WO2023249523A1

WO2023249523A1 - Transmission of nr control information in an lte downlink subframe

Info

Publication number: WO2023249523A1
Application number: PCT/SE2022/050626
Authority: WO
Inventors: Saad Naveed AHMED; Kevin Smith
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-06-22
Filing date: 2022-06-22
Publication date: 2023-12-28

Abstract

There is provided mechanisms for transmission of NR control information in an LTE downlink subframe. A method is performed by a network node. The method comprises obtaining information that neither LTE PHICH resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe. The method comprises, in response thereto, configuring resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe. Which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not. The method comprises initiating transmission of the LTE downlink subframe.

Description

TRANSMISSION OF NR CONTROL INFORMATION IN AN LTE DOWNLINK SUBFRAME

TECHNICAL FIELD

Embodiments presented herein relate to a method, a network node, a computer program, and a computer program product for transmission of New Radio control information in a Long Term Evolution downlink subframe.

BACKGROUND

NR (New Radio) is the air interface specified for the fifth generation (5G) telecommunications systems according to the third generation partnership project (3GPP). NR might be regarded as a further development, with enhanced functionality and performance, of the Long Term Evolution (LTE) air interface.

Mobile network operators that deploy NR typically have access to, or have been allocated, existing frequency spectrum on multiple frequency bands where LTE signalling is currently deployed. Initially, the fraction of NR capable user equipment might be limited compared to LTE capable user equipment and therefore a large part of the existing frequency spectrum might still need to be allocated for LTE signalling.

There are several architecture options for how to deploy NR together with LTE.

One option is to use LTE as the main air interface whilst NR is added using dual connectivity in non-standalone mode. With dual connectivity, both the LTE air interface and the NR air interface can be used in parallel for data transmission (and reception). In the downlink (i.e., in the direction from radio access network node on the network side towards user equipment on the user side) the data transmission is split at the Packet Data Convergence Protocol (PDCP) layer and can use either one of the air interfaces (i.e., LTE or NR) or both. In uplink (i.e., in the direction from user equipment on the user side towards radio access network node on the network side) the data received from the two air interfaces are combined in the PDCP layer at the radio access network node.

To have an efficient frequency spectrum utilization, it is possible to overlay an NR carrier in the same frequency spectrum as an LTE carrier. This is made possible by flexible locations of control channels and signals, and by rate matching around reference signals, such as cell-specific reference signal (CRS), channel state information reference signal (CSI-RS), and synchronization signals (such as primary synchronization signal (PSS), secondary synchronization signal (SSS)), and physical broadcast channel (PBCH) that are transmitted in an LTE carrier. Hence, different CRS port configurations could be used for such rate matching.

A side effect of dynamically sharing the spectrum using CRS rate matching is that the NR Physical Downlink Control Channel (PDCCH) becomes constrained to only the symbols where CRS does not exist. This significantly caps the number of simultaneous scheduled user equipment and hampers the efficient use of the spectrum.

Hence, there is still a need for improved joint downlink NR and LTE transmissions.

SUMMARY

An object of embodiments herein is to provide efficient joint downlink NR and LTE transmission that does not suffer from the issues noted above, or at least where the issues noted above are mitigated or reduced.

According to a first aspect there is presented a method for transmission of NR control information in an LTE downlink subframe. The NR control information is to be transmitted in NR PDCCH resource elements (REs). The LTE downlink subframe comprises LTE Physical Control Format Indicator Channel (PCFICH) resource element groups (REGs) in which LTE control format information is to be transmitted. The method is performed by a network node. The method comprises obtaining information that neither LTE Physical channel Hybrid automatic repeat request Indicator Channel (PHICH) resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe. The method comprises, in response thereto, configuring resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe. Which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not. The method comprises initiating transmission of the LTE downlink subframe. According to a second aspect there is presented a network node for transmission of NR control information in an LTE downlink subframe. The NR control information is to be transmitted in NR PDCCH REs. The LTE downlink subframe comprises LTE PCFICH REGs in which LTE control format information is to be transmitted. The network node comprises processing circuitry. The processing circuitry is configured to cause the network node to obtain information that neither LTE PHICH resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe. The processing circuitry is configured to cause the network node to, in response thereto, configure resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe. Which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not. The processing circuitry is configured to cause the network node to initiate transmission of the LTE downlink subframe.

According to a third aspect there is presented a network node for transmission of NR control information in an LTE downlink subframe. The NR control information is to be transmitted in NR PDCCH REs. The LTE downlink subframe comprises LTE PCFICH REGs in which LTE control format information is to be transmitted. The network node comprises an obtain module configured to obtain information that neither LTE PHICH resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe. The network node comprises a configure module configured to, in response thereto, configure resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe. Which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not. The network node comprises an initiate module configured to initiate transmission of the LTE downlink subframe. According to a fourth aspect there is presented a computer program for transmission of NR control information in an LTE downlink subframe, the computer program comprising computer program code which, when run on a network node, causes the network node to perform a method according to the first aspect.

According to a fifth aspect there is presented a computer program product comprising a computer program according to the fourth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium could be a non-transitory computer readable storage medium.

Advantageously, these aspects provide efficient joint downlink NR and LTE transmission.

Advantageously, these aspects provide joint downlink NR and LTE transmission that does not suffer from the issues noted above.

Advantageously, these aspects increase the NR PDCCH capacity.

Advantageously, these aspects provide improved NR PDSCH utilization with type A PDSCH.

Advantageously, these aspects require lower computational complexity than required for using type B PDSCH.

Advantageously, these aspects enable minimal impact on the LTE performance.

Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, module, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic diagram illustrating a communications network according to embodiments;

Fig. 2 schematically illustrates time/frequency resources in a time/frequency resource grid according to an example;

Fig. 3 is a flowchart of methods according to embodiments;

Fig. 4 is a block diagram of a network node according to an embodiment;

Figs. 5, 6, and 7 are signalling diagrams according to embodiments;

Fig. 8 is a schematic diagram showing functional units of a network node according to an embodiment;

Fig. 9 is a schematic diagram showing functional modules of a network node according to an embodiment;

Fig. 10 shows one example of a computer program product comprising computer readable storage medium according to an embodiment;

Fig. 11 is a schematic diagram illustrating a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments; and

Fig. 12 is a schematic diagram illustrating host computer communicating via a radio base station with a terminal device over a partially wireless connection in accordance with some embodiments.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

Fig. 1 is a schematic diagram illustrating a communications network loo where embodiments presented herein can be applied. The communications network 100 comprises a network node 200 configured to provide network access to user equipment, as represented by user equipment 1503,150b, 150c, in a radio access network 110. The radio access network 110 is operatively connected to a core network 120. The core network 120 is in turn operatively connected to a service network 130, such as the Internet. The user equipment 1503,150b, 150c are thereby enabled to, via the network node 200, access services of, and exchange data with, the service network 130. Some of the user equipment 1503,150b, 150c might be configured to communicate with the network node 200 using LTE signalling, some of the user equipment 1503,150b, 150c might be configured to communicate with the network node 200 using NR signalling, and some of the user equipment 1503,150b, 150c might be configured to communicate with the network node 200 using both LTE signalling and NR signalling. User equipment 1503,150b, 150c configured to communicate with the network node 200 using LTE signalling are hereinafter denoted LTE user equipment. User equipment 1503,150b, 150c configured to communicate with the network node 200 using NR signalling are hereinafter denoted NR user equipment. User equipment 1503,150b, 150c configured to communicate with the network node 200 using both LTE signalling and NR signalling are hereinafter denoted LTE/NR user equipment.

The network node 200 comprises, is collocated with, is integrated with, or is in operational communications with, an antenna system comprising co-sited antenna arrays 140a, 140b. Each of the antenna arrays 140a, 140b might comprise a plurality of individual antennas, or antenna elements. In some implementations, one antennas antenna array 140a might be configured for LTE signalling whereas the other antennas antenna array 140b might be configured for NR signalling. In other implementations, both antenna arrays 140a, 140b are configured for both LTE signalling and NR signalling. Examples of network nodes 200 are radio access network nodes, radio base stations, base transceiver stations, Node Bs, evolved Node Bs, gNBs, access points, access nodes, and integrated access and backhaul nodes. Examples of user equipment 150a, 150b, 150c are terminal devices, wireless devices, mobile stations, mobile phones, handsets, wireless local loop phones, smartphones, laptop computers, tablet computers, network equipped sensors, network equipped vehicles, and so-called Internet of Things devices.

As noted above there is still a need for improved joint downlink NR and LTE transmissions.

One technique to address this issue could be to utilize advanced user equipment capabilities to decode the PDSCH of type B to increase PDCCH capacity. However, besides its effectiveness depending on the ratio of supportive user equipment, this might be considered as a complicated technique that also comes with NR performance drawbacks.

The embodiments disclosed herein relate to techniques for transmission of NR control information in an LTE downlink subframe that address at least some of these issues. In order to obtain such techniques there is provided a network node 200, a method performed by the network node 200, a computer program product comprising code, for example in the form of a computer program, that when run on a network node 200, causes the network node 200 to perform the method.

At least some of the herein disclosed embodiments enable the NR PDCCH capacity to be increased without compromising LTE PDSCH capacity and without relying on additional user equipment capabilities.

The herein disclosed embodiments are based on utilizing LTE Physical Control Format Indicator Channel (PCFICH) resource element groups (REGs), and possibly also the CRS, of the LTE downlink subframe for transmission of NR control information in an LTE downlink subframe. This is possible when neither LTE Physical channel Hybrid automatic repeat request Indicator Channel (PHICH) resources are needed, nor any LTE PDCCH resources for high priority traffic are needed. Fig. 2 illustrates time/frequency resources in a time/frequency resource grid io with allocation of four LTE PCFICH REGs. The LTE PCFICH carries the number of symbols that can be used for LTE control channels (such as LTE PDCCH and LTE PHICH; but the duration of the PHICH is not specified by the LTE PCFICH). The LTE PCFICH is mapped to the first orthogonal frequency-division multiplexing (OFDM) symbol (i.e., the symbol with index o) in each of the LTE downlink subframes. The LTE user equipment decodes the LTE PCFICH to determine how many OFDM symbols are assigned for the LTE PDCCH. The LTE PCFICH occupy 16 data sub-carriers of the first OFDM symbol of the LTE downlink subframe. The LTE PCFICH data is carried by 4 REGs and these four REGs are evenly distributed across the whole system bandwidth. The exact position of each of the PCFICH REGs is determined by the cell identity and the cell bandwidth.

Fig. 3 is a flowchart illustrating embodiments of methods for transmission of NR control information in an LTE downlink subframe. The NR control information is to be transmitted in NR PDCCH REs. The LTE downlink subframe comprises LTE PCFICH REGs in which LTE control format information is to be transmitted. It is here understood that also other physical channels, such as PHICH, PDCCH, PDSCH, as well as various reference signals, such as CRS, etc. might be transmitted in the first symbol of the LTE downlink subframe. The methods are performed by the network node 200. The methods are advantageously provided as computer programs 1020.

In general terms, LTE and NR are sharing a common spectrum. Particularly, in some embodiments, the NR control information and the LTE control format information is to be transmitted on at least partly overlapping frequency carriers. Further, the NR user equipment are configured with either no CRS rate matching or CRS rate matching using lesser than the full LTE bandwidth.

The network node 200 determines that neither LTE PHICH resources are needed, nor any LTE PDCCH resources for high priority traffic are needed. This is accomplished by the network node 200 performing step S102.

S102: The network node 200 obtains information that neither LTE PHICH resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe. The network node 200 in response thereto, i.e., in response to having obtained the information in step S102, performs step S104.

S104: The network node 200 configures resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe.

In this respect, resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information might be configured not only within the LTE PCFICH REGs of the LTE downlink subframe, but at least overlapping with the LTE PCFICH REGs of the LTE downlink subframe

How the first (OFDM) symbol (i.e., the (OFDM) symbol with index o) in the LTE downlink subframe can be utilized for transmission of the NR control information depends on whether all LTE PCFICH REGs overlap with NR PDCCH REs in first symbol or not. Hence, which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not.

Transmission of the LTE downlink subframe is then initiated, as in step S106.

S106: The network node 200 initiates transmission of the LTE downlink subframe.

Embodiments relating to further details of transmission of NR control information in an LTE downlink subframe as performed by the network node 200 will now be disclosed.

There may be different ways for the network node 200 to in step S104 configure resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe, depending on the overlap between the LTE PCFICH REGs and the NR PDCCH REs in the first symbol. Different embodiments relating thereto will now be described in turn. In some aspects it is assumed that all the LTE PCFICH REGs overlap with NR PDCCH REs in the first symbol. At least one of the LTE PCFICH REGs is selected for transmission of the LTE control format information whilst others are muted. In particular, in some embodiments, when all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the network node 200 is configured to perform (optional) steps SiO4aa and SiO4ab as part of step S104.

SiO4aa: The network node 200 selects at least one of the LTE PCFICH REGs for transmission of the LTE control format information and determines muting LTE transmission in at least one other of the LTE PCFICH REG.

SiO4ab: The network node 200 selects the at least one of the LTE PCFICH REGs for LTE transmission to be used for punctured transmission of the NR control information.

In some aspects, there might not be any overlap between the LTE PCFICH REGs and the NR PDCCH. Then neither muting of the LTE PCFICH nor puncturing of the NR PDCCH is needed. Only CRS overlapping with the NR PDCCH might then be muted.

In some aspects it is assumed that not all the LTE PCFICH REGs overlap with NR PDCCH REs in the first symbol. At least one of the LTE PCFICH REGs that does not overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe is selected for transmission of the LTE control format information. In particular, in some embodiments, when at least one of the LTE PCFICH REGs does not overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the network node 200 is configured to perform (optional) steps SiO4ba and SiO4bb as part of step S104.

SiO4ba: The network node 200 selects the at least one of the LTE PCFICH REGs for transmission of the LTE control format information and determines muting LTE transmission in at least one of the LTE PCFICH REGs and CRS that overlap with the NR PDCCH REs in the symbol at index o. Si04bb: The network node 200 selects the at least one of the LTE PCFICH REGs where the LTE PCFICH REGs do not overlap with the NR PDCCH REs in the symbol at index o for transmission of the NR control information.

Information of the configuration might be provided to schedulers of the LTE transmission and of the NR transmission. In particular, in some embodiments, the network node 200 is configured to perform (optional) steps Sio6a and Sio6b as part of initiating the transmission of the LTE downlink subframe in step S106.

Sio6a: The network node 200 provides information of the configured resource elements for the LTE transmission to a scheduler (below denoted LTE scheduler 242) of the LTE transmission.

Sio6b: The network node 200 provides information of the configured resource elements for the NR transmission to a scheduler (below denoted NR scheduler 244) of the NR transmission.

In this respect, with reference to steps SiO4aa and SiO4ab, the information in Sio6a might comprise an indication to the LTE scheduler 242 to transmit the selected LTE PCFICH REG and mute the other LTE PCFICH REGs as well as CRS overlapping with the NR PDCCH. Likewise, the information in Sio6b might comprise an indication to the NR scheduler 244 that it can use the first symbol with puncturing of the NR PDCCH REs that overlap the selected LTE PCFICH REGs. Further in this respect, with reference to steps SiO4ba and SiO4bb, the information in Sio6a might comprise an indication to the LTE scheduler 242 which PCFICH REGs to transmit and which mute. Likewise, the information in Sio6b might comprise an indication to the NR scheduler 244 that it can use the first symbol without any puncturing.

The LTE scheduler 242 is thus assumed to receive information regarding the configured resource elements for the LTE transmission.

In some embodiments, the information of the configured resource elements for the LTE transmission further indicates that power is to be transmitted only in the LTE PCFICH REGs selected for transmission of the LTE control format information and the CRS which do not overlap with the NR PDCCH. The LTE scheduler 242 might then signal to its transmitter (below denoted LTE transmitter 246) to transmit power only on the selected LTE PCFICH REGs and CRS which do not overlap with the NR PDCCH in the first symbol.

In some embodiments, the information of the configured resource elements for the LTE transmission further indicates a power boost for the LTE PCFICH REGs selected for transmission of the LTE control format information. The LTE scheduler 242 might then signal to the LTE transmitter 246 to boost transmission power of the LTE PCFICH REGs to compensate for loss of power in other LTE PCFICH REGs.

The NR scheduler 244 is thus assumed to receive information regarding the configured resource elements for the NR transmission.

According to a first example, the NR scheduler 244 might apply a reduction to the signal to interference plus noise ratio (SINR) of the NR PDCCH before performing link adaptation for the NR PDCCH in case the first symbol is allocated with puncturing. In particular, in some embodiments, when any of the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the information of the configured resource elements for the NR transmission further indicates that the SINR level of the NR PDCCH REs is to be reduced. In this respect, the SINR level might be reduced proportionally to the loss of NR PDCCH REs and interference power over the LTE PCFICH REGs where the NR PDCCH is punctured.

According to a second example, the NR scheduler 244 might not transmit any power over the NR PDCCH REs that overlap with the selected LTE PCFICH REGs in case the first symbol is allocated with puncturing. In particular, in some embodiments, the information of the configured resource elements for the NR transmission further indicates that punctured transmission of the NR control information involves muting transmission of the NR control information in the LTE PCFICH REGs selected for transmission of the LTE control format information after mapping the NR control information to physical-layer time/frequency resources. In this respect, both rate matching and puncturing entail transmitting zero power in certain resource elements. However, rate matching maps the channel around the zero-power resource, whilst puncturing maps the channel as usual and then sets the selected resource to zero power. According to a third example, the NR transmitter 248 might transmit power over the first symbol for the NR PDCCH in case of allocation of the first symbol without any puncturing. In particular, in some embodiments, when at least one of the LTE PCFICH REGs does not overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the information of the configured resource elements for the NR transmission further indicates that power is to be transmitted only in the at least one of the LTE PCFICH REGs where the LTE PCFICH REGs and CRS do not overlap with the NR PDCCH REs in the symbol at index o for transmission of the NR control information.

Fig. 4 schematically illustrates a block diagram of a network node 200 having a shared resource allocator 240, an LTE scheduler 242, and an NR scheduler 244, together with an LTE transmitter 246 and an NR transmitter 248. The LTE transmitter 246 might comprise, or be operatively connected to, at least the first antenna array 140a. The NR transmitter 248 might comprise, or be operatively connected to, at least the second antenna array 140b. The shared resource allocator 240 is configured to, based on input from the LTE scheduler 242 and the NR scheduler 244 take a decision in terms of configuring resource elements for transmission of the LTE control format information and CRS on the one side and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe on the other side, as in step S104. Transmission of the LTE downlink subframe, as in step S106, is initiated by the shared resource allocator 240 providing output to the LTE scheduler 242 and the NR scheduler 244. The output to the LTE scheduler 242 is defined by the information in step Sio6a. The output to the NR scheduler 244 is defined by the information in step Sio6b. The LTE scheduler 242 is configured to, based on the output received from the shared resource allocator 240, schedule the LTE transmission and initiate transmission of the LTE transmission from the LTE transmitter 246. The NR scheduler 244 is configured to, based on the output received from the shared resource allocator 240, schedule NR transmission and initiate transmission of the NR transmission from the NR transmitter 248.

Detailed operation of the shared resource allocator 240, the LTE scheduler 242, and the NR scheduler 244 will be disclosed next with reference to Fig. 5, Fig. 6, and Fig. 7. Fig. 5, Fig. 6, and Fig. 7 are signalling diagrams for transmission of NR control information in an LTE downlink subframe as performed by the network node 200 according to at least some of the above disclosed embodiments.

Reference is first made to Fig. 5 which shows the operations performed by the shared resource allocator 240.

S201: The shared resource allocator 240 receives a demand from the LTE scheduler 242 relating to LTE PDCCH resources and LTE PHICH resources, and a demand from the NR scheduler 244 relating to NR PDCCH resources.

S202: The shared resource allocator 240 checks if there is any need for LTE PHICH resources. If yes, step S203 is entered and the first symbol in the LTE downlink subframe is given to the LTE scheduler 242. If no, step S204 is entered and it is checked if there is any need for LTE PDCCH resources for for high priority traffic. If yes, step S203 is entered again and the first symbol in the LTE downlink subframe is given to the LTE scheduler 242. If no, step S205 is entered and it is checked if in the first symbol all LTE PCFICH REGs overlap with NR PDCCH REs. If yes, step S206 is entered and at least one of the LTE PCFICH REGs is selected for transmission of the LTE control format information whilst others of the LTE PCFICH REGs, along with CRS, are muted, as in steps SiO4aa and SiO4ab. If no, step S207 is entered and at least one of the LTE PCFICH REGs that does not overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe is selected for transmission of the LTE control format information, as in steps SiO4ba and SiO4bb.

S208: The first symbol in the LTE downlink subframe is then given to the NR scheduler 244.

S209: Based on the above steps S201-S208 the shared resource allocator 240 takes an allocation decision that is communicated to the LTE scheduler 242 and the NR scheduler 244. Information of the configured resource elements for the LTE transmission is provided to the LTE scheduler 242 and information of the configured resource elements for the NR transmission is provided to the NR scheduler 244.

Reference is next made to Fig. 6 which shows the operations performed by the LTE scheduler 242. S301: The LTE scheduler 242 provides a demand to the shared resource allocator 240 receives relating to LTE PDCCH resources and LTE PHICH resources for the LTE downlink subframe.

S302: The LTE scheduler 242 receives information of configured resource elements for the LTE transmission from the shared resource allocator 240.

S303: The LTE scheduler 242 checks if the first symbol in the LTE downlink subframe is granted for LTE transmission. If yes, step S308 is entered. If no, step

5304 is entered.

S304: The LTE scheduler 242 checks if a partial PCFICH is to be sent. If yes, step

5305 is entered. If no, step S308 is entered.

S305: The LTE scheduler 242 initiates muting of the PCFICH REGs and CRS not selected for transmission.

S306: The LTE scheduler 242 initiates transmission power boosting for the PCFICH REGs selected for transmission.

S307: The LTE scheduler 242 initiates transmission of the partial PCFICH and CRS.

S308: The LTE scheduler 242 initiates transmission of the complete PCFICH.

Step S301 is then entered for the next LTE downlink subframe.

Reference is next made to Fig. 7 which shows the operations performed by the NR scheduler 244.

S401: The NR scheduler 244 provides a demand to the shared resource allocator 240 receives relating to NR PDCCH resources for the LTE downlink subframe.

S402: The NR scheduler 244 receives information of configured resource elements for the NR transmission from the shared resource allocator 240.

S403: The NR scheduler 244 checks if the first symbol in the LTE downlink subframe is granted for NR transmission. If yes, step S404 is entered. If no, step S408 is entered. S404: The NR scheduler 244 checks if puncturing is going to be used. If yes, step S405 is entered. If no, step S407 is entered.

S405: The NR scheduler 244 performs link adaptation to adjust the SINR level of the NR PDCCH.

S406: The NR scheduler 244 initiates puncturing of the NR PDCCH resources that overlap with the LTE PCFICH REGs selected for transmission.

S407: The NR scheduler 244 initiates transmission of the NR PDCCH in the first symbol of the LTE downlink subframe.

S408: The NR scheduler 244 refrains from transmitting any NR PDCCH in the first symbol of the LTE downlink subframe.

Step S401 is then entered for the next LTE downlink subframe.

Fig. 8 schematically illustrates, in terms of a number of functional units, the components of a network node 200 according to an embodiment. Processing circuitry 210 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1010 (as in Fig. 10), e.g. in the form of a storage medium 230. The processing circuitry 210 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry 210 is configured to cause the network node 200 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 230 may store the set of operations, and the processing circuitry 210 may be configured to retrieve the set of operations from the storage medium 230 to cause the network node 200 to perform the set of operations. The set of operations may be provided as a set of executable instructions.

Thus the processing circuitry 210 is thereby arranged to execute methods as herein disclosed. The storage medium 230 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. The network node 200 may further comprise a communications interface 220 at least configured for communications with other entities, functions, nodes, and devices. As such the communications interface 220 may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing circuitry 210 controls the general operation of the network node 200 e.g. by sending data and control signals to the communications interface 220 and the storage medium 230, by receiving data and reports from the communications interface 220, and by retrieving data and instructions from the storage medium 230. Other components, as well as the related functionality, of the network node 200 are omitted in order not to obscure the concepts presented herein.

Fig. 9 schematically illustrates, in terms of a number of functional modules, the components of a network node 200 according to an embodiment. The network node 200 of Fig. 9 comprises a number of functional modules; an obtain module 210a configured to perform step S102, a configure module 210b configured to perform step S104, and an initiate module 210g configured to perform step S106. The network node 200 of Fig. 9 may further comprise a number of optional functional modules, such as any of a select module 210c configured to perform step SiO4aa, a select module 2iod configured to perform step SiO4ab, a select module 2ioe configured to perform step SiO4ba, a select module 2iof configured to perform step SiO4bb, a provide module 2ioh configured to perform step Sio6a, and a provide module 2ioi configured to perform step Sio6b.

In general terms, each functional module 2ioa:2ioi may in one embodiment be implemented only in hardware and in another embodiment with the help of software, i.e., the latter embodiment having computer program instructions stored on the storage medium 230 which when run on the processing circuitry makes the network node 200 perform the corresponding steps mentioned above in conjunction with Fig 9. It should also be mentioned that even though the modules correspond to parts of a computer program, they do not need to be separate modules therein, but the way in which they are implemented in software is dependent on the programming language used. Preferably, one or more or all functional modules 210a: 2ioi may be implemented by the processing circuitry 210, possibly in cooperation with the communications interface 220 and/or the storage medium 230. The processing circuitry 210 may thus be configured to from the storage medium 230 fetch instructions as provided by a functional module 2ioa:2ioi and to execute these instructions, thereby performing any steps as disclosed herein.

The network node 200 may be provided as a standalone device or as a part of at least one further device. For example, the network node 200 may be provided in a node of the radio access network 110 or in a node of the core network 120. Alternatively, functionality of the network node 200 may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part (such as the radio access network 110 or the core network 120) or may be spread between at least two such network parts. In general terms, instructions that are required to be performed in real time may be performed in a device, or node, operatively closer to the cell than instructions that are not required to be performed in real time.

Thus, a first portion of the instructions performed by the network node 200 may be executed in a first device, and a second portion of the of the instructions performed by the network node 200 may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the network node 200 may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a network node 200 residing in a cloud computational environment. Therefore, although a single processing circuitry 210 is illustrated in Fig. 8 the processing circuitry 210 may be distributed among a plurality of devices, or nodes. The same applies to the functional modules 210a: 2ioi of Fig. 9 and the computer program 1020 of Fig. 10.

Fig. 10 shows one example of a computer program product 1010 comprising computer readable storage medium 1030. On this computer readable storage medium 1030, a computer program 1020 can be stored, which computer program 1020 can cause the processing circuitry 210 and thereto operatively coupled entities and devices, such as the communications interface 220 and the storage medium 230, to execute methods according to embodiments described herein. The computer program 1020 and/or computer program product 1010 may thus provide means for performing any steps as herein disclosed. In the example of Fig. io, the computer program product 1010 is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 1010 could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 1020 is here schematically shown as a track on the depicted optical disk, the computer program 1020 can be stored in any way which is suitable for the computer program product 1010.

Fig. 11 is a schematic diagram illustrating a telecommunication network connected via an intermediate network 420 to a host computer 430 in accordance with some embodiments. In accordance with an embodiment, a communication system includes telecommunication network 410, such as a 3GPP-type cellular network, which comprises access network 411, such as radio access network 110 in Fig. 2, and core network 414, such as core network 120 in Fig. 2. Access network 411 comprises a plurality of radio access network nodes 412a, 412b, 412c, such as NBs, eNBs, gNBs (each corresponding to the network node 200 of Fig. 2) or other types of wireless access points, each defining a corresponding coverage area, or cell, 413a, 413b, 413c. Each radio access network nodes 412a, 412b, 412c is connectable to core network 414 over a wired or wireless connection 415. A first UE 491 located in coverage area 413c is configured to wirelessly connect to, or be paged by, the corresponding network node 412c. A second UE 492 in coverage area 413a is wirelessly connectable to the corresponding network node 412a. While a plurality of UE 491, 492 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole terminal device is connecting to the corresponding network node 412. The UEs 491, 492 correspond to the user equipment 150a, 150b, 150c of Fig. 2.

Telecommunication network 410 is itself connected to host computer 430, which may be embodied in the hardware and/or software of a standalone server, a cloud- implemented server, a distributed server or as processing resources in a server farm. Host computer 430 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 421 and 422 between telecommunication network 410 and host computer 430 may extend directly from core network 414 to host computer 430 or may go via an optional intermediate network 420. Intermediate network 420 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 420, if any, may be a backbone network or the Internet; in particular, intermediate network 420 may comprise two or more sub-networks (not shown).

The communication system of Fig. 11 as a whole enables connectivity between the connected UEs 491, 492 and host computer 430. The connectivity may be described as an over-the-top (OTT) connection 450. Host computer 430 and the connected UEs 491, 492 are configured to communicate data and/or signalling via OTT connection 450, using access network 411, core network 414, any intermediate network 420 and possible further infrastructure (not shown) as intermediaries. OTT connection 450 may be transparent in the sense that the participating communication devices through which OTT connection 450 passes are unaware of routing of uplink and downlink communications. For example, network node 412 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 430 to be forwarded (e.g., handed over) to a connected UE 491. Similarly, network node 412 need not be aware of the future routing of an outgoing uplink communication originating from the UE 491 towards the host computer 430.

Fig. 12 is a schematic diagram illustrating host computer communicating via a radio access network node with a UE over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with an embodiment, of the UE, radio access network node and host computer discussed in the preceding paragraphs will now be described with reference to Fig. 12. In communication system 500, host computer 510 comprises hardware 515 including communication interface 516 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 500. Host computer 510 further comprises processing circuitry 518, which may have storage and/or processing capabilities. In particular, processing circuitry 518 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 510 further comprises software 511, which is stored in or accessible by host computer 510 and executable by processing circuitry 518. Software 511 includes host application 512. Host application 512 may be operable to provide a service to a remote user, such as UE 530 connecting via OTT connection 550 terminating at UE 530 and host computer 510. The UE 530 corresponds to the user equipment 150a, 150b, 150c of Fig. 2. In providing the service to the remote user, host application 512 may provide user data which is transmitted using OTT connection 550.

Communication system 500 further includes radio access network node 520 provided in a telecommunication system and comprising hardware 525 enabling it to communicate with host computer 510 and with UE 530. The radio access network node 520 corresponds to the network node 200 of Fig. 2. Hardware 525 may include communication interface 526 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 500, as well as radio interface 527 for setting up and maintaining at least wireless connection 570 with UE 530 located in a coverage area (not shown in Fig. 12) served by radio access network node 520. Communication interface 526 may be configured to facilitate connection 560 to host computer 510. Connection 560 may be direct or it may pass through a core network (not shown in Fig. 12) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 525 of radio access network node 520 further includes processing circuitry 528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Radio access network node 520 further has software 521 stored internally or accessible via an external connection.

Communication system 500 further includes UE 530 already referred to. Its hardware 535 may include radio interface 537 configured to set up and maintain wireless connection 570 with a radio access network node serving a coverage area in which UE 530 is currently located. Hardware 535 of UE 530 further includes processing circuitry 538, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 530 further comprises software 531, which is stored in or accessible by UE 530 and executable by processing circuitry 538. Software 531 includes client application 532. Client application 532 may be operable to provide a service to a human or non-human user via UE 530, with the support of host computer 510. In host computer 510, an executing host application 512 may communicate with the executing client application 532 via OTT connection 550 terminating at UE 530 and host computer 510. In providing the service to the user, client application 532 may receive request data from host application 512 and provide user data in response to the request data. OTT connection 550 may transfer both the request data and the user data. Client application 532 may interact with the user to generate the user data that it provides.

It is noted that host computer 510, radio access network node 520 and UE 530 illustrated in Fig. 12 may be similar or identical to host computer 430, one of network nodes 412a, 412b, 412c and one of UEs 491, 492 of Fig. 11, respectively. This is to say, the inner workings of these entities may be as shown in Fig. 12 and independently, the surrounding network topology may be that of Fig. 11.

In Fig. 12, OTT connection 550 has been drawn abstractly to illustrate the communication between host computer 510 and UE 530 via network node 520, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 530 or from the service provider operating host computer 510, or both. While OTT connection 550 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

Wireless connection 570 between UE 530 and radio access network node 520 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 530 using OTT connection 550, in which wireless connection 570 forms the last segment. More precisely, the teachings of these embodiments may reduce interference, due to improved classification ability of airborne UEs which can generate significant interference. A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 550 between host computer 510 and UE 530, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 550 may be implemented in software 511 and hardware 515 of host computer 510 or in software 531 and hardware 535 of UE 530, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 550 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 511, 531 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 550 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect network node 520, and it may be unknown or imperceptible to radio access network node 520. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signalling facilitating host computer’s 510 measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 511 and 531 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 550 while it monitors propagation times, errors etc.

The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

Claims

1. A method for transmission of New Radio, NR, control information in a Long Term Evolution, LTE, downlink subframe, wherein the NR control information is to be transmitted in NR Physical Downlink Control Channel, PDCCH, resource elements, REs, wherein the LTE downlink subframe comprises LTE Physical Control Format Indicator Channel, PCFICH, resource element groups, REGs, in which LTE control format information is to be transmitted, wherein the method is performed by a network node (200), and wherein the method comprises: obtaining (S102) information that neither LTE Physical channel Hybrid automatic repeat request Indicator Channel, PHICH, resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe, and in response thereto: configuring (S104) resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe, wherein which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not; and initiating (S106) transmission of the LTE downlink subframe.

2. The method according to claim 1, wherein, when all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the configuring further comprises: selecting (SiO4aa) at least one of the LTE PCFICH REGs for transmission of the LTE control format information whilst determining muting LTE transmission in at least one other of the LTE PCFICH REG; and selecting (SiO4ab) said at least one of the LTE PCFICH REGs for LTE transmission to be used for punctured transmission of the NR control information.

3. The method according to claim 1, wherein, when at least one of the LTE PCFICH REGs does not overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the configuring further comprises: selecting (SiO4ba) said at least one of the LTE PCFICH REGs for transmission of the LTE control format information whilst determining muting LTE transmission in at least one of the LTE PCFICH REGs and CRS that overlap with the NR PDCCH REs in the symbol at index o; selecting (SiO4bb) said at least one of the LTE PCFICH REGs where the LTE PCFICH REGs do not overlap with the NR PDCCH REs in the symbol at index o for transmission of the NR control information.

4. The method according to any preceding claim, wherein initiating the transmission of the LTE downlink subframe comprises: providing (Sio6a) information of the configured resource elements for the LTE transmission to a scheduler (242) of the LTE transmission; and providing (Sio6b) information of the configured resource elements for the NR transmission to a scheduler (244) of the NR transmission.

5. The method according to claim 4, wherein the information of the configured resource elements for the LTE transmission further indicates that power is to be transmitted only in the LTE PCFICH REGs selected for transmission of the LTE control format information and CRS which do not overlap with the NR PDCCH.

6. The method according to claim 4 or 5, wherein the information of the configured resource elements for the LTE transmission further indicates a power boost for the LTE PCFICH REGs selected for transmission of the LTE control format information.

7. The method according to any of claims 4 to 6, wherein, when any of the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the information of the configured resource elements for the NR transmission further indicates that a signal to interference plus noise ratio, SINR, level of the NR PDCCH REs is to be reduced.

8. The method according to any of claims 4 to 7, wherein the information of the configured resource elements for the NR transmission further indicates that punctured transmission of the NR control information involves muting transmission of the NR control information in the LTE PCFICH REGs selected for transmission of the LTE control format information after mapping the NR control information to physical-layer time/frequency resources.

9. The method according to any of claims 4 to 6, wherein, when at least one of the LTE PCFICH REGs does not overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe, the information of the configured resource elements for the NR transmission further indicates that power is to be transmitted only in said at least one of the LTE PCFICH REGs where the LTE PCFICH REGs and CRS do not overlap with the NR PDCCH REs in the symbol at index o for transmission of the NR control information.

10. The method according to any preceding claim, wherein the NR control information and the LTE control format information is to be transmitted on at least partly overlapping frequency carriers.

11. A network node (200) for transmission of New Radio, NR, control information in a Long Term Evolution, LTE, downlink subframe, wherein the NR control information is to be transmitted in NR Physical Downlink Control Channel, PDCCH, resource elements, REs, wherein the LTE downlink subframe comprises LTE Physical Control Format Indicator Channel, PCFICH, resource element groups, REGs, in which LTE control format information is to be transmitted, the network node (200) comprising processing circuitry (210), the processing circuitry being configured to cause the network node (200) to: obtain information that neither LTE Physical channel Hybrid automatic repeat request Indicator Channel, PHICH, resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe, and in response thereto: configure resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe, wherein which at least one of the LTE PCFICH REGs for LTE transmission that is selected to "2-1 be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not; and initiate transmission of the LTE downlink subframe.

12. A network node (200) for transmission of New Radio, NR, control information in a Long Term Evolution, LTE, downlink subframe, wherein the NR control information is to be transmitted in NR Physical Downlink Control Channel, PDCCH, resource elements, REs, wherein the LTE downlink subframe comprises LTE Physical Control Format Indicator Channel, PCFICH, resource element groups, REGs, in which LTE control format information is to be transmitted, the network node (200) comprising: an obtain module (210a) configured to obtain information that neither LTE Physical channel Hybrid automatic repeat request Indicator Channel, PHICH, resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe; a configure module (210b) configured to, in response thereto, configure resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe, wherein which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not; and an initiate module (210g) configured to initiate transmission of the LTE downlink subframe.

13. The network node (200) according to claim 11 or 12, further being configured to perform the method according to any of claims 2 to 10.

14. A computer program (1020) for transmission of New Radio, NR, control information in a Long Term Evolution, LTE, downlink subframe, wherein the NR control information is to be transmitted in NR Physical Downlink Control Channel, PDCCH, resource elements, REs, wherein the LTE downlink subframe comprises LTE Physical Control Format Indicator Channel, PCFICH, resource element groups, REGs, in which LTE control format information is to be transmitted, the computer program comprising computer code which, when run on processing circuitry (210) of a network node (200), causes the network node (200) to: obtain (S102) information that neither LTE Physical channel Hybrid automatic repeat request Indicator Channel, PHICH, resources nor LTE PDCCH resources for high priority traffic are needed in the LTE downlink subframe, and in response thereto: configure (S104) resource elements for transmission of the LTE control format information and resource elements for transmission of the NR control information overlapping with the LTE PCFICH REGs of the LTE downlink subframe, wherein which at least one of the LTE PCFICH REGs for LTE transmission that is selected to be used for transmission of the NR control information depends on whether all the LTE PCFICH REGs overlap with the NR PDCCH REs in the symbol at index o in the LTE downlink subframe or not; and initiate (S106) transmission of the LTE downlink subframe.

15. A computer program product (1010) comprising a computer program (1020) according to claim 14, and a computer readable storage medium (1030) on which the computer program is stored.