High-capacity storage as a technology enabler

Industry analysts have predicted that transitioning security surveillance systems from analog to digital is the most important issue impacting the security video market. High-capacity storage is seen as one of the key technology enablers to replace legacy tape-based video surveillance systems with digital systems.

Innovations in hard disk drive technologies provide the required surveillance system functionality and image quality improvements to enhance its usage flexibility and expansion. The promise of higher revenues is spurring market growth - video surveillance market revenues are forecasted to grow from $15.5 billion in 2006, to $46 billion by 2013 according to a recent study by ABI Research.
Multiple factors and technology innovations are driving the analog-to-digital evolution. Just as consumer tape-based VCRs had their limitations, so do analog-based video capture for security systems. Limits to the image quality, length of recording time, ability to simultaneously record and quick accessibility to video are all contributing factors to the demise of tape-based storage.

Advancements in digital video technologies are contributing to the accessibility, acceptance and affordability of new AV/surveillance solutions. Digital technologies have made significant improvements, including how content is accessed and archived, the ease of managing content and image quality and archival longevity. Today's H.264 video compression capabilities, fast networking connectivity, megapixel cameras and high-capacity HDDs provide a strong basis for transition to digital-based systems.

While these innovations are helping to grow the industry, they are also creating very large video files. An 8-megapixel camera can produce one terabyte of data in just three days. Even with strides in video compression, more cameras will result in an increase in video data. This is why high-capacity storage becomes an industry-enabling design element necessary to sustain a digital solution.
Storage capacity is the platform that facilitates the move from antiquated tape to digital systems. Due to constant innovation, HDDs have consistently delivered increased storage capacity while keeping prices affordable. AV/surveillance and security applications can take advantage of these huge technology achievements that have made hundreds of terabytes of storage available. High-capacity HDDs provide the performance necessary to access and retrieve stored video quickly, alleviating possible system performance restrictions.

Capacity is by no means the only enabling HDD innovation. Other elements include higher reliability, low power consumption, cool and quiet operation, universal system compatibility, the ability to simultaneously record multiple audio and/or high-definition video streams and long product life.
A 1-terabyte hard drive has a typical power consumption rating greater than 13.5 watts. Reducing the average power used by five watts can quickly produce significant cost savings for large data-intensive applications.
Power-conserving technologies are also important. New technologies that balance the rotating disk's spin speed, transfer rate and caching algorithms offer power savings.

Unnecessary power consumption has also been reduced by technologies that automatically unload recording heads during idle times to reduce aerodynamic drag, disengage read/write channel electronics, calculate optimum seek speeds or use active power management to automatically invoke an idle mode. Many of the same technologies that reduce power consumption also contribute to thermal management and quiet operation. And cool system operation equates to higher system reliability.

Any storage solution must be tested to ensure universal system compatibility with a broad range of AV/security products including set top boxes, DVRs and other mainstream surveillance systems. It also needs to be optimized for smooth, continuous digital video playback. Hard drives are available that can now handle as many as 12 simultaneous high-definition streams and 16 standard-definition streams and are based on the industry-standard ATA specification for universal compatibility. A storage system that provides simultaneous multi-tasking capabilities also gives companies the ability to use standard streaming management and error recovery options.

Storage reliability is paramount to maintaining long product life of surveillance systems. Today's HDDs have been specifically designed and tested for long product deployments in high-temperature, always-on streaming digital audio/video environments. Drives that have been specifically designed for these intensive applications typically feature a high Mean Time Between Failure (MTBF) of 1 million hours, which is higher than desktop PC hard drives. Advanced HDD technologies that help ensure longevity such as Preemptive Wear Leveling (PWL) from Western Digital have also been developed.

Ed Strong is marketing director of AV storage at Western Digital.