Idle mode measurement
First Claim
1. A method of setting signal characteristics in a cellular telecommunications system in which cells are made available to a user terminal by more than one satellite concurrently, comprising:
- in an idle mode when no call is being made, making a plurality of cell reception measurements at a user terminal, said measurements corresponding to the quality of reception of channels transmitted over first and second communication paths via first and second satellites, respectively, the first and second satellites being in non-geosynchronous orbits;
on changing to dedicated mode, reporting information relating to the measurements made in the idle mode to a location remote from the user terminal;
using said measurements at said remote location as a basis for selecting one of the first and second communication paths for a calls; and
using said measurements at said remote location as a basis for setting initial characteristics of signals transmitted to the user terminal for the call to thereby permit communication between the user terminal and the selected one of the first and second satellites.
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Accused Products
Abstract
In a cellular satellite mobile telecommunication system, cell reception measurements for cell broadcast channels (BCCH) at a user terminal (UT 1) are made in an idle mode when no call is being made. At the commencement of a call, the measurement information (31, FIG. 8) relating to the measurement made in the idle mode is encoded onto a slow control channel (SACCH up) associated with a speech channel (TCH) for speech communication from the user terminal to a remote ground station (SAN 1) via a satellite (3a), and the power of the speech channel transmitted to the user terminal from the satellite, and from the UT to the satellite, for the call, is set in dependence upon the report. The reported data can also be used to determine whether to make a cell or satellite handover.
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Citations
12 Claims
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1. A method of setting signal characteristics in a cellular telecommunications system in which cells are made available to a user terminal by more than one satellite concurrently, comprising:
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in an idle mode when no call is being made, making a plurality of cell reception measurements at a user terminal, said measurements corresponding to the quality of reception of channels transmitted over first and second communication paths via first and second satellites, respectively, the first and second satellites being in non-geosynchronous orbits;
on changing to dedicated mode, reporting information relating to the measurements made in the idle mode to a location remote from the user terminal;
using said measurements at said remote location as a basis for selecting one of the first and second communication paths for a calls; and
using said measurements at said remote location as a basis for setting initial characteristics of signals transmitted to the user terminal for the call to thereby permit communication between the user terminal and the selected one of the first and second satellites. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A user terminal for use in a cellular telecommuncations system in which cells are made available to a user terminal by more than one satellite concurrently, comprising:
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receiver circuitry configured to make a plurality of cell reception measurements at the user terminal in an idle mode when no call is being made, said measurements corresponding to the quality of reception of channels transmitted over diverse communication paths via first and second satellites; and
transmitter circuitry operable on changing to dedicated mode, to report information relating to the measurements made in the idle mode to a location remote from the user terminal, for selecting one of the first and second satellites for a call via a selected one of the first and second satellites and for setting characteristics of signals transmitted to the user terminal for the call.
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8. A method of operating a subsystem for use in a cellular telecommunications system to communicate with remote user terminals, in which cells are made available to the user terminals by more than one satellite concurrently, comprising:
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receiving from a remote user terminal, a report of cell measurement information corresponding to a plurality of cell reception measurements relating to the quality of reception of channels transmitted over diverse communication paths via first and second satellites and made by the user terminal in an idle mode when no call is being made, the report being made to the subsystem prior to commencement of a call;
selecting one of the diverse communication paths via a selected one of the first and second satellites corresponding to the selected one of the diverse communication paths for the call in dependence on the report; and
setting characteristics of signals transmitted to the user terminal for a call in dependence on the report. - View Dependent Claims (9, 10)
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11. A subsystem for use in a cellular telecommunications system to communicate with remote user terminals in which cells are made available to the user terminals by more than one satellite concurrently, comprising:
receiver circuitry to receive, from a remote user terminal, a report of cell measurement information corresponding to a plurality of cell reception measurements relating to the quality of reception of channels transmitted over diverse communication paths via first and second satellites and made by the user terminal in an idle mode when no call is being made, the report being made to the subsystem prior to commencement of a call, and setting means to set characteristics of signals transmitted to the user terminal for a call and to select one of the diverse communication paths via either the first or second satellite corresponding to the selected one of the diverse communication paths for routing said signals in dependence on the report. - View Dependent Claims (12)
Specification