Solutions for the
Transportation of High Speed Video, Voice, and Data using Free Space Optical
Laser Systems in Hawaii
Organizations today need high-speed,
secure means to link their video, voice and data networks. Fiber optic cable is
often the preferred method because it provides high bandwidth, protocol
independence, security, and low-maintenance transmission over long distances,
reliability, low-bit error rates, and is easy and safe to use. However,
trenching cable can be prohibitively expensive or logistically impossible.
Cable cannot easily accommodate
mobility should an office be relocated and can fall victim to breaks caused by
construction or road repairs. Other options are leased lines and microwave
systems. However, costs for both of these solutions can be excessive. While an
organization owns its fiber optic equipment, it does not own the leased-lines,
nor can it control price increases.
Maintenance for microwave systems can be
very expensive, and licensing must be obtained from the FCC, which can delay
deployment or bar it completely in areas where frequencies are no longer
available. Some communities ban the use of microwave systems for aesthetic or
health reasons. The need for an alternative technology to link video, voice,
and data networks that will provide the speed and other advantages of fiber
optic cable, but is more affordable and logistically more advantageous in many
applications, is realized using wireless optical communication technology.
Laser link Optical Data Communication Systems are designed to
accommodate expanding high-speed networks, Laser link systems are capable of
transmitting higher data rates than traditional wireless solutions. The products
incorporate technologies fostered by U.S. government-sponsored satellite laser
communications programs.
Laser link systems provide a reliable,
affordable, quickly deployable, secure, high-speed protocol-independent means
to link local and wide area networks (LANs and WANs) in different buildings or
locations.
Laser link systems provide an alternative
form of optical video, voice, and data transfer when fiber is too costly or
logistically impossible to install. Requiring no FCC licensing. Laser link
systems are also an easily deployable and affordable alternative to leased
lines or microwave systems.
Delivering data rates from 10 to 622 Mbps
per second and ranges up to 8 kilometers to suit a variety of needs, the Laser
link systems can be mounted on the top of buildings or other suitable
locations. They provide excellent video, voice, and data links for
multi-building organizations, such as; condominiums, hospitals, government
agencies, utility, telecommunication companies, and manufacturers.
They can be used to solve other
logistical problems, such as crossing difficult terrain, expressways,
waterways, and international borders. The laser link units also can be deployed
quickly for temporary connectivity needs, such as at exhibitions, sporting
events, emergency and disaster recovery scenes and military operations.
The laser link may be designed for long
distances of up to 8 kilometers (5 miles). Providing data rates of up to 230
Mbps, the laser is ideal for wireless applications requiring rugged performance
at longer distances. Systems capable of transmitting up to 622 Mbps at
distances up to 3.5 kilometers (2.2 Miles), may be designed for applications
requiring increased throughput.
To fill the growing need for
shorter-distance links, with a maximum range of 400 meters and data rates of up
to 155 Mbps, the laser link is ideal for transmitting data across a city
street. The laser link can be modified to extend the transmitting distance up
to 1-kilometer (.62 mile). Enhanced laser links offers wireless data links at
distances of up to 2.5 kilometers and data rates of up to 155 Mbps. The laser
link with more lasers, can transmit at distances up to 5 kilometers at data
rates up to 155 Mbps.
1. How do Laser wireless optical communication systems work?
The transmission
process is similar to what takes place inside a fiber optic cable, but in
wireless optical communication the light travels through the air. Laser
wireless optical communications systems use infrared laser light to transmit a
digital signal between two transceivers. The transceivers must be securely
mounted atop buildings or other suitable locations. In order for the digital
signal to be transmitted and received, there must be clear line of site between
each Laser unit. In other words there should be no obstructions such as trees
or buildings between the transceiver units.
2. How do Laser systems connect to data networks?
The Laser systems
interface to network switches, hubs, bridges or routers with multi-mode fiber
(850nm or 1310nm) and standard ST connectors. The network configuration is
designed as if the Laser were a fiber optic cable running between the two
sites. Laser systems provide protocol transparent connectivity at the physical
layer, and do not provide any error-checking, bridging, routing or repeater
function on their own. Delivering data rates of up to 622 Mbps, Laser systems
can provide connectivity for most standard network data formats.
3. What data rates and distance
requirements can Laser systems accommodate?
The standard line of commercial Laser
products provides data rates from 10 to 155 Mbps at distances of up to 3.75
kilometers (2.33 miles). Data rates up to 622 Mbps and longer-range systems are
also available as custom products.
4.What organizations can benefit from a
Laser system? Ranging from
hospitals, banks and telecommunications companies to municipal and military
installations, Laser systems are filling a variety of wireless data
communication needs the world over. For private corporate networks, Laser
systems provide a very high bandwidth link between sites without the recurring
costs of leased lines. For high bandwidth applications such as Tele-medicine or
videoconferencing, the Laser provides new alternatives to installing fiber
optic cable between sites where it is very expensive or impossible to lay. For
temporary network connectivity needs, such as at exhibitions, conventions,
sporting events, or disaster scenes, high bandwidth links can be easily and
quickly provided using portable Laser systems. I n addition, Laser systems are
also used as high-speed wireless backup for fiber optic cable and as "Last
Mile" solutions, connecting customer sites to fiber backbones.
5. Where can the Laser units be installed?
Laser systems are
typically mounted on the sturdiest areas of buildings or other structures,
where there is minimal exposure to vibration, wind sway, and thermal expansion.
Usually the corner of a building’s roof is the best location, or as close as
possible to an outside wall. Mounting to masonry is preferred, as wood is very
susceptible to thermal and moisture expansion.
6. How do extreme temperatures affect the Laser?
Laser units are designed to withstand a wide
range of conditions and temperatures. The standard operating temperature range
is -22° to +122° F (-30° to +50° C). For very extreme conditions, designs for
additional heating or air conditioning compatibility for the housings are
incorporated.
7. How quickly can Laser systems be up
and running? Once the sites have
been prepared with proper power and data interface connections, and mounts have
been securely affixed, a Laser system can provide connectivity within a few
hours.
8. What wavelengths do Laser systems use and what are the power requirements?
Laser systems use
infrared wavelengths of 780 nm and 850 nm. The standard systems require 110
volts AC power, most Laser products require only 150 watts.
9. What is the Bit Error Rate?
All Laser
availability numbers assume a BER or 10-9. Some Laser systems are compatible
with ESCON, which requires a BER of 10-12.
10. What are the advantages of Laser wireless optical communication systems over fiber optic cable connectivity?
For many locations
where organizations need LAN or WAN links, fiber optic cabling may be difficult
or impossible to use when sites are separated by water or mountainous terrain
or by streets where installing cable would be prohibitively expensive or
logistically unfeasible. When quickly deployed connectivity is needed, a Laser
system can be installed in much less time than it would take to install cable.
Laser systems can eliminate the need to run fiber optic cable for temporary
connectivity needs such as at conventions, sporting events or disaster scenes.
11. What are the advantages of Laser
wireless optical communication systems over microwave connectivity? A major advantage is higher bandwidth
capability. Currently, no single microwave system can provide 622 Mbps of
throughput. Laser units are smaller than most of the antennas required in
microwave systems, providing easier installation In addition, Laser systems
offer great cost advantages over microwave and require no licensing, a process
which can cause installation delays or prohibit use of microwave systems
altogether.
12. Are Laser systems secure?
The infrared
frequencies of light used in Laser systems are invisible to the naked eye and
confined to a narrow path. Interception is nearly impossible and would require
knowledge of the physical location of the beam, as well as the ability to enter
the beam path directly using complex detection electronics to receive the
transmission. This type of interruption would break the data signal and would
be detected by the user. Many of our customers use Laser systems to transmit
sensitive and confidential information including legal and financial
information, medical records and military intelligence.
13. How does the weather affect the performance of the Laser?
Lasers were designed
for optimal performances in all weather conditions. Occasionally, short
interruptions can occur if heavy fog, snow, smoke or atmospheric scintillation
blocks the line of sight between the Laser units. This rarely happens, but
worldwide weather statistics are used in advising customers when they are
selecting a Laser system. To ensure optimal performance in severely adverse
weather conditions, multiple transmit aperture technology can be implemented.
For organizations needing 100 percent availability of their networks, Laser
systems can be backed up by a lower bandwidth technology (such as a spread
spectrum radio or low data rate leased line).
14. Does sunlight affect the performance of the Laser?
Generally, sunlight
does not affect link performance because Laser units employ interference
filters to block out wavelengths of light other than laser. However, to avoid
any chance of sun interference, Laser systems should be installed so that the
sun will not be directly behind either one of the transceivers. In the very
worst case, the sun would only be an issue for a few minutes a year.
15. How do birds and other temporary obstructions affect the Laser?
While the signal can be disrupted when
something temporarily breaks the beam path, most network protocols will handle
the disruption by simply resending the data, and the break will not be noticeable
to network users. If an interruption does occur, the Laser will immediately
reestablish the link once the obstruction has cleared.
16. Are Laser systems safe?
Laser systems
incorporate low power semiconductor laser diodes at infrared wavelengths and do
not create a hazard to humans or animals. The Laser systems are safe for
viewing at the aperture as determined by the American National Standards
Institute. The Center for Devices and Radiological Health (CDRH), a branch of
the U.S. Food and Drug Administration that reviews manufacturer's compliance
with safe wireless optical production, and operation guidelines, has approved
the manufacture, and marketing of wireless optical communication systems.
17. Do Laser systems require any frequency
licenses or safety permits?
Narrow beam wireless optical communication
systems such as Laser do not cause and are not subject to interference normally
associated with RF systems. For this reason, there are no user FCC licensing
requirements for Laser products.
18. What maintenance is required on Laser systems?
When mounted and
installed properly, the Laser systems require very little maintenance. Network
managers should monitor the alignment of the system periodically and adjust it
if needed. The windows on the front of the units' weatherproof housing should
be cleaned with a regular glass
cleaner and soft
cloth or lint-free paper towel.
19. Can Laser systems transmit and receive through glass?
Lasers can
effectively transmit through glass. However, the number of glass surfaces
(single or double pane), tinting, reflective coatings, and quality of the
windows need to be taken into account prior to system specification and
installation.