Wifi explained


The UK mobile phone service is based on a set of International standards.

The most current 3G standards allow us to have voice, text and data communications to a mobile phone whilst on the move.

In addition, most mobiles, Tablets, PCs and laptops also have a Wifi capability.


So what is Wifi?

Wifi provides a cheap method of using signals(frequencies) to wirelessly linking devices(like laptop and phones) to a transmitter, which in turn is linked to the Internet.

The transmitter creates a small(typically 20-100 metres), fixed geographical footprint(or HotSpot) in which your mobile/laptop can recognise the signal and gain access to that transmitter’s Internet connection.

The transmitter never moves, so if you(device) move outside of the footprint, any connection you have will be lost.

Wifi is also a standard( named 802.11) from another organisation called the IEEE working at the 2.4, 3.6 and 5GHz frequency bands.

Who runs Wifi services?

There are 3 distinct types of service in the UK.

  1. If  you have broadband hub at home/work it will typically come with Wifi access, which you can link to.
  2. The UK has several Wifi Service Providers including the likes of BT OpenZone and The Cloud
  3. Finally individual organisations like say hotels, Internet cafes etc. all provide a service.

On my iPhone simply touch Setting-Wifi and the phone lists the Wifi networks currently in range.

It will tell you the strength of the signal and if they are secure or not.

Wifi Security

My broadband hub from BT has Wifi access. Each hub has a unique  SSID(Service Set Identifier) which(when you attempt to connection) you input to create a secure connection to the Internet.

But what about in a hotel or cafe or in the park?

Your  mobile/tablet can use it’s Wifi search facility to detect Wireless networks(hotspots).

It will tell you the which Wifi networks it has found, the signal strength and if they are secure or unsecure.

Your Wifi search might find a local private broadband hub, which will require a SSID for access. No SSID no access.

Your Wifi search might find the local Wifi Service Provider/s like  BT Openzone, The Cloud, T-Mobile and Orange, who can offer access minutes as part of an Internet access tariff. For these you will need and account and password and in return you get a secure connection.

Finally your search may find Unsecure Wifi networks(Free Internet Access).

Trouble is, if you can get on for free so can everyone else, leaving your device open to hacking, or the interception of your personal data as your transmit. Often described as a Man in the Middle(MITM) attack, users appear to be logged directly to the Internet when in fact their data is routed through an intermediate device which stores all the details.


Wifi access can be

  1. free,
  2. part of a mobile monthly call plan
  3. something you buy separately from a Wifi Service Provider.

Examples of Wifi Service Provider costs are :

  • 90 minutes costs £5.99 to be used in 24 hours
  • 4000 minutes costs £40 to be used in a 30 day period.

What Speed will I get?

The IEEE standards provide for speeds up to 54Mbps, however the available Speed is only as fast as the connection from the Wifi router/hub to the Internet.

The likelihood is that Wifi Service Providers offer faster Internet Speeds than a cafe that simply connects their Wifi router/hub to their broadband connection.

However, Wifi is a shared resource. All the devices that are linked to a Wifi router/hub compete for the available Internet bandwidth.

The Future

As stated, many mobile users, will switch to Wifi services(if available) on their mobile when they require large amounts of Internet traffic. It is simply a cost saving exercise.

The fact that Wifi has a fixed range(Hotspot), and a simple structure means equipment costs are low.

However, the next step could be Wifi Roaming according to the Wifi Alliance www.wifi.org.

In essence, and assuming the Hotspots overlap users could move between them……like a mobile network……………

Then what is WiMax?

….but I saw a phone advertised with Wimax connectivity. What is Wimax?

WiMax is IEEE 802.16 standard

WiMax is not a replacement for Wifi but  a ‘last mile technology’, in effect a way of getting large amounts of data to local points in a town of city.

WiMax is a licensed resource. Each user has a licence to access a specific amount of Internet bandwidth with a given Quality of Service.

WiMax operates at much higher speeds than Wifi  in either Line-of-sight or Non-line-of-sight. The former can operator over 120km, the later 35kms depending on equipment costs.

Wimax typically uses a Tower(transmitter) and obviously receivers at local points around the transmitter, each with their own specific customer profile.

WiMax networks are expensive to construct and operate when compared to Wifi.

Mobile Phone manufacturers may offer WiMax in their handsets, however the tariff plan would initially be very expensive.

Useful Websites has the links to the ITU and IEEE.


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