22-09-2008, 09:49 AM
Definition
Affordable bandwidth will be as essential to the Information Revolution in the21 st century as inexpensive power was to the Industrial Revolution in the 18 th and 19 th centuries. Today's global communications infrastructures of landlines, cellular towers, and satellites are inadequately equipped to support the increasing worldwide demand for faster, better, and less expensive service. At a time when conventional ground and satellite systems are facing increasing obstacles and spiraling costs, a low cost solution is being advocated.
This paper focuses on airborne platforms- airships, planes, helicopters or some hybrid solutions which could operate at stratospheric altitudes for significant periods of time, be low cost and be capable of carrying sizable multipurpose communications payloads. This report briefly presents an overview about the internal architecture of a High Altitude Aeronautical Platform and the various HAAPS projects.
High Altitude Aeronautical Platform Stations (HAAPS) is the name of a technology for providing wireless narrowband and broadband telecommunication services as well as broadcasting services with either airships or aircrafts. The HAAPS are operating at altitudes between 3 to 22 km. A HAPS shall be able to cover a service area of up to 1'000 km diameter, depending on the minimum elevation angle accepted from the user's location. The platforms may be airplanes or airships (essentially balloons) and may be manned or un-manned with autonomous operation coupled with remote control from the ground. While the term HAP may not have a rigid definition, we take it to mean a solar-powered and unmanned airplane or airship, capable of long endurance on-station -possibly several years.
Various types of platform options exist: SkyStation?, the Japanese Stratospheric Platform Project, the European Space Agency (ESA) and others suggest the use of airships/blimps/dirigibles. These will be stationed at 21km and are expected to remain aloft for about 5 years. Angel Technologies (HALO?), AeroVironment/ NASA (Helios) and the European Union (Heliplat) propose the use of high altitude long endurance aircraft. The aircraft are either engine or solar powered and are stationed at 16km (HALO) or 21km (Helios). Helios is expected to stay aloft for a minimum of 6 months whereas HALO will have 3 aircraft flying in 8- hour shifts. Platforms Wireless International is implementing a tethered aerostat situated at ~6km.
Definition
There are various applications that require a 3D world to be simulated as realistically as possible on a computer screen. These include 3D animations in games, movies and other real world simulations. It takes a lot of computing power to represent a 3D world due to the great amount of information that must be used to generate a realistic 3D world and the complex mathematical operations that must be used to project this 3D world onto a computer screen. In this situation, the processing time and bandwidth are at a premium due to large amounts of both computation and data.
The functional purpose of a GPU then, is to provide a separate dedicated graphics resources, including a graphics processor and memory, to relieve some of the burden off of the main system resources, namely the Central Processing Unit, Main Memory, and the System Bus, which would otherwise get saturated with graphical operations and I/O requests. The abstract goal of a GPU, however, is to enable a representation of a 3D world as realistically as possible. So these GPUs are designed to provide additional computational power that is customized specifically to perform these 3D tasks.
A Graphics Processing Unit (GPU) is a microprocessor that has been designed specifically for the processing of 3D graphics. The processor is built with integrated transform, lighting, triangle setup/clipping, and rendering engines, capable of handling millions of math-intensive processes per second. GPUs form the heart of modern graphics cards, relieving the CPU (central processing units) of much of the graphics processing load. GPUs allow products such as desktop PCs, portable computers, and game consoles to process real-time 3D graphics that only a few years ago were only available on high-end workstations.
Used primarily for 3-D applications, a graphics processing unit is a single-chip processor that creates lighting effects and transforms objects every time a 3D scene is redrawn. These are mathematically-intensive tasks, which otherwise, would put quite a strain on the CPU. Lifting this burden from the CPU frees up cycles that can be used for other jobs.
However, the GPU is not just for playing 3D-intense videogames or for those who create graphics (sometimes referred to as graphics rendering or content-creation) but is a crucial component that is critical to the PC's overall system speed. In order to fully appreciate the graphics card's role it must first be understood.
Many synonyms exist for Graphics Processing Unit in which the popular one being the graphics card .It's also known as a video card, video accelerator, video adapter, video board, graphics accelerator, or graphics adapter.
The first graphics cards, introduced in August of 1981 by IBM, were monochrome cards designated as Monochrome Display Adapters (MDAs). The displays that used these cards were typically text-only, with green or white text on a black background. Color for IBM-compatible computers appeared on the scene with the 4-color Hercules Graphics Card (HGC), followed by the 8-color Color Graphics Adapter (CGA) and 16-color Enhanced Graphics Adapter (EGA). During the same time, other computer manufacturers, such as Commodore, were introducing computers with built-in graphics adapters that could handle a varying number of colors.tions ux400. Perhaps the most interesting difence between VGA and the preceding formats is that VGA was analog, whereas lays had been digital up to that pGoinfrom digital to analog may seem like a step backward, but it actually provided the ability to vary the signal for more possible combinations than the strict on/off nature of digital.
