WO2015032023A1

WO2015032023A1 - Power headroom report

Info

Publication number: WO2015032023A1
Application number: PCT/CN2013/082854
Authority: WO
Inventors: Chunhai Yao; Chunli Wu; Jari Olavi Lindholm
Original assignee: Nokia Siemens Networks Oy
Priority date: 2013-09-03
Filing date: 2013-09-03
Publication date: 2015-03-12

Abstract

The present invention relates to an apparatus, comprising at least one processor, and at least one memory for storing instructions to be executed by the processor, wherein the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus at least to perform: obtaining, at a user device, configuration information for at least two subframe sets for a serving cell, and determining for a power headroom report, at the user device, at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed, and the virtual power headroom being for at least one another subframe set.

Description

POW ER H EA D ROOM REPORT

Field

The present invention relates to power headroom report. In particular, some embodiments relate to an apparatus, method and program for power headroom report in dynamic TDD (Time Division Duplex) UL-DL (Uplink/Downlink) reconfiguration.

The present invention relates to the field of 3GPP (3^rd Generation Partnership Project) LTE-A (Long Term Evolution - Advanced) or beyond 4G/5G but is not limited thereto.

Background

With a new time division duplex (TDD) enhanced/extended interference management and traffic adaptation (elMTA) feature, eNB (enhanced NodeB) can change its uplink and/or downlink (UL/DL) configuration flexibly according to eNB traffic load in the buffer. At the same time the received interference from each subframe could be different depending on neighboring cells (UL/DL) configuration. According to the discussion in RAN I meeting, for the UL, the eNB will receive two kinds of interferences, one is from neighboring cell user devices, such as UEs, and another is from neighboring cell eNBs. Then two kinds of UL subframe could be seen from eNB, namely, fixed subframe and flexible subframe. In another case, subframe set of the UL power control can be based on received interference from neighboring cells, i.e. conflicting UL subframe or non-conflicting UL subframe. In short, two UL subframe sets can be configured by eNB in cell specific or user device specific manner. It is to be noted that subframe sets for UL PC (uplink power control) are configured independently from fixed/flexible subframe configuration because UL PC subframe set depends also on fixed/flex configuration in the neighbor cells.

In the case where seven UL/DL configurations can be reconfigured by the eNB, subframe 2 is a fixed UL subframe, and subframes 3, 4, 7, 8, and 9 could be flexible UL subframes. In RAN1#73 meeting, it was agreed that there are at least two subframe sets for enhanced UL power control with different power control parameters, i.e. P0 and alpha (a), where P0 is a cell specific parameter which defines target power level at the eNB. Alpha is a cell specific path loss compensation factor. Fig . 1 shows an example of the current TDD UL/DL configurations. In Fig . 1, D denotes a downlink subframe, U denotes an uplink subframe and S denotes a subframe for signaling . As can be seen in Fig . 1, there are seven UL/DL configurations and in each configuration, subframe 2 is a fixed UL subframe. Further, it can be seen that subframes 3, 4, 7, 8 and 9 are flexible UL subframes and some possible configuration examples are illustrated in Fig . 1. However, it is to be noted that the present invention is not limited to such a combination but it is applicable to any other feasible combination although not explicitly shown in Fig. 1.

It has been agreed that in UL, at least two subframe sets can be configured, and each subframe set should support separate open-loop power control parameters (i.e., PO and alpha (a)) and close-loop TPC (Transmit Power Control) commands.

In this regard, these parameters are applicable to different channels e.g., PUSCH (Physical Uplink Shared Channel) and SRS (Sounding Reference Symbol), and that a separate TPC (Transmit Power Control) command and accumulation is supported for each subframe set. Additionally, these parameters may also be applicable to PUCCH (Physical Uplink Control Channel).

An eNB may receive two kinds of interference, namely from flexible and fixed UL subframes. Uplink power control parameters PO and Alpha may be configured separately for each subframe set and TPC commands may be separately accumulated for the at least two subframe sets, which also means that the UL transmission power may significantly differ between different subframe sets. For example, in a flexible subframe, the eNB may receive neighboring eNB interference. In order to overcome this interference, the user device typically increases its UL transmission power. Thus, user device's power headroom report (PHR) shall be different for each subframe set, or otherwise the UL performance may be degraded. For the RAN1#74 meetings, there have been made some contributions [1] and [2] in order to address these PHR issues.

In a first contribution [1], several methods are proposed in this regard .

According to a first method disclosed in [1], if the above-mentioned event occurs in at least one subframe set, a user device will send PHRs of all subframe sets to the eNB. This method may require an additional specification work to design a new container (i.e., PHR MAC (Media Access Control) control element) including PHRs of multiple subframe sets of a single component carrier (CC).

According to a second method in [1], when the above-mentioned event occurs in at least one subframe set, a user device will send the representative PHR to the eNB. Here, for example, the representative PHR can be defined as the minimum value among PHRs of all subframe sets. In this example, it may also consider whether an user device reports the index of the subframe set which has the minimum PHR or not.

Further, according to a third method in [1], when the above-mentioned event occurs in at least one subframe set, a user device will send the PHR of the predefined subframe set (e.g ., set 1 in Section 3).

A further contribution according to reference [2] will be described in connection with Figs. 2 and 3. In the examples shown in Figs. 2 and 3, subframe set 1 consists of subframe 2 and subframe set 2 consists of subframes 3, 4, 7, 8 and 9.

In a first method according to reference [2] as illustrated in Fig . 2, the user device already gets the UL scheduling in subframe 8, but the user device will transmit both PHRs in subsequent subframe 2. In such a case, standardization and implementation for PHR storage and cancelation mechanisms might become complex. The PHR can be sent only when scheduling on both subframe sets has taken place.

In a second method according to reference [2] as illustrated in Fig . 3, if the PHR report is triggered, the user device then needs to wait for the UL grant to send the PHR. After that, the PHR timer will restart to the next PHR trigger. Actually this method will introduce two timers for two subframe set PH reports. Similar to the first method according to reference [2], standardization and implementation for PHR trigger and cancelation might become complex. However, in these methods, several technical aspects are left open, such as how to calculate power headroom reports (PHRs) for other than the first subframe sets and if only the minimum PHR is reported, the eNB is not able to carry out right scheduling for other than the first subframe sets, because the transmission power in the other subframe sets may already exceed the maximum allowable transmission power.

References:

[1] : Rl-133363, contribution for RAN1#74 meetings;

[2] : Rl-133538, contribution for RAN1#74 meetings;

[3] : TS 36.213

Summary

Thus, a need exists to provide options for improved or enhanced power headroom report.

According to an aspect of the present invention there is provided a method comprising : obtaining, at a user device, configuration information for at least two subframe sets for a serving cell, and determining for a power headroom report, at the user device, at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed and the virtual power headroom being for at least one another subframe set. According to another aspect of the present invention there is provided a method comprising : carrying out configuration of resources for at least two subframe sets for a serving cell, obtaining, at a node, a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained and the virtual power headroom being for at least one another subframe set, performing scheduling for the subframe sets based on the power headroom report.

According to another aspect of the present invention there is provided an apparatus, comprising at least one processor, and at least one memory for storing instructions to be executed by the processor, wherein the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus at least to perform : obtaining configuration information for at least two subframe sets for a serving cell, and determining for a power headroom report at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed and the virtual power headroom being for at least one another subframe set.

According to another aspect of the present invention there is provided an apparatus comprising : at least one processor, and at least one memory for storing instructions to be executed by the processor, wherein the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus at least to perform : carrying out configuration of resources for at least two subframe sets for a serving cell, obtaining a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained and the virtual power headroom being for at least one another subframe set, performing scheduling for the subframe sets based on the power headroom report.

According to another aspect of the present invention there is provided an apparatus comprising : means for obtaining configuration information for at least two subframe sets for a serving cell, and means for determining for a power headroom report at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed and the virtual power headroom being for at least one another subframe set.

According to another aspect of the present invention there is provided an apparatus comprising : means for carrying out configuration of resources for at least two subframe sets for a serving cell, means for obtaining a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained and the virtual power headroom being for at least one another subframe set, means for performing scheduling for the subframe sets based on the power headroom report.

According to another aspect of the present invention there is provided a user device comprising an apparatus as defined under certain of the above aspects. According to another aspect of the present invention there is provided node, server or host comprising an apparatus as defined under certain of the above aspects.

According to another aspect of the present invention there is provided a computer program product comprising code means adapted to produce steps of any of the methods as described above when loaded into the memory of a computer.

According to a still further aspect of the invention there is provided a computer program product as defined above, wherein the computer program product comprises a computer-readable medium on which the software code portions are stored.

According to a still further aspect of the invention there is provided a computer program product as defined above, wherein the program is directly loadable into an internal memory of the processing device. Brief Description of the Drawings

These and other objects, features, details and/or advantages will become more apparent from the following detailed description of aspects/embodiments of the present invention which is to be taken in conjunction with the appended drawings, in which :

Fig . 1 is an overview showing current UL/DL configurations; Fig . 2 is a diagram illustrating an example of a reporting scheme;

Fig . 3 is a diagram illustrating another example of a reporting scheme;

Fig . 4 is a diagram illustrating an example of a reporting scheme according to certain embodiments of the present invention;

Fig . 5 is a flowchart illustrating an example of a method according to certain embodiments of the present invention; Fig . 6 is a block diagram illustrating an example of an apparatus according to certain embodiments of the present invention;

Fig . 7 is a flowchart illustrating an example of another method according to certain embodiments of the present invention;

Fig . 8 is a block diagram illustrating an example of another apparatus according to certain embodiments of the present invention;

Fig . 9 is a flowchart illustrating different examples for power headroom report according to certain embodiments of the present invention.

Detailed Description In the following, examples and embodiments of the present invention are described with reference to the drawings. For illustrating the present invention, the examples and embodiments will be described in connection with a cellular communication network based on a 3GPP based communication system, for example an LTE/LTE-A based system or a system according to 3G. However, it is to be noted that the present invention is not limited to an application using such types of communication system, but is also applicable to/in other types of communication systems and the like. Basic system architecture of a communication network, where examples of embodiments of the invention are applicable, may comprise a commonly known architecture of one or more communication systems comprising a wired or wireless access network subsystem and a core network. Such an architecture may comprise one or more access network control elements, radio access network elements, access service network gateways, nodes, hosts or servers, which control a coverage area also referred to as a cell and with which one or more communication elements or terminal or user devices such as an UE or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a user device or attached as a separate element to a user device, or the like, are capable to communicate via one or more channels for transmitting several types of data . Furthermore, core network elements such as gateway network elements, policy and charging control network elements, mobility management entities and the like may be comprised . The general functions and interconnections of the described elements, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof is omitted herein. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from a communication element or terminal device, such as a user device and a communication network control element, such as an eNodeB, besides those described in detail herein below. Furthermore, the described network elements, such as an eNB, and the like, as well as corresponding functions as described herein may be implemented by software, e.g . by a computer program product for a computer, and/or by hardware. In any case, for executing their respective functions, correspondingly used devices, nodes or network elements may comprise several means and components (not shown) which are required for control, processing and communication/signaling functionality. Such means may comprise, for example, one or more processor units including one or more processing portions for executing instructions, programs and for processing data, internal and/or external memory means for storing instructions, programs and data, for serving as a work area of the processor or processing portion and the like (e.g . ROM, RAM, EEPROM, and the like), input means for inputting data and instructions by software (e.g . floppy disc, CD-ROM, EEPROM, and the like), user interface means for providing monitor and manipulation possibilities to a user (e.g . a screen, a keyboard and the like), interface means for establishing links and/or connections under the control of the processor unit or portion (e.g. wired and wireless interface means, an antenna, etc.) and the like. It is to be noted that in the present specification processing portions should not be only considered to represent physical portions of one or more processors, but may also be considered as a logical division of the referred processing tasks performed by one or more processors.

According to certain embodiments of the present invention, there is proposed a new method for determining a power headroom report (PHR) for TDD elMTA for at least two subframe sets while still maintaining a possibility for user device -specific PHR triggering and cancelation.

In an example, a user device obtains an UL grant in one subframe (regardless whether this subfame is linked to flexible or fixed UL subframe), and then the user device reports the PH for both subframe sets. A real PH is determined for at least one subframe with UL grant and a virtual PH (similar to virtual PH for carrier aggregation) is determined for at least one subframe set without UL grant.

In this application, a real power headroom means that the headroom is determined for a subframe which is or is to be scheduled, i.e. for which an uplink grant is present (and/or for which the user device really applies a transmission power). A virtual power headroom means that the headroom is determined for a non- scheduled subframe, i.e. a subframe for which no UL grant is present. In this case, typically, scheduling dependent parameters, such as resource block allocation or user device power back-off are not taken into account in the power headroom calculation.

Both kinds of PHs may be reported in one PHR MAC CE (Media Access Control Control Element). In this regard, the extended or enhanced PHR MAC CE defined for carrier aggregation could be reused with two entries (type 1 PHR) for one carrier when it is configured with two subframe sets. Besides, if a simultaneous physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH) transmission is configured for one or all of the subframe sets, type 2 PHR may also be reported for the subframe set (s), where PUCCH can be transmitted, and more than two entries may be reported for one carrier.

In one example, PUSCH can be transmitted in both subframe set 1 and subframe set 2, while PUCCH is only transmitted in subframe set 2 (e.g. which is fixed as UL subframe without dynamic changing transmission direction with UL-DL reconfiguration).

Fig . 4 is a diagram illustrating an example of a reporting scheme according to certain embodiments of the present invention.

In one example, if PHR is triggered (e.g . in subframe 1 as indicated by reference sign 41 shown in Fig . 4) and UL grant is received for subframe (subframe set 1, e.g . subframe 9 as shown in Fig. 4, where the receipt of the UL grant in subframe 5 is indicated by reference sign 42), the power headroom (PH) for subframe set 1 may be determined with real resource allocation (PH typel, PUSCH (physical uplink shared channel) without PUCCH (physical uplink control channel)). Thus, for the subframe set 1 for which an UL grant is received, the real power headroom may be determined and for the subframe set 2, for which no UL grant is received, a virtual power headroom may be determined, as indicated by reference sign 43 in Fig . 4. Then, the power headroom report for both subframes may be conveyed to the eNB, as indicated by reference sign 44 in Fig. 4. It is to be appreciated that in the following exemplifying equations, notations, parameters, symbols etc., are used correspondingly to those of standard TS 36.213. It should be understood, though, that the equations are shown only as clarifying examples which should not be taken as limiting the implementation of embodiments.

If a user device transmits PUSCH without PUCCH in subframe for serving cell c , power headroom for a Type 1 report may be determined as shown below in equation 1 :

Equation 1, real type 1 power headroom (PH) with PUSCH transmission :

U) + a_cj[ (j)^■ PL_C + Δ_Μ ( ) + f_{c k} (i) j

[dB] Where k= l for the subframe set 1.

PH_{typel c k}( denotes for a real power headroom (which is calculated based on real

PUSCH transmission) for subframe /^' of subframe set k for serving cell c according to type 1;

- fcMAx.c O^') ^{is tne} configured maximum user device output power in subframe /^' for serving cell c , as defined in [3GPP TS 36.101] ;

Logio denotes base 10 logarithm; P_{USCH c k}( ) is the bandwidth of the PUSCH resource assignment expressed in number of resource blocks valid for subframe /^' of subframe set k and serving cell c ;

- _o_puscH,c,k 0) ^{is a} parameter composed of the sum of a component

provided from higher layers for j= 0 and 1 and a component

^o_uE_puscH,c,k O) provided by higher layers for j= 0 and 1 for subframe set k of serving cell c . For PUSCH (re)transmissions corresponding to a semi-persistent grant then j= 0, for PUSCH (re)transmissions corresponding to a dynamic scheduled grant then j= 1 and for PUSCH (re)transmissions corresponding to the random access response grant then j= 2. P₀_uE_pusc 0 and

^o_NOMiNAL_puscH ,k (^) ⁼ ^o_PRE + ^PREAMBLE _ where the parameter preamble! nitialReceivedTargetPower [cf. 3GPP TS36.321] ( _{O PRE} ) and _{PREAMBLE Msg3} are signalled from higher layers for serving cell c ; P_{O PRE} is intial preamble power. ^ PREAMBLE _ ^{is a} parameter that impacts the transmit power of PUSCH when responding to random access response grant. - cc_{c k} is a 3-bit parameter provided by higher layers for subframe set k of serving cell c that impacts the calculation of PUSCH transmit power and also scales the

contribution of path loss. For j =0 or 1, cc_{c k} e {o, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, l} . For j = 2,

«_c,t O^') = l ; - PL_C is the downlink pathloss estimate calculated in the user device for serving cell c in dB and PL_c = referenceSignalPower - higher layer filtered RSRP (received signal reference power), where referenceSignalPower is provided by higher layers and RSRP is defined in [3GPP TS 36.214] for the reference serving cell and the higher layer filter configuration is defined in [3GPP TS36.331] for the reference serving cell . If serving cell c belongs to a TAG (Timing Advance Group) containing the primary cell then, for the uplink of the primary cell, the primary cell is used as the reference serving cell for determining referenceSignalPower and higher layer filtered RSRP. For the uplink of the secondary cell, the serving cell configured by the higher layer parameter pathlossReferenceLinking defined in [3GPP TS36.331] is used as the reference serving cell for determining referenceSignalPower and higher layer filtered RSRP. If serving cell c belongs to a TAG not containing the primary cell then serving cell c is used as the reference serving cell for determining referenceSignalPower and higher layer filtered RSRP. - A^^ Ci) = 101og₁₀((2™^JC* - ΐ)- βφ™) for K_S = i.25 and 0 for K_S = o where K_S is given by the parameter deltaMCS- Enabled provided by higher layers for subframe set k of each serving cell c . BPRE and β ^^Η , for each serving cell c , are computed as below. K_S = O for transmission mode 2.

o BPRE = o_CQI /^v_RE for control data sent via PUSCH without U L-SCH (uplink

C-1

shared channel) data and ^ K^N^for other cases.

r=0

where c is the number of code blocks, K_R is the size for code block r , <9_CQI is the number of CQI/PMI (Channel Quality inficator

/ Precoding Matrix Index) bits including CRC (Cyclic Redundancy Check) bits and is the number of resource elements determined asN∞ = M™^S™-^MTIAL - Ν ^-^ . M_s ^p _c ^usch is the scheduled bandwidth for PUSCH transmission in the current sub-frame for the transport block, and

is the number of SC-FDMA symbols per subframe for initial PUSCH transmission for the same transport block.

o β ⁸™ = β for control data sent via PUSCH without UL-SCH data and l for other cases.

- f_c^ (i) reflects the accumulated power control in the same subframe set (subframe set k) until subframe /^' if accumulation is enabled and the latest received TPC command if accumulation is not enabled .

That is to say, according to equation (1), the power headroom may be calculated based on actual uplink resource allocation of the subframe /^' in subframe set 1, using PUSCH power control parameters for subframe set 1 and reflecting an accumulated PUSCH power control for subframe set 1 until or previous to (typically also including) or in the subframe in which the power headroom report in question is conveyed .

PH for subframe set 2 in subframe /^' (e.g . subframe 2 as shown in figure 4), may be calculated as shown in equation 2 correspondingly to that of a virtual PH for carrier aggregation (PH type 1, no PUSCH) :

Equation 2, virtual type 1 PH without PUSCH transmission : pH_typel,_c,_k(i) = p_CMAX,_c(i)- {

} [dB] where k=2 for the subframe set 2. PH_tyvehc (i) denotes a virtual power headroom for subframe / of subframe set k for serving cell c according to type 1;

P_CMAXc( denotes an estimated value of P_CMAXC(i) ;

Here, _CMAX,c ) ^is computed assuming MPR (Maximum Power Reduction) = OdB, A-

MPR (Additional Maximum Power Reduction) = OdB, P-MPR (Power Management Maximum Power Reduction) = OdB and ATc = OdB, where MPR, A-MPR, P-MPR and ATc (ATc is the allowed operating band edge transmission power relaxation) are defined in [3GPP TS 36.101]., and ₀_puscH,_c,k(l) ^ar|d c,k - ^are known to the eNB for subframe set k=2.

- ^o_puscH,c,k(./) ^{is a} parameter composed of the sum of a component ^o_NOMiNAL_puscH,c,kO) provided from higher layers for j=0 and 1 and a component ^o_uE_puscH,c,kO) provided by higher layers for j=0 and 1 for subframe set k of serving cell c . For PUSCH (re)transmissions corresponding to a semi-persistent grant then j=0, for PUSCH (re)transmissions corresponding to a dynamic scheduled grant then j= 1 and for PUSCH (re)transmissions corresponding to the random access response grant then j=2. It is noted that here that in case of virtual PH j in the equation is always 1.

PREAMBLE _Ms_g3 ' where the parameter preamble! nitialReceivedTargetPower [cf. 3GPP TS36.321]; _OPRE and A_{PREAMBLE Msg3} are signalled from higher layers for serving cell c; P_{Q PRE} is intial preamble power; ^ PREAMBLE _ Msg 3 '^{s 3} parameter that impacts the transmit power of PUSCH when responding to random access response grant, and ^_o_NOMiNAL_puscH,c,k0) ^{is a} parameter that impacts the calculation of PUSCH transmit power. - _{c k} is a 3-bit parameter provided by higher layers for subframe set k of serving cell c that impacts the calculation of PUSCH transmit power and also scales the

contribution of path loss. For j =0 or 1, a_{c k} e {o, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, l} . For j = 2, «_,*(./) = i ;

- PL_C is the downlink pathloss estimate calculated in the user device for serving cell c in dB and PL_c = referenceSignalPower - higher layer filtered RSRP (received signal reference power), where referenceSignalPower is provided by higher layers and RSRP is defined in [3GPP TS 36.214] for the reference serving cell and the higher layer filter configuration is defined in [3GPP TS36.331] for the reference serving cell . If serving cell c belongs to a TAG (Timing Advance Group) containing the primary cell then, for the uplink of the primary cell, the primary cell is used as the reference serving cell for determining referenceSignalPower and higher layer filtered RSRP. For the uplink of the secondary cell, the serving cell configured by the higher layer parameter pathlossReferenceLinking defined in [3GPP TS36.331] is used as the reference serving cell for determining referenceSignalPower and higher layer filtered RSRP. If serving cell c belongs to a TAG not containing the primary cell then serving cell c is used as the reference serving cell for determining referenceSignalPower and higher layer filtered RSRP.

- f_c {i) reflects the accumulated power control in the other subframe set than the subframe set of subframe i (subframe set 2) until subframe /^'. That is to say, according to equation (2), a power headroom may be calculated based on preconfigured PUSCH power control parameters for subframe set 2 and a close loop power control result for PUSCH for the subframe set 2 until or previous to (typically also including) or in subframe /^'. If simultaneous PUSCH and PUCCH transmission is configured for a serving cell with PUCCH, type 2 PHR may be reported for subframe set 2 using the following PH formula (PH type 2, without PUSCH and PUCCH) as shown in equation 3 : Equation 3, virtual type 2 PH without PUSCH nor PUCCH transmission:

Where k=2 for the subframe set 2

PH_type2ck( denotes a virtual power headroom for subframe / of subframe set 2 for serving cell c according to type 2;

-

o_puscH,_c,k(l)/ «_c,* CD ^and Λ* (0 ^{a re as} defined above for subframe set k, and where g_ck(i) is the current PUCCH power control

adjustment state for subframe set k and where

the first value after reset. For TDD, values of M and k_m are given in the following (Table 10.1.3.1-1 of reference [3]). TPC command (<¾_>UCCH_Ck) ^is accumulated within the downlink association set.

Downlink association set index K : {^,^,···^^} for TDD

- ₀_puccH_,c,k ^{is a} parameter composed of the sum of a parameter ₀__NOMINAL__PUCCH,C,I provided by higher layers and a parameter P_Q __UE __PUCCHiCik provided by higher layers fo the serving cell c and the subframe set k; - <¾,_{UCCH c k} is a user device specific correction value, also referred to as a TPC command, included in a PDCCH (Physical Downlink Control Channel) with DCI format 1A/1 B/1 D/1/2A/2/2B/2C/2D for a serving cell c with PUCCH, or included in an EPDCCH (Enhanced Physical Downlink Control Channel) with DCI (downlink control information) format 1A/1 B/1 D/1/2A/2/2B/2C/2D for a serving cell c with PUCCH, or sent jointly coded with other user device -specific PUCCH correction values on a PDCCH with DCI format 3/3A whose CRC parity bits are scrambled with TPC-PUCCH- RNTI (Transmit Power Control - Physical Uplink Control Channel - Radio Network Temporary Identifier) .

That ist o say, according to equation (3), the power headroom may be calculated based on preconfigured power control parameters for PUSCH and PUCCH for subframe set 2 and close loop power control result for PUSCH and PUCCH for the subframe set 2 until or previous to (typically including) or in subframe /^'.

Correspondingly, if U L grant is received at a subframe of subframe set 2, real type 1 PHR for subframe 2 may be reported for subframe set 2 (see equation 1 if no PUCCH transmission at the same subframe with k= 2 and see equation 4 if there is PUCCH transmission at the same subframe). If serving cell c is configured with PUCCH, real type 2 PH R (see equation 5) or real type 2 PHR (see equation 6) for subframe set 2 may be reported depending on whether there is PUCCH transmission at the same time. Additionally, virtual type 1 PH R for subframe set 1 may be reported (see equation 2, replace the power control parameters and power control accumulation with the ones for subframe set 1, i.e. k= l .).

Equation 4, real type 1 PH with both PUSCH and PUCCH transmission :

U) + a_cjc (J)^■ PL_C + A_{TF Cik} ( ) + f_{c ]i} (i) )

[dB]

Where k=2 for subframe set 2.

^CMAX _c( ^is computed based on the requirements in 3GPP TS36.101 assuming a

PUSCH only transmission in subframe /^'. PcMAX ( ^PUSCH.c.k ' ^0_PUSCH,c,k a A and /_Cjt(i) are as defined above for subframe set k=2;

That is to say, according to equation (4), the power headroom may be calculated based on actual uplink resource allocation of the subframe /^'assuming no PUCCH transmission by using PUSCH power control parameters for subframe set 2 is carried out, an information reflecting PUSCH power control for subframe set 2 until or previous to (typically inlcuding) or in the subframe in which a power headroom report is conveyed.

Equation 5, real type 2 PH with both PUSCH and PUCCH transmission:

Where k=2 for subframe set 2.

- PH_type2c ' ^CMAXfi^) .c.k .c.k

/_{c A}( )and g_ckd)are as defined above for subframe set k=2;

- o_puccH,c,k is a parameter composed of the sum of a parameter ^

provided by higher layers and a parameter P_Q __UE __PUCCHiCik provided by higher layers for the serving cell c and subframe set k. (If only one serving cell can be configured with PUCCH, the subscript for serving cell "c" could be omitted. If only one subframe set can be configured with PUCCH, the subscript for subframe set "k" could be omitted.) • - h[ⁿCQI 'ⁿHARQ'ⁿSR J is a PUCCH format dependent value, where n_CQI corresponds to the number of information bits for the channel quality information defined in section 5.2.3.3 in [4]. n_SR = 1 if subframe /^' is configured for SR for the user device not having any associated transport block for UL-SCH, otherwise n_SR =0.

If the user device is configured with more than one serving cell, or the user device is configured with one serving cell and transmitting using PUCCH format 3, the value of n_HARQ is determined based on UL-DL configuration and HARQ-

ACK feedback on PUCCH format 3 or lb with channel selection; otherwise, n_HARQ is the number of HARQ-ACK bits sent in subframe /^'. For PUCCH format 1,1a and lb

For PUCCH format lb with channel selection, if the user device is configured with more than one serving cell, h(n_CQI , n_HARQ, n_SR ) = ^^HARQ— ^ll _t

Otherwise, h(n_CQI,n_HARQ,n_SR)=0

For PUCCH format 2, 2a, 2b and normal cyclic prefix nCQI

101og₁₀ if n_CQI > 4

h(n_CQI,n_HARQ n_SR

0 otherwise

o For PUCCH format 2 and extended cyclic prefix

r ⁿCQI + ⁿHARQ

101og₁₀ if n.

h(n_CQI ,n_HARQ n_SR CQI^{† n}HARQ >4

0 otherwise

For PUCCH format 3 and when user device transmits HARQ-ACK/SR without periodic CSI,

^■ If the user device is configured by higher layers to transmit PUCCH format 3 on two antenna ports, or if the user device transmits more than 11 bits of HARQ-ACK/SR nHARQ +ⁿSR ^{~ l}

h(ⁿCQI ' ⁿHARQ ' ⁿSR ) ^:

3

Otherwise

nHARQ + ⁿSR

h(n_CQI ,n_HARQ,n_SR) o For PUCCH format 3 and when user device transmits HARQ-ACK/SR and periodic CSI,

^■ If the user device is configured by higher layers to transmit PUCCH format 3 on two antenna ports, or if the user device transmits more than 11 bits of HARQ-ACK/SR and CSI

HARQ ^τ ' SR ^τ "'CQI

h(ⁿCQI ' ⁿHARQ

Otherwise

"HARQ ^τ ' SR ^τ ' CQ1

h(ⁿCQI ' ⁿHARQ - A_{F PUCCH}( ) is compensation of different PUCCH format compared with format la in power control,. Each A_{F PUCCH}( ) value corresponds to a PUCCH format (F) relative to PUCCH format la, where each PUCCH format (F) is defined in below

Supported PUCCH formats.

- ^T_XD ^^F' ^ is for transmission power compensation in case the user device is configured by higher layers to transmit PUCCH on two antenna ports, the value of A_TxD(F')\s provided by higher layers where each PUCCH format F is defined in above table; otherwise, A_TxD(F') = 0

That is to say, according to equation (5), a power headroom may be calculated based on actual uplink resource allocation for PUSCH and PUCCH transmission of the subframe /^' in subframe set 2 by using PUSCH and PUCCH power control parameters for subframe set 2, and information reflecting PUSCH and PUCCH power control for subframe set 2 until or previous to (typically inlcuding) or in the subframe when power headroom report is conveyed.

Equation 6, real type 2 PH with PUSCH and without PUCCH transmission:

Where k=2 for subframe set 2. PH_tyve2cX(i) , P_CMAX i) , _PUSCHck() , P_o_pusc _,k0^') , ^ack(j)> ^FLci

^ANCL « ^{3 re 3S} defined above for subframe set k=2; That is, according to equation (6), the real power headroom is calculated based on actual uplink resource allocation for PUSCH of the subframe i in subframe set 2 by using PUSCH and PUCCH power control parameters for subframe set 2, and a function reflecting PUSCH and PUCCH power control for subframe set 2 until the subframe when power headroom report is conveyed.

In another example if both PUSCH and PUCCH may be transmitted in both subframe

set 1 and subframe set 2, real or virtual type 1 and type 2 PHR may depend on

whether there is PUSCH/PUCCH transmission the subframe when PHR is reported

according to exemplifying equations below.

• If PHR is triggered (e.g . subframe 1 as shown in figure 4) and UL grant is

received for subframe (subframe set 1, e.g . subframe 9 as shown in figure

4),

o the power headroom (PH) for subframe set 1 is calculated

■ serving cell c, UE transmits PUSCH without PUCCH in subframe /^',

real type 1 PHR is calculated as equation 1

^ CMAX.c (0- ( 10 log₁₀(M_{PUSCH c} (ί)) + ^ 0_PUSCH,c,l (^j) + (j) + ^ATF,c, l( + .

[dB] ■ serving cell c, user device transmits PUSCH with PUCCH in

subframe /^', real type 1 PHR is calculated as modified equation 4

(subframe set 1)

^ CMAX.c ^0_PUSCH,c,l

[dB]

■ serving cell c, user device transmits PUSCH with PUCCH in

subframe /^', real type 2 PHR is calculated as modified equation 5

(subframe set 1)

[dB]

serving cell c, user device transmits PUSCH without PUCCH in

subframe /^', real type 2 PHR is calculated as modify equation 6

(subframe set 1)

[dB] the power headroom (PH) for subframe set 2 is calculated

^■ for serving cell c, virtual type 1 PH without PUSCH transmission, calculated as below equation 2

PH_typel,_c, ₂(i) = PcMAxAi)- " ^ + /c,₂ ⁽0 }

[dB]

^■ serving cell c, virtual type 2 PH without PUSCH nor PUCCH

transmission is calculated as equation 3

[dB]

• If UL grant is received for subframe in subframe set 2, above principle may also be applied with subframe set exchange in equations.

The parameters in equations above have the meaning as defined in relation to another example.

The PH for two subframe sets may be included in one PHR MAC CE reusing the current format by including multiple PHs for one serving cell with pre-defined order, if the serving cell is configured with two subframe sets which are known to the eNB based on configuration, e.g. in the order of type 1 PH for subframe set 1, type 2 PH for subframe set 1, type 1 PH for subframe set 2 and type 2 PH for subframe set 2. Type 2 PH is only included if PUCCH is configured for the subframe set of the serving cell.

Thus, it is possible to keep per user device PHR trigger/cancellation and reuse carrier aggregation (CA) concept with least change to report PHR for two subframe sets.

Fig . 9 is a flowchart illustrating different simplified examples for power headroom report according to certain embodiments of the present invention. In the examples, it is assumed that 2 subframe sets are configured and a subframe comprising a PHR is in subframe set 1 of these two subframe sets. The number of subframe sets is two for the sake of clarity and it should not be taken as a limitation. In the examples, UL resources are granted for a transmission at a subframe including the determined power headroom report (PHR) (S91).

If no simultaneous PUSCH and PUCCH transmission is configured, PH in the PHR comprises: real type 1 PH for subframe set (SS) 1 (according to Equation 1 (El)) and virtual type 1 PH for SS2 (according to Equation 2 (E2)) (S92-S94).

If a simultaneous PUSCH and PUCCH transmission is configured for subframe set 2 and not configured for subframe set 1, PH in the PHR comprises: real type 1 PH for subframe set (SS) 1 (according to Equation 1 (El)), virtual type 1 PH for SS2 (according to Equation 2 (E2)) and virtual type 2 PH for SS2 (according to Equation 3 (E3)) (S92-S95).

If a simultaneous PUSCH and PUCCH transmission is configured for subframe set 1 and not configured for subframe set 2, and there is no PUCCH transmission at the subframe in which PHR is transmitted, PH in the PHR comprises: real type 1 PH for subframe set (SS) 1 (according to Equation 1 (El)), virtual type 2 PH for SSI (according to Equation 6 (E6)) and virtual type 1 PH for SS2 (according to Equation 2 (E2)) (S92, S96-S98).

If a simultaneous PUSCH and PUCCH transmission is configured for subframe set 1 and there is no PUCCH transmission at the subframe in which PHR is transmitted, and a simultaneous PUSCH and PUCCH transmission is configured for subframe set 2, PH in the PHR comprises: real type 1 PH for subframe set (SS) 1 (according to Equation

1 (El)), virtual type 2 PH for SSI (according to Equation 6(E6)), virtual type 1 PH for SS2 (according to Equation (E2)) and virtual type 2 PH for SS2 (according to

Equation 3 (E3)) (S92, S96-S99).

If a simultaneous PUSCH and PUCCH transmission is configured for subframe set 1 and not configured for subframe set 2, and there is PUCCH transmitted at the subframe when PHR is reported, PH in the PHR comprises: real type 1 PH for subframe set (SS) 1 (according to Equation 4 (E4)), real type 2 PH for SSI (according to Equation 5 (E5)), and virtual type 1 PH for SS2 (according to Equation

2 (E2)) (S92, S96, S910, S911).

If a simultaneous PUSCH and PUCCH transmission is configured for subframe set 1 and for subframe set 2, and PUCCH is transmitted at the subframe when PHR is reported , PH in the PHR comprises: real type 1 PH for subframe set (SS) 1 (according to Equation 4 (E4)), real type 2 PH for SSI (according to Equation 5 (E5)), virtual type 1 PH for SS2 (according to Equation 2 (E2)) and virtual type 2 PH for SS2 (according to Equation 3 (E3)) (S92, S96, S910, S912).

Fig . 5 is a flowchart illustrating an example of a method according to certain embodiments of the present invention.

According to certain embodiments of the present invention, the method may be implemented in a user device or user equipment or a part of it and the exemplifying method comprises obtaining, at a user device, configuration information for at least two subframe sets for a serving cell in a step S51, and determining for a power headroom report, at the user device, at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed and the virtual power headroom being for at least one another subframe set in a step S52.

According to certain aspects of the present invention, the determining of the real power headroom is based on an actual uplink resource allocation and the virtual power headroom is based on an estimate determined without uplink resource allocation.

According to certain aspects of the present invention, the at least a first subframe set and a second subframe set and corresponding power control parameters for each subframe set are configured by network.

According to certain aspects of the present invention, the first subframe set and the second subframe set contains the subframes configured by networks (e.g. subframe 2 for subframe set 1 and subframe 3, 4, 8, 9 for subframe set 2).

According to certain aspects of the present invention, the method further comprises composing a control element for media access control in one subframe or in one physical data unit, PDU, comprising the real power headroom and the virtual power headroom in such an order that the real power headroom is previous to the virtual power headroom.

According to certain aspects of the present invention, the method further comprises composing a control element for media access control in one subframe or in one physical data unit, PDU, the power headroom is included in such a order that the power headroom for a first subframe set as configured by the network is previous to the power headroom for a second subframe set as configured by the network. According to certain aspects of the present invention, the virtual power headroom is determined based on power control parameters obtained from a network control element for the at least one another subframe set, reflecting estimated pathloss as well as closed loop power control result for at least one subframe set previous to the subframe in which the power headroom report is conveyed .

According to certain aspects of the present invention, the real power headroom is determined based on actual uplink resource allocation and power control parameters for the subframe set of the subframe, in which the power headroom report is conveyed, reflecting estimated pathloss as well as closed loop power control result for at least one subframe set in the subframe in which the power headroom report is conveyed.

According to certain aspects of the present invention, if simultaneous transmission of physical uplink shared channel and physical uplink control channel is not configured for the subframe set of the subframe, in which the power headroom report is conveyed, the real power headroom is determined according to actual uplink resource allocation of the subframe in which the power headroom report is conveyed by using at least one of the following : an upper limit for user device output power, a bandwidth of the physical uplink shared channel resource assignment expressed in number of resource blocks, a parameter used to control a signal level target value at a node, a pathloss estimate, a pathloss compensation factor, a modulation and coding scheme dependent scaling factor, and a function reflecting closed loop power control result for the corresponding subframe set in the subframe in which the power headroom report is conveyed. According to certain aspects of the present invention, the real power headroom for one subframe set with uplink grant at the subframe when power headroom is reported is determined by using :

^CMAX 0^') + a_CJCU)^■ PL_C + A_{TF Cik} ( ) + f_cjc (i) )

[dB] . Where k= l for a first subframe set and k= 2 for a second subframe set.

According to certain aspects of the present invention, the virtual power headroom is determined by using at least one of the following : an upper limit for user device output power, a power control parameter for the physical uplink shared channel, a pathloss estimate, and a function reflecting closed loop power control result of the corresponding subframe set in the subframe in which the power headroom report is conveyed . According to certain aspects of the present invention, the virtual power headroom for the subframe set without uplink grant at the subframe when power headroom is reported is determined by using :

PH_tyM(i) = P_CMAXJi)- {

+ «_c,,a) - ¾_c + _c,, ( } [d B],

where k= l for subframe set 1 and k= 2 for subframe set 2. f_{c k}(i) is accumulated power control for the corresponding subframe set (other than the subframe set when the power headroom is conveyed) until the subframe when power headroom report is conveyed .

According to certain aspects of the present invention, if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the at least one another subframe set, the virtual power headroom is determined by using at least one of the following : an upper limit for user device output power, power control parameters for physical uplink shared channel and physical uplink control channel, a pathloss estimate, and functions reflecting closed loop power control result.

According to certain aspects of the present invention, the virtual type 2 power headroom for the subframe set without uplink grant at the subframe when power headroom is reported is determined by using :

Where k= l for subframe set 1 and k=2 for subframe set 2. _{c t} ( and _{gc k} d) are accumulated power control for the corresponding subframe set for physical uplink shared channel and physical uplink control channel until the subframe when power headroom is conveyed.

According to certain aspects of the present invention, if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the subframe set of the subframe, in which the power headroom report is conveyed, and there is physical uplink control channel transmission at the subframe in which the power headroom report is conveyed, the real power headroom is determined based on at least one of: actual uplink resource allocation of the subframe, in which the power headroom report is conveyed assuming no physical uplink control channel transmission by using physical uplink shared channel power control parameters for the corresponding subframe set, a bandwidth of the physical uplink shared channel resource assignment expressed in number of resource blocks, and a function reflecting closed loop physical uplink shared channel power control result for the corresponding subframe set in the subframe in which power headroom report is conveyed.

According to certain aspects of the present invention, if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the subframe set of the subframe, in which the power headroom report is conveyed, and there is physical uplink control channel transmission at the subframe in which the power headroom report is conveyed, the real power headroom is determined based on at least one of: actual uplink resource allocation for physical uplink shared channel and physical uplink control channel transmission of the subframe, in which the power headroom report is conveyed, by using physical uplink shared channel and physical uplink control channel power control parameters for the corresponding subframe set, a bandwidth of the physical uplink shared channel resource assignment expressed in number of resource blocks and a function reflecting closed loop physical uplink shared channel and physical uplink control channel power control result for the corresponding subframe set in the subframe, in which the power headroom report is conveyed. According to certain aspects of the present invention, if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the subframe set of the subframe, in which the power headroom report is conveyed, and there is no physical uplink control channel transmission at the subframe in which the power headroom report is conveyed, the real power headroom is determined based on at least one of the following : actual uplink resource allocation for physical uplink shared channel of a subframe in the subframe, in which the power headroom report is conveyed by using at least one of the following : physical uplink shared channel and physical uplink control channel power control parameters for the corresponding subframe set, and a function reflecting closed loop physical uplink shared channel and physical uplink control channel power control result for the corresponding subframe set in the subframe, in which the power headroom report is conveyed.

According to certain aspects of the present invention, the user device is operated in a time division duplex system applying uplink-downlink interference management and traffic adaptation.

Fig . 6 is a block diagram showing an example of an apparatus according to certain embodiments of the present invention. In Fig . 6, a block circuit diagram illustrating a configuration of an apparatus 60, such as of a user device or part of a user device, is shown, which is configured to implement the above described aspects of the invention. It is to be noted that the apparatus 60 shown in Fig. 6 may comprise several further elements or functions besides those described herein below, which are omitted herein for the sake of simplicity as they are not essential for understanding the invention. Furthermore, even though reference is made to a user device, the apparatus may be also another device having a similar function, such as a chipset, a chip, a module etc., which can also be part of a user device or attached as a separate element to a user device, or the like.

The apparatus 60 may comprise a processing function or processor 61, such as a CPU or the like, which executes instructions given by programs or the like. The processor

61 may comprise one or more processing portions dedicated to specific processing as described below, or the processing may be run in a single processor. Portions for executing such specific processing may be also provided as discrete elements or within one or more (additional) processors or processing portions, such as in one physical processor, such as a CPU or in several physical entities, for example. Reference sign 62 denotes an optional transceiver or input/output (I/O) units (interfaces) connected to the processor 61. The I/O units 62 may be used for communicating with one or more management entities and/or nodes. The I/O units

62 may be a combined unit comprising communication equipment towards several network elements, or may comprise a distributed structure with a plurality of different interfaces for different network elements. Reference sign 63 denotes a memory usable, for example, for storing data and programs to be executed by the processor 61 and/or as a working storage of the processor 61. The processor 61 is configured to execute processing related to the above described aspects. In particular, the processor 61 is configured to perform obtaining, at a user device, configuration information for at least two subframe sets for a serving cell, and determining for a power headroom report at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed and the virtual power headroom being for at least one another subframe set.

For further functions of the apparatus according to further example embodiments of the present invention, reference is made to the above description of methods according to certain embodiments of the present invention, as described in connection with Fig. 5.

According to certain aspects of the present invention, there is also provided a user device that comprises any apparatus as defined above. Fig . 7 is a flowchart illustrating another example of a method according to certain embodiments of the present invention. According to certain embodiments of the present invention, the method may be implemented in a node, such as an eNodeB or part of it and the exemplifying method comprises carrying out configuration of resources for at least two subframe sets for a serving cell in a step S71, obtaining, at a node, a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained and the virtual power headroom being for at least one another subframe seta step S72, and performing scheduling for the subframe sets based on the power headroom report in a step S73.

Fig . 8 is a block diagram showing an example of another apparatus according to certain embodiments of the present invention. In Fig . 8, a block circuit diagram illustrating a configuration of an apparatus 80, such as of a node, server or host or a part of it, is shown, which is configured to implement the above described aspects of the invention. It is to be noted that the apparatus 80 shown in Fig. 8 may comprise several further elements or functions besides those described herein below, which are omitted herein for the sake of simplicity as they are not essential for understanding the invention. Furthermore, even though reference is made to a user device, the apparatus may be also another device having a similar function, such as a chipset, a chip, a module etc., which can also be part of a or attached as a separate element to a node, server or host, or the like.

The apparatus 80 may comprise a processing function or processor 81, such as a CPU or the like, which executes instructions given by programs or the like. The processor 81 may comprise one or more processing portions dedicated to specific processing as described below, or the processing may be run in a single processor. Portions for executing such specific processing may be also provided as discrete elements or within one or more (additional) processors or processing portions, such as in one physical processor, such as a CPU or in several physical entities, for example. Reference sign 82 denotes an optional transceiver or input/output (I/O) units, modules or interfaces connected to the processor 81. The I/O units 82 may be used for communicating with one or more management entities and/or user equipments. The I/O units 82 may be a combined unit comprising communication equipment towards several network elements, or may comprise a distributed structure with a plurality of different interfaces for different network elements. Reference sign 83 denotes a memory usable, for example, for storing data and programs to be executed by the processor 81 and/or as a working storage of the processor 81.

The processor 81 is configured to execute processing related to the above described aspects. In particular, the processor 81 is configured to perform carrying out configuration of resources for at least two subframe sets for a serving cell, obtaining, at a node, a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained and the virtual power headroom being for at least one another subframe set, performing scheduling for the subframe sets based on the power headroom report.

According to certain aspects of the present invention, there is also provided a node, server or host that comprises the apparatus as defined above.

In the foregoing exemplary description of the apparatuses, only the units/means that are relevant for understanding the principles of the invention have been described using functional blocks. The apparatus may comprise further units/means that are necessary for its respective operation as user device or node, server or host. However, a description of these units/means is omitted in this specification. The arrangement of the functional blocks of the apparatus is not construed to limit the invention, and the functions may be performed by one block or further split into sub- blocks. When in the foregoing description it is stated that the apparatus (or some other means) is configured to perform some function, this is to be construed to be equivalent to a description stating that a (i.e. at least one) processor or corresponding circuitry, potentially in cooperation with computer program code stored in the memory of the respective apparatus, is configured to cause the apparatus to perform at least the thus mentioned function. Also, such function is to be construed to be equivalently implementable by specifically configured circuitry or means for performing the respective function (i.e. the expression "unit configured to" is construed to be equivalent to an expression such as "means for").

For the purpose of the present invention as described herein above, it should be noted that

- method steps likely to be implemented as software code portions and being run using a processor at an apparatus (as examples of devices, apparatuses and/or modules thereof, or as examples of entities including apparatuses and/or modules therefore), are software code independent and can be specified using any known or future developed programming language as long as the functionality defined by the method steps is preserved;

- generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the aspects/embodiments and its modification in terms of the functionality implemented;

- method steps and/or devices, units or means likely to be implemented as hardware components at the above-defined apparatuses, or any module(s) thereof, (e.g ., devices carrying out the functions of the apparatuses according to the aspects/embodiments as described above) are hardware independent and can be implemented using any known or future developed hardware technology or any hybrids of these, such as MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), TTL (Transistor-Transistor Logic), etc., using for example ASIC (Application Specific IC (Integrated Circuit)) components, FPGA (Field-programmable Gate Arrays) components, CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components;

- devices, units or means (e.g . the above-defined apparatuses, or any one of their respective units/means) can be implemented as individual devices, units or means, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device, unit or means is preserved;

- an apparatus may be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of an apparatus or module, instead of being hardware implemented, be implemented as software in a (software) module such as a computer program or a computer program product comprising executable software code portions for execution/being run on a processor;

- a device may be regarded as an apparatus or as an assembly of more than one apparatus, whether functionally in cooperation with each other or functionally independently of each other but in a same device housing, for example.

In general, it is to be noted that respective functional blocks or elements according to above-described aspects can be implemented by any known means, either in hardware and/or software, respectively, if it is only adapted to perform the described functions of the respective parts. The mentioned method steps can be realized in individual functional blocks or by individual devices, or one or more of the method steps can be realized in a single functional block or by a single device.

Generally, any method step is suitable to be implemented as software or by hardware without changing the idea of the present invention. Devices and means can be implemented as individual devices, but this does not exclude that they are implemented in a distributed fashion throughout the system, as long as the functionality of the device is preserved. Such and similar principles are to be considered as known to a skilled person.

Software in the sense of the present description comprises software code as such comprising code means or portions or a computer program or a computer program product for performing the respective functions, as well as software (or a computer program or a computer program product) embodied on a tangible medium such as a computer-readable (storage) medium having stored thereon a respective data structure or code means/portions or embodied in a signal or in a chip, potentially during processing thereof. It is noted that the aspects/embodiments and general and specific examples described above are provided for illustrative purposes only and are in no way intended that the present invention is restricted thereto. Rather, it is the intention that all variations and modifications which fall within the scope of the appended claims are covered.

Claims

W HAT I S CLA I M ED I S:

1. A method, comprising :

obtaining, at a user device, configuration information for at least two subframe sets for a serving cell, and

determining for a power headroom report, at the user device, at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed, and the virtual power headroom being for at least one another subframe set.

2. The method according to claim 1, wherein

the determining of the real power headroom is based on an actual uplink resource allocation and the virtual power headroom is based on an estimate determined without uplink resource allocation.

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

composing a control element for media access control in one subframe or in one physical data unit, PDU, comprising the real power headroom and the virtual power headroom in such an order that the real power headroom is previous to the virtual power headroom.

4. The method according to any one of claims 1 to 3, further comprising :

composing a control element for media access control in one subframe or in one physical data unit, PDU, the power headroom is included in such a order that the power headroom for a first subframe set as configured by the network is previous to the power headroom for a second subframe set as configured by the network.

5. The method according to any one of claims 1 to 4, wherein

the virtual power headroom is determined based on power control parameters obtained from a network control element for the at least one another subframe set, reflecting estimated pathloss as well as closed loop power control result for at least one subframe set previous to the subframe in which the power headroom report is conveyed.

6. The method according to any one of claims 1 to 5, wherein

the real power headroom is determined based on actual uplink resource allocation and power control parameters for the subframe set of the subframe, in which the power headroom report is conveyed, reflecting estimated pathloss as well as closed loop power control result for at least one subframe set in the subframe in which the power headroom report is conveyed .

7. The method according to any one of claims 1 to 6, wherein

if simultaneous transmission of physical uplink shared channel and physical uplink control channel is not configured for the subframe set of the subframe, in which the power headroom report is conveyed, the real power headroom is determined according to actual uplink resource allocation of the subframe in which the power headroom report is conveyed by using at least one of the following : an upper limit for user device output power, a bandwidth of the physical uplink shared channel resource assignment expressed in number of resource blocks, a parameter used to control a signal level target value at a node, a pathloss estimate, a pathloss compensation factor, a modulation and coding scheme dependent scaling factor, and a function reflecting closed loop power control result for the corresponding subframe set in the subframe in which the power headroom report is conveyed.

8. The method according to any one of claims 1 to 7, wherein

the real power headroom for one subframe set with uplink grant at the subframe when power headroom is reported is determined by using :

^CMAX.c (0- ( 101og₁₀( _PUSCHiCik( ) + ^0_PUSCH,c,k

[dB] .

9. The method according to any one of claims 1 to 8, wherein

the virtual power headroom is determined by using at least one of the following : an upper limit for user device output power, a power control parameter for the physical uplink shared channel, a pathloss estimate, and a function reflecting closed loop power control result of the corresponding subframe set in the subframe in which the power headroom report is conveyed .

10. The method according to any one of claims 1 to 9, wherein

the virtual power headroom is determined by using :

1 [dB] .

11. The method according to any one of claims 1 to 10, wherein,

if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the at least one another subframe set, the virtual power headroom is determined by using at least one of the following : an upper limit for user device output power, power control parameters for physical uplink shared channel and physical uplink control channel, a pathloss estimate, and functions reflecting closed loop power control result.

12. The method according to any one of claims 1 to 11, wherein

if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the at least one another subframe set, the virtual power headroom is determined by using :

which and _{gc k} d) are accumulated power control for the subframe set for physical uplink shared channel and physical uplink control channel previous to the subframe in which power headroom is conveyed.

13. The method according to any one of claims 1 to 12, wherein

if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the subframe set of the subframe, in which the power headroom report is conveyed, and there is physical uplink control channel transmission at the subframe in which the power headroom report is conveyed, the real power headroom is determined based on at least one of: actual uplink resource allocation of the subframe, in which the power headroom report is conveyed assuming no physical uplink control channel transmission by using physical uplink shared channel power control parameters for the corresponding subframe set, a bandwidth of the physical uplink shared channel resource assignment expressed in number of resource blocks, and a function reflecting closed loop physical uplink shared channel power control result for the corresponding subframe set in the subframe in which power headroom report is conveyed.

14. The method according to any one of claims 1 to 13, wherein

if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the subframe set of the subframe, in which the power headroom report is conveyed, and there is physical uplink control channel transmission at the subframe in which the power headroom report is conveyed, the real power headroom is determined based on at least one of: actual uplink resource allocation for physical uplink shared channel and physical uplink control channel transmission of the subframe, in which the power headroom report is conveyed, by using physical uplink shared channel and physical uplink control channel power control parameters for the corresponding subframe set, a bandwidth of the physical uplink shared channel resource assignment expressed in number of resource blocks and a function reflecting closed loop physical uplink shared channel and physical uplink control channel power control result for the corresponding subframe set in the subframe, in which the power headroom report is conveyed.

15. The method according to any one of claims 1 to 14, wherein

if simultaneous transmission of physical uplink shared channel and physical uplink control channel is configured for the subframe set of the subframe, in which the power headroom report is conveyed, and there is no physical uplink control channel transmission at the subframe in which the power headroom report is conveyed, the real power headroom is determined based on at least one of the following : actual uplink resource allocation for physical uplink shared channel of a subframe in the subframe, in which the power headroom report is conveyed by using at least one of the following : physical uplink shared channel and physical uplink control channel power control parameters for the corresponding subframe set, and a function reflecting closed loop physical uplink shared channel and physical uplink control channel power control result for the corresponding subframe set in the subframe, in which the power headroom report is conveyed.

16. The method according to any one of claims 1 to 15, wherein

the user device is operated in a time division duplex system applying uplink- downlink interference management and traffic adaptation.

17. A method, comprising :

carrying out configuration of resources for at least two subframe sets for a serving cell,

obtaining, at a node, a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained, and the virtual power headroom being for at least one another subframe set,

performing scheduling for the subframe sets based on the power headroom report.

18. The method according to claim 17, wherein the node is operated in a time division duplex system applying uplink-downlink interference management and traffic adaptation .

19. The method according to claim 17 or 18, wherein the configuration further comprises determining of power control parameters.

20. The method according to any one of claims 17 to 19, further comprising :

in case of carrier aggregation, carrying out configuration for at least two subframe sets for a serving cell of each of the used carriers.

21. An apparatus, comprising :

at least one processor, and

at least one memory for storing instructions to be executed by the processor, wherein

the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus at least to perform : obtaining configuration information for at least two subframe sets for a serving cell, and

determining for a power headroom report at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed, and the virtual power headroom being for at least one another subframe set.

22. The apparatus according to claim 21, wherein

23. The apparatus according to any one of claims 21 to 22, wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the apparatus to perform :

24. The apparatus according to any one of claims 21 to 23, wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the apparatus to perform :

25. The apparatus according to any one of claims 21 to 24, wherein

26. The apparatus according to any one of claims 21 to 25, wherein

27. The apparatus according to any one of claims 21 to 26, wherein

28. The apparatus according to any one of claims 21 to 27, wherein

^CMAX.c (0- ( 101og₁₀( _PUSCHiCik( ) + ^0_PUSCH,c,k

[dB] .

29. The apparatus according to any one of claims 21 to 28, wherein

30. The apparatus according to any one of claims 21 to 29, wherein

the virtual power headroom is determined by using :

(0- ^0_PUSCH, c,k + a_Ctk - PL_c + f_Ctk(i) } [dB] .

31. The apparatus according to any one of claims 21 to 30, wherein,

32. The apparatus according to any one of claims 21 to 31, wherein

33. The apparatus according to any one of claims 21 to 32, wherein

34. The apparatus according to any one of claims 21 to 33, wherein

35. The apparatus according to any one of claims 21 to 34, wherein

36. The apparatus according to any one of claims 21 to 35, wherein

37. An apparatus, comprising :

at least one processor, and

the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus at least to perform :

obtaining a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained, and the virtual power headroom being for at least one another subframe set,

performing scheduling for the subframe sets based on the power headroom report.

38. The apparatus according to claim 37, wherein the node is operated in a time division duplex system applying uplink-downlink interference management and traffic adaptation .

39. The apparatus according to claim 37 or 38, wherein the configuration further comprises determining of power control parameters.

40. The apparatus according to any one of claims 37 to 39, wherein the at least one memory and the instructions are further configured to, with the at least one processor, cause the apparatus to perform : in case of carrier aggregation, carrying out configuration for at least two subframe sets for a serving cell of each of the used carriers.

41. An apparatus, comprising :

means for obtaining configuration information for at least two subframe sets for a serving cell, and

means for determining for a power headroom report at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration information is obtained, the real power headroom being for a subframe set of the subframe, in which the power headroom report is conveyed and the virtual power headroom being for at least one another subframe set.

42. An apparatus, comprising :

means for carrying out configuration of resources for at least two subframe sets for a serving cell,

means for obtaining a power headroom report for the at least two subframe sets, the power headroom report comprising at least one real power headroom and at least one virtual power headroom for the at least two subframe sets for which the configuration is carried out, the real power headroom being for a subframe set of the subframe, in which the power headroom report is obtained, and the virtual power headroom being for at least one another subframe set,

means for performing scheduling for the subframe sets based on the power headroom report.

43. A computer program product including a program for a processing device, comprising software code portions for performing the steps of any one of claims 1 to 20 when the program is run on the processing device.

44. The computer program product according to claim 43, wherein the computer program product comprises a computer-readable medium on which the software code portions are stored .

45. The computer program product according to claim 43, wherein the program is directly loadable into an internal memory of the processing device.

46. A user device, comprising

an apparatus according to any one of claims 21 to 36 and 41.

47. A node, comprising :

an apparatus according to claim 37 to 40 and 42.