4. Introduction
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Wireless communication is simply data communication without the use of
landlines. This may involve cellular telephone, two-way radio, fixed
wireless (broadband wireless), laser (free space optics) or satellite
communication systems.
Mobile wireless technologies are going to act as glue towards bringing
together the wired and wireless to share and distribute information
seamlessly across each other’s areas of reference.
Since from the beginning of wireless communications, there have been a
number of developments in each generation. Considering the future
generation of wireless communication i.e.; 4G.
5. Introduction(contd..)
4th GENERATION:
To achieve the goals of true broadband cellular service, the systems
have to make the leap to a fourth-generation (4G) network. 4G is
intended to provide high speed, high capacity, low cost per bit, IP
based services. The goal is to have data rates up to 20 Mbps. Most
probable the 4G network would be a network which is a combination of
different technologies (current cellular networks, 3G cellular network,
wireless LAN, etc.)
4G-cellular systems should not only be high-speed but also highcapacity, with low bit cost, high capacity with reasonable frequency
bandwidth, the cell radius of 4G-cellular systems shall be decreased
from that of present cellular systems.
6. Existing Technology
Satellites:
•Satellite is an artificial object which has been intentionally placed into
higher orbits.
•Satellite communication is the backbone of wireless communications,
and global positioning systems.
•Satellite in orbit of the planet cover huge footprint territories
•Satellites come in 4 types:
I.Geo-stationary
II.Sun-synchronous
III.Geosynchronous
IV.Low-earth orbit
7. Existing Technology(contd..)
Advantages of Satellite communication:
•High Bandwidth
•Coverage over a large geographical area
•Can be cheaper over long distances
Drawbacks of satellites:
Two main drawbacks of satellites. The first is signal latency, which
can cause problems in establishing broadband links. Most
telecommunications satellites are in geostationary orbit to remain
above a certain point on the Earth’s surface. That orbit, however, is
22,240 miles above the Earth, which means that a signal going up to
the satellite(uplink) and back to the Earth(downlink) travels nearly
45,000 miles, which equates to about a quarter of a second delay.
Even users of satellite voice links notice the delay.
8. Drawbacks of satellites:
The second drawback is that satellites are in space,
requiring expensive space launches, an additional level of regulation by
national space authorities, and an orbital allotment by the International
Telecommunications Union (ITU).
Also they include noise and interference due to large distance between
transmitter and receiver units.
9. StratelliteS
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A stratellite is similar to a satellite, but is stationed in the
stratosphere rather than on the orbit.
Stratellite is a “High Altitude Airship(HAA)”, which is positioned
approximately 13 miles above the earth, which provides the benefits
of a satellite like remote sensing, navigation and communication.
10. StratelliteS(contd.)
• Each Stratellite will have clear line-of-site communications
capability to an entire major-metropolitan area as well as being
able to provide coverage across major rural areas.
• The Stratellite is designed to carry certain payloads into the
Stratosphere determined by the requirements of the customer.
• A single unit could send broadband, mobile phone and digital
television and radio signals to a large area. The ‘unmanned’
Stratellite would be powered by solar cells and propelled
by electric motors.
11. Construction
•
Outer layer is made of spectra
is a fabric used in bullet proof
vests.
• Filled with a mixture of helium
and air
Consists of:
• Propeller
• Solar cells
• Regenerative fuel cells
• Helium gas bag
• Transponder
• Hybrid electric motors
12. Working
• Inside is filled with Helium gas,
as it is inert gas not flammable.
• The Helium gas expands
pushing out air and lifting the
airship.
• Uses solar cells sprayed on their
surface to generate electricity.
• The generated electricity drives
propellers that work with GPS
technology to keep the stratellite
stationary.
15. Advantages
• Decreases Signal latency
• Less expensive to launch
• Service an area of
300,000 square-miles
• Two-way high speed data
communication
• High speed broad-band
access even in remote
area.
• For a country two
stratellites are enough
instead of thousands of
towers
16. • Stratellites will carry over
20,000 pounds of radars
and other remote imaging
equipment, navigational
aids, and
telecommunications relays.
• Stratellites are planned to
remain on station for a year
at a time and will cost a one
fifth as much as a
comparable satellite
17. Disadvantages
• May lead to traffic problems in stratosphere.
• Would require efficient ground control and maintenance.
• So far, this technology remains non-commercialized,
and is in a prototype stage for further developments.
• Unlike with a satellite, a stratellite is at the mercy of the
weather.
18. Applications
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In environmental disasters telecommunication breaks down within
seconds, Re-installation of the infrastructure takes weeks or
months.
The Stratellite can be used as a floating mobile telecommunication
station for all telecommunication purposes and the transmission of
temporary data communication, telecommunication and TVprograms as well as long-term missions over metropolitan cities.
The Stratellite will allow subscribers to easily communicate in "both
directions" using readily available wireless devices.
In addition to voice and data, proposed telecommunications uses
include cellular, 3G/4G mobile, MMDS, paging, fixed wireless
telephony, HDTV, real-time surveillance and OTHERS.
Application case : “Google’s Project Loon”
19. Conclusion
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Probably the most "far out there" concept in this roundup, Stratellite
is actually much closer to reality than what you may think.
•
Once the defects of Stratellites have been overcome and become
more reliable, they play a vital role in the future generation wireless
communication.
•
This is a promising technology that could combine the best of
Satellite and wired Internet - fast with low latency and hugely
widespread, at least in theory.
