- for MS frame synchronization and BTS recognization
Broadcasting Control CHannel ( BCCH )-- broadcasting information(cell selection information, etc..)
Channel Type
DCCH
Self-help Dedicated Control Channel ( SDCCH )for channel distribution information transmission
Slow Associated Control Channel ( SACCH )combined with one traffic channel or SDCCH, to transmit some specific information of user information
Fast Associated Control Channel ( FACCH )combined with one traffic channel, taking the same signal as SDCCH. It occupies the service channel to transmit signaling information.
Structure of 51-frame Control CH
SF B C
R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R R
51 Frame
SF C C SF C C SF C C I
R R R R R R R R R R
D0 D1 D2 D3 D4 D5 D6 D7 A0 A1 A2 A3
SF C C
R R R R R R R R R R
III
D0 D1 D2 D3 D4 D5 D6 D7 A4 A5 A6 A7 III
A1 A2 A3 III
A5 A6 A7 III
D0 D1 D2 D3 D4 D5 D6 D7 A0
D0 D1 D2 D3 D4 D5 D6 D7 A4
SF B C SF C C SF D0 D1 SF D2 D3 ISF A0 A1
SF B C SF C C SF D0 D1 SF D2 D3 ISF A2 A3
D3
D3
R R
R R
A2 A3
A0 A1
D2
D2
SF
SF
D0 D1
D0 D1
R R R R R R R R R R R R R R R R R R R R R R R
R R R R R R R R R R R R R R R R R R R R R R R
F:FCCH S:SCHB:BCCH C:CCCH(CCCH=PCH+AGCH+RACH)R:RACH D:SDCCHA:SACCH/C I: idle
BCCH+CCCH(Downlink)
BCCH+CCCH(uplink)
8 SDCCH/8(Downlink)
8 SDCCH/8(uplink)
BCCH+CCCH+4SDCCH/4(Downlink)
BCCH+CCCH+4SDCCH/4
(uplink)
(a) FCCH+SCH+BCCH+CCCH
(b) SDCCH/8(0,...,7)+SACCH/C8(0,...,7)
(c) FCCH+SCH+CCCH+SDCCH/4(0,...,3)+SACCH/C4(0,...,3)
Channel Combination Type
Several logic channels combine together in some way to form some specific types of channel to transmit user data or signaling information. They are called combined channels. One combined channel can be mapped to a physical channel.
There are the following combined channels:a TCH/F + FACCH/F + SACCH/TFb TCH/H(0,1) + FACCH/H(0,1) + SACCH/TH(0,1)c TCH/H(0,0) + FACCH/H(0,1) + SACCH/TH(0,1) +
TCH/H(1,1)d FCCH + SCH + BCCH + CCCHe FCCH + SCH + BCCH + CCCH + SDCCH/4(0...3) +
SACCH/C4(0...3)f BCCH + CCCHg SDCCH/8(0 ..7) + SACCH/C8(0 .. 7)
CCCH = PCH + RACH + AGCH
• Small capacity cell with only 1 TRX
TN0: FCCH+SCH+CCCH+BCCH+SDCCH/4(0,_,3)+SACCH/C4(0,_,3);TN1-7: TCH/F+FACCH/F+SACCH/TF
• The medium-size cell with 4 TRXs1TN0 group: FCCH+SCH+BCCH+CCCH;
2 SDCCH/8(0,_,7)+SACCH/C8(0,_,7);29 TCH/F+FACCH/F+SACCH/TF
Channel Assignment inside cells
• Large-size cell with 12 TRXs1 TN0 group: FCCH+SCH+BCCH+CCCH;1 TN2 group, 1 TN4 group and 1 TN6 group: BCCH+CCCH;5 SDCCH/8(0,_,7)+SACCH/C8(0,_,7);87 TCH/F+FACCH/F+SACCH/TF
Channel Assignment inside cells
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
Cell Mode Layout
O
Omni-directional cell
Adopt omni-directional antenna ,the overall directional propagation characteristic is the same.
Directional cell
In general, cell with multi-sector is in common use. Every directional cell adopts directional antenna.
Capacity
When the traffic is very low, and no possibility for quick increment, Omni-directional cell is used in common. Otherwise, we suggest to adopt the sector cell.
Note: TRX-transceiver,each TRX handles 1 frequency.
Coverage AreaSector cell is often used to enlarge the cell coverage radius because of the higher antenna gain.For special coverage ,such as road coverage, two-sector cell is adopted firstly.
BTS Mode
Erlang :
the traffic intensity of a totally occupied channel (i.e. the call hour of a unit hour or the call minute of a unit minute). For example, the traffic of a channel occupied for 30 minutes in an hour is 0.5 Erlang)
GOS:
defined as the probability of call blocking or the probability when the call delay time is longer than a given queuing time.
System capacity
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
Reasons for interference
The transmission path is very complex, ranging from the simple line-of-sight transmission to encountering such terrain as buildings, hills and trees. Wireless channels are extremely unpredictable.
Abrupt drop, or fading, of signal strength in the land mobile wireless channel is quite common. The fading feature of the mobile channel depends on the radio wave propagation environment.
Reasons for interference
Environmental factors:
• Terrain (mountains, hills, plains, water bodies, etc.);
• The quantity, heights, distribution and materials of buildings;
• The vegetation of the region;
• Weather conditions;
• Natural and artificial electromagnetic noises;
• Frequency;
• How MS is moved.
Co-Channel Interference
Conception: the interference among the signals of co-
channel cells is called co-channel interference.
Result from :Frequency reuse
Reduction method:co-channel cells must physically be
spaced at a minimum interval to ensure adequate isolation of transmissions.
Interference
Adjacent Channel InterferenceConception:
The signal interference from the frequency adjacent to that of the signal used is called adjacent channel interference.
Reduction method: accurate filtering and channel allocation
(maximizing channel intervals of the cell). Interval of frequency reuse inter-cell interference, such as C/I, C/A
Interference
FH technology
Dynamic power control
(DPC)
Discontinuous Transceiving
(DTX)
Diversity receiving
technique
Solution --Anti-interference
Reason:• counteract Rayleigh Fading • scatter interference among multiple calls
Types: Base band frequency hopping
keeps the transmission and receiving frequency of each carrier unit unchanged, but merely sends FU transmission data to different carrier units at different FN moments.
radio frequency hoppingcontrols the frequency synthesizer of each transceiver, making it hop according to different schemes in different time slots.
Frequency Hopping Technique
Discontinuous Speech Transmission (DTX)
TRAU BTS
BTS MS
Speech frame
480 ms
comfort noise frame
Two aims can be achieved by adopting DTX mode:
•lower the total interference electric level in the air
•save transmitter power.
The multi-path propagation of radio signals causesmagnitude fading and delay time.
Space Diversity (antenna diversity)
Polarization Diversityorthogonal polarization diversity. horizontal polarization and vertical polarization.
Frequency DiversityThe working principle of this technology is that such fading won’t take place on the frequency outside the coherence bandwidth of the channel.
Diversity Reception Technology
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
“4 3” reuse mode: one group includes 3 sectors /site ,12 frequency which
are distributed to 4 sites. Every site owns 3 frequency.
Frequency Reuse
A3
D2B1
C3
B2D1
D3
A2C1
B3
C2A1
B3
C2A1
A3
A1B1
D1
D3D2
C3
B2A1
C3D2
C3
C1
D2B1C2A1
A2C1
D3
A3
C2B1
B3
A2C1
C3
B2A1
A3
C2B1
B3
A2C1
B3
A1C1
A1
A3A2
C3
B2A1
A3A3
C3
C1
B2A1B2A1
A2C1
B3
Frequency Reuse
“3 3” reuse mode: one group includes 3 sectors /site ,9 frequency which are
distributed to 3 sites. Every site owns 3 frequency.
Development of Mobile Communication
Basic Theory Network Architecture Functional Layer of GSM Air Interface System Capacity Anti Interference Technology Network Planning Numbering arrangement Security Management
Agenda
Numbering Arrangement
International mobile subscriber identification number (IMSI)
International mobile subscriber identification number (IMSI)
It identifies a unique international universal number of a mobile subscriber, which consists of MCC+MNC+MSIN.1) MCC: country code, 4602 ) MNC: network code, 00 or 013 ) MSIN: subscriber identification, H1H2H3H4 9XXXXXX, H1H2H3H4: subscriber registering place H1H2: assigned by the P&T Administrative Bureau (operator )to different provinces, to each province H3H4: assigned by each province/city
the IMSI of user will be written into the SIM card by specific device and software and be stored into the HLR with other user information.
It is the subscriber number commonly used. China uses the TDMA independent numbering plan:
CC+NDC+ H1H2H3H4 +ABC
CC: country code, 86NDC: network code, 135—139, 130H1H2H3H4: HLR identification code ABCD: mobile subscriber number inside each HLR
Mobile subscriber ISDN number ( MSISDN)Mobile subscriber ISDN number ( MSISDN)
Numbering Arrangement
International Mobile Equipment Identification code(IMEI)
International Mobile Equipment Identification code(IMEI)
It will uniquely identify a mobile station. It is a decimal number of 15 digits. Its structure is:
TAC+FAC+SNR+SP
TAC=model ratification code, 6 digitsFAC=factory assembling code, 2 digitsSNR=sequence code, 6 digitsSP=reserved, 1 digit
Numbering Arrangement
Mobile subscriber roaming number (MSRN)Mobile subscriber roaming number (MSRN)
The MSRN is temporarily distributed to the subscriber by the VLR according to the request by the HLR when this subscriber is called. The MSRN is released and can be assigned to other subscriber later.
CC + NDC + 00 + M1M2M3 + ABC CC: country code, 86 NDC: mobile network code, 135—139, 130 M1M2: same as the H2H3 of MSISDN ABC: 000 -- 999
Numbering Arrangement
Temporarily Mobile Subscriber Identification Number (TMSI)
Temporarily Mobile Subscriber Identification Number (TMSI)
To insure the IMSI security, the VLR will assign an unique TMSI number for the accessed subscriber. It is used locally only and is a 4-byte TMSI number BCD code.
Numbering Arrangement