SOCIALIST REPUBLIC OF VIETNAM

QCVN 98:2015/BTTTT

National technical regulationon ADSL2 and ADSL2+ transceiver

HANOI - 2015

TABLE OF CONTENTS

1. General regulation……………………………………………………………………...………5

1.1. Adjustment scope........................................................................................................................5

1.2. Applicable object.........................................................................................................................5

1.3. Referenced documents.................................................................................................................................................................5

1.4. Word explanation........................................................................................................................5

1.5. Abbreviated words.........................................................................................................................7

2. TECHNICAL REGULATIONS.................................................................................................9

2.1. General requirements.................................................................................................................9

2.2. Requirements to ADSL2 and ADSL2+ transceiver...........................................................9

2.3. General requirements for ADSL2 +transceiver ..............................................................................................................................................................15

3. MEASUREMENT METHOD.......................................................................................................18

3.1. Bandwidth satisfaction............................................................................................................18

3.2. Total transmission power........................................................................................................18

3.3. DC resistance.............................................................................................................................19

3.4. Impedance...................................................................................................................................19

3.5. Vertical balance.........................................................................................................................20

3.6. Insertion loss and insertion loss distortion.........................................................................20

3.7. Upward transmission speed (or downward transmission speed)..................................22

3.8. PSD mask...............................................................................................................................................................22

4. REGULATION ON MANAGEMENT...................................................................................22

5. RESPONSIBILITIES OF ORGANIZATION, INDIVIDUAL.........................................23

6. IMPLEMENTATION.................................................................................................................23

REFERENCE DIRECTORY.............................................................................................................................................................24

2.

Introduction

QCVN 98:2015/BTTTT is built on basis of TCVN 8077:2009 “Transceiver on digital subscriber 2 and 2+ asymmetrical line (ADSL) – Technical requirements”.The technical regulations and methods of measurement in accordance with the Recommendations G.992.3 (04-2009) and G.992.5 (01-2009) of ITU and ETSI TS 101 388 V1.4.1 of European Telecommunications Standards Institute (ETSI).QCVN 98:2015/BTTT is composed by Research Institute of Posts and Telecommunications, evaluated and approved by Department of Science and Technology, promulgated by Ministry of Information and Communications with Circular No36/2015/TT-BTTTT date December 23, 2015.

3.

4.

National technical regulationon ADSL2 and ADSL2+ transceiver

1. GENERAL REGULATION.

1.1. Adjustment scope

This regulation specifies the technical requirements for ADSL transceiver equipment, type ADSL2 + supporting simultaneous transmission of voice services and information loading channels on POTS on a pair of metal wires, duplexer, frequency division (FDD).1.2. Applicable object

This regulation is applied to organizations individuals in Vietnam and foreign country with production, business operation of equipment in scope of adjustment of this Regulation in territory of Vietnam.1.3. Referenced documents

QCVN 22:2010/BTTTT “National technical standards on electrical safety for telecommunication transceiver”.TCVN 7189: 2009: Information technology equipment - Characteristics of radio frequency interference - Limits and methods of measurementITU-T G992.1: 1999 Asymmetric digital subscriber line (ADSL).

ITU-T G996.1: 2001 Test procedures for digital subscriber line (DSL) transceivers.

ITU-T O.42: 1988 Equipment to measure non-linear distortion using the 4-tone intermodulation method.1.4. Word explanation

1.4.1. ADSL line

ADSL line is characterized by a metal transmission line using the same encryption algorithm. This encryption algorithm allows monitoring of the digital transmission signal and analog signal on the entire line. ADSL lines are limited by two end points, they are called the line endpoints. The ADSL line endpoints are the points in which the use of analog encryption algorithms and digital signal is monitored to ensure integrity. ADSL line is defined between α and β reference points (see Figure 1).1.4.2. Upwards

Data transmission direction from ATU-R to ATU-C (see Figure 1).

1.4.3. Downwards

Data transmission direction from ATU-C to ATU-R (see Figure 1).

1.4.4. Tip and Ring

Tip and Ring are two parts of the phone jack. Tip is the end with notch and ring is a round-shaped tube.

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QCVN 98:2015/BTTTT

1.4.5. Actual transmission speed

The total data speed on all transmission channels via the entire transmission route in a certain direction.1.4.6. Transmission status

ATU-C or ATU-R state is achieved after all initialization and trial processes are completed. In this state, the data is transmitted on the transmission channel.

ATU-C ATU-R

MPS-TC MPS-TCNTR

C U

R

C

R

-TC#

1TPS

-TC#

0

Giao

diệnứ

ngdụ

ng MPS

-TC

PM D PM D MPS-

TC - TC#1

TPS

-TC#

0

I/F I/F

I/F I/F

TPS

TPS

OAMInterfaceNTR

App

licat

ion

inte

rfac

e

Specific application no change according to application Specific application

Figure 1 – Function model of ATU

AN V-C

C

PHY

ATU

-

U-C2

DSLHPF

gLPF U-C U-R

GSTNSplitter

CSignal line

Interface cross-section

CPENT T-R T/S

ATU

-R

PH Y Family network

CPEU-R2

HPF

LPF

Splitter

R Cords providing POTS service

Figure 2 - Reference model for the case of used far divider

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QCVN 98:2015/BTTTT

AN V-C

ATU-

C

PHY

U-C2

DSLHPF

LPF U-C U-RGSTN

Bộ chiaC

Signal line

Interface cross-section

CPENT T-R T/S

AT U- R

PH Y

Mạnggia đình

CPEU-R

LPFTelephone

Modem voice bandTuỳ chọn

S Cords providing POTS service

Figure 3 - Reference model for the case of not used far divider

1.5. Abbreviated words

ADSL

ATU

ATU-C

ATU-R

ATU-x

CO

CP

CPE

DSL

FDD

GSTN

HPF

LCL

LPF

MAXNOMPSDus

MAXNOMATPus

Asymmetric digital subscriber lineAsymmetric digital subscriber line

ADSL Transceiver Unit ADSL Transceiver Unit

ATU at the central office end ATU at the central office end

ATU at the remote transceiver end ATU at the remote transceiver end

ATU-C or ATU - R ATU-C or ATU - R

Central office Central office

Customer premises Customer premises

Customer premises equipment Customer premises equipment

Digital subscriber line Digital subscriber line

Frequency division duplex Frequency division duplex

General switched telephone General switched telephone

network network

High-Pass filter High-Pass filter

Longitudinal conversion loss Longitudinal conversion loss

Low pass filter Low pass filter

Max NOMPSDus Max NOMPSDus

Maximum nominal aggregate Maximum nominal aggregate

transmit power transmit power

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QCVN 98:2015/BTTTT

MBW

MIB

NOMPSDus

NSCus

NT

NTR

OAM

PHY

PMS-TC

PMD

POTS

PSD

PSTN

RX

TC

TPS-TC

T-R

T/S

TX

U-C

U-R

V-C

ZHP

Measurement Bandwidth

Management information base

Nominal transmit PSD level ATU-RThe highest subcarriers index ATU-RNetwork termination

Network timing reference

Operations, administrationand management

Physical layer

Physical media specific - Transmission convergencePhysical media dependent

Plain Old Telephone Service

Power Spectral Density

Public Switched Telephone NetworkReceiver

Transmission Convergence (sub layer)

Transmission Protocol - Specific Transmission Convergence Layer

Interface(s) between ATU-R and switching layer (ATM or STM or Packet)Interface(s) between ATU-R and switching layer (ATM or STM or Packet)Transmitter

Loop interface – Central office endLoop interface – Remote transceiver endLogical interface between ATU-C and a digital network element such as one or more switching systemsImpedance High-Pass filter

Measure Bandwidth Management

information base

Nominal transmit PSD level ATU-R

The highest subcarriers index ATU-R

Network termination Network

timing reference

Operations, administration andManagement

Physical layerPhysical media specific - Transmission Convergence

Physical media dependent

Plain Old Telephone Service

Power Spectral Density

Public Switched Telephone Network

Receiver

Transmission Convergence (sub layer)

Transmission Protocol-Specific Transmission Convergence layer

Interface(s) between ATU-R and switching layer (ATM or STM or Packet)Interface(s) between ATU-R and switching layer (ATM or STM or Packet)Transmitter

Loop interface – Central office end

Loop interface – Remote transceiver endLogical interface between ATU-C and a digital network element such as one or more switching systems

Impedance High-Pass filter

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2. TECHNICAL REGULATIONS

2.1. General requirements

ADSL2 and ADSL2+ transceiver must:

+ Support for IPv6 WAN configuration;

+ Support for SNMP and TR069 management protocol.

2.1.1. Requirements to ADSL2 and ADSL2+ transceiver

ADSL2 transceivers must support the operation with non-overlapping spectrum ranges (ie frequency division duplexer - FDD).ADSL2 transceiver must support actual transmission speed of at least 8 Mbit real/s for downward and 800 kbit/s for upward.ADSL2 transceiver must simultaneously support ADSL according to G.992.1 and G.992.3 recommendations.2.1.2. General requirements for ADSL2 +transceiver

ADSL2 + transceivers must support the requirements for ADSL2 transceiver and meet the following requirements:- ADSL2 + transceiver must support actual transmission rate of at least 16 Mbit/s for downward and 800 kbit /s for upward.- ADSL2 + transceiver must support ADSL according to both G.992.3 and G.992.5 recommendations.2.1.3. Electrical safety requirements

Equipment must comply with the provisions in QCVN 22:2010/BTTTT: "National Technical Regulation for Electrical safety for telecommunications transceiver". 2.1.4. Requirements for Electromagnetic Compatibility

Equipment should conform to the requirements for electromagnetic compatibility specified in TCVN 7189: 2009: "Information Technology Equipment – Characteristic of radio frequency interference - Limits and methods of measurement".2.2. Requirements for ADSL transceiver (ATU-R) - type ADSL2

2.2.1. The functional characteristics of the ADSL transceiver

2.2.1.1. Upward ADSL spectrum mask of ADSL transceiver

Bandwidth is defined as the range from 25.875 to 138 kHz and is the widest used band. The limits defined in this bandwidth are also applicable to used narrower band.Figure 1 is a limited spectrum mask for the transmission signal. Low frequency blocking band is a frequency range lower than 25.875 kHz and POTS bandwidth, high frequency band is the frequency higher than 138 kHz.

9.

f band (kHz) The equation of the straight line (dBm/Hz)0 f ≤ 4 -97,5, with the largest power in the frequency band from 0 to 4 kHz is + 15

dBrn4 f ≤ 25,875 -92,5 + 21,5 × log(f/4)

25,875 f ≤ 138 -34.5.138 f ≤ 307 -34,5 - 48 × log(f/138)

307 f ≤ 1 221 -90.1221 f ≤ 1 630 -90 peak, with the largest power in the window [f, f + 1 MHz] is (-90 -

48 × log(f/1221) + 60) dBm1630 f ≤ 11 040 -90 peak, with the largest power in the window [f, f + 1 MHz] is -50

dBmNOTE 1 - All PSD measurements using impedance of 100 ; total voice band capacity measurements using impedance 600 .NOTE 2 - The PSD values and the frequency at the breakpoints are correct; slope values are approximate.NOTE 3 - Peak PSD must be measured with a resolution bandwidth of 10 kHz for frequencies higher than 25.875 kHz.NOTE 4 - The power in 1 MHz sliding port is measured with 1 MHz bandwidth, starting at the measurement frequency.NOTE 5 - Jump in the PSD mask at 4 kHz frequency to satisfy the requirements of V.90Recommendation. Originally, the PSD mask continued use of 21-dB slope/octave below 4 kHz frequency and reached bottom - 97.5 dBm/ Hz at a frequency of 3400 Hz. This may not satisfy the requirements of V.90 recommendation, therefore, the bottom value is extended to 4 kHz frequency.NOTE 6 - All PSD measurements and power must be performed in U-C interface (see Figures 2 and 3).

Figure 4 - Mask of transmission PSD of transceiver

ADSL method of measurement: in accordance with section 3.8 of this regulation.

2.2.1.2. Satisfaction and PSD in bandwidth

There are 3 PSD masks for transmission signals of ADSL transceiver, depending on the type of transmitted signal. PSD level is not greater than the maximum PSD bandwidth level in the entire bandwidth range, determined as follows:- NOMPSDus + 1 dB, for initialization signals to the channel recovery phase;

- REFPSDus + 1 dB, during the remaining process of initialization, starting from trial phase of transceiver;- MAXNOMPSDus - PCBus + 3.5 dB, in transmission status.

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Table 1 - The control parameters of the ADSL transceiver

Parameters Default values

NSCus 32.NOMPSDus - 38 dBm/HzMAXNOMPSDus - 38 dBm/HzMAXNOMATPus 12,5 dBm

Change in group delay in bandwidth not greater than 50 µs.

Permitted maximum bandwidth PSD level for the effects of non-ideal filter is 1 dB.Measuring method: in accordance with section 3.1 of this regulation.

2.2.1.3. The total transmission power

There are three different PSD masks for transmission signals of ADSL transceiver, depending on the type of signal transmitted (see 2.2.1.1). In all cases:- Total transmission power in the voice band is measured in U-R interface, and is transmitted to PSTN carrier interface not greater than + 15 dBrn (measurement method according to ITU-T Rec. G.996.1);- Total transmission power in the whole bandwidth is not greater than 0.5 dB compared with (MAXNOMATPus- PCBus) to estimate the discrepancies in the deployment, and not greater than 13.0 dBm.- Total transmission power over a frequency range from 0 to 11.040 MHz is not higher than 0.8 dB compared with (MAXNOMATPus - PCBus) to estimate excess transmission power in the bands and the discrepancies in the implementation.Measuring method: in accordance with section 3.2 of this regulation.

2.2.2. The electrical characteristics

2.2.2.1. Identification of impedance statesThe source and load impedances of ADSL transceiver must comply with the following provisions, in which ZS and ZL are the power and load impedances in active state; ZS -hi and ZL-hi, are the power and load impedance at high status greater than the ZS and ZL impedances respectively. The equipment suppliers must select the ZS -hi and ZL-hi impedances higher than ZS and ZL impedances with determined value.The requirements for the following ADSL transceiver allow the installation of multiple ADSL transceivers on the same pair of wires although only allow an ADSL transceiver to active at a time. The parameters and measurement procedures are set forth in Section 2.2.2.4.In each impedance state given in Table 2, the ADSL transceiver block must satisfy PSD mask of ADSL transceiver given in Section 2.2.1.1.

QCVN 98:2015/BTTTT

Table 2 - The impedance states of the ADSL transceiver

States of the ADSL transceiver

Power impedance

Load impedance

Not powered ZS-hi ZL-hi

Not ready ZS-hi ZL-hi

(Powered but the transceiver device does not operate)Not operate ZS-hi ZL-hi

(Powered but the transceiver device does not operate and receiver operates to transmit C-TONES signal)Operation ZS ZL

(Powered with the transceiver device operating,initializing or in the transmission status)

Measuring method: in accordance with section 3.4 of this regulation.2.2.2.2. Provisions for voltage and current of POTS

The electrical characteristics must be satisfied when the POTS loop current has value of 0 mA to 100 mA, and voltage of loop circuit is as follows:- DC voltage with a value of 0 V to -60 V.

- The ring signals not larger than 103 V rms at a certain frequency in the range from 20 to 30 Hz with a DC component with value in the range from 0 V to -60 V.

2.2.2.3. The electrical characteristics of the ADSL transceiver in operational status

2.2.2.3.1. The DC characteristics

Input DC impedance of the ADSL transceiver at U-R interface must be higher or equal to 5 MΩ.NOTE - The installation of the filters of the most common splitter is to connect the low-pass and high-pass filters in parallel at U-R port. In this diagram, the high-pass filter will block the DC component by the capacitors.

2.2.2.3.2. Characteristics of voice band - Entrance Impedance

Virtual component of the ADSL transceiver input impedance when measured in the UR interface, in the frequency range from 0 kHz to 4 kHz should have values equivalent to a capacitor with a value of 20 nF to 34 nF (approximately impedance from 1.1 k to 2.0 k at 4 kHz frequency) for ADSL transceiver integrated with splitter with high-pass filter (ie the DC blocking capacitors have value of 120 nF are integrated with ATU-R).2.2.2.3.3. Characteristics of ADSL bandwidth - vertical balance

Vertical balance at U-R interface must be higher than 50 dB in the frequency range from 30 kHz to 11 104 kHz.If HPF part of the POTS splitter is integrated in ATU, vertical balance measurement in the specified frequency range should be implemented as Figure 5. When LPF and HPF parts of POTS splitter are integrated in ATU, vertical balance measurement in specified frequency range must be performed with the POTS interfaces terminated with ZTR impedance, as shown in Figure 6.

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QCVN 98:2015/BTTTT

Figure 5 - Methods for measuring vertical balance in frequency range higher than 30 kHz (HPF is integrated in ATU)

Place machine = open circuitLift machine:

Figure 6 - Method of measuring vertical balance in the frequency range above 30 kHz (HPF and LPF are integrated in ATU)

This balance level should be measured even when with and without DC base voltage to the equipment under test that has been powered up, in the operating state and standby state. In some cases, the base voltage can be higher than or lower than a certain value, but it must be high enough to recognize when there are balancing problems related to DC base voltage. This base voltage must be connected with the inductors with good impedance coordination. The impedance of the coils must be ≥ 5000 jΩ in the specified frequency range. The 200 Ω resistors should be mounted more to ensure safety.The capacitors are coupled in diagram for measuring to block large DC current through 50 Ω resistors.The impedance of the capacitors must be ≤ | - 0,5j Ω | on specified frequency range.The inductors and capacitors in the measuring diagram should be coordinated with impedance so as not to affect the measurement results. When the ratio between the impedance of inductors and capacitors to used 50 Ω resistor is high, the coordination of impedance is lower.The coordination of the impedance of the coil is often easier to achieve when using a two-wire coil on a single core to create a pair of wires coordinating with impedance. Ensure no resonance occurring in the measurement frequency range. We can use two inductors (various sizes) connected in series to meet the requirements when the measurement is in the broadband range. It is important to ensure in the DC measurements, no saturation phenomena occurs in inductors.

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QCVN 98:2015/BTTTT

At the same time, also note that some types of capacitors have values varying with voltage; generally high quality resins are suitable.Vertical balance (LBal) is determined by the formula:

LBal 20 log e1 dB ( 1)

emIn which

e1 vertical voltage (compared to station ground or ATU ground);em voltage measured on the termination resistor.

Measuring circuit must have balance level 20 dB higher than balance level of the EUT (when balance level is lower, the measurement will have bigger errors). To ensure this, you need to replace the equipment under test using two 50 resistors and appropriate capacitors as shown in Figure 7. The circuit is balance appropriately if the balance level is 20 dB greater than required level when Tip and Ring points are connected in each measurement configuration (Tip with A and Ring with B, and Tip with B and Ring with A) with calibration impedance. Failure to achieve balance shows an imbalance in measurement circuit or calibration impedance. There should be an additional resistor in calibration circuit when the EUT is integrated with HPF and LPF as shown in Figure 6. This resistor creates a DC line; therefore, inductors are not saturated by the DC electric currents in the test conditions.

Zcalibration

Chỉ áp dụng đối với mạch 2:

Figure 7 - Calibration Circuit

2.2.2.4. The electrical characteristics of the ADSL transceiver in a high impedance state

High impedance state includes unpowered, non-operated impedance state, and non-operated impedance states as specified in Table 1.NOTE - The electrical characteristics of the ADSL transceiver in a high impedance state specified for a single ADSL transceiver also have the ability to apply for a maximum of 3 ADSL transceivers in a high resistance state and are connected in parallel and to a ADSL transceiver in operation status at a specified time.

2.2.2.4.1. The DC characteristics

Input DC resistance of the ADSL transceiver on U-R interface should be higher than or equal to 5 MΩ.Measuring method: in accordance with section 3.3 of this regulation.

2.2.2.4.2. The characteristics of the voice band

a) Insertion loss

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QCVN 98:2015/BTTTT

Insertion loss of ADSL transceiver in a high frequency impedance state is less than 33 dB at 3.4 kHz, and must be less than 1 dB at 12 kHz and 16 kHz. Insertion loss of 3 ADSL transceivers on the same line is less than 1 dB at 3.4 kHz, and less than 3 dB at 12 kHz and 16 kHz.b) Insertion loss distortion

Insertion loss distortion of ADSL transceiver in a high impedance state, when compared with insertion loss at 3.4 kHz, needs to be lower than ± 0.33 dB in the frequency range between 200 Hz and 4000 Hz. Insertion loss distortion of 3 ADSL transceivers in the frequency range from 200 Hz to 4000 Hz is less than ± 1dB.c) Intermodulation distortion

4-tone set, as specified in ITU-T O.42 recommendation, at -9 dBm level, when taken to ADSL transceiver in a high impedance state, should generate intermodulation distortion components of level 2 and level 3, at least 80 dB and 85 dB lower than the received signal level, respectively.Measuring method: in accordance with section 3.6 of the regulations.

2.2.2.4.3. The characteristics of the ADSL band

a) Insertion loss

Insertion loss of ADSL transceiver in a high impedance state, for the signal received by the ATU-C is active, less than 0.33 dB at 100 kHz (a frequency in the transmission band of ADSL transceiver is operating).Insertion loss of ADSL transceiver in a high impedance state, for the signal received by the ADSL transceiver that is operating, less than 0.33 dB at 500 kHz (a frequency in the collection band of active ADSL transceiver).

b) Insertion loss distortion

Insertion loss distortion of ADSL transceiver in a high impedance state for the signal received by ADSL transceivers is active and less than 0.33 dB in the frequency range from 25 to 1104 kHz.Measuring method: in accordance with section 3.6 of the regulations

2.2.2.4.4. Characteristics beyond ADSL band

a) Insertion loss

Insertion loss of ADSL transceiver in a high impedance state must be less than 0.33 dB at 5 MHz and at 9 MHz.b) Insertion loss distortion

Insertion loss distortion of ADSL transceiver needs to be smaller than 0,33 dB on the frequency range from 4 MHz to 10 MHz.Measuring method: in accordance with section 3.6 of this regulation.

2.3. + Requirements for ADSL transceiver equipment (ATU-R) - type ADSL2 +

ADSL2 + type devices should meet all the requirements in section 2.2 and except the requirements set forth in Sections 2.3.1 and 2.3.2.2.3.1. The functional characteristics of the ADSL transceiver

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QCVN 98:2015/BTTTT

2.3.1.1. Upward Spectrum mask play of ADSL transceiver

Bandwidth is the band from 25.875 kHz to 138 kHz and is the widest possible used band. These limits defined in this bandwidth are also applicable to a narrower used band.Figure 8 is a limited spectrum mask for the transmitted signal. Low frequency blocking band are frequencies lower than 25.875 kHz and include POTS band, high frequency band is frequencies over 138 kHz.

PSD–34.5 dBm/HzPSD peakdBm/Hz

21.5 dB/octave –72 dB/octave PSD peak –100 dBm/HzIn window 10 kHz

-97.5. PSD peakpeak –15 dB/octave+15 dBrn In window 1 MHz0-4 kHz With frequency higher than

3750 kHz

–93.2 dBm/Hz

–92.5 dBm/Hz–100 dBm/Hz -110. dBm/Hz –112 dBm/Hz

0. 4. 25,875. 138. 243. 686. 1411.1630. 5275. 12000. Frequency, kHz

Frequency (kHz) PSD level (dBm/Hz) MBW0. - 97,5 100 Hz;4. - 97,5 100 Hz;4. - 92,5 100 Hz;

10. interpolate 10 kHz;25.875. - 34,5 10 kHz;138. - 34,5 10 kHz;243. - 93,2 10 kHz;686. -100. 10 kHz;5 275 -100. 10 kHz;

12 000 -100. 10 kHz;In addition, the PSD mask shall meet the following requirements:

Frequency (kHz) PSD level (dBm/Hz) MBW1 411 -100. 1 MHz;1 630 -110. 1 MHz;5 275 -112. 1 MHz;

12 000 -112. 1 MHz;NOTE 1 - All PSD measurements use impedance of 100 ; total voice band power measurements use 600 .impedance NOTE 2 – PSD values and frequencies at the breakpoints are correct; slope values are approximations. The line points are connected with linear straight lines on the graph dB/ log (f).NOTE 3 - MBW is the measurement bandwidth. MBW value is specified for a certain breakpoint with f i frequency applicable for all frequencies satisfying fi f fj, in which fj is the frequency of breakpoints specified next.

NOTE 4 - The power in 1-MHz sliding window is measured with a 1-MHz bandwidth, starting at the measurement frequency, ie the power in the window [f, f 1 MHz] must follow the rules at frequency f.

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QCVN 98:2015/BTTTT

NOTE 5 - Jump in the PSD mask at 4 kHz frequency to satisfy the requirements of V.90Recommendation. Originally, the PSD mask continued use of 21-dB slope/octave below 4 kHz frequency and reached bottom - 97.5 dBm/ Hz at a frequency of 3400 Hz. This may not satisfy the requirements of V.90 recommendation, therefore, the bottom value is extended to 4 kHz frequency.

NOTE 6 - All PSD measurements and power must be performed in U-C interface

Figure 8 - PSD mask of ADSL transceiver

Measuring method: in accordance with section 3.8 of this regulation.2.3.1.2. Satisfaction and PSD in bandwidth

There are 3 PSD masks for transmission signals of ADSL transceiver, depending on the type of transmitted signal. PSD level is not greater than the maximum PSD bandwidth level in the entire bandwidth range, determined as follows:- NOMPSDus + 1 dB, for initialization signals to the channel recovery phase;

- REFPSDus + 1 dB, during the remaining process of initialization, starting from trial phase of transceiver;- MAXNOMPSDus - PCBus + 3.5 dB, in transmission status.

Table 3 - The control parameters of the ADSL transceiver

Parameters Default values

NSCus 32.

NOMPSDus -38 dBm/Hz

MAXNOMPSDus -38 dBm/Hz

MAXNOMATPus 12,5 dBm

Changes in bandwidth group delay are not greater than 50 µs.

Permitted maximum bandwidth PSD level for the effects of non-ideal filter is 1 dB.Measuring method: in accordance with section 3.1 of this regulation.

2.3.1.3. The total transmission power

There are three different PSD masks for transmission signals of ADSL transceiver, depending on the type of signal transmitted (see 2.2.1.1). In all cases:- Total transmission power in the voice band is measured in U-R interface, and is transmitted to PSTN carrier interface not greater than + 15 dBrn (measurement method according to ITU-T Rec. G.996.1);- Total transmission power in the whole bandwidth is not greater than 0.5 dB compared with (MAXNOMATPus- PCBus) to estimate the discrepancies in the deployment, and not greater than 13.0 dBm.- - Total transmission power over a frequency range from 0 to 11.040 MHz is not higher than 0.8 dB compared with (MAXNOMATPus - PCBus) to estimate excess transmission power in the bands and the discrepancies in the implementation.Measuring method: in accordance with section 3.2 of this regulation.

2.3.2. Electrical characteristics

According to the requirements of section 2.2.3 (excluding vertical variable attenuator parameters) applied to band range to 1104 kHz, satisfy the bandwidth to 2208 kHz.

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QCVN 98:2015/BTTTT

ADSL transceiver must have longitudinal conversion loss (LCL) of at least 50 dB in the frequency range from 30 kHz to 1104 kHzADSL transceiver must have longitudinal conversion loss (LCL) of at least 40 dB in the frequency range from 1104 kHz to 2208 kHz.

3. MEASUREMENT METHOD

3.1. Bandwidth satisfaction

InterfaceU-C/R T

SpectrumEUTanalyzer

Resistor R ATU-C/R

RGrounding point

Figure 9. Test configuration meeting the transmission frequency spectrum

Connect the device as shown in Figure 9.

Set the spectrum analyzer to collect the bandwidth signals with resolution bandwidth of 10 kHz and video bandwidth of 100 Hz. Resistor R = 100 .Signal assessment matching PSD mask

3.2. Total transmission power

Connect the device as shown in Figure 10.

Set the spectrum analyzer to collect signals in the bandwidth with the resolution bandwidth of 1 kHz and video bandwidth of 100 Hz.Record frequency value at two points corresponding to the nominal capacity decreasing by 3 dB. Bandwidth is calculated by the subtraction between the two frequency values.Connect the device as shown in Figure 10.

Use the bandwidth filter with bandwidth equal to values calculated in the step above.

Measure and record the total signal power value with termination impedance of R = 100 .

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QCVN 98:2015/BTTTT

Interface

Voltage

U-C/R T

EUTBandwidth

filterMeterResistor R ATU-C/R(rms)

RGrounding point

Ground

Figure 10 – Configuration of measuring total transmission power

3.3. DC resistance

Interface

U-C/R T

EUTDC resistorATU-C/Rmeter

RGrounding point

Ground

Figure 11 – Configuration of the DC resistance measurement

Connect the device as shown in Figure 11.

DC resistance measurement without supplying power to the equipment under test / when powering but transmitter and receiver have not operated/ when powering but transmitters has not operated and receiver is operating to transmit C-TONES signal/ when powering, receiver and transmitter are operating and initializing or in transmission state.3.4. Impedance

Connect the device as shown in Figure 12.

Measuring impedance when powering, receiver and transmitter are operating and initializing or in transmission state.

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QCVN 98:2015/BTTTT

Interface

U-C/R T

Resistance meter EUT ATU-C/R

R Grounding point

Ground

Figure 12 - Configuration of Impedance3.5 Vertical balance

See section 2.2.2.3.3.

3.6. Insertion loss and insertion loss distortion

3.6.1. Insertion loss and insertion loss distortion in voice band

Connect the device as shown in Figure 13.

Measurement of insertion loss/ insertion loss distortion in the frequency range from 0.2 to 4 kHz; at 12 and 16 kHz frequencies without supplying power to the equipment under test /when powering but transmitter and receiver have not operated/ when powering but transmitters has not operated and receiver is operating to transmit C-TONES signal

Transmission

Interface EUT

U-C/R ATU-C/Rmeter TTransmitting port HPF ATU

RLPF

Receiving port

Grounding point

Ground

(a) HPF and LPF integrated

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Transmission

Interface EUT

U-C/R ATU-C/Rmeter TTransmitting port HPF ATU

LPFR

Receiving port

Grounding point

Ground

(b) Only HPF is integrated

Figure 13 – Configuration of measuring insertion loss and insertion loss distortion in voice band

3.6.2. Insertion loss and insertion loss distortion in the ADSL frequency band and beyond ADSL band

Connect the device as shown in Figure 14.

Measurement of insertion loss/ insertion loss distortion in the frequency range from 25 to 1104 kHz; and from 4 to 10 MHz without supplying power to the equipment under test /when powering but transmitter and receiver have not operated/ when powering but transmitters has not operated and receiver is operating to transmit C-TONES signal

Transmission

Interface EUT

U-C/R ATU-C/Rmeter TTransmitting port HPF ATU

RLPF

Receiving port

Grounding point

Ground

(a) HPF and LPF are integrated

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Transmission

Interface EUT

U-C/R ATU-C/Rmeter TTransmitting port HPF ATU

R

Receiving port

Grounding point

Ground

(b) Only HPF is integrated

Figure 14 – Configuration of measuring insertion loss and insertion loss distortion in ADSL band and beyond ADSL band

3.7. Upward transmission speed (or downward transmission speed)

Interface

U-C/R TSimulation

EUTmeterATU-C/RATU-R/C

RGrounding point

Ground

Figure 15 - Upward transmission speed measuring configuration (or downward transmission speed) and PSD mask

Connect the device as shown in Figure 15.

Set simulation measuring machine in ATU-C simulation mode to measure the upward speed (or downward speed).3.8. PSD mask

Connect the device as shown in Figure 15.

Set simulation measuring machine in ATU-C simulation mode to measure PSD mask.

4. REGULATION ON MANAGEMENT

The ADSL transceivers of types ADSL2 and ADSL2 + in adjustment range specified in Section 1.1 shall comply with the technical requirements specified in this regulation.

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5. RESPONSIBILITIES OF ORGANIZATION, INDIVIDUAL

Organizations, individuals with production, business operations of ADSL transceivers of types ADSL2 and ADSL2+ must comply with regulations on duly certificates and declaration of and under the inspection of the State management authority according to current regulations.

6. IMPLEMENTATION

6.1. Department of Telecommunication and Department of Information and Communication must be responsible for instructing, developing and managing ADSL transceivers of types ADSL2 and ADSL2+ to be suitable with this Regulation.

6.2. In case the regulations stated in this Regulation are changed, supplemented or replaced, follow regulations in new documents. /.

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REFERENCE DIRECTORY

[1] ITU-T Recommendation G.992.3 (04/2009), Asymmetric digital subscriber line transceivers 2 (ADSL2).[2] ITU-T Recommendation G.992.5 (01/2009), Asymmetric digital subscriber line transceivers - Extended bandwidth ADSL2 (ADSL2).

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