Getting up to speed with 802.11ac
As the demand for wireless bandwidth continues to grow, the standards bodies are working hard to find ways of creating more capacity.
The next standard to come along is 802.11ac. It’s due to be ratified in early 2014, but there are already products on the market which support it, and more will follow in the next few months.
So what does 802.11ac offer? It promises:
- Higher data rates
- Higher capacity
- Lower latency
- More efficient power usage
It does this through both a move to a different part of the spectrum and developing some of the technologies introduced with the current standard 802.11n. These are the key things to look out for:
- A change in frequency – 802.11ac operates only in the 5 GHz band. At the moment this is less busy, so there should be significant benefits
- Wider channels –802.11ac gains its speed by using 80MHz wide channels. In a second phase there will also be the option of 160MHz channels. However this means there will be fewer available channels in the 5 GHz band. The exact number will depend on your country: up to four 80MHz channels in Europe, and up to five in the US.
- Higher modulation and coding – 802.11ac introduces higher order modulation using 256QAM. This increases the number of bits that can be encoded in a single symbol and can provide up to a 33 per cent improvement in bit rates.
- Beamforming – this allows 802.11ac Access Points to deliver a wireless signal straight to a device rather than covering the entire surrounding area. This was also supported in 802.11n, but it’s more efficient in 802.11ac.
- Multi-user MIMO – MIMO enables more than one signal to be sent and received at the same time. 802.11ac will use multi-user MIMO to support simultaneous transmissions to multiple clients, provided they are spatially separated. This maximizes utilisation of the RF band.
- GCMP security protocol – 802.11ac will largely use AES-CCMP but 802.11ac also permits use of GCMP – the Galois/Counter Mode Protocol. Each block is authenticated individually, which means GCMP can encrypt data blocks in parallel instead of in sequence, reducing latency. (If you’d like more information on this, see our blog posted on 31 August.)
So that’s the technology behind 802.11ac. If you would like to read more about this topic please download our White Paper and learn what 802.11ac offers, so you can plan your future WLAN growth with confidence.
Related WLAN Resources
Whitepaper: Implementing 802.11ac - evolution or revolution?
802.11ac Expertise Page