Analog CCTV Systems: Advantages and Disadvantages

This article explores the pros and cons of analog CCTV systems, contrasting them with IP CCTV systems. Both types of systems allow viewing on smartphones, digital hard drive recording, and can produce images up to 4K 1080p HD.

What is Analog CCTV?

In an analog CCTV system, analog cameras connect to a Digital Video Recorder (DVR) via coaxial cable (RG59). The video signals are digitized and stored on a hard disk drive within the DVR.

Figure-1: Analog CCTV system block diagram

The block diagram above illustrates a typical analog CCTV setup. Many of these components are manufactured by Hikvision (Hangzhou Hikvision Digital Technology Co., Ltd.), a Chinese manufacturer.

The DVR is the central component, with other system modules interfaced to it. Hard disk drives (1 TB or 2 TB), often from brands like Seagate, are installed inside the DVR to store the recorded footage. Complete systems with all necessary components are readily available from various vendors, allowing users to select configurations based on the number of cameras needed.

Figure-2: CCTV DVR Back Panel

The DVR connects to a WiFi router via an Ethernet port (RJ45). The router, in turn, connects to the Internet Service Provider (ISP). This setup allows IP-enabled devices such as mobile phones, laptops, and tablets to access the live video streams from all connected cameras.

The video feeds from the cameras can also be viewed on a monitor connected to the DVR’s HDMI or VGA port. Cameras connect to the DVR using 75 Ohm BNC interfaces located on the back panel. Power adapters provide the necessary electricity to the cameras. Different DVR models support varying numbers of cameras, allowing users to choose a DVR that matches their needs. Microphones, speakers, and a mouse can be connected to the DVR’s Audio In, Audio Out, and USB ports, respectively.

The following table details the rear panel interfaces found on the DS-7204HTHI-K2 series digital video recorder:

Benefits of Analog CCTV

Here are some advantages of analog CCTV systems:

• Low maintenance: Analog cameras are generally simple to install and manage, leading to lower maintenance requirements.
• Low cost: Both installation and maintenance costs tend to be lower than IP-based systems.
• Ease of use: Less technical expertise is needed to install and manage these systems.
• Upgrade potential: Existing coaxial cables can often be reused, allowing for later upgrades to higher-definition analog cameras.
• Power over Coaxial: Some systems support power over coaxial cables, simplifying installation by carrying both video and power over a single cable up to about 200 meters.
• Hybrid DVRs: Many DVRs support hybrid functionality, allowing the addition of IP cameras at a later date.

Drawbacks of Analog CCTV

Here are some disadvantages of analog CCTV systems:

• Lower Resolution: Analog cameras typically offer lower resolution video compared to IP cameras.
• Limited Scalability: The number of cameras that can be added is limited by the DVR’s capacity.
• Fewer Advanced Features: Many advanced features available on IP cameras are not supported by analog CCTV models.
• Cost Ineffective for Large Scale Applications: Analog systems can become expensive for large surveillance applications due to cabling and DVR limitations.
• Difficult to Scale: Scaling an analog CCTV system is more challenging compared to IP-based systems.
• Expensive Cables: Coaxial cables used in analog CCTV systems can be more expensive than network cables used in IP systems.