# US 5,706,283 A · Radio communication system in which base station transmits signal indicating whether or not message is valid to terminal stations

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- Number: US 5,706,283 A
- Document ID: US5706283A
- Status: Granted
- Kind: A
- Application number: 08/272,228
- Filed: 1994-07-08
- Granted: 1998-01-06
- Earliest claimed: 1993-07-16
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Akira Suzuki
- Web page: https://patentgrep.com/patent/US5706283A

## CPC

- H04W 52/0229: {where the received signal is a wanted signal}
- H04W 88/022: {Selective call receivers}
- Y02D 30/70: in wireless communication networks
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

A valid bit generator of a base station generates a valid bit to be disposed at or near the top of a message to be transmitted. The valid bit is set to be inactive if the message can be ignored, or active if the message cannot be ignored. Upon reception of this message, a valid bit detector at each terminal station judges whether the valid bit of the received message is inactive or active. If the valid bit is inactive, a message analyzing process is immediately stopped, whereas if it is active, the message is received and analyzed to the end thereof.

## Claims

### Claim 1

A radio communication system, comprising:
a base station;
a terminal station;
means provided in said base station for adding a valid bit in a message to be transmitted to said terminal station, setting said valid bit to be inactive if said message is to be ignored by said terminal station, setting said valid bit to be active if said message is not to be ignored by said terminal station, and transmitting said message, including said valid bit, to said terminal station, said message being constituted by a plurality of bits; and
means provided in said terminal station for receiving said message which includes said valid bit, judging whether said valid bit included in said received message is inactive or active, and processing said received message only if said included valid bit is active.

### Claim 2 (depends on 1)

A radio communication system according to claim 1, wherein:
said means provided in said base station includes means for repeating said valid bit to provide a train of valid bits which are included in the message that is transmitted, all of the bits in said train of valid bits being set to be inactive if said message is to be ignored by said terminal station and being set to be active if said message is not to be ignored by said terminal station, and
said means provided in said terminal station includes means for judging whether the number of active bits in the train of valid bits that is received by said terminal station is equal to, or larger than, half of the number of bits in the train of valid bits that was transmitted from said base station, said received message being processed only if the number of active bits is equal to, or larger than, half of the number of bits in the train of valid bits that was transmitted.

### Claim 3

A radio communication system in which a control channel is monitored dispersively and periodically only during a time called a slot, comprising;
a base station;
a terminal station;
means provided in said base station for inserting a valid bit and a plurality of messages in a slot assigned to the terminal station, setting said valid bit to be inactive if all said messages are to be ignored by said terminal station, setting said valid bit to be active if at least one of said messages is not to be ignored by said terminal station, and transmitting said valid bit and said plurality of messages to said terminal station during the assigned slot; and
means provided in said terminal station for receiving said valid bit and said plurality of messages during the assigned slot, judging whether said received valid bit is inactive or active, and processing said received messages only if said received valid bit is active.

### Claim 4 (depends on 3)

A radio communication system according to claim 3, wherein:
said means provided in said base station includes means for repeating said valid bit to provide a train of valid bits which are transmitted during the assigned slot along with said messages, all of the bits in said train of valid bits being set to be inactive if all of said messages are to be ignored by said terminal station and being set to be active if at least one message is not to be ignored by said terminal station, and
said means provided in said terminal station includes means for judging whether the number of active bits in the train of valid bits is equal to, or larger than, half of the number of bits in said train of valid bits transmitted from said base station, said received message being processed only if the number of active bits is equal to, or larger than, half of the number of bits in the train of valid bits that was transmitted.

### Claim 5

A terminal station for use with a base station which transmits a valid bit along with at least one message to the terminal station, the valid bit having either an active state or an inactive state, said terminal station comprising;
means for receiving the valid bit and the at least one message;
means for determining whether the state of the valid bit is active or inactive; and
processing means for processing the at least one message, the processing means including means for stopping the processing of the at least one message if the state of the valid bit is determined to be inactive.

### Claim 6 (depends on 5)

A terminal station according to claim 5, wherein the base station transmits the valid bit along with the at least one message during a time slot assigned to the terminal station, and wherein the terminal station further comprises set-up timer means for actuating the means for receiving during the assigned time slot.

### Claim 7

A terminal station for use with a base station which transmits a train of valid bits along with at least one message to the terminal station, each valid bit having either an active state or an inactive state and all of the valid bits in the transmitted train of valid bits having the same state, said terminal station comprising:
means for receiving the train of valid bits and the at least one message;
means for determining whether the number of active valid bits in the received train of valid bits is equal to or greater than a predetermined percentage of the number of valid bits in the transmitted train of valid bits; and
processing means for processing the at least one message, the processing means including means for stopping the processing of the at least one message if the number of active valid bits in the received train of valid bits is less than the predetermined percentage of the number of valid bits in the transmitted train of valid bits.

### Claim 8 (depends on 7)

A terminal station according to claim 7, wherein the predetermined percentage is 50%.

### Claim 9 (depends on 7)

A terminal station according to claim 7, wherein the base station transmits the train of valid bits along with the at least one message during a time slot assigned to the terminal station, and wherein the terminal station further comprises set-up timer means for actuating the means for receiving during the assigned time slot.

### Claim 10 (depends on 1)

A radio communication system according to claim 1, wherein said means provided in said terminal station comprises means for placing said terminal station in a power-saving standby state if said included valid bit is inactive.

### Claim 11 (depends on 3)

A radio communication system according to claim 3, wherein the assigned slot has a slot duration, and wherein said means provided in said terminal station comprises means for placing said terminal station in a power-saving standby state before the slot duration has elapsed if the received valid bit is inactive.

### Claim 12 (depends on 6)

A terminal station according to claim 6, wherein the time slot assigned to the terminal station has a slot duration, and wherein the means for stopping the processing comprises means for placing the terminal station in a power-saving standby state before the slot duration has elapsed if the state of the valid bit is determined to be inactive.

### Claim 13 (depends on 9)

A terminal station according to claim 9, wherein the time slot assigned to the terminal station has a slot duration, and wherein the means for stopping the processing comprises means for placing the terminal station in a power-saving standby state before the slot duration has elapsed if the number of active valid bits in the received train of valid bits is less than the predetermined percentage.

### Claim 14 (depends on 1)

A radio communication system according to claim 1, wherein:
said message comprises control data;
said means provided in said base station comprises means for transmitting said message on a control channel, without addressing said terminal device, during a time slot; and
wherein said means provided said terminal station comprises means for monitoring said time slot.

### Claim 15 (depends on 14)

A radio communication system according to claim 14, further comprising another terminal device, the another terminal device being provided with means for monitoring said time slot without being addressed, receiving said message which includes said valid bit, judging whether said valid bit included in said received message is inactive or active, and processing said received message only if said included valid but is active.

### Claim 16 (depends on 3)

A radio communication system according to claim 3, wherein:
said plurality of messages comprise control data; and
said means provided in said base station comprises means for transmitting said valid bit and said plurality of messages during the assigned slot without addressing said terminal station.

### Claim 17 (depends on 16)

A radio communication system according to claim 16, further comprising another terminal station, the another terminal station being provided with means for receiving said valid bit and said plurality of messages during the assigned slot without being addressed, judging whether said received valid bit is inactive or active, and processing said received message only if said received valid bit is active.

### Claim 18 (depends on 6)

A terminal station according to claim 6, wherein the at least one message comprises control data which the base station transmits on a control channel during the time slot without addressing the terminal station.

### Claim 19 (depends on 18)

A terminal station according to claim 18, wherein the time slot assigned to the terminal station is not assigned uniquely to the terminal station, and is instead commonly assigned to the terminal station and at least one further terminal station.

### Claim 20 (depends on 7)

A terminal station according to claim 7, wherein the at least one message comprises control data which the base station transmit on a control channel during the time slot without addressing the terminal station.

### Claim 21 (depends on 20)

A terminal station according to claim 20, wherein the time slot assigned to the terminal station is not assigned uniquely to the terminal station, and is instead commonly assigned to the terminal station and at least one further terminal station.