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Wireless WAN FAQs

 Radio Frequency   Free Space Optics

Radio Frequency

What happens when I get heavy fog or rain?
Nothing, adverse weather conditions do not affect RF frequencies below 11GHz.

What happens when a bird flies through my line-of-sight link?
Nothing, radio communications rely on a path know as the fresnel zone. This can be described a virtual balloon and as long as 60% of this “balloon” is visible at either end, then the link will not be affected.

I have a link that seems to perform better in the autumn and winter months than in spring or summer?
This is something that should have been outlined at the time of survey by your supplier. It is more than likely that there are trees in the link path. During the colder times of year there will not be any leaves on the trees, but in spring/summer performance will deteriorate due to the leaves growing and absorbing some if not all of the RF signal. This can be worse on a rainy day when the leaves are wet.

I work in a rented building and the landlord will not permit us to mount to the outside structure. Can I still have a RF link?
Yes, windows will attenuate RF signals very slightly but a good signal level / data rate can still be achieved. However, tinting in the glass or security wire that is sometimes in windows can mean higher levels of RF attenuation.

I want a building to building link, leased lines are far too expensive but security is of the utmost importance and I do not trust radio.
See our section entitled ‘Why Is It Secure?’
 

Contact us on 0870 752 6003 or use our online enquiry form for more information about radio frequency links and our wireless WAN solutions.

Free Space Optics

What happens when a bird flies through my link?
Ethernet will deal with this as if the medium is busy, ie. Hold off for random period of time then retransmit. Packet buffering by the switches at either end of the link will also help over come problems. The break in the beam will literally be a matter of micro seconds, however some switches may see the break as it would if the cable had been unplugged, resulting in the switch shutting the port down and causing a longer outage. This can be over come with simple commands reducing the port sensitivity levels.

What happens in heavy fog or rain?
A good rule of thumb is, if you can see 10% of your link, the link will work. For the occasion when there is very heavy fog, we would recommend a radio back up link that is not susceptible to bad weather.

I work in a listed building, and it is not possible to mount to the outside walls, can I still have a link?
Yes. The FSO heads can be mounted internally and pointed through the window. The grade of your glass will be obtained to ensure there is no tinting that may absorb or distort laser beam.

I want a building to building link, leased lines are far too expensive but security is of the utmost importance and am worried a FSO link can be easily tapped into.
See our section entitled ‘Why Is It Secure?’
 

Contact us on 0870 752 6003 or use our online enquiry form for more information about free space optics and our wireless WAN solutions.