Search Our Site

Our Newsletter

Our Ramblings

Choosing CCTV Cameras

cctv1Setting up a CCTV camera system is not something to be taken lightly. It is a significant expenditure and should be thought through before a single pound is spent. The most important part of any CCTV system is the camera as it provides the eyes of the operation, so to speak. The key to buying the right CCTV camera is not simply in going out and buying the biggest or most expensive model on the market.

The key is to start by identifying the needs a camera has to meet. Once those needs are known, it becomes easier to find the right camera, as opposed to spending a large amount of time trying to select a camera without really knowing how or why it will be used. Knowing what matters to a given purchaser not only speeds the decision process, but also helps to ensure they make the right CCTV camera purchase decision. Therefore, the key is knowledge, knowing what to look for in order to meet the user’s needs.

How a CCTV Camera Works

Most CCTV, or closed-circuit TV cameras used in home security work, are solid-state electronic devices that are connected to a central recorder rather than broadcasted over the air. It is, therefore, a closed circuit, broadcasting to a specific location, rather than to anyone in range. The camera itself is usually made up of the following main components: lens, sensor, and digital signal processor, or DSP. In simplest terms, the lens focuses the light that is to be imaged onto the sensor, which then passes it to the DSP which converts it into a TV signal. This signal is then transmitted to a central location either by wire or wirelessly for storage and viewing.

Factors to Consider When Purchasing a CCTV Camera

There are a number of important factors to consider when purchasing a new CCTV camera, most of which map to one or more of the basic hardware components, so understanding the components and how they affect the CCTV camera’s performance is an important part of knowing what to look for.

Choosing the Right Lens

The lens is what gathers the light for the sensor. Everything the viewer sees, or that gets recorded on the DVR comes through the lens. It determines the distance at which a car’s number plate can be read, and a face can be recognised because the lens controls focus. In many cases, a better lens is more helpful than a higher output resolution, as the output is always limited by the input, and the lens determines the input.

Buyers should also look for a zoom lens. Some CCTV cameras come with digital zoom, where others have optical zoom, handled by the lens. Whenever possible, buyers should opt for optical over digital zoom. The problem with digital zoom is that it provides no more information than was in the original image. Optical zoom can actually add new information as it changes which light reaches the sensor.

Choosing the Right Sensor

Not all digital sensors are created equal. There are two main things to look for when studying the sensor specifications of a given CCTV camera: the first is the sensor type, the second is the sensor size. Most CCTV sensors are either CMOS or CCD. CMOS is less expensive and uses less power than CCD, but it is less sensitive and does not produce as clear an image, which can be particularly problematic when using the camera for identification purposes. One result of this is that CMOS-based sensors require more signal processing to produce a clear image.

The other important factor is the sensor size. The larger the sensor, the more light it can process, and the higher quality image it can produce. Most CCTV camera sensors come in one of two sizes: 1/4 inch, which measures 3.2 mm by 2.4 mm, and 1/3 inch, which measures 4.8 mm by 3.6 mm; giving it over twice the surface area of the smaller sensor. A larger sensor not only gathers more light, but in doing so gives the DSP more data to work with, which is especially helpful with the less capable processors used in budget cameras.

Choosing the Right Output Resolution

One very common specification for CCTV cameras is the number of horizontal lines of TV resolution it can output, or its TVL. This can range anywhere up to 700TVL, with many cameras coming in between 380TVL and 540TVL. Some experts recommend 420TVL as a minimum, but this is not always the case. While a high resolution is nice to have, the output depends on the input, so if the lens and sensor cannot match the output resolution, which is determined by the DSP, then the extra resolution is wasted. What matters most is having enough resolution to clearly display any image the camera can produce. Anything beyond that is unnecessary.

CCTV Camera Types

Not all CCTV cameras are the same size and shape. Different uses require different capabilities, and so there are different kinds of cameras to meet those needs. The following table shows the three basic types of cameras and some of their common uses.

 

CCTV Camera Type

Use

Bullet Camera These small cylindrical CCTV cameras are often used in environments where discretion is important, but there is no need to permanently install the camera in a protective dome. They work well in shops and service areas when there is a need to monitor the staff
Dome Camera A CCTV dome camera is an excellent choice for surveillance as it not only protects the camera from casual vandalism, but also provides a degree of security as it is often impossible to tell where the camera is pointed
IR Day/Night Camera While obvious in appearance, these cameras have the advantage of providing 24-hour outdoor coverage regardless of lighting conditions. They provide a colour image in the daytime, shifting to black and white for infrared viewing at night

Which camera a given buyer wants to use depends on their goals and needs. Understanding those needs make choosing the right CCTV camera that much easier.

Choosing the Right CCTV Camera

When choosing the right camera for a given purchaser’s needs, there are several things the buyer should look for. The first is a lens that gives the user a clear image of the area covered by the camera from its mounting point. If the area under surveillance is not in focus, then there is no real point to monitoring it. The next feature is the sensor, whenever possible buyers should go for the 1/3 inch CCD sensor as this provides the most information for the DSP to process. The final feature of the camera itself is the output resolution. While many companies may put this feature first, its usefulness is limited by the components in front of it.

Once the hardware capabilities have been determined, the next step is to decide which type of camera best fits the user’s needs. Those covering large outdoor areas, such as homeowners wanting to cover their property, may want to consider a day/night camera. Bullet cameras work well for monitoring staff, while ceiling-mounted dome cameras are good for covering the entire premises of a shop or business.

Conclusion

There are a number of things to look for when buying CCTV cameras. Some are technical factors which apply to every situation regardless of the intended use: every camera can benefit from a better lens and high quality sensor. Other factors are more dependent on the intended use of the CCTV camera, as some types are more useful in some situations than others. A day/night camera is great for keeping an eye on visitors coming up the drive, but it may not be the best choice for monitoring staff or business premises.

Many businesses may be better served with either dome cameras covering the entire floor or small bullet cameras to monitor the staff. Regardless of the buyer’s needs, it pays to look for quality. Therefore, understand how CCTV cameras work and the importance of optical zoom as opposed to digital zoom makes it easier to recognise said quality. The most successful purchases are informed purchases, and knowing what to look for makes buying a CCTV camera much easier.

Reporting As A Business Tool

reportingThe business IT environment is changing rapidly as more enterprises move to the cloud. The resulting dependence on bought-in applications will make service assurance a key issue for both enterprises and service providers.

Enterprise managers and service providers alike need a service assurance tool that is easy to use and accepted as an industry standard.

Therefore, just as enterprises have long outsourced business functions such as fleet management, building maintenance and training, they are now increasingly happy -doubtless in many cases deeply relieved – to outsource their IT systems. As a strategy it’s entirely consistent with the general imperative to make businesses leaner, more efficient and less burdened with overhead.

So as IT comes of age, it leaves home. The situation changes from:“Our business is successful because we control our own applications running on our own servers’ to: “Our business is successful because top-quality service providers deliver all our IT.”

Once the basic need for service assurance is recognised, the next logical step is to look at the scope for standardising it. Because without a standard service assurance platform, an enterprise customer could end up with as many reporting formats as it has service providers. This is already happening, as service providers agree on the need to give customers a service monitoring facility but don’t agree – or haven’t yet agreed – on the need for all customers to use the same reporting format.

From the customer’s point of view this is a messy and increasingly unacceptable situation. They find themselves having to learn to use several different tools, all with different login procedures, all with different reporting formats, and probably none of them directly comparable with any other provider’s reports. And to cap it all, most reports are in technical language that enterprise managers may not be able to interpret without help from their own IT engineers – if they have any, with many of their services in the cloud.

An unsurprising outcome is that in practice, enterprise managers have access to service assurance tools but don’t use them as much as they should. And given that the data is largely incomprehensible anyway, there may be a strong sense that they’re not missing much. This isn’t good for either enterprises or service providers, and it doesn’t help the cause of service assurance or the cloud.
It’s a compelling argument for a single service assurance tool that everyone can use. Not just IT engineers, but also – primarily, in fact – enterprise managers who want information in a format they can use to make management decisions. They want a tool that is actually helping them to run and improve their business, and isn’t just paying lip service to a clause in an SLA about providing service assurance data.

How Useful Is Syslog

syslogThe foremost use of syslog is for systems management. Proactive syslog monitoring really pays off because it significantly reduces downtime of servers and other devices in your infrastructure. Then there is the cost savings from preventing loss of productivity that usually accompanies reactive troubleshooting.

Alerting is another good use of syslog. You have a variety of options and severity levels that you can choose in setting up syslog alerts, including emergency, critical, warning, error, and so on. Also, alerts have fine points like host details, time period, and log/message details. The following are different areas where syslog alerting is useful:

  • Network alerting: Syslog is extremely helpful in identifying critical network issues. For example, it can detect fabric channel errors on a switch fabric module. This is one of many such warnings or errors that other forms of monitoring metrics cannot detect.
  • Security alerting: Syslog messages provide detailed context of security events. Security admins can use syslog to recognize communication relationships, timing, and in some cases, an attacker’s motive and/or tools.
  • Server alerting: Syslog can alert on server startups, clean server shutdowns, abrupt server shutdowns, configuration reloads and failures, runtime configuration impact, resource impact, and so on. All these alerts can help detect if the servers are alive. Syslog also helps detect failed connections. Server alerts are always useful, especially when you oversee hundreds of servers.
  • Application alerting: You need application alerting for troubleshooting live issues. Applications create logs in different ways—some through syslog. When you run a Web application, dozens of logs are written in the log folder. To get real-time monitoring, you need a syslog monitoring solution that can observe changes in the log folder.

Monitoring high-availability (HA) servers is important and another good use of syslog. However, not all the logs from the HA server are important. You just need to monitor the logs that are troublesome. However, in case of a HA server failure, you still need all the logs from the server. The solution for this is to have a dedicated syslog server for your HA cluster.

Despite the importance of proactive monitoring, some logs can only be analyzed later. Sometimes an alert or an error sends only basic details that are located in the local memory buffer. For detailed analysis, you need to dig into the historical syslog reports using any syslog analysis tool, like LogZilla®, Kiwi Syslog®, syslog-ng, etc. Historical syslog data can often provide comprehensive details, like configuration changes, high momentary error rates, a sustained abnormal condition, etc., that cannot be shown using other forms of monitoring.

Proactive syslog monitoring and troubleshooting reduces trouble tickets because you detect and resolve issues before they become trouble tickets. A synchronous Web dashboard, alerting system, and log storage (with search options) are the basic features of any syslog monitoring tool. Moreover, integrating the syslog monitoring tool with other infrastructure management tools adds value to your syslog monitoring.

Wireless Body Area Networks

wbanWireless networking has become increasingly pervasive throughout our lives with the emergence of new communications technologies and techniques which have had a dramatic effect on the efficacy of the technology. As systems and ideas catch up with the tools available to them, one very interesting area which has been touched by wireless networking is that of the human body and its very immediate surroundings. Such networks are known as WBANs (Wireless Body Area Networks).

As a reasonably intimate application area, WBANs have found their primary usefulness to be in the medical arena. The demographics of the population of the world show it to be ageing fast as the baby boom generation moves up through the years. Around the world, governments and other interested agencies have begun to plan for the inevitable peak in the requirements for the care of the aged population. One potential advantage in dealing with the thorny problem they face is to use technology to leverage the effect of the limited resources they can bring to bear. Clinical areas such as Cancer Detection, Cardiovascular Diseases, Asthma Mitigation and Sleep Disorders can be positively impacted not to mention the broader areas the implants and wearable medical devices can bring to bear. Reaching further out, WBANs can also make a significant difference to the remote control of medical devices via telemedicine systems.

In short, the assistance provided by using WBANs is extremely significant however the adoption of the technology into the specific field has had to overcome some broad and significant challenges. These challenges can be broadly described as Architecture, Power Consumption, Data Rate and Security.

Lets take a look at how WBAN technology can be applied to the UK in the specific field of heart disease. Clearly heart disease is a leading cause of death for a significant percentage of the population. Appropriate and timely monitoring can prove to be a real asset in dealing with this condition and it is in this way that the benefits of WBANs can really be brought to bear. Systems have been developed such that, by the use of non intrusive miniaturised sensors, ambulatory monitoring of the most important metrics can be continued in real time as the patients go about their routines. The ubiquity of high speed mobile data networks in the UK means that, for the most part, this monitoring can continue uninterrupted for as long as is necessary. By carefully monitoring these vital signs, trained medical professionals can interpret the presence of problems, monitor deterioration and if necessary perform interventions.

In order to gain traction and mainstream acceptance in the United Kingdom, certain key issues had to be addressed. A hierarchical model for the architecture of WBANs has been developed such that  the devices are controlled by a central appliance known as a personal server. The model is flexible enough that it can be adapted to more specifically suit its use in specialised places such as a hospital or conversely broader scope areas out in the field.

Devices have had to be developed specifically for use in such an intimate way such that they do not exceed power outputs that are considered harmful to localised regions within the human body. A key measure known as the Specific Absorption Rate must not exceed the limits set out by various legislatures in the regions within which they operate. Institutional approval must be sought for each device that will operate in this specialised area. Furthermore, these specialised appliances, be they sensors or other devices must operate to very stringent limitations on their power consumption.

In order for the system to work within the context of a 21st century professional medical care system the governance framework around which the application is set out must be considerable. Lives can be lost if the system fails so it becomes imperative that systems failure modes and their consequences be carefully managed. Where there is potential for loss of life or serious non fatal consequences, steps must be in place to ensure that systems failure cannot take place.

pavAnother extremely important aspect which must be carefully managed is that of the security of medical WBAN systems. It almost goes without saying that, with systems that intrude into the most intimate areas of the human body that are charged with managing and effecting healthcare decisions, security is one of the most paramount concerns. Conventional network security, whilst strong, is by no means impenetrable. Appropriate systems of management, policy and operation need to run covalently with the key building blocks of security such as authentication, integrity and confidentiality. Complex encryption systems place demands upon processing as well as data rate overhead which serve to pull the design of the equipment away from the miniature. Broadly speaking therefore, a robust system must mesh together and operate flawlessly for the system to meet its mandatory requirements. Such standards require a strong governing entity to overarch the system and maintain its operation. The UK is well placed to provide this governing body and manage standards such as is necessary.

Looking contrastingly at Uzbekistan, where heart disease is a more significant issue, it becomes necessary to consider whether the resources available can ensure the necessary standards are met. It becomes perhaps necessary to rethink whether any of the standards which are necessarily adopted in an idealised situation such as is available in the UK can be relaxed. Standards of governance and their implementation and control require significant budget. Given the contrasting fiscal limitations in play in Uzbekistan one wonders perhaps if such actions and activities are appropriate.

In addition, looking at the figures for the penetration of networked data communication within the country, one also wonders if the infrastructure is in place to support such ambitions. One of the key unique selling points of the technology and its application is the ability for it to continue to operate with near ubiquity. In a country where the telecommunications infrastructure renders this nigh on impossible, it would seem to render the argument in favour of using the technology moot. Looking at both arguments it is therefore probably not a suitable technology for use in countries such as Uzbekistan with insufficient network infrastructure and very limited health budgets, tempting though the technology is.

WBANs present health professionals with unique opportunities to enhance medical care to levels previously unheard of and probably unachievable. With proper and effective management systems in place they represent a fantastic fillip to the broader toolset of medical practitioners. They will undoubtedly play an increasing part in health systems for many years to come.