Bandwidth Fundamentals for Video Surveillance

Bandwidth is the most fundamental element of computer networking for video surveillance systems. Because video surveillance can consume an immense amount of bandwidth and because variations in bandwidth load of surveillance cameras can be so significant, understanding bandwidth for video surveillance is critical. Bandwidth is typically measured in bits (e.g., 100Kb/s, 1Mb/s, etc.). A bit is the most fundamental unit of bandwidth and storage. You should be comfortable measuring the bandwidth, in bits, on your computer.

On your computer, it typically shows bandwidth being received by and bandwidth being sent out from your computer (as when you watch a video on youtube, you are receiving bandwidth and when you send an email you are transmitting bandwidth). These are also known as download and upload speeds respectively.

Sometimes, we might want to know what bandwidth is being used by one specific camera or on a VMS server or NVR. Exactly how this is performed differs from system to system and camera to camera, so users should consult their manufacturer's documentation to see exactly how it is performing.

In video surveillance, bandwidth is typically measured in bits but sometimes measured in bytes, confusing. 8 bits equals 1 byte, so someone saying 40 megabits per second and another person saying 5 megabytes per second means the same thing but is easy to misunderstand or mishear.

Bits and bytes both use the same letter for shorthand reference. The only difference is that bits use a lower case "b" and byte uses an upper case "B". You can remember this by recalling that bytes are bigger than bits. We see people confuse this often because at a glance they look similar. For example, 100Kb/s and 100KB/s, the latter is 8x greater than the former.

We recommend you use bits when describing video surveillance bandwidth but beware that some people, often from the server/ storage side, will use bytes. Because of this, be alert and ask for confirmation if there is any unclarity.

It takes a lot of bits(or bytes) to send a video. In practice, you will never have a video stream of 500b/s or even 500B/s. Video generally needs at least thousands or millions of bits. Aggregated video streams often need billions of bits.

The common expression/ prefixes for expressing a large amount of bandwidth are:

1- Kilobits, is thousands, e.g., 500kb/s is equal to 500,000b/s. An individual video stream in the kilobits tends to be either low resolution or high resolution or low frame or high frame compression.

2- Megabits is millions, e.g., 5Mb/s is equal to 5,000,000b/s. An individual IP camera video stream tends to be in the single-digit megabits (1 Mb/s or 2 Mb/s or 4Mb/s are fairly common ranges). More than 10 Mb/s for an individual video stream is less common, though not impossible in super-high-resolution models (4K, 20MP, 30MP, etc.). However, 100 cameras being streamed at the same time can routinely require 200Mb/s or 300Mb/s, etc.

3-Gigabits is billions, e.g., 5Gb/s is equal to 5,000000,000b/s. One rarely needs more than a gigabit of bandwidth for video surveillance unless one has a very large- scale surveillance system backhauling all video to a central side.

BANDWIDTH TUTORIAL FOR IP VIDEO SURVEILLANCE SYSTEMS

At the time of using IP cameras and video management systems, understanding the primary or basics about bandwidth availability and demand is critical to plan, designing, and deploying systems. everybody and every company in this industry should have a knowledge and understanding of the primary or basics as bandwidth is a critical factor in video surveillance.

BANDWIDTH AVAILABILITIES:- To determine and address bandwidth availability, you firstly need to specify which locations you are communicating between. The most important factor in determining how much bandwidth is available is whether or not you need connectivity between two different buildings. For instance:

1.  In the same building- lots of bandwidth: 70Mb/s to 700Mb/s of bandwidth is generally available.
2. Between different buildings- scare bandwidth: 0.5Mb/s to 5Mb/s of bandwidth is generally available.
3. 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 in 90 percent or more cases. But there is some exceptional some times:

• 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 telecom or research development company, more bandwidth can be available.

DIFFERENT BUILDINGS: The key driver in bandwidth availability is the cost increase of deploying networks between buildings. Generally referred to as the WAN, this type of bandwidth is usually provided by telecommunication companies. One common example is a cable modem or DSL, which can provide anywhere from 0.5 Mb/s to 5Mb/s at Rs. 1300 to 1500 per month. Another example is a "T1", which provides 1.5Mb/s for about Rs 18000 to 36000 per month. Above this level, bandwidth generally becomes very expensive. In most locations, getting 10Mb/s of bandwidth can cost thousands per month.

SAME BUILDING: By contrast, bandwidth inside of the buildings or campuses is quite plentiful because the install costs are quite low. Non-technical users can easily set up a 1000Mb/s networks inside the building (LAN) for less than 60000Rs installation cost with no monthly cost or rent or expenditure. The cost or expenses of deploying networks in buildings are very low because there are minimal to no construction expenses. By contrast, inside a building, the cables can often be quickly and simply finished by the ceiling.

WIRELESS:- A lot of discussion about wireless exists but wireless will not provide significantly greater bandwidth nor significantly better cost than DSL or cable modem. As such, wireless will not solve the expense and limitation of bandwidth between buildings. Wireless has benefits for mobility purposes and connecting to remote locations that DSL or cable modem cannot cost-effectively serve. Simple point to point wireless links have become inexpensive but are limited in where they can be used. These can be used only when a clear line of sight is available. This helps when you want to locate a camera 100 meters away in a parking lot but not if you want to transmit across the city.

HOW MUCH BANDWIDTH DO IP CAMERAS CONSUME:- For the bandwidth consumption of an IP camera, used 1-2Mb/s as a rough rule of thumb. Many factors impact total bandwidth consumption. You can certainly stream an IP camera as low as 2Mb/s and the other has high as 6Mb/s. In the year 2012, the most typical IP camera being deployed are HD using the H.264 codec at about6-10 fps. With this configuration, bandwidth consumption will be in the range 1-2Mb/s. Of course, the more resolution and greater frame rate you want, the more bandwidth will be used.

CSGOCO has been a well-established organization since 2012 and has a reputation for providing CCTV camera installation and maintenance services in Kolkata. Our Service technicians have already successfully completed several projects. If you need any kind of query, visit our website and call us.