Radio is a useful method of delivery for community broadband networks. Advantages include how easy it can be to install as well as the cost being lower than some alternatives.
All the hardware available that could be employed in community networks use microwave frequencies. The exact frequency bands and equipment will depend on a number of factors including distance, bandwidth required, the type of terrain to be covered and the expected level of service.
Microwave radio requires clear "Line-of-Sight" from one end to the other. Any obstacles in the way including trees and foliage will hinder the signal. This means that you need to consider the increased growth of foliage in the summer months if installing a network during the winter.
There is a wealth of products available that can be employed in your community's network. These can be split into 3 main categories:
Licensed Radio is generally more expensive and uses more specialist equipment. This means that most communities will probably require assistance with the installation of this type of radio Link. However, the advantages are that you can achieve relatively large bandwidths over long distances and provide a guaranteed level of service. You may wish to consider this type of link for backhaul purposes.
Licensed wireless links typically come in 16 to 155Mbps capacities and are generally used for point to point links between sites. Telecom companies use these links, and so can you. Typical costs for a 155Mbps link are £12k for the equipment – and negligible ongoing costs! An antenna and indoor unit are located at each site following a short planning stage to make sure the link will work. Antenna are mounted on poles or short masts, whatever suits your site. Indoor equipment come with an Ethernet port to let you link direct into your local network. Ongoing costs comprise a small license fee to the Communications Regulator and any maintenance – but these are super reliable, so costs are low.
Lightly Licensed Radio generally uses a portion of spectrum allocated by the regulator at 5.8 or 5.4GHz. For a small registration fee you can use these frequencies to provide outdoor radio links. Maximum transmitter power allowed is higher at 5.8GHz, so distances available are longer, but there are fewer channels available.
Unlicensed Radio generally uses a portion of spectrum at 2.4GHz that has been deregulated and can be used by anyone provided maximum power limits are adhered to. This is the frequency band used by WiFi devices.
Licensed Radio is generally a Point to Point regime, where an "A-End" and "B-End" are specified in the license. Lightly Licensed and Unlicensed Radios are available or can be configured either as Point to Point or Point to Multipoint systems. Point to Multipoint is particularly useful in a community scenario where you may have a single location that has clear Line-of-Sight to all or many of the properties in your community.
Lightly licensed links offer tremendous value for money and can be used for point to point links or for distributing from a central point to multiple other sites. Links typically come in capacity from 10 to 34Mbps and equipment typically costs from £500 per site end. These links offer a huge range of benefits and benefit from high capacity and lower costs. Ideally suited for links up to around 15km, these, links can be installed on roof top or side of a building and connect directly into your internal network. A minimal fee is paid to the Regulator to operate these links.
Unlicensed Radio can also be set up as a Mesh network. This is where each customer's radio unit is an independent Router, allowing data to be forwarded from one node to another. This may be particularly useful where Line-of-Sight is limited, but has the disadvantage that if one customer switches off their router, another may lose their connection.
This is the technology that has seen widespread growth in homes, offices and public spaces – known as wifi. Very low cost, this type of equipment can be used for low range links and to extend networks both indoors and outdoors. The low cost means it opens up real possibilities for extending services everywhere.