Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
D o p p l e r B a s e d M u l t i p l e A c c e s s The problem of flow control for little LEO satellite communication systems is studied. In
 

Summary: 1
D o p p l e r B a s e d M u l t i p l e A c c e s s
Abstract
The problem of flow control for little LEO satellite communication systems is studied. In
these systems the satellite functions as a ``bent pipe'' transponder for messaging between
small terminals and a command and data acquisition (CDA) earth station. A novel
scheme for averting traffic overflow on the inbound channel (from terminal to CDA),
which we call ``Doppler Based Multiple Access (DBMA)'', is introduced. In DBMA, the
CDA specifies a subset of the visibility footprint as a region of eligibility (ROE). Only
terminals located in the ROE are permitted to transmit. By varying the size and location
of the ROE, effective flow control on the inbound channel is achieved. The ROEs are
specified in terms of parameters of the Doppler frequency­shift versus time curve
observed at terminals on the outbound downlink channel (from satellite to terminal). The
effectiveness and elegance of DBMA protocol are illustrated through computer
simulations.
Key Words: LEO satellites, multiple access protocols, congestion avoidance, flow control, Doppler
estimation.
1 Introduction
That satellite communications continues to grow in importance is hardly news. What is noteworthy is the
continued evolution and refinement of distinct genres of satellite systems. At present, the great majority of

  

Source: Al-Dhahir, Naofal - Department of Electrical Engineering, University of Texas at Dallas

 

Collections: Engineering