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PC-based systems generally have a higher development rate than that of embedded technology, and as a result these products often have an advantage over embedded units in their feature offering.

However, according to Ultrak, this being said, the fundamental video management criteria have been met within various embedded DVRs available today. These fundamentals are frame rates, effective compression resulting in efficient long-term storage, storage medium flexibility, remote software via network, ISDN or PSTN medium.

Furthermore, Ultrak believes that a system's design should not revolve around the technology as such but rather the technology should be appropriate for the solution. According to the company, PCs have been designed as general-purpose devices and as a result there are many processes occurring in the background that are often not relevant to the actual systems application. This along with viruses and finger trouble may result in potential 'hang ups'. "Dedicated systems or embedded technology on the other hand only run dedicated operations, cannot read common PC viruses and finger trouble will generally not cause any major harm," says Ultrak.

Mission-critical

Security systems are mission-critical and render themselves useless if they crash. As a result there has always been a large emphasis placed on the offline capability of technology-based security systems. The prime reason for this trend, says Ultrak, is that the market users feel more confident in having the mission-critical aspects of their security systems managed by dedicated 'embedded' systems. "The biggest example of this can be found in the access control arena," says the company. "Access control systems appear more mission-critical to CCTV systems to many users. The prime reason being that in the event of a failure it is well known to the user as the access point is either locked or wide open. Although the user may not be as aware of the mission-critical element of the CCTV system it does not make it less so. It is generally only when critical video footage is required that this becomes apparent."

Ultrak believes that both the PC and embedded platforms have a critical role to play in the overall system solution. However, it is logical to use both of them in their areas of strength and try reducing reliance on their weak aspects.

"The history of access control systems have proven this by relying on embedded technology to run the mission-critical 'offline' aspect of the system and the PC and network environment to take care of database management. The PC and its flexible network environment come into their own when it comes to drawing reports and managing data, etc by multiple users on multiple sites simultaneously. Should the network, however, 'crash' or be shut down for any reason the critical data storage and mission-critical processes continue.

"The question is, 'Why should CCTV systems be any different?'" asks the company. "As mentioned above, security CCTV systems are just as mission-critical as access control systems. Therefore use the strength of both platforms by designing the CCTV system with the 'offline' aspect in mind."

Video management

Ultrak goes on to state that video management is not always used in a security application and often only used for various management processes. "In these applications, the system may not be mission-critical. It also may very well require customised database management that may not be found in the embedded environment making a PC-based solution more appropriate. Embedded technology requires volumes to make the manufacture thereof economically viable. Naturally with this borne in mind the manufacturers have to apply the 80%/20% principle. Embedded DVRs will continually increase in offering and decrease in price, making them more and more attractive for security-based video management. PC-based operating systems are certainly becoming more reliable and their flexibility definitely has the edge for specialised and customised management applications.

"We at Ultrak have found that the market has been confused by the variety and nature of DVRs available. All too often clients are not sure what priority to place on the various aspects of the DVRs they are assessing. The focus should primarily reside in the benefits of the system as opposed to the features."

According to the company, the list below should be the order of priority when selecting a CCTV solution primarily used for security purposes:

* Operating system - embedded (RTOS) or PC-based - critical to the reliability of the system.

* Frame rate - irrespective of picture quality, the picture cannot be viewed if it is not there.

* Picture quality - often resolution is confused with useable picture quality. A higher resolution in pixel rating can often produce a poorer picture quality than a lower pixel rating that is compressed more effectively.

* Compression method - the efficiency of storage is critical to network bandwidth and storage limitations affecting the overall system cost.

* Auto archiving - critical, as second to the operating system, the next weakest link is the hard drive. As in various raid set-ups it is a good idea for the system to allow for the duplication of recordings to two hard drives.

* Networkability - the system should be networkable. The system's flexibility is not decided by the choice of operating system but rather its network limitations.

* Archive ability - efficient compression and increased hard drive size limits the need for mass archiving. However, valuable incidents may need to be stored in a less volatile medium such as a CD. The networkability of most good systems available today automatically offers this flexibility.

"Naturally," says Ultrak, "one may add to this list of priorities for specific applications. However, when it comes to good reliable video management for security purposes the above should be the deciding factors. Do not allow the icon on the left or right, colour of the screen or box, to confuse your decision."

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