What is WiFi?
WiFi is a technology designed for exchanging electronic data using radio waves over a computer network.
The WiFi trademark and technology licenses are managed by the WiFi Alliance, and only products which complete WiFi Alliance testing may use the official logos.
WiFi enables connections between devices across a wireless local area network (WLAN), direct connections between devices (Wi-Fi Direct), personal area networks (PAN) and even wide area networks (WAN) such as long-distance wireless internet.
WiFi has a theoretical range of about 100 metres across open space and 30m indoors, but in practise this is severely reduced by building materials, particularly metal structures. More recent versions have improved the signals’ range and resistance to interference.
Are WiFi and 802.11 the same thing?
Yes. WiFi is a brand name for the IEEE 802.11 family of standards, agreed by the members of the WiFi Alliance – almost 400 companies – through the Institute for Electrical and Electronics Engineers (IEEE). The earliest WiFi standard in broad use was 802.11b, and the most recent is 802.11ac.
What’s the difference between WiFi, Bluetooth, 4G, LTE and WiMax?
They’re all designed for different purposes, although they do cross over.
Bluetooth is designed for short-range, low power, one-to-one device connections between mobile phones, peripherals such as headsets, and computers.
The terms 4G and LTE describe any ‘fourth generation’ technology for long-distance high-speed data communication beyond 3G mobile broadband, and WiMax is a 4G/LTE standard for up-to-1Gbps fixed wireless broadband services (it uses the IEEE 802.16 standards).
What is in a WiFi network?
Typically, WiFi devices in a network connect to each other and the internet through an Access Point.
In small homes and offices, the AP is usually built into a router, but in large locations there are usually several access points covering different areas, but sharing the same network ID so users can roam around without losing their connection. These APs are connected to the router by physical connections, usually Ethernet cable.
Any device with a Wireless Network Interface Controller (NIC), also known as a wireless adapter, can connect to the AP. These are built into small devices like phones and tablets, but can also be USB dongles and cards which insert into a PC.
Is WiFi secure – WEP, WPA, WPA2?
WiFi has several layers of security, which have been added as the standard has developed, with both physical IDs and encryption.
Every wireless AP has a Service Set ID (SSID) so that users can select it from the many others they may detect in a crowded location. You can turn off transmission of the SSID to hide your network, but it’s quite easy for hackers to ‘sniff’ this from another device’s connection to the AP.
Each device connected to a network has a unique Media Access Control (MAC) address that identifies it, and you can choose to only accept connections from recognised devices. However, it’s easy to ‘spoof’ the MAC address of an approved device and gain access to the network.
There are three encryption standards in WiFi: WEP, WPA and WPA2. Wired Equivalent Privacy (WEP) and WiFi Protected Access (WPA) are no longer considered to be secure, although WPA is effective against casual snooping.
WPA2 is supported by most devices and is backwards-compatible with older WPA devices. It enables users to create memorable passwords out of very long and fairly secure keys, offering up to 256-bit security (although most users won’t use this level).
What is WPS and should I use it?
Introduced in 2007, WiFi Protected Setup (WPS) was designed to allow new devices to connect quickly and securley to a WiFi network AP, usually by pushing a button on both the AP and the new device, or entering an eight-digit PIN.
Unfortunately, it wasn’t long before researchers revealed that made the AP vulnerable and could reveal the WPA keys easily. Newer devices have been secured against this flaw, but it’s recommended that WPS is turned off on older devices, unless you know that it has been updated with a fix.
What radio frequencies does WiFi use?
WiFi uses groups of radio frequencies (bands) near to either 2.4GHz or 5GHz.
The 2.4GHz band is most common, but very busy because it’s shared not only with WiFi users, but also with other wireless devices like cordless home phones, baby monitors and video senders. This congestion can seriously slow down your WiFi connection.
The 5GHz band is used by the more recent 802.11n and 802.11ac versions of WiFi, and is not only far less crowded, but also able to carry more data. High frequencies are, however, more susceptible to interference and more easily blocked by buildings.
What is WiFi B or 802.11b?
Introduced in 2000, 802.11b uses the 2.4GHz band and was the first WiFi standard to be adopted widely. It has a maximum data rate of 11Mbps, although this is shared between all users of the same WiFi network.
In addition, the maximum speed any application can achieve is 5.9Mbps using the TCP protocol, or 7.1Mbps using UDP. If signal quality is an issue, 802.11b will operate Adaptive Rate Selection, increasing error-checking and redundancy in the data stream, but halving the data rate to 5.5.Mbps, then 2Mbps, then 1Mbps.
What is WiFi G or 802.11g?
The WiFi Alliance agreed 802.11g in 2003, also using the 2.4GHz band but with a much more efficient encoding that enables a top speed of 54Mbps, and a practical average of 19Mbps – again, shared between all users.
WiFi G is backwards-compatible with WiFi B, but mixing the two will reduce the top speed that can be achieved by WiFi G devices. Although 802.11g is more robust, if there is interference it will reduce data rates to maintain the connection in a similar way to WiFi B.
What is WiFi N or 802.11n?
The WiFi N standard was agreed in 2009, and brought major improvements including MIMO antennas, frame aggregation, access to the under-used 5GHz band, and longer range of up to 70m indoors and 250m outdoors.
Multiple-Input Multiple-Output (MIMO) antennas uses multiple antennas to deliver independent data streams, making full use of the available bandwidth. Mobile devices tend to have a single antennas and only use the 2.4GHz spectrum, but newer tablets and high-end smartphones are being produced with multiple antennas and access to 5GHz.
In practice, this means speeds range from 7.2Mbps in crowded locations with single-antenna mobile devices using 2.4GHz, to 600Mbps for a PC with a multi-antenna receiver at 5GHz.
What is WiFi AC or 802.11a/c?
WiFi AC is currently in draft form, but it’s sufficiently developed that manufacturers are already releasing 802.11ac access points and receivers which can be updated to the final standard using a downloadable firmware update.
It works at both 2.4GHz and 5GHz, and improvements include wide-bandwidth channels, up to eight data streams, and high-density modulation. WiFi AC routers can also talk to both 802.11n and 802.11ac devices using dedicated data streams, which are targeted on the device to reduce interference and re-use the available frequencies.
It’s backwards-compatible with 802.11b/g/n, but data rates to handheld devices could be more than 400Mbps in practice, and multi-antenna devices such as tablets, PCs and TVs could see 1.73Gbps by combining WiFi N at 2.4GHz and WiFi AC at 5GHz.
What are WiFi Direct and ad-hoc connections?
Rather than communicating through an access point or router, WiFi devices can communicate directly via an ad-hoc connection. WiFi Direct is a formal standard for automating these connections, with a simple push-button or PIN-based system.
It allows one-to-one connections similar to Bluetooth, but with much higher bandwidth, for applications like sending photos from a camera to a PC or printer, or streaming video to a digital TV.
What’s next for WiFi?
WiFi AC is intended to meet needs until 2017, and the WiFi Alliance is working on 802.11ad, or WiGig, which would use 2.4GHz, 5GHz and 60GHz, with a top speed of 7Gbps. The very first products are unlikely to appear before 2014, and they will be compatible with existing WiFi devices.
- Sky’s Wireless Booster blasts WiFi blackspots, free until December 26
- Free open WiFi boon for porn, terrorists and criminals, says Purple WiFi
- German scientists break WiFi speed record
- East Coast announces WiFi upgrade for its rail passengers
- Free WiFi comes to Bradford’s City Park courtesy of Virgin Media Business
- London’s River Thames to flow with WiFi this Spring
- Free WiFi for Manchester in time for Christmas thanks to Arqiva
- Free Unlimited WiFi comes to London’s Square Mile
- Leeds and Bradford to get WiFi thanks to Virgin Media Business
- Free Skype WiFi takes on BT, Sky and O2
A 27 mile stretch of London’s River Thames is to be decked out with free public WiFi by Spring 2013.
This will be complemented by WiFi onboard 24 Thames Clippers London Ferries, which will serve more than 30 million passengers every year with some gratis wireless internet access.
Global Reach, who has helped bring Virgin Media’s London Underground WiFi network online, is responsible for this wireless waterway wonder, which will be winging it’s way sometime in ‘Q1 2013.’
The outdoor wireless access points are the ZoneFlex 7782-N’s made by Ruckus. These are dual-band wireless points (2.4GHz-5GHz, 802.11n) which ought to handle the inevitable congestion when several passengers try to connect at once.
The Thames has become the latest London locale to benefit from public WiFi. As well as Virgin Media’s tube network, The Cloud has piped WiFi across London’s Square Mile and connected major London Overground stations.
January 29, 2013
Free WiFi will be coming to Manchester city centre in time for Christmas thanks to a deal done with Arqiva.
The business service provider has struck a deal with Manchester City Council and Transport for Greater Manchester which will see free WiFi rolling out across the the city centre.
Shoppers will be able to get up to 30 minutes of free WiFi use each day – look out for the ‘_FreeBeeMcr’ WiFi network on your phone or whatever device you’re using.
St. Peter’s Square, Albert Square and Cross Street (pictured) will be the first areas to receive WiFi with further city centre locations, trains and bus routes to follow in 2013.
Early next year, Arqiva plans to open up its network so that mobile networks will be able to offer access to the network to their subscribers, similar to how EE and Vodafone customers will be able to hop on Virgin Media’s WiFi network in London without having to shell out for a daily, weekly or monthly pass.
Image credit: Flickr user Gene Hunt
December 20, 2012
Sky-owned WiFi network The Cloud is now serving City workers in London’s Square Mile with free unlimited WiFi.
The Cloud, which operates a 15,000-strong network of public WiFi hotspots, has signed a deal with the City of London Corporation which sees an area stretching from St. Paul’s Cathedral to the Gherkin supplied with free WiFi.
As well as letting workers connect to the internet on the go on their laptops, tablets and phones, the Cloud WiFi also keeps commuters up to date with tube news from Transport for London as well as Sky News and Sky Sports News.
The Cloud also provides free WiFi at a number of London Overground, First Great Western and Network Rail stations and high street locations including in a number of high street locations including Caffè Nero, EAT, Greggs, PizzaExpress, Pret, WH Smiths and Wagamama.
December 17, 2012
Not content with bringing WiFi to thousands of Londoners, Virgin Media is bringing free public WiFi to the streets of Leeds and Bradford.
To be exact, it’s Virgin Media Business that’s bringing free wireless internet to the Yorkshire cities, in partnership with Global Reach Technology.
Over 1.2 million people in Leeds and Bradford will be able to connect to the free WiFi network from January 2013.
In time for the New Year, free WiFi will arrive in Briggate in Leeds and Bridge Street in Bradford, allowing citizens to tweet in New Year if they wish.
This will be followed by Millennium Square in Leeds and City Park in Bradford will follow in early 2013, with more locations added as rollout increases.
Following successful trials in Bristol, London and Newcastle this summer, Virgin Media Business’ WiFi network ought to provide download speeds up to 90Mbps, three times faster than typical 3G speeds. Of course speeds will depend on the number of people using WiFi at any given time and the ability of your device’s antennas to handle fast speeds.
November 30, 2012
Skype has announced a new public WiFi service called Free Skype WiFi that’s coming soon to a high street near you.
Teaming up with wireless provider Wicoms, Skype will be bringing the service to a number of big-name retail outlets this month.
This will see retailers in the UK and the Republic of Ireland able to kit their shops and branches out with free WiFi for customers to use in store, much in the same way you can access Virgin Media WiFi on the London Underground, Sky’s The Cloud WiFi in Greene King pubs and O2 WiFi in Costa.
Unfortunately there’s no names available yet – we understand that a list will be released soon.
Data from Wicoms shows that 33 per cent of 18-34 year olds browse Amazon, eBay and Google in store, comparing deals and prices on phones as they go. Over 50 per cent of the same survey group said they are more likely to buy something from a store there and then if they were able to get a discount or phone voucher when they entered.
The one edge that high street shopping will always have over online is immediacy – if you see something there and then and you want it, you can buy it, no extra fees for delivery, no 2-3 working days for shipping. But as price outweighs convenience, vouchers is one area where the high street could stage a fightback.
More on Free Skype WiFi as soon as we start hearing about which shops will be piping it through to their punters.
October 2, 2012