Method and system for transmitting content to a plurality of users of a mobile communication network

• US 8,682,376 B2
• Filed: 06/08/2005
• Issued: 03/25/2014
• Est. Priority Date: 06/08/2005
• Status: Active Grant

• Current Assignee: Telecom Italia S.p.A.
• Original Assignee: Telecom Italia S.p.A.
• Inventors: Franceschini, Daniele, Guerrini, Claudio, Caretti, Marco
• Primary Examiner(s): TAYLOR, BARRY W
• Application Number:
  US11/921,558
• Publication Number:
  US 20090305712A1
• Time in Patent Office: 3,212 Days
• Field of Search: 455/522, 455/69, 370/318, 370/310.2
• US Class Current: 455/522
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/327 Power control of multicast channels
• CPC Class Codes: H04W 52/56 Detection of errors of TPC bits

Abstract

A method of distributing information content to at least two user equipments includes: setting up a common downlink channel common to the at least two user equipments; setting up at least two uplink channels, each uplink channel being dedicated to a respective one of the at least two user equipments; delivering the information content to the at least two user equipments over the common downlink channel; and controlling transmission powers related to the common downlink channel and the at least two uplink channels in a closed-loop fashion. The closed-loop fashion power control includes: receiving from the at least two user equipments common downlink channel quality indications over the respective dedicated uplink channels; adjusting a transmission power in respect to the common downlink channel based on the common downlink channel quality indications received from the user equipments; evaluating a channel quality with respect to each of the at least two dedicated uplink channels; and based on the evaluation, sending to the at least two user equipments a transmission power control command over the common downlink channel.

Claims

1. A method of distributing information content to at least two user equipments, comprising:

setting up a downlink channel common to the at least two user equipments;

setting up at least two uplink channels, each uplink channel being dedicated to a respective one of said at least two user equipments;

delivering the information content to said at least two user equipments over said common downlink channel; and

controlling transmission powers related to said common downlink channel and said at least two uplink channels in a closed-loop fashion, wherein said controlling transmission powers in a closed-loop fashion comprises;

receiving from the at least two user equipments common downlink channel quality indications over the respective dedicated uplink channels;

adjusting a transmission power with respect to said common downlink channel based on the common downlink channel quality indications received from the user equipments;

evaluating a channel quality with respect to each of said at least two dedicated uplink channels, wherein evaluating a channel quality further comprises;

defining a time window;

for each one of the at least two dedicated uplink channels, obtaining at least two uplink channel quality indications temporally separated within said time window, wherein said uplink channel quality indications are obtained by comparison with a respective uplink channel quality threshold;

for each one of the at least two dedicated uplink channels, obtaining an average uplink channel quality indication from said at least two temporally separated uplink channel quality indications; and

obtaining an overall uplink channel quality based on the average uplink channel quality indications with respect to the at least two dedicated uplink channels; and

based on said evaluation, sending to the at least two user equipments a transmission power control command over the common downlink channel.

2. The method according to claim 1, wherein said adjusting a transmission power with respect to said common downlink channel based on the common downlink channel quality indications received from the user equipments comprises performing a statistical analysis of the common downlink channel quality indications received from the at least two user equipments.

3. The method according to claim 2, wherein said performing the statistical analysis comprises:

increasing the transmission power with respect to the common downlink channel in case a number of received channel quality indications indicating a channel quality below a prescribed target quality exceeds a predetermined first threshold number of received channel quality indications.

4. The method according to claim 3, wherein said performing the statistical analysis comprises:

decreasing the transmission power with respect to the common downlink channel in case a number of received channel quality indications indicating a channel quality higher than or equal to a prescribed target quality exceeds a predetermined second threshold number of received channel quality indications.

5. The method according to claim 4, wherein said first threshold or said second threshold number of received channel quality indications are dependent on an overall number of said at least two user equipments.

6. The method according to claim 1, wherein said evaluating a channel quality with respect to each of said at least two dedicated uplink channels comprises establishing an overall uplink channel quality based on the evaluated channel qualities of the at least two dedicated uplink channels.

7. The method according to claim 1, wherein said transmission power control command sent to the at least two user equipments over the common downlink channel is commonly received by the at least two user equipments and causes the at least two user equipments to vary in a same way as transmission power of the respective dedicated uplink channels.

8. The method according to claim 1, wherein said sending to the at least two user equipments a transmission power control command over the common downlink channel, based on said evaluation, comprises:

ascertaining whether an overall interference power associated with said dedicated uplink channels exceeds a predetermined maximum interference power, and

in the affirmative case, sending to the at least two user equipments a transmission power decrease command, adapted to instruct the at least two user equipments to decrease a transmission power with respect to the associated dedicated uplink channels.

9. The method according to claim 1, wherein said sending to the at least two user equipments a transmission power control command over the common downlink channel, based on the said evaluation, further comprises:

ascertaining whether at least one of said at least two dedicated uplink channels has an associated uplink channel quality lower than a predetermined minimum uplink channel quality, and

in the affirmative case, sending to the at least two user equipments, a transmission power increase command, adapted to instruct the at least two user equipments to increase a transmission power with respect to the associated dedicated uplink channels.

10. The method according to claim 1, wherein said sending to the at least two user equipments a transmission power control command over the common downlink channel, based on said evaluation, further comprises:

ascertaining whether an overall number of dedicated uplink channels, among said at least two dedicated uplink channels, having an associated uplink channel quality exceeding said predetermined minimum uplink channel quality exceeds a predetermined threshold number of dedicated uplink channels, and

in the affirmative case, sending to the at least two user equipments said transmission power decrease command.

11. The method according to claim 10, wherein said threshold number of dedicated uplink channels depends on an overall number of said at least two user equipments.

12. The method according to claim 1, wherein said obtaining an average uplink channel quality indication comprises:

calculating a number of temporally-separated uplink channel quality indications indicating that the uplink channel quality is higher than or equal to said uplink channel quality threshold;

ascertaining whether said number of temporally-separated uplink channel quality indications exceeds a predetermined first threshold number of temporally-separated uplink channel quality indications; and

in the affirmative case, having said average uplink channel quality indication indicate that the uplink channel quality is higher than or equal to said uplink channel quality threshold.

13. The method according to claim 12, wherein said obtaining an average uplink channel quality indication further comprises:

ascertaining whether said number of temporally-separated uplink channel quality indications does not exceed a predetermined second threshold number of temporally-separated uplink channel quality indications; and

in the affirmative case, having said average uplink channel quality indication indicate that the uplink channel quality is lower than said uplink channel quality threshold.

14. The method according to claim 12, wherein said obtaining an average uplink channel quality indication further comprises:

having said average uplink channel quality indication indicate that the uplink channel quality is higher than or equal to said uplink channel quality threshold in case a number of more recent temporally-separated uplink channel quality indications indicating that the uplink channel quality is higher than or equal to said uplink channel quality threshold exceeds a predetermined third threshold number of temporally-separated uplink channel quality indications.

15. A wireless communications network comprising at least one radio transceiver station having an associated network cell and adapted to enable radio communications with user equipments located in the network cell, wherein the radio transceiver station is adapted to:

set up a common downlink channel with respect to at least two user equipments located in the network cell;

set up at least two dedicated uplink channels, each dedicated uplink channel being dedicated to a respective one of said at least two user equipments;

deliver an information content to said at least two user equipments over said common downlink channel;

receive from the at least two user equipments common downlink channel quality indications over the respective dedicated uplink channels;

adjust a transmission power with respect to said common downlink channel based on the common downlink channel quality indications received from the user equipments;

evaluate a channel quality related to each of said at least two dedicated uplink channels,

based on said evaluation, send to the at least two user equipments a transmission power control command over the common downlink channel,

define a time window;

for each one of the at least two dedicated uplink channels, obtain at least two uplink channel quality indications temporally-separated within said time window, wherein said uplink channel quality indications are obtained by comparison with a respective uplink channel quality threshold;

for each one of the at least two dedicated uplink channels, obtain an average uplink channel quality indication from said at least two temporally-separated uplink channel quality indications; and

obtain an overall uplink channel quality based on the average uplink channel quality indications with respect to the at least two dedicated uplink channels.

16. The wireless communications network according to claim 15, wherein said radio transceiver station is adapted to adjust the transmission power with respect to said common downlink channel based on a statistical analysis of the common downlink channel quality indications received from the at least two user equipments.

17. The wireless communications network according to claim 16, wherein said radio transceiver station is adapted to:

increase the transmission power with respect to the common downlink channel in case a number of received channel quality indications indicating a channel quality below a prescribed target quality exceeds a predetermined first threshold number of received channel quality indications.

18. The wireless communications network according to claim 17, wherein the radio transceiver station is adapted to:

decrease the transmission power with respect to the common downlink channel in case a number of received channel quality indications indicating a channel quality higher than or equal to a prescribed target quality exceeds a predetermined second threshold number of received channel quality indications.

19. The wireless communications network according to claim 18, wherein said first threshold or said second threshold are dependent on an overall number of said at least two user equipments.

20. The wireless communications network according to claim 15, wherein the radio transceiver station is adapted to establish an overall uplink channel quality based on the evaluated channel qualities of the at least two dedicated uplink channels.

21. The wireless communications network according to claim 15, wherein said transmission power control command sent to the at least two user equipments over the common downlink channel is commonly received by the at least two user equipments and causes the at least two user equipments to vary in a same way as transmission power of the respective dedicated uplink channels.

22. The wireless communications network according to claim 15, wherein the at least one radio transceiver station is adapted to:

ascertain whether an overall interference power associated with said dedicated uplink channels exceeds a predetermined maximum interference power, and

in the affirmative case, send to the at least two user equipments a transmission power decrease command, adapted to instruct the at least two user equipments to decrease a transmission power with respect to the associated dedicated uplink channels.

23. The wireless communications network according to claim 15, wherein the radio transceiver station is adapted to:

ascertain whether at least one of said at least two dedicated uplink channels has an associated uplink channel quality lower than a predetermined minimum uplink channel quality, and

in the affirmative case, send to the at least two user equipments a transmission power increase command, adapted to instruct the at least two user equipments to increase a transmission power with respect to the associated dedicated uplink channels.

24. The wireless communications network according to claim 15, wherein the radio transceiver station is adapted to:

ascertain whether an overall number of dedicated uplink channels, among said at least two dedicated uplink channels, having an associated uplink channel quality, exceeding said predetermined minimum uplink channel quality exceeds a predetermined threshold number of dedicated uplink channels, and

in the affirmative case, send to the at least two user equipments said transmission power decrease command.

25. The wireless communications network according to claim 24, wherein said threshold number of dedicated uplink channels depends on an overall number of said at least two user equipments.

26. The wireless communications network according to claim 15, wherein the radio transceiver station is adapted to:

calculate a number of temporally-separated uplink channel quality indications indicating that the uplink channel quality is higher than or equal to said uplink channel quality threshold;

ascertain whether said number of temporally-separated uplink channel quality indications exceeds a predetermined first threshold number of temporally-separated uplink channel quality indications; and

in the affirmative case, have said average uplink channel quality indication indicate that the uplink channel quality is higher than or equal to said uplink channel quality threshold.

27. The wireless communications network according to claim 26, wherein the radio transceiver station is adapted to:

ascertain whether said number of temporally-separated uplink channel quality indications does not exceed a predetermined second threshold number of temporally-separated uplink channel quality indications; and

in the affirmative case, have said average uplink channel quality indication indicate that the uplink channel quality is lower than said uplink channel quality threshold.

28. The wireless communications network according to claim 26, wherein the radio transceiver station is adapted to:

have said average uplink channel quality indication indicate that the uplink channel quality is higher than or equal to said uplink channel quality threshold in case a number of more recent temporally-separated uplink channel quality indications indicating that the uplink channel quality is higher than or equal to said uplink channel quality threshold exceeds a predetermined third threshold number of temporally-separated uplink channel quality indications.