A common request from IT managers for companies is to link multiple buildings together on a business park or industrial park. The requirement can often be to extend the network LAN of the server at a main office and/or provide good internet connectivity to buildings that have none or very poor service.
The reason for these kinds of connections are usually to save on costs from getting multiple leased lines for each building, or digging up the road which can be very time consuming and costly. Using a wireless bridge, the cost can be a fraction of the overall costs of installing any the of leased line/physical fiber connection mentioned above. A wireless bridge can also be used as a diverse redundancy link as a back up to a leased line. Wireless bridges can also be used for Disaster recovery to secondary sites with duplicate servers.
The kind of buildings that are often connected in this way are some of the following;
- 2nd office
- Manufacturing plant
- Security office
Difficulties can arise from achieving a link. Most common of all these will be the lack of line of sight. When it comes to wireless bridge connections, line of sight is quite important in order to achieve a stable, high bandwidth, high availability link.
If you have trees in the way, then depending on how much obstruction the tree is causing will differ in every case, but it will certainly cause disruption to a service and possibly stop a link altogether. Trees have a variable effect on radio signal. They will sway with the wind, leaves bloom and fall during different seasons, they grow, collect water during rain fall. All these variables cause different types of disruption to radio signal, so you may get better connectivity during autumn and winter periods, and terrible service during spring and summer seasons. If at all, trees should be avoided from the line of sight pathway.
Other buildings can often become an obstruction for line of sight. Ways that we have go around the problem is to raise the mount height of the radio to get above building heights. This can be done in a number of ways. This includes the following methods; -
- Mounting a long steel pole on the side the building (stability is achieved using steel rope guy wires to anchor the pole at 3 points
- Flat roof Non penetrating Roof mounts which are anchored using concrete weights. This is useful if we are not allowed to mark the building in any way
- Pitched roof Non penetrating Roof mounts which are anchored using concrete weights. We can use this method if there is no way to mount the hardware and we need height above the roof
- Standalone mast. This can come is a number of varieties. Lattice masts can get very high, telescopic masts are quick and easy to deploy.
A problem that is becoming more common is radio interference. This really only applies to the 5Ghz frequency, which is becoming the easiest way and most cost effective way achieve links. Because of this, the it is not unusual to see a lot of links being used in close proximity on a business park. The way to get around this is to use a Millimetre Wave radio (60Ghz – 80Ghz are most common) which will ensure interference free operation.
In summary, creating a wireless bridge is a viable option to provide a high availability link to another site, which can save on money and time to implement.