Media Converter best for Surveillance Network

Media Converter best for Surveillance Network

Over the years, there has been a growing popularity of Video based Ethernet networks, resulting in the increasing use of Ethernet switches in the video network infrastructure.

Many types of video security and surveillance networks that are designed for applications in different environments. Analog video network and IP video network are the two most commonly used types for security and surveillance video transmission.

While IP video is more advance and can provide better image quality and network performance in large scale. The biggest character of IP video surveillance network is that every camera has its own IP address to tell itself from the others in the whole video network. Currently, with the demand for higher transmission speed, image quality and longer transmission distances, fiber optic cables are widely used in the video network. Thus, in both of the two surveillance networks, media conversion are necessary, like conversions between fiber and copper or video to fiber. The following will offer the cabling solutions that using media converters.

Video Media converter is a simple networking device that enables you to interconnect networks or network devices with different speeds, operation types, modes and media types. And the most common type usually works as a transceiver, converting the electrical signals in copper unshielded twisted pair (UTP) network cabling to light waves used for fiber optic cabling. It is essential to have the fiber optic connectivity if the distance between two network devices is greater than the copper cabling's transmission distance. Since media converters are IEEE compliant devices, they implement IEEE data encoding rules.

What is the

SFP module?

The small form-factor pluggable (SFP) is a compact, hot-pluggable transceiver used for both telecommunication and data communications applications. The form factor and electrical interface are specified by a multi-source agreement (MSA).

Media converter?

A fiber media converter is a simple networking device that make it possible to connect two dissimilar media types such as twisted pair with fiber optic cabling. Twisted pair cable, coaxial cable and other copper cabling can only support limited length before signal becomes too weak. Main application area is in security surveillance.

Why Best:

Ease of Use and High Availability

The SFP ports are widely used in the Gigabit Ethernet and the Fiber channel to provide a flexible and cost-saving solution for the enterprise networks and data centers. SFP port available in Enterprise Gigabit Ethernet Switcher. During the troubleshooting entire network will be down for time being.

Configuring and installing redundant solution of media converter is much easier to handle and to manage than higher-layer devices. And it will makes the troubleshooting easier if you add management functions to the media converter.

Proprietary

SFP modules are vendor dependent and switch is not available or that part number switch manufacture is stopped. In that case whole network switches needs to be stopped.

Media Converter is available, it can change any time. Its biggest advantage of this product.

EMI Emissions

The heat and EMI emissions are one of the biggest problems related to SFP devices.

No Such pain with media Converter.

Flexibility and Simplification

Wonderfull performance with LAN without protocol transparency with 850 nm and 1300 nm multimode fiber and 1310 nm and 1550 nm single-mode fiber.

It is of much flexibility for media converter to combine copper with 850 nm and 1300 nm multimode fiber and 1310 nm and 1550 nm single-mode fiber. With protocol transparency, it can be applied in anywhere in the local network or remote network whether it's a LAN, WAN or the MAN environment.

Handling Warning

Copper SFP are static sensitive. To prevent damage from electrostatic discharge (ESD), it is recommended to attach an ESD preventative wrist strap to your wrist and to a bare metal surface whenever you install or remove a Copper SFP module.

No such warning with media converter.

Safety Warning

Only trained and qualified personnel should be permitted to install or replace.

No such personnel required.

Spaceing

SFP Module takes up less space at Network Switch port.

Media converter  takes Little more space.

Powering

SFP Module Take power from Enterprise Ethernet Switch.

Media converter derives power from the switch it's plugged into. (Media converter requires a separate AC power outlet.)

Cost Reduction

Compared with the hybrid media switches, the cost of media converters with cost-effective Ethernet switches is much lower. This type of media converter solution can cost significantly less than that relies on higher-layer devices such as routers or switches.

Biggest advantage in this type of topology is where network consist of more than hundred nodes network. Fault point is reducing to switch only.

Analog Video Network Cabling Infrastructure

In a typical analog video network (shown in the above picture), analog CCTV cameras are connected to a central management room or devices (VCR—video cassette recorder or DVR—digital video recorder) via coaxial cables. If the camera has PTZ (Pan-Tilt-Zoom) function, an additional controller is added.

As mentioned, the performance and the transmission distance are limited by using copper cables. To connector more fixed analog cameras and PTZ analog cameras, fiber optic cable should be introduced to this typical network. Then fiber media converters are the best solutions. The following picture shows the basic structure or an upgraded version of a typical analog video structure which using fiber optic cable in this network.

To connect the fixed analog cameras to the server room, a pair of fiber media converters should be added between the server room and cameras. Video signals will be transmitted into fiber optic signals. For analog PTZ cameras, there are two types of signals should be converted into fiber optic signals, one for video and one for data. Thus, two different media converters or a fiber media converter that covers the two functions should be installed.

It is known that fiber media converters should be used in pairs. As one of the media converters is in deploy on the fiber end that near the camera, the other one should be deploy on the other fiber ends that near the server room. For better management, all the fiber media converters at the fiber end near the server room could be installed in a managed fiber media converter rack chassis.

IP Video Network Cabling Infrastructure

In a typical IP video surveillance network (shown in the above picture), IP cameras are connected directly to the local area network and transport video across the IP network via UTP cabling and switches. PoE IP cameras are also time-save and cost-effect solutions. Video can be recorded to any PC or server on the network. To introduce fiber optic cabling in to this typical IP video network, the method is similar to introducing fiber optic into an analog video network as described in the above paragraph.

In the following case (shown in the following picture), PoE IP cameras are used. A pair of PoE media converters should be installed on both ends of a length of fiber optic cable to achieve the conversion between video and fiber. At the computer side where the videos are recorded, a pair of Ethernet media converters should be installed. All of the media converters near the network switches can be set at a managed media converter chassis before the connected to the switches.

Biography:

Arindam Bhadra is an eSecurity professional 11yr + in this industry. He is a good freelance blogger. His blog is now No 1. Blog in India. 2.8L page viewer globally. Mr. Bhadra is an Electronics & telecommunication Engineer from IETE, New Delhi. He is a member of FSAI from 2011 & Go Beyond security from 2008. His blog arindamcctvaccesscontrol.blogspot.com focuses on security & Safety bloggers. Apart from his job, he loved to spend all his time with eSecurity & Safety technology and loves to help people. He is a Tech enthusiast and has written articles over the period on this blog. You can follow him on Facebook, Twitter, LinkedIn & Google+ etc.

This artical publish on May 2017 issue @ Safe Secure Magazine

Tukang Ngeblog | May 26, 2017 | Analog Video Network Cabling, blog, fiber optic cabling, IP Camera, IP Video Network Cabling, media converter, Media Converter best for Surveillance Network, SFP Module, SFP Port, transceiver

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Difference between Dynamic and Static IP

Difference between Dynamic and Static IP

The major difference between dynamic and static IP is that dynamic IPs change every time one connects to the internet, while static IPs remain the same.

Internet Protocols, also known as IP addresses is a 32-bit number that is usually assigned to a computer when it connected to a network, such as the Internet. The IP address works similar to an actual address and lets computers know where to send data packets. The network devices use these address in order to communicate with each other.

The IP address are made up of 4 parts of numbers that are divided by dots (.) So, a typical IP address will looking something like – 72.169.189.01.

Although, the IP Based product / computers communicate with each other using IP addresses, to make it easier to remember the internet uses DNS or Domain Name System. This DNS is sort of an address book that pairs names to IP addresses. For example, if one wanted to visit the Google website, they would type in www.google.com in the address bar. The DNS will look up the IP address (74.125.239.35) paired with this name and will ping that address. Their system will respond back and the webpage will load on your computer.

There are two types of IPs – dynamic and static IP addresses. The major difference between dynamic and static IP is that dynamic IPs change every time one connects to the internet, while static IPs remain the same.

There are limited amount of IP addresses that are available and for this reason, many companies assign dynamic IPs, unless a static IP is asked for. So, every time a device is connected to the Internet, the IP address can change. This also allows the limited number of IPs to become reused, making it more convenient.

Broadband connections today lease IP addresses and use the DCHP dynamic IP address system. This system is also often considered safer, since the IP is always changing it makes it more difficult to hack the computer. Static IPs are commonly used by companies or people who require a similar IP address. The can apply for a static IP by paying a fee.

Comparison between Dynamic and Static IP:

	Dynamic IP	Static IP
Full form	Dynamic Internet Protocol	Static Internet Protocol
Definition	The internet protocol will constantly change	The internet protocol will remain the same
Cost Effective	More cost effective	Less cost effective
Security Risk	Lower	Higher
Upload/Download Speed	Slower	Faster
Good for	Good for residential user and small business owners	Web servers, email servers and other Internet servers. Also, for VOIP, VPN, playing online games or game hosting

Tukang Ngeblog | May 14, 2017 | blog, DDNS, DHCP., Difference between Dynamic and Static IP, DNS, IP Camera, Static IP

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Wired or Wireless Analogue / IP CCTV cameras

Should I use wired, (cabled), or wireless analogue CCTV cameras? 

Choosing whether to use wired or wireless should be an easy decision.

There is only one question to ask: can I run a cable from my camera to recorder? If the answer is “yes” then you should always run a cable. If it is very difficult to cable then using a wireless camera may be an option, but only as a last resort.

Advantages of a cabled CCTV camera:

• Reliability – a physical cable will always be a lot more reliable than a wireless camera
• Less chance of interference – wireless cameras are prone to interference from many sources
• Less expensive – wired cameras generally cost less
• More professional – wireless cameras are only used in cheaper home systems
• Security – wired cameras are very difficult to jam. Wireless cameras can be blocked very easily by many different pieces of electronic equipment, eg: Wireless Access Points, mobile phones, microwave ovens, TV’s, two way radio equipment, gaming equipment, energy efficient lighting, the list goes on....
• Privacy – nobody else can see the cameras on your CCTV system, (CCTV means “Closed Circuit”), wireless cameras can be easily viewed by anybody with the right receiver, including your nosey neighbour!
• Generally better quality.
• Wired cameras can be connected to just about any CCTV recorder. Wireless cameras need specific wireless receivers, so they generally can’t be used from one system to another.
• Higher quality CCD image sensor, gives a clearer, better balanced picture. Many wireless cameras use cheaper CCD sensor, the images look murkier.
• Huge range of cameras to choose from, from Rs. 2500 up to Rs. 7500, wired cameras are available to suit just about any need, no matter how specialised.

Advantages of a Wireless CCTV Camera

• Easy for non-professionals to install
• Can work out cheaper – ideal for when capturing reliable, clear images isn’t important
• Easy to receive the images with cheap wireless receivers – your friends and neighbours can easily see the images from your cameras too.

So there you have it, the answer is clear, never, ever use a wireless camera solution if you can avoid it. If you need to use a wireless solution because of the long distance involved, then use wireless transmitter.

5 Important Locations in Your House That Need To Be Secured

1.     Front Door

Experts state that almost 34% of all intruders enter through the front door. You will have to select a safe location for this camera and preferably place a protective covering over it so that the risk of tampering is minimized.

2.     Back Door

Expert state that 22% of all intruders use the back door hence this is also an important spot to place a surveillance camera. Make sure you place it at a location where it is out of reach and safe from projectiles.

3.     Off-Street Windows

Burglars often use windows that are not visible from the streets, to break into houses as this reduces their chances of being caught. Motion detectors or glass-break detectors are designed to detect such break-ins.

4.     Backyards

These can be an ideal place for robbers or burglars to start off at night. Night-vision surveillance cameras can be used in backyards along with motion-sensor floodlights.

5.     Basement Stairs

Basements usually have multiple small entry points like hatches, doors or windows which can be used to sneak in. A motion sensing alarm can be placed here to help catch any intruders.

Whether, its wired or wireless, surveillance cameras play a central role in protecting you and your loved ones. Installing surveillance cameras at the right points and keeping on top of your security system is essential and necessary.

Tukang Ngeblog | October 01, 2016 | blog, cabled CCTV camera, CCD sensors, CMOS image quality, Intrusion alarm with CCTV, IP Camera, wireless analogue CCTV cameras

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Smartphone innovation will increase with 5G

Smartphone innovation will increase with 5G

Innovation in cellular and other supporting technologies as well as in applications will sustain the rate of smartphone improvements.

Press and industry analyst response to the recent announcement of the iPhone 7 has been lukewarm. For example, The Economist notes the “main novelty” is it no longer has a conventional jack for headphones. That newspaper reckons “after almost 10 heady years, dating from the release of the first iPhone in mid-2007, both growth and pace of innovation have slowed markedly in recent months.” I doubt the pace of innovation is really slowing or that this could ever be reliably determined over months rather than years. However, in conclusion, The Economist also wisely rejects “talk of an end to the smartphone era.”

Improvements under the hood

Whereas some smartphone innovations are very overt and revolutionary; others are not so apparent to consumers and are more evolutionary, but are at least as significant. The multitouch capabilities included in the first iPhone were literally very tangible and enabled access to regular web pages, as opposed to the repurposed content hitherto required for small displays with WAP browsers. The iPhone transformed browsing on a small device connected to the internet via Wi-Fi, but remained hobbled as a truly mobile device – six years after the introduction of the first 3G networks – with only 2G cellular connectivity and a maximum downlink speed of only around 150 kilobits per second achievable. Uplink speeds were much slower still.

Performance has improved enormously over the last nine years. LTE data rates are 1,000-times faster – at hundreds of megabits per second in the downlink, tens of megabits per second in the uplink, and latencies have reduced from several hundred milliseconds to tens of milliseconds. Ever-higher maximum cellular data rates achievable in the uplink and the downlink on the succession of iPhone models illustrates the gradual yet relentless improvements in cellular technology. For consistency over many years, the following chart includes fastest downlink data rates in device testing on commercial networks or considered likely following announcement of each new iPhone model, as indicated in contemporaneous analyst and press reports. Maximum speeds depend on latest technologies in devices and in network upgrades, which can take a year or so to roll out. Actual speeds are also affected by a user’s location and radio interference with other users nearby. For example, AT&T Mobility’s customers in New York and San Francisco suffered with slow speeds and poor availability following the introduction of the iPhone 3GS in 2009. Such problems are rarely so severe these days.

Exponential growth in downlink speedsOther fundamental device improvements include the number of cellular standards and frequency bands supported. The first iPhone was a single-mode GSM/GPRS/EDGE device. Over the years, CDMA, TD-SCDMA, LTE-FDD and LTE-TDD have been added to make iPhones multimode devices. Multiple frequency bands are also employed with each standard. In particular, large and increasing numbers of bands are required for LTE. Since the introduction of the iPhone 5 in 2012, with support for LTE in up to five bands, the number of LTE bands supported has increased to 23 bands in the iPhone 7. Squeezing more and more modes, bands and other cellular functions into smartphones and getting higher and higher levels of radio performance out of them is no mean feat. It requires major innovative efforts and accomplishments in various ways.

A lot of inspiration and perspiration

Cellular technology developments have included some relatively large step-changes, for example, with new air interfaces; but developments mainly arise in a series of many incremental improvements. Even generational upgrades can take years to deploy across networks before benefits can be fully enjoyed. Until at least the turn of the millennium, cellular technology improvements were overwhelmingly in supporting voice and the most basic data capability imaginable with a maximum of 140 characters per text message. Since then, innovations have been focused on exponentially increasing speeds and network capacity for data. Numerous new technologies have been developed and introduced in the last decade. Terminology for these includes dual carrier, carrier aggregation, inter cell interference coordination, coordinated multipoint and heterogeneous networks among many others which have collectively boosted spectral efficiency, increased end-user data rates, increased network capacity and lowered latency.

The development of these standard-essential technologies is a massive coordinated endeavor involving numerous companies. According to analysis by Signals Research Group on 262,773 submissions to five 3GPP working groups from 1999 through December 2014, 43,917 documents were approved for inclusion in standards. The approved documents include 3G only, LTE only, and 3G and LTE documents as well as submissions that fall outside all of these three categories – documents pertaining to GSM/GERAN or IP multimedia subsystems are examples. More than an estimated 1 million man-hours is spent actually in 3GPP working group meetings each year. However, working group activity is merely the tip of the iceberg. Mobile communications sector research and development investment is estimated at up to $100 billion per year. Much of that is in development of standard-essential technologies including 4G recently, and now also in 5G.

‘You ain’t seen nothing yet!’

Each successive new generation of cellular technology has been driven by increasing technology developments, innovation and adoption by wireless carriers and consumers. Following the rather disappointing data rates and lackluster adoption of 3G W-CDMA between 2001 and 2005, the pace of all the above increased with the introduction of HSDPA from around 2006, and then increased again with the introduction of LTE from around 2010. Industry enthusiasm for 5G is also great and so we should expect the rate of innovation to be maintained, not diminish, with the expected introduction of 5G toward the end of the decade.

Whereas demand for 5G will be dependent on new applications such as those in artificial intelligence and augmented reality, some of those applications will only be possible by the improved performance such as ultra-low latency and ultra-high availability, as well as higher data rates that 5G communications promises. Many innovations and improvements will be required for new types of devices and services such as with the “internet of things,” but smartphones will also be in the frontline.

Tukang Ngeblog | September 02, 2016 | 4G LTE, 4G Mobile, 5G, 5G Mobile, 5G Technology, Android remote view, blog, CDMA, GPRS, HSDPA, IP Camera, iPhone 7, LTE-FDD, TD-SCDMA

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Bandwidth Basics for IP CCTV Design

Bandwidth Basics for IP CCTV Design

When using IP cameras, Megapixel cameras, NVRs or even DVRs, understanding the basics about how much bandwidth is available and how much is needed is critical in planning, designing and deploying IP video surveillance systems. Copper Ethernet wiring (typically Cat-5, Cat-5e, Cat-6 or Cat-7) have a practical length limitation of 100 meters (or about 300 feet) between devices. To accommodate longer-length wired network connections, fiber can be used. 

This article is focused for a non-IT audience such as security managers, electronic technicians, sales and marketing folks.

How Much Bandwidth is Available?

To figure out how much bandwidth is available, you first need to determine what locations you are communicating between. Much like driving, you will have a starting point and destination. For example, from your branch office to your headquarters. However, unlike driving, the amount of bandwidth available can range dramatically depending on where you are going.

The most important factor in determining how much bandwidth is available is whether or not you need connectivity between two different buildings.

For instance:

In the Same Building: 70Mb/s to 700 Mb/s of bandwidth is generally available

In Different Buildings: .5 Mb/s to 5 Mb/s of bandwidth is generally available

The amount of bandwidth available going from your office to a co-worker's office in the same building can be 200 times more than the bandwidth from your office to a branch office down the block.

This is true in 90% or more cases. Note the following exceptions:

If these are different buildings but on the same campus, more bandwidth may be available.

If you are in a central business district of a major city, more bandwidth may be available.

If you are a telecommunications or research company, more bandwidth may be available.

Different Buildings

The key driver in bandwidth availability is the cost increase of deploying networks between buildings. Generally referred to as the Wide Area Network or WAN, this type of bandwidth is usually provided by telecommunications companies. One common example is cable modem or DSL, which can provide anywhere from 0.5 Mb/s to 5 Mb/s at Rs. 3000 to Rs. 5000 per month. Another example is a T1, which provides 1.5Mb/s for about Rs. 8000 to Rs. 16000 per month. Above this level, bandwidth generally becomes very expensive.

Many talk about fiber but fiber to the building is not and will not be widely available for years. Fiber to the home or to the business promises to reduce the cost of bandwidth significantly. It is very expensive to deploy and despite excited discussions for the last decade or more, progress remains slow.

Same Buildings

By contrast, bandwidth inside of buildings (or campuses) is quite high because the costs of deploying it are quite low. Non technical users can easily set up a 1000Mb/s networks inside a building (aka Local Area Networks or LANs) for low installation cost with no monthly costs. The cost of deploying networks in buildings are low because there are minimal to no construction expenses. When you are building a network across a city, you need to get rights of ways, trench, install on telephone poles, etc. These are massive projects that can easily demand millions or billions of dollars in up front expenses. By contrast, inside a building, the cables can often by quickly and simply fished through ceilings (not the professional way to do it but the way many people do it in deployments).

A lot of discussion about wireless (WiMax, WiFi, 3G, 4G etc) exists but wireless will not provide significantly greater bandwidth nor significantly better costs than DSL or cable modem. As such, wireless will not solve the expense and limitations of bandwidth between buildings. That being said, wireless absolutely has benefits for mobility purposes and connecting to remote locations that DSL or cable modem cannot cost effectively serve. The point here is simply that it will not solve the problem of bandwidth between buildings being much more expensive than bandwidth inside of buildings.

How Much Bandwidth Do IP Cameras Consume?

For the bandwidth consumption of an IP camera, use 1 Mb/s as a rough rule of thumb. Now, there are many factors that affect total bandwidth consumption. You can certainly stream an IP camera as low as 0.2 Mb/s (or 200 Kb/s) and others as high as 6 Mb/s. The more resolution and greater frame rate you want, the more bandwidth will be used. The more efficient the CODEC you use, the less bandwidth will be used.

For the bandwidth consumption of a Megapixel camera, use 5 Mb/s to 10 Mb/s as a rough rule of thumb. Again, there are a number of factors that affect total bandwidth consumption. A 1.3MP camera at 1FPS can consume as little as 0.8 Mb/s (or 800 Kb/s) yet a 5 megapixel camera can consume as much as 45 Mb/s.

What Does this Mean for my IP Video System?

Just like dealing with personal finance, we can now figure out what we can 'afford':

Between Buildings: We have 0.5 Mb/s to 5 Mb/s to 'spend'

Inside Buildings: We have 70 Mb/s to 700 Mb/s to 'spend'

IP cameras: Cost us 1 Mb/s each

Megapixel cameras: Cost us 5 Mb/s to 10 Mb/s each

Using these points, we can quickly see what combination of IP and megapixel cameras we can use between buildings or inside of buildings.

Inside of buildings, it is easy to stream numerous IP and megapixel cameras.

Between buildings, it is almost impossible to stream numerous IP and megapixel cameras.

Because of this situation, the standard configuration one sees in IP Video systems is:

A local recorder at each building/remote site. The local recorder receives the streams from the building and stores them.

The local recorder only forwards the streams (live or recorded) off-site when a user specifically wants to view video. Rather than overloading the WAN network with unrealistic bandwidth demands all day long, bandwidth is only consumed when a user wants to watch. Generally, remote viewing is sporadic and IP video coexists nicely with the expensive Wide Area Network.

The local recorder has built-in features to reduce the bandwidth needed to stream video to remote clients. Most systems have the ability to reduce the frame rate of the live video stream or to dynamically reduce the video quality to ensure that the video system does not overload the network and that remote viewers can actually see what is going on the other side. Generally, the live video stream is sufficient to identify the basic threat. In any event, bandwidth is generally so costly, especially the upstream bandwidth needed to send to a remote viewer, that this is the best financial decision.

Tukang Ngeblog | July 09, 2016 | 3G, 4G, Bandwidth IP Camera, blog, CAT-5, CAT-5e, Cat-6, IP Camera, IP Video System, WiFi, WiMax

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Bit Rate

Bit Rate For DVR, NVR & IP Camera

What are Bit Rates?

Let’s start with “what is a bit, and “why do I need to know?” A bit is short for “binary digit”, the smallest unit of information in computing. It takes 8 bits to make a byte of information. “Bit rate” refers to the number of bits of data transferred in a file over a set length of time usually measured in number of “bits per second” or “bps”.

Constant bit rate (CBR) and variable bit rate (VBR) are the main types of bit rate encoding. Scene complexity can vary significantly over several hours of recorded video, and the bit rate you select for recording will have an effect on image quality, bandwidth consumption, and hard drive storage. A complex scene with moving action, such as traffic on a city street, or a scene with a lot of contrasting colors, will affect image quality and bandwidth consumption more than a less complex scene, such as an interior room with very little action or movement.

Most NVRs and IP cameras let you choose either constant or variable bit rates for recording video, and this is why you “need to know” the difference.

Constant Bit Rate (CBR)

With constant bit rate encoding, a fixed bit rate and bandwidth is used throughout the entire encoded video file. With a constant bit rate, image quality may fluctuate over the course of the video stream because some scenes are more difficult to render than others. In order for the bit rate to remain constant, the video may be encoded with fewer bits in some places or more bits in other places resulting in inconsistent image quality. Since bandwidth consumption with constant bit rates does not vary, the file size is limited and more predictable than with variable bit rates.

You will most commonly use CBR to restrict the data flow to keep network utilization as low as possible. If you have 10 cameras set to 8000K (8 megabits) on a 10/100 LAN, you are using 80% of your available bandwidth. With CBR, you can set that bit rate down to 5000K and your utilization will be around 50%.

Pre-planning your security video storage requirements is easier with constant bit rate because the amount of data being recorded never changes.

Variable Bit Rate (VBR)

With variable bit rate encoding, a changeable bit rate and bandwidth is used throughout the encoded video file. The variability of bit rates allows for video to be recorded at a lower bit rate when the  scene on screen is less complex and at a higher bit rate when the scene is more complex. Complex scenes (such as moving traffic) require more data and greater bandwidth to maintain image quality  than less complex scenes such as a wall or hallway with very little movement or action. With variable bit rates, the quality of video is higher and more consistent throughout the video stream compared to constant bit rates, yet the file size is less predictable.

Image quality is better with variable bit rates than with constant bit rates, yet pre-planning your security video storage requirements is more difficult because the bit rate changes and more complex scenes will require greater bandwidth and storage.

Here’s a Quick Look at How Constant and Variable Bit Rates Compare:

Constant Bit Rates	Variable Bit Rates
Variable video image quality	Consistent video image quality
File size is predictable because bit rate and bandwidth consumption is fixed	File size is unpredictable because bit rate and bandwidth consumption varies
Greater compatibility with most systems (compared to variable bit rate)	Less predictable compatibility (compared to constant bit rate)
When to use: When you need to limit file size and the quality of video is less important.	When to use: When consistent image quality is critical and predicting or limiting file size is less important.

The best of both worlds is when the device allows you to set VBR with a ‘Cap’ or maximum allowed bit rate.

Here is a handy ‘Quick Reference’ for setting a constant Bit Rate in bits per second.

Low Activity
Compression	Frame Rate	VGA/D1	720P/1.3MP	1080P/3MP
H.264	25~30	768K	2000K	3000K
	15~20	512K	1500K	2000K
	8~10	386K	1000K	1500K
	2~5	256K	768K	1000K
MPEG4	25~30	1000K	3000K	5000K
	15~20	768K	2000K	4000K
	8~10	512K	1500K	3000K
	2~5	386K	1000K	2000K

Normal Activity
Compression	Frame Rate	VGA/D1	720P/1.3MP	1080P/3MP
H.264	25~30	1000K	3000K	5000K
	15~20	768K	2000K	4000K
	8~10	512K	1500K	3000K
	2~5	386K	1000K	2000K
MPEG4	25~30	1500K	4000K	6000K
	15~20	1000K	3000K	5000K
	8~10	768K	2000K	4000K
	2~5	512K	1500K	3000K

High Activity or PTZ on Tour
Compression	Frame Rate	VGA/D1	720P/1.3MP	1080P/3MP
H.264	25~30	2000K	4000K	6000K
	15~20	1500K	3000K	5000K
	8~10	1000K	2000K	4000K
	2~5	768K	1500K	3000K
MPEG4	25~30	3000K	6000K	8000K
	15~20	2000K	4000K	6000K
	8~10	1500K	3000K	4000K
	2~5	1000K	2000K	3000K

In the bit rate charts above, you will see 1000K / 2000K etc. These figures can be loosely translated into ‘megabits’ per second.

1000K = 1Mb | 2000K = 2Mb and so on.

(In the computing world you would actually use 1024K = 1Mb and 2048K = 2Mb, but since most CCTV devices won’t allow those exact numbers, we just round them down to the closest thousand.) These figures are important to familiarize yourself with to manage your network load.

For example – 1 camera running a high bitrate of 8000Kbps (8Mbps) is no problem on a 10/100 network. 10 cameras at that bit rate = 80Mbps. 80Mbps is 80% network utilization on a 10/100 LAN. This is enough to see visible slowdown on the network and may begin to cause problems.

Switch to a Gigabit LAN and that becomes 8% utilization. Always check the capabilities of the network you are installing on – this can save you from a lot of headaches. When using IP cameras, always use Gigabit routers and switches when possible.  Also, make sure your NVR is connected to a gigabit switch. Plugging your NVR in to a 10/100 switch will limit your NVR to a 100Mb connection.

And finally – here is a “loose rule of thumb” for setting a bitrate:

[image width] x [image height] x [framerate] x [motion rank] x 0.07 = [desired bit rate]

Where the image width and height is expressed in pixels, and the motion rank is a number between 1 and 4. 1 being low motion, 2 being medium motion, and 4 being high motion (motion being the amount of image data that is changing between frames.).

So for instance, if we take a 1280×720 video at 24 FPS, with medium motion (movie with slow camera movements, not many scene changes…), the expected ideal bit rate would be:

1280 x 720 x 24 x 2 x 0.07 = 3,096,576 bps => approximately 3000 kbps, or 3MB

Remember – bit rates are not “universal” – different cams will give different results due to variations in encoding methods, hardware, and environmental conditions. Watch for artifacts like “ghosting” or “smearing” of moving objects.

Ghosting = when someone moving across the image may appear transparent, or may have a “ghost” following them. The “ghost” is not always transparent and may look like two people overlapped.

Smearing = when a moving object causes objects around it to change in appearance or starts to become pixilated.

Pixilated = When objects become unclear – may appear as a “smear” or slightly out of focus. In worst cases you will begin to see blocks of similar colors instead of the object itself.

Tukang Ngeblog | October 03, 2015 | 1024K, 24FPS., bit rate, CBR Vs VBR, CBR vs VBR Surveillance Streaming, CVR, IP Camera, NVR, Thumb Rool of Bit rates, VBR

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