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.

Wired and Wireless Networks for the Energy Industry

September 14, 2017 at 8:00 AM

 

The energy industry is getting a lot of attention these days with more people talking about how we can better harness and use energy. Here, we’ll look at the energy industry and how all sectors, including oil, gas and renewable sources, are using wired and wireless networks to connect their operations.

 

Oil and Gas

 

Offshore oil platforms are exposed to water, salt, vibration and extreme temperatures. Although in many cases the communications equipment used on these rigs are housed in protective enclosures some equipment must be located in exposed areas where they are subject to environmental extremes. This includes IP cameras used for surveillance of the platform, plus the cabling and converters that link back to the central control room on the rig. Wireless sensors and controllers are also located throughout the platform and are linked by outdoor antennas, amplifiers and access points used to operate the rig.

 

In petroleum refineries, wired and wireless sensors are used to monitor and control process applications and provide real-time data that can warn of system issues. Many valves and controllers are linked to a serial or IP network, as well as security and surveillance equipment that are critical to operations.

 

Natural gas pipelines depend on communications networks to monitor the safety and efficiency of the pipeline, which can span hundreds of miles over harsh terrain and in remote areas. These networks allow for real-time data to be sent to the control room that can detect leaks and issues with pressure and temperature. IP based surveillance systems along the pipeline also require network connectivity to provide added protection.

 

Renewable Energy

 

Solar energy networks use wired and wireless connectivity for long distance control and monitoring of solar panel arrays. For example, serial data cables connect to the power meters on the panel, theses power meters are then connected to the Ethernet network via a device server and antennas wirelessly connect the power meters back to the control center for monitoring and control.

 

Hydroelectric power has modernized operations by implementing automated systems in hydroelectric plants. Many of these systems use Programmable Logic Controllers (PLCs) to control valves, motor starters, sensors and flood gate control systems that are critical to operations. Other systems use wireless networks to monitor and control the plant. Surveillance and security systems are also important in these plants to not only monitor for intruders, but also to visually analyze the dam and plant and watch for structural breakdown.

 

Monitoring wind turbines also requires wired and wireless networks. An industrial Ethernet switch allows signals to be sent to the turbine that change its speed and angle. Fiber optic cables connect the control center to multiple turbines over long distances for complete control of the wind farm and antennas are used to connect the local control center to a main control network.  

 

For more details on how wired and wireless technology is powering the energy industry, and how L-com’s products are being used, download our energy industry overview.

 

The Low Down on Low-Loss Coax Cables for Wireless Applications

August 17, 2017 at 8:00 AM

 

It may seem counterintuitive that a wireless network would need cables, but it’s true. The components of a wireless network, such as access points, amplifiers and antennas, all need cables to communicate with one another. Antenna cables introduces signal loss in the antenna system for both the transmitter and receiver. In order to reduce this signal loss, you need to either minimize the cable length, if you can, and use only low-loss or ultra-low-loss coax cable s in order to connect access points and amps to antennas.

 

Coaxial cable is one of the oldest signal cabling types and is still used today because it is robust and very good at carrying a signals over long distances. The term coaxial comes from the inner conductor and the outer shield sharing a geometric axis. The term "low-loss" refers to the cable's relative low-attenuation (loss) over distance. The general rule is that the thicker the cable is, the less loss of signal there will be over the length of the cable.

 

RG-style cables were the original standard for coaxial cable, but the signal in these cables degrades over longer distances. This isn’t an issue when covering short distances, but in a wireless application it is critical to maintain the signal strength throughout the cable and until it is sent out through the antenna. Thus, low-loss coaxial cable was created offering lower attenuation and better shielding, a much better solution for wireless systems than RG-style cables. Low-loss coaxial cables also use solid center conductors which provide lower attenuation than the stranded conductors found in some types of RG-style coax cables.

 

Low-loss coaxial cables are ideal for use in WLAN, Cellular, PCS, ISM and many other wireless communications applications. They are offered in multiple sizes with a three-digit “series” number designating the thickness of the cable and the low-loss properties. For example, 400-series low-loss coax is thicker and has less loss than 200-series, and 200-series is thicker and has less loss than 100-series. While the thicker cable will provide less loss, it will also be heavier and less flexible, though ultra-flex versions of the thicker series cables do offer more flexibility.

 

Here is a comparison chart for popular types of low-loss coaxial cables:

How Wired & Wireless Technology Is Helping Healthcare

June 29, 2017 at 8:00 AM

 

Healthcare is a hot topic right now. It is something that touches everyone’s lives at some point, though we might not think about the technology that goes into building healthcare devices and keeping hospitals running smoothly. Here, we’ll look at the healthcare industry and how technology is used in devices and to build communications networks to keep medical centers connected.

 

OEM Medical Devices

 

A medical device may only be as good as the parts that it’s made ofand if you’re ever in need of a defibrillator, you’re surely going to want it to have been constructed with quality parts. Medical manufacturers use all types of connectivity products to build medical devices, these include USB cables and adapters, HDMI, VGA and D-subminiature cables and adapters. For all of these parts, there are strict design requirements that must be met to comply with federal safety regulations.  We work with medical device OEMs around the world to provide solutions to fit their requirements to build medical devices that will perform when they’re needed most.

 

In-Building Wireless Networks

 

Many of today’s hospitals and medical facilities have replaced old-school patient charts with portable, wireless tablets to keep track of patient information and records. Thus, they depend on reliable cellular and Wi-Fi coverage to keep devices used by doctors and nurses connected, plus those used by patients and visitors. Distributed antenna systems (DAS), access points, RF amplifiers and low-loss coaxial cables are used to ensure that medical staff and patients can stay connected with seamless cellular and Wi-Fi coverage.

 

Medical Campus Networks

 

When a medical facility spans across several separate buildings, a high-speed communications network is needed to share vital information such as patient records and test results. Wireless point-to multipoint networks use directional and Omni-directional antennas to send wireless signals throughout the campus. If a wireless network can’t be used because Line of Sight conditions are less that optimal, a wired fiber backbone can be implemented to connect the buildings. In this case, an intricate network of fiber cabling, media converters, routers and Ethernet switches are employed to provide comprehensive campus-wide coverage.

 

Wired Infrastructure/Data Center

 

Within hospitals and medical centers there can be numerous floors that all need to be connected to a main data center. A wide variety of cabling and connectivity products are used to build this wired communications infrastructure from the ground up, running from the IDFs to the data center.  Category 5e/6/6a cables, OFNP and LSZH cables, server racks, patch panels, switches, routers and more are all used to build a high-speed, fault-tolerant medical communications network to keep every floor, device and user connected.

 

For more information on how wired and wireless technology is helping healthcare, and how L-com’s products are being used, read our full healthcare industry overview.

 

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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