METHOD AND APPARATUS FOR BASE STATION TRANSMIT POWER ADJUSTMENT TO REDUCE POWER CONSUMPTION

• US 20160095067A1
• Filed: 08/28/2015
• Published: 03/31/2016
• Est. Priority Date: 09/25/2014
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: JURZAK, PAWEL, KUEHNER, NATHANAEL P., MROWIEC, ROBERT
• Granted Patent: US 10,356,722 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 3/46 Monitoring; Testing
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 88/12 Access point controller devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A process for adjusting base station transmit power to reduce power consumption in a wireless radio system, the method includes causing, by a radio controller, a message to be transmitted on a control channel in the wireless radio system proposing a transmit power reduction with respect to a traffic channel in the wireless radio system. Subsequently monitoring, by the radio controller, one or both of the control channel and the traffic channel for an indication from a mobile station affected by the proposed power reduction that the proposed power reduction is unacceptable. And modifying, by the radio controller, as a function of the presence or absence of the indication, the transmit power of the traffic channel.

Claims

1. A method for adjusting base station transmit power to reduce power consumption in a wireless radio system, the method comprising:

causing, by a radio controller, a message to be transmitted on a control channel in the wireless radio system proposing a transmit power reduction with respect to a traffic channel in the wireless radio system;

monitoring, by the radio controller, one or both of the control channel and the traffic channel for an indication from a mobile station affected by the proposed power reduction that the proposed power reduction is unacceptable; and

modifying, by the radio controller, as a function of the presence or absence of the indication, the transmit power of the traffic channel.

2. The method of claim 1, further comprising, responsive to detecting the indication during the monitoring:

causing, by the radio controller, a second message to be transmitted on the control channel proposing a second transmit power reduction on the traffic channel less than the first proposed transmit power reduction.

3. The method of claim 2, further comprising again monitoring, by the radio controller, one or both of the control channel and the traffic channel for an indication from a mobile station affected by the second proposed transmit power reduction that the second proposed transmit power reduction is unacceptable.

4. The method of claim 3, wherein the second proposed transmit power reduction is a function of a mobile station counter-proposed transmit power reduction received at the radio controller via one of the control channel and traffic channel in response to the transmission of the first proposed transmit power reduction.

5. The method of claim 1, wherein the control channel is transmitted at a first transmit power and the proposed transmit power reduction for the traffic channel sets a second transmit power of the traffic channel to less than the first transmit power.

6. The method of claim 5, wherein the first transmit power is a maximum transmit power of a base station that is broadcasting the control channel.

7. The method of claim 1, wherein the message specifies a window of time on one of the control channel and traffic channel for mobile stations to transmit the indication that the proposed transmit power reduction is unacceptable;

wherein the monitoring comprises monitoring for transmitted radio frequency (RF) energy above a threshold level during the specified window of time without decoding information represented by the RF energy; and

wherein the absence of the indication is a detected absence of transmitted RF energy during the specified window of time.

8. The method of claim 1, wherein the traffic channel is associated with a group of mobile stations assigned to the traffic channel, and wherein the mobile station affected by the proposed transmit power reduction is associated with the group.

9. The method of claim 1, further comprising:

causing, by the radio controller, a second message to be transmitted on the control channel in the wireless radio system proposing a second transmit power reduction with respect to a second traffic channel in the wireless radio system;

monitoring, by the radio controller, one or both of the control channel and the second traffic channel for an indication from a mobile station affected by the proposed second transmit power reduction that the proposed second transmit power reduction is unacceptable; and

modifying, by the radio controller, as a function of the presence or absence of the indication, the second transmit power of the second traffic channel.

10. The method of claim 1, wherein the message is an initial or periodically re-broadcast group call announcement associated with a call assigned to the traffic channel.

11. The method of claim 1, wherein the indication is absent and the transmit power of the traffic channel is reduced, the method further comprising:

subsequently receiving, at the radio control and from a mobile station via the control channel, a request to increase transmit power of the traffic channel, and responsively increasing the transmit power of the traffic channel.

12. A radio controller in a wireless radio system, the controller comprising:

a transceiver;

a data store; and

one or more processors configured to;

cause a message to be transmitted on a control channel in the wireless radio system proposing a transmit power reduction with respect to a traffic channel in the wireless radio system;

monitor one or both of the control channel and the traffic channel for an indication from a mobile station affected by the proposed power reduction that the proposed power reduction is unacceptable; and

modify, as a function of the presence or absence of the indication, the transmit power of the traffic channel.

13. The radio controller of claim 12, wherein the processor is further configured to, responsive to detecting the indication during the monitoring:

cause a second message to be transmitted on the control channel proposing a second transmit power reduction on the traffic channel less than the first proposed transmit power reduction.

14. The radio controller of claim 12, wherein the control channel is transmitted at a first transmit power and the proposed transmit power reduction for the traffic channel sets a second transmit power of the traffic channel to less than the first transmit power.

15. The radio controller of claim 12, wherein the message specifies a window of time on one of the control channel and traffic channel for mobile stations to transmit the indication that the proposed transmit power reduction is unacceptable;

wherein the monitoring comprises monitoring for transmitted radio frequency (RF) energy above a threshold level during the specified window of time without decoding information represented by the RF energy; and

wherein the absence of the indication is a detected absence of transmitted RF energy during the specified window of time.

16. The radio controller of claim 12, wherein the traffic channel is associated with a group of mobile stations assigned to the traffic channel, and wherein the mobile station affected by the proposed transmit power reduction is associated with the group.

17. A mobile station in a wireless radio system, the mobile station comprising:

a transceiver;

a memory storing computer readable instructions; and

one or more processors that, in response to executing the computer readable instructions, performs a set of functions comprising;

receiving, via the transceiver and a control channel in the wireless radio system, a message proposing a transmit power reduction on a traffic channel in the wireless radio system on which the mobile station is receiving or expects to receive communication information;

determining, as a function of a measured received signal strength indication (RSSI) of the control channel and a preconfigured or dynamically determined minimum receive signal strength, a link margin;

comparing the determined link margin to the proposed transmit power reduction, and responsive to determining that the proposed transmit power reduction is greater than the link margin, transmitting, via the transceiver, a signal indicative of the unacceptable nature of the proposed transmit power reduction on one of the control channel and the traffic channel.

18. The mobile station of claim 17, the set of functions further comprising:

detecting, via the transceiver and the control channel in the wireless radio system, a message identifying a group call of a group with which the mobile station is associated occurring or about to occur on a second traffic channel;

switching via the transceiver to the second traffic channel;

responsive to detecting an unacceptable signal level on the second traffic channel;

switching the transceiver back to the control channel and transmitting a request to increase the transmit power of the second traffic channel.

19. The mobile station of claim 17, the set of functions further comprising:

receiving, via the transceiver and the control channel in the wireless radio system, a second message proposing a second transmit power reduction with respect to the traffic channel in the wireless radio system on which the mobile station is receiving or expects to receive communication information, the second transmit power reduction being lower than the first transmit power reduction;

comparing the determined link margin to the proposed second transmit power reduction, and responsive to determining that the proposed second transmit power reduction is less than the link margin, refraining from transmitting, via the transceiver, the signal indicative of the unacceptable nature of the proposed second transmit power reduction on one of the control channel and the traffic channel.

20. The mobile station of claim 17, the set of functions further comprising:

continuing to monitor an RSSI of the traffic channel, and responsive to the RSSI falling below a predetermined threshold level, switching the transceiver back to the control channel and transmitting a request to increase the transmit power of the traffic channel.