ADAPTIVE DATA RATE CONTROL FOR NARROWCAST NETWORKS
1 Assignment
0 Petitions
Accused Products
Abstract
A system to provide narrowcast communications uses adaptive data rate control to individual subscribers such that the effects of precipitation or other link conditions, which are not common to all subscribers, is mitigated. The invention takes advantage of the fact that the narrowcast data consist of packets which are individually addressed to specific subscribers, or groups of subscribers. The narrowcast data is communicated on a plurality of channels, each of potentially differing data rates. The subscribers are assigned a particular channel, based upon their link quality, to receive packets addressed to them. The lower data rate channel will be less affected by adverse link conditions and are hence assigned to subscribers most likely to incur adverse link conditions.
-
Citations
21 Claims
-
1. (canceled)
-
2. A hub terminal for communicating with a first subscriber terminal and a second subscriber terminal via a satellite, comprising:
-
a data source configured to generate a first data packet comprising a first address for the first subscriber terminal and a second data packet comprising a second address for the second subscriber terminal; a demultiplexer coupled to the data source and configured to switch the first data packet into a first carrier modulation circuit and the second data packet into a second carrier modulation circuit; the first carrier modulation circuit configured to provide modulation and coding for a first carrier signal for transmitting the first data packet to the satellite and the second carrier modulation circuit configured to provide modulation and coding for a second carrier signal for transmitting the second data packet to the satellite; a first gain control circuit coupled to the first carrier modulation circuit and configured to adjust signal level of the first carrier signal and a second gain control circuit coupled to the second carrier modulation circuit and configured to adjust signal level of the second carrier signal; and a first transponder coupled to the first gain control circuit and configured to transmit the first carrier signal to the satellite and a second transponder coupled to the second gain control circuit and configured to transmit the second carrier signal to the satellite. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for communicating with a first subscriber terminal and a second subscriber terminal via a satellite, comprising:
-
generating a first data packet comprising a first address for the first subscriber terminal and a second data packet comprising a second address for the second subscriber terminal; assigning the first data packet to a first carrier signal and the second data packet to a second carrier signal; modulating and coding the first carrier signal according to a first modulation and coding scheme and the second carrier signal according to a second modulation and coding scheme; adjusting gain of the first carrier signal and the second carrier signal; transmitting to the satellite, using a first transponder, the first carrier signal; and transmitting to the satellite, using a second transponder, the second carrier signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
-
Specification