In Australia, there are 3 readily available WiFi frequencies available for public WiFi Networks and long range Point-To-Point (PTP) / Multipoint-To-Point (MPTP) inks. Each has their own advantages and disadvantages. 900mhz900mhz is rarely used in consumer equipment and is normally used for long distance links. It has the best signal penetration (due to its long wave length), but generally offers the least bandwidth. Its often the best choice for long distance links which have trees blocking the beam (ie, it works the best for non-line of sight). Some phones (generally older phones) use this frequency due to its signal penetration benefits. However, whilst very few consumer devices use 900mhz, due to the limited frequencies available, in some areas they can be quite congested (degrading performance). Companies such as ubiquiti offer equipment up to 150+ mbps. In practice however, line of sight connections still generally significantly better performance. Non-Line of Sight Should be considered to be a final resort. 2.4GHZ 2.4Ghz is the most common Wireless Frequency, and is commonplace in almost all consumer equipment, including mobile phones, laptops and Smart TV's. Many wireless devices such as Wireless balun's and phones also share this frequency. Microwave ovens can also introduce intermittent interference. In fact, recently, the Parkes Radio Telescope determined that their own Microwave was a source of intermittant interference when listening to space. The most common standards are 802.11b (11mbps), 802.11g (54mbps) and 802.11n (150+ mbps or higher), and the spectrum is quite limited Due to its prevalence, in dense areas, 2.4GHZ can be highly congested. For long distance links, changing the polarity of the dishes (often done by rotating them 90deg), can help eliminate alot of the interference/noise and improve the link. In a rural environment (with no interference), 2.4GHZ generally offers better performance than 900mhz for Line of sight connections, but generally handles trees worse. 5GHZ5GHZ Wireless is a lessor used, but common wireless frequency. Most WiFi protocols are moving towards 5GHZ due to the larger amount of unique channels available, which allows more networks to operate without interfering. Common WiFi protocols include 802.11a (54mbps), 802.11n (150mbps+) and 802.11ac (1000mbps+). Whilst 5GHZ can often penetrate a few plaster walls, its signal degrades quite quickly in non-line of sight condition. For Line Of Sight connections (or connections with heavy interference) or in WiFi dense areas however, 5GHZ generally offers the best performance . Regulatory requirementsKeep in mind that different countries have different maximum transmit power rates for different frequencies, and some countries may prohibit the usage of, or allow some wireless channels (for 802.11n for instance, Channel 12 and 13 are not permitted US, however, may be used in Australia). When purchasing Wireless gear, always ensure that its legal for use in Australia. Other WiFi frequencies may also be available legally within Australia. We strongly recommend checking local regulations before purchasing devices outside of these 3 frequencies, as they may require a permit to operate (however, generally they offer the benefit of reduced interference on the frequency bands).
