Using the 5GHz Band in the UK: OFCOM

5GHz Band in the UK

Operating radio links in the 5GHz Band in the UK: OFCOM

5GHz Band in the UK

Operating in the 5GHz Band in the UK requires some knowledge of regional regulatory requirements.  In the UK, these are governed by OFCOM . In comparison, 2.4GHz is relatively simple – Just pick a channel between 1 and 11 (in some cases  you can include 12 and 13 – although this is not best practice) and keep to no more than 100mW effective radiated power and all is groovy. With 5GHz however your legal limits are defined by which frequency you are operating within and which frequency you need to operate within is defined by your link requirements.

The 5GHz spectrum in the UK runs from 5150MHz (5.15GHz) to 5850MHz (5.85GHz). This is then broken down into 3 different bands (Band A, B and C). Each band has its own maximum allowed effective radiated power output and specific rules as to where it can be used and whether a license is required to operate within it.

This info is contained in the table below

Band Low High Indoor/Outdoor Max Power Level License Requirements
A 5150MHz 5350MHz Indoor 200mW License Free
B 5470MHz 5725MHz Indoor/Outdoor 1000mW (1W) License Free
C 5725MHz 5850MHz Outdoor (FWA) 4000mW (4W) Licensed

 

Band A (Channels 36 – 64)

This is used for Indoor wireless only and does not require a license. It is a 200MHz wide band which allows for 8 x 20MHz channels to coincide without overlap or 4 x 40MHz. The maximum output power is 200mW which is double the allowed output power of 2.4GHz. Now you may be thinking “great – my wireless is going to transmit further!”… Unfortunately, its not quite that simple as the wavelength of 5GHz is roughly half that of 2.4GHz meaning you need to transmit at twice the power to get the same distance. Due to the shorter wavelength, 5GHz also has the worse penetration than 2.4GHz so doesn’t pass through walls and obstacles as well, it does however scatter much better.

I will cover this in more detail in part 2 of the blog, but the bottom line is for indoor use 2.4GHz should be your weapon of choice unless the 2.4GHz spectrum is too crowded or your building is open plan.

Band B (Channels 100 – 140)

Band B is also license free and can be used both inside and outside. It has a higher permitted output power of 1000mW (1W). Being 255MHz wide it allows for 10 x 20MHz channels to coincide without overlap or 5 x 40MHz channels. All hardware operating in Band B must conform to DFS (Dynamic Frequency Selection) standards and DFS must be enabled

Band C (Channels 149 – 161)

If the 1000mW output power limit that Band B offers isn’t enough to suit your needs, then have no fear – Band C is here! Band C can be used with output powers of up to 4000mW (4W). There are some conditions however:

  1. a) Band C can only be used for outdoor wireless
    b) Band C can only be used for fixed wireless access (FWA) points (e.g point to point or point to multipoint links)
    c) A light license is required for operation and must be purchased from Ofcom.
    d) All hardware must conform to DFS (Dynamic Frequency Selection) standards and DFS must be enabled

Band C is 125MHz wide and allows for 4 x 20MHz channels to coincide without overlap or 2 x 40MHz channels.

Licenses For 5GHz in Band C

If you plan to use 5GHz in Band C then you will need to get yourself a license document from Ofcom stating that you have permission to do so.  Now before you start getting worried about costs for spectrum licenses, currently a Band C license costs only £50 a year for up to 50 devices and for each additional device you want to register, it is an extra £1 per year.

Applying for a Band C License

If you’ve decided to apply for your Ofcom License:
You can apply for one by filling in the following form

http://licensing.ofcom.org.uk/binaries/spectrum/low-short-devices/apply-for-a-licence/5.8_app_form.pdf

and sending it to:

Ofcom Contact Centre
Ofcom
Riverside House
Southwark Bridge
London
SE1 9HA

Once authorized you will be provided with a license certificate by Ofcom. Your next step now is to register your hardware by visiting:

https://secure.ofcom.org.uk/opir/

Once registered, you can start using Band C, but only for the devices you have registered.

If you have any other questions about 5GHz Band in the UK, the Ofcom registration process and requirements, then you may find the answers by visiting the FAQ and/or requirements guide at:

http://licensing.ofcom.org.uk/radiocommunication-licences/fixed-wireless-access/faqs

http://stakeholders.ofcom.org.uk/binaries/spectrum/spectrum-policy-area/spectrum-management/research-guidelines-tech-info/interface-requirements/uk_interface_2007.pdf