Transmission control method of downgoing control signal in TDMA mobile communications system
First Claim
1. In a TDMA mobile communications system in which a mobile terminal is located within service areas provided by a plurality of base stations, each said base station independently transmitting a control signal of a predetermined radio frequency at first predetermined intervals, a transmission control method comprising the steps of:
- at said mobile terminal,a) synchronizing with a first control signal received from a first base station of said base stations to allocate a plurality of time slots according to said first control signal;
b) determining whether a radio wave of said predetermined radio frequency exists in each said time slot to generate radio condition information of said time slots;
c) transmitting said radio condition information to said first base station;
at said first base station,d) detecting a first time interval between adjacent time slots associated with said first base station and another base station during which said radio wave does not exist, on the basis of said radio condition information received from said mobile terminal; and
e) changing in transmission timing of said first control signal when said first time interval is smaller than a predetermined value, such that said first time interval becomes larger than said predetermined value.
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Accused Products
Abstract
In a method of controlling the transmission of a downgoing control signal, a mobile terminal detects the presence of radio wave of a downgoing control signal in each time slot in response to an inquiry signal received from a base station. The mobile terminal generates an answer signal indicating the time positions of radio waves received within a predetermined interval, and transmits the answer signal to the base apparatus. The base apparatus, receiving the radio condition answer signal, detects time differences between the downgoing control signal sent by the base apparatus itself and other downgoing control signals sent by other base apparatuses. If at least one time difference becomes lower than a predetermined threshold, the base apparatus changes the transmission timing of the downgoing control signal such that the time difference becomes larger than the threshold.
31 Citations
18 Claims
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1. In a TDMA mobile communications system in which a mobile terminal is located within service areas provided by a plurality of base stations, each said base station independently transmitting a control signal of a predetermined radio frequency at first predetermined intervals, a transmission control method comprising the steps of:
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at said mobile terminal, a) synchronizing with a first control signal received from a first base station of said base stations to allocate a plurality of time slots according to said first control signal; b) determining whether a radio wave of said predetermined radio frequency exists in each said time slot to generate radio condition information of said time slots; c) transmitting said radio condition information to said first base station; at said first base station, d) detecting a first time interval between adjacent time slots associated with said first base station and another base station during which said radio wave does not exist, on the basis of said radio condition information received from said mobile terminal; and e) changing in transmission timing of said first control signal when said first time interval is smaller than a predetermined value, such that said first time interval becomes larger than said predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In a TDMA mobile communications system in which a mobile terminal is located within service areas provided by a plurality of base stations, each said base station independently transmitting a control signal of a predetermined radio frequency at first predetermined intervals, a transmission control method comprising the steps of:
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at a first base station of said base stations, a) transmitting a first control signal to said mobile terminal at second predetermined intervals, said first control signal being a radio condition inquiry signal; at said mobile terminal, b) synchronizing with said radio condition inquiry signal received from said first base station to allocate a plurality of time slots; c) determining whether a radio wave of said predetermined radio frequency exists in each said time slot to generate radio condition information of said time slots; d) transmitting a radio condition answer signal including said radio condition information to said first base station; at said first base station, e) detecting a first time interval between adjacent time slots associated with said first base station and another base station during which said radio wave does not exist, on the basis of said radio condition information received from said mobile terminal; and f) changing in transmission timing of said control signal when said first time interval is smaller than a predetermined value, such that said first time interval becomes larger than said predetermined value. - View Dependent Claims (9, 10, 11)
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12. A TDMA mobile communications system in which a mobile terminal is located within service areas provided by a plurality of base stations, each said base station independently transmitting a control signal of a predetermined radio frequency at first predetermined intervals,
said mobile terminal comprising: -
synchronizing means for synchronizing with a first control signal received from a first base station of said base stations to allocate a plurality of time slots according to said first control signal; checking means for checking whether a radio wave of said predetermined radio frequency exists in each said time slot to generate radio condition information of said time slots; and transmitting means for transmitting said radio condition information to said first base station, and said first base station comprising; detecting means for detecting a first time interval between adjacent time slots associated with said first base station and another base station during which said radio wave does not exist, on the basis of said radio condition information received from said mobile terminal; and control means for changing in transmission timing of said first control signal when said first time interval is smaller than a predetermined value, such that said first time interval becomes larger than said predetermined value. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A TDMA mobile communications system in which a mobile terminal is located within service areas provided by a plurality of base stations, each said base station independently transmitting a control signal of a predetermined radio frequency at first predetermined intervals,
said mobile terminal comprising: -
synchronizing means for synchronizing with a radio condition inquiry signal received from a first base station of said base stations to allocate a plurality of time slots; checking means for checking whether a radio wave of said predetermined radio frequency exists in each said time slot to generate radio condition information of said time slots; and answer transmitting means for transmitting a radio condition answer signal including said radio condition information to said first base station, and said first base station comprising; inquiry means for transmitting a first control signal to said mobile terminal at second predetermined intervals, said first control signal being said radio condition inquiry signal; detecting means for detecting a first time interval between adjacent time slots associated with said first base station and another base station during which said radio wave does not exist, on the basis of said radio condition information received from said mobile terminal; and control means for changing in transmission timing of said control signal when said first time interval is smaller than a predetermined value, such that said first time interval becomes larger than said predetermined value.
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Specification