gsm
DESCRIPTION
GSM PresentationTRANSCRIPT
SY1 V12.011981 NMT
NORWAY, DENMARK
FINLAND, SWEDEN,
There are several different types of analog cellular systems:
NMT450 and NMT900: Scandinavia, Benelux, Spain, Austria, France, Switzerland;
AMPS in more 34 countries: U.S.A., Canada, Argentine, Chile, Indonesia, Brazil, Australia, Republic of Congo (formerly Zaire);
TACS (Total Access Communication System) in UK Ireland and Italy;
R2000: France;
C450: Germany;
RTMS: Italy;
The world's first cellular system actually was implemented in 1979 by the Nippon Telephone and Telegraph company (NTT) in Japan. This system uses 600 FM duplex channels of 25 kHz in the 800 MHz band.
In Europe, the Nordic Mobile Telephone system (NMT) was developed in 1981 for the 450 MHz band and uses 180 channels of 25 kHz.
The extended European Total Access Cellular System (ETACS) was deployed in 1985 and is virtually identical to the US. AMPS system, except that the smaller bandwidth channels result in a slight degradation of signal-to-noise ratio and coverage range.
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30
40
50
60
70
80
90
100
120
140
160
180
200
240
3
4
5
6
7
8
9
10
12
14
16
18
20
24
Satellite
In the early years of radio, only the lowest few megahertz of the radio spectrum were in use and they were used for point to point communications between fixed stations, mainly ships, and broadcasting. These applications were respectively called the fixed service, the mobile service and the broadcasting service.
By international agreement, the spectrum then in use was divided into several frequency bands, different bands being allocated for each service.
This concept of dividing the spectrum between the different links of radio service is still found to be wise and its application has been extended and elaborated to serve modern requirements.
The international table of frequency allocations (World Radiocommunication Conference 1995) now covers the frequency range 9 kHz to 275 MHz, divided into hundreds of frequency bands, allocated for 33 different services.
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Uplink
Downlink
880
890
915
1710
1785
925
935
960
1805
1880
MHz
P-GSM
1850
1910
1930
1990
R-GSM
876
921
960
960
915
915
E-GSM
According to the resolution of the World Radiocommunication Conference in 1978, the European Telecom Authorities primarily reserved two frequency bands of twice 25 MHz:
890 MHz to 915 MHz from mobile to the network,
935 MHz to 960 MHz from base stations to the mobiles for use by cellular systems.
By 1990, a newly allocated band of twice 75 MHz (1710 MHz to 1785 MHz for uplink and 1805 MHz to 1880 MHz for downlink) was formed for the Digital Communication System which is a version of GSM suited to the 1800 MHz frequency band. This application was initiated in the United Kingdom.
Furthermore FCC has granted band of twice 60 MHz (1850 MHz to 1910 MHz for uplink and 1930 MHz to 1990 MHz for downlink) devoted to GSM networks.
Two new frequency bands are supported:
the Extended GSM 900 band or E-GSM = P-GSM + 2x10 MHz,
the Railway GSM 900 band for Railways companies or
R-GSM = E-GSM + 2x4 MHz.
BSS TO MSC INTERFACES
One important question was how far GSM should go in its specification work; that is, to what degree the system had to be specified so as to be identical in all countries, and how much could be left to the operators and suppliers to agree upon.
Clearly, without identical air interfaces in all networks, the subscribers are not going to have free roaming between network. This was considered to be the absolute minimum degree of standardization, and these equipment were favored. One might have seen it as advantageous to specify everything in the system, including the hardware and the mobile station and even other parts of the system. It was agreed upon that there would be no attempt to specify the system in such detail.
Basically, only the functional interfaces between the majors buildings blocks would be specified. This approach had several advantages, perhaps the most important of which is that for each major building block, the principle of functional specifications offers each operator, and thus the customer, the opportunity to purchase whatever make of equipment he wants, thus setting the stage for maximum competition between manufacturers. For instance the fact that an operator has purchased an exchange from a certain supplier does not force him to go on buying equipment from the same supplier.
Standardized electrical interfaces as well as protocols are provided for both the fixed network and subscriber equipment. These include standardized rate adaptations compatible with conventional ISDN (Integrated Services Digital Network) definitions.
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+
Calling line
0609225831
The GSM committee has introduced an important powerful innovation by using a Smart Card in conjunction with a mobile telephone. Thus GSM subscribers are provided with a Subscriber Identity Module card (SIM-Card) with its unique identification at the very beginning of the service.
The subscriber is identified within the system when he inserts the SIM-Card in the mobile equipment and switches it on. This provide a considerable amount of flexibility to the subscribers since they can use any GSM-specified mobile equipment.
With the SIM-Card the idea of "personal communication" is already realized: the user only needs to take his smart card on a trip. You can rent a mobile equipment unit at the destination, even in other country, and insert your own SIM-Card. Any call you make will be charged to your home GSM account. Also the GSM system is able to reach you at the mobile unit you are currently using.
The Mobile Station (MS) includes radio equipment and the man machine interface (MMI) that a subscriber needs in order to access the services provided by the GSM network.
Mobile Stations can be installed in vehicles or can be portable or hand-held stations.
The mobile station includes provisions for data communication as well as voice.
Mobile Stations transmit and receive messages to and from the GSM over the air interface to establish and continue connection through the system.
Each mobile station has an International Mobile Equipment Identity (IMEI) that is permanently stored in the mobile unit. Upon request, the MS sends this number over the signaling channel to the network. The IMEI is used to identify mobile units that are reported stolen or operating incorrectly.
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The Smart Card to use
The SIM-Card is a removable smart card, the size of a credit card, and contains an integrated circuit chip with a microprocessor, random access memory, and read-only memory.
Many MSs use the µ SIM-Card which can be snapped out of the credit card SIM, if required.
When a mobile users want to make a call, they insert their SIM-Card and provide their Personal Identity Number (PIN), which is compared with a PIN stored within the SIM-CARD.
The PIN can also be permanently bypassed by the subscribers if authorized by the service provider. Disabling the PIN code simplifies the call setup but reduces the protection of the user's account in the event of a stolen SIM-CARD.
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Similar to ISDN,
Conformity with E164/E213
but an operator
CC
NDC
SN
M1 M2 x x x x x x x x
Meaning
Mobile
Country
Code
Mobile
Network
Code
within the home PLMN
National Significant Mobile Number
The International Mobile Subscriber Identity (IMSI) is the primary identification of the subscriber within the GSM network and is permanently assigned to him.
The Mobile Subscriber ISDN Number (MSISDN) is the number that the calling party dials in order to reach the GSM subscriber. It is used by the land networks to route calls toward an appropriate GSM network. MSISDN is stored in HLR.
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Stored inside the Mobile Equipment.
Used to replace IMSI or TMSI when both are unavailable (example: Emergency calls without SIM-Card) or when required by the network (for maintenance).
Can be used for EIR database updating (when existing):
TAC = 6 digits describing the type of equipment,
FAC = 2 digits for identification of the factory,
SNR = 6 digits for the serial number of the device.
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BSC
MSC
BTS
OMC-R
OMC-S
MS
BSS
NSS
OSS
PSTN
A GSM system is basically designed as a combination of three major subsystems: the Network SubSystem (NSS), the radio subsystem called the Base station SubSystem (BSS), and the Operation SubSystem (OSS).
The Network SubSystem (NSS) includes the equipment and functions related to end-to-end-calls, management of subscribers, mobility, and interfaces with the fixed network (PSTN). It is built on the switch of the system called Mobile-services Switching Center (MSC).
The Base station SubSystem (BSS) includes the equipment and functions related to the management of the connection on the radio path. It mainly consists of Base Transceiver Stations (BTS) communicating with the Mobile Station (MS) and one Base Station Controller (BSC) managing the flow of information between the BTSs and the MSC.
The Operation SubSystem (OSS) mainly contains Operation and Maintenance Center for NSS (OMC-S) and Operation and Maintenance Center devoted to the BSS (OMC-R). It is connected to all equipment in the switching system and to the BSC (BTSs are not connected to the OSS).
Any mobile network or PLMN (Public Land Mobile Network) is related to a public fixed network, commonly to the PSTN (Public Switched Telephone Network).
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Teleservices cover regular telephony, emergency calls, voice messaging, and short messages handling.
The most important service provided by GSM users is telephony which enables bi-directional speech calls to be placed between GSM users and any telephone subscriber who is reachable through the general telephony network.
Fixed telephone subscribers worldwide as well as mobile network subscribers or subscribers of specific networks connected to a public telephone network can be reached.
Before either Mobile Originated or Mobile Terminated calls can be established, the mobile telephone must be switched on and registered into the system.
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while "112" is invoked
Card
To place an emergency call enter 112 followed by SEND. Additional means to place such call are also allowed by a dedicated button.
The Mobile Telephone supports the initiation of an emergency call without a SIM present in it, regardless of the call being accepted or not by the network.
Note that calls to national emergency services may be standard for the country of the serving GSM network (number 17 to call the police in France, number 911 to make an emergency call in U.S.A.).
However, with the exception of code "112", these are not treated within the GSM network as "teleservice emergency call" and would require a valid IMSI.
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GSM Network
message B
message B
message B
message B
message A
message A
message A
message A
Provider A
The cell broadcast enables an Information Provider to submit short messages for broadcasting to a specified area within the GSM network.
The cell broadcast service has the following features:
The cell broadcast message is sent (on control channels) in a limited area, defined by the originator of the message, by agreement with the GSM Operator.
The mobile telephone only receive the broadcast message in idle mode.
The short message function running in the mobile is able not to store broadcast messages which are not wanted or which have already been received.
The mobile telephone does not send acknowledgment.
The GSM network continuously sends cell broadcast messages so that all such messages are sent in turn, an then repeated. On the other hand, the cycle time is short enough for important messages to be received by travelers (subscribers) moving through a group of cells.
The maximum length of each cell broadcast message will be 93 characters and GSM specifications allows up to 15 of these 93 character messages treated as segment of a longer message.
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Radio
PLMN
Short Message Service (SMS) allows the point to point transmission of a short message to/from MS, using their IMSI.
A short message is an alphanumeric string that can be up to 160 characters long (140 octets).
Two different types of short message are defined:
short message MT/PP (Mobile Terminated / Point to Point),
short message MO/PP (Mobile Originated / Point to Point).
Point to point messages may be sent or received when the MS is engaged on a call (voice or data), or in idle mode.
However, messages which overlap the boundary of such a call, or during a handover, may be lost, in which case they will be sent again.
Messages may be input to the SC from a fixed network customer by means of a suitable telecommunication service either from the fixed network or from a mobile network customer.
An acknowledgment indicates that the GSM Network has successfully transferred the message to the mobile telephone or the SC.
Optionally, the SC may offer final delivery notification to the originator. This delivery report indicates whether this particular message has been correctly received at the receiving station or not, to the extent that the SC is able to establish this.
It does not indicate whether the message has been read. If the delivery report is negative, it includes the failure cause. The delivery report is sent to the originator, if reachable, as soon as the information is available.
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Automatic fax:
Fax transmissions are possible via a PLMN only with a Fax-group3 (14.4 kbps).
Two modes are available:
manual mode allows to switch alternatively from voice transmission to fax transmission,
automatic mode allows to send and receive a fax without any human intervention; however, voice transmission is impossible in this mode.
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Teleservices
voice
Teleservices
treatments for
radio transmission
Data / Fax
kit adaptation
Connections can be made with a suitable data/fax kit adaptation either to other Mobile Station or to other data users on circuit-switched (PSTN).
The slide gives an example of a suitable data/fax kit and a computer that are directly connected to the MS.
In the case of making a Fax-call to a PSTN subscriber, the GSM network automatically selects the suitable modem for the link to the similar modem at the remote end.
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messages
Voice
message
server
1
Another service derived from telephony is voice messaging. Many operators offer it as a basic feature.
It enables a voice message to be stored for later retrieval by the mobile recipient, either because he was not reachable at time of the call or because the calling party choose to access the voice mailbox of the GSM subscriber directly.
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CLIP
CoLR
Calling line identification presentation (CLIP) provides the ability to indicate the ISDN number of the calling party with possible additional address information to the called party. This identity is provided to the called subscriber before answering, thus enabling him to make the decision of whether to take the call or not.
Calling line identification restriction (CLIR) enables the calling party not to send any address information to the called party.
Connected line identification presentation (CoLP) provides the GSM caller with the phone number he has reached.
Connected line identification restriction (CoLR) enables the called party not to send its phone number to the calling party.
Calling Name Presentation (CNAP) provides the calling party name instead of the ISDN number. However, this service is not yet specified by GSM recommendations.
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unconditional (CFU)
1
2
Call forwarding unconditional (CFU) allows a called mobile subscriber to have the network send all incoming calls, which are addressed to the called mobile subscriber’s directory number, to another directory number.
Call forwarding on mobile subscriber busy (CFB): allows a called mobile subscriber to have the network send the incoming calls, which are addressed to the called mobile subscriber’s directory number and which meet mobile subscriber busy, definition to another directory number.
Call forwarding on no reply (CFNRy) allows an called mobile subscriber to have the network send the incoming calls, which are addressed to the subscriber’s directory number and which meet no reply, to another directory number.
Call forwarding on MS not reachable (CFNRc) provides for a mobile subscriber to have the network send all incoming calls, which are addressed to the called mobile directory number and meet the not reachable definition, to another directory number.
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1
2
HOLD
1
2
WAIT
1
2
1
2
Call waiting (CW): provides a mobile subscriber with the possibility of being notified of an incoming call while his mobile telephone is in the busy state. Subsequently, the user can either answer, reject, or ignore the incoming call. Both the call waiting and call hold (described further) options are the same as those offered by the PSTN.
Call Hold (HOLD): allows a served mobile subscriber to interrupt communication on an existing call and then subsequently, if desired, to reestablish communication.
Multi party service (MPTY):
This Supplementary Service provides a mobile subscriber with the ability to have a multi-connection call, in other words a simultaneous communication with more than one party.
A precondition for the multi-party service is that the served mobile subscriber is in control of one active call and one call on hold, both calls having been answered. In this situation the served mobile subscriber can request the network to begin the multiParty service.
Once a multiParty call is active, remote parties may be added, disconnected or separated (i.e.. removed from the multiParty call but remain connected to the served mobile subscriber).
The maximum number of remote parties is 5.
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Incoming (BAIC)
(BIC-Roam)
Barring of all outgoing call (BAOC): makes it possible for a mobile subscriber to prevent all outgoing calls.
Barring outgoing international calls (BOIC): allows a mobile subscriber to prevent all attempted outgoing calls.
BOIC except those directed to the home PLMN country (BOIC-exHC)
Barring of all incoming international (BAIC).
Barring of all incoming calls when roaming outside the home GSM network country (BIC-Roam): makes it possible for a mobile subscriber to prevent all incoming calls that would otherwise be terminated at his directory number. This only applies to the case when the mobile subscriber roams outside his home GSM network.
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Idle
Ring !
Ring !
2
1
NEW!
Completion of calls to busy subscribers (CCBS): allows a calling mobile subscriber who encounters a busy called subscriber to be notified by the system operator when the busy called subscriber becomes free and have the operator re-initiate the call if the caller so desires.
This feature has to be supported by both the originating and the terminating networks.
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Completion of call
Advice of Charge Information (AoCI)
Advice of Charge Charging (AoCC)
Advice of charge Information (AoCI): informs the user of the real-time information on progress of the cost of the call.
Advice of charge Charging (AoCC): the mobile may be a money-operated mobile telephone or a standard mobile station that can display the charging information and can accept either coins or charge a credit-card.
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Intelligent Network Services
IN and CAMEL
The aim of the CAMEL (Customized Application for Mobile network Enhanced Logic) is to provide GSM network operators with the ability to create specific services in their home network, and export these services to their subscribers when roaming outside the home network.
CAMEL introduces the ability to provide location dependent IN type of services to mobiles subscribers.
Main IN Services:
The Intelligent Network or IN is a switching network concept.
Its idea is to make GSM services system an open system; that is to say new services modules can always be added on the previous system without changing its architecture.
Basic call processing is performed by the switch and when it recognizes that a call requires an IN service, this service processing is provided by another entity, located either…
NORWAY, DENMARK
FINLAND, SWEDEN,
There are several different types of analog cellular systems:
NMT450 and NMT900: Scandinavia, Benelux, Spain, Austria, France, Switzerland;
AMPS in more 34 countries: U.S.A., Canada, Argentine, Chile, Indonesia, Brazil, Australia, Republic of Congo (formerly Zaire);
TACS (Total Access Communication System) in UK Ireland and Italy;
R2000: France;
C450: Germany;
RTMS: Italy;
The world's first cellular system actually was implemented in 1979 by the Nippon Telephone and Telegraph company (NTT) in Japan. This system uses 600 FM duplex channels of 25 kHz in the 800 MHz band.
In Europe, the Nordic Mobile Telephone system (NMT) was developed in 1981 for the 450 MHz band and uses 180 channels of 25 kHz.
The extended European Total Access Cellular System (ETACS) was deployed in 1985 and is virtually identical to the US. AMPS system, except that the smaller bandwidth channels result in a slight degradation of signal-to-noise ratio and coverage range.
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30
40
50
60
70
80
90
100
120
140
160
180
200
240
3
4
5
6
7
8
9
10
12
14
16
18
20
24
Satellite
In the early years of radio, only the lowest few megahertz of the radio spectrum were in use and they were used for point to point communications between fixed stations, mainly ships, and broadcasting. These applications were respectively called the fixed service, the mobile service and the broadcasting service.
By international agreement, the spectrum then in use was divided into several frequency bands, different bands being allocated for each service.
This concept of dividing the spectrum between the different links of radio service is still found to be wise and its application has been extended and elaborated to serve modern requirements.
The international table of frequency allocations (World Radiocommunication Conference 1995) now covers the frequency range 9 kHz to 275 MHz, divided into hundreds of frequency bands, allocated for 33 different services.
slide-*
TE474-
Uplink
Downlink
880
890
915
1710
1785
925
935
960
1805
1880
MHz
P-GSM
1850
1910
1930
1990
R-GSM
876
921
960
960
915
915
E-GSM
According to the resolution of the World Radiocommunication Conference in 1978, the European Telecom Authorities primarily reserved two frequency bands of twice 25 MHz:
890 MHz to 915 MHz from mobile to the network,
935 MHz to 960 MHz from base stations to the mobiles for use by cellular systems.
By 1990, a newly allocated band of twice 75 MHz (1710 MHz to 1785 MHz for uplink and 1805 MHz to 1880 MHz for downlink) was formed for the Digital Communication System which is a version of GSM suited to the 1800 MHz frequency band. This application was initiated in the United Kingdom.
Furthermore FCC has granted band of twice 60 MHz (1850 MHz to 1910 MHz for uplink and 1930 MHz to 1990 MHz for downlink) devoted to GSM networks.
Two new frequency bands are supported:
the Extended GSM 900 band or E-GSM = P-GSM + 2x10 MHz,
the Railway GSM 900 band for Railways companies or
R-GSM = E-GSM + 2x4 MHz.
BSS TO MSC INTERFACES
One important question was how far GSM should go in its specification work; that is, to what degree the system had to be specified so as to be identical in all countries, and how much could be left to the operators and suppliers to agree upon.
Clearly, without identical air interfaces in all networks, the subscribers are not going to have free roaming between network. This was considered to be the absolute minimum degree of standardization, and these equipment were favored. One might have seen it as advantageous to specify everything in the system, including the hardware and the mobile station and even other parts of the system. It was agreed upon that there would be no attempt to specify the system in such detail.
Basically, only the functional interfaces between the majors buildings blocks would be specified. This approach had several advantages, perhaps the most important of which is that for each major building block, the principle of functional specifications offers each operator, and thus the customer, the opportunity to purchase whatever make of equipment he wants, thus setting the stage for maximum competition between manufacturers. For instance the fact that an operator has purchased an exchange from a certain supplier does not force him to go on buying equipment from the same supplier.
Standardized electrical interfaces as well as protocols are provided for both the fixed network and subscriber equipment. These include standardized rate adaptations compatible with conventional ISDN (Integrated Services Digital Network) definitions.
slide-*
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+
Calling line
0609225831
The GSM committee has introduced an important powerful innovation by using a Smart Card in conjunction with a mobile telephone. Thus GSM subscribers are provided with a Subscriber Identity Module card (SIM-Card) with its unique identification at the very beginning of the service.
The subscriber is identified within the system when he inserts the SIM-Card in the mobile equipment and switches it on. This provide a considerable amount of flexibility to the subscribers since they can use any GSM-specified mobile equipment.
With the SIM-Card the idea of "personal communication" is already realized: the user only needs to take his smart card on a trip. You can rent a mobile equipment unit at the destination, even in other country, and insert your own SIM-Card. Any call you make will be charged to your home GSM account. Also the GSM system is able to reach you at the mobile unit you are currently using.
The Mobile Station (MS) includes radio equipment and the man machine interface (MMI) that a subscriber needs in order to access the services provided by the GSM network.
Mobile Stations can be installed in vehicles or can be portable or hand-held stations.
The mobile station includes provisions for data communication as well as voice.
Mobile Stations transmit and receive messages to and from the GSM over the air interface to establish and continue connection through the system.
Each mobile station has an International Mobile Equipment Identity (IMEI) that is permanently stored in the mobile unit. Upon request, the MS sends this number over the signaling channel to the network. The IMEI is used to identify mobile units that are reported stolen or operating incorrectly.
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The Smart Card to use
The SIM-Card is a removable smart card, the size of a credit card, and contains an integrated circuit chip with a microprocessor, random access memory, and read-only memory.
Many MSs use the µ SIM-Card which can be snapped out of the credit card SIM, if required.
When a mobile users want to make a call, they insert their SIM-Card and provide their Personal Identity Number (PIN), which is compared with a PIN stored within the SIM-CARD.
The PIN can also be permanently bypassed by the subscribers if authorized by the service provider. Disabling the PIN code simplifies the call setup but reduces the protection of the user's account in the event of a stolen SIM-CARD.
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Similar to ISDN,
Conformity with E164/E213
but an operator
CC
NDC
SN
M1 M2 x x x x x x x x
Meaning
Mobile
Country
Code
Mobile
Network
Code
within the home PLMN
National Significant Mobile Number
The International Mobile Subscriber Identity (IMSI) is the primary identification of the subscriber within the GSM network and is permanently assigned to him.
The Mobile Subscriber ISDN Number (MSISDN) is the number that the calling party dials in order to reach the GSM subscriber. It is used by the land networks to route calls toward an appropriate GSM network. MSISDN is stored in HLR.
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Stored inside the Mobile Equipment.
Used to replace IMSI or TMSI when both are unavailable (example: Emergency calls without SIM-Card) or when required by the network (for maintenance).
Can be used for EIR database updating (when existing):
TAC = 6 digits describing the type of equipment,
FAC = 2 digits for identification of the factory,
SNR = 6 digits for the serial number of the device.
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BSC
MSC
BTS
OMC-R
OMC-S
MS
BSS
NSS
OSS
PSTN
A GSM system is basically designed as a combination of three major subsystems: the Network SubSystem (NSS), the radio subsystem called the Base station SubSystem (BSS), and the Operation SubSystem (OSS).
The Network SubSystem (NSS) includes the equipment and functions related to end-to-end-calls, management of subscribers, mobility, and interfaces with the fixed network (PSTN). It is built on the switch of the system called Mobile-services Switching Center (MSC).
The Base station SubSystem (BSS) includes the equipment and functions related to the management of the connection on the radio path. It mainly consists of Base Transceiver Stations (BTS) communicating with the Mobile Station (MS) and one Base Station Controller (BSC) managing the flow of information between the BTSs and the MSC.
The Operation SubSystem (OSS) mainly contains Operation and Maintenance Center for NSS (OMC-S) and Operation and Maintenance Center devoted to the BSS (OMC-R). It is connected to all equipment in the switching system and to the BSC (BTSs are not connected to the OSS).
Any mobile network or PLMN (Public Land Mobile Network) is related to a public fixed network, commonly to the PSTN (Public Switched Telephone Network).
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Teleservices cover regular telephony, emergency calls, voice messaging, and short messages handling.
The most important service provided by GSM users is telephony which enables bi-directional speech calls to be placed between GSM users and any telephone subscriber who is reachable through the general telephony network.
Fixed telephone subscribers worldwide as well as mobile network subscribers or subscribers of specific networks connected to a public telephone network can be reached.
Before either Mobile Originated or Mobile Terminated calls can be established, the mobile telephone must be switched on and registered into the system.
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while "112" is invoked
Card
To place an emergency call enter 112 followed by SEND. Additional means to place such call are also allowed by a dedicated button.
The Mobile Telephone supports the initiation of an emergency call without a SIM present in it, regardless of the call being accepted or not by the network.
Note that calls to national emergency services may be standard for the country of the serving GSM network (number 17 to call the police in France, number 911 to make an emergency call in U.S.A.).
However, with the exception of code "112", these are not treated within the GSM network as "teleservice emergency call" and would require a valid IMSI.
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GSM Network
message B
message B
message B
message B
message A
message A
message A
message A
Provider A
The cell broadcast enables an Information Provider to submit short messages for broadcasting to a specified area within the GSM network.
The cell broadcast service has the following features:
The cell broadcast message is sent (on control channels) in a limited area, defined by the originator of the message, by agreement with the GSM Operator.
The mobile telephone only receive the broadcast message in idle mode.
The short message function running in the mobile is able not to store broadcast messages which are not wanted or which have already been received.
The mobile telephone does not send acknowledgment.
The GSM network continuously sends cell broadcast messages so that all such messages are sent in turn, an then repeated. On the other hand, the cycle time is short enough for important messages to be received by travelers (subscribers) moving through a group of cells.
The maximum length of each cell broadcast message will be 93 characters and GSM specifications allows up to 15 of these 93 character messages treated as segment of a longer message.
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Radio
PLMN
Short Message Service (SMS) allows the point to point transmission of a short message to/from MS, using their IMSI.
A short message is an alphanumeric string that can be up to 160 characters long (140 octets).
Two different types of short message are defined:
short message MT/PP (Mobile Terminated / Point to Point),
short message MO/PP (Mobile Originated / Point to Point).
Point to point messages may be sent or received when the MS is engaged on a call (voice or data), or in idle mode.
However, messages which overlap the boundary of such a call, or during a handover, may be lost, in which case they will be sent again.
Messages may be input to the SC from a fixed network customer by means of a suitable telecommunication service either from the fixed network or from a mobile network customer.
An acknowledgment indicates that the GSM Network has successfully transferred the message to the mobile telephone or the SC.
Optionally, the SC may offer final delivery notification to the originator. This delivery report indicates whether this particular message has been correctly received at the receiving station or not, to the extent that the SC is able to establish this.
It does not indicate whether the message has been read. If the delivery report is negative, it includes the failure cause. The delivery report is sent to the originator, if reachable, as soon as the information is available.
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Automatic fax:
Fax transmissions are possible via a PLMN only with a Fax-group3 (14.4 kbps).
Two modes are available:
manual mode allows to switch alternatively from voice transmission to fax transmission,
automatic mode allows to send and receive a fax without any human intervention; however, voice transmission is impossible in this mode.
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Teleservices
voice
Teleservices
treatments for
radio transmission
Data / Fax
kit adaptation
Connections can be made with a suitable data/fax kit adaptation either to other Mobile Station or to other data users on circuit-switched (PSTN).
The slide gives an example of a suitable data/fax kit and a computer that are directly connected to the MS.
In the case of making a Fax-call to a PSTN subscriber, the GSM network automatically selects the suitable modem for the link to the similar modem at the remote end.
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messages
Voice
message
server
1
Another service derived from telephony is voice messaging. Many operators offer it as a basic feature.
It enables a voice message to be stored for later retrieval by the mobile recipient, either because he was not reachable at time of the call or because the calling party choose to access the voice mailbox of the GSM subscriber directly.
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CLIP
CoLR
Calling line identification presentation (CLIP) provides the ability to indicate the ISDN number of the calling party with possible additional address information to the called party. This identity is provided to the called subscriber before answering, thus enabling him to make the decision of whether to take the call or not.
Calling line identification restriction (CLIR) enables the calling party not to send any address information to the called party.
Connected line identification presentation (CoLP) provides the GSM caller with the phone number he has reached.
Connected line identification restriction (CoLR) enables the called party not to send its phone number to the calling party.
Calling Name Presentation (CNAP) provides the calling party name instead of the ISDN number. However, this service is not yet specified by GSM recommendations.
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unconditional (CFU)
1
2
Call forwarding unconditional (CFU) allows a called mobile subscriber to have the network send all incoming calls, which are addressed to the called mobile subscriber’s directory number, to another directory number.
Call forwarding on mobile subscriber busy (CFB): allows a called mobile subscriber to have the network send the incoming calls, which are addressed to the called mobile subscriber’s directory number and which meet mobile subscriber busy, definition to another directory number.
Call forwarding on no reply (CFNRy) allows an called mobile subscriber to have the network send the incoming calls, which are addressed to the subscriber’s directory number and which meet no reply, to another directory number.
Call forwarding on MS not reachable (CFNRc) provides for a mobile subscriber to have the network send all incoming calls, which are addressed to the called mobile directory number and meet the not reachable definition, to another directory number.
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1
2
HOLD
1
2
WAIT
1
2
1
2
Call waiting (CW): provides a mobile subscriber with the possibility of being notified of an incoming call while his mobile telephone is in the busy state. Subsequently, the user can either answer, reject, or ignore the incoming call. Both the call waiting and call hold (described further) options are the same as those offered by the PSTN.
Call Hold (HOLD): allows a served mobile subscriber to interrupt communication on an existing call and then subsequently, if desired, to reestablish communication.
Multi party service (MPTY):
This Supplementary Service provides a mobile subscriber with the ability to have a multi-connection call, in other words a simultaneous communication with more than one party.
A precondition for the multi-party service is that the served mobile subscriber is in control of one active call and one call on hold, both calls having been answered. In this situation the served mobile subscriber can request the network to begin the multiParty service.
Once a multiParty call is active, remote parties may be added, disconnected or separated (i.e.. removed from the multiParty call but remain connected to the served mobile subscriber).
The maximum number of remote parties is 5.
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Incoming (BAIC)
(BIC-Roam)
Barring of all outgoing call (BAOC): makes it possible for a mobile subscriber to prevent all outgoing calls.
Barring outgoing international calls (BOIC): allows a mobile subscriber to prevent all attempted outgoing calls.
BOIC except those directed to the home PLMN country (BOIC-exHC)
Barring of all incoming international (BAIC).
Barring of all incoming calls when roaming outside the home GSM network country (BIC-Roam): makes it possible for a mobile subscriber to prevent all incoming calls that would otherwise be terminated at his directory number. This only applies to the case when the mobile subscriber roams outside his home GSM network.
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Idle
Ring !
Ring !
2
1
NEW!
Completion of calls to busy subscribers (CCBS): allows a calling mobile subscriber who encounters a busy called subscriber to be notified by the system operator when the busy called subscriber becomes free and have the operator re-initiate the call if the caller so desires.
This feature has to be supported by both the originating and the terminating networks.
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Completion of call
Advice of Charge Information (AoCI)
Advice of Charge Charging (AoCC)
Advice of charge Information (AoCI): informs the user of the real-time information on progress of the cost of the call.
Advice of charge Charging (AoCC): the mobile may be a money-operated mobile telephone or a standard mobile station that can display the charging information and can accept either coins or charge a credit-card.
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Intelligent Network Services
IN and CAMEL
The aim of the CAMEL (Customized Application for Mobile network Enhanced Logic) is to provide GSM network operators with the ability to create specific services in their home network, and export these services to their subscribers when roaming outside the home network.
CAMEL introduces the ability to provide location dependent IN type of services to mobiles subscribers.
Main IN Services:
The Intelligent Network or IN is a switching network concept.
Its idea is to make GSM services system an open system; that is to say new services modules can always be added on the previous system without changing its architecture.
Basic call processing is performed by the switch and when it recognizes that a call requires an IN service, this service processing is provided by another entity, located either…