IT trends impacting IP video: SDXC memory cards

With so many new technologies on the horizon, it's hard to know which ones will become proverbial game changers for the security industry. This article is the first in a series of discussions about innovations in computer networking that might reshape the way we practice our discipline.

Packing more bytes per inch

Most security applications today have two things in common: they reside on an IP backbone and they require some way to store data. This is true whether the application involves perimeter detection, access control, video surveillance or fire detection. To advance network storage, in April 2009 the Secure Digital Association released a new standard for SD memory cards called Secure Digital Extended Capacity (SDXC). The standard increases the existing capacity of SD cards from 32GB to a possible 2TB of storage in a card that can be as small as your thumbnail in the mini-SD version.

What can 2TB of storage give you? For the consumer market, the Secure Digital Association estimates that 100 high-definition movies could be stored on a single card. In the realm of video surveillance, using highly-efficient H.264 video compression a customer could record 30 images per second of high-quality, 1080p HDTV video for close to 55 days on a single card.

The 2009 standard also defined the data transfer rate starting at 104MB per second which enables the recording of 30 images per second in 1080p. That rate is expected to increase to 300MB per second in future iterations of the technology. With greater data transfer rates, network cameras can conceivably surpass recording 60 images per second in 1080p. Using SDXC implementations, manufacturers of network cameras will be able to offer a level of fault tolerance for network outages by recording locally - even with applications that require high resolution and real-time recording rates.

Moving storage from center to edge

So how could SDXC technology become a game changer in the security industry? We may see more surveillance solutions moving storage from a central server out to edge devices. Here's why:

Video systems consist of an image capturing device, a wired or wireless transmission medium, and a recording platform. Traditionally, a recording platform manages the process of recording and video retrieval, hence the commonly used term video management system or VMS. Typically centralized, these devices require hardware specifications that increase in scope and cost as a system scales. The environmental burden of scaling servers into storage farms is magnified by the increased power consumption required to cool an ever-growing number of PC platforms.

When greater-capacity SDXC memory cards become a reality, they'll offer users the option of offloading centralized storage requirement with edge-based recording. The video management system will still manage the recordings; but it will simply be a matter of developing solutions that enable the recording platform to index video clips that are stored remotely. Storing video on edge devices will give security professionals greater surveillance flexibility. For instance, law enforcement could deploy more standalone cameras throughout a city without increasing their existing centralized storage capacity.

Some may argue that this scenario is more of a redistribution of the current model than an actual game changer. But by increasing the storage capacity at the edge, manufacturers and software developers could affect the very model of how companies deploy video solutions today. Individual cameras could become complete security systems providing a cost-effective solution for situations that have limited infrastructure options. For instance, the transportation industry could deploy remote cameras powered by solar energy, decreasing the need to put a PC platform on site. Some manufacturers have deployed solutions that embed actual hard disks into network cameras. But solid-state SDXC cards will offer a greater mean-time-between-failure than hard disk, and therefore increase the camera's longevity.

Is this vision achievable? Moore's Law states that every 18 months chip performance doubles based on the number of transistors that can be placed on an integrated circuit. This gives manufactures the option of lowering the price of their existing product offering while maintaining the same performance or doubling the performance at the same cost. Today most network camera manufactures have excess capacity on their Application Specific Integrated Circuit (ASIC) or Digital Signal Processor (DSP) which can provide platforms for software developers that enable them to embed their applications directly in the camera. The biggest obstacles for deploying more complex applications such as embedding portions of a VMS directly onto the camera have been processing performance and storage. Over the next few years, with the availability of higher performance network cameras and greater capacity SDXC cards, VMS manufactures will have more options in developing decentralized solutions.

Determining rewrite limits

There are some concerns surrounding implementation of SD Memory technology particularly with regards to the finite number of times data can be "written" before the card fails. Video applications are write-intensive so manufactures need to set proper expectations for the use of SDXC in their products. Industry experts currently estimate that a 2TB memory card will support at least 5,000 rewrites before the recording becomes unreadable.

Weighing the costs

Since SDXC cards are not yet available (recent reports suggest that the first version will reach the market later this year), we cannot calculate the total cost of 2TB of storage on the edge. Today 32GB offerings are available for $139.00. The average cost per gigabyte will most likely be much higher when compared to traditional centralized storage options, but the total cost of ownership might surprise you. With centralized solutions there is also the cost of power consumption to consider. In most cases, the physical network infrastructure would be equivalent in both, rendering it a non-factor in determining total cost of ownership. On the other hand, a decentralized solution decreases overall bandwidth consumption, giving it an advantage in installations with limited bandwidth options such as alarm verification of a remote pipeline.

A new perspective on video at the edge

Like so many innovations before it, SDXC was born out of the demand generated by the consumer electronics market. Similar to our consumer counterparts, security professionals want better-quality video and greater storage and retrieval capacity for the vast quantities of video we capture. Plus, we want to do more with less. Sized at less than one-inch square and with capacity options up to 2TB, SDXC cards will offer many markets an interesting alternative to managing and storing large amounts of data such as security video.

About the author: James Marcella has been a technologist in the security and IT industries for more than 17 years. He is currently the director of technical services for Axis Communications.

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