CE Certification of Multimedia Devices with xDSL Ports

For multimedia devices equipped with xDSL ports, specific test requirements are specified in Tables 2.2 and 2.3 of the EN 55035 standard. These include tests for broadband impulse noise interference (repetitive) and broadband impulse noise interference (isolated). Before conducting these tests, it is necessary to prepare a suitable line simulator in advance and adopt the Cyclic Redundancy Check (CRC) method observed by the Equipment Under Test (EUT). For multimedia devices with xDSL ports, in addition to meeting the conventional requirements for surge (CS) and Electrical Fast Transient (EFT) in Electromagnetic Susceptibility (EMS), they must also undergo broadband impulse noise interference tests.

Test Requirements for Broadband Impulse Noise Disturbance

Setup and Test Duration for Broadband Impulse Noise Interference Tests

Broadband impulse conducted interference applies repetitive noise pulses and isolated noise pulses to the DSL port of the Equipment Under Test (EUT) respectively. Tables 2.2 and 2.3 list the level requirements, impulse durations, and impulse periods for this test.

This test procedure is carried out in accordance with the CDN method specified in iec 61000-4-6:2008, but the signal generator is replaced with a device capable of generating white noise pulses.

①　For repetitive pulse tests: Each test port shall be subjected to interference for at least 2 minutes.

②　For isolated pulse tests: At least five isolated pulses shall be applied, with an interval of at least 60 seconds between each pulse.

System Setup for xDSL Products

Line Attenuation for Different xDSL Standards

Pass Criteria for Broadband Impulse Noise Disturbance (Repetitive)

After establishing a connection, when broadband impulse (repetitive) disturbance is applied, the modem shall be able to train and minimize link interruptions for end-users. Therefore, the following procedures and performance criteria apply. The Impulse Noise Protection (INP) level supported by the EUT shall be selected for the immunity test, and the level used shall be specified in the test report. The maximum delay shall be set to 8 ms.

①　Without impulse disturbance: Within the noise margin related to the transmission rate, the modem shall not retrain. The transmission rate depends on line attenuation and line steady-state noise (the actual value is between the minimum and maximum transmission rates preset at the port). Then, the impulse disturbance shall be applied at the required test level.

②　With impulse disturbance: The modem shall not require retraining or perform Severely Errored Second (SES) operations at the bit rate set before the application of impulse noise, nor shall there be additional CRC errors due to impulse noise.

06 Standards to Be Met for Broadband Impulse Noise Interference (Repetitive)

The number of allowed CRC errors varies with different impulse durations.

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