Stratellite Full Seminar Report and PPT
Wireless communication is simply data communication without the use of landlines. This may involve cellular telephone, two-way radio, fixed wireless (broadband wireless), laser (freespace optics) or satellite communications. 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.
The paper firstly introduces the wireless communications and then switches to fourth generation in wireless communications.
The paper then discusses about High Altitude Airships, the “STRATELLITES” which are actually unmanned Kelvar balloons filled with helium which are used instead of towers for wireless communication, each of which replace hundreds of towers and reduce the cost of wireless communications. They also overcome the disadvantage of simple towers which could not provide proper coverage in the hilly areas.
INTRODUCTION TO STRATELLITE
Wireless communication is simply data communication without the use of landlines. This may involve cellular telephone, two-way radio, fixed wireless (broadband wireless), laser (freespace 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.
HAPS have the potential to become the third communications infrastructure after terrestrial and satellite communications. The platforms keep their positions at about 20 km high in the stratosphere. By optical intercommunication links, they make a mesh-like network in the sky. A broadband access link is the link between the platform station and the user station.
The typical bit rate of the access link is 25 Mb/s for most fixed and portable terminals, while a several hundred megabits per second link is available for limited fixed terminals with antennas larger than the typical ones. Because of using millimeter-wave bands, a small antenna with high gain is feasible. For example, a bit rate of 144 kb/s can be provided for vehicles by only a 5 cm dish antenna with 20 dB gain
1.3 4G MOBILE COMMUNICATION
Some of the systems for future mobile communications are:
- Broad-Band Wireless Systems
- Intelligent Transport Systems
- High Altitude Stratospheric Platform Station Systems.
1.3.3 HIGH ALTITUDE STRATOSPHERIC PLATFORM STATION SYSTEMS (HAPS)
HAPS has the potential to become the third communications infrastructure after terrestrial and satellite communications. The platforms keep their positions at about 20 km high in the stratosphere. By optical intercommunication links, they make a mesh-like network in the sky. A broadband access link is the link between the platform station and the user station.
The typical bit rate of the access link is 25 Mb/s for most fixed and portable terminals, while a several hundred megabits per second link is available for limited fixed terminals with antennas larger than the typical ones. Because of using millimeter-wave bands, a small antenna with high gain is feasible. For example, a bit rate of 144 kb/s can be provided for vehicles by only a 5 cm dish antenna with 20 dB gain.
A “stratellite” is a high-altitude airship (HAA) “25 times larger than the Goodyear blimp” employed much like a satellite for remote sensing, navigation, and communications. Instead of being stationed on orbit, stratellites are positioned in the stratosphere approximately 13 miles above the Earth.
This altitude places the airships above both commercial air traffic and weather effects but significantly lower than standard low earth orbits. From this height stratellites can service a 300,000-square-mile-area. The North American Aerospace Defense Command (NORAD) projects that eleven such airships could provide radar coverage of the entire maritime and southern borders of the United States.
Construction Of Stratellite
The initial Stratellite was 188 feet long, 60 feet wide and 42 feet high. It is provided with a new steering method which uses a hybrid electric system that drives large, slow-turning propellers. This gives the airship helicopter-like agility by being able to move both up and down, and side to side.
The outside layer, or “envelope,” is made out of a high-tech material called Spectra – a fabric used in bullet-proof vests and parts of space shuttles. Spectra contains fibre 10 times as strong as steel of the same weight and has the unique feature of being easy to cut but virtually impossible to tear.
The inside layer, made from a thin but strong polyester film called Mylar, is fitted inside the envelope and filled with a mixture of helium and air as helium is an inert gas and is therefore not flammable. With this design, the helium expands as the airship rises, forcing air out and lifting the airship. The cycle continues, allowing the airship to gain more and more altitude until the helium has expanded to fill the envelope completely. Because the pressure is so low inside the envelope, a puncture would only result in a very slow leak, taking a long time to totally deflate.4,000 pounds, and later models are expected to 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 fifth as much as a comparable satellite
- Length: 245 ft in (75 m)
- Width: 145 ft in (44 m)
- Height: 87 ft in (26.5 m)
- Volume: 1.3 million ft3 (420,000 m3)
- Service ceiling: 70,000 ft (21,000 m)
- Dual envelopes, made of Dynamo (sometimes called Spectra)
- Navigation: 6 onboard GPS units connected to the ship’s engines
- Payload capacity: 3,000 lb (1,451 kg)
- Cruising altitude: 65,000 ft (20,000 m)
- Lifting gas: Helium and Nitrogen
- Line-of-sight: 300,000 mile² (480,000 km²)
- Maximum duration aloft: 18 months
2.4 STRATELLITE TECHNOLOGY AND ADVANTAGES
Stratellites are actually unmanned Kevlar balloons filled with helium. They use thin-film photovoltaic cells sprayed on their surfaces to generate electricity, which drives propellers that work with GPS technology to keep the stratellite positioned over one spot on the Earth’s surface. Prototype airships are projected to carry payloads as large as 4,000 pounds, and later models are expected to 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 fifth as much as a comparable satellit
- 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
2.5 DRAWBACKS OF SATELLITES
These firms are becoming involved with stratellites because they avoid the 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, (i.e; in the area called CLARKE’S BELT), 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.
Fig 2.4 stratellite transmission
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). Stratellites remain in national airspace and are
Stratellites remain in national airspace and are therefore not subject to these licensing and technology requirements. However, they do make use of space technology and, as stated above, are in development by at least one space industry firm.
At an altitude of 13 miles, 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 idea, if successful, would be revolutionary for underserved areas where broadband is not as popular because the areas are too expensive to reach by telephone or cable network.” “Existing satellites provide easy ‘download’ capabilities, but because of their high altitude are not practical or commercially viable for a ‘two-way’ high speed data communication. The Stratellite will allow subscribers to easily communicate in ‘both directions’ using readily available wireless technology.”
This means that subscribers can send and receive information using the network, like the current broadband internet system but, without the wires, cables and cellular towers.
2.7 APPLICATIONS IT ENABLES
Once a Stratellite network is in place, it will provide a national broadband wireless network that will provide voice, video, and broadband internet access to all parts of the country. By linking several Stratellites together they can provide a wireless broadband network that will cover thousands of miles. With a Stratellite network, subscribers will be able to sit in their homes and be connected on their laptops to the internet at high speed. If subscribers need to go to the office, across town, or even to another city, they can close their laptop and take off, reopening the laptop at their new destination and still be connected to the internet. 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 TV-programs as well as long-term missions over metropolitan cities.This would allow subscribers the ease of not having to find local access numbers, tie up phone lines, deal with modem hassles, and more importantly, slow speeds. In addition to internet use, “proposed telecommunications uses include cellular, 3G/4G mobile, MMDS, fixed wireless telephony, HDTV, real-time surveillance and others.
2.8 STRATELLITES AND TELECOMMUNICATIONS
Stratellites offer a window of telecommunications opportunity. Effectively, a Stratellite positioned over a major metropolitan area could act as a cell tower thirteen miles high. A Stratellite, equipped with the appropriate transponders, could manage the wireless needs of that entire metropolitan area. Transponder access could be leased to broadband users such as Internet Service Providers (ISP’s), cell phone companies, television networks, radio stations, various levels of government, and to corporations with large broadband requirements. These consumers could then resell access to end users, for residential Internet access, for example.
None of this type of business or wireless use is innovative, so existing regulatory schemes and business models cover Stratellite communications. In fact, Stratellites employed in this manner would make use of existing spectrum allocations, at least initially, and not require expensive bandwidth acquisition. Additionally, the marketing of such links would be virtually identical to current marketing. By increasing the utility and availability of the type of link that has, until now, been restricted to satellites, firms can bring broadband links to new areas, provide for increased usage, and service larger markets without any fundamental change in operations.
2.9 STRATELLITE CHALLENGES AND BUSINESS OPPORTUNITIES
Though the opportunities for increasing broadband links and for profit are enormous, Stratellites are still in their infancy. They present several problems that have yet to be fully addressed. The public may be concerned about such large, unmanned payloads stationed above metropolitan areas and recent developments in sub-orbital flight could eventually lead to traffic problems in the stratosphere. More importantly, critics question whether technology really exists that can keep Stratellites on station for such long periods of time. Once these concerns are overcome and working Stratellites are available, the potential exists for vastly expanding broadband links.
Some telecommunications providers, such as Sanswire Technologies, have recognized this marketing opportunity and already have formed joint ventures with the space industry and balloon-makers. However, in addition to marketing, Stratellites will require ground control and maintenance, and used Stratellites will require refurbishment before redeployment, tasks which the manufacturers and marketers may well lack the capacity or desire to perform.
As broadband requirements increase, Stratellites present a mobile, low-cost, high-capacity alternative to satellite relays and cell towers. In remote areas, over the oceans, in metropolises, and in areas stricken by disaster, Stratellites will immediately provide broadband access and broadcast capacity. Prototypes are in testing and development now.
The potential benefits of Stratellites are so great that it is not a question of whether the technological problems will be solved, but when. Soon Stratellites will be bringing the Internet, cell phone access, radar monitoring, and radio and television service to all corners of the globe.
2.10 MARKETABILITY AND COSTS
In addition to providing “two-way” communication, Stratellites make more sense than wireless systems and satellites: (1) there is no use of huge ugly cellular towers, since they are in orbit, and (2) they are far cheaper to launch, maintain and upgrade than satellites. However, there are still two big concerns: if Stratellites will actually work, and their cost as launching things into space (or near space) can be costly.
Using wireless equipment, a company would have to install over 14,000 cellular towers to cover the same area as Snaswire’s proposed Stratellite based national wireless network. That means that there will be over 14,000 more ugly towers to hide. In addition, this technology will make the need for expensive cabling obsolete.
“One of the many advantages our High Altitude Airships have over satellite technology is that the payload can easily be recovered, upgraded, and re-launched in a matter of hours.” Thus, each airship can be retrieved and re-used.
Even if these costs are kept down Stratellites do not come without problems or doubters. They have to float inside 200 to 300 meter box and that’s hard for an airship. After you solve that problem, you have to create a service that can perform better and cheaper than DSL. In addition, Stratellites are susceptible to the same kinds of interferences that satellite systems currently are.
Overall, the idea of a Stratellite wireless network seem to be marketable in the sense that they would be more cost effective than satellites and cellular towers, and with the proper testing they potentially have the ability to turn the whole country in one giant hot spot. This is something that from judging by the popularity and use of “hotspots” the nation is ready for.