THE NEWS that South Africa’s second fixed-line provider Neotel has been allocated a part of the 800MHz frequency on which to run part of its network raises the question: Why is everyone getting into a state about spectrum allocation?
Simply put, the amount of radio spectrum is limited and it’s the responsibility of SA telecommunications regulator Icasa to ensure that each part of the spectrum is allocated to those companies that need it.
The spectrum covers the ambit of electromagnetic waves – from long wave through to X-rays and gamma rays. But only a small part of that, just above the broadcast spectrum, is suitable for sending data wirelessly.
The problem is that if you have two companies using the same technology, then there’s the potential that the two signals will interfere with each other, like two people talking loudly at the same time. To counteract that, Icasa allocates a subset of the frequency to each player. It’s the potential for interference that necessitates the strict control of wireless providers and the systems they use.
Parts of the radio spectrum aren’t regulated and those are used for the wireless networking you’d find on a laptop or the Bluetooth technology on cellphones. With those the people designing the technology work out ways to ensure that multiple devices and networks don’t interfere with each other too much.
Different wireless technologies broadcast in different parts of the wireless spectrum. Those are set at an international level but usually there are different parts of the spectrum allocated in different countries, mostly for historic reasons. For example, the cellphones we use every day can send and receive at 900MHz and 1800MHz – the two main frequencies we use in SA – as well as at 1900MHz, the frequency they use in the US.