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700MHz Auction-DTV-White Space Devices
The Federal Communications Commission (FCC) has recently adopted
changes and approved wireless devices that can affect the operation
of wireless microphone, wireless intercom, wireless IFB, and wireless
In Ear Monitors.
PRODUCTION WIRELESS SERVICES has always provided information, service,
support and sales for most professional wireless products. PRODUCTION
WIRELESS SERVICES will continue full service and support during
and after any upcoming changes.
There are several radio frequency issues that exist now and will
occur in the near future. The following is a brief explanation of
the issues and how they affect wireless operation. This information
may help identifying problems and finding solutions.
Most wireless systems make use of VHF and UHF television bands between
150MHz and 806MHz. These correspond to television channels 7 through
69. Wireless use generally occurs within the available RF areas
between the used analog and digital television channels.
There are three main issues that somewhat interact with each other.
The upcoming changes are scheduled to occur on or after February
17, 2009. The three main issues are:
• 700 Megahertz Auction
• DTV Change Over
• White Space Devices
700MHz AUCTION
The FCC recently auctioned off television channels 52 through 69
(698MHZ to 806MHz). The FCC has mandated that all existing radio
operation and television above 700MHz cease. This radio Frequency
(RF) band was purchased by Verizon, AT&T and others. Use of this
newly acquired RF band may occur as soon on February 17, 2009. Depending
on city, location and yet to be seen coverage and RF levels, RF
interference is expected for wireless systems within this 700MHz
band. Many facilities that use wireless have already adopted the
no use policy. This auction severely affects VEGA U2020 users as
all ranges of the series operate above 700MHZ.
DTV CHANGE OVER
The FCC has mandated that all full power television stations cease
the analog (NTSC) television signal and only broadcast the digital
television signal (DTV). This "DTV Change Over" is scheduled for
February 17, 2009. Additionally, all licensed users and existing
television stations currently within the 700MHz band will be moving
to television channels between 7 (174MHz) and 51 (698MHz). These
changes may create changes in currently open television channels
that wireless now operate. Possible RF interference can occur. Any
unused television channels now become known as "white spaces". Most,
if not all VHF and UHF banded wireless systems will have to operate
within these white spaces.
WHITE SPACE DEVICES
On November 4, 2008, the FCC approved the future use of "White Space
Devices". The "White Space Devices" or "TVBD" (television band devices)
are destined to operate within white spaces. Depending on the RF
level, location and proximity to these devices, RF interference
to wireless systems is possible. The devices are required to be
"geo-specific", use data bases of existing "licensed" wireless users,
and use spectrum sensing technologies. The TVBD devices present
a serious interference problem for wireless use. The majority, if
not all, wireless systems are not licensed. Many productions and
traveling users make use of wireless systems only for a small portion
of the day. Data bases and spectrum sensing technologies may not
help in avoiding RF interference to the wireless systems that share
the same white space.
The future for wireless appears bleak. Is there any good news?
A LITTLE GOOD NEWS
Many manufacturers offer re-banding or re-programming policies.
Sennheiser, Telex/EV, and Lectrosonics provide
these services for select systems. Pricing is a fraction of the
cost to purchase a new system.
Sennheiser and Shure recently introduced rebate or
"Trade in Programs" that offer rebates back to current users of
"qualifying" systems now in the 700MHz band. Each of the manufacturer’s
programs is somewhat different, but both provide incentives for
replacing both current and obsolete wireless systems operating above
700MHz.
Although Vega has not produced any wireless products in over
two years, Shure and Sennheiser offer similar wireless
microphone systems that operate below the 700MHz band. There are
several series of wireless systems and are competitively priced.
Most current HME and Comtek products are largely unaffected.
HME currently offers the 4/C range found in the PRO850 series wireless
intercoms. HME will modify the upper range of the 4/C range on all
systems sold after February 17, 2009 in order to avoid frequencies
698MHz and above. The HME service department will install this modification
as a “no charge” for systems under warranty. Owners of older, “out
of warranty” PRO850 systems requesting the modification may be subject
to a small fee. Comtek is soon to be providing systems that operate
in the 169 “Hydrological” band (169MHz to 171.925MHz).
Clear Com, HME and Telex offer alternative
frequencied systems that operate outside of the VHF/UHF television
bands. These systems provide wireless communications in the 1.9GHz
and 2.4GHz range. This avoids most wireless microphone and wireless
compatibility issues.
There are thousands of users that still make use of the "old" VHF
and "traveling" frequencies. Although not many manufacturers build
systems in these bands, hang on to any VHF or "Traveling" frequencied
systems that you may have or find. These are additional frequency
alternatives to what may be interference filled white spaces.
PRODUCTION WIRELESS SERVICES also has compiled a listing of white
spaces in over 60 cities and television markets. This information
is useful when selecting operating frequencies upon and after the
DTV Change Over. And as always, PRODUCTION WIRELESS SERVICES will
continue to service and support most makes of current and obsolete
professional wireless systems. VEGA, SHURE, SENNHEISER, HME, CLEAR
COM, TELEX, LECTROSONICS, COMTEK and many smaller brands of obsolete
wireless can still be supported as long as unique parts are still
available from the manufacturers or in stock.
Please email or call with any questions or issues. Please contact
us and we will post the answer here on our site!
Thank You,
Greg Parsons
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