GigE Vision – A Clear Standard

July 19, 2018 at 8:00 AM

 

As big data has gotten bigger and bigger, so have vision applications. GigE Vision is a global interface standard designed to support the transmission of high-speed video and related control data over Ethernet networks that include GigE, 10 GigE and 802.11 wireless networks.

 

This standard was developed using the Gigabit Ethernet communication protocol and provides fast image transfer using readily available Ethernet cables over extended distances. GigE Vision is capable of fast, high-bandwidth transfers of large images in real time at 125 MB/s and up to 100 meters in length. With the use of standard Cat5e and Cat6 cables and connectors, using GigE Vision is cost effective, highly scalable and allows for simple integration by using existing Ethernet infrastructures.

 

Managed by the AIA, a trade association for the machine vision industry, the GigE Vision standard was introduced in 2006 and has since been adopted globally, with most major industrial video hardware and software vendors having developed products that are GigE Vision-compliant. By following the same standard, products from different vendors are all interoperable. This means frame grabbers, embedded hardware interfaces, cameras, video servers, video receivers control applications and management entities can all work together seamlessly using a common Ethernet platform.

 

Much like USB3 Vision, GigE Vision relies on GenICam, a generic programming interface for different types of cameras, to access and control features in cameras and other imaging devices that are compliant. The simplicity of installation and high performance specs of GigE Vision makes it ideal for industrial applications. The standard is also used in telecom, military, data communications and machine vision applications.

 

GigE Vision is currently at version 2.0, which includes non-streaming device control, faster streaming over 10 Gig Ethernet and link aggregation. Version 2.0 is ideal for multi-camera systems and introduced the Precision Time Protocol (PTP) that enables cameras to be activated at the same time and Trigger-over-Ethernet without the need for an I/O cable. It also allows for multi-camera systems to be precisely synchronized, compressed images to be transmitted and enhanced support for multi-tap sensors. With all of its capabilities and benefits, GigE Vision has proven to be a boon in the world of vision applications.

 

The Full Spectrum of Wireless Communications Protocols and Standards

March 1, 2018 at 8:00 AM

 

The IoT is the driving force behind most wireless technology today. Everything including cars, smart homes, businesses and cities will be connected by the IoT. Plus, an estimated 300 million smartphones are slated to have artificial neural network (ANN) learning capabilities that would enable functions such as navigation, speech recognition and augmented reality.

 

With all the wireless technology rolling out and market demand for wireless communications applications continuing to grow, the development of different wireless technologies is also exploding to meet that demand. In fact, there are so many new technologies emerging that some directly compete with one another and frequencies overlap.

 

Many protocols are in accordance with IEEE 802.11 standards. The IEEE 802 LAN/MAN Standards Committee (LMSC) develops the most widely known wired and wireless standards, which encompasses local and metropolitan area networks. The fundamental IEEE standard of 802.11.n had of a minimum of 31 amendments through 2016, with more in the process. These cover everything from Ethernet, wireless LAN, virtual LAN, wireless hot spots, bridging and more.

 

Other IEEE standards include:

 

-    IEEE 802.15.4 for Simplified Personal Wireless and Industrial Short-Range Links

-    IEEE 802.15 Wireless PAN

-    IEEE 802.16 Broadband Wireless (WiMAX)

-    IEEE 802.22 for Wireless Regional Area Network (WRAN), with base station range to 60 miles

-    IEEE 802.23 for Emergency Service Communications

 

802.11 wireless technology began when the FCC released the industrial, scientific and medical (ISM) radio bands for unlicensed use. The ISM bands were then established in 1974 by the International telecommunication Union (ITU).

 

These are the frequency allocations as determined by the ITU:

 

Min. Freq.

Max. Freq

Type

Availability

Licensed Users

6.765 MHz

6.795 MHz

A

Local Acceptance

Fixed & Mobile Service

13.553 MHz

13.567 MHz

B

Worldwide

Fixed & Mobile Service except Aeronautical

26.957 MHz

27.283 MHz

B

Worldwide

Fixed & Mobile Service except Aeronautical & CB

40.66 MHz

40.7 MHz

B

Worldwide

Fixed, Mobile & Earth Exploration/Satellite Service

433.05 MHz

434.79 MHz

A

Europe

Amateur & Radiolocation Service

902 MHz

928 MHz B

B

Americas

Fixed, Mobile & Radiolocation Service

2.4 GHz

2.5 GHz

B

Worldwide

Fixed, Mobile, Radiolocation, Amateur & Amateur Satellite Service

5.725 GHz

5.875 GHz

B

Worldwide

Fixed-Satellite, Radiolocation, Mobile, Amateur & Amateur Satellite Service

24 GHz

24.25 GHz

B

Worldwide

Amateur, Amateur Satellite, Radiolocation & Earth Exploration Satellite

61 GHz

61.5 GHz

A

Local Acceptance

Fixed, Inter-satellite, Mobile & Radiolocation

122 GHz

123 GHz

A

Local Acceptance

Earth Exploration Satellite, Inter-Satellite, Space Research

244 GHz

246 GHz

A

Local Acceptance

Radiolocation, Radio Astronomy, Amateur & Satellite Service

 

In addition to IEEE standards, other technologies have broken away from IEEE and made the move to special trade organizations and even changed their names. Plus, there is a slew of short range communications standards vying for dominance, including ANT+, Bluetooth, FirstNet and ZigBee. No matter what your wireless communication application is, rest assured that there are plenty of standards and protocols to refer to when designing your wireless network.

 

Wireless Infrastructure 101

November 23, 2017 at 8:00 AM

 

You would be hard pressed to find a business, industry or home that doesn’t use wireless communication in some way. We depend on wireless networks used by our mobile devices, laptops, tablets and gaming systems to keep us connected, entertained and informed every day. Here, we’ll look at indoor and outdoor wireless infrastructure design considerations.

 

Frequencies

 

For wireless communication to work, radio frequency (RF) and microwaves are used to transmit voice, video and data. Radio frequencies are usually used in wireless networks, they range from 3 kHz to 300 GHz and are also used for AM broadcasting, navigational beacons and shortwave radio. Microwaves range from 300 MHz to 300 GHz and are typically used for television, FM broadcasting, aviation communications, and radar and satellite links. Most home, business and government networks operate on the Industrial, Scientific and Medical (ISM) frequency bands that range from 900 MHz to 5 GHz. The ISM band frequencies incorporate many of the IEEE 802.11wireless standards.

 


Design Considerations

 

When designing a wireless network, you must always take into consideration the environmental variables in the installation area that will or could affect network performance.

 


Indoor RF Wireless Networks

 

During installation or expansion, indoor networks present a special set of factors to consider. Most wireless access points and routers have a typical range capability specified by the manufacturer. But these ranges are based on having clear line of sight, which requires an unobstructed view of the antenna from the remote point in the link. Unfortunately, this is not the case in most indoor installations, there is usually some type of obstacle present. For example, signals typically will not penetrate concrete walls and the other building materials such as metal studs, aluminum siding, foil-backed insulation, pipes, electrical wiring and furniture. All of these common obstacles can reduce signal range and affect the coverage area. Plus, other wireless equipment such as cordless phones, microwave ovens, radio transmitters and electrical equipment can cause interference and decrease the signal range.

 


Outdoor RF Wireless Networks

 

Outdoor wireless networks face many of the same challenges as indoor networks, such as reflections and multipath. Having a clear line of sight is also critical for an outdoor network, trees and leaves can obstruct 802.11 frequencies and block the signal completely. A site survey is recommended before an outdoor wireless network is deployed, it might also be necessary to clear obstacles.

 

To help you plan and design your wireless network, we offer a series of wireless calculators to get you started.

Standards Showdown: 802.11 Standards Side-by-Side

July 20, 2017 at 8:00 AM

 

The IEEE is almost always working on another new amendment to the 802.11 Wi-Fi standard. We now have nearly as many 802.11 standards as there are letters in the alphabet, and keeping them straight can get confusing. Fortunately, we’ve compiled a comprehensive list of all of the 802.11 standards, old and new, for easy reference. 

 

RF Antenna FAQs

June 22, 2017 at 8:00 AM

 

 

Antennas are critical components to any wireless network, so having a good grasp of antenna technology can be very important for anyone engineering, designing or managing a wireless network. With so many antenna options and so much information to digest, it’s no wonder people have a lot of questions when it comes to antennas. Here, we’ll highlight some of the questions we’re asked most frequently.

 

How do I choose the correct Wi-Fi antenna? 

There are two main types of antennas - Directional and Omni-directional:

          

-   Directional antennas emit an RF signal in a focused beam, like how a car headlight focuses light in one direction. They are great if your application is a  point-to-point Wi-Fi link. For example, if you’re transmitting a signal from one building to another, you would use a directional antenna.

 

-   Omni-directional antennas radiate an RF signal in a 360-degree pattern. These antennas are ideal if you need the Wi-Fi signal to cover a 360-degree radius.

       

-   If you have a point-to-multipoint application, such as a campus environment, using a combination of directional and Omni-directional antennas would be your best bet.

 

What is antenna polarity?

Antenna polarity is the orientation of the radio wave’s electric field with respect to the Earth's surface. Antennas can be vertically polarized, horizontally polarized or a combination of the two. For more information, check out our antenna polarization blog post.

 

What is antenna gain? 

Antenna gain is a relative measure of an antenna’s ability to direct or concentrate radio frequency energy in a particular direction or pattern. Antenna gain is typically measured in dBi or dBd. Click here for more info.

 

What is 802.11? 

802.11 is an IEEE standard for implementing wireless local area network (WLAN) communications in the 2.4, 3.6 and 5 GHz frequency bands. There are numerous 802.11 standards and new versions continue to be developed. Existing standards include 802.11a, 802.11b, 802.11g, and 802.11n, 802.11ac, 802.11ac Wave 2, 802.11ah, 802.11ax, 802.11ay and 802.11af.

 

What is a decibel (dB)? 

A decibel (dB) is a unit of measurement for the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale. Decibels are commonly used in radio and sound measurement. One decibel is 1/10 of a Bel.

 

What is dBi ? 

Decibels-isotropic (dBi) are decibels relative to an isotrope. This unit of measure defines the gain of an antenna system relative to an isotropic radiator at radio frequencies. 

 

What is an isotrope? 

A theoretical isotrope is a single point in free space that radiates energy equally in every direction, similarly to the Sun.

 

What is frequency? 

Frequency is the number of cycles of alternating current in one second. It is measured in hertz (Hz).

 

What is a microwave? 

A microwave refers to all radio frequencies above the 1 GHz range. They are shorter than normal radio waves but longer than infrared radiation. Microwaves are used in radar, communications, for heating in microwave ovens and in various industrial processes.

 

What is multipath interference? 

Multipath interference is when signal reflections and delayed signal images interfere with the desired, un-delayed, larger signal. It causes picture ghosting in over-the-air analog TV and errors in digital transmission systems.

 

What is path budget?

Path budget is a mathematical model of a wireless communications link. It takes into account a wide variety of factors that can affect operating range and performance. Path budget is sometimes referred to as "link" budget.

 

What is path loss? 

Path loss is the weakening of a signal over its path of travel. This can be caused by factors such as terrain, obstructions and environmental conditions. It is measured in decibels.

 

What is fade margin? 

Fade margin is the loss of signal along a signal path caused by environmental factors such as terrain, atmospheric conditions, etc. It is measured in decibels.

 

What is a point-to-point network? 

A point-to-point network is a communications channel architecture that runs from one point to another. Directional antennas would be used in a point-to-point wireless link.

 

What is a point-to-multipoint network? 

A point-to-multipoint network architecture runs from one point to several other points. For this type of network, you would use both Omni-directional and directional antennas.

 

What is radio frequency? 

Radio frequency (RF) is typically a frequency from 20 kHz to 100 GHZ. RF is usually referred to whenever a signal is radiated through an enclosed medium, like a transmission cable or air.

 

What is a radio wave? 

A radio wave is an electromagnetic wave of a frequency used for long-distance communication. It is a combination of electric and magnetic fields varying at a radio frequency and traveling through space at the speed of light.

 

What is very-high frequency? 

Very high frequency (VHF) is the designation for radio waves in the range of 30 to 300 MHz.

 

What is ultra-high frequency? 

Ultra-high frequency (UHF) designates radio waves that are in the 300 to 3,000 MHz range.

 

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