mc final practical

8/8/2019 Mc Final Practical

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BTS

BTS

BTS

EXPERIMENT: - 1

AIM: - Introduction to GSM Trainer Modules.

Block Diagram of GSM

D

VLR HLR/AC PSTN

G B

C

VLR E

MSC MSC

F

A

Abis

EIR BSC

Um

BSC = Base Station ControllerBTS = Base Trasreceiver Station

MSC = Mobile Switching Center

HLR = Home Location Register

VLR = Visitor Location RegisterEIR = Eqipment Identity Register

AC = Authentication Center

Fig.- Reference architecture and signaling interfaces for GSM

Vishwakarma Government Engineering College, Chandkheda 1


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Radio parameters and characteristics for GSM:

System parameter value (GSM)

Multiple access : TDMA/FDMA/FDD

Uplink frequency(mobile to base) : 890-915 MHZDownlink frequency(base to mobile) : 935-960 MHZ

Channel bandwidth : 200 KHZ

Number of channels : 124Channels/carrier : 8 (full rate), 16 (half rate)

Frame duration : 4.6 ms

Interleaving duration : 40 ms

Modulation : GMSK Speech coding method : RPE-LTE convolution

Speech coder bit rate : 13 kbps (full rate)

Associated control channel : Extra frame

Handoff scheme : Mobile assistedMobile station power levels : 0.8,2.5,8 W

1) Used abbreviations

ETSI European Telecommunications Standards Institute

GSM Global System for Mobile Communications

IMEI International Mobile station Equipment Identity

ME Mobile Equipment

PLMN Public Land Mobile Network

PIN Personal Identification Number

PUKPersonal Unblocking Key

RP Receive Protocol

RXQUAL Received Signal Quality

SIM Subscriber Identity Module

SMS Short Message Service

SMS/PP Short Message Service/Point-to-Point

TA Terminal Adapter

TE Terminal Equipment

TP Transmit Protocol

Important For The Efficient And Safe Operation Of Your Gsm Modem Read This

Information Before Use!

Your GSM modem is one of the most exciting and innovative electronics productsever developed. With it you can stay in contact with your office, your home, emergency

services and others, wherever service is provided.

General

Your modem utilizes the GSM standard for cellular technology. GSM is a newer

radio frequency technology than the current FM technology that has been used for radio

communication for decades. The GSM standard has been established for use in the



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European community and elsewhere. Your modem is actually a low power radio

transmitter and receiver. It sends out and receives radio frequency energy. When you use

your modem, the cellular system handling your calls controls both the radio frequencyand the power level of your cellular modem.

Exposure to RF EnergyThere has been some public concern about possible health effects of using GSM

modem. Although research on health effects from RF energy has focused for many years

on the current RF technology, scientists have begun research regarding newer radiotechnologies, such as GSM. After tested, it has been concluded that the product is fit for

use. If you are concerned about exposure to RF energy there are things you can do to

minimize exposure. Obviously, limiting the duration of your calls will reduce your

exposure to RF energy. In addition, you can reduce RF exposure by operating yourcellular modem efficiently by following the below guidelines.

For your modem to operate at the lowest power level, consistent with satisfactory

call quality. If your modem has an extendible antenna, extend it fully. Some models

allow you to place a call with the antenna retracted. However your modem operate moreefficiently with the antenna fully extended.

Do not hold the antenna when the modem is IN USE. Holding the antennaaffects call quality and may cause the modem to operate at a higher power level than

needed.

Antenna Care and Replacement

Do not use the modem with a damaged antenna. If a damaged antenna comes into

contact with the skin, a minor burn may results. Replace a damaged antenna immediately.

Consult your manual to see if you may change the antenna yourself. If so, use only amanufacturer approved antenna. Otherwise, have your antenna repaired by a qualified

technician. Use only the supplied or approved antenna. Unauthorized antennas,

modifications or attachments could damage the modem and may contravene local RFemission regulations or invalidate type approval.

Electronic Devices

Most electronic equipment, for example in hospitals and motor vehicles is

shielded from RF energy. However RF energy may affect some malfunctioning or

improperly shielded electronic equipment.



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EXPERIMENT: -2

AIM: - Study the AT Command.

These commands are working

Serial link control commands

2.1 ATE

The setting of this parameter determines whether or not the DCE echoes charactersreceived from the DTE during command state and online command state.

Command Possible Responses

E[] OK

Defined values:

: 0 DCE does not echo characters during command state and online

command state . 1 DCE does not echo characters during command state and

online command state.

Remarks: NoneSource: V.25ter/6.2.4

Implementation: Complete

2.2 ATQ

The setting of this parameter determines whether or not the DCE transmits result codes tothe DTE. When result codes are being suppressed, no portion of any intermediate, final or

unsolicited result code-header, result text, line terminator, or trailer is transmitted,

Information text transmited in response to commands is not affected by the setting of this

parameter.


Q[] OK Defined values:

: 0 DCE transmit result codes.

1 result codes are suppressed and not transmitted.

Remarks: None

Source: V.25ter/6.2.5v


2.3 ATV

The setting of this parameter determines the contents of the header and trailer transmitted

with result codes and information responses. It also determines whether result codes are

transmitted in a numeric form or an alphabetic (or verbose) form. The text portion ofinformation responses is not affected by this setting.


V[] OK

Defined values:

: 0 DCE transmits limited headers and trailers and numeric text..

1 DCE transmits full headers and trailers and verbose response text.

Remarks: None



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Source: V.25ter/6.2.6


2.4 AT&C

This parameter determines how the state of circuit 109 (DCD) relates to the detection of

received line signal from the distant end.

Command Possible Responses&C[] OK

Defined values:

: 0 DCD always on.1 DCD matches the state of the remote modems data carrier.

Remarks: None



2.5 AT&D

This parameter determines how the DCE responds when circuit 108/2 (DTR) is changed

from the ON to the OFF condition during online data state.Command Possible Responses&D[] OK &D?

Defined values:

: 0 DTR is ignored.

1Upon an on-to-off transition of DTR, the DCE enters online commandstate and

issues an OK result code, the call remains connected.

2 1Upon an on-to-off transition of DTR, the DCE instructs the underlyingDCE to

perform an orderly clear-down of the call.

Remarks: None



2.6 AT&S

This parameter controls the DSR (Data Set Ready ) signal.


&S[] OK

Defined values:

: 0 DCR is always on.

1 DCR off in command mode, on in online mode.

Remarks: None

Source: factory default


2.7 AT+IPR

This numeric extended-format parameter specifies the data rate at which the DCE will

accept commands.



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+IPR= OK

+IPR? +IPR: +IPR=?+IPR: [List of auto-bauding-capable values ], [List of fixed only

values]

Defined values::Value specified shall be the rate in bits per second.

A value of 0 switches into auto-bauding mode.

Remarks: The auto-bauding mode needs to have the characters in capital letters,otherwise they could not be recognized.



Call control commands

2.8 ATD

Command is used to establish a voice call.Command Possible Responses

ATD; OK if call is established

BUSY if called party is another callNO ANSWER if called party does not accept a call

NO CARRIER If there are problems to establish a call

Defined values:

: Telephone number to dial.

Remarks: in caseof international number, the local international prefix (usually 00)

could be replaced by the + character. For phonebook dialing please see phonebook

command section.

Source: GSM 07.07/V.25ter/6.3.1Implementation: Complete

2.9 AT+VTD

Command is used to set the length of DTMF tones emitted.


AT+VTD= OK

AT+VTD? +VTD:

AT+VTD=? (list of supported s)

Defined values:

Tone of duration *100 milliseconds.

Remarks: If n< 4 the tone duration is 300ms.Source: GSM 07.07/C.12


2.10 ATDL

Command is used to redial the last dialed number.


ATDL CONNECT If data call is established



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OK If voice call is established

BUSY If called party is in another call

NO ANSWER If called party does not accept a callNO CARRIER If there are problems to establish a call

Defined values:

: Lin baud rate between modem and network.

Remarks: Command uses the same type of connection (voice or data) as the last

dialed connection.

Source: Factory default


2.11 ATA

Command is used to accept an incoming call.


ATA OK If incoming call is a voice call

CONNECT If incoming call is a data call ERRORDefined values: See ATD command.

Remarks: User should use command only if ATS0 equals zero.

Source: GSM 07.07/V.25ter/6.3.5


2.12 AT+CBST

Command is used to select the bearer service type and the transparent or non-transparent

mode for a data connection.


+CBST=[,0,[,]] OK

AT+CBST? + CBST=,0,AT+CBST=? +CBST: (list of supported s),0,(list of

supporteds)

Defined values:

: 0 Auto bauding (automatic selection of the speed)

1 300 bps (V.21)

2 1200 bps (V.22)

4 2400 bps (V.22bis)6 4800 bps (V.32)

7 9600 bps (V.32)

8 specific12 9600 bps (V.34)

14 14400 bps (V.34)

65 300 bps (V.110)66 1200 bps (V.110)

68 2400 bps (V.110)

70 4800 bps (V.110)

71 9600 bps (V.110)



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75 14400 bps (V.110)

: 0 Transparent

1 non-transparent2 Transparent preferred

3 Non-Transparent preferred

Remarks: NoneSource: GSM 07.07/6.7


2.13 AT\N

This command controls the preferred errr correcting mode in a data connection. It can

only be used for transparent data transmission.

If V42 feature is provided, the module authorizes the LAPM error correction mode.If MNP2 feature is provided, the module authorizes the MNP error correction mode


AT\N OKl

AT\N?Defined values: 0 Disables error correction mode

2 Selects an auto reliable mode (LAOM connection, then MNP connection)

4 Selects LAPM error correction mode

5 Selects MNP error correction mode

Remarks: 2 and 4 are not implemented up to now.



2.14 AT+CR

Command controls whether or not intermediate result code +CCR: is returnedfrom the modem during connect negotiation of a call.


+CR=[] OK AT+CR?+CR

AT+CR=? +CR: (list of s)

Defined values:

: 0 Disables reporting1 enables reporting

: ASYNC Asynchronous transparent

RELASYNC Asynchronous non-transparent

Remarks: None

Source: GSM 07.07/6.9


Call information commands



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0 Disable

1 Enable

2 Query statuses: is a sum of integers each representing a class of information (default 7

equals to all classes):

1 Voice2 Data

4 Fax

: 0 Not active1 Active

Remarks: None



2.18 AT+CLIP

Command is used to set and request the status of the calling line identification

presentation service depending on the setting the calling party will be shown as resultcode +CLIP , on incoming call (after every RING)


+CLIP=[] OK

AT+CLIP? +CLIP=,

AT+CLIP=? +CLIP :( list of supported s)

Defined values:

(parameter sets/show the result code presentation status):

0 Disable

1 enables (parameter shows the subscriber CLIP service status in the

network):

0 CLIP not provisioned1 CLIP provisioned

2 Unknown (e.g. no network, etc.)

string type phone number of format specified by . Type of address octet in integer formate.

Remarks: None



2.19 AT+CLIR

Command is used to set and request the status of the calling line identification restriction

service

Depending on the setting the own number is presented to the called party or not


+CLIR=[] OK

AT+CLIR? +CLIR=,

AT+CLIR=? +CLIR :( list of supported s)



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Defined values:

(parameter sets the adjustment for outgoing calls):0 presentation indicators is used according to the subscription of

the CLIR

service (as with the SIM card contract)1 CLIR invocation (number will not be transmitted)

2 CLIR suppression (number will be transmitted)

(parameter shows the subscriber CLIP service status in thenetwork):

0 CLIP not provisioned

1 CLIP provisioned

2 Unknown (e.g. no network, etc.)3 CLIR temporary mode presentation restricated

4 CLIR temporary mode presentations allowed

Remarks: None

Source: GSM 07.07/7.7Implementation: Complete

2.20 AT+COLP[0]

Command is used to set and request the status of the connected line identification

presentation depending on the number of the called party will be shown as result code

+COLP: , on outgoing calls.


+COLP=[] OK

AT+COLP? +COLP=, AT+COLP=? +COLP :( list of supported s)

Defined values:

(parameter sets/show the result code presentation status):

0 Disable

1 enables (parameter shows the subscriber CLIP service status in the

network):

0 CLIP not provisioned

1 CLIP provisioned2 Unknown (e.g. no network, etc.)

: string type phone number of format specified by .

Type of address octet in integer formate.

Remarks: not available in most networks





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2.21 AT+CPBS

Command select phonebook memory storage. The SIM card is the only storage in the

A2D


+CPBS= OK +CME ERROR :< err>

+CPBS? +CPBS:[,] +CME ERROR :CPBS=? +CPBS:( list of supported s)

Defined values:

SM SIM abbrev dialing phonebook

FD SIM fixed dialing phonebook

ONSIM own number phonebook

integer type value indicating the number of used location in selected memoryinteger type value indicating the total number of location in selected memory

Remarks: None

Source: GSM 07.07/8.11Implementation: complete

2.22 AT+CPBR

Command is used to read a specify entry or a range of entries from the phonebook

memory storage


+CPBR= +CPBR +CME ERROR

:[, ] ,,,

+CPBR:,,,

+CPBR=? +CPBR:(list of supported +CME

ERROR :s),,

Defined values:

,, integer type values in the range of location number of phonebook memory

: string type phone number of format.

: type of address octet in integer format.String type field of maximum length ; character

set as specified By command select TE character set+CSCS

: integer type value indicating the maximum length of field.

: integer type value indicating the maximum length of

field.



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Remarks: None



2.23 AT+CPBW

Command is used to while a phonebook entry to a special place in the phonebookmemory storage

Command Possible Responses+CPBW=[ OK +CME ERROR : [, [, [, ]]]

+CPBW=?

+CPBW (list of supporteds),

+CMEE ERROR :,(list of supporteds),

Defined values:

integer type values in the range of location number of phonebookmemory

: string type phone number of format.: type of address octet in integer format.

String type field of maximum length ; character set as

specified

By command select TE character set+CSCS: integer type value indicating the maximum length of field

.

: integer type value indicating the maximum length of field.

Remarks: None



Message handling commands

2.24 AT+CSCA

Command is used to set the service center address. Mobile originated message

transmitted through this service centre.

Command Possible Responses+CSCA=[,] OK

+CSCA? +CSCA:,+CSCA=? OK

Defined values:

GSM 04.11 RP service centre address. Value field in string format

GSM 04.11 RP service centre address type- of-address octet in

integer.



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Remarks: in PDU mode (at+cmgf=0) this command is needed only when the length

of the SMSC address coded into parameter equals zero

Source: GSM 07.05/3.3.1


2.25 AT+CMGLCommand is used to read selected message from SIM card storage.

Text command

Command Possible Responses+CMGL[= +CMGL:,,

+CMS ERROE: ,,[][,, ]

[

+CMGL:,, ,,[][,,][]]

+CMGL=? +CMGL: (list of supporteds)

Defined values: sting type (default REC UNREAD); indicates the status of

message in memory :REC UNREAD received unread message (i.e. new message)

REC READ received read message

STO UNSENT stored unsent message

STO SENT stored sent messageALL all messages

integer type ; value in the range of location number supported by the

associated memory. GSM 03.40 TP-originating-address address value field in string format

GSM 03.40 TP-destination-address address value field in string format

GSM 03.40 TP-service centre time stamp in time string format GSM 04.11 TP- destination address type of-address octet in integer

format

(when first character of is +(IRA43) default is 145 ,otherwise defaultis 129)

GSM 04.11TP-originating-address type of address octet in integer format

(default

refer ) integer type value indicating the length of the message body in

characters

GSM 03.40 TP user data in text mode response

PDU mode:


+CMGL[= +CMGL:,,,+CMS ERROE: [

+CMGL:.,, []]

+CMGL=? +CMGL: (list of supporteds)



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Defined values:

integer type (default 0) indicates the status of message in memory :0 received unread message (i.e.new msg.)

1 received read message

2 stored unsent message3sored sent message

4 all message

see text mode integer type value the length of actual TP data unit in octet (i.e.the RP

layer SMSC address octets are not counted in the length);

GSM 04.11 SC address followed by GSM 03.40 TDPU in hexadecimal

format

Remarks: None

Source: GSM 07.05/3.4.2.4.1


2.26 AT+CMGS

Command is used to send a message to the service centre.

Text mode:


+CMGS=[, CNGS:

+CMS ERROR: ]

Text is entered

+CMGS=? OK

Defined values:

GSM 03.40 TP-Destination-Address Address- value field in string format GSM 04.11 TP Destination- address type- of-address octet in integer

format.

(When first character of is + (IRA43) default is 145, otherwise default is 129) FSM 03.40 TP-Message-reference in integer format

PDU mode:


+CMGS= CMGS:+CMS ERROR:

PDU is given ctrl-Z\ESC>

+CMGS=? OK

Defined values:

Integer type value the length of the actual TP data unit in octets (i.e. the

RP layer SMSC address octets are not counted in the length); GSM 04.11 SC address followed by GSM 03.40 TPDU in hexadecimal format

See text mode

Remarks: When the length octet of the SMSC address equals zero, the SMSC

address set with COMMAND Service Centre Address + CSCA is used.



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Source: GSM 07.05/3.5.1,4.3


2.27 AT+CMGD

Command is used to delete a message from the SIM card storage.

Command Possible Responses+CMGD= OK +CMS ERROR:

+CMGD=? OK

Defined values:

Integer type; value in the range of location numbers supported by SIM

memory

Remarks: none

Source: GSM 07.05/3.5.4




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EXPERIMENT:-3

AIM:- Study of the AT Commands Part-1

These Commands are working

Message setting commands3.1 AT+CSMS

Command is used to select messaging services, It also shows supported services, where

stands for mobile terminated messages, for mobile originated messages and stands for broadcast type Messages.

Command Possible Responses+CSMS= CSMS:,, +CMS ERROR:+CSMS? CSMS:,,,

+CSMS=? +CSMS: (list of supported s)

Defined values:

0 GSM 03.40 and 03.41 (GSM standards for SMS, Cell

Broadcast)1127 Reserved

128Manufacturer specific,, 0 type not supported

1 type supported

Remarks: none.

Source: GSM 07.05/3.2.1


3.2 AT+CPMS

Command is used to select memory storage that will be used for reading andwriting short messages to and for writing broadcast to.


+PSMS=[, CPMS:,, +CMSERROR:

,,,

+CPMS? +CPMS:,,,

,,,

,,

+CPMS=? +CPMS: (list of supported s),(list of supported s),(list of supported

s)

Defined values:

String type; memory from which messages are read and

deleted (command List Messages +CMGL, Read Message+CMGR and Delete Message + CMGD);

Defined values:



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SM SIM message storage

BM Broadcast message storage

String type; memory to which writing and sendingoperations are made (commands Send Message from

Storage + CMSS and Write Message to Memory +CMGW)

String type; memory to which received SMS are preferredto be stored (unless forwarded directly to TE; refer

command New Message Indications +CNMI);

Refer for defined values

Integer type; total number of message locations in

Integer type; total number of message locations in

Integer type; total number of message locations in Integer type; total number of messages currently

in

< used2> Integer type; total number of messages currently

in< used3> Integer type; total number of messages currently

in

Remarks: none.

Source: GSM 07.05/3.2.2


3.3 AT+CMGF

Command is used to select format for incoming and outgoing messages. Command Possible Responses+CMGF=[] OK

+CMGF? CMGF:

+CMGF=? +CMGF: (list of supported s)

Defined values:

0 PDU mode1 Text mode

Remarks: none.

Source: GSM 07.05/3.2.3


3.4 AT+CSMP

Command is used to set additional parameters for text mode messages. Command Possible Responses+CSMP=[[,[,[,]]]] OK

+CSMP? CSMP:,,,

+CSMP=? OK

Defined values:



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: First octet of GSM 03.40 SMS-DELIVER,SMSSUBMIT in integer format

(default 17)

: GSM 03.40 TP-Validity-Period either in integerformat (default 167)or in time-string format

: GSM 03.40 TP-Protocol-Identifier in integer format (default 0)

: GSM 03.38 SMS Data Coding Scheme ( default 0) in integer formatRemarks: none.

Source: GSM 07.05/3.3.2


3.5 AT+CSDH

Command controls whether detailed header information is shown in text mode result

codes. Command Possible Responses+CSDH=[] OK

+CSDH? CSDH:

+CSDH=? +CSDH: (list of supported s)Defined values: 0 Do not show header values defined in commands +CSCA and +CSMP

(,,,,) nor,or in

+CMT, +CMGL, +CMGR result codes for SMS/PP text mode 1 Show the

values in result codes

Remarks: none.

Source: GSM 07.05/3.3.3


3.6 AT+CSCS

Command is used to set and request the implemented character set. Incoming character

are converted to the current used set Command Possible Responses+CSCS=[] OK

+CSCS? CSCS:

+CSCS=? +CSCS: (list of supported s)

Defined values:

(conversion schemes listed here are supported by the falconA2D )

GSM GSM default alphabet (GSM 03.38)

PCCP437 PC character set code page 437

Remarks: none.



3.7 AT+CNMI



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Command select the procedure how receiving of new message from the network is

indicated to TE is active (e.g. DTR signal is on), if TE is inactive (e.g. DTR signal is off)

message receiving should be done as specified in GSM 03.38 control theprocessing of unsolicited result codes specified within this commands set the result

code indicating routing for SMS DELIVER for CBMs and for the SMS

STATUS REPORTs. defines the handling method for buffered result codes when 1,2,or 3 is enabled if ME does not supported requested item (although TA does )

final result code returned .look at service failure result code for a list of

values. Test command gives the setting supported by the TA as compound values.NOTE: command select message service +CSMS should be used to detect ME supported

of mobile terminal SMS and CBM.


+CNMI=??,?, +CMS error:?,?,????

+CNMI? CNMI:,,,,

+CNMI=? +CNMI: (list of supported s, (list of supported

s,) (list of supported s), (list of supported s), (list of

supported s)

Defined values:

Only =2 is supported

Any other value for (0,1,or 3)is accepted (return code will be ok) but the

processing of unsolicited result code will be the same than for =2. 0 buffer unsolicited result code in the TA if TA result code buffer is

full indication can be buffered in some other place or the oldest

indications may be discarded and replace with the new received

indication

1 discarded indication and reject new received message unsolicitedresult code when TATE link is reserved (e.g.in online data mode).

Otherwise forward them directly to the TE.2 buffer unsolicited result codes in the TA when TA TE link is

reserved (e.g. in online data mode) land flush them to the after

reservation otherwise forward them directly to the TE.3 forward unsolicited result codes directly to the TE TA-TE link

specified in band technique used embed result codes and data when

TA is in on-line data mode.(NOTE: The rules for storing received SMS depend on message class preferred memory

storage (+CPMS) setting and this value)

No SMS DELIVER indication are routed to the TE1 indication of SMS DELIVER is routed to the TE using unsolicited result code:

+CMTI :,

2 SMS DELIVERs (except class 2 messages ) are routed directlyto the TE unsolicited

result code:? PDU mode enabled:

+CMTI :?< alpha>?



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? text mode enabled (about parameter in italic ,refer command show text mode

parameter +CSDH):

+CMTI :,??,[ ,,,,,,,?

Class 2 message result in indication as defined in =1].

3 class 3 SMS deliver are routed directly to TE using unsolicited result codes definedin =2.message of other classes result in indication as defined in

=1.

receiving procedure for different message classes(GSM 03.38 SM data coding scheme)

0 Class 0: as in GSM 03.38 but use as preferred

message if message is tried to be stored

Class 1: as in GSM 03.38 but use as preferredmemory

Class 2: as in GSM 03.38

Class 3: as class1

1 as =0 but send indication if message storedsuccessfully

2 Class 0: as in GSM 03.38, but always route message to TEdo not try to store it in memory

Class 1: route message tote

Class 2: as in GSM 03.38, but also send indication if

message stored successful message stored successfully.Class 3: route message to TE

3 Class 0, 1, 2: as =1

Class 3: route message to TE: ( the rules for storing received CBMs depend on its

message class, the setting of select CBM T type (+CSCB)

and this value)0 No CBM indications are route to the TE

1 indication of new CBM is route to the TE using unsolicited

result code: +CBMI: , 2 New CBM are routed directly to the TE using unsolicited

result code

PDU mode enabled:

+CBM: Text mode enabled:

+CBM:,,,,

3 class 3 CBMs are routed directly to TE using unsolicited

result codes defined in =2. Message of other classesresult in indication as defined in =1

receiving procedure for different messages classes

(GSM 03.38 CBM Data coding scheme)

0 store message to BM (or manufacturer specific memory )



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1 As =0 but send indication if message stored

successfully

2 Route message to TE3 Class 0, 1, 2: as =1

Class 3: route message to TE

0 No SMS STATUS-REPORTs are routed to the TE1 SMS-STATUS-REPORTs are routed to the TE using

unsolicited result code

PDU mode enabled:+CDS:

Text mode enabled:

+CDS: ,,?,?,?,,

0 TA buffer of unsolicited result codes defined within

this command Is flushed to the when TE 1..3 is

entered (ok response shall be given before flushing thecodes)

1 TA buffer of unsolicited result codes defined withinthis command Is cleared when 1..3 is entered

Remarks: none.

Source: GSM 07.05/3.3.3


3.8 AT+CSCB

Command is used to set parameter of how broadcast message are to be received. Command Possible Responses+CSCB=[[, OK

[]]]+CSCB? CSCB:,,

+CSCB=? +CSCB: (list of supported s)

Defined values:

: 0 Message types specified in andare

accepted

1 Message types specified in andare not accepted

: String type; all different possible combinations of CBMmessage identifiers (refer) (default is empty string);

: String type; all different possible combinations of CBM

data coding schemes (refer) (default is empty string);e.g. 0-3,5

Remarks: none

Source: GSM 07.05/3.3.4


3.9 AT+FCLASS

This command puts the module into a particular mode of operation (data or fax).



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Command Possible Responses+AT+FCLASS= OK

+AT+FCLASS? +FCLASS: +AT+FCLASS =? +FCLASS: (list of supported s)

Defined values:

0 Data1 Fax class1

2 Fax class 2

Remarks: none.

Source:


3.10 AT+FTM

This command sets the fax transmit speed.


+AT+FTM= OK

+AT+FTM=? (list of supported s)Defined values: 24 2400 bps (modem type : V.27ter)

48 4800 bps (modem type : V.27ter)

72 7200 bps (modem type : V.29)

73 7200 bps (long) (modem type : V.17)

74 7200 bps (short) (modem type : V.17)96 9600 bps (modem type : V.29)

97 9600 bps (long) (modem type : V.17)

98 9600 bps (short) (modem type : V.17)121 12000 bps (long) (modem type : V.17)

122 12000 bps (short) (modem type : V.17)

145 14400 bps (long) (modem type : V.17)146 14400 bps (short) (modem type : V.17)

Remarks: none.

Source:


3.11 AT+FRM

This command sets the fax receive speed. The speed values are the same than these of+FTM command.


+AT+FRM= OK +AT+FRM=? (list of supported s

Remarks: none

Source:


3.12 AT+FK

This command causes the module to terminate the session.



24/55


+AT+FK OK

Remarks: none

Source:


3.13 AT+GCAPCommand gives GSM capabilities information.


GCAP +GCAP: +CGSM +FCLASS

Remarks: none



3.14 AT+CLCK

Command is used to set and request the status of the modem or network facilities. Special

calls could be barred and passwords could be changed.

Command Possible Responses+CLCK=, OK +CME

ERROR:[,[,]] when [,

[+CLCK: ,

[]]

+CLSK=? +CLSK: (list of supported s) +CMEERROR:

Defined values:

SC SIM lock

AO Barr all outgoing calls

OI Barr outgoing international calls

OX Barr outgoing international calls except to home country

AI Barr all incoming calls

IR Barr incoming calls when roaming outside the home country

AB All barring services

AG All outgoing barring services

AC All incoming barring services

: 0 Unlock

1 Lock2 Query status

: 0 Not active

1 Active

: String type; shall be the same as password specified for the facility

from the ME user interface or with command Change Password

+CPWD

: Is a sum of integers each representing a class of information

(default 7 equals to all classes):

1 Voice



25/55

2 Data

3 Fax

Remarks: none



3.15 AT+CPWD

Command is used to set or change password for the facility locks of the commandAT+CLCK


+CPWD=, OK +CME ERROR:

+CPWD=? +CPWD: (list of supported +CME ERROR:

,s)

Defined values:

refer AT+CLCK

, string type;shall be the same as password for the

facility from the ME user interface or with command

change password +CPWD and is the newpassword maximum length of password can be determine

with .

integer type maximum length of the password for thefacility.

Remarks: none



3.16 AT+CFUN

Command is used to set the functionality of the modem. It switch between two powerconsumption levels.


+CFUN= [[,]] OK +CME ERROR:

+CFUN? +CFUN : +CME ERROR:

+CFUN=? +CFUN :( list of supported

s),(list of supported s ) +CME ERROR:

Defined values:

0 Minimum functionality1 Full functionality

0 do not the ME before setting it to power level

1 Reset the ME before setting it to power level



26/55

Remarks: The execution of AT+CFUN=0 is while the A2D-1

modem.(See SOFT_ON description) for the A2D OEM

module or ignition line description for the A2D-1 modem.



3.17 AT+CPAS

Command is used to request the phone activity status.


+CPAS +CPAS: +CME ERROR:

+CPAS=? +CPAS: (list of supported +CME ERROR:

s)

Defined values:

0 Ready (ME allows command from TA/TE)

1 Unavailable (ME does not allow command from TA/TE)2 Unknown (ME is not guaranteed to respond to instructions)

3 Ringing (ME is ready for commands from TA/TE, but theringer is active)

4 call in progress (ME is ready for command from TA/TE,

but a call is in progress)5 Asleep (ME is unable to process command from TA/TE

because it is in a low functionality state )

Remarks: none



3.18 AT&WCommand is used to store modem setting. Store setting will be available after reset orpower off.


&W OK

Remarks: none

Source: GSM07.07/v.25ter


3.19 AT&F

Command restores the factory configuration. Restore setting will be available after reset

or power off.Command Possible Responses

&F OK

Remarks: none

Source: GSM 07.07/V.25ter




27/55

3.20 AT+CMEE

Command is used to set the indication of GSM functionality errors.


+CMEE= [] OK

+CMEE=? +CMEE :< n>

+CMEE=? +CMEE: (list of supported s)Defined values: 0 Disable +CMEE ERROR: result code and use

ERRROR instead1 Enable +CME ERROR : result code and use

numeric values

Remarks: none



3.21 AT+CEER

Command is used to cause of a failure in the call setup or call modification.Command Possible Responses+CEER +CEER :< report>+CEER OK

Defined values:

cause as written below (information element as stated in

GSM recommendation 04.08)

Cause value Diagnostic

1 Unassigned (unallocated) number

3 No route to destination6 Channel unacceptable

8 Operator determine barring

10 Normal call clearing17 User busy

18 No user responding

19 users alerting no answer21 Call rejected

22 Number changed

26 Non selected user clearing

27 Destination out of order28 Invalid number format (incomplete number)

29 Facility rejected

30 Response to STATUS ENQUIRY31 normal, unspecified

34 No circuit/channel

38 Network out of order 41 Temporary failure

42 Switching equipment congested

43 Access information discarded

44 Requested circuit/channel not available



28/55

47 Resources unavailable unspecified

49 Quality of service unavailable

50 Requested facility not subscribe55 Incoming calls barred within the CUG

57 Bearer capability not authorized

58 Bearer capability not presently available63 Service or option not available, unspecified

65 Bearer service not implemented

68 ACM equal to or greater than ACM max69 Request facility not implemented

70 Only restricted digital information bearer capability is available

79 Service or option not implemented, unspecified

81 Invalid transaction identifier value87 User not member of CUG

88 Incomplete destination

91 Invalid transit network selection

95 Semantically incorrect message96 Invalid mandatory information

97 Message type non-existent or not implemented98 Message type not compatible with protocol state

99 Information element non-existent or not implemented

100 Conditional IE error

101 Message not compatible with protocol state102 Recovery on timer expire

111 Protocol error, unspecified

127 Interworking, unspecified

All other values in the range 0 to 31 shall be treated as cause 31.

All other values in the range 32 to 47 shall be treated as cause 47.All other values in the range 48 to 63 shall be treated as cause 63.


All other values in the range 80 to 95 shall be treated as cause 95.All other values in the range 96 to 111 shall be treated as cause 111.


240 FDN is active and number is not in FDN241 Call operating not allowed

252 Call barring on outgoing calls

253 Call barring on incoming calls254 Call impossible

255 lower layer failure

Remarks: none





29/55

EXPERIMENT: - 4

AIM: - Study the AT Commands Part-2

These Commands are working

4.1 AT+VTS

Command is used to transmit DTMF tones.


AT+VTS= OK

AT+VTS=? (list of supported s)

Defined values:

A single ASCII character in the set 0-9,#,*,A-D.

Remarks: none.

Sources: GSM 07.07/C.11

Implementation: complete

4.2 AT+ICF

This extended-format compound parameter is used to control the asynchronous character

framing between the DTE and DCE.


+ICF=[ OK

[,]]

+ICF? +ICF: [[,]]+ICF=? +ICF: list of supported s,

List of supporteds

Defined values:: 1 8 Data 2 Stop

2 8 Data 1 Parity 1 Stop

3 8 Data 1 Stop

4 7 Data 2 Stop5 7 Data 1 Parity 1 Stop

6 7 Data 1 Stop

: 0 Odd1 Even

4 None

Remarks: None

Sources: V.25ter/6.2.11Implementation: complete

4.3 AT+IFC

This extended-format compound parameter is used to control the operation of local flow

control between the DTE and DCE.

Command Possible responses

+IFC=, OK



30/55

+IFC? +IFC: ,

+IFC=? +IFC: list of supported,settings

Defined values:: 0 None

2 RTS line

0 None3 CTS line

Remarks: none

Sources: V.25ter/6.2.12


4.4 AT+CICB

Command is used to set the bearer type if no bearer is transmitted on an incoming call

Command Possible responsesAT+CICB= OK

AT+CICB? +CICB: AT+CICB=? +CICB: list of supported s

Definded values:

Simulated incoming bearer.0 Data

1 Fax

2 Voice

Remarks: If a wrong bearer is transmitted, the CICB setting has no effect.

Source: Factory default


4.5 AT+VGR

Command is used to set the attenuation of the modules loudspeaker.


AT+VGR= OK

AT+VGR? +VGR:

AT+VGR=? (list of supported s)

Defined values:

Integer, range 0...255, where 128 is nominal gain.

Remarks: none

Sources: GSM 07.07/C.4


4.6 AT+VGT

Command is used to set the amplification of the modules microphone.


AT+VGT= OK



31/55

AT+VGT? +VGT:

AT+VGT=? (list of supporteds)

Defined values:

Integer, range 0...255, where 128 is nominal gain.

Remarks: none

Source: GSM 07.07/C.5Implementation: complete

4.7 AT+VTS

Command is used to transmit DTMF tones.


AT+VTS= OK

AT+VTS=? (list of supported s)

Defined values:

A single ASCII character in the set 0-9,#,*,A-D.

Remarks: none

Source: GSM 07.07/C.11Implementation: complete

4.8 AT+SIDET

Command is used to set the availability and attention of the microphone signal in the

speaker.


AT+SIDET=, OK

AT+SIDET? +SIDET: ,

AT+SIDET=? (list of supporteds),list of supporteds)

Defined values:

0 Side tone is disabled.1 Side tone is enabled.

0 0 dB

1 -6dB2 -12dB

3 -18dB

Remarks: none



4.9 AT+ECHO

Command is used to enable and set the echo cancellation or the switch attenuation

parameter for the audio lines.


AT+ECHO=, OK

[,,,

,]

(for echo cancellation)



32/55

[,,,

,]

(for switch attenuation)AT+ECHO? +ECHO: ,,

,,,

+ECHO: ,,

,,

,

Defined values:

0 Deactivate Echo

1 Activate Echo

2 Configuration echo cancellation(automatically

stored in E2P)

3 Deactivate switch attenuation

4 Activate switch attenuation5 Configure switch attenuation

(automatically stored in E2P) This parameter specifies the number of taps of the

adaptive filter used for echo cancellation. The

allowed range is [2;255].

This parameter specifies the level of neededconvergence. A low value provides a high

convergence and a high value a high stability, The

allowed range is [0;4095]. A negative value provides a high sensitivity and a

positive value a low one. The allowed range is

[0;10]. If Far-end speaker detection=0, the algorithm will

always adjust the filter. For the values, adaption

runs only if far end speaker energy is greater thanFar end speaker detection value. The allowed range

is[0;1000].

Number of samples used to compute energy for

algorithm convergence evaluation. The allowedrange is [0;63].

This parameter specifies the maximum attenuation

of the switch.0 31db

1 29db

2 27db3 25db

.

.

14 3 db



33/55

15 1 db

This parameter specifies the attenuation step between attenuation and no

attenuation.0 1db

1 2db

2 3db3 4db

This Parameter specifies the relative threshold

between max and min energy information. Theallowed range is [0;31].

This parameter specifies threshold of max energy

information. The allowed range is [0;31]

This parameter specifies the attenuation for switchwhen echo algorithm has converged. This parameter

is used by echo algorithm when echo and switched

are activated together.

0 14db1 12db

2 10db3 8db

4 6db

5 4db

6 2db7 1db

0 Echo Deactivated

1 Echo Activated for Mic1/Speaker1.2 Echo Activated for Mic2/Speaker 2.

Remarks: For the A2D-1 there is no Microphone2 and Speaker2 available.



4.10 ATSO

The S0 parameter controls the automatic answering of an incoming call.


ATS0= OK

ATS0?

Defined values:

: Automatic answer after rings. A value of 0 disables automatic answering.

Remarks: none.

Sources: GSM 07.07/V.25ter/6.3.5


4.11 AT%C

This command enables or disables data compressions negotiation.




34/55

AT%C OK

AT%C?

Defined values:

: 0 no compression

2 V.42 compression, if supported

Remarks: noneSources: factory default


4.12 AT+DS

This command enables or disables V.42 data compression.


AT+DS=,,, OK AT+DS? +DS: ,,,

AT+DS=? +DS: list of supported

s,s,s,s

Defined values: Specifies the desired direction(s) of operation of the data compression function;

from the DTE point of view, (default is 3),0 Negotiated ... no compression

1 Transmit only

2 Receive only

3 Both directions, accept any direction Specifies whether or not the DCE should continue to operate if the desired result

is not obtained, (default is 0),

0 Do not disconnect if V.42bis is not negotiated by the remoteDCF as specified in

1 Disconnect if V.42bis is not negotiated by the remote DCE

as specified in Specifies the maximum number of dictionary entries which

should be negotiated, range512-4096, (default is 4096)

Specifies the maximum string length to be negotiated, range6-250,(default is 250)

Remarks: none



4.13 AT+DR

Command determines whether or not the use of V42bis is informed in a data incoming oroutgoing call. Intermediate result code +DR: is returned from the modem during

connect negotiation of a data call.


+DR=[] OK

AT+DR? +DR:

AT+DR=? +DR: (list of s)

Defined values:



35/55

: 0 Disables reporting

1 Enables reporting

: NONE Data compression is not in use. V42B RecV.42bis isin use in both directions. V42B RD Rec. V.42bis is in use in

receiving direction only.

V42B TD Rec. V.42bis is in use in transmit direction only.Remarks: The +DR intermediate result code, if enabled, is issued before the

Final result code, before the +ILRR intermediate report, and after

the service report control +CR.



4.14 AT+CCFC

Command is used to set the call forwarding service.


+CCFC=, OK

+CME ERROR: [,] When =2:+CCFC: ,

AT+CCFC=? +CCFC: (list of supporteds)

Defined values:

: 0 Unconditional

1 Mobile busy2 No reply

3 Not reachable

4 All call forwarding5 All conditional call forwarding

: 0 Disable

1 Enable2 Query status

3 Registration

4 Erasure: Telephone number to forward to. Is a sum of integers each

representing a class of information (default 7 equals to all classes):

1 Voice

2 Data4 Fax

: 0 Not active

1 Active

Remarks: none



4.15 AT+CPBF

Command is used to find a phonebook entry using a search-string.




36/55

+CPBF= +CPBF:

+CME ERROR:

,,,+CPBF:

,,,]

+CPBF=? +CPBF: , +CME ERROR: Defined values:,: Integer type values in the range of location numbers of

phonebook memory.: String type phone number of format.

: Type of address octet in integer format.

,: String type field of maximum length

: character set as set as specified by command select TEcharacter set +cscs

: integer type value indicating the maximum length of field

.

: integer type value indicating the maximum length of field

Remarks: none



EXPERIMENT: - 5



37/55

AIM: - Study the AT Commands Part-3

5.1 AT+FRH

Command used to set the fax receives speed using the HDLC protocol.

Command possible responsesAT+FRH= OK

AT+FRH=? (3)

Remarks: can only take the value 3,which corresponding to v.21channels 300 bps

Source:


5.2 AT+FTS

This command stops the transmission for the specified period.


AT+FTS=? OK AT+FTS=? (list of supporteds)

Defined values:

silence period(units of 10ms)

Remarks: none

Source:

Implementations: complete

5.3 AT+FRS

This command causes the modem to stop listening from the network and report back tothe DTE after the specified period. It is aborted if any character is received from the

application.


AT+FRS+ OK

AT+FRS=? (list of supporteds)

Defined Values:

units of 10ms

Remarks: none

Source:


5.4 AT+FDT

This command prefixes data transmission.


AT+FDT OK

Remarks: none

Source:


5.5 AT+FDR



38/55

This command initiates data reception.


AT+FDR OK

Remarks: none

Source:


5.6 AT+FET

This command punctuates page and documents transmission after +FDT command. Itindicates that the current page is complete, and whether or not there are additional pages

to be sent.


AT+FET= OK

Defined values:

0 another page next, same document

1 another document next

2 no more pages or documents3 another partial page next

4 another page, procedure interrupts5 another document, procedure interrupts

6 all done, procedure interrupts

Remarks: The remote station should respond with: +FPTS,

Source:


5.7 AT+FPTS

This command sets post page transfer response.


AT+FPTS= OK

Defined values:

1 Page good

2 Page bad: retrain requested3 Page good: retrain requested

4 Page bad: interrupt requested

5 Page good: interrupt requested

Remarks: none

Source:

Implementations: complete

5.8 AT+FBOR

This command sets the bit order for negotiation and fax page transfer. The order is related

to the bit order or radio link.


AT+FBOR= OK

AT+FBOR=? (list of supporteds)

Defined values:



39/55

0 Same bit order for negotiation and page transfer

1 Same bir order for negotiation, reserved bit order for page

transfer2 Reserved bit order for negotiation, same bit order for page

transfer

3 Reserved bit order for negotiation and page transfer

Remarks: none

Source:


5.9 AT+FBUF

This command request the size of the exchange buffer between the modem and the faxapplication. Only the read command is supported.


AT+FBUF?

Remarks: noneSource:Implementation: complete

5.10 AT+FPHCTO

This command sets the period the modem waits for another page before it assumes there

are no more pages and aborts.


AT+FPHCTO= OK

AT+FPHCTO=? (list of supporteds Defined values: 0-255sec)

Remarks: none

Source:


EXPERIMENT: 6



40/55

Aim: To Generate PN Sequence using MATLAB.

Fig: PN Sequence Generator

Code:-

clear all;

clc;

G=16; % Code length%.................Generation of preferred PN sequence................

sd1 =randsrc(1,5,[0 1]); % First user's seed.

PN1=[]; % Spreading code vector of user-1for j=1:G

PN1=[PN1 sd1(1)];

if sd1(1)==sd1(4)temp1=0;

else temp1=1;

endsd1(1)=sd1(2);

sd1(2)=sd1(3);

sd1(3)=sd1(4);

sd1(4)=sd1(5);sd1(5)=temp1;

end

stem(PN1);

OUTPUT:



41/55

PN1 =

0 1 0 1 0 1 1 1 0 1 1 0 0 0 1 1

CONCLUSION:

EXPERIMENT: 7



42/55

Aim: To Generate Gold code using MATLAB.

Gold code generator:

PN sequence

Generator1

Out

PN sequence

Generator2

Fig: Gold Code Generator

Code:-

This Program generates 10 Gold code sequences, each 10 bits long. These

codes are outputted as columns of matrix Co_Mat.

Clear allclc

G=10; % Code length

K=10; % Number of Codes or code sequences%.................Generation of first preferred PN sequence................

sd1 =randsrc(1,5,[0 1]); % First user's seed.

PN1=[]; % Spreading code vector of user-1

for j=1:GPN1=[PN1 sd1(1)];

if sd1(1)==sd1(4)

temp1=0;else temp1=1;

end

sd1(1)=sd1(2);sd1(2)=sd1(3);

sd1(3)=sd1(4);

sd1(4)=sd1(5);

sd1(5)=temp1;


PN sequence

Generator

PN sequenceGenerator

XOR 1


43/55

end

%..........................................................................

%.................Generation of Second perferred PN sequence...............

sd2 =randsrc(1,5,[0 1]);

PN2=[];for j=1:G

PN2=[PN2 sd2(1)];

if sd2(1)==sd2(2)temp1=0;

else temp1=1;

end

if sd2(4)==temp1temp2=0;

else temp2=1;

end

if sd2(5)==temp2temp3=0;

else temp3=1;end

sd2(1)=sd2(2);

sd2(2)=sd2(3);

sd2(3)=sd2(4);sd2(4)=sd2(5);

sd2(5)=temp3;

end%..........................................................................

%.........................Generation of Gold Codes.........................Co_Mat=[];

for codes=1:K

code=[];PN2(31)=PN2(1);

for k=1:G-1

PN2(k)=PN2(k+1);

endfor j=1:G

code=[code xor(PN1(j),PN2(j))];

endCo_Mat=[Co_Mat code'];

end

for row=1:Gfor col=1:K

if Co_Mat(row,col)==0

Co_Mat(row,col)=-1;

end



44/55

end

end

stem(Co_Mat);%..........................................................................

%....................Chechking corelation performance......................A=[]; AA=0;B=[];

for j=1:K

for i=1:Kfor k=1:G

AA=AA+Co_Mat(k,j)*Co_Mat(k,i);

end

A=[A AA];AA=0;

end

B=[B A'];

A=[];end

OUTPUT:

Co_Mat =

1 -1 1 -1 -1 1 -1 -1 -1 -1

1 -1 1 1 -1 1 1 1 1 1

-1 1 1 -1 1 1 1 1 1 1

-1 -1 1 -1 -1 -1 -1 -1 -1 -1-1 1 -1 -1 -1 -1 -1 -1 -1 -1

1 -1 -1 -1 -1 -1 -1 -1 -1 -11 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

Simulation Result:



45/55

CONCLUSION:

EXPERIMENT: 8



46/55

Aim: To Generate Walsh code using MATLAB

Code:-

function [op_code] = walshcode(a)

a=input('enter a =');len_walsh = 2 .^ a; %length of walsh code , and number of walsh codes

walsh_code = 1;

i = 2;while (i


47/55

1 1 1 1 1 1 1 1

1 -1 1 -1 1 -1 1 -11 1 -1 -1 1 1 -1 -1

1 -1 -1 1 1 -1 -1 1

1 1 1 1 -1 -1 -1 -11 -1 1 -1 -1 1 -1 1

1 1 -1 -1 -1 -1 1 1

1 -1 -1 1 -1 1 1 -1

Simulation Result:

CONCLUSION:

EXPERIMENT: 9



48/55

Aim: To Study about RF Satellite link.

RF Satellite Link:

This practical uses blocks from the Communications Block set's RF Impairments

Library (red blocks) to simulate the following impairments:

Free space path loss

Receiver thermal noise

Memoryless nonlinearity

Phase noise

In-phase and quadrature imbalances

Phase/frequency offsetsBy modeling the gains and losses on the link, this model implements link budget

calculations that determine whether a downlink can be closed with a given bit error rate

(BER). The gain and loss blocks, including the Free Space Path Loss block and theReceiver Thermal Noise block, determine the data rate that can be supported on the link

in an additive white Gaussian noise channel.

Structure:

This practical highlights both the satellite link model and its signal scopes. The

model consists of a Satellite Downlink Transmitter, Downlink Path, and Ground StationDownlink Receiver.

The blocks that correspond to each of these sections are

Satellite Downlink Transmitter

Random Integer Generator Creates a random data stream.

Rectangular QAM Modulator Baseband Maps the data stream to 16-

QAM constellation.

Raised Cosine Transmit Filter Upsamples and shapes the modulatedsignal using the square root raised cosine pulse shape.

Memoryless Nonlinearity (High Power Amplifier) Model of a traveling

wave tube amplifier (TWTA) using the Saleh model.

Gain (Tx. Dish Antenna Gain) Gain of the transmitter parabolic dishantenna on the satellite.

Downlink Path

Free Space Path Loss (Downlink Path) Attenuates the signal by the freespace path loss.

Phase/Frequency Offset (Doppler and Phase Error) Rotates the signal to

model phase and Doppler error on the link.

Ground Station Downlink Receiver

Receiver Thermal Noise (Satellite Receiver System Temp) Adds white

Gaussian noise that represents the effective system temperature of thereceiver.



49/55

Gain (Rx. Dish Antenna Gain) Gain of the receiver parabolic dish

antenna at the ground station.

Phase Noise Introduces random phase perturbations that result from 1/for phase flicker noise.

I/Q Imbalance Introduces DC offset, amplitude imbalance, or phase

imbalance to the signal. DC Removal (DC Offset Comp) Estimates and removes the DC offset

from the signal. Compensates for the DC offset in the I/Q Imbalance

block.

Magnitude AGC I and Q AGC (Select AGC) Automatic gain control

Compensates the gain of both in-phase and quadrature components of the

signal, either jointly or independently.

Phase/Frequency Offset (Doppler and Phase Compensation) Rotates the

signal to represent correction of phase and Doppler error on the link. This

block is a static block that simply corrects using the same values as the

Phase/Frequency Offset block.

Raised Cosine Receive Filter Applies a matched filter to the modulatedsignal using the square root raised cosine pulse shape.

Rectangular QAM Demodulator Baseband Demaps the data stream fromthe 16-QAM constellation space.

Exploring:

Double-click the block labeled RF Link: Settings to view the parameter settings for this

practical. All these parameters are tunable. This practical is updated when you click OKor Apply. The parameters are

Satellite altitude (km) Distance between the satellite and the groundstation. Changing this parameter updates the Free Space Path Loss block. Thedefault setting is 35600.

Frequency (MHz) Carrier frequency of the link. Changing this parameterupdates the Free Space Path Loss block. The default setting is 8000.

Transmit and receive antenna diameters (m) The first element in the

vector represents the transmit antenna diameter and is used to calculate the

gain in the Tx Dish Antenna Gain block. The second element represents thereceive antenna diameter and is used to calculate the gain in the Rx Dish

Antenna Gain block.

Noise temperature (K) Allows you to select from three effective receiver

system noise temperatures. The selected noise temperature changes the NoiseTemperature of the Receiver Thermal Noise block. The default setting is 0 K.

The choices are

0 (no noise) Use this setting to view the other RF impairments withoutthe perturbing effects of noise.

20 (very low noise level) Use this setting to view how easily a low levelof noise can, when combined with other RF impairments, degrade the

performance of the link.



50/55

290 (typical noise level) Use this setting to view how a typical quiet

satellite receiver operates.

HPA backoff level Allows you to select from three backoff levels. Thisparameter is used to determine how close the satellite high power amplifier is

driven to saturation. The selected backoff is used to set the input and output gain

of the Memoryless Nonlinearity block. The default setting is 30 dB (negligiblenonlinearity). The choices are

30 dB (negligible nonlinearity) Sets the average input power to 30

decibels below the input power that causes amplifier saturation (that is, thepoint at which the gain curve becomes flat). This causes negligible AM-to-

AM and AM-to-PM conversion. AM-to-AM conversion is an indication of

how the amplitude nonlinearity varies with the signal magnitude. AM-to-PM conversion is a measure of how the phase nonlinearity varies with

signal magnitude.

7 dB (moderate nonlinearity) Sets the average input power to 7 decibels

below the input power that causes amplifier saturation. This causes

moderate AM-to-AM and AM-to-PM conversion. 1 dB (severe nonlinearity) Sets the average input power to 1 decibel

below the input power that causes amplifier saturation. This causes severe

AM-to-AM and AM-to-PM conversion.

Phase correction Allows you to select from three phase offset values to correct

for the average AM-to-PM conversion in the High Power Amplifier. The selectionupdates the Phase/Frequency Offset (Doppler and Phase Compensation) block.

The default setting is none. The choices are

None No correction. Use to view uncorrected AM-to-PM conversion.

Correct for moderate HPA AM-to-PM Corrects for average AM-to-PM

distortion when the HPA backoff is set to 7 dB.

Correct for severe HPA AM-to-PM Corrects for average AM-to-PMdistortion when the HPA backoff is set to 1 dB.

Doppler error Allows you to select from three values of Doppler on the link

and the corresponding correction, if any. The selection updates the

Phase/Frequency Offset (Doppler and Phase Error) and Phase/Frequency Offset(Doppler and Phase Compensation) blocks. The default setting is None. The

choices are

None No Doppler on the link and no correction.

Doppler (0.7 Hz - uncorrected) Adds 0.7 Hz Doppler with no correction

at the receiver.

Doppler (3 Hz - corrected) Adds 3 Hz Doppler with the correspondingcorrection at the receiver, -3 Hz.

Phase noise Allows you to select from three values of phase noise at the

receiver. The selection updates the Phase Noise block. The default setting isNegligible (-100 dBc/Hz @ 100 Hz). The choices are

Negligible (-100 dBc/Hz @ 100 Hz) Almost no phase noise.



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Low (-55 dBc/Hz @ 100 Hz) Enough phase noise to be visible in both

the spectral and I/Q domains, and cause additional errors when combinedwith thermal noise or other RF impairments.

High (-48 dBc/Hz @ 100 Hz) Enough phase noise to cause errors

without the addition of thermal noise or other RF impairments.

I/Q imbalance Allows you to select from five types of in-phase and quadratureimbalances at the receiver. The selection updates the I/Q Imbalance block. The

default setting is none. The choices are

None No imbalances.

Amplitude imbalance (3 dB) Applies a 1.5 dB gain to the in-phase signal

and a -1.5 dB gain to the quadrature signal.

Phase imbalance (20 deg) Rotates the in-phase signal by 10 degrees andthe quadrature signal by -10 degrees.

In-phase DC offset (2e-6) Adds a DC offset of 2e-6 to the in-phase

signal amplitude. This offset changes the received signal scatter plot, butdoes not cause errors on the link unless combined with thermal noise or

other RF impairments. Quadrature DC offset (1e-5) Adds a DC offset of 1e-5 to the quadrature

signal amplitude. This offset causes errors on the link even when notcombined with thermal noise or another RF impairment. This offset also

causes a DC spike in the received signal spectrum.

DC offset compensation Allows you to enable or disable the DC Offset block.

The selection updates the DC Removal block. The default setting is disabled.

AGC type Allows you to select the automatic gain control for the link. The

selection updates the Select AGC block, which is labeled Magnitude AGC or Iand Q AGC, depending on whether you select Magnitude only or Independent I

and Q, respectively. The default setting is Magnitude only.

Magnitude only Compensates the gain of both in-phase and quadraturecomponents of the signal by estimating only the magnitude of the signal.

Independent I and Q Compensates the gain of the in-phase signal using

an estimate of the in-phase signal magnitude and the quadraturecomponent using an estimate of the quadrature signal magnitude.

Results and Displays:

When you run this practical, the following displays are active:

Bit error rate (BER) display In the lower right corner of the model is a display

of the BER of the model. The BER computation is reset every 5000 symbols toallow you to view the impact of the changes in the model without having to restart

the model.



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Power Spectrum Double-clicking this Open Scopes block enables you to viewthe spectrum of the modulated/filtered signal (blue) and the received signal before

demodulation (red).

If both spectra are identical, then the display shows one green spectrum. Comparingthese spectra allows you to view the effect of the following RF impairments:

Spectral regrowth due to HPA nonlinearities caused by the Memory lessNonlinearity block

Thermal noise caused by the Receiver Thermal Noise block

Phase flicker (that is, 1/f noise) caused by the Phase Noise block

End to End Constellation Double-clicking this Open Scopes block enables you

to view the scatter plots of the signal after QAM modulation (blue) and beforeQAM demodulation (red). Comparing these scatter plots allows you to view the

impact of all the RF impairments on the received signal and the effectiveness ofthe compensations.

Constellation Before and After HPADouble-clicking this Open Scopes block

enables you to view the constellation before and after the HPA (blue and red,

respectively). Comparing these plots allows you to view the effect that thenonlinear HPA behavior has on the signal.



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Fig: Power Spectrum

Fig: Transmit Constellation



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Fig: Received Constellation

CONCLUSION:

mc final practical

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