Method and system for detecting discontinuous transmission mode

• US 6,370,392 B1
• Filed: 06/14/2000
• Issued: 04/09/2002
• Est. Priority Date: 09/13/1999
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Li, Jun, Wang, Chung-Ching
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): Green, Miguel D.
• Application Number:
  US09/594,064
• Time in Patent Office: 664 Days
• Field of Search: 455/13.4, 455/436, 455/522, 455/68, 455/69, 455/70, 455/701, 455/702, 455/703, 370/321, 370/329, 370/330, 370/331, 370/335, 370/337, 370/342, 370/345, 370/347, 370/468, 704/215, 704/270, 375/132, 375/216, 375/219, 375/295, 375/299, 375/316, 375/341, 375/342, 375/346, 375/347, 375/349
• US Class Current: 455/522
• CPC Class Codes: H04W 52/44 in connection with interruption of transmission
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

Various methods for effectively detecting the discontinuous transmission (DTX) mode are provided both from the physical layer perspective and from the medium access layer (MAC) perspective. The DTX mode transmission on reverse supplemental channels is detected by comparing a transmitted and a received power ratio of a pilot channel and a supplemental channel. For a reverse link communication, the DTX mode transmission is detected on dedicated control channels. The DTX mode transmission on a forward link supplemental channel can also be detected by monitoring both the transmitted and received power ratios of a primary power control channel and the supplemental channel. As an alternative to or in combination with the above mentioned methods, in order to monitor the DTX mode, a new network parameter is introduced which requires a change in the IS-2000-3 standard. This parameter acts as an indicator signaling to a receiver, from the MAC layer, that the transmitter has entered into the DTX mode.

Claims

1. A method for detecting a discontinuous transmission mode of a control channel transmitted between a mobile unit and a transmitter station in a telecommunications network, the method comprising:

obtaining a transmitted power strength ratio between the control channel and a reference channel;

determining a threshold value based on the transmitted power strength ratio;

monitoring a received power strength of the reference channel;

monitoring a received power strength of the control channel;

obtaining a received power strength ratio between the reference channel and the control channel; and

detecting the discontinuous transmission mode of the control channel by identifying an abrupt change in the received power strength ratio that crosses the threshold value.

2. The method of claim 1 wherein the transmitted power strength ratio is identified based on a series of pre-negotiated parameters.

3. The method of claim 2 wherein the pre-negotiated parameters includes RLGAIM_SCH_PILOT, RLGAIN_COMMOM_PILOT, RL_GAIN_ADJ.

4. The method of claim 1 wherein the control channel is a supplemental channel in a wide band code division multiple access network.

5. The method of claim 1 wherein the control channel is a dedicated control channel.

6. The method of claim 1 wherein the reference channel is a user-specific pilot channel on a reverse link.

7. The method of claim 1 wherein the reference channel is a power control sub-channel.

8. A method for detecting a discontinuous transmission mode of a control channel on a forward link transmitted from a transmitter station to a mobile unit in a telecommunication network, the method comprising the steps of:

obtaining a transmitted power strength ratio between the control channel and a power control sub-channel;

determining a threshold value based on the transmitted power strength ratio;

monitoring a received power strength of the power control sub-channel;

monitoring a received power strength of the control channel;

obtaining a received power strength ratio between the control channel and the power control sub-channel based on the received power strength of both the power control sub-channel and the control channel; and

detecting the discontinuous transmission mode of the control channel by discovering an abrupt change in the received power strength ratio that crosses the threshold value.

9. The method of claim 8 wherein the control channel is a supplemental control channel.

10. The method of claim 8 wherein the power control sub-channel is embedded in a primary power control channel.

11. The method of claim 10 wherein the primary power control channel is a fundamental channel.

12. The method of claim 10 wherein the primary power control channel is a dedicated control channel.

13. The method of claim 8 wherein the transmitted power strength ratio is identified based on a series of pre-negotiated parameters.

14. The method of claim 8 further includes the step of monitoring, by the mobile unit, a change of the transmitted power strength ratio due to a handoff condition.

15. The method of claim 14 wherein the mobile unit obtains a new threshold value based on a new transmitted power strength ratio between the control channel and the changed power control sub-channel due to the handoff.

16. A method for detecting a discontinuous transmission mode of a control channel on a reverse link transmitted from a mobile unit to a transmitter station in a telecommunication network, the method comprising the steps of:

obtaining a transmitted power strength ratio between the control channel and a pilot channel;

determining a threshold value based on the transmitted power strength ratio;

monitoring a received power strength of the pilot channel;

monitoring a received power strength of the control channel;

obtaining a received power strength ratio between the pilot channel and the control channel; and

determining the discontinuous transmission mode of the control channel by detecting a change in the received power strength ratio, as compared to the threshold value.

17. The method of claim 16 wherein the transmitted power strength ratio is identified based on a series of pre-negotiated parameters.

18. The method of claim 17 wherein the pre-negotiated parameters includes RLGAIM_SCH_PILOT, RLGAIN_COMMOM_PILOT, RL_GAIN_ADJ.

19. The method of claim 16 wherein the control channel is a supplemental channel in a wide band code division multiple access network.

20. The method of claim 16 wherein the control channel is a dedicated control channel.