WO2016201632A1

WO2016201632A1 - Multicarrier scheduling

Info

Publication number: WO2016201632A1
Application number: PCT/CN2015/081620
Authority: WO
Inventors: Rui Fan; Shaohua Li; Jinhua Liu; Qianxi Lu; Xinghua SONG
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2015-06-17
Filing date: 2015-06-17
Publication date: 2016-12-22

Abstract

The invention relates to a method for operating a mobile entity (200) in a mobile communications network, the mobile entity being configured for carrier aggregation with a plurality of component carriers, the method comprising. A group indicator is obtained associated with at least one of the component carriers, wherein the group indicator indicates a number of said plurality of component carriers. Furthermore, a subset of component carriers is determined from the plurality of component carriers which correspond to scheduled component carriers for the mobile entity based on the group indicator.

Description

Multicarrier scheduling

Technical Field

The invention relates to a method for operating a mobile entity, to a method for operating a network node and the corresponding mobile entity and network node, both the mobile entity and the network node being configured to use carrier aggregation. The invention furthermore relates to a system comprising the mobile entity and the network node, to a computer program and a computer program product.

Background

The use of LTE (Long Term Evolution) Carrier Aggregation (CA) , introduced in release 10 and enhanced in release 11 offers means to increase peak data rates, system capacity and user experience in a mobile communications network by aggregating radio resources from multiple carriers. The carriers may reside in the same band (intraband carrier aggregation) or different bands (interband carrier aggregation) and for the case of interband TDD (Time Division Duplex) carrier aggregation, different carriers can be configured with different uplink/downlink (UL/DL) configurations. Each aggregated carrier is referred to as a Component Carrier, CC. In release 12, carrier aggregation between TDD and FDD (Frequency Division Duplex) serving cells is introduced to support a mobile entity (UE) connecting to both cells simultaneously.

When carrier aggregation is used, there is a number of serving cells, one for each component carrier. Furthermore, the coverage of the serving cells may differ as different frequency bands may experience different path loss. Compared to single carrier aggregation, a mobile entity operating with carrier aggregation has to report feedback for more than one downlink component carrier. However, a mobile entity does not need to support downlink and uplink carrier aggregation simultaneously. For instance, the first release of CA capable mobile entities on the market only supports downlink carrier aggregation but not uplink carrier aggregation. This is also the underlying assumption in the 3GPP RAN 4 (Radio Access Network) standardization. Therefore, an enhanced UL control channel, i.e. PUCCH (Physical Uplink Control Channel) format 3, was introduced for carrier aggregation during release 10 timeframe. However, in order to support more component carriers, in release 13 the uplink control channel capacity becomes a limitation.

The fast uptake of LTE in different regions of the world shows both that demand for wireless broadband data is increasing, and that LTE is an extremely successful platform to meet that demand. Existing and new spectrum licensed for exclusive use by IMT (International Mobile Telecommunications) technologies will remain fundamental for providing seamless coverage, achieving the highest spectral efficiency, and ensuring the highest reliability of cellular networks through careful planning and deployment of high-quality network equipment and devices.

To meet ever increasing data traffic demand from users, in particular, in concentrated high traffic buildings or hot spots, more mobile broadband bandwidth will be needed. Fig. 1 provides a more detailed view of an unlicensed frequency spectrum in the 5 GHz range available in selected countries or regions around the world. The unlicensed spectrum is more and more considered by cellular operators as a complimentary tool to augment their service offering. While unlicensed spectrum can never match the qualities of the licensed spectrum, solutions that allow an efficient use of the unlicensed spectrum as a complement to licensed developments are needed.

Therefore, it has been agreed to study Licensed Assisted Access (LAA) technologies in 3GPP. This LAA framework builds on the carrier aggregation solutions introduced in release 10 LTE to access the additional bandwidth in the unlicensed band.

With carrier aggregation, there are a number of serving cells, one for each component carrier. The connection to the mobile communications network is handled by one cell, the primary serving cell (with a primary carrier) , whereas the other component carriers are referred to as secondary component carriers served by a secondary cell.

This is illustrated in Fig. 2, where a mobile entity/UE 10 is shown as being connected to the primary cell with a primary carrier 20 and a secondary carrier 30. The primary cell retains the exchange of essential control messages and also provides an always available robust spectrum for real-time or high-value traffic. The primary cell also provides mobility handling and management for the mobile entity 10 via the licensed band LTE radio access network with wide coverage. The aggregated secondary cells in the unlicensed band, when available, can be utilized as bandwidth booster to serve, e. g. best effort traffic. The LAA secondary cell may operate in a downlink-only mode or may operate with both uplink and downlink traffic as shown in Fig. 2.

As illustrated above, LAA has attracted a lot of interest in extending the LTE carrier aggregation feature towards capturing the spectrum opportunities of unlicensed spectrum, e.g. in the 5 GHz band. WLAN operating in the 5 GHz band nowadays already supports 80 MHz in the field and 160 MHz is to follow in Wave 2 deployment of IEEE 802.11 ac. At the same time, there are also other frequency bands, such as 3.5 GHz, where aggregation of more than one carrier on the same band is possible, in addition to the bands already widely in use for LTE. Enabling the utilization of at least similar bandwidths for LTE in combination with LAA as IEEE 802.11 ac Wave 2 will support calls for extending the carrier aggregation framework to support more than 5 carriers. The extension of the carrier aggregation framework beyond 5 carriers was approved to be one work item for LTE release 13. The objective is to support up to 32 carriers in both uplink and downlink, where most carriers would be unlicensed carriers.

In LAA, multiple unlicensed component carriers are utilized. These CCs are shared with the WiFi technology. Since WiFi occupies a bandwidth of 20, 40, 80 or 160 MHz depending on the WiFi version, the mobile communications network LAA competes for resources with WiFi. When the LAA system is succeeding the contention, the latter would get the available bandwidth of 20, 40, 80 or 160 MHz

One issue is how to monitor the scheduling information at the mobile entity when several CCs are available for transmission. Since the resource contention result is not predictable, the CC to transmit scheduling information cannot be fixed, as it is possible that the fixed CC may be occupied by another transmission technology using the same frequency such as WiFi. It would then not be possible to send scheduling information even other CCs may be available. As a consequence, a mobile entity has to monitor and decode the scheduling information on all component carriers. Thus, the scheduling information detection complexity is very high. An alternative solution would be to transmit a scheduling information on a licensed carrier on which the mobile entity performs grant monitoring. However, cross-carrier scheduling is an optional feature which may not be supported by all mobile entities. On the other hand, there are also some practical challenges which make cross-carrier scheduling not applicable. By way of example, in a macro cell (licensed spectrum) and RRH deployment in the unlicensed spectrum, the LAA function is performed in RRH (Remote Radio Head) while the scheduling grant is sent from the macro cell via PDCCH (Physical Downlink Control Channel) . This is technically impossible due to an overlap between the LAA and scheduling grant.

The above-mentioned problem not only exists in unlicensed CCs but in all CA scenarios in which it cannot be determined in advance which carrier will carry scheduling information.

Accordingly, a need exists to improve the detection of scheduling information in an environment where carrier aggregation is used.

Summary

This need is met by the features of the independent claims. Further aspects are described in the dependent claims.

According to one aspect, a method for operating a mobile entity in a mobile communications network is provided, wherein the mobile entity is configured for carrier aggregation with a plurality of component carriers. According to one step of the method, a group indicator is obtained associated with at least one of the component carriers, wherein the group indicator indicates a number of the plurality of component carriers. Furthermore, a subset of component carriers is determined from the plurality of component carriers which correspond to scheduled component carriers for the mobile entity based on the group indicator.

The group indicator received at a mobile entity in association with one of the component carriers helps the mobile entity to determine the scheduled component carriers. With the knowledge of the scheduled component carriers, the search for scheduling information at the mobile entity can be reduced when one component carrier carries scheduling information for several component carriers, here the subset of component carriers, a search for scheduling information can be avoided in the scheduled component carriers when scheduling information was found in one of the component carriers of the scheduled component carriers. The scheduled component carriers are the component carriers from the plurality of component carriers for which scheduling information is present in one of the component carriers. Thus, the scheduled component carriers are the component carriers for which scheduling assignment is found in one of the component carriers. The mobile entity knows for the scheduled component carriers where user data for the mobile entity can be found.

With the knowledge of the group indicator and the said one component carrier with which the group indicator is associated, the mobile entity can deduce the scheduled component carriers and can carry out the search for scheduling information in other component carriers taking this knowledge into account.

The step of obtaining the group indicator can optionally include the step of obtaining scheduling information comprising the group indicator, wherein the scheduling information is associated with the determined subset of component carriers. This association of the scheduling information with the determined subset of component carriers means that the scheduling information is valid for the determined subset of component carriers.

Furthermore it is possible that the different component carriers have different component carrier priorities. The component carrier priority represents a likelihood that a component carrier carriers scheduling information for the scheduled component carriers. The higher the component carrier priority is, the higher the likelihood is that a component carrier carries scheduling information for multiple other component carriers.

One component carrier of the subset of component carriers may carry the scheduling information comprising the group indicator valid for the subset of component carriers with the scheduled component carriers corresponding to the subset of component carriers which are scheduled by the scheduling information in said one component carrier.

The component carriers as described above can be accessed based on contention-based access. In other words, the network node or network nodes responsible for scheduling may have to listen on the corresponding component carrier before they can talk on this component carrier (listen before talk approach) . Thus, the component carriers can be unlicensed component carriers where the mobile network competes with other transmission technologies for the available transmission resources, e.g. WiFi. However, it should be understood that the application is not restricted to the use of unlicensed component carriers. The features described above or described in more detail below may furthermore be used in the licensed spectrum of component carriers.

The invention furthermore relates to the corresponding mobile entity configured for carrier aggregation, the mobile entity comprising at least one processing unit configured to obtain the group indicator associated with at least one of the component carriers, the group indicator indicating a number of said plurality of component carriers. Furthermore, the at least one processing unit is configured to determine a subset of the plurality of component carriers which correspond to the scheduled component carriers for the mobile entity based on the group indicator.

The invention furthermore relates to a method for operating a network node configured to use carrier aggregation with a plurality of component carriers in a mobile communication network. According to one step of the method, a group indicator is obtained associated with at least one of the component carriers wherein the group indicator indicates a number of the plurality of component carriers and determines a subset of component carriers from the plurality of component carriers which correspond to the scheduled component carriers for the mobile entity. Furthermore, the group indicator associated with said one component carrier is transmitted to the mobile entity. The network node can be the network node such as eNB responsible for the scheduling of mobile entities in the mobile communications network.

The invention furthermore relates to the corresponding network node comprising at least one processing unit configured to operate as mentioned above. The at least one processing unit is configured to obtain the group indicator associated with the at least one of the component carriers, the network node furthermore comprising a transmitter configured to transmit the group indicator associated with said one component carrier to the mobile entity.

According to a further aspect, a system is provided comprising a mobile entity and a network node as mentioned above.

Furthermore, a computer program and a computer program product comprising program code to be executed by at least one processing unit of the mobile entity or the network node is provided, wherein execution of the program code causes the control entity or the network node to perform the step discussed above or discussed in further detail below.

Details of embodiments will become apparent from the following detailed description when read in conjunction with the accompanying drawings, in which like reference numerals refer to like elements.

Brief Description of the Drawings

Fig. 1 is a schematic view of an unlicensed spectrum of transmission resources available in different parts of the world.

Fig. 2 schematically illustrates an overview over licensed assisted access.

Fig. 3 schematically illustrates the usage of component carriers in a WiFi system.

Fig. 4 illustrates a state diagram of a network node using a group indicator for the transmission of scheduling information.

Fig. 5 schematically shows a state diagram of a mobile entity searching for scheduling information in different component carriers taking into account the group indicator.

Fig. 6 shows a flowchart illustrating how a mobile entity searches for scheduling information and the group indicator depending on a component carrier’s priority.

Fig. 7 schematically illustrates the correlation of the different component carriers resulting in the indicated possible carrier groups.

Fig. 8 schematically shows examples of different data carrier groups built from the possible carrier groups based on the group indicator.

Fig. 9 schematically illustrated structures of the network node transmitting the scheduling information and the group indicator.

Fig. 10 schematically illustrates structures of a mobile entity receiving the scheduling information and the carrier group of the present invention.

Fig. 11 schematically illustrates a flowchart including the steps carried out at the mobile entity of Fig. 10 to determine scheduling information.

Detailed Description

In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. It is to be understood that the following description of embodiments is not to be taken in a delimiting sense. The scope of the invention is not intended to be limited by the embodiments described hereinafter or by the drawings which are to be taken as to be illustrative only.

The drawings are to be regarded as schematic representations and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose becomes apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling. A coupling between components may be established via a wired or a wireless connection. Functional blocks may be implemented in hardware, firmware, software or a combination thereof.

In the following, a method will be disclosed how multiple component carriers can be effectively scheduled. One application is the scheduling of multiple unlicensed component carriers in the LAA scenario. However, the invention may also be used in any other scenario where one component carrier which is not a predefined carrier carries scheduling information for multiple component carriers. The network node scheduling the different mobile entities such as an eNB may use a group indicator to effectively schedule different component carriers. Some of the component carriers can be given a higher priority to carry scheduling information whereas other component carriers are given a lower priority to carry scheduling information. As far as the mobile entity is concerned, the mobile entity starts to detect the scheduling information in a component carrier having a higher component carrier priority and if scheduling information and a group indicator indicating scheduled component carriers is detected, the mobile entity may start or may not start a detection of scheduling information in component carriers having a lower priority. The component carrier priority may be predefined within the mobile communication system. Furthermore, it is possible that the component carrier priority is defined by the network node distributing the scheduling information or by any other component of the mobile communications network. In still another option, the information about the different component carrier priorities may also be determined by the network node and the mobile entity together.

As will be described in further detail below, the complexity and the effort to detect scheduling information in a carrier aggregation environment where not a single predefined component carrier carries the scheduling information is reduced.

In the embodiments described below, the different component carriers are unlicensed carriers if not specified otherwise. Furthermore, the description below uses a group of eight component carriers as an example, however, the invention can be used with any other number of component carriers. Furthermore, the solution described below works for both LAA, WiFi coexistence and LAA, LAA coexistence. For the mobile entity, it is not possible to know in advance which component carrier is used by the network node such as LTE eNB when the mobile communication system is sharing resources with another transmission technology such as WiFi. Nevertheless it is still possible to take advantage of how the other transmission technology uses the spectrum or the carrier.

Fig. 3 illustrates how carrier aggregation is applied in a WiFi system. As illustrated in Fig. 3, a spectrum from 5170 MHz to 5330 MHz is used in the illustrated example. With this 160 MHz, there are eight component carriers of 20 MHz with the index from 0 to 7. When the resource is used by the WiFi technology and if the WiFi receiving entity only supports operating 20 MHz, then any of the eight component carriers could be occupied by WiFi depending on the competition results. When the WiFi terminal supports operating 40 MHz, then the component carrier occupied by WiFi is CC0 and CC1 or CC2 and CC3 or CC4 and CC5 or CC6 and CC7. Another combination of component carriers is not allowed. If the WiFi terminal supports an operation with a bandwidth of 80 MHz, then the CC occupied by WiFi is CC0, CC1, CC2 and CC3 or CC4, CC5, CC6 and CC7. Other combinations are not allowed. Finally, if the WiFi terminal supports operating with a 160 MHz bandwidth, all CCs CC0-CC7 are occupied.

From the above discussion it can be deduced that the fact which CC is the first CC in a group has different implications. If CC0 is the first CC in a group, this could imply the following situations: a group of all eight CCs is occupied, a group of CC0-CC3 is occupied, a group of CC0 and CC1 is occupied or CC0 alone is occupied. If CC1 is the first CC in a group, this means that only of group of CC1 alone is occupied. Thus, different component carrier priorities can be assigned to different component carriers. The priority here means the order for a mobile entity to monitor possible scheduling information as the scheduling information is included into the CC with the highest priority as further explained in detail below.

Taking the example given above, the component carrier priority of all component carriers from a higher priority to a lower priority are as follows:

CC0, CC4, CC2, CC6, CC1, CC3, CC5, CC7.

When the mobile communications network succeeds to occupy all component carriers, scheduling information is transmitted on CC0. When the mobile communications network, e.g. the LTE eNB succeeds to occupy four CCs, scheduling information is transmitted on CC0 or CC4, depending on which group of CCs is available. When the network node of the mobile communications network succeeds to occupy two component carriers, scheduling information is transmitted on CC0, CC2, CC4 or CC6, depending on which group of CCs are available. Finally, when the network node succeeds to occupy one CC, then the scheduling information is transmitted on each corresponding component carriers.

As the different component carriers have different component carrier priorities concerning the fact whether a component carries scheduling information, the corresponding mobile entity can search for scheduling information in the different component carriers taking into account this component carrier priority. A mobile entity may be able to search for scheduling information in several component carriers at a time. This, however, is a power consuming task and depends on the capabilities of the mobile entity. Furthermore, it is possible that the mobile entity searches for the component carriers in one component carrier after the other. When the mobile entity has found scheduling information for several component carriers in one component carrier, it can stop searching for scheduling information for the component carriers for which scheduling information was found in one of the component carriers. The mobile entity can thus at least complete the search for scheduling information in a priority component carrier having the highest component carrier priority among the plurality of component carriers.

In the example mentioned above, although the mobile entity may still need to monitor all eight CCs, but when it decodes scheduling information, it first decodes the scheduling information on CC0, then CC4 etc. According to the decoding results on the higher priority component carrier, the mobile entity may deduce that it is still necessary for it to decode component carriers on a lower priority component carrier. By way of example, if scheduling information on CC0 indicates that all eight component carriers are occupied, it is not necessary for the mobile entity to decode the scheduling information on the remaining component carriers anymore. As a consequence, the decoding effort and complexity can be reduced.

The search for scheduling information can be further optimized when a group indicator is used. The group indicator can indicate which of the component carriers are scheduled by a scheduling information comprised in one of the component carriers. Thus, the group indicator can indicate the number of the possible component carriers. This is explained on the following example. If, as in the example mentioned above, eight component carriers are possible, only different combinations of component carriers are possible as discussed above. A first value of the group indicator may indicate that one carrier is scheduled, whereas a second value may indicate that two of the component carriers of the possible component carriers are scheduled. A third value of the group indicator may indicate that four component carriers are scheduled and another number, the fourth number, may mean that all eight component carriers are scheduled. This means that the scheduling information contained in one of the component carriers comprising the group indicator is valid for all the component carriers indicated by the group indicator. In the example mentioned above of eight possible component carriers, a two-bit value for specifying the group indicator may be enough. In the example above, a first group indicator, GI ＝ 00 may mean that one CC is scheduled, GI ＝ 01 can mean that two CCs are scheduled, the GI ＝ 10 can mean that four CCs are scheduled and the GI ＝ 11 can mean that eight CCs are scheduled.

The mobile entity detects Downlink Control Information (DCI) for determining the scheduling information. If the mobile entity detects downlink control information with scheduling information at CC0 and determines that the included group indicator GI ＝ 11, the mobile entity knows that all eight CCs are scheduled starting from CC0, i.e. CC0 up to CC7 are all scheduled. The mobile entity can thus deduce the scheduled component carriers based on the group indicator and based on the component carrier in which the scheduling information and the group indicator are included. Referring again to the example mentioned above, this would furthermore mean that the mobile entity would not continue to decode the DCI on CC1-CC7 anymore. Depending on the capabilities of the mobile entity, the mobile entity may have already started the search for scheduling information in these component carriers. Depending of the UE capabilities and other factor, such as the processing load, the mobile entity may also have not yet started to search for scheduling information in CC1-CC7. Based on the group indicator found in CC0, the mobile entity can either stop the search for scheduling information in CC1-CC7 when GI ＝ 11 was found in CC0, or it will not start the search for scheduling information. In the following, these two options will be referred to as discontinue. Thus, the mobile entity can discontinue the search for scheduling information in the component carriers indicated by the group indicator.

If the mobile entity detects downlink control information at CC0 and finds that the group indicator is 10 of the example mentioned above, then it knows that four component carriers are scheduled starting from CC0, i.e. CC0 up to CC3 are all scheduled and the mobile entity would not continue to decode the DCI on CC1-CC3 anymore. The mobile entity would then continue to decode the DCI on CC4. If the mobile entity detects the DCI on CC0 and finds that the group indicator indicates that two CCs are scheduled, it can be deduced that two CCs are scheduled starting from CC0, i.e. CC0 up to CC1 are all scheduled. In this example, the mobile entity would not continue to decode the DCI on CC1 anymore. The UE would continue to decode the DCI on CC4, CC2.

Fig. 4 indicates a state diagram summarizing the possibilities of a network node responsible for generating scheduling information. In a step S40 it is determined which of the component carriers are available for the mobile communications network. In the example given in Fig. 4, this is the network node competing on the unlicensed component carriers. When the network node is able to use the available component carriers, the number of occupied component carriers can be determined in step S41. Depending on the transmission requirements and on the demand of data to be transmitted to the mobile entity, the network node can determine how many of the component carriers are necessary for the transmission. If it is decided in step S41 that one component carrier is enough, the group indicator GI is set such that the group indicator indicates that the scheduling information associated with the group indicator is valid for a single component carrier (step S42) . Based on the example given above, it would mean that the group indicator GI is set to GI ＝ 00. In step S43 the downlink control information including the scheduling information and the group indicator is sent to the mobile entity on the corresponding component carrier to which the information relates. If it is determined in step S41 that two component carriers are needed for the transmission, the group indicator is set to the corresponding value in step S44 for the downlink control information with the scheduling information and the group indicator is transmitted with either CC0, CC2, CC4 or CC6, depending on which component carriers are used for the transmission (step S45) . If the result of step S 41 is that four component carriers are needed, the group indicator is set in step S46 to the corresponding value and the scheduling information including the group indicator is either sent on CC0 or CC4, depending on which of the four component carriers are used. If the information is transmitted with CC4, the mobile entity knows that component carriers CC4-CC7 will be scheduled as indicated by the scheduling information in CC4 of step S47. If it is determined in step S41 that all eight component carriers are needed as transmission resources, the corresponding group indicator is set in step S48 to indicate that the scheduling information refers to eight component carriers. In step S49 the corresponding DCI including the scheduling information and the group indicator is then transmitted in connection with CC0 to the mobile entity.

The scheduling information received on the component carrier including the group indicator is valid for all of the scheduled component carriers. This means that a Modulation Coding Scheme (MCS) , a Resource Block (RB) information present on one of the component carriers is valid for the other scheduled component carriers indicated by the group indicator. The group indicator is transmitted in association with one of the component carriers, i.e. on the scheduled component carrier with the highest priority. Depending on the number of component carriers in one group, a two-bit, three-bit or four-bit value may be used to indicate the group indicator. By way of example, the existing CIF (Carrier Indicator Field) may be used so that the group indicator is sent as part of the CIF parameter. However, it should be understood that the group indicator may be transmitted to the mobile entity in another format or associated with other data transmitted to the mobile entity.

In connection with Fig. 5, a state diagram is explained in more detail which helps to understand how the mobile entity operates in dependence on the detected scheduling information and the detected group indicator. The diagram shown in Fig. 5 should not indicate a time sequence with which steps are carried out at the mobile entity. Fig. 5 helps to understand how the mobile entity carries out the search for scheduling information in dependence on the detected group indicator.

As discussed above, the mobile entity will start the search for scheduling information and the search for a group indicator in a priority component carrier having the highest component carrier priority among the plurality of component carriers. Thus, in step S50 the mobile entity starts to search for carrier information in CC0, CC0 corresponding to the component carrier with the highest component carrier priority. As discussed above in connection with Fig. 4, the group indicator, if present, is detected in step S51. The processing at the mobile entity if the group indicator is not detected in the component carrier with the highest priority will be discussed in further detail below in connection with Fig. 6. The easiest processing case is shown in the right part of Fig. 5 which occurs when the detected group indicator indicates that all component carriers are scheduled by the scheduling information found in CC0. The group indicator with the value GI ＝ 11 of the example discussed above indicates that all eight component carriers are scheduled component carriers. Thus, there is no need to search for scheduling information in other component carriers and the mobile entity knows where in the component carriers downlink data are received as the MCS and RB information is valid for all the scheduled component carriers. Thus, the mobile entity can in step S52 directly decode the downlink data transmitted to the mobile entity in the eight component carriers in the resource parts indicated by the scheduling information.

If it is determined in step S51 that the group indicator indicates that four of the eight component carriers are scheduled, the mobile entity can decode that data on CC0-CC3 in step S53. However, no information is provided for CC4-CC7. For this reason, the search for scheduling information in CC4 is carried out in step S54. Depending on the value of the group indicator found in CC4, the search for scheduling information continues or not. In step S55 the group indicator is determined. If it is determined in step S55 that the group indicator indicates that a single component carrier is scheduled, the corresponding data can be decoded on CC4 in step S56. This however means that if only a single data carrier is scheduled on CC4, the search for scheduling information has to continue in CC5 (step S57) . If scheduling information is present the corresponding data may be decoded on CC5 in step S58.

Returning back to step S55, the group indicator may indicate that two component carriers are scheduled in CC4. Thus, user data can be decoded in CC4 and CC5 in step S59 based on the scheduling information found in CC4. At the same time, the search has to continue in step S60 in CC6. In step S61 the group indicator in CC6 is determined. If the group indicator is indicating that two scheduled component carriers are present, the data can be decoded in step S62 on CC6 and CC7. If it is determined in step S61 that one component carrier is scheduled, the data is decoded on CC6 in step S63. If at S61, no scheduling information is detected, it has to continue the detection in CC7 in step S64 where the scheduling information may be found in CC7. Based on this scheduling information, the data can be decoded on CC7 in step S65.

Referring back to step S55, it is detected that the group indicates that four component carriers are scheduled, the corresponding data is decoded on CC4-CC7 in step S66.

Referring back to step S51, if the group indicator indicates two component carriers are scheduled, the data can be decoded on CC0 and CC1 in step S67. Furthermore, it is possible that scheduling information is provided on CC2 so that in step S68 scheduling information is detected on CC2. The corresponding group indicator is determined in step S69. If the group indicator indicates on CC2 that two component carriers are scheduled the corresponding user data can be decoded in step S70 on CC2 and CC3. If the group indicator indicates that a single component carrier is scheduled on CC2, the data can be decoded on CC2 alone in step S71 and possible scheduling information has to be detected in step S72 on CC3. Based on the detected scheduling information on CC3, the corresponding user data can be detected in step S73. If it is detected that the group indicator in step S51 indicates that two component carriers are scheduled, the search for scheduling information has to be continued in step S54 and the search for scheduling information in CC4-CC7 has to be carried out as discussed above. Last but not least, in step S51 if it is detected that the group indicator in CC0 indicates that a single component carrier is scheduled, the data can be decoded in step S74 on CC0. Furthermore, scheduling information has to be detected in step S75, if present, and the corresponding decoding of user data on CC1 can be carried out in step S76. As indicated by the connections from GI ＝ 00 to steps S68 and S54 the search has to be continued in CC4 and CC2 as discussed above.

Referring to Fig. 6 and based on the discussion of Fig. 5, the operating steps carried out at the mobile entity can be summarized as follows. The method starts in step S80 and in step S81 downlink control data is received. The search for scheduling information is at least carried out in step S82 in the priority component carrier having the highest priority among the plurality of component carriers which are available and which may be the component carriers which are accessed based on the contention based access meaning that the mobile communications network may not be the only transmission technology using the corresponding component carriers. In the example above, this is component carrier CC0. In step S83 it is then determined whether scheduling information and the group indicator can be found in the priority component carrier. If scheduling information and the group indicator is detected, the group indicator is identified in step S84. In the example mentioned above, the group indicator could indicate that either one, two, four or eight component carriers are scheduled. In step S85 the corresponding scheduling information valid for the scheduled component carriers is determined and user data may be decoded based on the information provided by the scheduling information. In step S86 the search for scheduling information is discontinued in the scheduled component carriers indicated by the group indicator. As a valid scheduling information was found for the scheduled component carriers, the further search for scheduling information can be avoided. Referring back to step S83, if it is detected that no scheduling information was found in the priority component carrier, the search for scheduling information is continued in the component carrier with the next component carrier priority. In the example given above, if no scheduling information was found in CC0, the search for scheduling information is continued in CC4. If scheduling information is found in step S87 in the component carrier with the next highest priority, the method continues with the identification of the group indicator and the corresponding search in the other component carriers in dependence on the identified group indicator as discussed above in connection with steps S84-86.

Furthermore, if a group indicator has been found in either the component carrier with the highest or the second highest priority, after step S86 the system continues to search for scheduling information in the component carrier with the next priority which is not yet scheduled. If such a component carrier does not exist, the method can go via step S88 to step S89 or directly to step S89 (not shown) , where it is checked whether all component carriers are searched. If this is the case, the method ends in step S90. If not, the search is continued on the component carrier with the next priority. Method steps S87-89 are carried out as long as unscheduled component carriers exist.

From the above description of Fig. 3-6 some general conclusions can be drawn.

When the mobile entity obtains the group indicator, is obtains a scheduling information comprising the group indicator, the scheduling information being associated with the determined subset of component carriers. The scheduling information is valid for the determined subset of the component carriers and the group indicator contained in one of the component carriers determines that number of component carriers and thus determines the scheduled component carriers in dependence on the fact which component carrier carries the group indicator.

Thus, the mobile entity can search for the group indicator in the plurality of component carriers in an order based on a component carrier priority. The search for the group indicator comprises the searching in a priority component carrier having the highest component carrier priority among the plurality of component carriers. If the group indicator is detected in the priority component carrier, searching for the group indicator is not continued in the subset of component carriers indicated by the group indicator. As discussed above, when the group indicator is detected in CC0, the search for scheduling information is not continued in the other component carriers depending on the number indicated by the group indicator. Not continued means here that the search is either not started or not completed in the other component carriers if the search was already started. If however, the group indicator is not detected in the plurality of component carriers, searching for the group indicator is continued in the component carrier among the plurality of component carriers with the second highest priority. Applied to the example above, if the scheduling information in the group indicator is not found in CC0, the search is continued in CC4 as being the component carrier with the second highest priority.

Furthermore, as could be deduced from above, the plurality of component carriers may be correlated with each other so that only predefined combinations of component carriers are allowed for carrier aggregation. Each allowed combination of component carriers can build a corresponding possible carrier group, a data carrier group is generated and contains the scheduled component carriers of a possible carrier group indicated by the group indicator and one component carrier of the data carrier group carries the group indicator for the scheduled component carriers of the data carrier group. As discussed above, it is the component carrier of the data carrier group having the highest priority among the component carriers of the data carrier group which carries the scheduling information.

The possible carrier groups and data carrier groups are further explained in connection with Fig. 7 and 8. Fig. 7 shows the different possible carrier group using the example of eight component carriers in total. A possible carrier group contains all the component carriers from CC0-CC7 so that a possible carrier group 81 exists including all the component carriers. This possible component carrier becomes a data carrier group if the group indicator in CC0 indicates that all eight component carriers are scheduled by the scheduling information found in CC0. However, in dependence on the combination another possible carrier group for CC0 exists, namely CC0-CC3 as possible carrier group 82. Furthermore, the possible carrier group CC0, CC1 indicated by possible carrier group 84 is possible or CC0 as indicated by carrier group 88a.

The scheduled component carriers can be determined by the mobile entity based on the group indicator and based on the component carrier carrying the group indicator. By way of example, if CC0 carries the group indicator indicating two component carriers, the scheduled component carriers are CC0 and CC1, whereas when CC4 carries the same group indicator the scheduled component carriers are CC4 and CC5.

In addition, CC4-CC7 may be a further possible carrier group 83. Another combination of carrier groups is CC2, CC3 as possible carrier group 85 or CC4, CC5 as possible carrier group 86 or CC6, CC7 as possible carrier group 87. Furthermore, the different single carrier groups 88a-88h exist. In connection with Fig. 8 in dependence on the group indicator contained in one of the carriers, a data carrier group is generated. The data carrier group contains at most the number of component carriers of a possible carrier group. Furthermore, the higher the priority of the component carrier in a possible carrier group is, the higher the number of data carrier groups is. By way of example, for CC0 a data carrier group can correspond to the possible carrier group 81, to the

possible carrier group

82, 84 or 88a.

Fig. 8 now shows different data carrier groups depending on the group indicator and depending on the fact on which component carrier the group indicator is present. By way of example, if the group indicator GI indicates on carrier CC0 that the scheduling information relates to four component carriers, the mobile entity can deduce that the scheduling information is valid for CC0-CC3. Thus, a data carrier group 91 is built. Another data carrier group starting at CC0 is data carrier group 92 which is generated when CC0 carries the group indicator that two component carriers are scheduled, thus CC0 and CC1. Based on the same scheme, the

data carrier groups

93 and 95 shown in Fig. 8 are generated. Summarizing, the allowed combinations of component carriers built the different possible carrier groups shown in Fig. 7 and the group indicator together with the component carrier carrying the group indicator determine the corresponding data carrier group, the data carrier group containing the scheduled component carriers of the possible carrier group.

Obtaining the group indicator can comprise the step of searching for the group indicator in the component carrier of the possible carrier group having the highest priority among the component carriers of the possible carrier group. If the group indicator is detected in the component carrier of the possible carrier group having the highest priority among the component carriers of the possible carrier group, searching is not continued in remaining component carriers of the data carrier group indicated by the group indicator. Applied to the example shown in Fig. 8, if the group indicator 10 is found in CC0, the search for the scheduling information is at least carried out in CC0 and if the group indicator is found, the search for scheduling information is discontinued, i.e. not even started or stopped in CC1, CC2 and CC3.

Furthermore, it can be checked whether other component carriers among the plurality of component carriers not included in the data carrier group exist. If this is the case, the search for scheduling information is continued or completed in the component carrier among the other component carriers having the highest priority among the other component carriers. Applied to the example above, if CC0 carries a group indicator of GI ＝ 11 this means that all component carriers are scheduled so that no search is necessary as no other component carriers not included in the data carrier group exist. If however, the group indicator is 10 in CC0, it can be deduced that other component carriers exist, namely CC4-CC7. The search for the scheduling information is then at least carried out in CC4 as this is the highest component carrier priority among the other component carriers CC4-CC7.

This furthermore means that if the group indicator is detected in the component carrier among the other component carriers having the highest priority among the other component carriers, searching for the group indicator is not continued or completed in the remaining component carriers of the data carrier group to which the component carrier among the remaining component carriers having the highest priority among the other component carriers belongs. When applying this statement to the example above, if the group indicator GI ＝ 10 is found in CC4, with CC4-CC7 being the component carriers, the searching for the group indicator is not continued in the component carriers given by the group indicator found in CC4. If the group indicator is 10 in CC4, the search for scheduling information can be terminated, and if the indicator is GI 01, the search has not to be continued or carried out in CC5 as CC5 is also scheduled by the scheduling information contained in CC4.

As far as the network node concerning the group indicator associated with at least one of the component carriers is concerned, the network node may furthermore generate scheduling information for the mobile entity and the group indicator and may transmit the scheduling information associated with the group indicator to the mobile entity. Furthermore, the group indicator may be associated with one of the scheduled component carriers wherein the group indicator is transmitted to the mobile entity associated with said one scheduled component carrier. As discussed above, the different component carriers are correlated with each other and the scheduling information and the group indicator can be included into the component carrier of the data carrier group having the highest priority among the component carriers of the data carrier group. Applied to the example above, if the scheduled component carriers are CC0-CC4, the scheduling information with the group indicator is included in CC0.

Fig. 9 illustrates exemplary structures which may be used for implementing the network node transmitting the scheduling information and the group indicator to the mobile entity, whereas Fig. 10 illustrates exemplary structures of the corresponding mobile entity. The network node shown in Fig. 9 may be eNB 100. The network node comprises an interface or input/output unit 110, with a transmitter 111 and a receiver 112. The interface 110 can be utilized for sending control information or user data to other entities inside or outside the communications network, e.g. the mobile entity 200 discussed below in connection with Fig. 10.The receiver 112 symbolizes the possibility of the network node 100 to receive control information or user data from other nodes inside or outside the mobile communications network. The interface 110 can operate in accordance with the different interfaces needed for communication with different other nodes.

A processing unit 120 coupled to the interface 110 and coupled to a memory 130 is provided. The processing unit 120 comprising one or more processors is responsible for the operation in which the eNB or network node 100 is involved. The processing unit can carry out instructions stored in memory 130, wherein the memory may include a read-only memory, a random access memory, a mass storage or the like. The memory 130 includes suitable configured program code to be executed by the processing unit 120 so as to implement the above-described functionalities of the network node 100. In particular, the memory may include various program code modules for the network node to perform processes as described above in connection with Fig. 5. The processing unit 120 can inter alia generate scheduling information for different mobile entities, can generate the group indicator and can associate the group indicator with the component carrier of a data carrier group having highest component carrier priority.

Fig. 10 is a schematic representational view of the corresponding mobile entity 200. The mobile entity 200 comprises an interface or input/output unit 210 with a transmitter 211 and a receiver 212, the transmitter 211 symbolizing the possibility to transmit control information or user data to other entities inside or outside the network, the receiver 212 symbolizing the possibility to receive control information to the data from other nodes, mobile entities inside or outside the mobile communications network. A processing unit 220 comprising one or more processors is responsible for the operation of the mobile entity. The processing unit 220 can carry out program code stored in memory 230. Different program code may be provided, which, when carried out by the processing unit 220, implement the above-described functionalities of the mobile entity 200. The processing unit 220 may be designed to operate the mobile entity in such a way that especially the steps discussed above in connection with Fig. 5 and 6 are carried out. Furthermore, a computer program may be provided implementing the functionalities of the mobile entity or of the network node, e. g. in the form of a physical medium storing the program code and/or other data to be stored in a memory such as

memory

230 or 130, or by making the program code available for download or by streaming.

The mobile entity 200 can furthermore comprise a display 240 and a human machine interface 250, the display 240 being used to display any piece of information, the human machine interface 250 being provided for the interaction of the user of the mobile entity 200.

It is to be understood that the structures illustrated in Fig. 9 and 10 are merely schematic and that the network node 100 and the mobile entity 200 may actually include further components which, for the sake of clarity, have not been illustrated. Also it is to be understood that the

memory

130 or 230 may include further types of program code modules, which have not been illustrated, e.g. program code modules for implementing known functionalities of the network node 100 or the mobile entity 200.

As described above, the invention provides an apparatus such as a mobile entity comprising a processing unit and a memory, said memory containing instructions executable by the processor whereby the mobile entity is operative to obtain a group indicator associated with at least one of the component carriers, the group indicator indicating a number of said plurality of component carriers. The apparatus is furthermore operative to determine a subset of component carriers from the plurality of component carriers which correspond to scheduled component carrier for the mobile entity based on the group indicator. The processor is capable of carrying out the steps of the mobile entity as discussed above in which the mobile entity is involved.

In the same way an apparatus such a network node is provided, the network node comprising a processor and a memory, the memory containing instructions executable by the processor whereby the network node is operative to obtain a group indicator associated with at least one of the component carriers, wherein the group indicator indicates a number of said plurality of component carriers and determines a subset of the component carrier from the plurality of component carriers which correspond to the scheduled component carriers for the mobile entity. Furthermore, it is operative to transmit the group indicator associated with said one component carrier to a mobile entity.

In other words, a mobile entity is provided which is configured for carrier aggregation with a plurality of component carriers, the mobile entity comprising a group indicator module configured to obtain a group indicator associated with at least one of the component carriers, the group indicator indicating a number of said plurality of component carriers. Furthermore, a subset determination module can be provided which determines a subset of the plurality of component carriers which correspond to scheduled component carriers for the mobile entity based on the group indicator. In the same way a network node configured to use carrier aggregation may be provided, the network node comprising a group indicator module obtaining the group indicator associated with at least one of the component carriers, wherein the group indicator indicates a number of the plurality of component carriers and determines a subset of component carriers from the plurality of component carriers which correspond to scheduled component carriers for a mobile entity. Furthermore, a transmitter module configured to transmit the group indicator associated with said one component carrier to the mobile entity can be provided.

Fig. 11 summarizes the steps carried out at the mobile entity. This starts in step S11. In step S12 the scheduling information and the group indicator are obtained by the mobile entity from one of the component carriers. In step S13 the scheduled component carriers are determined based on the group indicator and taking into account whether the component carrier on which the scheduling information with the group indicator is found. Based on the group indicator, a number of the plurality of component carriers is determined and using this number and the component carrier carrying the group information, the scheduled component carriers can be determined. Applied to the examples above, in step S13 when the group indicator is found to be 4 and when the component carrier carrying the group indicator is know, e.g. CC0 or CC4, the corresponding scheduled component carriers can be determined such as the scheduled component carriers CC0-CC3 or CC4-CC7.

The method ends in step S14.

It is to be understood that the examples and embodiments explained above are merely illustrative and susceptible to various modifications. Even though the examples were given for licensed or unlicensed component carriers, the image may be applied to any other component carrier for which a single component carrier carrying the scheduling information cannot be determined in advance.

With the above-described functionalities, the complexity for the determination of the scheduling information can be greatly reduced.

Claims

A method for operating a mobile entity (200) in a mobile communications network, the mobile entity being configured for carrier aggregation with a plurality of component carriers, the method comprising:

-obtaining a group indicator associated with at least one of the component carriers, wherein the group indicator indicates a number of said plurality of component carriers, and

-determining a subset of component carriers from the plurality of component carriers which correspond to scheduled component carriers for the mobile entity based on the group indicator.
The method according to claim 1, wherein obtaining the group indicator includes obtaining scheduling information comprising the group indicator, wherein said scheduling information is associated with the determined subset of component carriers.
A method according to claim 1 or 2, wherein obtaining the group indicator comprises searching for the group indicator in the plurality of component carriers in an order based on a component carrier priority.
The method according to an of claims 2 or 3, wherein one component carrier of the subset of component carriers carries the scheduling information comprising the group indicator valid for the subset of component carriers, wherein the scheduled component carriers correspond to the subset of component carriers which are scheduled by the scheduling information found in said one component carrier.
A method according to any of the preceding claims, wherein the component carriers are accessed based on contention based access.
The method according to any of claims 3 to 5, wherein searching for the group indicator comprises searching in a priority component carrier having the highest component carrier priority among the plurality of component carriers, wherein if the group indicator is detected in the priority component carrier, searching for the group indicator is not continued in the subset of component carriers indicated by the group indicator.
The method according to any of claims 3 to 6, wherein searching for the group indicator comprises searching in a priority component carrier having the highest component carrier priority among the plurality of component carriers, wherein if the group indicator is not detected in the priority component carrier, searching for the group indicator is continued in the component carrier among the plurality of component carriers having the second highest priority.
The method according to any of the preceding claims, wherein the plurality of component carriers are correlated with each other so that only predefined combinations of component carriers are allowed for carrier aggregation, each allowed combination of component carriers building a corresponding possible carrier group (81-88) , wherein a data carrier group (91-95) contains the scheduled component carriers of a possible carrier group indicated by the group indicator, wherein one component carrier of the data carrier group (91-95) carries the group indicator for the scheduled component carriers of the data carrier group,
The method according to claim 3 and 8, wherein obtaining the group indicator comprises searching for the group indicator in the component carrier of the possible carrier group (91-95) having the highest priority among the component carriers of the possible carrier group, wherein if the group indicator is detected in the component carrier of the possible carrier group (91-95) having the highest priority among the component carriers of the possible carrier group, searching is not continued in remaining component carriers of the data carrier group indicated by the group indicator.
The method according to claim 9, further comprising the steps of:

-checking whether other component carriers among the plurality of component carriers not included in the data carrier group (91-95) exist, wherein in the affirmative,

-searching is continued in the component carrier among the other component carriers having the highest component carrier priority among the other component carriers.
The method according to claim 10, wherein if the group indicator is detected in the component carrier among the other component carriers having the highest priority among the other component carriers, searching for the group indicator is not continued in the remaining component carriers of the data carrier group (91-95) to which the component carrier among the remaining component carriers having the highest priority among the other component carriers belongs.
A mobile entity (200) configured to operate in a mobile communications network and configured for carrier aggregation with a plurality of component carriers, comprising:

-at least one processing unit (220) configured to

-obtain a group indicator associated with at least one of the component carriers, wherein the group indicator indicates a number of said plurality of component carriers,

-determine a subset of said plurality of component carriers which correspond to scheduled component carriers for the mobile entity based on the group indicator.
The mobile entity (200) according to claim 12, wherein the at least one processing unit (220) , for obtaining the group indicator, is configured to obtain scheduling information comprising the group indicator, wherein the scheduling information is associated with the determined subset of said plurality of component carriers.
The mobile entity (200) according to claim 12 or 13, wherein the at least one processing unit (220) is configured to search for the group indicator in the plurality of component carriers in an order based on a component carrier priority for obtaining the group indicator.
The mobile entity (200) according to claim 14, wherein the at least one processing unit is configured to search for the group indicator in a priority component carrier having a highest component carrier priority among the plurality of component carriers, wherein if the group indicator is detected in the priority component carrier, the at least one processing unit (220) is configured not to continue the search for the group indicator in the subset of component carriers indicated by the group indicator.
The mobile entity (200) according to claim 14 or 15, wherein the at least one processing unit (220) is configured to search for the group indicator in a priority component carrier having a highest component carrier priority among the plurality of component carriers, wherein if the group indicator is not detected in the priority component carrier, the at least one processing unit is configured to continue the searching for the group indicator in the component carrier among the plurality of component carriers having the second highest priority.
The mobile entity (200) according to any of claims 12 to 16, wherein the plurality of component carriers are correlated with each other so that only predefined combinations of component carriers are allowed for carrier aggregation, each allowed combination of component carriers building a corresponding possible carrier group (81-88) , wherein a data carrier group (91-95) contains the scheduled component carriers of a possible carrier group indicated by the group indicator, wherein one component carrier of the data carrier group (91-95) carries the group indicator for the scheduled component carriers of the data carrier group, wherein the at least one processing unit (220) is configured, for obtaining the group indicator, to search for the group indicator in the component carrier of the possible carrier group having the highest priority among the component carriers of the possible carrier group, wherein if the group indicator is detected in the component carrier of the possible carrier group (91-95) having the highest priority among the component carriers of the possible carrier group, the at least one processing unit (220) is configured not to continue the search in remaining component carriers of the data carrier group indicated by the group indicator.
The mobile entity (200) according to claim 17, wherein the at least one processing unit (220) is configured to check, whether other component carriers among the plurality of component carriers not included in the data carrier group (91-95) exist, wherein in the affirmative, the at least one processing unit is configured to continue the searching in the component carrier among the other component carriers having the highest component carrier priority among the other component carriers.
The mobile entity (200) according to claim 18, wherein if the at least one processing unit (220) detects the group indicator in the component carrier among the other component carriers having the highest priority among the other component carriers, the at least one processing unit is configured not to continue searching for the group indicator in the remaining component carriers of the data carrier group (91-95) to which the component carrier among the remaining component carriers having the highest priority among the other component carriers belongs.
A method for operating a network node (100) configured to use carrier aggregation with a plurality of component carriers, in a mobile communications network, the method comprising:

-obtaining a group indicator associated with at least one of the component carriers wherein the group indicator indicates a number of said plurality of component carriers and determines a subset of component carriers from the plurality of component carriers which correspond to scheduled component carriers for a mobile entity (200) ,

-transmitting the group indicator associated with said one component carrier to a mobile entity (200) .
The method according to claim 20 further comprising

-generating scheduling information for the mobile entity (200) ,

-generating the group indicator,

-transmitting the scheduling information associated with the group indicator to the mobile entity (200) .
The method according to claim 20 or 21, further comprising

-associating the group indicator with one of scheduled component carriers, wherein the group indicator is transmitted to the mobile entity associated with said one scheduled component carrier.
The method according to claim 21 or 22, wherein the plurality of component carriers are correlated with each other so that only predefined combinations of component carriers are allowed for carrier aggregation, each allowed combination of component carriers building a corresponding possible carrier group (81-88) , wherein a data carrier group (91-95) contains the scheduled component carriers of a possible carrier group indicated by the group indicator, each data carrier group containing at most the component carriers of the corresponding possible carrier group, wherein the scheduling information and the group indicator is included into the component carrier of the data carrier group having the highest priority among the component carriers of the data carrier group (91-95) .
The method according to any of claims 20 to 23, wherein the scheduling information transmitted with one of the component carriers of the data carrier group is valid for all component carriers of the data carrier group (91-95) .
A network node (100) configured to use carrier aggregation with a plurality of component carriers in a mobile communications network, the network node comprising:

-at least one processing unit (120) configured to

-obtain a group indicator associated with at least one of the component carriers wherein the group indicator indicates a number of said plurality of component carriers and determines a subset of component carriers from the plurality of component carriers which correspond to scheduled component carriers for a mobile entity,

-a transmitter configured to transmit the group indicator associated with said one component carrier to the mobile entity.
The network node (100) according to claim 25, wherein the at least one processing unit (120) is configured to

-generate scheduling information for the mobile entity,

-generate the group indicator,

-transmit the scheduling information associated with the group indicator to the mobile entity.
The network node (100) according to claim 25 or 26, wherein the plurality of component carriers are correlated with each other so that only predefined combinations of component carriers are allowed for carrier aggregation, each allowed combination of component carriers building a corresponding possible carrier group (81-88) , wherein a data carrier group contains the scheduled component carriers of a possible carrier group indicated by the group indicator, each data carrier group containing at most the component carriers of the corresponding possible carrier group, wherein the at least one processing unit is configured to include the group indicator into the component carrier of the data carrier group having the highest priority among the component carriers of the data carrier group.
A system comprising a mobile entity (200) according to any of claims 12 to 19 and a network node (100) according to any of claims 25 to 27.
A computer program comprising program code to be executed by at least one processing unit (120, 220) of a mobile entity (200) or a network node (100) , wherein execution of the program code causes the control entity or the network node to perform the steps of a method according to any one of claims 1 to 11 or 20 to 24.
A computer program product comprising program code to be executed by at least one processing unit (120, 220) of a mobile entity or a network node, wherein execution of the program code causes the control entity or the network node to perform the steps of a method according to any one of claims 1 to 11 or 20 to 24.