WO2015070369A1

WO2015070369A1 - Apparatus and method for serving cell configuration for dual connectivity

Info

Publication number: WO2015070369A1
Application number: PCT/CN2013/086929
Authority: WO
Inventors: Haitao Li; Yang Liu
Original assignee: Nokia Technologies Oy; Nokia (China) Investment Co., Ltd.
Priority date: 2013-11-12
Filing date: 2013-11-12
Publication date: 2015-05-21

Abstract

According to an example embodiment of this invention, a method may include configuring a serving cell to be added or modified for a user equipment; generating an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and including the indicator in a configuration message to be sent to the user equipment.

Description

APPARATUS AND METHOD FOR SERVING CELL CONFIGURATION FOR

DUAL CONNECTIVITY

[0001] The presently described examples of embodiments of an invention relate generally to an apparatus and a method for serving cell configuration for dual connectivity and other related aspects.

[0002] The presently described examples of embodiments of the invention may be better appreciated by first contemplating the following passages.

[0003] In wireless communication, different collections of communication protocols are available to provide different types of services and capabilities. Long term evolution, LTE, is one of such collection of wireless communication protocols that extends and improves the performance of existing universal mobile telecommunications system, UMTS, protocols and is specified by different releases of the standard by the 3^rd generation partnership project, 3GPP, in the area of mobile network technology. Other non-limiting example wireless communication protocols include global system for mobile, GSM, high speed packet access, HSPA, and worldwide interoperability for microwave access, WiMAX.

[0004] The improvements of LTE are being made to cope with continuing new requirements and the growing base of users. Goals of this broadly based project include improving communication efficiency, lowering costs, improving services, making use of new spectrum opportunities, and achieving better integration with other open standards and backwards compatibility with some existing infrastructure that is compliant with earlier standards. The project envisions a packet switched communications environment with support for such services as voice over IP, VoIP. The 3GPP LTE project is not itself a standard-generating effort, but will result in new recommendations for standards for the UMTS. Now the project moved to planning the next generation standards, sometimes referred to as LTE-Advanced, LTE-A.

[0005] A goal of LTE-A is to provide significantly enhanced services by means of higher data rates and lower latency with reduced cost. LTE-A is directed toward extending and optimizing the current 3 GPP LTE radio access technologies to provide higher data rates at very low cost. LTE-A will be a more optimized radio system fulfilling the International Telecommunication Union Radio-communication sector, ITU-R, requirements for international mobile telecommunications - advanced, IMT-A, while maintaining backward compatibility with the current LTE release.

[0006] Integration of new network topologies into a cellular network may provide a context for some examples of embodiments of the present invention. Heterogeneous networks in LTE and LTE-A exemplify such integration. Heterogeneous network can include, for example, a deployment of macros, micros, picos, femtos and relays in the same spectrum. Dual connectivity operation under heterogeneous network has been studied recently, where a user equipment, UE, can connect to a macro cell evolved NodeB, MeNB, and a small cell eNB's or secondary eNB (SeNB). It has been observed that the UE's dual connectivity to MeNB and SeNB on different carriers can bring throughput gain and also mobility robustness gain.

SUMMARY STATEMENTS

[0007] Various aspects of examples of embodiments of the invention are set out in the claims.

[0008] According to a first aspect of an example of an embodiment of the present invention, there is provided a method comprising configuring a serving cell to be added or modified for a user equipment; generating an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and including the indicator in a configuration message to be sent to the user equipment.

[0009] According to a second aspect of an example of an embodiment of the present invention, there is provided an apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to configure a serving cell to be added or modified for a user equipment; generate an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and include the indicator in a configuration message to be sent to the user equipment.

[0010] According to a third aspect of an example of an embodiment of the present invention, there is provided a computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code may include code for configuring a serving cell to be added or modified for a user equipment; generating an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and including the indicator in a configuration message to be sent to the user equipment.

[0011] According to a fourth aspect of an example of an embodiment of the present invention, there is provided an apparatus comprising means for configuring a serving cell to be added or modified for a user equipment; means for generating an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and means for including the indicator in a configuration message to be sent to the user equipment.

[0012] According to a fifth aspect of an example of an embodiment of the present invention, there is provided a method comprising receiving a configuration message to add or modify a serving cell; detecting an indicator in the configuration message; and determining based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell.

[0013] According to a sixth aspect of an example of an embodiment of the present invention, there is provided an apparatus comprising at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to receive a configuration message to add or modify a serving cell; detect an indicator in the configuration message; and determine based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell.

[0014] According to a seventh aspect of an example of an embodiment of the present invention, there is provided a computer program product comprising a computer- readable medium bearing computer program code embodied therein for use with a computer, the computer program code may include code for receiving a configuration message to add or modify a serving cell; detecting an indicator in the configuration message; and determining based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell.

[0015] According to an eighth aspect of an example of an embodiment of the present invention, there is provided an apparatus comprising means for receiving a configuration message to add or modify a serving cell; means for detecting an indicator in the configuration message; and means for determining based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a more complete understanding of example embodiments of the present invention, reference is now made to the accompanying drawings which are by way of example only when taken in connection with the following description and in which:

[0017] Figure 1 illustrates an example of a wireless system implemented using the dual connectivity technology of the following example embodiments;

[0018] Figure 2 illustrates an example of an information element to indicate the serving cell configured with uplink resource for uplink control information transmission of a serving cell as described in an example embodiment;

[0019] Figure 3 illustrates a flow diagram of configuring a serving cell for dual connectivity user equipment as described in an example embodiment;

[0020] Figure 4 illustrates a flow diagram of a procedure performed by a dual connectivity user equipment as described in an example embodiment;

[0021] Figure 5 illustrates a simplified block diagram of various example apparatuses that are suitable for use in practicing various described example embodiments.

DETAILED DESCRIPTON

[0022] Figure 1 illustrates an example of a wireless system 100 implemented using the dual connectivity technology of the following example embodiments. The example wireless system 100 comprises a network element, NE, such as for example, a 3^rd generation partnership project, 3GPP, macro cell evolved NodeB, MeNB, 101 connecting to a core network that is not shown for brevity. The example wireless system 100 also comprises a small cell eNB or secondary eNB, SeNB, 103. The MeNB and SeNB are connected via Xn interface over a non-ideal backhaul 105. In an example scenario, a dual connectivity capable user equipment, UE, 102 connects to both the MeNB 101 and the SeNB 103, via a communication path 104, and 106, respectively. Although just one UE and one SeNB are shown in Figure 1 , it is only for the purpose of illustration and the example wireless system 100 may comprise any number of SeNB(s) and UE(s).

[0023] Both MeNB lOland SeNB 103 may support carrier aggregation, CA, within their coverage. Carrier aggregation allows expansion of effective bandwidth delivered to a user terminal through concurrent utilization of radio resource across multiple carriers. Multiple component carriers are aggregated to form a larger overall transmission bandwidth. When carrier aggregation is used there are a number of serving cells, namely primary cell, PCell, and secondary cell, SCell, one for each component carrier.

[0024] In an example embodiment, under one eNB, a UE has only one PCell and can have multiple SCells. Only PCell is configured with uplink resource such as for example physical uplink control channel, PUCCH, and the UE sends uplink control information, UCI, for all serving cells on PCell's PUCCH resource only. The UCI may comprise the channel quality indicator, CQI, acknowledgement, ACK, negative-acknowledgement, NACK, and so on. For dual connectivity operation with different eNBs connected with non-ideal backhaul, transmitting all UCIs over PCell under MeNB, MeNB-PCell, may be not practical as some scheduling related information may be very time-critical. In this case, having separate PUCCH resource configured for serving cell under SeNB is reasonable.

[0025] In an example embodiment, when a MeNB adds or configures a serving cell other than the PCell in the MeNB for the UE, it indicates to the UE whether this serving cell is in the serving cell group of MeNB and will use MeNB-PCell's PUCCH resource for UCI transmission, which can be literally called MeNB-SCell; or this serving cell is in the serving cell group of a SeNB and is configured with PUCCH resource, which can be literally called SeNB-PCell; or this serving cell is in the serving cell group of a SeNB and its UCI will be transmitted in the PUCCH resource of a SeNB-PCell, which can be literally called SeNB- SCell. This indication may be transmitted by such as for example, a radio resource control, RRC, message. After receiving this indication, the UE will transmit UCI for this added or modified serving cell on the correct serving cell accordingly.

[0026] In an example embodiment, in a configuration message for a serving cell other than MeNB-PCell, one extra information field, IE, "UCI transmission cell" is used to indicate the serving cell configured with uplink resource for UCI transmission of the concerned serving cell. From UE's perspective, it cannot tell which cell is from which eNB, but the cell for UCI transmission can be referenced by the cell index. For MeNB-SCell' s configuration, its UCI transmission cell may be the MeNB-PCell. For SeNB-PCell, MeNB may explicitly configure uplink resource such as for example PUCCH for it and the IE "UCI transmission cell" points to itself. For SeNB-SCell, the UCI transmission cell may be pointed to a SeNB-PCell. Note that this scheme does not limit to one SeNB aggregation case, but works also for multiple SeNB aggregation case, where multiple SeNB-PCells with multiple cell indices are configured.

[0027] Figure 2 illustrates an example of an IE to indicate the serving cell configured with uplink resource for UCI transmission of a serving cell as described in an example embodiment. In the example embodiment of Figure 2, an IE SCellToAddMod-rlO 200 is configured for adding or modifying a serving cell. It may include an IE uci- TransmissionCell-rl2 201 that indicates the cell index of a serving cell whose uplink resource can be used for UCI transmission of the added or modified serving cell.

[0028] In an example embodiment, the cell index of MeNB-PCell may be assigned as a predefined value, such as for example, 000. After receiving the IE uci-TransmissionCell- rl2 201, a UE may determine the type of the newly added or modified serving cell. For example, if the indicated cell index is 000, the newly added or modified serving cell is determined as a MeNB-SCell; if the indicated cell index is the cell identity of the newly added or modified serving cell itself with the value other than 000, the newly added or modified serving cell is determined as a SeNB-Pcell; if the indicated cell index refers to another cell with value other than 000, the newly added or modified serving cell is determined as a SeNB-SCell. In another example embodiment, a new type of cell indexes may be defined, such as for example, with range from 0 to 7, or the current cell indexes may be reused, in order to indicate different serving cells configured with uplink resource.

[0029] Figure 3 illustrates a flow diagram of configuring a serving cell for dual connectivity UE as described in an example embodiment. In Figure 3, a NE, such as for example, the macro eNB 101 of Figure 1, may configure a serving cell to be added or modified for a dual connectivity UE at 301. At 302, the NE may generate an indicator indicating the cell index of a serving cell whose uplink resource, such as for example, PUCCH, can be used for uplink control information transmission of the added or modified serving cell. The NE may insert the indicator into a configuration message that is sent to the UE at 303.

[0030] Figure 4 illustrates a flow diagram of a procedure performed by a dual connectivity UE as described in an example embodiment. In Figure 4, a UE, such as for example, the UE 102 of Figure 1, may receive a configuration message from a NE to add or modify a serving cell at 401. The UE may detect an indicator included in the configuration message at 402. The indicator indicates the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell. At 403, based on the indicator, the UE may determine the uplink resource to be used for transmission of its uplink control information.

[0031] Reference is made to Figure 5 for illustrating a simplified block diagram of various example apparatuses that are suitable for use in practicing various example embodiments of this invention. In Figure 5, a network element 501 is adapted for communication with a UE 511. The UE 511 may be capable for dual connectivity. The UE 511 includes at least one processor 515, at least one memory (MEM) 514 coupled to the at least one processor 515, and a suitable transceiver (TRANS) 513 (having a transmitter (TX) and a receiver (RX)) coupled to the at least one processor 515. The at least one MEM 514 stores a program (PROG) 512. The TRANS 513 is for bidirectional wireless communications with the NE 501.

[0032] The NE 501 includes at least one processor 505, at least one memory (MEM)

504 coupled to the at least one processor 505, and a suitable transceiver (TRANS) 503

(having a transmitter (TX) and a receiver (RX)) coupled to the at least one processor 505. The at least one MEM 504 stores a program (PROG) 502. The TRANS 503 is for bidirectional wireless communications with the UE 511. The NE 501 is coupled to one or more external networks or systems, which is not shown in this figure.

[0033] As shown in Figure 5, the NE 501 may further include a serving cell configuration unit of NE side 506. The unit 506, together with the at least one processor 505 and the PROG 502, may be utilized by the NE 501 in conjunction with various example embodiments of this invention, as described herein, such as for example, the procedure illustrated in Figure 3.

[0034] As shown in Figure 5, the UE 511 may further include serving cell configuration unit of UE side 516. The unit 516, together with the at least one processor 515 and the PROG 512, may be utilized by the UE 511 in conjunction with various example embodiments of this invention, as described herein, such as for example, the procedure illustrated in Figure 4.

[0035] At least one of the PROGs 502 and 512 is assumed to include program instructions that, when executed by the associated processor, enable the electronic apparatus to operate in accordance with the example embodiments of this disclosure, as discussed herein.

[0036] In general, the various example embodiments of the apparatus 511 can include, but are not limited to, cellular phones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions. [0037] The example embodiments of this disclosure may be implemented by computer software or computer program code executable by one or more of the processors 505, 515 of the NE 501 and the UE 511, or by hardware, or by a combination of software and hardware.

[0038] The MEMs 504 and 514 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. The processors 505 and 515 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi-core processor architecture, as non-limiting examples.

[0039] Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein may be that a UE may transmit UCI on the right serving cell for dual connectivity operation, which enables network's fast scheduling with no need of waiting for UCI information over non-ideal backhaul and thus throughput gain can be achieved.

[0040] Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware may reside on an apparatus such as a user equipment, a NodeB or other mobile communication devices. If desired, part of the software, application logic and/or hardware may reside on an eNodeB/base station 501, part of the software, application logic and/or hardware may reside on a UE 511, and part of the software, application logic and/or hardware may reside on other chipset or integrated circuit. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable medium may comprise a computer-readable storage medium that may be any media or means that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device.

[0041] Although various aspects of the example embodiment(s) described herein are set out in the accompanying independent claims, other aspects of the example embodiments of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

[0042] It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the general scope of inventive concept(s) of the example embodiments, at least one such inventive concept being as defined in the appended claims.

[0043] Further, the various names used for the described parameters are not intended to be limiting in any respect, as these parameters may be identified by any suitable names.

[0044] If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and example embodiments of this invention, and not in limitation thereof.

Claims

WHAT IS CLAIMED IS:

1. A method, comprising:

configuring a serving cell to be added or modified for a user equipment;

generating an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and

including the indicator in a configuration message to be sent to the user equipment.

2. The method as claimed in claim 1, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

3. A method, comprising:

receiving a configuration message to add or modify a serving cell;

detecting an indicator in the configuration message; and

determining based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell.

4. The method as claimed in claim 3, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

5. The method as claimed in any preceding claim, further comprising:

determining based on the indicator the type of the added or modified serving cell.

6. An apparatus comprising:

at least one processor, and at least one memory including computer program code, wherein the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

configure a serving cell to be added or modified for a user equipment;

generate an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and

include the indicator in a configuration message to be sent to the user equipment.

7. The apparatus as claimed in claim 6, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

8. An apparatus comprising:

receive a configuration message to add or modify a serving cell;

detect an indicator in the configuration message; and

determine based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell.

9. The apparatus as claimed in claim 8, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

10. The apparatus as claimed in any preceding claim, wherein the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus further to:

determine based on the indicator the type of the added or modified serving cell.

11. A computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code includes code for:

configuring a serving cell to be added or modified for a user equipment;

12. The computer program product as claimed in claim 11, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

13. A computer program product comprising a computer-readable medium bearing computer program code embodied therein for use with a computer, the computer program code includes code for:

receiving a configuration message to add or modify a serving cell;

detecting an indicator in the configuration message; and

14. The computer program product as claimed in claim 13, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

15. The computer program product as claimed in any preceding claim, wherein the computer program code further comprises code for:

16. An apparatus, comprising:

means for configuring a serving cell to be added or modified for a user equipment; means for generating an indicator indicating the cell index of a serving cell whose uplink resource can be used for uplink control information transmission of the added or modified serving cell; and means for including the indicator in a configuration message to be sent to the user equipment.

17. The apparatus as claimed in claim 16, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

18. An apparatus, comprising:

means for receiving a configuration message to add or modify a serving cell;

means for detecting an indicator in the configuration message; and

means for determining based on the indicator a serving cell whose uplink resources can be used for uplink control information transmission of the added or modified serving cell.

19. The apparatus as claimed in claim 18, wherein the added or modified serving cell is one of a secondary cell under a macro network element, a primary cell under a secondary network element, and a secondary cell under a secondary network element.

20. The apparatus as claimed in any preceding claim, further comprising:

means for determining based on the indicator the type of the added or modified serving cell.