WO2018203316A1

WO2018203316A1 - Downlink multicarrier transmissions in wireless communication networks

Info

Publication number: WO2018203316A1
Application number: PCT/IB2018/053166
Authority: WO
Inventors: Gerardo Agni MEDINA ACOSTA; Cecilia EKLÖF; Waikwok Kwong; Nianshan SHI
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2017-05-05
Filing date: 2018-05-07
Publication date: 2018-11-08

Abstract

A method in a radio network node includes indicating, in a downlink control message carrying a starting order, whether an upcoming downlink control message will occur in a second manner. The radio network node transmits, to a User Equipment (UE), the downlink control message carrying the starting order. The radio network node later transmits one or more upcoming downlink control message to the UE. In some embodiments, any upcoming downlink control message occurs in the second manner based on the transmission of the downlink control message carrying the starting order. In some embodiments, the radio network node later transmits, to the UE, a downlink control message carrying a stopping order. The time between the downlink control message carrying the starting order and the downlink control message carrying the stopping order defines a transmission interval during which any upcoming downlink control message occurs in the second manner.

Description

DOWNLINK MUL TIC A RRIE R TRANSMISSIONS IN WIRELESS

COMMUNICA TION NETWORKS

Related Applications

[0001] This application claims the benefit of provisional patent application serial number 62/502,238, filed May 5, 2017, the disclosure of which is hereby incorporated herein by reference in its entirety.

Technical Field

[0002] The present description generally relates to wireless communications and wireless communication networks, and more particularly relates to downlink multicarrier transmissions in wireless communication networks.

Background

[0003] At the RAN plenary #75, a new Study Item (SI) on scheduling enhancements with carrier aggregation for UMTS was approved in RP-170309, Meeting Report RAN1 #75. The Study Item Description (SID) associated to it contains the following objectives (see RP-170719, Study on scheduling enhancements with carrier aggregation for UMTS):

[0004] 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.

o 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 )

o 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 , - Study the cost and gain for any proposed change with respect to the baseline for Dual Band Multicarrier scenarios.

[0005] The study should include considerations to minimize the impact on legacy terminals or UEs.

[0006] The study basically aims at achieving a coverage balancing for downlink scheduling channels that are transmitted in different bands in downlink multicarrier scenario. The downlink multicarrier scenario being discussed here consist of having one pair of carriers (UL/DL pair) operating in a low frequency band, and another pair of carriers (UL/DL pair) in the high frequency band, this scheme is known as Dual Band Dual Carrier HSDPA (DB-DC HSDPA).

According to the SID, the primary carrier is the one configured on the low frequency band, while the secondary carrier is the one on the high frequency band.

[0007] During the study it was shown that there is a path-loss difference of around 7.2dB between a low (900MHz) frequency band and a high (2000MHz) frequency band. The above indicates that there is a natural imbalance between those bands given by the wavelengths associated to each carrier frequency. For that reason, any enhancements (e.g., performing repetitions) used to improve the coverage on a given carrier should be equally applicable on any other carrier regardless of its operation frequency (e.g., high frequency carrier or low frequency carrier), still leading to a coverage imbalance due to physics.

[0008] Even when there does not seem to be any physical layer mechanism that can be used to alleviate the imbalance between the carriers, one potential solution that was discussed during the 3GPP Meeting RAN1 #88bis was the possibility of moving the scheduling channels configured for the high frequency band to the low frequency band.

[0009] More specifically, the scheduling channel assessed during the 3GPP meeting was the HS-SCCH channel, which carries the control information associated with downlink channel that carries the actual data. According to the UMTS standard, each downlink carrier corresponding to a DB-DC HSDPA scenario counts with a group of HS-SCCH channels (known as HS-SCCH set) for the purpose of performing the downlink transmission (HS-DSCH transmissions) on each carrier. The HS-SCCH set contains up to 4 HS-SCCH, which allows the network to schedule up to four simultaneous users within the same transmission time interval (TTI).

[0010] The proposal of moving the scheduling channels from the high frequency band to low frequency band was made for the HS-SCCH. According to the Chairman's notes from RAN1 #88bis, two possibilities have been envisioned (see Chairman Notes 3GPP RAN1 #88bis, Spokane, USA):

[0011] When in a downlink multicarrier scenario, all the scheduling channels

(HS-SCCHs) are hosted in the low frequency carrier. At the receiver or UE side, there needs to have a way of knowing if the HS-SCCH transmitted from the low frequency carrier refers to an incoming downlink transmission in the low frequency carrier (primary carrier) or in the high frequency carrier (secondary carrier).

[0012] HS-SCCH Type 1 [0013] Here some background is provided on the HS-SCCH Type 1 , which is the one used for the purpose of transmitting the control information associated to the HS-DSCH transmissions on the primary and secondary carriers. From the technical background on the HS-SCCH it will be possible to realize the role the UE ID plays in the Layer 1 processing chain of the HS-SCCH Type 1.

[0014] The HS-SCCH Type 1 is a downlink control channel used for scheduling HS-DSCH transmissions as well as for instructing the UE to perform specific actions via HS-SCCH orders.

[0015] There are different HS-SCCH types, for example the HS-SCCH type 3 and 4 are used when the UE is configured in MIMO mode, and MIMO mode with four antennas, while the HS-SCCH type 2, known as "HS-SCCH less", is used for not having to transmit the HS-SCCH associated to the incoming DL data, reason why a blind detection has to be performed at the UE side.

[0016] From all different HS-SCCH types, this study item refers to the HS- SCCH Type 1 . In relation to it, below there is a description of the fields contained on the HS-SCCH control information Type 1 (see 3GPP TS 25.212):

[0017] Structure of the HS-SCCH Typel (Regular Control Information)

Channelization-code-set information (7 bits): x_CCs,i , x_CCs,2, x∞s,7

Modulation scheme information (1 bit): x_ms,i

- Transport-block size information (6 bits): x_tb_S,i , tbs,2, xtbs,6

Hybrid-ARQ process information (3 bits): Xhap,i , Xha_P,2, Xha_P,3

Redundancy and constellation version (3 bits): x_{rv 1} , x_{rv 2}, x_rv,3

New data indicator (1 bit): x_nci,i

UE identity (16 bits): x_ue,i , x_ue,2, x_Ue,ie

[0018] The HS-SCCH control information is transmitted in one subframe, which is composed by three slots. Both, the "Channelization-code-set

information" and "Modulation scheme information" are transmitted in the Slot 0 (known as HS-SCCH part 1 ), while the "Transport-block size information", "Hybrid-ARQ process information"," Redundancy and constellation version", and the "New data indicator" are conveyed over Slot 1 and Slot 2 (Known as HS- SCCH part 2). The "UE identity" is masked in both HS-SCCH part 1 and part 2, as part of the L1 processing chain.

[0019] The L1 processing chain of the HS-SCCH Type 1 is depicted in Figure 1 .

[0020] The description of Figure 1 is as follows. On the left hand side, "XUE" refers to the encoding version of the UE ID that is masked with the outcome of the branch dealing with the encoding version of the CCS and MS bits. On the other hand, the branch on right hand side refers to the encoding process of the bits carried on the HS-SCCH part 2, which are carried over both slot 1 and slot 2.

[0021] At the receiver side, the Part I (slot 0) is detected/decoded first, if this process results successful (i.e., "passed") then it is possible to proceed to decode the Part II (slots 1 and 2) of the HS-SCCH (Part II makes use of the decoded information obtained from Part I). This means that the detection and decoding of slot 0 is a key aspect of the performance of the HS-SCCH.

[0022] The transmission and reception of the HS-SCCH part I (slot 0) is described below in general terms:

[0023] Transmitter

[0024] At the final step of the L1 processing chain associated with Part I, an encoded version of the UE ID is masked with an encoded version of the control information bits. The masked bits (40bits) are modulated and later on transmitted over the air.

[0025] Channel

[0026] The channel distorts the modulated symbols as a function of the

Eb/No.

[0027] Receiver

[0028] The symbols distorted by the channel are demodulated, the recovered bits are unmasked by using the same UE ID which is known by the mobile entity.

The outcome from the unmasked process is a recovered encoded version of the control information bits, which are given as input of a decoder (e.g., either a Viterbi decoder or a "Sequential Maximum Likelihood Correlator") that will allow to recover the control information bits (CCS bits & MS bit) carried over slot 0. Summary

[0029] In some embodiments, a method in a radio network node includes the radio network node indicating through a downlink control message a starting order from which any upcoming downlink control message will occur in a second manner which is different than the first manner used prior to the starting order. The radio network node transmits, to a User Equipment (UE), in a downlink control channel on a first downlink carrier, the downlink control message carrying the starting order. The radio network node later transmits the upcoming downlink control message to the UE on the first downlink carrier. In some embodiments, the upcoming downlink control message occurs in the second manner based on the prior transmission of the downlink control message carrying the starting order. In some embodiments, the radio network node later transmits, to the UE, in the downlink control channel, a downlink control message with a stopping order from which any upcoming downlink control message will occur in a first manner.

[0030] In some embodiments, the time between the downlink control message carrying the starting order and the downlink control message carrying the stopping order defines a transmission interval during which any upcoming downlink control message occurs in a second manner which is different than a first manner outside the interval. In some embodiments, the downlink control message carrying the starting order and the downlink control message carrying the stopping order are different.

[0031] When in a downlink multicarrier scenario, all the scheduling channels (HS-SCCHs) are hosted in the low frequency carrier. At the receiver or UE, there needs to be way of knowing (i.e., distinguishing) if the HS-SCCH transmitted on the low frequency carrier refers to an incoming downlink transmission on the low frequency carrier or on the high frequency carrier. More generally, at the receiver or UE, there needs to be way of knowing (i.e., distinguishing) if the HS-SCCH transmitted on the first frequency carrier refers to an incoming downlink transmission on the first frequency carrier or on second high frequency carrier. [0032] In one broad embodiment, the radio network node and the UE use two different H-RNTIs for the primary carrier (each of them referred as "UE identity" at the physical layer), one for receiving scheduling downlink transmissions intended for the primary (or first) carrier and one for receiving scheduling downlink transmissions intended for the secondary (or second) carrier. The UE can try to decode the received information by using the H-RNTI associated to primary carrier first, and then try with the second H-RNTI in case the first decoding attempt failed. The UE can try to perform the decoding in reverse order (i.e., H-RNTI for the secondary carrier first, and the H-RNTI for primary carrier second), or even simultaneously.

[0033] In another broad embodiment, one of the information bits transmitted in slot 0 on the HS-SCCH is reinterpreted for indicating if it is the primary carrier or the secondary carrier that is being scheduled.

[0034] Both the radio network node and the UE can get prepared to start using either of the above mechanisms upon establishing the RRC configuration, or on demand through the use of an HS-SCCH order indicating the UE to get prepared for start decoding using two H-RNTIs on the primary carrier, or by reinterpreting one of the fields carried on the HS-SCCH. Moreover, two HS-SCCH orders (or the same one transmitted twice) could be used to start and stop a time interval within which the transmitted HS-SCCHs should be understood to be intended for the secondary carrier, while any HS-SCCH transmission outside such a time interval should be understood to be intended for the primary carrier. As discussed in more detail below in relation to Figures 9 and 10, these two HS- SCCH orders could be used to create a transmission interval that has a start time of the first HS-SCCH order and a stop time of the second HS-SCCH order. In some embodiments, when messages are received during the transmission interval, they are understood in a second manner. If they are received outside of the transmission interval (before or after), then they are understood in a first manner.

[0035] According to one aspect, some embodiments include a method in a radio network node. The method comprises identifying, in a downlink control message, whether an upcoming downlink transmission will occur on a first downlink carrier or on a second downlink carrier, transmitting, to a User

Equipment, UE, in a downlink control channel on the first downlink carrier, the downlink control message indicative of the upcoming downlink transmission, and transmitting the downlink transmission to the UE on the identified downlink carrier.

[0036] In some embodiments, identifying whether the upcoming downlink transmission will occur on the first downlink carrier or on the second downlink carrier may comprise masking at least a control portion of the downlink control message with one of a first UE identifier and a second UE identifier, wherein the first UE identifier identifies the first downlink carrier and wherein the second UE identifier identifies the second downlink carrier. In such embodiments, the second UE identifier may be a bit-wise inversion of the first UE identifier or may be a newly defined UE identifier. In such embodiments, the first and second UE identifiers may be High-speed Radio Network Temporary Identifiers, H-RNTIs.

[0037] In some embodiments, identifying whether the upcoming downlink transmission will occur on the first downlink carrier or on the second downlink carrier may comprise setting a bit to one of two possible values in a control portion of the downlink control message, wherein a first of the two possible values identifies the first downlink carrier and wherein a second of the two possible values identifies the second downlink carrier.

[0038] According to another aspect, some embodiments include a radio network node configured, or operable, to perform one or more radio network node functionalities (e.g. steps, actions, etc.) as described herein.

[0039] In some embodiments, the radio network node may comprise a communication interface configured to communicate with one or more User Equipments, with one or more other radio network node and/or with one or more network nodes (e.g. core network nodes), and processing circuitry operatively connected to the communication interface, the processing circuitry being configured to perform one or more radio network node functionalities as described herein. In some embodiments, the processing circuitry may comprise at least one processor and at least one memory storing instructions which, upon being executed by the processor, configure the processor to perform one or more radio network node functionalities as described herein.

[0040] In some embodiments, the radio network node may comprise one or more functional modules configured to perform one or more radio network node functionalities as described herein.

[0041] According to another aspect, some embodiments include a non- transitory computer-readable medium storing a computer program product comprising instructions which, upon being executed by processing circuitry (e.g., a processor) of the radio network node, configure the processing circuitry to perform one or more radio network node functionalities as described herein.

[0042] According to one aspect, some embodiments include a method in a User Equipment, UE. The method comprises receiving, from a radio network node, a downlink control message indicative of an upcoming downlink

transmission, the downlink control message being received in a downlink control channel on a first downlink carrier, determining, from the received downlink control message, whether the upcoming downlink transmission will occur on the first downlink carrier or on a second downlink carrier, and receiving the downlink transmission on the determined downlink carrier.

[0043] In some embodiments, determining whether the upcoming downlink transmission will occur on the first downlink carrier or on the second downlink carrier may comprise decoding at least a control portion of the downlink control message with at least one of a first UE identifier and a second UE identifier, wherein successful decoding of at least the control portion of the downlink control message with the first UE identifier indicates that the upcoming downlink transmission will occur on the first downlink carrier, and wherein successful decoding of at least the control portion of the downlink control message with the second UE identifier indicates that the upcoming downlink transmission will occur on the second downlink carrier. In such embodiments, the second UE identifier may be a bit-wise inversion of the first UE identifier or may be a newly defined UE identifier. In such embodiments, the first and second UE identifiers are Highspeed Radio Network Temporary Identifiers, H-RNTIs.

[0044] In some embodiments, determining whether the upcoming downlink transmission will occur on the first downlink carrier or on the second downlink carrier may comprise determining a value of a bit in a control portion of the downlink control message, the bit having one of two possible values, wherein a first of the two possible values identifies the first downlink carrier and wherein a second of the two possible values identifies the second downlink carrier.

[0045] According to another aspect, some embodiments include a UE configured, or operable, to perform one or more UE functionalities (e.g. steps, actions, etc.) as described herein.

[0046] In some embodiments, the UE may comprise a communication interface configured to communicate with one or more radio network nodes and/or with one or more network nodes (e.g. core network nodes), and processing circuitry operatively connected to the communication interface, the processing circuitry being configured to perform one or more UE functionalities as described herein. In some embodiments, the processing circuitry may comprise at least one processor and at least one memory storing instructions which, upon being executed by the processor, configure the processor to perform one or more UE functionalities as described herein.

[0047] In some embodiments, the UE may comprise one or more functional modules configured to perform one or more UE functionalities as described herein.

[0048] According to another aspect, some embodiments include a non- transitory computer-readable medium storing a computer program product comprising instructions which, upon being executed by processing circuitry (e.g., a processor) of the UE, configure the processing circuitry to perform one or more UE functionalities as described herein.

[0049] Some embodiments may enable the UE to distinguish between the primary (or first) carrier and the secondary (or second) carrier when the control information (HS-SCCH) intended for either of them has been transmitted from the carrier having better propagation properties. Some embodiments may be compatible with the existing UMTS standard by making use to what is available in the legacy framework (e.g., re-using the two H-RNTIs already known to the UE). Depending on the embodiments, it might be possible to avoid collisions, save UE processing (e.g., sequential decoding), and/or reduce the amount of required signaling.

[0050] Other aspects and features will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.

Brief Description of the Drawings

[0051] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0052] Figure 1 illustrates a block diagram of the coding chain for the High Speed-Shared Control Channel (HS-SCCH) type 1 ;

[0053] Figure 2 illustrates a schematic diagram of an example communication network in accordance with some embodiments;

[0054] Figure 3 illustrates a signaling diagram in accordance with some embodiments;

[0055] Figure 4 illustrates another signaling diagram in accordance with some embodiments;

[0056] Figure 5 illustrates another signaling diagram in accordance with some embodiments;

[0057] Figure 6 illustrates another signaling diagram in accordance with some embodiments;

[0058] Figure 7 illustrates a flow chart of operations of a User Equipment (UE) in accordance with some embodiments;

[0059] Figures 8 illustrates a flow chart of operations of a radio network node in accordance with some embodiments; [0060] Figure 9 illustrates a flow chart of operations of a radio network node in accordance with some embodiments;

[0061] Figure 10 illustrates a flow chart of operations of a UE in accordance with some embodiments;

[0062] Figure 1 1 is a schematic block diagram of a radio access node according to some embodiments of the present disclosure;

[0063] Figure 12 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node of Figure 1 1 according to some

embodiments of the present disclosure;

[0064] Figure 13 is a schematic block diagram of the radio access node of

Figure 1 1 according to some other embodiments of the present disclosure;

[0065] Figure 14 is a schematic block diagram of a User Equipment device

(UE) according to some embodiments of the present disclosure; and

[0066] Figure 15 is a schematic block diagram of the UE of Figure 14 according to some other embodiments of the present disclosure.

Detailed Description

[0067] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0068] In the following description, numerous specific details are set forth. However, it is understood that embodiments may be practiced without these specific details. In other instances, well-known circuits, structures, and

techniques have not been shown in detail in order not to obscure the

understanding of the description. Those of ordinary skill in the art, with the included description, will be able to implement appropriate functionality without undue experimentation. [0069] References in the specification to "one embodiment," "an

embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0070] As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0071] Radio Node: As used herein, a "radio node" is either a radio access node or a wireless device.

[0072] Radio Access Node: As used herein, a "radio access node" or "radio network node" is any node in a radio access network of a cellular

communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high- power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), and a relay node.

[0073] Core Network Node: As used herein, a "core network node" is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P- GW), a Service Capability Exposure Function (SCEF), or the like.

[0074] Wireless Device: As used herein, a "wireless device" is any type of device that has access to (i.e., is served by) a cellular communications network by wirelessly transmitting and/or receiving signals to a radio access node(s). Some examples of a wireless device include, but are not limited to, a User Equipment device (UE) in a 3GPP network and a Machine Type Communication (MTC) device.

[0075] Network Node: As used herein, a "network node" is any node that is either part of the radio access network or the core network of a cellular communications network/system.

[0076] Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

[0077] Note that, in the description herein, reference may be made to the term "cell;" however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

[0078] Figure 2 illustrates an example of a wireless network 100 that may be used for wireless communications. Wireless network 100 includes UEs 1 10A- H OB (collectively referred to as UE or UEs 1 10) and a plurality of radio network nodes 120A-120B (e.g., NBs, RNCs, eNBs, etc.) (collectively referred to as radio network node or radio network nodes 120) directly or indirectly connected to a core network 130 which may comprise various core network nodes. The network 100 may use any suitable radio access network (RAN) deployment scenarios, including UMTS Terrestrial Radio Access Network, UTRAN, and Evolved UMTS Terrestrial Radio Access Network, EUTRAN. UEs 1 10 within coverage areas 1 15 may each be capable of communicating directly with radio network nodes 120 over a wireless interface. In certain embodiments, UEs may also be capable of communicating with each other via device-to-device (D2D) communication. [0079] As an example, UE 1 10A may communicate with radio network node 120A over a wireless interface. That is, UE 1 10A may transmit wireless signals to and/or receive wireless signals from radio network node 120A. The wireless signals may contain voice traffic, data traffic, control signals, and/or any other suitable information. In some embodiments, an area of wireless signal coverage associated with a radio network node 120 may be referred to as a cell.

[0080] Within the context of DB-DC multicarrier scenario, when all the HS- SCCHs are hosted and transmitted from the carrier having better propagation properties, solutions are provided for distinguishing if the scheduled transmission was intended for the primary carrier or for the secondary carrier.

[0081] In one broad embodiment, the radio network node and the UE use two different H-RNTIs for the primary carrier (known each of them as "UE identity" at the physical layer), one for scheduling downlink transmissions on the primary carrier and one for scheduling downlink transmissions on the secondary carrier.

[0082] In another broad embodiment, one of the information bits transmitted in slot 0 on the HS-SCCH is reinterpreted for indicating whether it is the primary or secondary carrier that is being scheduled.

[0083] Both the radio network node and the UE can get prepared to start using either of the above mechanisms upon establishing the RRC configuration, or on demand through the use of a new HS-SCCH order indicating the UE to get prepared for start decoding using two H-RNTIs on the primary carrier, or by reinterpreting one of the fields carried on the HS-SCCH. Two HS-SCCH orders (or single HS-SCCH order used twice) could be used to start and stop a time interval within which the HS-SCCH should be understood to be intended for the secondary carrier, while any HS-SCCH outside that interval should be

understood to be intended for the primary carrier. As discussed in more detail below in relation to Figures 9 and 10, these two HS-SCCH orders could be used to create a transmission interval that has a start time of the first HS-SCCH order and a stop time of the second HS-SCCH order. In some embodiments, when messages are received during the transmission interval, they are understood in a second manner. If they are received outside of the transmission interval (before or after), then they are understood in a first manner.

[0084] According with the discussions that Technical Specification Working Group 1 has had on the study Item entitled "on scheduling enhancements with carrier aggregation for UMTS", the HS-SCCH is the channel that has been planned to be always transmitted from the carrier on low frequency band for handling the downlink transmission of carrier on low and high frequency bands.

[0085] Referring now to Figure 3, a high-level signaling diagram according to some embodiments is illustrated. As shown, when operating in DB-DC, the radio network node 120 identifies, in a downlink control message, on which of a first downlink carrier and a second downlink carrier an upcoming downlink

transmission will occur (action S102). As already indicated above, the

identification of the downlink carrier can be done is various ways. In some embodiments, the downlink control message (or a control portion of the downlink control message) is masked with one of a first and second UE identifiers, the first UE identifier identifying the first downlink carrier and the second UE identifier identifying the second downlink carrier. In some other embodiments, a bit in the downlink control message can be set to one of two possible values, a first one of the two possible values identifying the first downlink carrier and a second one of the two possible values identifying the second downlink carrier. Regardless of how the first and second downlink carriers are identified, the radio network node 120 transmits the downlink control message to the UE 1 10 on a downlink control channel on the first downlink carrier (action S104).

[0086] After having received the downlink control message, the UE 1 10 determines on which of the first and second downlink carrier the upcoming downlink transmission will occur (action S106). In some embodiments, the UE 1 10 may determine on which of the first and second downlink carriers the upcoming downlink transmission will occur by decoding the masked portion of the downlink control message with at least one of the first and second UE identifiers. If decoding with the first UE identifier is successful, the UE 1 10 determines that the upcoming downlink transmission will occur on the first downlink carrier. If decoding with the second UE identifier is successful, the UE 1 10 determines that the upcoming downlink transmission will occur on the second downlink carrier. In some other embodiments, the UE 1 10 may determine on which of the first and second downlink carriers the upcoming downlink transmission will occur by determining a value of a bit in the downlink control message, the bit having one of two possible values. If the UE determines the bit to have a first of the two possible values, the UE 1 10 determines that the upcoming downlink transmission will occur on the first downlink carrier. If the UE determines the bit to have a second of the two possible values, the UE 1 10 determines that the upcoming downlink transmission will occur on the second downlink carrier. Regardless of how the UE 1 10 determines whether the upcoming downlink transmission will occur on the first downlink carrier or on the second downlink carrier, the UE 1 10 then receives the downlink transmission on the identified (and subsequently determined) downlink carrier (action S108).

[0087] Some particular embodiments will now be described. In the

embodiments presented below, it is assumed that the low frequency carrier is the first or primary carrier. However, the embodiments are also applicable if the first or primary carrier is not the low frequency carrier.

[0088] Embodiment 1

[0089] Once the role of UE ID within the L1 processing chain of the HS-SCCH has been described, the following describes how to make use of different UE Identities to distinguish from a HS-SCCH transmission performed from the low frequency carrier which can be intended for any of the carriers in DB-DC HSDPA scenario.

[0090] Variant 1 :

[0091] With reference to Figure 4, H-RNTI 1 is allocated for the primary carrier, and H-RNTI 2 is allocated for the secondary carrier. When the primary carrier is used to transmit the HS-SCCH associated to the primary carrier, at the radio network node side, the HS-SCCH control information is masked with H- RNTI 1 . When the secondary carrier is used to transmit the HS-SCCH associated to the secondary carrier, at the radio network node side, the HS-SCCH control information is masked with H-RNTI 2.

[0092] Once the symbols distorted by the channel have been demodulated by the UE, the unmasking process may be performed first by using UE ID (e.g. H- RNTI) associated to the primary carrier, and then, if the criteria for proceeding to decode is not fulfilled (e.g., passing a correlation threshold), the UE can try to perform the unmasking process by using the UE ID associated to the secondary carrier. In this case, if the criteria are passed, the UE will know that the HS- SCCH transmission refers to the secondary carrier.

[0093] It could be up to the UE to decide which hypothesis to try first (i.e., unmasking first with the UE ID associated to the primary carrier, and then with the UE ID associated to the secondary carrier, or vice versa). More advanced UEs may even perform a dual unmasking process simultaneously, that is, the demodulated symbols may be unmasked using the UE ID associated to the primary carrier and the UE ID associated to the secondary carrier at the same time.

[0094] The radio network node and UE behavior for the masking could also be specified, e.g., in 3GPP TS 25.212, 25.321 and/or 25.331 .

[0095] Variant 2:

[0096] With reference to Figure 5, the H-RNTI (UE ID) used for transmissions associated to the secondary carrier is the inverted version (i.e., bit inversion) of the H-RNTI (UE ID) used for transmissions associated to the primary carrier.

[0097] According to this variant, the transmission/reception of a HS-SCCH transmitted from carrier on the low frequency band would be handled as follows:

- Transmission intended for the primary carrier: There is no change with respect to how the transmission/reception process of the HS-SCCH is done with respect to the current UMTS standard.

- Transmission intended for the secondary carrier: To start with, at the radio network node side, the UE ID that was used for performing the HS-SCCH transmissions for the primary carrier is inverted. For example, if the UE ID used on the primary carrier was '1 1 1 1 1 1 1 1 1 1 100000', then the UE ID to be used on the secondary would be Ό00000000001 1 1 1 1 '.

[0098] At the radio network node, the L1 processing chain depicted in Figure 1 would be followed by using inverted version of the UE ID used on primary carrier (in this example: Ό00000000001 1 1 1 1 ').

[0099] At the UE, once the symbols distorted by the channel have been demodulated, the unmasking process could be performed first by using regular UE ID (i.e., the one associated to the primary carrier), and then if the criteria for proceeding to decode is not fulfilled (e.g., passing a correlation threshold), the UE can try to perform the unmasking process by using the inverted version of the UE ID. In this case, if the criteria are passed, the UE will know that the HS-SCCH transmission refers to the secondary carrier.

[0100] It could be up to the UE to decide which hypothesis to try first (i.e., unmasking first with the regular UE ID, and then with the inverted version of the UE ID, or vice versa). More advanced UEs may even perform a dual unmasking process simultaneously, that is, the demodulated symbols may be unmasked using the regular UE ID and the inverted version of the UE ID at the same time.

[0101] In terms of avoiding collisions, the inverted version of the UE ID will correspond to another UE ID within the universe of user identities. However, there are 65536 (2¹⁶) different user identities and a collision is unlikely to happen. Nonetheless, the network could carefully choose which UE IDs to use so collisions are avoided (e.g., using a subgroup of UE IDs for the primary and another for the secondary carrier).

[0102] The radio network node and UE behavior for the masking could also be specified, e.g. in 3GPP TS 25.212, 25.321 and/or 25.331 .

[0103] Variant 3:

[0104] With reference to Figure 6, the radio network node could allocate two H-RNTIs for the primary carrier and they would be communicated to the UE. When the primary carrier is used to transmit the HS-SCCH associated to the secondary carrier, at the radio network node, the HS-SCCH is masked with a new H-RNTI (e.g., H-RNTI-new). In such variant, the impact would be on 3GPP TS 25.433, 25.423, and/or 25.331.

[0105] Embodiment 2

[0106] In this embodiment, one of the information bits transmitted in slot 0 on the HS-SCCH is reinterpreted for indicating whether it is the primary or secondary cell that is being scheduled. For example: If QPSK is assumed to be used in a predetermined manner, then the Modulation Scheme bit carrier on the slot 0 of the HS-SCCH can be used to distinguish if the transmission was for the primary or the secondary carrier. The impact may on TS 25.212.

[0107] Figure 7 is a flow chart that illustrates operations of the radio network node in accordance with some embodiments. As illustrated, the radio network node 120 identifies, in a downlink control message, whether an upcoming downlink transmission will occur on a first downlink carrier or on a second downlink carrier (action S202). The radio network node 120 then transmits, to a UE, in a downlink control channel on the first downlink carrier, the downlink control message indicative of the upcoming downlink transmission (action S204). Subsequently, the radio network node 120 transmits the downlink transmission to the UE on the identified downlink carrier (i.e., the first downlink carrier or the second downlink carrier).

[0108] Figure 8 is a flow chart that illustrates operations of the UE in accordance with some embodiments. As illustrated, the UE 1 10 receives, from a radio network node, a downlink control message indicative of an upcoming downlink transmission, the downlink control message being received in a downlink control channel on a first downlink carrier (action S302). After having received the downlink control message, the UE 1 10 determines, from the received downlink control message, whether the upcoming downlink

transmission will occur on the first downlink carrier or on a second downlink carrier (action S304). Subsequently, the UE 1 10 receives the downlink transmission on the determined downlink carrier (i.e., the first downlink carrier or the second downlink carrier). [0109] Figure 9 illustrates a flow chart of operations of a radio network node 120 in accordance with some embodiments. The radio network node 120 indicates, in a downlink control message carrying a starting order, whether any upcoming downlink control message will occur in a second manner (action S400). The radio network node 120 then transmits, to UE 1 10, in a downlink control channel on a first downlink carrier, the downlink control message carrying the starting order (action S402). The radio network node 120 later transmits the upcoming downlink control message to the UE 1 10 on the first downlink carrier (action S404). In some embodiments, the upcoming downlink control message occurs in the second manner based on the transmission of the downlink control message carrying the starting order. In some embodiments, the radio network node 120 later transmits, to the UE 1 10, in the downlink control channel, a downlink control message carrying a stopping order.

[0110] The time between the downlink control message carrying the starting order and the downlink control message carrying the stopping order defines a transmission interval during which any upcoming downlink control message occurs in the second manner. In some embodiments, the downlink control message carrying the starting order and the downlink control message carrying the stopping order are different.

[0111] Figure 10 illustrates a flow chart of operations of a UE 1 10 in accordance with some embodiments. The UE 1 10 receives, from the radio network node 120, a downlink control message carrying the starting order; the downlink control message is received in a downlink control channel on a first downlink carrier (action S500). The UE 1 10 determines, from the downlink control message carrying the starting order, whether any upcoming downlink control message will occur in a second manner (action S502). Then, the UE 1 10 receives one or more upcoming downlink control message (action S504). As discussed above, if any of the upcoming downlink control message is received during the transmission interval defined by the time between the downlink control message carrying the starting order and the downlink control message carrying the stopping order, then the UE 1 10 understands that the upcoming downlink control message occurs in the second manner. Otherwise, the UE 1 10 understands that the upcoming downlink control message occurs in the first manner.

[0112] Figure 1 1 is a schematic block diagram of a radio access node 1 100 according to some embodiments of the present disclosure. The radio access node 1 100 may be, for example, a radio network node 120. As illustrated, the radio access node 1 100 includes a control system 1 102 that includes one or more processors 1 104 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory 1 106, and a network interface 1 108. The one or more processors 1 104 are also referred to herein as processing circuitry. In addition, the radio access node 1 100 includes one or more radio units 1 1 10 that each includes one or more transmitters 1 1 12 and one or more receivers 1 1 14 coupled to one or more antennas 1 1 16. The radio units 1 1 10 may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) 1 1 10 is external to the control system 1 102 and connected to the control system 1 102 via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) 1 1 10 and potentially the antenna(s) 1 1 16 are integrated together with the control system 1 102. The one or more processors 1 104 operate to provide one or more functions of a radio access node 1 100 as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 1 106 and executed by the one or more processors 1 104.

[0113] Figure 12 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 1 100 according to some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. Further, other types of network nodes may have similar virtualized architectures.

[0114] As used herein, a "virtualized" radio access node is an implementation of the radio access node 1 100 in which at least a portion of the functionality of the radio access node 1 100 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the radio access node 1 100 includes the control system 1 102 that includes the one or more processors 1 104 (e.g., CPUs, ASICs, FPGAs, and/or the like), the memory 1 106, and the network interface 1 108 and the one or more radio units 1 1 10 that each includes the one or more transmitters 1 1 12 and the one or more receivers 1 1 14 coupled to the one or more antennas 1 1 16, as described above. The control system 1 102 is connected to the radio unit(s) 1 1 10 via, for example, an optical cable or the like. The control system 1 102 is connected to one or more processing nodes 1200 coupled to or included as part of a network(s) 1202 via the network interface 1 108. Each processing node 1200 includes one or more processors 1204 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 1206, and a network interface 1208.

[0115] In this example, functions 1210 of the radio access node 1 100 described herein are implemented at the one or more processing nodes 1200 or distributed across the control system 1 102 and the one or more processing nodes 1200 in any desired manner. In some particular embodiments, some or all of the functions 1210 of the radio access node 1 100 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 1200. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 1200 and the control system 1 102 is used in order to carry out at least some of the desired functions 1210. Notably, in some embodiments, the control system 1 102 may not be included, in which case the radio unit(s) 1 1 10 communicate directly with the processing node(s) 1200 via an appropriate network interface(s).

[0116] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of radio access node 1 100 or a node (e.g., a processing node 1200) implementing one or more of the functions 1210 of the radio access node 1 100 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0117] Figure 13 is a schematic block diagram of the radio access node 1 100 according to some other embodiments of the present disclosure. The radio access node 1 100 includes one or more modules 1300, each of which is implemented in software. The module(s) 1300 provide the functionality of the radio access node 1 100 described herein. This discussion is equally applicable to the processing node 1200 of Figure 12 where the modules 1300 may be implemented at one of the processing nodes 1200 or distributed across multiple processing nodes 1200 and/or distributed across the processing node(s) 1200 and the control system 1 102.

[0118] Figure 14 is a schematic block diagram of a UE 1400 according to some embodiments of the present disclosure. UE 1400 could be a UE 1 10, for example. As illustrated, the UE 1400 includes one or more processors 1402 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 1404, and one or more transceivers 1406 each including one or more transmitters 1408 and one or more receivers 1410 coupled to one or more antennas 1412. The processors 1402 are also referred to herein as processing circuitry. The transceivers 1406 are also referred to herein as radio circuitry. In some embodiments, the functionality of the UE 1400 described above may be fully or partially implemented in software that is, e.g., stored in the memory 1404 and executed by the processor(s) 1402. Note that the UE 1400 may include additional components not illustrated in Figure 14 such as, e.g., one or more user interface components (e.g., a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like), a power supply (e.g., a battery and associated power circuitry), etc.

[0119] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the UE 1400 according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0120] Figure 15 is a schematic block diagram of the UE 1400 according to some other embodiments of the present disclosure. The UE 1400 includes one or more modules 1500, each of which is implemented in software. The module(s) 1500 provide the functionality of the UE 1400 described herein.

[0121] Some embodiments may be represented as a non-transitory software product stored in a machine-readable medium (also referred to as a computer- readable medium, a processor-readable medium, or a computer usable medium having a computer readable program code embodied therein). The machine- readable medium may be any suitable tangible medium including a magnetic, optical, or electrical storage medium including a diskette, compact disk read only memory (CD-ROM), digital versatile disc read only memory (DVD-ROM) memory device (volatile or non-volatile), or similar storage mechanism. The machine- readable medium may contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to one or more of the described embodiments. Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described embodiments may also be stored on the machine-readable medium. Software running from the machine-readable medium may interface with circuitry to perform the described tasks.

[0122] The above-described embodiments are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the description.

[0123] While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

[0124] At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).

• 3GPP Third Generation Partnership Project

• 5G Fifth Generation

• AP Access Point

• ASIC Application Specific Integrated Circuit

• BSC Base Station Controller

• BTS Base Transceiver Station

• CD Compact Disk

• COTS Commercial Off-the-Shelf

• CPE Customer Premise Equipment

• CPU Central Processing Unit

• D2D Device-to-Device

• DAS Distributed Antenna System

• DSP Digital Signal Processor

• DVD Digital Video Disk

• eNB Enhanced or Evolved Node B

• E-SMLC Evolved Serving Mobile Location Center

• FPGA Field Programmable Gate Array

• GHz Gigahertz

• gNB New Radio Base Station

• GSM Global System for Mobile Communications

• loT Internet of Things

• IP Internet Protocol

• LEE Laptop Embedded Equipment

• LME Laptop Mounted Equipment • LTE Long Term Evolution

• M2M Machine-to-Machine

• MANO Management and Orchestration

• MCE Multi-Cell/Multicast Coordination Entity

• MDT Minimization of Drive Tests

• MIMO Multiple Input Multiple Output

• MME Mobility Management Entity

• MSC Mobile Switching Center

• MSR Multi-Standard Radio

• MTC Machine Type Communication

• NB-loT Narrowband Internet of Things

• NFV Network Function Virtualization

• NIC Network Interface Controller

• NR New Radio

• O&M Operation and Maintenance

• OSS Operations Support System

• OTT Over-the-Top

• PDA Personal Digital Assistant

• P-GW Packet Data Network Gateway

• RAM Random Access Memory

• RAN Radio Access Network

• RAT Radio Access Technology

• RF Radio Frequency

• RNC Radio Network Controller

• ROM Read Only Memory

• RRH Remote Radio Head

• RRU Remote Radio Unit

• SCEF Service Capability Exposure Function

• SOC System on a Chip

• SON Self-Organizing Network UE User Equipment

USB Universal Serial Bus

V2I Vehicle-to-lnfrastructure

V2V Vehicle-to-Vehicle

V2X Vehicle-to-Everything

VMM Virtual Machine Monitor

VNE Virtual Network Element

VNF Virtual Network Function

VoIP Voice over Internet Protocol

WCDMA Wideband Code Division Multiple Access

WiMax Worldwide Interoperability for Microwave Access

[0125] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims What is claimed is:

1 . A method in a radio network node, the method comprising:

indicating (S400), in a downlink control message a starting order, from which any upcoming downlink control message will occur in a second manner which is different than a first manner used prior to the starting order;

transmitting (S402), to a User Equipment, UE, in a downlink control channel on a first downlink carrier, the downlink control message carrying the starting order; and

transmitting (S404) the upcoming downlink control message to the UE on the first downlink carrier.

2. The method of claim 1 wherein the upcoming downlink control message occurs in the second manner based on the transmission of the downlink control message carrying the starting order.

3. The method of any of claims 1 to 2 further comprising:

indicating, in a downlink control message carrying a stopping order, whether any additional upcoming downlink control message will occur in the first manner;

transmitting, to the UE, in the downlink control channel on the first downlink carrier, the downlink control message carrying the stopping order;

transmitting the additional upcoming downlink control message to the UE on the first downlink carrier.

4. The method of claim 3 wherein the additional upcoming downlink control message occurs in the first manner based on the transmission of the downlink control message carrying the stopping order indicative of the additional upcoming downlink control message.

5. The method of any of claims 3 to 4 wherein the time between the downlink control message carrying the starting order and the downlink control message carrying the stopping order defines a transmission interval during which any upcoming downlink control message occurs in the second manner.

6. The method of any of claims 3 to 5 wherein the downlink control message carrying the starting order and the downlink control message carrying the stopping order are different.

7. The method of any of claims 1 to 6 wherein transmitting, in the downlink control channel, the downlink control message carrying the starting order comprises transmitting, to the UE, in a High Speed-Shared Control Channel, HS-SCCH, on the first downlink carrier, the downlink control message carrying the starting order.

8. The method of any of claims 3 to 7 wherein transmitting, in the downlink control channel, the downlink control message carrying the stopping order comprises transmitting, to the UE, in the HS-SCCH, on the first downlink carrier, the downlink control message carrying the stopping order.

9. The method of any of claims 1 to 8 wherein the radio network node operates in a High Speed Downlink Packet Access, HSDPA, network.

10. A radio network node adapted to:

indicate, in a downlink control message carrying a starting order, whether any upcoming downlink control message will occur in a second manner;

transmit, to a User Equipment, UE, in a downlink control channel on a first downlink carrier, the downlink control message carrying the starting order;

transmit one or more upcoming downlink control messages to the UE on the first downlink carrier.

1 1. The radio network node of claim 10, wherein the radio network node is

further adapted to operate according to the method of any of claims 2 to 9.

12. A computer program product comprising a non-transitory computer readable storage medium having computer readable program code embodied in the medium, the computer readable program code comprising:

computer readable program code to indicate, in a downlink control message carrying a starting order, whether an upcoming downlink control message will occur in a first manner or in a second manner;

computer readable program code to transmit, to a User Equipment, UE, in a downlink control channel on a first downlink carrier, the downlink control message carrying the starting order; and

computer readable program code to transmit one or more upcoming downlink control messages to the UE on the first downlink carrier.

13. The computer program product of claim 12, wherein the computer readable program code further comprises computer readable program code to operate according to the method of any of claims 2 to 9.

14. A method in a User Equipment, UE, the method comprising: receiving (S500), from a radio network node, a downlink control message carrying a starting order, the downlink control message being received in a downlink control channel on a first downlink carrier;

determining (S502), from the downlink control message carrying the starting order, whether any upcoming downlink control message will occur in a second manner; and

receiving (S504) one or more upcoming downlink control messages on the first downlink carrier.

15. The method of claim 14 wherein the upcoming downlink control message occurs in the second manner based on the reception of the downlink control message carrying the starting order.

16. The method of any of claims 14 to 15 further comprising:

receiving a downlink control message carrying the stopping order, in the downlink control channel on the first downlink carrier; and

receiving one or more additional upcoming downlink control messages on the first downlink carrier.

17. The method of claim 16 wherein the additional upcoming downlink control message occurs in the first manner based on the reception of the downlink control message carrying the stopping order.

18. The method of any of claims 16 to 17 wherein the time between the

downlink control message carrying the starting order and the downlink control message carrying the stopping order defines a transmission interval during which the upcoming downlink control message occurs in the second manner.

19. The method of any of claims 16 to 18 wherein the downlink control message carrying the starting order and the downlink control message carrying the stopping order are different.

20. The method of any of claims 14 to 19 wherein receiving, in the downlink control channel, the downlink control message carrying the starting order comprises receiving, in a High Speed-Shared Control Channel, HS-SCCH, on the first downlink carrier, the downlink control message carrying the starting order.

21. The method of any of claims 16 to 20 wherein receiving, in the downlink control channel, the downlink control message carrying the stopping order comprises receiving, in the HS-SCCH, on the first downlink carrier, the downlink control message carrying the stopping order.

22. The method of any of claims 14 to 21 wherein the radio network node operates in a High Speed Downlink Packet Access, HSDPA, network.

23. A User Equipment, UE, adapted to:

receive, from a radio network node, a downlink control message carrying a starting order, the downlink control message being received in a downlink control channel on a first downlink carrier;

determine, from the downlink control message carrying the starting order, whether an upcoming downlink control message will occur in a second manner; and receive one or more upcoming downlink control messages on the first downlink carrier.

The UE of claim 23, wherein the UE is further adapted to operate according to the method of any of claims 14 to 22.

A computer program product comprising a non-transitory computer readable storage medium having computer readable program code embodied in the medium, the computer readable program code comprising:

computer readable program code to receive, from a radio network node, a downlink control message carrying a starting order, the downlink control message being received in a downlink control channel on a first downlink carrier;

computer readable program code to determine, from the downlink control message carrying the starting order, whether an upcoming downlink control message will occur in a second manner;

computer readable program code to receive the upcoming downlink control message on the first downlink carrier. 26. A computer program product as in claim 25, wherein the computer readable program code further comprises computer readable program code to operate according to the method of any of claims 14 to 22.