Chuck the Cassettes
In today’s Las Vegas, security video storage has come a long way, baby.
Located between the Bellagio and Monte Carlo Resorts on the Strip, the new CityCenter is big, even by Las Vegas standards, including the development’s centerpiece, the 61-story, 4,004-room ARIA Resort & Casino. And to help ensure the safety and security of the site, Brick, N.J.-based North American Video (NAV) designed, built and implemented a state-of-the art, enterprise-wide video surveillance system. The custom hybrid solution at CityCenter is built around a Honeywell video management system and features multiple matrix systems spread across seven different head-end locations. There are more than 3,700 video surveillance cameras, all being recorded.
Networking, virtualization, compression technologies, video forensics, high definition and the need to hold video for longer periods of time are all spearheading growth in the physical security network storage market. Basically, the shift to IP-based security video is helping the shift to a more IP-centric network-based storage.
There are some common dimensions to storage, says Jeff Denworth of DataDirect Networks (DDN) of Chatsworth, Calif. “There is the raw cost of the storage system. There is efficiency; ‘How well am I using the media I bought?’ There is power efficiency. And, of course, there are data management abilities.”
Many organizations are now requiring that security video images are recorded and archived continuously from all cameras for 90 days or more, says Oliver Vellacott of IndigoVision, Edison, N.J. He points out that storage for a large IP-based system can dominate the overall cost of the system, both upfront costs and lifecycle costs, as hard drives will often need to be replaced over the life of the project. With potentially large amounts of data being stored, the technology behind the compression employed and the architecture of the storage solution are critical to ensure these extended recording times can be accommodated. Similarly, the security of the stored data is important so that individual disk and equipment failures do not result in data loss.
Surveillance storage solutions can have many challenges, thanks to myriad DVR and NVR features, but they have benefits that can range from common specifications to helpful elements such as intelligent PTZ control with preset positions and e-mail or SMS message notification upon motion detection or an alert from an event, according to Mark Wilson of Infinova, Monmouth Junction, N.J. “Today, even organizations using analog cameras tend to have digital and network video recorders for storage and retrieval of surveillance video.”
On the DVR side, upgrades make storage sense.
For example, Cupertino, Calif.-based Intransa has DVR upgrades. Start with as little as 2TB (terabytes) of recording capacity, and grow modularly and affordably as needed to support one to hundreds of DVRs.
In a networked world, there are other options. For example:
A storage area network (SAN) is a storage device such as disk arrays accessible to servers so the devices appear as locally attached to the operating system. A SAN typically has its own network of storage devices that are generally not accessible through the regular network by regular devices. The cost and complexity of SANs dropped in the late 2000s, allowing wider adoption across both enterprise and small- to medium-sized business environments.
File-based solutions include network attached storage (NAS). As of this year, NAS devices are gaining popularity. Potential benefits of network attached storage, compared to file servers, include faster data access, easier administration, and simple configuration, often arranged into logical, redundant storage containers or RAID arrays.
Then there is cloud storage, where security video is stored on multiple virtual servers, generally hosted by third parties, rather than being hosted on dedicated servers. Hosting companies operate large data centers; and people who require their data to be hosted buy or lease storage capacity from them and use it for their storage needs. The data center operators, in the background, virtualize the resources according to the requirements of the customer and expose them as storage pools, which the customers can use themselves. Physically, the resource may span across multiple servers. Cloud storage services may be accessed through a Web service application programming interface or through a Web-based user interface.
Wilson adds that, at the camera edge, and catching on, security managers are also deploying SD or secure digital storage cards. “This is especially important in applications where loss of connection to the rest of the system could lead to lost images,” Wilson says.
For some applications, storage in the camera makes sense. Bandwidth may be getting cheaper on LANs, but the problem with video across networks is getting worse, contends Doug Marman of VideoIQ, Bedford, Mass. More network cameras are being added, with a growing demand for higher resolution and faster frame rates, and the increasing need to access the video across wide-area networks, the Internet and wireless networks. “However, when you store video right in the camera, no bandwidth is needed for recording. Another benefit impacting bandwidth: When video is recorded in the camera, you don’t need to stream the video; you can send it as a clip. This makes a big difference. To stream video, you need the full bandwidth required to play that video in real time. When you send a clip, however, you can transmit the video at much lower data rates, it simply takes a little longer for the file to get through, like sending an e-mail attachment from a cell phone.”
David Coleman with Avrio RMS, the Easton, Md., integrator with a specialty in public safety, knows that the government space has a big appetite for video and its storage. Among the elements of storage he contends with: the number of days of storage, where the storage is located, how it is protected and the ease of extraction.
Combining a Server and Storage Functionality
One example centers on a Sprint, Texas, Pivot3 storage platform for the Hillsborough County Sheriff’s Office (HCSO) in Tampa, Fla. According to Pivot3’s Lee Caswell, the HCSO chose CloudBanks to both store captured video images and host the video management system software. The scale-out nature of the solution ensures that the performance and capacity of the system can handle the demands of incoming video streams and offer investment protection over time as the deployment grows.
The storage reduces cost by consolidating server and shared storage functionality in a common appliance, adds Caswell. “The amount of storage capacity required by video is a major budget item in a surveillance installation since cameras can generate one TB of data in one day,” Caswell says.
“There are times when SDs in the camera make sense. NVRs and server-based storage offer value. They are reliable and easily gotten to. Cloud-based storage offers features and the cost will come down,” says Coleman.
Elements that affect how much storage is required are video resolution, frame rate, number of cameras and the quality of the compression technology deployed.
When it comes to storage, security video data is different than other IT storage. The amount of data coming from the cameras is huge and continuous. The workload is constant, i.e. the rate of writing data to the disk is constantly high, not in bursts as with typical IT applications.
There is also security of the video. With so much valuable data being recorded, it’s important to consider security and reliability, which can include RAID disk arrays. A Redundant Array of Independent Drive (RAID) divides and/or replicates data among multiple hard drives. There are different RAID levels, giving different levels of protection. In a RAID 5 configuration, for example, the data goes across three separate disks. If any disk fails no data is lost and the computer can continue without interruption.
Of course, for analog and hybrid installations, there continues to be digital video recorders. A DVR digitally compresses analog video feeds and stores them on a hard drive. The DVR, located near the analog feeds, is in centralized architectures. In contrast, an NVR stores digital images directly from the IP-network and can be located anywhere on the network. Scalability is a challenge when it comes to DVRs. As the size of a system increases and the number of recording days increases, there is no other option but to keep adding DVRs.
Another storage element is compression.
While there are a number of compression standards, with their own advantages and disadvantages, H.264 is the latest and follows on MPEG-2 and MPEG-4 but offers improvements in video quality and compression. According to Tom Cashman, general manager of the video and transmission group at UTC Fire & Security/Interlogix, Bradenton, Fla., IP cameras offer high-quality images and advanced H.264 that will consume 15-20 percent less bandwidth than MPEG4 Advanced Simple Profile. At the recent ASIS exhibition in Dallas, his company also introduced what it calls a GE TruVision NVR to exclusively support IP video streams for live viewing and storage, and management software for centralized control.
Compression and HD
Wilson says, “H.264 is a temporal CODEC; it not only compresses data within a frame (like MJPG), it also compresses data between frames. H.264 works by transmitting a series of reference frames (R-Frames). Only data about the changes in a scene are transmitted between each R-Frame. In addition, H.264 can predict the path of moving objects, reducing the amount of data to be transmitted between R-Frames even more. Using this technique, H.264 can compress a video stream more efficiently, generating significantly less bandwidth.”
He adds, “Be careful, however, if you are using server-based video analytics for forensic analysis. Video analytics packages often only analyze the R-Frames. If the incident you are looking for occurred between the R-Frames, the package may not be able to find it.”
Another challenge: Some megapixel cameras don’t use H.264.
MJPEG does not yield the bandwidth and storage savings of H.264 because its compression algorithm is less complex. But MJPEG does not require as powerful PCs or processors as H.264. “For this reason, manufacturers still use MJPEG in high resolution megapixel cameras such as 3MP and 5MP,” says Wilson. So, although H.264 offers meaningful bandwidth and storage advantages, this has to be offset against the increased cost for more powerful PCs for video management. When using megapixel cameras, especially when viewing multiple cameras simultaneously, integrators will need to over-configure the servers in the control room to cope with the more intensive processing requirements.
The need to record security video images for 90 days or more will have a large impact on the storage requirement of the project and cost, adds Vellacott. With larger systems, the inflexibility and costs involved with an analog/DVR solution means IP video is the only way forward. It is therefore paramount that a system integrator chooses an IP solution that can deploy the very best compression technology and flexible and distributed NVR architectures, in order to minimize the additional costs due to the storage overhead.
As they did with VCRs, at some point, some security professionals will leave DVRs and NVRs behind for clustered storage, contends Wilson. Larger systems especially will start using them to communicate with servers over their IP network. Modular, they allow storage to be added over time, as needs arise.
It's a Virtual World with Virtual Servers
Virtualization is a proven software technology that is rapidly transforming the IT landscape.
Today’s powerful computer hardware was originally designed to run only a single operating system and a single application. Virtualization changes that model, making it possible to run multiple operating systems and multiple applications on the same computer at the same time. Virtualization transforms hardware into software. Software such as VMware transforms or “virtualizes” the hardware resources, the CPU, RAM, hard disk and network controller, to create a fully functional virtual machine that can run its own operating system and applications just like a “real” computer.
Hosted and Remote Video Storage
There are a growing number of hosted and remote video storage solutions aimed at system integrators and their clients. The design can let the end user determine the number of cameras from which to pull video, how long the video will be stored, how much video will be stored, as well as image size and number of frames per second. Depending on the hosted service, storage can be leveraged for a single camera up to an enterprise’s entire camera inventory. It can also provide extra capacity when adding cameras to a network, or when planning for specialized cameras.
Such an approach features browser-based, live viewing, enabling reviewing of real-time images. Video playback and video analytics offer options for using video to support investigations and deliver specific business intelligence as well as ongoing, real-time camera status. This capability helps ensure the continuity of the video network, confirming that cameras are working and delivering quality images.