PMP Synchronization Solutions User Guide
Interference and reliability
PMP-0297 007v001 (January, 2017)
1-2
Interference and reliability
In the unlicensed wireless environment, interference can be defined as unwanted,
competing radio signals in the same frequency band. These interfering signals can disrupt,
delay and reduce the reliability and quality of your network traffic and performance. In
licensed frequency bands where no outside signals are competing, the issue is self-
interference, i.e., your own network’s signals competing with each other. In either case, the
results go beyond lower quality transmission; they extend to customer dissatisfaction, loss
of competitive advantage and decreased return on investment.
Exclusivity and free use of spectrum
There are two types of frequency bands in which wireless networks operate: the licensed
and unlicensed bands. Characteristics of each include:
Licensed frequencies
Licensed frequencies are bands reserved for the exclusive use of a public/private entity.
Since the spectrum is clean and clear with no RF emitters (controlled by other entities)
operating in the same frequency, wireless system reliability is greatly improved.
Interference issues are largely confined to self-interference problems.
Unlicensed frequencies
Frequently described as a “Free Use” environment, unlicensed frequencies provide
spectrum that is available to virtually anyone that wants to use it. Signals from different
transmitting organizations and entities may compete with one another for space, creating
an environment in which interference and ambient noise — as well as self-interference —
can be significant impairments to reliable communications. The sheer number of the
competing signals in unlicensed spectrum places a premium on ensuring that the
equipment you use is of exceptionally high quality and design.
