A Guide for ISPs Using Wireless (or Thinking of Using Wireless)

A Quick History Lesson

Customers naturally tend to assume that reliable, high speed connectivity can only be delivered via a traditional fibre or copper service from a telco such as BT. The fact is that wireless technology has been at the core of the UK telecommunications network since the early 1950s. BT’s predecessor, the General Post Office, constructed a chain of microwave links that were designed to provide resilient communications in the event of nuclear war. The most famous part of this network is the BT Tower in London which is still used as a network point of presence today. BT still have thousands of wireless links in their network which provide coverage in the very hard to reach areas of the UK.

Don’t cities have great broadband networks anyway?

The fact is that the UK telephone network was never designed to carry high speed data. Most premises are connected via a copper cable of some kind that carries one or more voice lines. These lines often run many miles back to a local exchange where they are then generally switched onto the main BT 21CN fibre network. The problem is that these copper lines are often old and not great quality which straight away reduces their ability to carry data. In some areas they are even aluminium rather than copper which causes even more problems. The longer the cable run from the exchange the slower the eventual data rate.

BT Openreach are rolling out Superfast Broadband to many areas of the UK, but the performance of this service is still limited by the existing copper network.

Regular ISPs will tell businesses that the only way to get reliable, high speed broadband is to get a dedicated connection, or leased line, of some kind. This could be delivered over copper (such as an EFM circuit up to 35Mbps) or fibre optic (up to 1Gbps). EFM is not available and fibre is generally very expensive and often carries significant installation costs.

Why Wireless?

Using wireless technologies means the ISP can completely bypass the existing local telco network. The wireless link connects directly into the ISP’s core network and then directly into a main internet exchange or data centre. Wireless links can be installed very quickly as there are no roads to dig up meaning customers can be connected much more quickly than via a traditional operator.  Using licensed spectrum (such as Purdicom’s private 32GHz band) or Millimetre-wave allows for very high capacity links with extremely high availability.  Wireless links are also re-deployable, so if your customer moves or only requires a temporary connection, the wireless link can easily moved – unlike fibre!

Isn’t fibre broadband faster than wireless?

Firstly, much of what BT are calling ‘fibre broadband’ is actually delivered over copper. It only connects to fibre at the local street cabinet which may be some distance away. This service (EFM as a business product) provides ‘up to 35Mbps’. The reason they say ‘up to’ is down the issues listed above – the speed degrades over the copper so they will always struggle to accurately calculate the speed. Actual fibre optic delivered broadband can go up to 1Gbps but it is pretty expensive as you would imagine. Modern wireless technology allows us to connect at speeds in excess of 2Gbps if required. Isn’t fibre more reliable? Fibre is very reliable (unless someone digs it up) and would be many people’s first choice and until a couple of years ago the only way to get gigabit would be over fibre. We are transmitting through the air and we know how the radio waves are going to behave. We also factor in bad weather meaning the links have a very high availability even in poor conditions.

Typically a wireless system would have an availability of around 99.99% up time. In the highly unlikely event of a system failure it is a simple job to swap out the antenna, if someone digs your fibre up that’s a different matter!

Is this wireless technology safe?

All equipment goes through strict testing and certification processes to ensure that it complies with the relevant safety regulations. All kit is also CE certified and complies with Ofcom regulations. The wireless antenna on the side of your building is highly directional and transmits a very narrow beam of signal back to a receiver. There is no propagation of radio into the building it is located on. To put it in perspective, this transmission power is about the same as your wireless LAN access point but focussed in a single direction.

Will it cause interference with my current WiFi system?

No – these high speed systems use different parts of the radio spectrum, generally 6-80GHz. WiFi systems operate in 2.4 and 5GHz pieces of spectrum. Do I need planning permission for the antenna? Generally speaking the answer is no. The antennas are small and tend to be classed as ‘de-minimis’ by local planning authorities and so do not require planning permission. Typically the antenna is around 30cm in diameter so very small and inconspicuous.

How long does it take to install?

The equipment required is available ‘off the shelf’ from suppliers in the UK. This means that installations can usually be carried out very quickly. The wireless system outside is connected via single CAT5e cable to a power-over-Ethernet supply located indoors, meaning there is no need for mains power outside. This means the actual installation is very quick, typically one day or less.