Method and device for channel contention and data transmission for packet-switched subscriber units in a communication system
First Claim
1. A method for providing uplink contention and data transmission for single-slot packet-switched subscriber units in a time division multiple access system, comprising the steps of:
- 1A) selecting, by a subscriber unit, an uplink time slot in a TDMA frame;
1B) determining, on the corresponding time slot of the downlink channel, whether the selected uplink time slot is available for contention, and where the uplink time slot is available, sending a header segment in the selected uplink time slot; and
where the uplink time slot is in use, initiating a random delay before returning to step 1A;
1C) determining, on the same numbered downlink time slot of the next TDMA frame, whether the selected uplink time slot is still available, and where the selected uplink time slot is unavailable, initiating a random delay before returning to step 1A;
where the selected time slot is available, proceeding to step 1D;
1D) determining, on the same numbered downlink time slot of the next TDMA frame, whether the subscriber unit has gained access to the uplink channel, and where the subscriber unit has gained access to the uplink channel, transmitting the packet on the selected uplink time slot;
where the subscriber unit fails to gain access to the uplink channel, initiating a random delay before returning to step 1A.
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Accused Products
Abstract
The present invention provides a method (400, 500, 600, 700, 800, 900, 1000) and device (1100, 1200, 1300) for contention for channel access to single-slot subscriber units that are capable of transmitting and receiving data on one time slot per TDMA frame, allowing contention for channel access on any one of the available packet time slots and transmission on the time slot where contention is won. Thus, the present invention eliminates a requirement for a subscriber unit to be assigned to a particular time slot for contention, thereby eliminating the problem of performing load balancing on the time slots.
64 Citations
21 Claims
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1. A method for providing uplink contention and data transmission for single-slot packet-switched subscriber units in a time division multiple access system, comprising the steps of:
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1A) selecting, by a subscriber unit, an uplink time slot in a TDMA frame; 1B) determining, on the corresponding time slot of the downlink channel, whether the selected uplink time slot is available for contention, and where the uplink time slot is available, sending a header segment in the selected uplink time slot; and
where the uplink time slot is in use, initiating a random delay before returning to step 1A;1C) determining, on the same numbered downlink time slot of the next TDMA frame, whether the selected uplink time slot is still available, and where the selected uplink time slot is unavailable, initiating a random delay before returning to step 1A;
where the selected time slot is available, proceeding to step 1D;1D) determining, on the same numbered downlink time slot of the next TDMA frame, whether the subscriber unit has gained access to the uplink channel, and where the subscriber unit has gained access to the uplink channel, transmitting the packet on the selected uplink time slot;
where the subscriber unit fails to gain access to the uplink channel, initiating a random delay before returning to step 1A. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A microprocessor in a subscriber unit directed by a computer program to provide contention and data transmission for single-slot packet-switched subscriber units in a time division multiple access system, wherein the computer program comprises the steps of:
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7A) selecting, by a subscriber unit, an uplink time slot in a TDMA frame; 7B) determining, on the corresponding time slot of the downlink channel, whether the selected uplink time slot is available for contention, and where the uplink time slot is available, sending a header segment in the selected uplink time slot; and
where the uplink time slot is in use, initiating a random delay before returning to step 7A;7C) determining, on the same numbered downlink time slot of the next TDMA frame, whether the selected uplink time slot is still available, and where the selected uplink time slot is unavailable, initiating a random delay before returning to step 7A;
where the selected time slot is available, proceeding to step 7D;7D) determining, on the same numbered downlink time slot of the next TDMA frame, whether the subscriber unit has gained access to the uplink channel, and where the subscriber unit has gained access to the uplink channel, transmitting the packet on the selected uplink time slot;
where the subscriber unit fails to gain access to the uplink channel, initiating a random delay before returning to step 7A. - View Dependent Claims (8, 9, 10, 11)
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12. A method for using a base site to provide uplink contention and data transmission for single-slot packet-switched subscriber units in a time division multiple access system, comprising the steps of:
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12A) for each packet time slot of an uplink channel, broadcasting a status of the time slot on a corresponding downlink time slot; 12B) receiving and decoding at least a header segment from the subscriber unit(s); 12C) where the header segment(s) is unsuccessfully decoded, maintaining the status of the time slot and returning to step 12A, and where the header segment is successfully decoded, determining whether the time slot is available for assignment to the subscriber unit that sent the header segment;
where the time slot is unavailable, maintaining the status of the time slot and returning to step 12A, and where the time slot is available, updating the status of the time slot to indicate that the uplink time slot is busy and which subscriber unit has gained access to the time slot and proceeding to step 12D;12D) for each uplink packet time slot, broadcasting the status of the time slot on the corresponding downlink time slot. - View Dependent Claims (13, 14, 15, 16)
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17. A microprocessor in a base site directed by a computer program to provide uplink contention and data transmission for single-slot packet-switched subscriber units in a time division multiple access system, wherein the computer program comprises the steps of:
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17A) for each packet time slot of an uplink channel, broadcasting a status of the time slot on a corresponding downlink time slot; 17B) receiving and decoding at least a header segment from the subscriber unit(s); 17C) where the header segment(s) is unsuccessfully decoded, maintaining the status of the time slot and returning to step 17A, and where the header segment is successfully decoded, determining whether the time slot is available for assignment to the subscriber unit that sent the header segment;
where the time slot is unavailable, maintaining the status of the time slot and returning to step 17A, and where the time slot is available, updating the status of the time slot to indicate that the uplink time slot is busy and which subscriber unit has gained access to the time slot and proceeding to step 17D;17D) for each uplink packet time slot, broadcasting the status of the time slot on the corresponding downlink time slot. - View Dependent Claims (18, 19, 20)
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21. A base site for providing contention function and data transmission between a plurality subscriber units and the base site control unit in a TDMA system, comprising:
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a radio frequency receiver and demodulator block for converting the radio signal into digital data and for decoding the received data; a modulator and radio frequency transmitter block for encoding the data to be transmitted and for converting the encoded data into radio signal; and a plurality of coupled uplink-downlink processing units wherein each of the uplink processing units comprises; 21A) a first state machine for, upon receiving an uplink segment, updating and storing a busy/idle status of the current time slot and a resolution of the decoding of the received segment, 21B) a D-latch logic, coupled to the state machine, for storing a random number received from a subscriber unit; 21C) a counter, coupled to the D-latch and the first state machine, for setting the busy/idle status of the time slot to idle when a predetermined number of consecutive erroneous segments has been detected; and wherein the downlink processing unit comprises; 21D) a second state machine, coupled to a counter, for detecting and storing a traffic type of a time slot; 21E) a logic unit, coupled to the second state machine, for inserting a channel status which includes the busy/idle status of an uplink time slot, the resolution of the decoding of the previously received segment, and the received random number, into a slow channel field of the segment transmitted in the corresponding downlink time slot.
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Specification