NDLI: Communications to high latitudes using a commercial low Earth orbit satellite system

Content Provider	IEEE Xplore Digital Library
Author	Geaghan, B.S. Yuan, R.L.
Copyright Year	1990
Description	Author affiliation: Appl. Phys. Lab., Johns Hopkins Univ., Laurel, MD, USA (Geaghan, B.S.)
Abstract	Low Earth orbit (LEO) satellite communications systems could be deployed providing voice, data, facsimile and paging services to mobile users in many regions of the world. The LEO systems are expected to be used by the Department of Defense (DoD). The DoD will be able to use these systems for other applications that take advantage of the special features resulting from the LEO configuration, such as global connectivity and small mobile terminal size. We consider the ability of a LEO system to support communications to mobile terminals in the high latitudes. The study is based upon the IRIDIUM system, which will provide continuous polar coverage to commercial users. The two key criteria for assessing the ability of the LEO system to support high latitude missions are detectability of the radio frequency (RF) transmissions of the mobile terminal and communications availability. Detectability is critical because there are not expected to be many IRIDIUM users in the high latitudes. Detecting a high latitude user implies some degree of automatic identification, whereas detection at a lower latitude must be followed by some identification process to discriminate between many users. To decrease the detectability of the mobile unit RF emissions, it is assumed that the mobile terminal antenna is modified to reduce low elevation angle RF emissions. Therefore, the impact on detectability, as well as connectivity, when using a modified mobile terminal antenna is examined. After a description of the mobile terminal RF characteristics, the detection and connectivity analyses are presented.
Starting Page	407
Ending Page	415
File Size	687110
Page Count	9
File Format	PDF
ISBN	0780336585
DOI	10.1109/TCC.1996.561110
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	1996-04-30
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Low earth orbit satellites Artificial satellites Radio frequency Mobile antennas Satellite broadcasting Mobile communication Time division multiple access Telephone sets Satellite communication Radiofrequency identification
Content Type	Text
Resource Type	Article

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