Don't be burdened with too much equipment. Travel light and stay
flexible for the best sounding remotes possible.
Any time a station broadcasts from outside the studio, whether it's
a promotional appearance, sporting event, news coverage or sponsored
appearance, the term "remote" is used to describe it. While these
events are unique in their own way, the same basic plan can make each a
Quality audio is the primary goal of any remote broadcast. The
bottom line determines the level of resources, both financial and
manpower, that can be dedicated to remotes, but even in the most
restrictive of circumstances, a small investment can yield a
substantial gain. The key to planning your station's remote broadcast
toolbox is to keep it portable and compact, while maintaining
The tools available for remotes, while not drastically changing, are
seeing advances and improvements in areas such as the extension of
audio link frequency response, data path provision, simplification of
operations, and the addition of layers of flexibility to handle new
More with less
Like most areas of business, remote broadcasts are pushing to do
more with fewer resources, whether those resources are equipment or
people. Providing simpler methods of setting up and running a remote
allows the engineering staff to focus on bigger projects.
Remote pickup transmitters are one of the more common methods of
establishing a remote link. Because RF usage is increasing, some
markets are forced to work with fellow broadcasters or find alternate
methods to establish a link. One area of RPU improvement is the
introduction of frequency-agile transmitters and receivers. In areas of
RF congestion, or for users working in more than one market, the
ability to easily change frequencies can help clear the way with a
Moseley has developed an enhancement for RPU users with a digital RF
link. The Aries 400S provides a 64kb/s to 128kb/s data path through a
V.35 interface. Many popular codecs can provide a V.35 output, and an
optional Layer II I/O is available.
Any time RF channels are used, proper frequency coordination should
be done. The Society of Broadcast Engineers has operated a volunteer
coordination program for many years. Contact the SBE (www.sbe.org) for the name
of the coordinator in your area before using any RF equipment,
particularly if you are working in a different market.
Hold the phone
The telephone is probably the most common way to establish an audio
link, particularly on short notice. Using the telephone by itself
works, but even a simple coupler can greatly improve the audio
response. With the proliferation of cell phones, the same convenience
is made even easier, but typically with even less audio quality. Again,
there are couplers and adapters to simplify audio and improve
integration into a cell phone.
Integrated equipment functions make for smoother event setups.
While cell phones are easy to use, they typically provide poor to
good audio quality, depending on the system and type of service (see
sidebar). One alternative to using interfaces and adapters with cell
phones is the Digital Cellcast from Marti.
The Digital Cellcast combines a cell phone and portable mixer into
one package. The unit works with TDMA dual-mode, TDMA tri-mode and GSM,
but not CDMA services. The transmitted audio uses the cell network; no
external audio encoding/decoding is done. Users contact a cellular
service provider and supplies the unit's serial number. The provider
then supplies a telephone number and system identifier for the user to
program into the unit.
ISDN codecs redefined the way stations establish high-quality links
with telephone company-provided lines. The higher data capacity of
digital phone lines lends itself well to remote use. Codec
manufacturers have also improved on their original designs by reducing
the size of the equipment and adding additional features, such as audio
mixers and multiple monitoring buses.
Not long after ISDN codecs were introduced, POTS codecs hit the
scene. The attraction to using POTS lines is that it is very easy to
locate an extra POTS line in a facility, whereas most ISDN line need to
be ordered in advance. POTS codecs work well for last-minute remotes or
situations where the budget cannot support the cost of ISDN
Codecs have quickly evolved into highly versatile devices.
Like their ISDN cousins, POTS codecs have also seen improvements
with enhanced mixers and better-sounding, more robust encoding
algorithms. The quest to achieve higher audio quality via a POTS line
is also pushing the line for using codecs with cell phones.
This idea brings together the best of both worlds: the true
portability of a cell phone with the enriched quality of an audio
codec. Currently, only GSM service is capable of a real-time data
transfer. Audio does not travel well through a packet data service.
Also, other cell services use various forms of data compression, which
are not compatible with the already aggressive coding used on the
GSM service currently is only available in larger metro areas as
shown in Figure 1. It is expected that GSM coverage will continue to
increase, allowing for greater opportunities to use cell phones and
codecs. The best quality available with a codec and GSM service is
currently about 5kHz.
In Europe, where GSM service has been available for some time, a
high-speed version of GSM, called HSCSD, is available. Services such as
this may become available as third-generation cell phone networks come
Simplifying the methods
Another way to reduce the equipment load is with a dual-personality
codec. These codecs give can function with both POTS and ISDN lines by
selecting the appropriate modem. These are well-suited for news
reporters and sports remotes where the connection may vary on location.
The dual-function hardware reduces the equipment load.
Figure 1. GSM service coverage in North America.
With the reduction in station operation staffs, some stations need a
way to run the station from the remote site. Some codecs provide a data
path for a low-speed serial connection. These paths are commonly used
to provide data between the station and remote site, or allow the
remote site to directly control a telephone system, automation system
or other station equipment.
Running the console remotely is possible with current designs based
on audio engines. Logitek is even adding a motorized fader option to
its NuMix controllers to provide visual feedback to the station
Remotely accessing the station's automation system allows the remote
site to upload audio for on-air playback. An example is SmartTouch, a
component of the Smarts Broadcast SmartCaster. The automation system
can be controlled and audio can be uploaded through the same telephone
line or through a separate communications link. The remote site can
also switch his feed directly to air if necessary.
In some applications, it may be necessary to use a POTS codec in an
unmanned mode, for example, during a weekly church service broadcast.
The station can call into the unit at the church when necessary.
TieLine has taken this one step further with its Pursuit POTS codec,
which has no user controls on it. The audio connections are made and
the levels are then controlled locally by a PC or over the POTS line by
an Express or Commander model codec.
Remote radio broadcasts are a staple of a station's routine,
providing a personal interaction between station and listener. In most
cases, the only image a listener has of a station is what he sees at a
remote. Sound quality is important for the listener not attending the
remote. Reliable, easy-to-operate equipment completes the image for the
attending listener. By using some of the current tools, your remotes
can sound better than ever.
|Types of cellular service
frequency division multiple
Used on all analog cellular systems. FDMA splits the allocated spectrum
into 30kHz channels. A single channel is used for each call.
time division multiple access
TDMA builds on FDMA by dividing conversations by frequency and time.
Digital compression squeezes the audio to about 10kb/s, fitting three
digital conversations into a single FDMA channel. This is compatible
with FDMA while enabling digital services.
TDMA does not vary the digital data rates. The time slot is occupied
by the call regardless of use. TDMA transmit about 600mW.
code division multiple access
CDMA systems do not have channels, but instead encodes each call as a
coded sequence across the entire frequency spectrum. Each conversation
is digitally modulated with a unique code (called a pseudo-noise
code) that makes it distinguishable from the other calls in the
frequency spectrum. The spread spectrum approach places the data across
1.25MHz pass bands within the 12.5MHz (cellular) or 60MHz (PCS)
CDMA offers three times the capacity of TDMA, but requires complex
deciphering and extracting the received signals. CDMA phones transmit
Global System for Mobile
Mostly a European system, but it is gaining popularity in North
America. GSM uses a modified, more efficient version of TDMA. GSM keeps
the idea of timeslots and frequency channels, but uses smaller
timeslots. Data rates start at 300b/s. Calls use as many time slots as
necessary up to a maximum usage of 13kb/s. Calls will jump between
channels and timeslots (frequency hopping) to maximize the system's
usage. GSM phones transmit about 1W.
Remotes To Go
By Chriss Scherer, editor
Not the same old broadcast van
You see them all the time: standard panel vans with a telescoping
mast and a few assorted pieces of RF and audio equipment. These remote
workhorses are customized for the types of remotes a given stations
performs. Some are heavily equipped for any possible situation, while
others are basic shells with an RPU transmitter and a microphone. Basic
setups may have only one power source available, but in more elaborate
situations, any number of power sources, including a portable generator
or the vehicle's alternator, drive the van's complement of
In most cases, the type of vehicle is chosen solely on its purchase
or lease price. There are times when a more unique vehicle can offer
more than just the necessary storage space and hauling capability. A
particular vehicle may be chosen because it fits the station's image
— a pickup truck with a shell for a country music station —
or it provides something that a traditional panel van cannot.
Here are four examples of stations that broke the mold on the
selection of their remote vehicle along with some notes on why the
particular choice was made.
This ambulance was converted into a remote vehicle and then later
rebuilt by Creative Studio Solutions. The spacious interior has plenty
of room for station staff to work and conduct interviews. The body
style also provides lots of storage space and multiple entry
Radio Noord, Amsterdam, The Netherlands
The other vehicles mentioned here are based on larger-than-usual body
styles. This is a move in the opposite direction. The small Mercedes
Benz A-Class is little more than 12 feet long. One of the rear
passenger seats has been removed to make room for an for an equipment
rack. While this particular vehicle is not available in North America,
it shows that a small vehicle can be used for remotes.
Photo courtesy of Broadcast Technical Projects BV.
WOOF-FM, Dothan, AL
box-style delivery van has lots of interior space. The usual broadcast
equipment is installed. Aside from the large space for the station's
logo, the vehicle also provides a dressing room for the station's
mascot, the WOOF Wolf. The rear roll-up door also provides easy
Photo by Hal Edwards.
WIOT-FM, Toledo, OH
When a local distributor retired the vehicle, the stations purchased
The scrolling doors provide easy access to the vehicle's generator,
Marti RPU receiver and transmitter and PA equipment. Because of the
vehicle's size, it makes a very large presence at remote sites. The
vehicle's driver must hold a commercial driver's license. Photo by