Easy Answers to Your Top 5 Wireless FAQs

August 7, 2014 at 10:00 AM

 

 

If you know L-com, you know that we listen to our customers.


Over the years we have published many informative FAQs to help you get your job done. In this week’s post we have compiled our top 5 wireless FAQs to help you better understand different aspects of wireless networking, including antenna selection and operation, choosing the right WiFi amplifier for your network and more.


You’ll find that some of these FAQs are associated specifically with L-com’s products, while others are simply general knowledge that you can use and share!


 

What is a Distributed Antenna System (DAS)?

 

Often times a DAS uses RF directional couplers and/or wireless amplifiers to split and amplify a wireless signal from the source out to distributed antennas. A DAS can be designed for indoors or outdoors. This FAQ explains how a DAS system can be configured for both types of deployments. 

 

 

What is Antenna Polarity?

 

It’s simple. Click above to find out!

 

 

How do I choose the right WiFi amplifier?

 

When deciding which WiFi Amplifier to buy, there are several important options to consider: PoE, Frequency, Automatic Power Control (APC) and more. Take a look at our breakdown. 

 

 

 

 

 

How do I use a HyperLink brand Antenna?

 

Here we share some common WiFi antenna design considerations that explain which HyperLink brand antenna to use for specific wireless applications, including point-to-point and point-to-multi-point architectures.

 

Not sure which antenna is best for your application? Read on. 

 

 

Common Wireless Connectivity Terms

 

Test your knowledge of commonly used wireless terms, or refer to this extensive list when faced with a new project. Entries include Direct Sequence (DS), Effective Radiated Power (ERP), Attenuation, Wind Loading, Signal-To-Noise Ratio (SNR) and much more. 

 

Introducing 45° Angled Ethernet Cables, the Missing Link

July 31, 2014 at 10:00 AM

                             

                               

 

How is your IT closet or data center looking?

 

Does it look like a bowl of spaghetti with cables intertwined every which way, and no end or beginning in sight?

 

Or maybe it’s not so extreme, and you only have a few stray cables or strained connections. Either way, there is probably some room for better cable management. 

 

90 degree angled cables (which you might have already seen in use) are a common solution used in many IT connectivity applications where dense patching occurs.

 

However, in some instances 90 degree angled cables many not do the trick because of different port orientations and overcrowding.

 

Now there also exists a new breed of angled cable that is just as effective as its right angled counterpart, offering an alternative angle where a 90 degree won’t fit. 

 

Introducing the 45 degree angled Ethernet cable:

 

These unique, patent pending cables are perfect for use in data centers or high density patching applications. They add a professional look to patch panels with neatly organized cable exits to the sides of any RJ45 patch panel.

 

Here’s why we stand behind them:

 

• They offer true Category 5E or 6 performance while maintaining a 45° bend

• They provide a solution in tight and confined spaces or in crowded patching applications

• The angled, low profile boots make it easy to horizontally stack connectors

 

L-com’s angled Ethernet cables are currently offered in both Cat 5E shielded or non-shielded and Cat6 shielded or non-shielded.

 

 

 

So how do they work? 

 

These angled cables employ a specialized channel separator and load bar that achieves category performance while maintaining a smooth bend. The patent-pending design reduces cable stress and provides a clean appearance without restricting access.

 

45 degree angled Ethernet cables could be particularly beneficial for IT departments that utilize high density patching of Ethernet cables since L-com’s exclusive design efficiently transitions network cabling to the rack sides.  When used with the high density Ethernet ports that are common on switching gear and patch panels, these cables are easy to latch or unlatch. 

 

With L-com’s commitment to cable performance, IT professionals can also be confident their network cables are providing optimum performance. 

 

Additional features of L-com’s angled Ethernet patch cables include:

 

• 24 AWG stranded conductors provide cable flexibility

• Both left and right orientations are available and all stock options are left or right angled to a standard straight RJ45 connector

• Shielding options to protect against EMI/RFI

• Available in five cable length variations: 1, 3, 5, 7 and 10 feet

• Custom lengths and connector versions are available

 

Another advantage of these cables is that they are available in a variety of colors: blue, black, gray and red. Various colors can be used to distinguish between different network functions, which helps to speed troubleshooting and reduce human error.

 

Are you already using 45 degree angled cables in your application? Tell us about your unique configuration in the comment section below. 

Posted in: Wired

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Can You Define Antenna Gain?

July 24, 2014 at 10:00 AM

 

"What is gain?" 

 

Many of our customers ask us this question. 

 

In fact, it has become so common that we created a Wireless Glossary to explain “gain” along with other common wireless terms.

 

But, the term “gain” is tricky to define, so we're going to dig into it a bit more here.

 

One of the major parameters used in analyzing the performance of radio frequency (RF) communication is the amount of transmitter power directed toward an RF receiver.

 

This power is derived from a combination of:

 

1.Transmitter power

2.The ability of the antenna(s) to direct that power toward an RF receiver(s)

 

 

 

Directivity

 

The directivity of the antenna is determined by the antenna design. Directivity is the ability of an antenna to focus energy in a particular direction when transmitting or to receive energy better from a particular direction when receiving. To determine the directivity of an antenna, we need a reference antenna with which to compare our antenna's performance.

 

Omni Directional:
360° Coverage

Directional:
Focused Coverage

 

 

Over the years there have been several different reference antennas used to determine directivity; however, today an isotropic radiator is preferred as the standard antenna for comparison. The isotropic antenna transmits equal amounts of power in all directions (like a light bulb).

 

To increase the directivity of a bulb's light (or the antenna's energy)- similar to a flash light or automobile head lamp in this example- a reflector (antenna) is added behind the bulb. At a distance the light bulb now appears to be much brighter in the light beam. The amount that the bulb appears brighter compared to the bulb without a reflector is the directivity of the reflector (antenna).

 

When directivity is converted to decibels we call it the “antenna gain” relative to an isotropic source (dBi). Typically the higher the gain, the more efficient the antenna's performance, and the farther the range of the antenna will operate. For every 6 dBi in gain, you double the range of the antenna.

 

It should also be noted that many factors need to be considered when selecting the "best" antenna for the desired application, and it’s best to discuss any antenna selection with someone knowledgeable in RF radiation and antenna performance. L-com has experts to help you make the best selection for performance and price to fit your application.

 


 

Helpful definitions to summarize our topic:

 


Antenna Gain: A relative measurement of an antenna's ability to direct or concentrate radio frequency energy in a particular direction or pattern. This measurement is typically measured in dBi (Decibels relative to an isotropic radiator) or in dBd (Decibels relative to a dipole radiator).

 

Isotropic Radiator: is a theoretical single point in space that radiates energy equally in every direction similar to the Sun radiating its light. The isotropic radiator exhibits the same magnitude or properties when measured in all directions. It has no preferred direction of radiation. It radiates uniformly in all directions over a sphere centered on the source.

 

 

Check out some of our best selling antennas!                                                                     

 

 

6 Ethernet Myths Revealed

July 17, 2014 at 10:00 AM

 

Let's challenge your Ethernet knowledge.

 

Did you know that Ethernet cabling is one of the most common cabling types? It's almost as common as electrical wiring! Ethernet is often run through walls, ceilings, under floors, and usually branches in a star topography from a central wiring closet.

 

Since it's so popular, we've put together some common assumptions about Ethernet cabling that are worth investigating.

 

See if you know the correct answers: 

 
 
 
 
 

 1. Myth or Fact:  The color of the cable jacket indicates what kind of signal the cable carries.

 

Myth! Ethernet is Ethernet, so there aren't different signal types. Although, there may be different speeds running in the same building. Usually, your IT department will use different colored cables to keep track of where the cable goes. This makes it a lot easier in the wiring closet to identify cables.

 
 
 
 

2. Myth or Fact:  If I run cables that are EIA/TIA 568 B standard, I cannot use any cables wired to the EIA/TIA 568 A standard on the same network.

 

Myth! The EIA/TIA 568 A and B standards are actually both straight-through pinned. They are pin to pin, 1 through 8. The difference is in the color code of the wires inside the jacket. These standards were originally set to improve network performance and consistency between manufacturers. 

 

For this reason, if you mix A and B standard cables in a network, the network will run perfectly fine. However, if someone has to cut a cable and re-punch it, you run the chance of punching to the wrong standard. Best practice is to have all cables that are permanently installed (behind walls, through the floor or ceiling, etc) wired to the same standard.

 
 
 
 
 

3. Myth or Fact: The distance between a workstation and a wiring closet can determine how fast the Internet runs on that person's computer.

 
 

This depends. The rule of thumb for Ethernet is that the distance between any two nodes should not be more than 100 meters (328 feet). Node to node may be understood as two items that get external power; patch panels, wall plates, and other components in the network typically don't count as nodes. If you run an Ethernet line exactly 328 feet from your wiring closet to a wall plate, when the user puts a short, 2 foot cable between the wall plate and the computer, they will actually be over the limit.

 
 

What happens if you go over the limit? Most often, users will experience very slow signal or no transmission. Your best bet is to always leave a little slack room between nodes. If you have to run cable beyond 100 meters, your best bet is to use a media converter to change the signal to fiber, then change it back to copper at the drop point.

 
 
 
 
 

4. Myth or Fact: In the wiring closet, Ethernet cables must be kept loose, not neatly tucked away, or else the internal wires could be damaged. This is why so many wiring closets are so messy.

 
 

Actually, this is partially true. The wires within Ethernet cables are twisted together, and this is important for the category rating that ensures the cable can handle the speed of the network. If the cable is bent, rotated, and flexed too much, those twists can come undone, throwing off the delay skew values. 

 

The rule of thumb is that Ethernet cables should never be stapled or tightly wound around something that would put a kink in the cable. Also, if you must make a tight 90 degree turn, you should make a 90 degree turn in the opposite direction nearby so the pressure on the twists is offset.

 

Of course, in your network closet you can easily use cable management equipment combined with angled connectors to keep the cables neatly under control. There's really no excuse for a messy wiring closet!

 
 
 
 
 

5. Myth or Fact: It doesn't matter whether you use solid conductor cables or stranded conductor cables, so long as you use a high enough category rating on the cables.

  

The difference between solid and stranded conductors is negligible, especially in short runs. So long as the category rating is high enough for the speed of your network, either should work.

 

However, that doesn't mean you can use solid and stranded cable interchangeably. Stranded conductor cables have the advantage of being much more flexible and able to take more abuse. For that reason, stranded cable is ideal for making patch cables, which may be moved and flexed as equipment moves. 

 

Solid conductor cables tend to fit better in 110 punches, and over long runs it performs slightly better. The standard suggestion is to use solid conductor in 90% of long cable runs and 10% or less of stranded conductor cable. This makes solid the preferred cable to use in permanent installations such as through the walls of a building between the wiring closet and the drop points.

 
 
 
 
 

6. Myth or Fact: If you want to dramatically improve the speed of your Ethernet network, you should use all shielded, plenum rated cables.

 

Myth! Neither shielding nor plenum rating will dramatically improve the speed of a network, though both shielding and plenum rating have their uses. The shielding on a cable helps to protect it from electromagnetic interference (EMI). In some applications, like radio stations, power stations and factories where high-power equipment may be running, EMI can be a big problem. 

 

In those situations, shielding doesn't merely help, it is essential (and yes, it does dramatically increase the speed in those situations, but only because the speed without shielding would be dramatically slower). In all other situations, shielding doesn't do anything but cost more money, and it may actually hurt a network if the shield isn't properly grounded at both ends.

 

As for plenum rating, this has to do with the material that the cable jacket is made out of. Plenum rated cables are specially designed to self-extinguish if there is a fire, thereby preventing the fire from "jumping floors" or burning through the air ducts where the cables are often run. This has nothing to do with how the cable performs. 

 

In some buildings, such as high-rise offices, schools, and hospitals, the local fire codes requires plenum rated cable because the occupants may not be able to escape as quickly in the event of a fire. But if your fire code doesn’t require this, you're better off seeking standard Ethernet cables.

 
 
 
 

Also, check our text and video tips on modular and networking products. L-com offers a plethora of Ethernet related cables and components, including panel mount couplers, patch panels, switches,  and other adapters.     

How To Protect Your Coax Equipment

July 10, 2014 at 10:00 AM

 


Coaxial lines have a wide range of uses- from video connections to wireless LANs- and are commonly used in both residential and commercial applications. Some of the advantages of coax are that it provides for ease of connection, low noise, and is easy to acquire and install.

 

But in just the blink of an eye, your expensive coax attached equipment or coax connected system could be hit by a powerful lightning strike that has the potential to ruin everything. 

 

That’s why the all-mighty engineering gurus came up with a device called a coax lightning protector

 

We’ve touched on this topic briefly in a previous post (Surge Protectors: Your Best Investment in Protecting Your Wireless Network) but today we will focus specifically on:

 

• Quarter Wave coaxial lightning and surge protectors

• Gas Discharge coaxial lightning and surge protectors

• Coax lightning protectors integrated into coax cable

  

 First, let’s find out- 

 

 

Why coax is vulnerable

 

In a coaxial cable an electrical impulse signal is transmitted along the cable length between the center conductor and the outer conductor. This makes coax an extremely effective conduit for lightning generated pulses. 

  

Therefore, lightning and power surges present a considerable threat to expensive electronic and networking equipment connected to coax cables.

  

 
 
Your options for Coaxial Lightning and Surge Protectors
 
 

Quarter Wave coaxial surge protectors are designed to pass the desired frequency while suppressing lightning surges, much like a signal filter. Lightning strike electrical surges, which operate at low frequencies, are diverted through the protector's short-circuit to the ground. 

  

Here at L-com, we offer HyperLink brand quarter wave suppressors. With a non-gas tube design, multi-strike capability and fast response time they are suitable for a wide range of applications. 

  

The lightning protector's housing also uses a ground lug, which allows for superior grounding. Both connector ports on these suppressors are equally protected, which provides equal protection no matter which way it is installed.

  

On the other hand, Gas Discharge coaxial protectors are a type of lightning arrestor which employs a replaceable gas discharge tube. This component actually contains a small amount of gas. The gas tube dumps extremely high amounts of surge energy directly to the ground of the protector. 

  

A circular brass contact inside the coaxial protector ensures the gas tube is firmly seated and provides a superior contact point for the gas tube. Most coaxial protectors are designed with only a thin pin that the gas tube sits on.

  

L-com’s HyperLink® coaxial lightning and surge arrestors are available for 0-3 GHz operation or 0-6 GHz operation.

 

Here's how it works: 

 

 

 

And your third option for protecting your coax connected equipment is our surge protector integrated coax cables

 

These protectors are high performance low loss 400-series cable assemblies that feature a N-Male connector to a N-Female Bulkhead in-line gas discharge tube lightning protector. Attached directly to the cable, the coaxial lightning protector features wide-band operation up to 5.8 GHz. This saves on insertion loss by having one less connector inline.

 

The cable assemblies feature L-com's CA-400 UV resistant polyethylene jacketed high performance flexible low loss coaxial cable. Attached directly to the cable is L-com's AL6-NF-14-9 5.8 GHz coaxial lightning protector. 

 

These assemblies also feature a replaceable gas tube element and multi-strike capability. Additionally, a ground lug and terminal is attached directly to the lightning protector housing, which provides superior grounding. 

 

If you’re looking for something that is not listed on the L-com website, custom lengths and connectors are also available.

 

Don’t hesitate- protect your valuable coax investment today!

 

 

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