I. Data Bandwidth of Surveillance Cameras

1. Frame RateIt refers to the rate at which bitmap images are continuously displayed on a monitor, measured in frames per second.
2. Image ResolutionResolution defines the level of detail in a bitmap image. Generally speaking, higher resolution means more pixels, clearer images and better printing quality, yet it also increases storage occupancy.
3. Data Rate (Bitrate)Also known as bitrate, it indicates the number of high-low level transitions at a communication port within one second. More data transmitted per unit time carries richer information. As the core parameter for image quality control in video encoding, its unit is kbps.
4. Compression RateIt reflects the compression effect, calculated as the ratio of file size after compression to the original size. For example, compressing a 100 MB file into 90 MB gives a compression rate of 90%. A lower compression rate is preferred, yet deeper compression leads to longer decompression time. Common standards include H.264 and H.265.

Correlation between Parameters

For video with fixed resolution, higher frame rate delivers smoother motion and requires larger bitrate. With identical frame rate, higher resolution produces clearer images and demands larger bitrate. When frame rate and resolution remain unchanged, higher compression rate reduces bitrate.

Note: If budget permits, select cameras with advanced technology. When adopting H.265 cameras, ensure the NVR or cloud storage also supports H.265.

II. Calculation of Surveillance Storage Capacity

Relationship between byte and bit

1. Bit is commonly used as the transmission unit at the physical and data link layers for binary transmission. Residential broadband is also rated in bits.
2. Byte is generally used at the application layer to indicate file size visible to end users. 1 byte = 8 bits

Formula for daily recording file size: Bitrate × 3600 × 24 ÷ 8 ÷ 1024 = MB/day Example: Daily storage for 1080P video with H.265 compression 2 Mbps × 3600 s × 24 h ÷ 8 ÷ 1024 = 21 GB

III. Calculation Method for Camera Power Consumption

Formula: kWh = Wattage × 1 hour ÷ 1000 Example: A 2 MP Hikvision camera with maximum power consumption of 5 W Annual power consumption = 365 × 24 × 5 ÷ 1000 = 43.8 kWh If electricity tariff is 0.6 RMB/kWh: 43.8 × 0.6 = 21.9 RMB (Approximately 22 RMB per camera per year)