SRRC Filing Timelines for a Product Entering China
SRRC radio type approval in China takes 8 to 16 weeks, requiring local agent representation, strict customs sample clearing, and accredited domestic lab scans.
Occupied Bandwidth Testing
Meaning
Spectral measurement determines the total frequency range that contains ninety-nine percent of the transmitter signal power. Performing occupied bandwidth testing ensures that the signal does not spill into adjacent channels where it could block other users. This evaluation confirms that the modulation scheme remains efficient and clean when the radio operates at its maximum data throughput.
It helps regulatory agencies allocate specific frequency slots without risking overlap during busy network operation.
Energy Concentration
Test instruments analyze the signal to find the high and low frequency points between which nearly all energy is localized. During occupied bandwidth testing, the software measures the signal width relative to the central frequency index. If the bandwidth is too wide, it suggests poor filtering or excessive noise in the modulation stage.
High concentrations of energy outside the target window results in higher failure rates during market audits.
Spectral Guard
Filters inside the radio circuit work to keep the signal inside the limits observed during occupied bandwidth testing. Digital processors control how sharp the data transitions are to prevent the generation of wide spectral skirts. If a design has a wide bandwidth, it requires larger guard intervals between communication channels.
These gaps ensure that neighboring transmitters do not corrupt each other’s messages.
Regulatory Limit
Documents define the maximum allowed spectral width based on standard occupied bandwidth testing protocols for every wireless protocol. If a module fails this check, the hardware must be reprogrammed with lower-speed data settings to tighten the signal. Detailed graphs showing the power density across the spectrum are mandatory for every test report.
Verification provides a reliable figure for network capacity planning.