Manuel d'utilisation / d'entretien du produit 8922 P du fabricant Agilent Technologies
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HP/Agilent 8922 GSM HSCSD T est System Option #K09 Supplementary User’ s Guide Systems Covered HP/Agilent 8922 P Multi-Band T est System Manufacturing P art Number: 08922-90218 © Copyright F ebruar.
ii W arranty This Agilent T echnologies instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment.
iii Limitation of Remedies and Liability THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES . AGILENT TECHNOLOGIES SHALL NOT BE LIABLE FOR ANY DIRECT , INDIRECT , SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES , WHETHER BASED ON CONTRACT , T ORT , OR ANY O THER LEGAL THEORY .
iv traceable to the United States National Bureau of Standards and T echnology , to the extent allowed by the Bureau’s calibration facility , and to the calibration facilities of other International Standards Organization members.
v "restricted computer software" as defined in F AR 52.227-19 (June 1987) or any equivalent agency regulation or contract clause. Use , duplication or disclosure of Softw are is subject to Agilent T echnologies’ standard commercial license terms and non-DOD Departments and Agencies of the U .
vi Sound Emission Manufacturer’ s Declaration This statement is provided to comply with the requirements of the German Sound Emission Directive, from 18 J anuary 1991. This product has a sound pressure emission (at the operator position) < 70 dB(A).
vii intended use of the instrument. Agilent T echnologies assumes no liability for the customer’s failure to comply with these requirements . W ARNING This is a Safety Class I instrument (provided with a protective earthing ground, incorporated in the power cord).
viii Safety Symbols The following symbols on the instrument and in the manual indicate precautions which must be taken to maintain safe operation of the instrument Safety Symbols The Instruction Documentation Symbol. The product is marked with this symbol when it is necessary for the user to refer to the instructions in the supplied documentation.
ix The CE mark sho ws that the product complies with all rele vant European Le gal Directiv es. ISM 1-A This is a symbol of an Industrial, Scientific, and Medical Group 1 Class A product. The CSA mark is a registered trademark of the Canadian Standards Association, and indicates compliance to the standards defined by them.
x About this Guide Overview This User’ s Guide is a supplement to the manuals currently supplied with the HP/Agilent 8922 GSM T est Sets. The information contained in this User’ s Guide is only relevant to the additional features of the HP/ Agilent 8922 GSM HSCSD T est System.
Contents xi 1. Understanding the HP/Agilent 8922 GSM HSCSD T est System Getting an overview of the HP/Agilent 8922 GSM HSCSD T est System . 2 F eatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xii Contents HSCSD screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1. Master downlink amplitude . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. Slave offset . . . . . . . . . . . .
Contents xiii HSCSd:MAST er:DOWNlink:AMPLitude . . . . . . . . . . . . . . . . . . . . . . . 50 HSCSd:MAST er:TCH:TLEV el . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 HSCSd:MAST er:UPLink:AMPLitude . . . . . . . . . . . . . . . .
xiv Contents A. Upgrading the HOP Controller ROM and Firmware Upgrading the Hop Controller ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Upgrading the firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 1 Understanding the HP/Agilent 8922 GSM HSCSD T est System This chapter provides an overview of the HP/Agilent 8922 GSM HSCSD T est System..
2 Chapter 1 Understanding the HP/Agilent 8922 GSM HSCSD T est System Getting an overvie w of the HP/Agilent 8922 GSM HSCSD T est System Getting an overview of the HP/Agilent 8922 GSM HSCSD T est Syste.
Chapter 1 3 Understanding the HP/Agilent 8922 GSM HSCSD T est System Getting an overview of the HP/Agilent 8922 GSM HSCSD T est System The HP/Agilent 8922 GSM HSCSD T est System is used either as a st.
4 Chapter 1 Understanding the HP/Agilent 8922 GSM HSCSD T est System Features F eatures The HP/Agilent 8922 GSM HSCSD T est System supports the following features . The full range of features available in speech mode is maintained. • Support of fully variable power level of each active timeslot on the downlink.
5 2 Setting up the HP/Agilent 8922 GSM HSCSD T est System This chapter describes how to connect and set up the HP/Agilent 8922 GSM HSCSD T est System..
6 Chapter 2 Setting up the HP/Agilent 8922 GSM HSCSD T est System Before y ou start Before you start W ARNING The HP/Agilent 8922 is a Safety Class 1 product (provided with a protective earth terminal). A safety earth ground must be provided from the mains power source to the product input wiring terminals, power cord, or supplied power cord set.
Chapter 2 7 Setting up the HP/Agilent 8922 GSM HSCSD T est System Checking the HP/Agilent 8922 Requirements f or HSCSD Checking the HP/Agilent 8922 Requirements for HSCSD T o run the HSCSD functionality you need two HP/Agilent 8922 P systems (one acting as a master and one acting as a slave).
8 Chapter 2 Setting up the HP/Agilent 8922 GSM HSCSD T est System Making the front panel connections Making the front panel connections Before you connect the two HP/Agilent 8922 P systems together to.
Chapter 2 9 Setting up the HP/Agilent 8922 GSM HSCSD T est System Making the rear panel connections Making the rear panel connections Before connecting the two HP/Agilent 8922 P systems to form the HP.
10 Chapter 2 Setting up the HP/Agilent 8922 GSM HSCSD T est System Making the rear panel connections Figure 2-2 Rear panel connections GPIB cable System bus cab le 10 MHz reference cable Master Slave.
Chapter 2 11 Setting up the HP/Agilent 8922 GSM HSCSD T est System Enabling the HSCSD functionality Enabling the HSCSD functionality Y ou must enable the HSCSD test functionality within the HP/Agilent 8922 using the keycard supplied as follows. Step 1.
12 Chapter 2 Setting up the HP/Agilent 8922 GSM HSCSD T est System Enabling the HSCSD functionality Figure 2-4 T ests screen Step 4. Set Location to CARD . Step 5. Select the Procedure field and select ENABLE as the procedure. Step 6. Select the Run T est field or press the key on the front panel of the HP/Agilent 8922 to run the program.
Chapter 2 13 Setting up the HP/Agilent 8922 GSM HSCSD T est System Enabling the HSCSD functionality Figure 2-5 Config screen T o disable HSCSD functionality T o disable the HSCSD functionality , repe.
14 Chapter 2 Setting up the HP/Agilent 8922 GSM HSCSD T est System Calibrating the overall system Calibrating the overall system There is an RF loss through the system from the slave unit's reported output level to that observed by the mobile due to cable loss and a nominal 7 dB loss through the system.
15 3 Manual operation This chapter describes the basic procedures required to manually operate the HP/Agilent 8922 GSM HSCSD T est System. F or more details on operating procedures, refer to the HP/Agilent 8922M⁄S User’s Guide .
16 Chapter 3 Manual operation Configuring the system Configuring the system T o configure the HP/Agilent 8922 GSM HSCSD T est System for manual operation, proceed as follows. NO TE Y ou must configure the slave unit first as a frame reset is sent from the master unit to the slave unit as soon as the master unit is activated.
Chapter 3 17 Manual operation Configuring the system The slave unit’ s GPIB address is now automatically set to 15 (seen in the IO Config screen) which is the default Slave Address setting on the master unit. The slave unit’ s GPIB address must be the same as the Slave Address setting on the master unit and this helps to ensure this.
18 Chapter 3 Manual operation Establishing a call Establishing a call Y ou establish a call in the same way as for a speech call. Step 1. Ensure that the master timeslot is the timeslot currently being measured on the master unit. T o do this, navigate to the HSCSD control screen on the master unit and set the Measure field to Master .
Chapter 3 19 Manual operation Making measurements Making measurements Once a call is established, you can make measurements as before — see the HP/Agilent 8922 User’s Guide for more details.
20 Chapter 3 Manual operation Changing power le vels, timeslot and channels Changing power levels, timeslot and channels Y ou can change downlink and uplink power , TCH timeslot, and TCH ARFCN simply be typing in a new value on the HSCSD control screen.
Chapter 3 21 Manual operation Ending a call Ending a call Ending a call is the same procedure as that used for a standard HP/ Agilent 8922 T est System, however the master unit must be measuring the master timeslot. Refer to the HP/Agilent 8922M⁄S User’ s Guide for more information.
22 Chapter 3 Manual operation Ending a call.
23 4 Screens This chapter describes the screens that are part of the HP/Agilent 8922 GSM HSCSD T est System. F or more details on all other screens, refer to the HP/Agilent 8922M⁄S User’ s Guide . These screens are only available for firmware revision C .
24 Chapter 4 Screens Config screen Config screen Figure 4-1 Config screen 1. Instrument type HSCSD Master and HSCSD Slave indicate that the HP/Agilent 8922 is part of a multi-box solution.
Chapter 4 25 Screens Config screen • set the slave GPIB address to match the address of the slave unit • make sure that the addresses of the slave and master units are different • make sure tha.
26 Chapter 4 Screens Config screen 2. Slave address The Slave address field appears only if you have selected HSCSD Master as the instrument type and is the address used by the master unit to send GPIB commands to the slave unit. This is only used when the instrument is being operated manually .
Chapter 4 27 Screens HSCSD screen HSCSD screen Figure 4-2 HSCSD Control screen 1. Master downlink amplitude The Master downlink amplitude field shows the downlink amplitude of the master TCH. The amplitude of the slave TCH is calculated by 1 2 3 4 5 6 9, 12 10, 13 12 14 7 8 15 16 17 T ype floating point Units dBm only Limits (GSM900) -127.
28 Chapter 4 Screens HSCSD screen adding an offset (see page 28) to this value . NO TE The default is reset when you select the instrument type (see page 24). 2. Slave offset The Slave offset field determines the downlink amplitude of the master TCH by selecting the difference in amplitude between the master and slave amplitudes .
Chapter 4 29 Screens HSCSD screen The Master Channel field shows the ARFCN of the TCH. There is only one ARFCN , as HSCSD systems place all timeslots on the same ARFCN . On a slave unit, setting this field changes the ARFCN of the downlink TCH and analyzer appropriately .
30 Chapter 4 Screens HSCSD screen 4. Master timeslot The Master timeslot field indicates which timeslot is used for the master TCH. As the slave TCH is alw ays in the timeslot immediately after the master , changing this field sets the slave timeslot to the value “master timeslot plus one”.
Chapter 4 31 Screens HSCSD screen 6. Call Type The Call Type field determines which type of HSCSD call the HP/ Agilent 8922 establishes the next time a call is initiated. If you select 2x1 , the HP/Agilent 8922 tries to establish a call with 2 downlinks and 1 uplink when a call is next initiated.
32 Chapter 4 Screens HSCSD screen 7. Data rate The Data rate field determines the data rate associated with the HSCSD 2x2 call. Selecting '9.6' sets up a call at 9.6 kbit/s per timeslot (19.2 kbit/s) and selecting '14.4' sets up a call at 14.
Chapter 4 33 Screens HSCSD screen 9. Master Tx level On a master unit, the Master Tx level field requests a new transmit level for the uplink master TCH.
34 Chapter 4 Screens HSCSD screen 10. Master input level The Master Input level field sets the expected power of the master uplink TCH. Y ou can set the level indirectly by changing the master Tx level (see page 33) or you can change it directly .
Chapter 4 35 Screens HSCSD screen 11. Master mode The Master mode field either makes or breaks the link between the Master Tx level (see page 33) and the Master input level (see page 34). NO TE Note that in standard mode, setting either of these other values change the Master mode field.
36 Chapter 4 Screens HSCSD screen On both units , if the instrument is operating in standard mode, setting this field changes the slave control field (see page 37) to MS Tx Lev , then calculates and sets the slave expected input level (see page 36).
Chapter 4 37 Screens HSCSD screen control type is MS Tx Lev , then the instrument returns an error ( Can’t change setting while MS TX Lev mode is selected. ) and does not make the setting . NO TE The default is reset when you select the instrument type (see page 24).
38 Chapter 4 Screens HSCSD screen 15. Mobile reports The Mobile Reports are the same uplink SACCH reports as appear on the Cell Status screen. The reports are taken from whichever uplink timeslot is currently being analysed. Y ou make this choice using the Measurement timeslot field (see page 32).
Chapter 4 39 Screens Fast BER Screen F ast BER Screen One extra field, labelled Loopback , appears in the F ast Bit Error screen, when the HP/Agilent 8922 is in 2x1 mode. Figure 4-3 F ast BER screen The Loopback field is a toggle field and allows the choice of either master or slave .
40 Chapter 4 Screens Fast BER Screen Loopback The Loopback field selects which downlink slot is looped back on the master uplink. T ype toggle Choices “Master”, “Slav e” Default “Master”.
41 5 Remote operation This chapter explains how to operate the HP/Agilent 8922 GSM HSCSD T est System over the GPIB. The new GPIB commands for the HP/Agilent 8922 GSM HSCSD T est System are detailed. F or the syntax format of all other GPIB commands, see the Agilent 8922M⁄S Programming Reference Guide .
42 Chapter 5 Remote operation Introduction Introduction The general principle of operation is that the settings on the slave unit are relative to the settings on the master unit which allows the manual and remote interfaces to operate in the same wa y .
Chapter 5 43 Remote operation Configure Subsystem GPIB Commands Configure Subsystem GPIB Commands Figure 5-1 Configure Instrument Type comand syntax CONFigure:INST rument[:TYPE] Description Sets what role the HP/Agilent 8922 plays in the multi-slot test system.
44 Chapter 5 Remote operation Display Subsystem GPIB Commands Display Subsystem GPIB Commands Figure 5-2 Display Screen command syntax DISPlay:SCReen HSCSD Description This command selects the HSCSD control screen (or an error screen if the system is not upgraded to run HSCSD).
Chapter 5 45 Remote operation HSCSD Subsystem GPIB Commands HSCSD Subsystem GPIB Commands.
46 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands Figure 5-3 HSCSD command syntax (master unit) HSCSd TCH DOWNlink MEASure STATus TSLot ARFCn ARFCn? AMPLitude TLEVel? AMPLitude? real TSLot? .
Chapter 5 47 Remote operation HSCSD Subsystem GPIB Commands Figure 5-4 HSCSD command syntax (slave unit) SLAVe TCH STATus OFFSet real UPlink AMPLitude AMPLitude? real CONTrol? CONTrol string Sp TLEVel.
48 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSd:MAST er:TCH:ARFCn Description Setting this during a call forces a channel assignment to the given channel. Note that existing channel assignment commands sent to a master or single unit have the same effect.
Chapter 5 49 Remote operation HSCSD Subsystem GPIB Commands HSCSd:MAST er:ST A Tus:TCH:TSLot Description Setting this during a call changes the master timeslot. Note that existing timeslot commands sent to a master or single unit have the same effect.
50 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSd:MAST er:DOWNlink:AMPLitude Description This sets the downlink amplitude of the master TCH. In all cases, this sets the TCH level. T o change the amplitude of the GSM BCH in a dual band system, use the existing command DUALband:ATTenuation:GBCh .
Chapter 5 51 Remote operation HSCSD Subsystem GPIB Commands HSCSd:MAST er:TCH:TLEV el Description During a call, this sets the Tx level of the master TCH. When the system is idle (that is , not on a call), this sets the Tx level to be used when the next call is established.
52 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSd:MAST er:UPLink:AMPLitude Description This sets the expected input level of the master TCH.
Chapter 5 53 Remote operation HSCSD Subsystem GPIB Commands HSCSd:MAST er:UPLink:AMPLitude:CONT rol Description This defines the relationship between the master’s Tx level, and the master’s expected uplink amplitude . MS TX LEV indicates that setting the master’s Tx level also sets the master’ s expected uplink amplitude.
54 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSD:MAST er:CALL:TYPE Description This command selects which type of call the HP/Agilent 8922 will set up the next time a call is initiated.
Chapter 5 55 Remote operation HSCSD Subsystem GPIB Commands HSCSD:MAST er:CALL:RA TE Description This command selects the data rate of the call that the HP/Agilent 8922 will set up the next time a call is initiated. Syntax HSCSD:MAST er:CALL:RATE HSCSD:MAST er:CALL:RATE? Command options T ype toggle Units none Choices 9.
56 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSd:SLA V e:ST A T us:SYNC Description This read-only field indicates whether or not the slave unit is synchronised with the master unit. The status is set to DISABLED when you set the instrument type to HSCSD SLAVE .
Chapter 5 57 Remote operation HSCSD Subsystem GPIB Commands HSCSd:SLA V e:ST A T us:TCH:TSLot? Description This query returns the absolute timeslot. F or example, if the master’s timeslot is 3, because the sla ve’s timeslot offset is fixed at +1, HSCSd:SLAVe:STATus:TCH:TSLot? would return 4.
58 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSd:SLA V e:DOWNlink:AMPLitude:OFFSet Description This sets the amplitude offset (in dBs) of the slave timeslot, using the master’s downlink amplitude as a reference . The resulting amplitude must lie within the normal downlink power range.
Chapter 5 59 Remote operation HSCSD Subsystem GPIB Commands HSCSd:SLA V e:TCH:TLEV el Description During a call, this sets the Tx level of the slave TCH. When the system is idle (that is , not on a call), this sets the Tx level to be used when the next call is connected and the slave TCH is established.
60 Chapter 5 Remote operation HSCSD Subsystem GPIB Commands HSCSd:SLA V e:UPLink:AMPLitude Description This sets the expected input level of the slave timeslot.
Chapter 5 61 Remote operation HSCSD Subsystem GPIB Commands HSCSd:SLA V e:UPLink:AMPLitude:CONTrol Description This defines the relationship between the slave Tx level, and the slave expected uplink amplitude. MS TX LEV indicates that setting the slave’s Tx level also sets the slave’ s expected uplink amplitude.
62 Chapter 5 Remote operation Remote operating procedures Remote operating procedures NO TE F or remote operation to work: • the two HP 8922 P units must be put into master and slave mode by remote .
Chapter 5 63 Remote operation Remote operating procedures Establishing a call The procedure for establishing a call is the same as for speech. Note however , that you must be measuring the master uplink in the master unit.
64 Chapter 5 Remote operation Remote operating procedures Changing channels, timeslot and power levels P erforming a channel assignment is a single instruction. Note that the slave unit must be kept in step with the master and the master must be measuring the master uplink prior to performing a channel assignment.
Chapter 5 65 Remote operation Remote operating procedures Ending a call Ending a call is performed in the same wa y as for speech. NO TE The master or single unit must be measuring the master timeslot for the call to end cleanly . OUTPUT Master;”CELL:CALL:END” Note that only the master unit is used.
66 Chapter 5 Remote operation Example code showing a dual-band hando ver from E-GSM to DCS Example code showing a dual-band handover from E-GSM to DCS Some example code is listed below which performs a dual-band handover from E-GSM to DCS on an HP/Agilent 8922 GSM HSCSD T est System.
Chapter 5 67 Remote operation Example code showing a dual-band hando ver from E-GSM to DCS 350 ! enabled, it will IMMEDIATELY return ENABLED 360 ! 370 ! Select the HSCSD screen - it's easier to s.
68 Chapter 5 Remote operation Example code showing a dual-band hando ver from E-GSM to DCS 820 ! 830 OUTPUT Master;"DualBand:TCHC:Exec" 840 OUTPUT Slave;"DualBand:TCHC:Exec" 850 WA.
69 6 Returning equipment for repair.
70 Chapter 6 Retur ning equipment f or repair Return Procedure Return Procedure If you need to return your HP/Agilent 8922 or HP/Agilent 83220 to Agilent T echnologies, first obtain the correct Service Center shipping address from your local sales office and proceed as follows.
Chapter 6 71 Retur ning equipment f or repair Return Procedure enough to accommodate the instrument. Allow at least 7 to 10 cms on all sides of the instrument for packing material. 3. Surround the instrument with 7 to 10 cms of packing material to protect it and prevent it from moving in the carton.
72 Chapter 6 Retur ning equipment f or repair Sales and Service Offices Sales and Service Offices Any adjustment, maintenance, or repair of this product must be performed by qualified personnel. Contact your customer engineer through your local Agilent T echnologies Service Center .
Chapter 6 73 Retur ning equipment f or repair Sales and Service Offices Canada: Agilent T echnologies Canada Inc. 5150 Spectrum W ay , Mississauga, Ontario L4W 5G1 (tel) 1 877 894 4414 Europe: Agilent T echnologies T est & Measurement European Marketing Or ganisation P .
74 Chapter 6 Retur ning equipment f or repair Sales and Service Offices.
75 A Upgrading the HOP Controller ROM and F irmware This chapter describes how to upgrade the HOP Controller ROM and firmware on the HP/Agilent 8922 P to allow it to run the HSCSD functionality .
76 Appendix A Upgrading the HOP Controller R OM and Fir mware Upgrading the Hop Controller R OM Upgrading the Hop Controller ROM CA UTION Perform the following procedures at a static safe workstation. The printed circuit assemblies in the instrument are very sensitive to static electricity .
Appendix A 77 Upgrading the HOP Controller R OM and Fir mware Upgrading the Hop Controller R OM Figure A-1 Removing the top cover Step 3. Remove RF covers A and B using a TX-15 screw driver (see below). Figure A-2 Removing the RF covers A and B Step 4.
78 Appendix A Upgrading the HOP Controller R OM and Fir mware Upgrading the Hop Controller R OM Figure A-3 Removing the A33 Hop Controller Board Step 6. Remove the A33 U62 HOP Controller ROM. Y ou may need to force when removing and replacing the ROM.
Appendix A 79 Upgrading the HOP Controller R OM and Fir mware Upgrading the Hop Controller R OM Step 8. Reinstall the A33 HOP Controller board. Step 9.
80 Appendix A Upgrading the HOP Controller R OM and Fir mware Upgrading the firmware Upgrading the firmware The HP/Agilent 8922 GSM HSCSD T est System host firmware is downloaded to the instrument over the GPIB interface. This is performed using an external controller with an GPIB interface and the HP BASIC programing language.
Un point important après l'achat de l'appareil (ou même avant l'achat) est de lire le manuel d'utilisation. Nous devons le faire pour quelques raisons simples:
Si vous n'avez pas encore acheté Agilent Technologies 8922 P c'est un bon moment pour vous familiariser avec les données de base sur le produit. Consulter d'abord les pages initiales du manuel d'utilisation, que vous trouverez ci-dessus. Vous devriez y trouver les données techniques les plus importants du Agilent Technologies 8922 P - de cette manière, vous pouvez vérifier si l'équipement répond à vos besoins. Explorant les pages suivantes du manuel d'utilisation Agilent Technologies 8922 P, vous apprendrez toutes les caractéristiques du produit et des informations sur son fonctionnement. Les informations sur le Agilent Technologies 8922 P va certainement vous aider à prendre une décision concernant l'achat.
Dans une situation où vous avez déjà le Agilent Technologies 8922 P, mais vous avez pas encore lu le manuel d'utilisation, vous devez le faire pour les raisons décrites ci-dessus,. Vous saurez alors si vous avez correctement utilisé les fonctions disponibles, et si vous avez commis des erreurs qui peuvent réduire la durée de vie du Agilent Technologies 8922 P.
Cependant, l'un des rôles les plus importants pour l'utilisateur joués par les manuels d'utilisateur est d'aider à résoudre les problèmes concernant le Agilent Technologies 8922 P. Presque toujours, vous y trouverez Troubleshooting, soit les pannes et les défaillances les plus fréquentes de l'apparei Agilent Technologies 8922 P ainsi que les instructions sur la façon de les résoudre. Même si vous ne parvenez pas à résoudre le problème, le manuel d‘utilisation va vous montrer le chemin d'une nouvelle procédure – le contact avec le centre de service à la clientèle ou le service le plus proche.
