Summary of implementation methods for audio, video, digital external ports in Vietnam

The modulation of the RF signal carrier must be set according to the system the EUT is intended to use.

If no other regulations are specified, the level of the input signal at the relevant ports must be sufficient to provide an interference-free image and/or sound.

Refer to A.2.1 and A.2.2.

Examples of the technical characteristics of the digital broadcast signal for the ports of digital broadcast receivers are specified in Table A.4.

The conducted emissions of the mains power port and the radiated emissions from an EUT with broadcast reception function must be evaluated by scanning one channel for each reception policy, e.g., analog TV, DVB-T, DVB-C, analog radio, digital radio, etc.

See B.4.2.1 for guidance on determining the channels used for conducted measurements on the broadcast receiver controller port.

Representative signals must be determined by the manufacturer.

For ports supporting Ethernet traffic (e.g., 100Base-T, 1000Base-T), which can operate at multiple speeds, it may be limited to measurements only at the policies where the EUT operates at its maximum speed.

When evaluating an EUT transmitting 10Base-T Ethernet traffic, the following applies:

To conduct reliable emission measurements that reflect high LAN usage performance, it is necessary to create a LAN usage condition exceeding 10% and maintain that level for a minimum of 250 ms. The content of the test traffic includes periodic messages and pseudo-random messages to simulate actual data transmission types. (Examples of pseudo-random messages: compressed or encrypted files. Examples of periodic messages: uncompressed graphic files, memory dumps, screen updates, disk images). If the LAN maintains transmissions during idle cycles, measurements must also be taken during idle cycles.