Basestation methods and apparatus for supporting timing synchronization
First Claim
1. A method of operating a base station having a periodic downlink timing structure in which beacon time slots occur on a periodic basis in the downlink, each beacon time slot including a plurality of superslots, the superslots within a beacon slot being identifiable through the use of a superslot index, each superslot including a plurality of symbol transmission time periods, the method comprising:
- monitoring to detect the receipt of an access probe signal;
transmitting a response to the access probe signal, the response including information indicating at least one of;
i) an amount of an indicated main superslot timing offset correction, the amount of the main superslot timing offset correction being an integer multiple of a superslot time period;
ii) a superslot identifier indicating the position of a downlink superslot within a beacon slot during which the base station received the access probe signal to which the received response corresponds;
iii) an identifier that identifiers the communications device which transmitted the access probe signal to which the received response corresponds, and iv) an identifier that identifies the access probe to which the response being responding to.
3 Assignments
0 Petitions
Accused Products
Abstract
A wireless terminal using OFDM signaling supporting both terrestrial and satellite base station connectivity operates using conventional access probe signaling in a first mode of operation to establish a timing synchronized wireless link with a terrestrial base station. In a second mode of operation, used to establish a timing synchronized wireless link with a satellite base station, a slightly modified access protocol is employed. The round trip signaling time and timing ambiguity between a wireless terminal and a satellite base station is substantially greater than with a terrestrial base station. The modified access protocol uses coding of access probe signals to uniquely identify a superslot index within a beaconslot. The modified protocol uses multiple access probes with different timing offsets to further resolve timing ambiguity and allows the satellite base station access monitoring interval to remain small in duration. Terrestrial base station location/connection information is used to estimate initial timing.
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Citations
26 Claims
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1. A method of operating a base station having a periodic downlink timing structure in which beacon time slots occur on a periodic basis in the downlink, each beacon time slot including a plurality of superslots, the superslots within a beacon slot being identifiable through the use of a superslot index, each superslot including a plurality of symbol transmission time periods, the method comprising:
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monitoring to detect the receipt of an access probe signal;
transmitting a response to the access probe signal, the response including information indicating at least one of;
i) an amount of an indicated main superslot timing offset correction, the amount of the main superslot timing offset correction being an integer multiple of a superslot time period;
ii) a superslot identifier indicating the position of a downlink superslot within a beacon slot during which the base station received the access probe signal to which the received response corresponds;
iii) an identifier that identifiers the communications device which transmitted the access probe signal to which the received response corresponds, and iv) an identifier that identifies the access probe to which the response being responding to. - View Dependent Claims (2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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- 3. The method of 1, wherein said step of transmitting a response to the access probe signal includes transmitting the response in a downlink superslot having at a predetermined superslot time offset from the time the response was received.
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18. A base station using a periodic downlink timing structure in which beacon time slots occur on a periodic basis, each beacon time slot including a plurality of superslots, the superslots within a beacon slot being identifiable through the use of a superslot index, each superslot including a plurality of symbol transmission time periods, the base station comprising:
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a receiver module for receiving and detecting an access probe signal from a wireless terminal;
a transmitter module for transmitting, in response to the access probe signal, a response including information indicating at least one of;
i) an amount of an indicated main superslot timing offset correction, the amount of the main superslot timing offset correction being an integer multiple of a superslot time period;
ii) a superslot identifier indicating the position of a superslot within a beacon slot during which the base station received the access probe signal to which the received response corresponds;
iii) an identifier that identifiers the communications device which transmitted the access probe signal to which the received response corresponds, and iv) an identifier that identifies the access probe to which the response being responding to. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26)
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Specification