Data scheduling on multi-carrier has been deployed to achieve higher data rates and load balancing. With the introduction of intra/inter-band features like DC-HSPA/DB-DC-HSPA, data can be scheduled over two carriers in the same band or in different bands. Along with the trend that the basic frequency for MBB coverage is a lower band, e.g. 900MHz, carrier aggregation of two carriers in a lower band and a higher band (cross band carrier aggregation), would become a typical deployment scenario for multi-carrier application.
In cross band carrier aggregation, the reliability of scheduling channels as HS-SCCH or E-AGCH, on the higher and lower frequency carriers is not the same. Assuming the primary carrier is the lower band, the scheduling channels on the secondary carrier are not as reliable as the ones on the primary carrier due to the higher path loss in the higher band.
Assuming scenarios where the secondary carrier operates in the higher frequency, in order to improve the performance of cross band carrier aggregation, the reliability of scheduling channels over the secondary carrier using the higher band should be investigated.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
: "Vocabulary for 3GPP Specifications".
TR 41.001: "GSM Release specifications".
→ to date, withdrawn by 3GPP
TR 21.912: (V3.1.0) "Example 2, using fixed text".
→ to date, withdrawn by 3GPP
RP-170719: "Study on scheduling enhancements with carrier aggregation for UMTS".
: (V13.0.0) "Radio Frequency (RF) system scenarios (Release 13)".
: (V14.0.0) "Physical Layer Procedures (FDD) ".
R1-1708890, Final report of RAN1#88bis meeting.
R1-1708739, "Analysis of the code allocation impact on the primary carrier for the SI on scheduling enhancements with carrier aggregation for UMTS", RAN1#89, Ericsson.
For the purposes of the present document, the terms and definitions given in TR 21.905
and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905
For the purposes of the present document, the following symbols apply:
For the purposes of the present document, the abbreviations given in TR 21.905
and the following apply.
An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905
The objective of the study item  is the following:
Identify the reliability issue of scheduling channels over the secondary (assuming high frequency) carrier for cross band carrier aggregation and investigate mechanisms to improve the reliability.
Study the reliability of scheduling channels over the secondary (assuming high frequency) carrier, e.g. the coverage difference, detection performance, under different carrier aggregation scenarios. (RAN1)
Investigate potential enhancement schemes to improve the reliability of scheduling channels over the secondary (assuming high frequency) carrier, and identify the impacts on current specifications for introducing such enhancements.(RAN1, RAN2)
Study the cost and gain for any proposed change with respect to the baseline for Dual Band Multicarrier scenarios.
The study shall include considerations to minimize the impact on legacy terminals.