WO2019157738A1

WO2019157738A1 - Method, apparatus and computer program

Info

Publication number: WO2019157738A1
Application number: PCT/CN2018/076880
Authority: WO
Inventors: Samuli Turtinen; Chunli Wu
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2018-02-14
Filing date: 2018-02-14
Publication date: 2019-08-22
Also published as: CN111903159A; CN111903159B

Abstract

There is provided a method comprising providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, determining if there is a second carrier associated with the cell and, if so, providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

Description

METHOD, APPARATUS AND COMPUTER PROGRAM

Field

The present application relates to a method, apparatus, system and computer program and in particular but not exclusively to reporting power headroom with supplementary uplink (SUL) .

Background

A communication system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided for example by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, video, electronic mail (email) , text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

In a wireless communication system at least a part of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems comprise public land mobile networks (PLMN) , satellite based communication systems and different wireless local networks, for example wireless local area networks (WLAN) . The wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems.

A user can access the communication system by means of an appropriate communication device or terminal. A communication device of a user may be referred to as user equipment (UE) or user device. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station, for example a base station of a cell, and transmit and/or receive communications on the carrier.

The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. One example of a communications system is UTRAN (3G radio) . Other examples of communication systems are the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology and so-called 5G or New Radio (NR) networks. NR is being standardized by the 3rd Generation Partnership Project (3GPP) .

Summary

In a first aspect there is provided a method comprising providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, determining if there is a second carrier associated with the cell and, if so, providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The second uplink carrier may be configured for a sounding reference signal transmission.

The power headroom information may comprise a power headroom report.

The second control element may comprise an indication that it comprises power headroom information for the second uplink carrier.

The indication may comprise one of a logical channel identity, a reserved bit or the position of the second control element relative to the first control element.

The second uplink carrier may be a supplementary uplink carrier.

In a second aspect there is provided a method comprising receiving, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell and, if there is a second uplink carrier associated with the cell, receiving, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In a third aspect there is provided an apparatus, said apparatus comprising means for providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, means for determining if there is a second carrier associated with the cell and means for, if so, providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In a fourth aspect there is provided an apparatus, said apparatus comprising means for receiving, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell and means for, if there is a second uplink carrier associated with the cell, receiving, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In a fifth aspect, there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to

provide, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, determine if there is a second carrier associated with the cell and, if so, provide, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In a sixth aspect, there is provided an apparatus comprising at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to receive, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, and, if there is a second uplink carrier associated with the cell, receive, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In a seventh aspect, there is provided a computer program embodied on a non-transitory computer-readable storage medium, the computer program comprising program code for controlling a process to execute a process, the process comprising providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, determining if there is a second carrier associated with the cell and, if so, providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In an eighth aspect there is provided a computer program embodied on a non-transitory computer-readable storage medium, the computer program comprising program code for controlling a process to execute a process, the process comprising receiving, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell and, if there is a second uplink carrier associated with the cell, receiving, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

The power headroom information may comprise a power headroom report.

The second uplink carrier may be a supplementary uplink carrier.

In a ninth aspect there is provided a computer program product for a computer, comprising software code portions for performing the steps the method of the first aspect or second aspect when said product is run on the computer.

In the above, many different embodiments have been described. It should be appreciated that further embodiments may be provided by the combination of any two or more of the embodiments described above.

Description of Figures

Embodiments will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 shows a schematic diagram of an example communication system comprising a base station and a plurality of communication devices;

Figure 2 shows a schematic diagram of an example mobile communication device;

Figure 3 shows a schematic diagram of an example control apparatus;

Figure 4 shows a schematic diagram of an example SUL architecture;

Figure 5 shows an example of a media access control control element (MAC CE) ;

Figure 6 shows an example of a MAC CE for SUL;

Figure 7a shows an example of a MAC CE for SUL;

Figure 7b shows an example of a MAC CE for SUL;

Figure 7c shows an example of a MAC CE for SUL;

Figure 8 shows a flowchart of an example method according to an embodiment;

Figure 9 shows a flowchart of an example method according to an embodiment;

Figure 10 shows an example of a MAC CE according to an embodiment;

Figure 11 shows an example of a MAC CE according to an embodiment.

Detailed description

Before explaining in detail the examples, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 3 to assist in understanding the technology underlying the described examples.

In a wireless communication system 100, such as that shown in figure 1, mobile communication devices or user equipment (UE) 102, 104, 105 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller. In Figure 1

control apparatus

108 and 109 are shown to control the respective macro

level base stations

106 and 107. The control apparatus of a base station can be interconnected with other control entities. The control apparatus is typically provided with memory capacity and at least one data processor. The control apparatus and functions may be distributed between a plurality of control units. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller.

In Figure 1

base stations

106 and 107 are shown as connected to a wider communications network 113 via gateway 112. A further gateway function may be provided to connect to another network.

The

smaller base stations

116, 118 and 120 may also be connected to the network 113, for example by a separate gateway function and/or via the controllers of the macro level stations. The

base stations

116, 118 and 120 may be pico or femto level base stations or the like. In the example,

stations

116 and 118 are connected via a gateway 111 whilst station 120 connects via the controller apparatus 108. In some embodiments, the smaller stations may not be provided.

Smaller base stations

116, 118 and 120 may be part of a second network, for example WLAN and may be WLAN Aps.

The

communication devices

102, 104, 105 may access the communication system based on various access techniques, such as code division multiple access (CDMA) , or wideband CDMA (WCDMA) . Other non-limiting examples comprise time division multiple access (TDMA) , frequency division multiple access (FDMA) and various schemes thereof such as the interleaved frequency division multiple access (IFDMA) , single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA) , space division multiple access (SDMA) and so on.

An example of wireless communication systems are architectures standardized by the 3rd Generation Partnership Project (3GPP) . A latest 3GPP based development is often referred to as the long term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. The various development stages of the 3GPP specifications are referred to as releases. More recent developments of the LTE are often referred to as LTE Advanced (LTE-A) . The LTE employs a mobile architecture known as the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) . Base stations of such systems are known as evolved or enhanced Node Bs (eNBs) and provide E-UTRAN features such as user plane Packet Data Convergence/Radio Link Control/Medium Access Control/Physical layer protocol (PDCP/RLC/MAC/PHY) and control plane Radio Resource Control (RRC) protocol terminations towards the communication devices. Other examples of radio access system comprise those provided by base stations of systems that are based on technologies such as wireless local area network (WLAN) and/or WiMax (Worldwide Interoperability for Microwave Access) . A base station can provide coverage for an entire cell or similar radio service area.

An example of a suitable communications system is the 5G or NR concept. Network architecture in NR may be similar to that of LTE-advanced. Base stations of NR systems may be known as next generation Node Bs (gNBs) . Changes to the network architecture may depend on the need to support various radio technologies and finer QoS support, and some on-demand requirements for e.g. QoS levels to support QoE of user point of view. Also network aware services and applications, and service and application aware networks may bring changes to the architecture. Those are related to Information Centric Network (ICN) and User-Centric Content Delivery Network (UC-CDN) approaches. NR may use multiple input -multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept) , including macro sites operating in co-operation with smaller stations and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates.

Future networks may utilise network functions virtualization (NFV) which is a network architecture concept that proposes virtualizing network node functions into “building blocks” or entities that may be operationally connected or linked together to provide services. A virtualized network function (VNF) may comprise one or more virtual machines running computer program codes using standard or general type servers instead of customized hardware. Cloud computing or data storage may also be utilized. In radio communications this may mean node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of labour between core network operations and base station operations may differ from that of the LTE or even be non-existent.

A possible mobile communication device will now be described in more detail with reference to Figure 2 showing a schematic, partially sectioned view of a communication device 200. Such a communication device is often referred to as user equipment (UE) or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’ , a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle) , personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email) , text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information.

A mobile device is typically provided with at least one data processing entity 201, at least one memory 202 and other possible components 203 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 204. The user may control the operation of the mobile device by means of a suitable user interface such as key pad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 208, a speaker and a microphone can be also provided. Furthermore, a mobile communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto.

The mobile device 200 may receive signals over an air or radio interface 207 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 2 transceiver apparatus is designated schematically by block 206. The transceiver apparatus 206 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

Figure 3 shows an example of a control apparatus for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a RAN node, e.g. a base station, eNB or gNB or a node of a core network such as an MME or S-GW, or a server or host. The method may be implanted in a single control apparatus or across more than one control apparatus. The control apparatus may be integrated with or external to a node or module of a core network or RAN. In some embodiments, base stations comprise a separate control apparatus unit or module. In other embodiments, the control apparatus can be another network element such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such a control apparatus as well as a control apparatus being provided in a radio network controller. The control apparatus 300 can be arranged to provide control on communications in the service area of the system. The control apparatus 300 comprises at least one memory 301, at least one

data processing unit

302, 303 and an input/output interface 304. Via the interface the control apparatus can be coupled to a receiver and a transmitter of the base station. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head.

To improve uplink (UL) coverage for high frequency scenarios, supplementary uplink (SUL) may be configured. SUL is modelled as another UL carrier of the same cell (i.e., there is only one DL carrier associated with the cell) .

Figure 4 shows a schematic representation of SUL, in which a UE 200 is configured with two UL carriers for one DL of the same cell 410.

Either one of the UL carriers at a time may be used for UL transmissions. An exception to this is the sounding reference signal (SRS) which may be transmitted at the same time in a carrier (UL carrier or SUL carrier) while data is being transmitted on the other carrier. Uplink transmissions on the two ULs in SUL are controlled by the network (e.g. by L1 signalling) to avoid overlapping physical uplink shared channel (PUSCH) /physical uplink control channel (PUCCH) transmissions in time. Overlapping transmissions on PUSCH may be avoided through scheduling while overlapping transmissions on PUCCH may be avoided through configuration (i.e., PUCCH may only be configured for only one of the two ULs of the cell) . In addition, initial access is supported in each of the two ULs.

In SUL, the default location of the PUSCH is the same carrier as used by PUCCH. UE specific RRC signalling may be used to (re-) configure the location of the PUCCH, either on the SUL carrier or on a non-SUL UL carrier in a SUL band combination.

SRS may be configured on the SUL carrier and non-SUL UL carrier, irrespective of the carrier configuration for PUSCH and PUCCH. SRS related RRC parameters may be independently configured for SRS on the SUL carrier and SRS on the non-SUL UL carrier in the SUL band combination. The RRC configuration may include PUSCH, SRS and power control info per UL carrier, and dedicated PUCCH for a single UL carrier.

That is, the SRS transmission may happen independently of the carrier (UL or SUL) configuration transmitting PUSCH and PUCCH and hence, may happen at the same time.

Power headroom (PH) indicates how much transmission power is left for a UE to use in addition to the power being used by current transmission. It has been agreed that PH may be reported for the SRS transmissions to aid the scheduler operation. SRS PH reporting for an uplink where PUSCH is not configured (known as Type 3 PH reporting) may be supported. SRS virtual PHR reporting may be based on one SRS resource configured by the NW.

Power headroom reports (PHR) may be included in a MAC CE. Type 1 PH is used for PUSCH transmission while Type 3 PH is used for SRS transmission (Type 2 is used for PUSCH and PUCCH transmissions) . The headroom is reported either based on real transmission or virtual transmission (which is calculated based on reference format when no real transmission happens during the transmission the PHR is reported) .

Figure 5 shows an example PHR MAC control element (CE) reporting Type 1 and Type 2 PH with the highest Scelllndex of Scell with configured uplink is less than 8. The PHR MAC CEs may be defined as follows:

C _i: this field indicates the presence of a PH field for the secondary cell (Scell) with Scelllndex i. The C _i field set to “1” indicates that a PH field for the Scell with Scelllndex i is reported. The C _i field set to “0” indicates that a PH field for the Scell with Scelllndex i is not reported. PH for primary cell (Pcell) is always present without a bit in the bitmap;

R: reserved bit, set to “0” ;

V: this field indicates if the PH value is based on a real transmission or a reference format. For Type 1 PH, V=0 indicates real transmission on PUSCH and V=1 indicates that a PUSCH reference format is used. For Type 2 PH, V=0 indicates real transmission on PUCCH and V=1 indicates that a PUCCH reference format is used. For Type 3 PH, V=0 indicates real transmission on SRS and V=1 indicates that an SRS reference format is used. Furthermore, for Type 1, Type 2, and Type 3 PH, V=0 indicates the presence of the octet containing the associated P _CMAX, c field, and V=1 indicates that the octet containing the associated P _CMAX, c field is omitted;

Power Headroom (PH) : this field indicates the power headroom level. The length of the field is 6 bits.

P: this field indicates whether the MAC entity applies power backoff due to power management. The MAC entity shall set P=1 if the corresponding P _CMAX, c field would have had a different value if no power backoff due to power management had been applied;

P _CMAX, c: if present, this field indicates the P _CMAX, c or

used for calculation of the preceding PH field.

There may be a need for a separate PH report (PHR) format for the SUL case as SRS transmission may be sent in SUL/UL carrier while the other carrier transmits PUSCH. Currently, simultaneous Type 1 and Type 3 power headroom (PH) may not be reported together for the same cell. The capability of reporting Type 1 PH and Type 3 PH in the same cell at the same time would be desirable.

Several options have been proposed.

In the case where both UL and SUL may be configured with PUSCH, a new PHR MAC CE format has been proposed. Figure 6 shows an example PHR MAC CE format for the support of per UL carrier PH reporting.

As the NW may be aware of whether a SUL carrier is configured for a Scell of a UE, a bitmap indication for the existence of the PH for specific UL carrier may not be required. The UL carriers for a certain cell are stacked based on a pre-specified ordering, e.g. SUL first and non-SUL next, etc., which is similar to type 2 PH. That is, in this option, the PHs for the two UL carriers for the same Scell are stacked according to the UL carrier index, which is known to the network.

However, in this proposal, a PHR format is created for the purpose of enabling simultaneous Type 1 and/or Type 3 PH for SUL. The PHR format may have the overhead of double PH for single cell when SUL is configured or there may be ambiguity in the NW when the double PH is reported during RRC reconfiguration (e.g., dependent on whether the SRS is configured to be reported on UL/SUL when other carrier is in use) .

In an alternative proposal, since the SUL carrier and non-SUL carrier share the same cell index (due to the fact they belong to the same serving cell) , the “R” bit in the current PHR format in the octet of P _CMAX, c may be used to indicate whether one more type1 PHR is followed for the same serving cell or not. The order of the carriers may be fixed in the specification.

An example Type1 PHR format for Pcell is shown in Figure 7a, and an example Type 1 format for PSCell shown in Figure 7b. An indicator field “E” is used to indicate the presence of a further type1 PHR for the same serving cell.

When one of the UL is configured with PUSCH and another is configured with SRS the same approach may be applicable for the PHR MAC CE design. An indication field may be added to indicate the presence of

type

1 or 3 PH. Figure 7c shows an example MAC CE based on this approach. The indicator bit is 1, indicating the corresponding PH is present for the cell.

In this case, an additional PHR format may be defined to carry Type 1 PH and Type 3 PH for the same cell. When PHR is triggered, Type 1 PH is always present in the MAC CE, while whether Type 3 PH is present depends on if SRS transmission is configured on a different carrier. An indicator field may be added to indicate the presence of Type 3 PH. To save bits, an R bit may be used. A length field L may be added in the MAC sub-header to indicate the length of the MAC CE.

In the examples described with reference to Figures 7a to 7c, Type 1 PH is placed first and is always present; Type x PH (x=1 or 3) follows type 1 PH and may not always be present.

An indicator field (e.g. “R1” or “E” ) may be added in the P _cmax byte of type 1 PH to indicate the presence of Type x PH (x = 1 or 3) .

However, in the approach described with reference to Figures 7a to 7c, a PHR format is created for the purpose of enabling simultaneous Type 3 PH for SUL. Since the indicator field is always required, whether or not a further PHR is reported for the same cell, the optimization that is currently in the MAC specification where the byte including P _cmax may be omitted if virtual PH is reported cannot be utilized. That is, this option may increase overhead.

Another approach for the PHR MAC CE design may be to reuse the current PHR format of DC (multiple entry PHR MAC CE) . For the SUL carrier, a separate Scelllndex may be configured. There may not be enough Scell indexes to cover all combinations. Since the SUL and UL carrier are from the same cell, a different cell index may not be appropriate since the bitmap of the PHR format would also need to be extended.

Figure 8 shows a flowchart of an example method which may allow simultaneous Type 1 and Type 3 PH reporting for a single serving cell.

In a first step, S1, the method comprises providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell.

In a second step, S2, the method comprises determining if there is a second carrier associated with the cell. This step may additionally comprise determining if the second uplink carrier is configured with SRS resources.

If so, in a third step, S3, the method comprises providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements. The first and second control elements may be MAC CE. The separate MAC CEs may be comprised in the same MAC PDU.

Figure 9 shows flowchart of an example method which may allow simultaneous Type 1 and Type 3 PH reporting for a single serving cell

In a first step, T1, the method comprises receiving, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a celt.

In a second step, T2, the method comprises, if there is a second uplink carrier associated with the cell, receiving, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements. The first and second control elements may be MAC CE. The separate MAC CEs may be comprised in the same MAC PDU

A method as described with reference to Figure 8 may be performed at a user equipment. A method as described with reference to Figure 9 may be performed at a node of a network, e.g. eNB, gNB or cloud RAN.

The second uplink carrier may be an SUL carrier. The second uplink carrier may be configured for SRS.

A method as described with reference to Figures 8 and 9 provides separate MAC CEs for the Type 1 (including the ‘general PHR’ for all the cells, i.e. the PHs without the Type 3 PHs for cells configured with SUL) and Type 3 PHs (reported only for serving ceils as required) . The same MAC CE format may be applied for both.

A separate MAC CE with the same format may be defined for SUL of all cells without impact on the original MAC CE without SUL. The separate MAC CE may contain either Type 1 PH or Type 3 PH of the SUL carrier, depending on if PUSCH or SRS is configured on the SUL carrier, and/or real or virtual value depending on if there is actual PUSCH/SRS transmission when the PHR is reported. The MAC CE without SUL does not report type 1 for PUSCH, or type 3 for SRS, if PUSCH or SRS is not configured on the UL carrier of the serving cell.

A UE reports the Type 3 PH for a given serving cell if the uplink carrier (UL or SUL) is configured with SRS reporting and that carrier is not the currently “active” one, i.e. without PUSCH/PUCCH transmission (since for the active carrier the NW can determine the PH based on the Type 1 report for PUSCH) .

The second control element may comprise an indication that it comprises power headroom information for the second uplink carrier. The indication may comprise one of a logical channel identity, a reserved bit or the position of the second control element relative to the first control element.

For example, the NW may determine whether the MAC CE is for general PHR or solely for Type 3 PHs or alternatively for PHR for SUL based on a separate LCID value indicated, the reserved bit in the cell index space of the PHR format or the order in which the MAC Ces are multiplexed within the MAC PDU. For instance, the general PHR may always multiplexed first and a second PH MAC CE will follow if any activated serving cell is configured with SUL.

The PHR MAC CE for SUL may be indicated with separate LCID and bitmap only when needed for the cells configured with SUL.

The existence of the Pcell Type 3 PH report could also be explicitly indicated based on the R bit for the cell indexes.

The general PHR format may be applied for Type 3 PH reporting as well. Figure 10 shows a multiple entry PHR MAC CE format for at most seven Scells for reporting Type3 PH. The format is based on the MAC CE format as described with reference to 5.

Using separate MAC CE for SUL means that type 3 PH may be reported only when there is a need. The P _cmax field may always be omitted if the virtual PH is reported (both for general PHR and Type 3 dedicated PHR) since an indication of further PHR is not required. This may mitigate the introduced overhead.

The same Scell index can be used to indicate the UL and SUL of the same cell (given that the reports are separate) .

No ambiguity may be introduced in the NW when, and for which serving cells, the UE will report both Type 1 and Type 3 simultaneously.

Figure 11 shows an example of a multiple entry PHR MAC CE with the highest Scelllndex of Scell with configured uplink less than 8 for Type 1/3 PH reporting with SUL. The MAC CE in Figure 11 is an example of PHR format with the PH for SUL in a separate MAC CE, including type 1 PH and type 3 PH for SUL, depending on whether PUSCH or SRS is configured on the SUL (x=1 or 3) . The PHR for non-SUL carriers may be included in a separate PHR MAC CE in the same MAC PDU. When type 1 PH for SUL for a serving cell is included in a PHR MAC CE, it does not need to be included for the other of the MAC CE. Alternatively, virtual PH may be reported for the other MAC CE. When no actual PUSCH transmission is scheduled on both UL and SUL carrier, it can be specified that virtual type 1 is only reported for the UL carrier.

PHR MAC CE format may comprise a bitmap for SCelllndices of different sizes, e.g., 0, 8, or 32.The bitmap may be of different size for the first PHR MAC CE and the second PHR MAC CE.

Separate PHR MAC CEs in the same MAC PDU may be applicable for other use cases as well, e.g. for sTTI (shorter transmission time interval) , when there are multiple PH of the same type to be reported for the same cell, even if they are on the same carrier. In this example, an example method may comprise providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first TTI of a carrier, determining if a second TTI on the carrier requires a different PH type to a first TTI and, if so, providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second TTI, wherein the first control element and the second control element are separate control elements.

The method may be implemented in a user equipment as described with reference to Figure 2 or a control apparatus as described with reference to Figure 3. Control functions may comprise providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell, determining if there is a second carrier associated with the cell and, if so, providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

Alternatively, or in addition, control functions may comprise receiving, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell and, if there is a second uplink carrier associated with the cell, receiving, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.

It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and/or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

It is noted that whilst embodiments have been described in relation to SUL in NR, similar principles can be applied in relation to other networks and communication systems where a serving cell has more than one uplink carrier or more than one type of PH is to be reported for a serving cell. Therefore, although certain embodiments were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable forms of communication systems than those illustrated and described herein.

It is also noted herein that while the above describes example embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The embodiments of this invention may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out embodiments. The one or more computer-executable components may be at least one software code or portions of it.

Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) , application specific integrated circuits (ASIC) , FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention as defined in the appended claims. Indeed there is a further embodiment comprising a combination of one or more embodiments with any of the other embodiments previously discussed.

Claims

A method comprising:

providing, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell;

determining if there is a second carrier associated with the cell; and, if so,

providing, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.
A method according to claim 2, wherein the second uplink carrier is configured for a sounding reference signal transmission.
A method according to claim 1 or claim 2, wherein the power headroom information comprises a power headroom report.
A method according to any of claims 1 to 3 wherein the second control element comprises an indication that it comprises power headroom information for the second uplink carrier.
A method according to claim 4, wherein the indication comprises one of a logical channel identity, a reserved bit or the position of the second control element relative to the first control element.
A method according to any of claims 1 to 5, wherein the second uplink carrier is a supplementary uplink carrier.
A method comprising:

receiving, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell; and

if there is a second uplink carrier associated with the cell, receiving, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.
A method according to claim 7, wherein the second uplink carrier is configured for a sounding reference signal transmission.
A method according to claim 7 or claim 8, wherein the power headroom information comprises a power headroom report.
A method according to any of claims 7 to 9 wherein the second control element comprises an indication that it comprises power headroom information for the second uplink carrier.
A method according to claim 10, wherein the indication comprises one of a logical channel identity, a reserved bit or the position of the second control element relative to the first control element.
A method according to any of claims 7 to 11, wherein the second uplink carrier is a supplementary uplink carrier.
An apparatus comprising means for performing a method according to any one of claims 1 to 6 or 7 to 12.
A computer program product for a computer, comprising software code portions for performing the steps of any of claims 1 to 6 or 7 to 12 when said product is run on the computer.
An apparatus comprising:

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

provide, from a user equipment to a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell;

determine if there is a second carrier associated with the cell; and, if so,

provide, from the user equipment to the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.
An apparatus comprising:

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

receive, from a user equipment at a network, a first control element, the first control element comprising power headroom information for a first uplink carrier associated with a cell;

and, if there is a second uplink carrier associated with the cell, receive, from the user equipment at the network, a second control element, the second control element comprising power headroom information for the second uplink carrier, wherein the first control element and the second control element are separate control elements.