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DFS Deadline Update
Note: Since the publication of the article below
last week the FCC officially ordered a 180 day extension of the
transition periods adopted in the 5 GHz Extension Order and
referenced in the article below. In essence, this now sets the
formal deadline for compliance with
Dynamic Frequency Selection(DFS) requirements for July 2006
for new products operating in the 5GHz band and July 2007 for
existing products already on the market that operate in this band.
Manufacturers of products affected by these new requirements should
take note of these new deadlines, as the initial compliance process
will likely take several months to complete.
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Dynamic Frequency Selection (DFS) and the 5GHz Unlicensed Band
by Mark Briggs, Principal Engineer at Elliott Labs
The advent of the 802.11a wireless market and the constant push
to open up new spectrum for unlicensed use created a requirement for
Dynamic Frequency Selection (DFS), a mechanism to allow unlicensed
devices to share spectrum with existing radar systems. The regulatory
requirements for DFS, along with requirements for Transmit Power
Control (TPC) and uniform channel loading have been adopted in the
US, Europe and Japan and are being considered by many other
regulatory domains looking at adopting the 5GHz bands for unlicensed,
and possibly licensed devices. In the next few chapters, I hope to
provide an overview of the current and proposed DFS requirements for
Europe and the proposed DFS requirements for the US.
European Union
ETSI standard EN 301 893 V1.2.3 [1],the European Union's
harmonized radio standard for unlicensed devices operating in the
5150 - 5350 MHz and 5470 - 5725 MHz frequency bands, was one of the
first standards to reference DFS. It specifies the types of waveforms
that systems operating in the 5250 - 5350 MHz and 5470 - 5725 MHz
bands should detect and defines threshold and timing requirements as
follows:
Channel Availability Check Time: The time a system shall monitor
a channel for presence of radar prior to initiating a communications
link on that channel.
Interference Detection Threshold: The minimum signal level,
assuming a 0dBi antenna, that can be detected by the system to
trigger the move to another channel.
Read the
full article
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A New Generation of Immunity Standards - Have you kept up?
by the Editors of Conformity
There's a new generation of commercial immunity standards, and
they bring some important changes in setup and test methodology. It
might be easy to overlook them if you aren't right in the lab
trenches doing the work. Some of these changes will improve test
repeatability and the quality of the data reported; some will create
a lot of work for lab personnel by making the set-up and calibration
processes more detailed, and in some circumstances, lengthen the
duration of testing. In this two part series, we will review the most
important changes that have occurred.
It is important to keep up with the changes that have occurred in
the basic immunity standards over the years. Some of these changes
are important, and will affect test geometry and equipment
calibration. The updates have been motivated by the desire to make
the tests more controlled and uniform in their delivery, and to
improve the information provided in test reports. In the area of
transient standards, both ESD and EFT have undergone significant
changes that affect test delivery and in some cases, the assessment
of immunity.
Read Part 1 of the
full article
This article summary was reprinted with permission from Conformity Magazine
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New DFS Testing Services at Elliott Labs! |
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Is your company prepared to meet the new Dynamic Frequency
Selection or "DFS", requirements (FCC Part 15, subpart E) for
products operating in the 5 GHz band? These formal requirements will
be going into effect this July here in the USA and they will soon be
expanded in Europe, Japan and other markets around the world.
Elliott Laboratories now offers a full range of DFS testing and
certification services. Elliott directly participated in the DFS
standards development process with the FCC and DOD and we have an
excellent comprehension of these requirements and the reasons for
them. In addition, we have invested in an Agilent Performance Signal
Generator and all additional test equipment required to meet the new
testing requirements.
Here in the USA, the DFS requirements will go into effect by July
2006 for new products and July 2007 for existing products already on
the market. If you would like to learn more about DFS testing and
certification services offered by Elliott Laboratories please email
us at
info@elliottlabs.com
or call 408-245-7800.
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684 W. Maude Avenue
Sunnyvale, California 94085
www.elliottlabs.com
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