Cell On-Off procedure for dual connectivity
Dynamic cell mode indication and reporting channel state information for dormant cells in a dual connectivity carrier aggregation environment. UEs may be configured for carrier aggregation of cells associated with non-collocated eNBs, which may include a master eNB (MeNB) and one or more secondary eNBs (SeNB), each supporting multiple carrier frequencies. Indicators of cell mode for secondary cells of the MeNB or SeNB are periodically sent using a broadcast mechanism and may configure active or dormant sub-periods within the indicated periods. The indicators may be transmitted by a primary cell for the MeNB or special secondary cell for the SeNB. Alternatively, the indicators may be transmitted by the secondary cell. When CSI measurements occur for a dormant cell, the UE may report CSI for the dormant periods, suppress CSI reporting for the dormant periods, or report some types of CSI and not others for the dormant periods.
1. A method of wireless communications, comprising:
identifying a multiple carrier configuration, the multiple carrier configuration including a first carrier group and a second carrier group,
the first carrier group being associated with a first base station and including a primary carrier only or the primary carrier and a first set of secondary carriers, and
the second carrier group being associated with a second base station and including a second set of secondary carriers, wherein one or more secondary carriers of the first set of secondary carriers or the second set of secondary carriers aperiodically transition between being dormant and non-dormant;
monitoring the one or more secondary carriers for a cell mode indicator indicating that a secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant;
determining that a first secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant based on a received cell mode indicator;
determining that a second secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is aperiodically dormant based on an absence of detecting information related to dormancy over the one or more secondary carriers during the monitoring; and
transmitting a channel feedback report for the one or more secondary carriers while the first and second secondary carriers are dormant, wherein the channel feedback report comprises channel interference feedback that is based on measurements of resources of the one or more secondary carriers while the first and second secondary carriers are dormant and channel quality feedback that is based on channel measurements of the one or more secondary carriers from a previous non-dormant period of the first and second secondary carriers.
2. The method of claim 1 , wherein the monitoring comprises:
monitoring the one or more secondary carriers from the first carrier group for cell mode indicators associated with the one or more secondary carriers of the first set of secondary carriers.
3. The method of claim 1 , wherein
the second carrier group comprises a special secondary carrier, and
wherein the monitoring comprises monitoring the special secondary carrier for cell mode indicators associated with the one or more secondary carriers of the second set of secondary carriers.
4. The method of claim 1 , wherein
the second carrier group comprises a special secondary carrier, and
wherein the monitoring comprises monitoring the one or more secondary carriers of the second set of secondary carriers for cell mode indicators associated with the one or more secondary carriers of the second set of secondary carriers.
5. The method of claim 1 , wherein the monitoring comprises monitoring one or more search spaces of at least a first carrier of the first carrier group and at least a second carrier of the second carrier group at predefined time intervals for downlink control information (DCI) comprising the indications of cell dormancy.
6. The method of claim 1 , wherein monitoring indications of cell dormancy for the multiple carrier configuration is based on activation states of secondary carriers of the first and second sets of secondary carriers.
7. The method of claim 1 , further comprising:
receiving an indication of cell dormancy associated with the first secondary carrier, and
wherein determining that the first secondary carrier is dormant comprises determining the first secondary carrier is dormant for a predetermined period of time.
8. The method of claim 1 , further comprising:
receiving an indication of cell dormancy associated with the first secondary carrier, and
wherein determining that the first secondary carrier is dormant comprises determining the first secondary carrier is dormant until a next cell dormancy indication is received.
9. A method of wireless communications, comprising:
determining, at a UE, a multiple carrier configuration including a first carrier group and a second carrier group,
the first carrier group being associated with a first base station and including a primary carrier only or the primary carrier and a first set of secondary carriers, and
the second carrier group being associated with a second base station and including a second set of secondary carriers, wherein one or more secondary carriers from the first set of secondary carriers or the second set of secondary carriers aperiodically transitions between being dormant and non-dormant;
monitoring the one or more secondary carriers for a cell mode indicator indicating that a secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant;
determining that a first secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant based on a received cell mode indicator;
determining that a second secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is aperiodically dormant based at least in part on detecting an aperiodic transition between being non-dormant and being dormant from an absence of information related to dormancy for the second secondary carrier;
determining a channel state information (CSI) reporting configuration for the first and second secondary carriers based at least in part on the determining that the first and second secondary carriers are dormant; and
performing CSI reporting according to the CSI reporting configuration, wherein the CSI reporting configuration comprises a first antenna port configuration for reporting CSI when the first and second secondary carriers are dormant and a second antenna port configuration for reporting CSI when the first and second secondary carriers are non-dormant, the first antenna port configuration being different than the second antenna port configuration.
10. The method of claim 9 , wherein performing CSI reporting further comprises:
determining whether the first and second secondary carriers are associated with the first base station or the second base station; and
performing CSI reporting for the first and second secondary carriers to the first base station or to the second base station based on the determined association and according to the CSI reporting configuration.
11. The method of claim 9 , wherein the first type of CSI comprises periodic CSI reporting and the second type of CSI comprises aperiodic CSI reporting.
12. The method of claim 9 , wherein the CSI reporting configuration further comprises averaging the channel measurements from at least one time period.
13. The method of claim 9 , further comprising:
determining a CSI reference signal (CSI-RS) measurement configuration for the at least one secondary carrier; and
performing CSI-RS measurements for the first and second secondary carriers according to the CSI-RS measurement configuration,
wherein performing CSI reporting is based on the CSI-RS measurements and the determined CSI reporting configuration.
14. The method of claim 13 , wherein performing CSI reporting comprises reporting one or more of channel measurements of the first and second secondary carriers, interference measurements of the first and second secondary carriers, or a combination thereof.
15. An apparatus for wireless communications, comprising:
means for identifying a multiple carrier configuration, the multiple carrier configuration comprising a first carrier group and a second carrier group,
the first carrier group being associated with a first base station and including a primary carrier only or the primary carrier and a first set of secondary carriers, and
the second carrier group being associated with a second base station and including a second set of secondary carriers, wherein one or more secondary carriers of the first set of secondary carriers or the second set of secondary carriers aperiodic ally transition between being dormant and non-dormant;
means for monitoring the one or more secondary carriers for a cell mode indicator indicating that a secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant;
means for determining that a first secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant based on a received cell mode indicator;
means for determining that a second secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is aperiodically dormant based on an absence of detecting information related to dormancy over the one or more secondary carriers during the monitoring; and
means for transmitting a channel feedback report for the one or more secondary carriers while the first and second secondary carriers are dormant, wherein the channel feedback report comprises channel interference feedback that is based on measurements of resources of the one or more secondary carriers while the first and second secondary carriers are dormant and channel quality feedback that is based on channel measurements of the one or more secondary carriers from a previous non-dormant period of the first and second secondary carriers.
16. The apparatus of claim 15 , wherein the means for monitoring monitors the one or more secondary carriers from the first carrier group for cell mode indicators associated with the one or more secondary carriers of the first set of secondary carriers.
17. The apparatus of claim 15 , wherein
the second carrier group comprises a special secondary carrier, and
wherein the means for monitoring monitors the special secondary carrier for cell mode indicators associated with the one or more secondary carriers of the second set of secondary carriers.
18. The apparatus of claim 15 , wherein
the second carrier group comprises a special secondary carrier, and
wherein the means for monitoring monitors the one or more secondary carriers of the second set of secondary carriers for cell mode indicators associated with the one or more secondary carriers of the second set of secondary carriers.
19. The apparatus of claim 15 , wherein the means for monitoring monitors one or more search spaces of at least a first carrier of the first carrier group and at least a second carrier of the second carrier group at predefined time intervals for downlink control information (DCI) comprising the indications of cell dormancy.
20. The apparatus of claim 15 , wherein the means for monitoring monitors the indications based on activation states of secondary carriers of the first and second sets of secondary carriers.
21. An apparatus for wireless communications, comprising:
means for determining a multiple carrier configuration including a first carrier group and a second carrier group,
the first carrier group being associated with a first base station and including a primary carrier only or the primary carrier and a first set of secondary carriers, and
the second carrier group being associated with a second base station and including a second set of secondary carriers, wherein one or more secondary carriers from the first set of secondary carriers or the second set of secondary carriers aperiodically transitions between being dormant and non-dormant;
means for monitoring the one or more secondary carriers for a cell mode indicator indicating that a secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant;
means for determining that a first secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is dormant based on a received cell mode indicator;
means for determining that a second secondary carrier from at least one of the first set of secondary carriers or the second set of secondary carriers is aperiodically dormant based at least in part on detecting an aperiodic transition between being non-dormant and being dormant from an absence of information related to dormancy for the second secondary carrier;
means for determining a channel state information (CSI) reporting configuration for the first and second secondary carriers based at least in part on the determining that the first and second secondary carriers are dormant; and
means for performing CSI reporting according to the CSI reporting configuration, wherein the CSI reporting configuration comprises a first antenna port configuration for reporting CSI when the first and second secondary carriers are dormant and a second antenna port configuration for reporting CSI when the first and second secondary carriers are non-dormant, the first antenna port configuration being different than the second antenna port configuration.
22. The apparatus of claim 21 , wherein the means for performing CSI reporting further comprises:
means for determining whether the first and second secondary carriers are associated with the first base station or the second base station,
and wherein the means for performing CSI reporting performs CSI reporting for the first and second secondary carriers to the first base station or to the second base station based on the determined association and according to the CSI reporting configuration.
23. The apparatus of claim 21 , wherein the first type of CSI comprises periodic CSI reporting and the second type of CSI comprises aperiodic CSI reporting.