Chapter 5: Selection & Interfaces

Core product overview, function specifications, quantitative requirements, and interface design

5.1 Core Product Overview

The underground parking surveillance system is composed of five camera product families, three network device categories, three platform components, and a set of supporting infrastructure products. Each product family has defined key selection criteria and typical deployment positions that determine which product type is appropriate for each zone. Selecting the wrong product family for a zone — for example, using a general dome camera instead of a dedicated LPR camera at the entrance — creates a predictable evidence quality failure that cannot be corrected through configuration alone.

Core Product Family Overview

Figure 5.1: Core Product Family Overview — Camera Types, Network Devices, Platform Components, and Support Products with Key Selection Criteria and Deployment Positions

5.2 Core Product Functions

Each core product category has a defined set of functional capabilities that must be verified during procurement and commissioning. The following product cards list the minimum required functions for each product type. Functions marked as optional represent capabilities that are recommended for most deployments but may be omitted based on site-specific requirements and budget constraints.

A. Entrance LPR Camera — Minimum 10 Required Functions
1 High WDR mode (≥120dB) for portal backlight and headlight glare
2 Fast shutter control (1/500–1/2000s) for moving vehicles
3 Plate ROI exposure — independent exposure zone for plate area
4 IR/white light synchronization with camera shutter cycle
5 Onboard plate snapshot buffering for event-triggered capture
6 ANPR/LPR engine (optional edge-based) with API event output
7 Multi-stream output: main stream (evidence) + sub stream (preview)
8 Tamper detection alarm (lens block, housing tilt)
9 Heater and anti-fog option for cold/humid environments
10 ONVIF Profile S/T compliance + vendor SDK support
B. Ramp / Aisle WDR Camera — Minimum 10 Required Functions
1 True WDR (≥120dB) for headlight reflections on ramp walls
2 Low-light noise reduction (3D DNR) for dark ramp zones
3 Motion blur optimization (shutter/gain balance at 15 km/h)
4 Corridor mode (9:16 aspect) for long narrow ramp coverage
5 Lens distortion correction for wide-angle ramp views
6 Privacy masking for areas outside facility boundary
7 H.265 smart codec with ROI encoding for bandwidth efficiency
8 Health telemetry (temperature, bitrate, uptime) via SNMP
9 Edge motion analytics for event bookmark generation
10 Vandal-resistant housing (IK10) with anti-tamper mounting
C. Panoramic Multi-Sensor Camera — Minimum 10 Required Functions
1 Multi-lens stitching with seamless panoramic output
2 Independent exposure control per sensor for mixed lighting
3 Dewarping engine for corrected perspective view
4 Zone-based analytics with independent alarm rules per sensor
5 Multi-stream output: stitched panoramic + individual sensor streams
6 ROI encoding to reduce bandwidth on low-activity zones
7 Calibration tools for stitch alignment after installation
8 Wide-scene alarm linkage (motion, intrusion, loitering)
9 Tamper detection for each sensor independently
10 ONVIF Profile S/T compliance for VMS integration
D. VMS Platform — Minimum 10 Required Functions
1 Camera management: discovery, configuration, health monitoring
2 Recording policies: continuous, schedule, event-triggered, pre/post buffer
3 Multi-camera synchronized playback with timeline alignment
4 Event and plate indexing for fast forensic search
5 Role-based access control (RBAC) with least privilege enforcement
6 Immutable audit logs with user action tracking
7 System health monitoring dashboard with alarm notifications
8 Evidence export with cryptographic hash (SHA-256) and chain of custody
9 HTTPS REST API for third-party integration (billing, access control)
10 HA failover with automatic camera rebind to standby node

5.3 Quantitative Requirements

The following table defines the minimum and recommended quantitative specifications for each critical system parameter, along with the engineering rationale and the consequence of specification mismatch. These values must be verified during procurement and confirmed during acceptance testing. Any specification below the minimum requirement constitutes a non-conformance that must be documented and resolved.

Parameter Minimum Requirement Recommended Engineering Rationale Mismatch Consequence
WDR (Entrance) ≥120 dB ≥140 dB Headlights and backlit exits create extreme contrast Plate washout; billing disputes unresolvable
FPS (Entrance) ≥25 fps 50 fps Higher FPS reduces motion blur probability Missed frames; blurred plates at higher speeds
Shutter Range To 1/2000 s To 1/5000 s Fast shutter freezes plate motion at 30 km/h Motion blur; unreadable plates
PoE Budget per Switch Ports × (avg W) +30% margin Prevents brownout during simultaneous camera startup Reboot loops; recording gaps during power events
Uplink Capacity ≥4× access sum / oversub ratio 10G per floor Prevents congestion during peak recording periods Packet loss; recording gaps; evidence unusable
Storage Write Throughput ≥1.2× total bitrate ≥1.5× RAID overhead and burst writes require headroom Dropped frames; recording gaps under load
RAID Level RAID5 minimum RAID6/10 RAID6 tolerates 2 simultaneous disk failures Data loss on second disk failure during rebuild
Time Synchronization NTP mandatory NTP + monitoring Multi-camera replay requires aligned timestamps Timeline disputes; multi-camera replay unusable
Mismatch Consequences Summary: Plate unreadable → billing dispute lost; network congestion → recording gaps → evidence invalid; no NTP → multi-camera replay unusable; weak IP rating → water ingress failures; undersized UPS → abrupt shutdown corrupts recording database; poor lens/focal choice → insufficient pixels-on-target; weak cybersecurity → unauthorized playback and evidence export.

5.4 Connection and Interface Design

The interface design covers four classes of connections between system components: video streams, event data, physical I/O, and identity/time services. Each interface class has a defined protocol, direction, and compatibility requirement. The diagram below illustrates the typical wiring and interface logic from a camera through the network to the VMS platform, and from the VMS to all integrated external systems.

Typical Wiring and Interface Logic Diagram

Figure 5.2: Typical Wiring and Interface Logic — Camera to VMS Platform with NTP, Gate, Fire Alarm, Access Control, and Billing System Interfaces

Interface Classes

Interface Class Protocol Direction Key Parameters
Video Stream RTSP / ONVIF Profile S/T Camera → VMS H.265 main stream + sub stream; multicast optional
LPR Events HTTP POST / SDK / MQTT Camera/Engine → VMS JSON payload: plate, confidence, lane, timestamp
Gate Control Dry Contact / RS-485 VMS → Gate Controller Open/close pulse, 24V DC; relay output
Billing System HTTPS REST API VMS ↔ Billing Plate + timestamp + lane ID; retry logic required
Fire Alarm Dry Contact / API Fire Panel → VMS Zone ID; triggers fire mode in VMS
Access Control SDK / OSDP / API Access ↔ VMS Door events: forced open, held open, access denied
Time Synchronization NTPv4 NTP Server → All Devices Offset <500ms mandatory; monitoring alert on drift
Management / Monitoring SNMP v3 / Syslog All Devices → Monitor SNMP traps; syslog to central server; health metrics

Compatibility and Upgrade Strategy

  • Prefer ONVIF conformance for camera discovery and basic control; use vendor SDK only for advanced LPR features that require proprietary APIs
  • Maintain a stable IP address plan with reserved pools per zone; document MAC-to-location mapping in the network management system
  • Camera replacement should not require VMS re-architecture: preserve ONVIF profiles, naming conventions, and use configuration templates for rapid deployment
  • Plan firmware upgrade windows with rollback packages; store golden configuration files for all device types in a version-controlled repository