Loading...
Please wait, while we are loading the content...
Similar Documents
A robust signalling system for land mobile satellite services
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Wines, Marie Shmith, Gary Hart, Nick Irish, Dale |
| Copyright Year | 1989 |
| Description | Presented here is a signalling system optimized to ensure expedient call set-up for satellite telephony services in a land mobile environment. In a land mobile environment, the satellite to mobile link is subject to impairments from multipath and shadowing phenomena, which result in signal amplitude and phase variations. Multipath, caused by signal scattering and reflections, results in sufficient link margin to compensate for these variations. Direct signal attenuation caused by shadowing due to buildings and vegetation may result in attenuation values in excess of 10 dB and commonly up to 20 dB. It is not practical to provide a link with sufficient margin to enable communication when the signal is blocked. When a moving vehicle passes these obstacles, the link will experience rapid changes in signal strength due to shadowing. Using statistical models of attenuation as a function of distance travelled, a communication strategy has been defined for the land mobile environment. |
| File Size | 342928 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19890018546 |
| Archival Resource Key | ark:/13960/t05x7747c |
| Language | English |
| Publisher Date | 1989-03-01 |
| Access Restriction | Open |
| Subject Keyword | Communications And Radar Signal Fading Mobile Communication Systems Scattering Reception Diversity Vegetation Communication Satellites Telephony Signal Reception Signal Transmission Attenuation Signal Reflection Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
