Chapter 9: Calculator — Underground Parking Surveillance Design Guide

1

Network Bandwidth Calculator — Link & Transmission

Number of Cameras (N)

cams

Main Stream Bitrate per Camera (B_main)

Mbps

Sub Stream Bitrate per Camera (B_sub)

Mbps

Recording Mode Factor (F_rec) — 1.0=continuous, 0.5=event

×

Protocol Overhead Factor (F_oh) — default 1.15

×

Live View Concurrency Factor (F_live) — 0.1 = 10% cameras

×

Recording Throughput (T_rec)

552.0

Mbps

Live View Throughput (T_live)

4.6

Mbps

Total Expected Throughput (T_total)

556.6

Mbps

Recommended Uplink Capacity

1G

with ≥30% headroom

Recording

552 Mbps

Live View

4.6 Mbps

Total vs Uplink

55%

Formula: T_rec = N × B_main × F_rec × F_oh | T_live = N × B_sub × F_live × F_oh | T_total = T_rec + T_live | Uplink utilization should not exceed 70% at peak.

2

Storage Capacity Calculator — Scale & Capacity

Number of Cameras (N)

cams

Average Recording Bitrate per Camera (B_avg)

Mbps

Retention Period (D)

days

Recording Hours per Day (H)

h/day

RAID Efficiency (E_raid) — RAID6≈0.80, RAID10≈0.50

×

Safety Margin (F_safe) — default 1.20

×

Raw Video per Day

3.38

TB / day

Required Usable Capacity

121.7

TB usable

Required Raw Disk Capacity

152.1

TB raw disks

Suggested Disk Configuration

10× 18TB

RAID6 configuration

Raw Video Data

101 TB

+ FS Overhead

+10%

+ Safety Margin

+20%

Raw (RAID overhead)

152 TB

Formula: Raw/day = N × (B_avg/8) × 3600 × H / (1024²) TB | C_usable = Raw/day × D × F_fs × F_safe | C_raw = C_usable / E_raid

3

PoE Power Budget Calculator — Power Distribution & Energy

Cameras on This Switch (N_sw)

cams

Average Camera PoE Draw (P_avg)

W

Peak Camera PoE Draw (P_peak) — includes IR, heater, startup

W

PoE Standard

Switch Total PoE Budget (P_budget)

W

Safety Headroom Factor (F_head)

×

Average PoE Load

240

W average

Peak PoE Load (with headroom)

450

W peak × F_head

Budget Check (Peak × F_head vs Budget)

450W vs 370W

CHECKING

Per-Port Class Check (P_peak vs Max Port W)

15W vs 30W

CHECKING

UPS Sizing Contribution (This Switch)

308

W (switch base + avg load × 1.1)

Avg Load vs Budget

65%

Peak×Headroom vs Budget

122%

Formula: L_avg = N_sw × P_avg | L_peak = N_sw × P_peak | Check: L_peak × F_head ≤ P_budget | UPS = (switch_base + L_avg) × 1.1 | Target: <80% sustained utilization.

4

Camera Coverage & Pixel Density Calculator

Camera Sensor Resolution

Lens Focal Length (mm)

mm

Sensor Size (1/x inch)

Camera Mounting Height

m

Target Zone (Plate Width for LPR)

m

Minimum Required Pixels on Plate

Horizontal Field of View

53.1°

degrees

Coverage Width at Ground Level

2.73

meters wide

Pixels per Meter at Ground

703

px/m

Pixels on License Plate

365

px on plate width PASS

Max Distance for Required Pixels

6.2

meters from camera

Plate Pixels vs Minimum

365px / 120px min

Coverage vs Lane Width

2.73m / 4.0m lane

Formula: HFoV = 2 × arctan(sensor_width / (2 × focal_length)) | Coverage = 2 × height × tan(HFoV/2) | PPM = H_pixels / coverage_width | Plate_px = PPM × plate_width

5

UPS Runtime & Battery Sizing Calculator

Total IT Load (Core + Storage + Switches)

W

UPS Efficiency (%)

%

Battery Voltage (V)

Battery Capacity per String (Ah)

Ah

Number of Battery Strings in Parallel

strings

Battery Usable Depth of Discharge (DoD %)

%

Total Battery Energy

3.12

kWh (usable)

Actual Load on Battery (incl. UPS losses)

1304

W drawn from battery

Estimated Runtime

144

minutes

Meets 30-min Requirement?

YES

PASS

Recommended UPS VA Rating

1.74

kVA (at 0.9 PF, +20% margin)

Runtime vs 30-min req

144 min

Battery Energy Used

80% DoD

Formula: Energy_usable = V × Ah × Strings × DoD% / 1000 kWh | Actual_load = IT_load / (efficiency/100) | Runtime = (Energy_usable × 60) / (Actual_load/1000) minutes | Minimum 30 min for core; 15 min for edge.