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WLAN vs Ethernet LAN

The difference between WLAN and Ethernet LAN

We thought it would be very useful to have a comparison between WLAN (Wireless LAN) and Wired LAN – The following post describes the difference between WLAN and Ethernet LAN.

In the figure-1 below, you will see the wlan or wireless LAN network. It operates on radio frequency 2.4 GHz or 5.8 GHz or both as per IEEE 802.11 specifications. There are various WLAN versions viz. 802.11a, 11b, 11g, 11n, 11ac and 11ad etc. The latest WLAN versions incorporate multiple antenna based MIMO techniques to provide support for higher data rates.

wlan network

In figure-2 below, you can see the ethernet lan network. You might like to also look up Ethernet types such as ethernet, fast ethernet and gigabit ethernet.

Ethernet LAN network

 

In summary, the core differences between wlan and ethernet LAN types are as follows:

WLAN Ethernet LAN
The WLAN devices are based on IEEE 802.11 family of standards. The Ethernet LAN devices are based on IEEE 802.3 standards.
WLAN devices use high energy radio frequency waves to transmit the data. Ethernet LAN devices use electric signals to transmit the data.
Radio frequency waves travel in the space. Hence a physical connection is not needed between the devices which are connected to the WLANs. Electric signals flow over the cables. Hence wired connection is needed between devices which are connected to the Ethernet LANs.
WLAN uses half duplex mechanism for communication. Ethernet supports full duplex mechanism for communication when a switch connects using a single device rather than hub.
WLANs suffer from interference of various types during travel from source to the destination. LANs suffer less interference as electric signals travel using cables.
WLANs use CSMA/CA to avoid collisions in the network. Ethernet LANs use CSMA/CD to detect collisions in the network.

For more info: http://www.rfwireless-world.com/Terminology/WLAN-vs-Ethernet-LAN.html

 

Contact us!

London 0203 322 2443 | Cardiff 02920 676 712 | Hampshire 01962 657 390 | Email [email protected]

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Uncategorised
Wi-Fi Frequencies: An Overview

There are actually more Wi-Fi frequencies than you may think, and with all of the current and future Wi-Fi frequencies and technologies out there, things can get confusing. This blog will take a a high-level look at what’s out there and what’s coming up.

The Well-Known Frequencies — There are two dominant Wi-Fi frequencies used by 802.11a/b/g/n systems; 2.4 GHz and 5 GHz. Almost all modern Wi-Fi devices are made to operate in one or both of these frequencies.

Public Safety — The same basic OFDM technology used by 802.11a in 5 GHz is also used in a 4.9 GHz public safety band. This band is 50 MHz wide, is only available in some regulatory domains and requires a license. This band has specific, limited purposes, so you don’t see a lot of commercial interest or attention here.

802.11y — The FCC also opened up 50 MHz of bandwidth in a 3.6 GHz licensed band. OFDM is also used here. In the US, this band usage is not limited to certain technologies so the band will be shared, but does require a license. It seems that there aren’t many benefits to this frequency band, and the interference avoidance requirements represent a moderate R&D requirement without much ROI.

VHT <6 ghz=”” 802=”” 11ac=”” u=””> —  You may have heard about this PHY spec in development. It builds on 802.11n MIMO technology in 5 GHz and seeks to expand on the HT PHY with a few developments that are a natural next step. 802.11n gave us 40 MHz bonded channels. 802.11ac will give us 80 MHz channels and, likely, 160 MHz channels. 80 MHz bandwidth will get us past the gigabit rate threshold. MIMO will also be expanded to 8×8, but since client devices aren’t adopting that type of power hungry radio anytime in the near future (or ever), 8×8 will be used for MU-MIMO. MU-MIMO allows an AP to transmit simultaneous downlink frames to multiple users (MUs).

VHT 60 GHz (802.11ad) — This PHY opens up a fresh use case for Wi-Fi in the form of very high throughput at short range. At the 60 GHz frequency range, there are a lot of challenges getting the kind of range that would be useful to enterprises. We’ll see short-range, high bandwidth applications, but I’m still failing to see the exciting benefits that have been touted in the press.

White-Fi (802.11af) — There has also been some exciting buzz in the past several months about TV whitespace frequencies between 50 and 600 MHz. The benefits and limitations of this band are discussed in a number of good articles out there. Contiguous bandwidth is in short supply which is a big issue with this frequency, so we see a handful of 6 MHz-wide channels which will yield lower transmission rates than 802.11a/g. The merits of a low frequency are fairly well known; that is, despite the throughput-deficient bandwidth, the range/coverage is advantageous. The evident winner with this technology are rural broadband applications, where coverage is more important than bandwidth and high user density.

Least and last — 900 MHz. 900 MHz was a popular pre-802.11-Wi-Fi frequency way back in the 1990’s. It often gets lumped in with Wi-Fi frequencies because it is an unlicensed ISM band. You’ll still see some legacy technologies working their stuff there, and you might see a few modern, proprietary ones as well. This is a semi-popular broadband frequency with decent range and limited throughput. Many vendors use proprietary PtP and PtMP solutions here for wireless distribution, but they are not defined by 802.11, and they are not designed for client access. Shame on them.

Frequency Recap:

  • 50-600 MHz TV Whitespace — Good range, low capacity.
  • 900 MHz — Proprietary PtP and PtMP. Decent range, slow rates.
  • 2.4 GHz — Well-known and used.
  • 3.6 GHz — Little-used, licensed band.
  • 4.9 GHz — Licensed public safety band.
  • 5 GHz — Well-known and used, the future of Wi-Fi.
  • 60 GHz — Short range, very high throughput.

Contact us!

London 0203 322 2443 | Cardiff 02920 676 712 | Hampshire 01962 657 390 |  [email protected]

 

https://www.cwnp.com/wi-fi-frequencies-an-overview/

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Technology Wi-Fi Advice
Selecting The Best Antenna

 The following post talks about the importance of selecting the best antenna and understanding coverage patterns.

In any RF system, the antenna is the radiating element. RF waves are to be propagated through free space, and it is this component that causes this to happen. The antenna device also receives the RF signals from other transmitters. Available in various forms, the antenna results in varied radiation patterns and, therefore, various coverage patterns given the same RF power input. The antennas design impacts the reception of RF signals, in addition to varied radiating patterns.

Key factors when selecting an antenna are the gain of the antenna and the radiating pattern, as well as the frequency range for which the antenna is designed. Antennas should be either 2.4 GHz or 5 GHz antennas in most AP or bridge implementations today. Once you have identified the appropriate frequency band, the appropriate gain and radiating pattern must be selected.

Today, antenna gain is usually listed as dBi and is measured in decibels. This metric is achieved by comparing the antenna’s gain in the intended radiation direction against that of a theoretical isotropic radiator. The isotropic radiator is a theoretical antenna, radiating energy equally in all directions out of the antenna. Whilst it is considered spherical, no such antenna actually exists. For example, the common antenna included with a consumer-grade wireless AP or router is a 2-3 dBi antenna. This simply means that the antenna has 2-3 dB gain in the direction of intended propagation.

A higher gain antenna (for example, 11 dBi as opposed to 2.14 dBi) will radiate a receivable signal further in the intended direction in free space. Of course, indoors there will be reflections and other RF behaviours, so the signal may not radiate as far at acceptable signal levels as it would in free space, but it would still radiate farther than a lower gain antenna.

Now, the final part to consider when selecting an antenna is the radiation pattern or simply, the antenna pattern. Antenna charts are the most frequent mode of communication of antenna patterns. The horizontal and vertical radiation patterns of the antenna are shown in the charts. 

In the elevation charts, the vertical pattern is shown, and the Azimuth chart shows the horizontal pattern. 

Helpful tip! Remember that the elevation chart shows the radiation pattern of antennas as if you are looking at it from the side. The Azimuth chart shows it as if you are looking down on the top of the antenna (assuming the antenna is vertically upright).

Elevation = side view

Azimuth = top view

The following images show each chart type:

 

Once you’ve got the hang of this information, you can use it to easily select the appropriate antenna for you and understand the different coverage patterns you can expect from them.

 

London 0203 322 2443 | Cardiff 02920 676 712 | Hampshire 01962 657 390 | [email protected]

 

https://www.cwnp.com/selecting-best-antenna/

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Technology Wi-Fi Advice
Calculating RF Wavelengths

Calculating RF Wavelength

Why would you need to calculate RF wavelengths I hear you ask? Well, an antenna needs to best receive the intended frequencies, thus the length of RF waves impacts decisions being made during the design process. This means you need to understand the wavelength of the RF waves being generated in a given frequency.

There are 2 basic formulas you can use to calculate RF wavelength. One is used for feet and the other for metres.

The following post will provide the formulas you need, plus an Excel spreadsheet for calculating the wavelengths for each 20 MHz channel centre frequency in the 2.4 GHz and 5 GHz bands.

802.11 channels work on a centre frequency. In the below spreadsheet, you will find the centre frequencies for each 20 MHz channel in 2.4 GHz and 5 GHz.

Wavelength Calculator

To calculate the wavelength in feet, the common formula is:

wavelength = 984 / frequency in MHz

The common formula to calculate the wavelength in metres is:

wavelength = 300 / frequency in MHz

 

So what are you waiting for? Get calculating!

Alternatively, you could give us a ring here at Geekabit – We are the Wi-Fi Expert afterall! With offices in Hampshire, London and Cardiff you could just get in touch with us and avoid the potential mathematical headache by letting us sort it out for you.

London Office: 0203 322 2443 /  [email protected]

Cardiff Office:  02920 676712 /  [email protected]

Winchester Office: 01962 657 390 /  [email protected]

https://www.cwnp.com/calculating_rf_wavelengths/

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Client Stories
Customer focus: Southern Storage

The Issue
As a warehouse and storage facility, it’s necessary for the team to be able to use their barcode scanning guns to identify the location and correct picking of items, constantly throughout the work day.

They found that their existing Wi-Fi system was not providing coverage in all the aisles and racks at many points in their warehouse, meaning staff had to return to a central area or corridor to check they had picked the right item, wasting time and creating potential mistakes.

With the delivery of new barcode scanners it was also necessary to ensure that the network would work to the best possible speeds.

What We Did
Having reviewed the existing installation, we found that access points broadcasting the Wi-Fi channels were incorrectly placed, often sending the main strength of the signal upwards into the roof as opposed to down to the working areas, and nowhere near the corridors.

The network was a mix of various home quality Wi-Fi extenders and domestic access points, with overlapping channels on a variety of frequencies that caused interference and packet loss constantly.

We replaced the existing access points with outside quality (warehouses are cold!) Ubiquiti Uni-Fi AP’s, and arranged the channels to ensure no interference and better utilisation of the free frequencies available.

These were installed correctly to ensure full coverage in all areas of the warehouse, and the power set correctly to ensure the barcode scanners successfully move between the AP’s seamlessly.

Take a look at what they do at Southern Storage https://southern-storage.co.uk/

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Technology Wi-Fi Advice
WiFi Faces Technical Challenges

The emerging wireless standard promises better WiFi but the promise introduces significant complexity.

IEEE 802.11 standards (g, a, n, ac) delivered WiFi performance improvements out of the box. They focused on progressively increasing the data rate over the wireless link. All that was needed to take advantage of any new standard, was a radio chipset that incorporated the new radio and MAC enhancements.

The situation is different for the upcoming 802.11ax standard. The focus of 802.11ax is not on increasing the data rate but on improving the overall wireless network performance. This introduces significant new radio and MAC enhancements such as OFDMA and BSS colouring.

Ranking high among the issues is a transmission-scheduling mechanism. The downlink transmission scheduling in WiFi has been a simple FIFO (First In First Out) system. 802.11e introduced a small variation regarding the maintenance of multiple transmission queues for different priority classes.

However, 802.11ax introduces significant complexity in wireless transmission scheduling due to its OFDMA and MU-MIMO enhancements.

  •  With MU-MIMO, there is now an option to transmit a single wireless frame to a single client or concurrently transmit different wireless frames to multiple clients using multi-user beamforming.
  • With OFDMA, there is now an option to transmit a single wireless frame to single client using traditional OFDM or concurrently transmit different wireless frames to multiple clients using subsets of channel width.
  • 802.11ax introduces multi-user transmission in uplink direction too. The AP needs to schedule multiple clients for concurrent uplink transmissions according to their requirements.

These methods need to take into account service requirements of traffic flows, radio conditions on the channel, client capabilities and client state feedbacks. It is no easy feat to come up with scheduling mechanisms that will work in most practical scenarios with relative ease of configuration and fine tuning.

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Technology
Children and Technology: how young is too young?

The generation gap is getting bigger and bigger the more technology advances. We see it every day with children, yes CHILDREN have better phones than you do. How often do you see it in the work place or a social setting where everyone in on their phones and not talking?. Well it’s worse for the children of today. Gone are the days where you would go out, climb and tree and hurt yourself!

Studies are showing how big of a role social media and technology play a part in a Childs life today. The average age for getting a smart phone is currently 10.3. Children use their phones overwhelmingly to text and 31% of parents surveyed said their kids have texted them even when they’re in the same house together.

There is of course a useful safety feature on a smart phone of being able to use the GPS to track your child. Although this doesn’t not sound like a fun part of growing up as that is the last thing you would want being a teenager, it certainly has a time and a place. While not many parents have embraced the ability to use Smartphones’ GPS capabilities to track down their kids, the number who has used this function doubled from 7% in 2012 to 15% in 2016.

Phones have risen on the list of devices kids look to for entertainment on car trips and remain second only to iPads and tablets as the engagement option of choice for the road.

  • Tablets have taken off for this purpose, increasing in usage from 26% to 55%.
  • Phones come in at 45%, up from 39% in 2012, and DVDs have fallen to third place in the car with 35% reporting usage today, versus 48% in 2012.
  • The once popular Nintendo DS now dropped to a distant fourth choice at 24%, down from 40% four years ago.

Parents’ restrictions (texting, social media platforms, apps, timing) on their kids’ phones increased from 14% to 34% since our last survey. Proving to be most common form of punishment for todays technological geeks. Especially as 50% of children will have social media account by the age of 12.

  • Social media consumes kids today as well, as most score their first social media accounts at an average age of 11.4 years old. The largest percentage of kids – 39% – got their first account between ages 10 and 12, but another 11% got a social media account when they were younger than 10.
  • Facebook and Instagram represent the most-used social platforms among kids, with 77% using each. But Twitter continues to climb with 49% of kids, and a newer entry, Snapchat, with 47%. No other social media platforms have a significant presence on kids’ radar.

What are your thought on this topic? Do your children have smartphones? How much do you monitor their use and what they are looking at? Let us know.

by admin
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Technology Wi-Fi Advice
Do you know the difference between mbps and mb?

Data and download speeds are all that we barter for when it comes using the internet nowadays. How much data you have is all the phone companies have left to reel you in with on a new offer. Lets break it all down and look at what the differences are.

A bit is the fundamental unit of information that we use in our computing and also in communications. The word ‘binary digit’ is shortened to form the word ‘bit’.  Therefore, we use bits in all our binary digit computations. The computation and communication here mean the digitals ones.

A byte is the unit of information that is used in digital fields and is equals eight bits. We generally address the memory spaces in terms of bytes and it forms the smallest addressable unit of memory space that is been used in computer related technologies. It is referred as ‘B’ in the digital electronics and we should note that it forms the different notion from that of a bit. So an eight-bit can also be called as a byte or simply with ‘B’.

Notions for Bits and Bytes:
We shall write the above-mentioned notions here, to understand it better.

1 bit = is denoted as ‘b’.
For example, it can be written as 1 b.
It’s bit length = 1.
1 Byte = 8 bits is denoted as ‘B’.
It’s bit length = 8.

The capitalisation of alphabets means a lot in these notions. A bit is simply written as ‘b’ whereas a byte is written as ‘B’. As already noted, what they are and what values they can hold. The letter ‘m’ here means Mega. The value 103 is noted simply as Mega so that we can use it in our digital computations with better understandings. When we find a notion as ‘mb’, it means megabits and ‘MB’ means Mega Bytes. So noting the capitalisation of the betters can mean a lot.

The abbreviation ‘mbps’ means megabits per second and it is always used to denote the speed of transmissions. You might have heard it when you opted for a broadband connection. This is what you are sold your broadband on and what you are sold and what you get are two very different things. You can always check the download and upload speeds you are getting online.

Hopefully this will arm you with the information to help you make better decisions in understanding the differences between mbps and mb.

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Client Stories
More Ubiquiti Wi-Fi Installations

Here at Geekabit, we have fallen in love. A love that has lasted at least a good year, and one that gets deeper with every experience.

We’ve fallen in love with Ubiquiti Networks, and their ever-evolving selection of Wi-Fi related goodies, which we use for our client installations and temporary event Wi-Fi work on a weekly basis. And it’s a true love.

For manufacturing, warehousing, education and large residential home projects, we’ve managed to cut down our installation and configuration times, leading to less client down-time and an overall happier experience for our installation team and end user experience.

A few weeks ago, sat in an outside bar/club on the banks of the River Rhine in Berlin, one of our team looked up to the roof, and amongst the twinkling lights, was the familiar blue hue of our new love. We’ve seen them in France, in the most unlikely places across Africa, and even North Yorkshire.

As our business has expanded, working predominantly from London and Cardiff, we’ve seen a huge surge in demand for Ubiquiti devices, and can see this only continuing. There’s a trend throughout almost every market to look for better quality and better prices, people have begun to recognise that good doesn’t always mean expensive.

And as we all know, love, like Wi-Fi needs a good experience. It shouldn’t have to be an expensive one.

xx

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Uncategorised
Wi-Fi Frequencies: An Overview

With all of the current and future Wi-Fi frequencies and technologies are really getting confusing, with that in mind theres actually more than you realise. So let’s take a look at what’s out there and what’s coming up, as well as trying to make it as simple as we can.

There are two common well known dominant Wi-Fi frequencies used by 802.11a/b/g/n systems, 2.4 GHz and 5 GHz. Almost all modern Wi-Fi devices are made to operate in one or both of these frequencies. These frequencies now dominate most of our homes.

The same basic OFDM technology used by 802.11a in 5 GHz is also used in a 4.9 GHz public safety band. This band is 50 MHz wide it requires a license and is only available in some regulatory domains. There are specific and limited purposes for this band so you won’t see a lot of commercial interest or attention here.

The FCC also opened up 50 MHz of bandwidth in a 3.6 GHz licensed band. OFDM is used here as well. In the US this band requires a license but usage is not limited to certain technologies, so the band will be shared.  There aren’t many benefits to this frequency band and the interference avoidance requirements represent a moderate R&D requirement without much ROI.

You’ve most likely heard about this PHY spec in development. It builds on 802.11n MIMO technology in 5 GHz and seeks to expand on the HT PHY with a few developments that are a natural next step. 802.11n gave us 40 MHz bonded channels. 802.11ac will give us 80 MHz channels and, likely, 160 MHz channels.. 80 MHz bandwidth will get us past the gigabit rate threshold. MIMO will also be expanded to 8×8, but since client devices aren’t adopting that type of power hungry radio anytime in the near future (or ever), 8×8 will be used for MU-MIMO. MU-MIMO allows an AP to transmit simultaneous downlink frames to multiple users (MUs).

VHT 60 GHz (802.11ad) — This PHY opens up a fresh use case for Wi-Fi in the form of very high throughput at short range. There are a lot of challenges getting the kind of range that would be useful to enterprises. We’ll see short-range, high bandwidth applications, but there are still failings to see the exciting benefits that have been touted in the press.

White-Fi (802.11af) — The TV whitespace frequencies between 50 and 600 MHz have also created some exciting buzz in the past several months. There are many articles out there discussing the limitations and benefits of this band. The main issue with this frequency is that contiguous bandwidth is in short supply, so we see a handful of 6 MHz-wide channels, which will yield lower transmission rates than 802.11a/g. The merits of a low frequency are fairly well known; that is, despite the throughput-deficient bandwidth, the range and coverage is advantageous. Rural broadband applications are the evident winner with this technology where coverage is more important than bandwidth and high user density.

It is also worth mentioning 900 MHz. Back in the 1990s, 900 MHz was a popular pre-802.11-Wi-Fi frequency. It is an unlicensed ISM band. This is a semi-popular broadband frequency with decent range and limited throughput. Many vendors use proprietary PtP and PtMP solutions here for wireless distribution, but they are not defined by 802.11 and they are not designed for client access.

Wi-FI frequencies in brief:

  • 50-600 MHz TV Whitespace — Good range, low capacity.
  • 900 MHz — Proprietary PtP and PtMP. Decent range, slow rates.
  • 2.4 GHz — Well-known and used.
  • 3.6 GHz — Little-used, licensed band.
  • 4.9 GHz — Licensed public safety band.
  • 5 GHz — Well-known and used, the future of Wi-Fi.
  • 60 GHz — Short range, very high throughput.
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