Microwave links are a
well established technology with roots going all the way back to
experiments by AT&T™ in the 1930's. They are a reliable and
inexpensive way to move large amounts of data across the street or
across the state.
ISM Unlicensed S and C band links
Wired ethernet data
rates can be achieved across a few hundred feet or
up to a few tens of miles with the right equipment when it is properly
installed. The FCC has set aside a part of the microwave S (2GHz) and C
(5GHz) bands for "industrial, scientific, and medical" or ISM use. The
most common publicly recognizable service using these bands is 802.11
wireless ethernet, commonly known as WiFi. What makes 802.11 an
attractive alternative to wired services is that a license isn't
required. However, unlicensed does
not mean unregulated. Network engineers with only a cursory
understanding of RF theory have installed microwave links with little
planning and at best, have been disappointed by low performance, or at
worst, been fined by the FCC for causing interference with a licensed
service.
We use our extensive knowledge of radio and some
specialized equipment
to find a site for your antenna with low interference from adjacent
stations or select an antenna with a higher front-to-back ratio to
ensure a good signal-to-noise ratio. We then create a link budget to determine how much
gain the antennas at each end of the link need, and the lowest possible
RF power and narrowest channel needed to achieve the desired data rate.
Using
inexpensive equipment with integrated antennas, we can achieve
data rates of up to a hundred megabits per second over a considerable
distance, with a budget of only a few hundred dollars. With more
expensive and sophisticated equipment such as the Mikrotik™ NetMetal 5
802.11ac modem and Laird™ HDDA5W 1 meter dish, which features a
front-to-back ratio of 38dB, 32dBi of gain at 5.5 GHz and a beamwidth
of 4°, or the Andrew™ PX4F-52-N7A/A 4' dish featuring a 58dB
front-to-back ratio, 35dBi of gain and a 3° beamwidth, given a clear
line of sight, raw data rates close to gigabit
ethernet are achievable over
distances up to 30 miles using very little RF power. A properly
installed system enables a small carrier or business to maintain true
enterprise level connectivity.
Equipment estimates*
Laird
HDDA5W-32 1M 32 dBi Dual Polarized C-Band Dish Antenna, w/N-female
|
$399
|
Andrew
PX4F-52-N7A/A 4' 35dBi Dual Polarized C-Band Dish Antenna w/N-female
|
$1875
|
Mikrotik
NetMetal 5 802.11ac modem w/RP-SMA
|
$199
|
Mikrotik QRT 5
Integrated Antenna/Modem
|
$199
|
Mimosa
Networks 1Gb/S Modem w/N-female
|
$599
|
Andrew CNT-400
N-male/N-male jumper, 3'
|
$20
|
Licensed C and Ku Band WiMAx and TDM Links
FCC
Part 101 links are most
commonly used by cell carriers and ISPs for
backhaul of bulk data from sites without a connection to the SONET
backbone to a location that does, but they can also be used for remote
telemetry and automation of equipment such as substations and
compressor stations in the electric and gas industry, as well as
specialty communications systems like trunking radio systems, for
relocating received data from one location to another, and
studio-to-transmitter links in the broadcast industry.
We have experience installing a variety of
microwave antennas from Andrew™, including their Value Line, low performance Parabolic for Relocation, and the Sentinel high performance line.
Our capabilities include installing elliptical and flex-twist
waveguide and their associated pressurizer/dessicator systems,
installing antennas up to 6' in diameter and up to 240
pounds - anything larger will require additional equipment rental fees.
We can set you up
with a true carrier grade link
with guaranteed performance in the gigabit range, in either the C or Ku
bands. Andrew manufactures a line of dual-band, dual-polarization
antennas that when paired with four high speed radios such as the
Cambium PtP 810i can provide over 2 gigabits per second from a single
antenna.
We can replace obsolete radios and modems with
newer
models from Cambium Networks and Dragon Wave capable of IP and higher
throughput through your existing antennas.
We have experience installing indoor radios, where
the
modem and radio power amplifier are located inside the equipment
shelter and the signal is fed to the antenna through a long run of
waveguide, split systems where the modem is located inside the
equipment shelter and connected via coax to a power amplifier connected
directly to the back of the antenna, as well as all-outdoor systems,
where the run to the antenna is fiber and the modem and power amplifier
are built-in to the same device and mounted at the antenna. Indoor
systems are more expensive initially, but have lower maintenance costs
than fiber-to-the-antenna, which require a tower climb to replace modem
and radio components.
*Equipment
prices are speculative at the time of writing and are subject to change
without notice.
|