What are 2.4 GHz and 5 GHz?
2.4 GHz and 5 GHz are two different unlicensed wireless frequencies. 802.11g devices, which tend to be the older devices, use the 2.4 GHz frequency whilst 802.11n devices, which include newer devices, use 5 GHz frequency. 2.4 GHz provides much wider coverage than 5 GHz (since waves attenuate faster at higher frequencies).
The problem with 2.4 GHz
2.4 GHz sounds ideal as it provides greater coverage but there are problems. The main one is that there are only three non-overlapping channels (1, 6 and 11). Hotel WiFi installations tend to use these three channels. However there are two main problems:
- It can be difficult to avoid interference when designing a network if you only have three non overlapping channels to use. It is easy to create interference within a network if you are not careful (although the better vendors produce products which mitigate against this)
- Unlicensed spectrum is, by its nature, available to all and is used my microwaves, cordless phones and other devices. This can obviously cause interference with your WiFi network.
So is 5 GHz the answer?
5 GHz does solve the issues of non overlapping channels – there are 23 non-overlapping channels which is enough for most situations but it does have a couple of problems:
- Coverage is not as extensive with 5 GHz Access Points (APs)
- Older devices do not work with the 5 GHz frequency
What about dual band APs?
AP manufacturers have recognised that both 2.4 GHz and 5 GHz APs have advantages and disadvantages and launched APs with dual radios so that one can broadcast in 2.4 GHz whilst the other broadcasts in 5 GHz. Ostensibly this would seem to be the best of both worlds and something which hotels should adopt.
However, there is one slight flaw with this approach which is that some devices will connect using there 5 GHz in preference to 2.4 GHz even when the 5 GHz signal is significantly weaker. This can give rise to a very weak effective signal being utilised which can cause problems. However, some AP manufacturers have recognised this and brought in “band steering” to try and mitigate this problem.
If you or your team would like some technical advice on designing your WiFi network then please contact Veridicum.