Wi-Fi 19 / 20 — Geekabit Wi-Fi

Wi-Fi

How to Measure RF Attenuation Through a Wall

Are you having problems with your Wi-Fi? Perhaps you didn’t carry out a Wi-Fi survey prior to designing and installing your network – Or maybe you skipped the design bit altogether!

Dodgy Wi-Fi can sometimes be put down to attenuation, or loss of signal. The main causes of this are the distance the signal is travelling from the transmitter, and objects in the way like walls.

It’s paramount that when you are designing a Wi-Fi network in a walled environment like an office, that you take into account things like walls and their attenuation values. These values can then be used in the design process, indicating where best to place devices and simulate any potential problems that may arise.

Not all walls are the same. Different materials will have a different attenuation value – Basically, some walls will block Wi-Fi signal more than others. Some may be plasterboard, or using plasterboard as a disguise over another material such as brick, concrete, or other materials.

Whatever the material, it’s important to identify what it is and how successfully a signal can get through. Here’s how you can go about measuring the attenuation of a wall.

What you will need:

Something to generate Wi-Fi. This could be the hotspot function on your smartphone, a WLAN Pi in hotspot mode powered by a USB, or a battery pack powered Enterprise grade AP. You need to be able to control the transmitting power and the channel so that your measurements will be consistent.
A device with which you can measure Wi-Fi. This can also be done with a smartphone through AirPort Utility on iPhone or Aruba Utilities on Android. You could also use an AirCheck G2 or an Ekahau Sidekick. The device you choose will need to enable you to scan only the channel your Wi-Fi generating device is on.

What to do:

Identify the wall you are wishing to test.
Place the Wi-Fi generating device at least 4m from the wall, with nothing in-between the device and the wall.
On the measuring device, set the channel to only the scan the channel that your generating device is using.
Point the measuring device towards the generating device on the near side of the wall, making sure that there is a direct line of sight between the devices. Make sure you do not sit or stand between them.
Take a few sets of measurements and make a note of the values. Identify the average for the near side of the wall. You could call this A.
Next, move the measuring device to the other side of the wall, directly in line with where it was before. Again, point the measuring device towards the generating device.
Just like before, take a few sets of measurements and make a note of the values. Identify the average measurement for the far side of the wall. You could call this B.
Work out the wall attenuation: A – B. Make a note of this and document it.

Now you know how much the wall is (or isn’t) blocking the Wi-Fi signal. This can help you identify the best positions for devices like routers and access points when designing and installing your Wi-Fi network.

Thinking this all sounds a bit complicated? Luckily for you, our expert Wi-Fi engineers here at Geekabit are pros at carrying out this sort of investigation. We offer site surveys, Wi-Fi design & planning and Wi-Fi installation.

If you already have a Wi-Fi network set up, but have a sneaking suspicion that a particular wall might be causing you problems then we can also help diagnose any Wi-Fi issues in an already established network.

Get in touch with us today to see how our Wi-Fi experts can help you.

by admin24th October 2020

Wi-Fi Advice

Three types of Wi-Fi wireless network

There are three main types of wireless network – How do you know which wireless network is right for you?

Here we’re going to talk about three wireless networks to help you identify which would work best for your business.

We’ll be looking at centralised deployment, converged deployment and cloud-based deployment to see which one suits different types of applications.

Centralised Deployment

The most common wireless network system is centralised deployment. These lend themselves well to environments where buildings and networks are all in close proximity. This type of deployment brings the wireless network together which helps to facilitate advanced wireless functionality. It also enables easier upgrades. Wi-Fi controllers in these networks are based on-site, installed in a location at the centre of the network.

Converged Deployment

This type of wireless network works well for smaller environments such as an office building. They offer a consistency for both wireless and wired connections due to combining them both onto one network device. This device is an access switch which acts as both a switch as well as a wireless controller.

Cloud-Based Deployment

This deployment is ideal for networks that cover multiple locations. Devices connected on the premises of these different locations are managed by cloud software which via a dashboard, enables full visibility and management of said devices.

Once you’ve identified which network your business needs, you can then go about designing it. A site survey is invaluable at this stage, and enables a theoretical map to show up any potential problems before installation goes ahead.

If you need some assistance with your wireless network at any stage – From Wi-Fi site surveys, wireless network design, Wi-Fi installation or help with a current Wi-Fi network – Please don’t hesitate to get in touch with us today. Our expert Wi-Fi engineers are here to help, and are still working out of our Hampshire and London bases.

by admin21st October 2020

Wi-Fi Site Survey

Why Site Surveys Are a Good Idea

Here’s a little photo of one of our previous clients who was having a bit of trouble with their signal strength… (and no, that’s not a pot of Jaffa Cakes).

You don’t need a site survey to understand why their Wi-Fi wasn’t working particularly well. A thick castle wall, hundreds of years old, is not the best place to plonk a bit of wireless kit – The signal just isn’t going to get through that.

However, there are plenty of reasons why a Wi-Fi site survey is a good idea for your business. If you’re in a very newly built building or have a very open-plan office, then you might be lucky and not need too much thought behind your WLAN.

However, many offices and buildings will need a slightly more detailed review of potential interferences, rather than just relying on intuition. For example, what if a wall you think is just dry-wall actually has brick underneath?

A site survey will enable you to make informed decisions when designing your WLAN – The aim is to collect as much as data as possible.

When we carry out a site survey at a specific location, we are able to ascertain whether signal would be lost or hindered through certain walls, where glass or tiling could have an affect, identifying any appliances or other causes of interference, finding reductions in RF, seeing where any reflections or refractions happen and much more. Things that you might not even think of – Enormous fish tanks for example! A popular addition to many businesses, but not so friendly to Wi-Fi signal.

Our aim is to gather as much information as possible, so that when we design your WLAN we can ensure that by knowing the building materials, RF characteristics and possible inhibitors of Wi-Fi signal in your specific location, we can design the most accurate, successful and reliable WLAN for your business.

If you’re just about to move into a new business space, it’s an ideal time to get in touch so we can carry out a site survey and make sure that the design of your new WLAN will work perfectly. That way everything is already in place and will work well, making your transition to a new office as smooth and problem-free as possible.

However, if you’re already in your office but your having Wi-Fi problems then we can also help with that too. By doing a site survey on how your current infrastructure and devices are working (or not working), we can advise how it can be improved and design a new WLAN for your space that will work more efficiently.

Either way, a site survey is most definitely a good idea.

by admin3rd April 2019

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/

by admin23rd August 2017

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.

by admin17th August 2017

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.

by admin17th July 2017

Uncategorised

Coffee shop cyber-security – how high is the risk?

It’s fair to say that the media has a way of taking an idea and running with it, which can often create hysteria. This week we’ve been reading a lot of stories about internet security in public spaces and have been questioning the findings.

Ipass have just published their 2017 security report and the findings have been interesting. Coffee shops have been flagged up as public networks where hackers can most easily access other people’s data. The findings stated that CEO’s present the greatest security risk to businesses as they are often working remotely and therefore connect to public wi-fi which could pose a risk. Of course, CEO’s are in possession of valuable information and so the risk to a business could be colossal. Interestingly, the report states that many organisations have stepped up their security measures and don’t allow employees to connect to public networks due to concerns about internet safety.

These findings have not only raised questions for businesses but have also raised questions about our everyday safety and how reliable public wi-fi really is. However, there are ways to ensure that you are always secure. VPN’s can help to create a safer connection by encrypting information travelling to and from a device. Using a VPN can inhibit these attacks and keep your information safe so we thoroughly recommend looking into that as an option. The reports are interesting and raise valid points about cyber security. However, it’s always worth bearing in mind that there are ways to reduce your risk. Get in touch to find out more!

Read the full report here:

https://www.ipass.com/wp-content/uploads/2017/05/iPass-2017-Mobile-Security-Report.pdf

by admin23rd May 2017

Uncategorised

Battle of the best connection

This week, our interest in maintaining incredible internet connection has lead us to finding out which countries Wi-Fi is performing best.

And the results have been interesting…

Rotten Wi-Fi’s latest findings show that the UK is surprisingly quite far behind other countries in terms of interest speed. Public Wi-Fi has become a pretty essential part of everyday life for most of us and the demand has certainly increased in recent years. Interestingly the UK falls behind countries such as Lithuania and Switzerland when comparing the average download speed.

Although we do come in behind Lithuania, Singapore, Denmark and Switzerland in terms of internet speed, we are placed ahead of the USA and Germany. In fact, the USA and Germany haven’t been doing so well in recent years and their internet speed hasn’t made the top 20 until this year. The latest findings show that countries such as Latvia, Hungary and Estonia are still ahead of Germany and the USA in terms of download speed.

Lithuania tops the charts with the fastest public Wi-Fi, followed closely by Denmark. Fast and effective public Wi-Fi is hugely important in the modern day and we’ll be interested to see if the UK can develop their Wi-Fi speed to keep up with the demand in the coming years.
Data source: www.rottenwifi.com; November 2016

Image Credit: Alto Digital

by admin15th May 2017

Uncategorised

Dreaded Dead Spots

We’ve all been there.

You’ve set out to do some work in a coffee shop and after ordering your coffee and finding the perfect corner to settle down in you realise the Wi-Fi doesn’t work there. ‘Typical’ you think as you pace around with your device in hand trying to find a connection.

This week we’re trying to discover what it means to have a Wi-Fi dead spot and how to avoid these cursed spaces.

There can be so many reasons for these dead spots but the main ones are building interferences ie – thick walls or awkwardly placed Wi-Fi access points that can’t reach certain areas. With that in mind, it can be quite easy to fix these mysterious dead spots which makes it all the more frustrating when you come across one.

If you find a dead spot in your home or business space the first thing you can do to try and close up these dead spots is to re-position your access point. Often central locations suit access points best, where they can get away from thick walls or fire exits which can all interfere with signal.

That brings us to our second suggestion – removing obstructions and ensuring that your access point is free of any interference. Often clients don’t realise how easy it can be to eliminate these obstructions from the area. If you identify anything near the access point that you think could be causing problems then remove it and see if the dead spot remains – in most cases dead spots require a trial and error approach. Other electronic devices and thick metals can be a source of interference that often go overlooked but it’s worth getting to the bottom of the issue and ensuring that you try removing as many obstructions as possible to see if that affects the dead spot.
If you need more advice on how to avoid these frustrating dead spots then don’t hesitate to get in touch. It’s always helpful to get an expert opinion if the problem persists.

by admin10th May 2017

Uncategorised

Wearables wreaking havoc

This week at Geekabit we’re talking about wearables.

Wearables are the newest fitness craze and it seems that social media is full of people uploading their data. Everyone is tracking their heartrate and their steps these days and we’re not complaining. Wearables are a great advance in technology that can benefit health so we’re all for the latest craze.

However, we are not for the congestion that has inevitably increased since wearables became a ‘thing’. Wearables are often Wi-Fi enabled, however ones that aren’t can really cause problems since the Bluetooth that they operate off of uses the same 2.4Ghz frequency as most Wi-Fi services.

The initial cause of disruption is just the fact that people have gone from having one device to having two or three which puts pressure on the network. Not only that but as we previously mentioned, there is the danger that your 2.4Ghz band will get congested by wearables operating using Bluetooth. As people become more and more attached to their wearables and start to take their data seriously, it is becoming hugely important to have a Wi-Fi service that can handle the demand.

Luckily we know a few tricks that can help solve these issues and make sure that your customers don’t get frustrated by the congested W-Fi. An easy way to solve the congestion is ensure that fewer devices are operating on the network, as every device is using up bandwidth. It might pay to get a separate network for personal use or for employees if your network is based in a place that is used by both customers and employees. As always with these things, a survey is a great idea. A Wi-Fi survey will tell you exactly what is going on with your network and how much it can take vs what pressure is being put on it. This is hugely helpful to any business experiencing Wi-Fi problems which have potentially come about by increased pressure on the network from wearables.

If you think that your network is being affected by wearables then don’t hesitate to contact us to gain some useful advice on how to solve these issues.

by admin27th April 2017