WO2021221403A1

WO2021221403A1 - A method and an apparatus for performing network aided power saving in nr ues in dss networks deploying tdm dss patterns

Info

Publication number: WO2021221403A1
Application number: PCT/KR2021/005222
Authority: WO
Inventors: Ajay Kumar MAHICHA; Sreenivas NALLURI; Vinayak BELLUR; Gaurav Mehta; Mohan Rao Naga Santha GOLI
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2020-04-27
Filing date: 2021-04-26
Publication date: 2021-11-04
Anticipated expiration: 2022-10-27

Abstract

The present invention generally relates to a wireless communication network, and more particularly, relates to Cellular Wireless Networks with Dynamic Shared Spectrum (DSS) feature enabled, and NR capable UEs. Specifically, to increase power save in 5G NR UEs, DSS networks that operate Time Division Multiplexed scheduling of LTE:NR downlink TTIs adopt an energy allocation strategy in the (RBs of) LTE guard bands. Such DSS networks indicate use of this strategy to 5G NR UEs that are in their coverage area, at the time of their respective initial attach procedures. 5G NR UEs in coverage of such DSS networks will be aware of the network strategy to allocate energy in (RBs of) LTE guard bands (only in the first symbol of every TTI). The 5G NR UEs avoid blind PDCCH decoding attempts in LTE operated downlink TTIs, and can turn off their NR receivers early.

Description

A METHOD AND AN APPARATUS FOR PERFORMING NETWORK AIDED POWER SAVING IN NR UES IN DSS NETWORKS DEPLOYING TDM DSS PATTERNS

The present invention generally relates to a wireless communication network, and more particularly, relates to Cellular Wireless Networks with Dynamic Shared Spectrum (DSS) feature enabled, and 5G NR capable UEs.

Dynamic Spectrum Sharing (DSS) is a technology that allows the deployment of both 4G LTE and 5G NR in the same frequency band and dynamically allocates spectrum resources between the two technologies based on user demand. As illustrated in Fig. 1, a spectrum of 10MHz is allocated to LTE and NR.

To accommodate 5G NR system within the current commercial LTE network deployment, or in the upcoming vRAN (LTE+NR) deployment spectrum sharing is an efficient solution. DSS is capable of assigning LTE and NR resources based on pre-defined resource sharing patterns. Resource sharing pattern is decided dynamically based on resource sharing policy (e.g. traffic status, load balancing etc.). As shown in Fig. 2a, state of the art solution for DSS, in DL, allows LTE and NR resource allocation based on TDM mode. Also, 1st symbol of every TTI is allocated to LTE. Since the resource sharing patterns are dynamically changed, there is no mechanism to indicate these patterns to UEs. Each UE will monitor the spectrum as single RAT deployment. During initial rollout, LTE sub frames are expected to be more than NR sub frames. This can lead to a significant power usage for NR UEs in LTE only sub frames. There lies at least a need to save NR UEs power in such scenario.

Figure. 2a illustrates spectrum sharing between LTE UE and NR UE as per the current state of the art. Fig. 2a illustrates an NR UE and LTE UE, both of the NR UE and the LTE UE are in the coverage area or connected to DSS enabled network operator (RU). However, the NR UE which is in the coverage area of the DSS enabled network operator is unaware of the allocation pattern of TDM LTE: NR used in Downlink (DL) scheduling. This is because there is no explicit signaling from the network to inform such UEs of the Time Division Multiplexed (TDM) LTE: NR Downlink Transmission Time Interval (TTI) distribution. If NR UEs cannot differentiate "NR only" TTI from "LTE only" TTI, when such a DSS pattern with TDM LTE: NR DL TTI distribution is being transmitted, then in every LTE only TTI, the NR UEs will expend power to do blind decoding attempts for PDCCH detection, and only after it fails, they will know that there is no NR traffic in that TTI. Extra power would have been expended to determine this.

5G NR UEs in coverage area of DSS network operator, are unaware of TDM LTE:NR allocation pattern used in Downlink (DL) scheduling. This is because there is no explicit signaling from the network to inform such UEs of the DL TTIs in the scheduling pattern operated for 5G NR traffic. If such 5G NR UEs cannot differentiate NR only TTI from LTE only TTI when a DSS pattern with TDM LTE:NR DL TTI distribution is being received, then in every LTE only TTI they will expend power to do blind decoding attempts for PDCCH detection, and only after it fails, they will know that there is no NR traffic in that TTI. In LTE operated TTIs, extra power would have been expended to run the blind decoding attempts on NR PDCCH region where there will be no NR information.

Figure 2b illustrates a state of the art vRAN Deployment Scenario. As shown in Fig 2b, state of the art DSS use vRAN for NR only. Figure 2c illustrates a future vRAN Deployment Scenario wherein DSS is expected to use vRAN both for NR and LTE.

State of the art publication US20170257774A1 focuses on spectrum sharing by allocating a chunk of frequencies of NR to operate as LTE SCell. Allocation pattern is in terms of Frequency division. NR Control plane is never allocated to LTE. Hence NR PDCCH region is not shared with LTE. Another state of the art publication US20190037579A1, focuses on FDM distribution of LTE and NR resources in a TTI. The same tries to define exclusive smaller Bandwidth parts for LTE and NR within the available bandwidth. RRC signaling is used to define and control the configuration of these bandwidth parts for LTE and NR.

Thus, as can be seen, there exists a need to overcome the aforementioned problem.

To meet the demand for wireless data traffic having increased since deployment of 4th generation (4G) communication systems, efforts have been made to develop an improved 5th generation (5G) or pre-5G communication system. The 5G or pre-5G communication system is also called a 'beyond 4G network' or a 'post long term evolution (LTE) system'. The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna techniques are discussed with respect to 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like. In the 5G system, hybrid frequency shift keying (FSK) and Feher's quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of everything (IoE), which is a combination of the IoT technology and the big data processing technology through connection with a cloud server, has emerged. As technology elements, such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "security technology" have been demanded for IoT implementation, a sensor network, a machine-to-machine (M2M) communication, machine type communication (MTC), and so forth have been recently researched. Such an IoT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analyzing data generated among connected things. IoT may be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combination between existing information technology (IT) and various industrial applications.

In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, MTC, and M2M communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud RAN as the above-described big data processing technology may also be considered to be as an example of convergence between the 5G technology and the IoT technology.

As described above, various services can be provided according to the development of a wireless communication system, and thus a method for easily providing such services is required.

This summary is provided to introduce a selection of concepts in a simplified format that is further described in the detailed description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

The present subject matter refers a method of power-efficient data transmission in a spectrum sharing based network environment. The method comprises sensing requirement of data transmission to a UE by a base-station, wherein such data transmission comprises a combination of LTE data packets and 5G data packets. Thereafter, a spectrum sharing based downlink (DL) transmission time interval (TTI) based scheduling pattern is generated for enabling said data transmission defined by said combination. Energy is incorporated in an LTE guard band in at-least one leading symbol of the LTE data packets for one or more of said DL TTI, said energy being detectable by a recipient UE. Further, the data comprising the combination of LTE data packets and 5G data packet is transmitted in accordance with the one or more DL TTIs having the energy in the LTE guard band.

In accordance with the present subject matter, a 5G NR UE in coverage area of DSS network operator may improve its power saving when it can determine which DL TTI is operated in NR mode and which DL TTI is operated in LTE mode.

The present subject matter defines a mechanism for DSS network operating in TDM of LTE: NR TTI scheduling to help 5G NR UEs to easily detect an LTE operated TTI in the downlink TTI scheduling pattern, and in those LTE only DL TTIs. The 5G NR UEs will turn off their receivers early in the start of the LTE only TTI (as early as 1st symbol). This avoids unnecessary NR PDCCH blind decoding attempts in LTE operated TTIs. Power saving gain in 5G NR UEs is improved in proportion to number of LTE operated TTIs in the DSS network's downlink TTI pattern.

To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

Fig. 1 illustrates, the basic concept of Dynamic Spectrum Sharing (DSS);

Fig. 2a, 2b, and 2c illustrate, exemplary scenarios of state of the art and future wireless communication system deploying DSS;

Fig. 3 illustrates a method of power-efficient data transmission in a spectrum-sharing based network environment;

Fig. 4 illustrates setup and signalling in respect of spectrum-sharing based network environment, in accordance with an embodiment of the present subject matter;

Fig. 5 illustrates a schematic representation of operation of a control logic at 5G NR UE receiver side to save power in LTE operated TTIs;

Fig. 6 illustrates, an exemplary scenario of Time Division Multiplexed scheduling of LTE:NR=7:3 Downlink TTI pattern; and

Fig. 7 illustrates an exemplary TTI view of 5G NR UE's Power Save Occasions.

Fig. 8 illustrates a hardware configuration of the network nodes and UE in the form of a computer-system.

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the invention and are not intended to be restrictive thereof.

Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

The present invention provides a method and system by which NR UEs in coverage of the DSS network sending out a TDM LTE: NR DL TTI pattern can distinguish LTE only DL TTIs from NR only DL TTIs, then in LTE only TTIs, the NR UEs can turn off the baseband receiver and NR radio early, and can save power by avoiding blind decoding attempts of PDCCH region.

Specifically, to increase power save in 5G NR UEs, DSS networks that operate Time Division Multiplexed scheduling of LTE:NR downlink TTIs adopt an energy allocation strategy in the (RBs of) LTE guard bands. This energy allocation strategy is only meant for the first symbol of every downlink TTI scheduled by such DSS networks, as the first symbol is an "LTE symbol". Such DSS networks indicate use of this strategy to 5G NR UEs that are in their coverage area, at the time of their respective initial attach procedures.

5G NR UEs in coverage of such DSS networks will be aware of the network strategy to allocate energy in (RBs of) LTE guard bands (only in the first symbol of every TTI), at the time of their initial attach to such DSS networks. By processing this information from network, 5G NR UEs, when in connected mode of operation, avoid blind PDCCH decoding attempts in LTE operated downlink TTIs, and can turn off their NR receivers early, thus saving more power.

More particularly, the present disclosure provides a solution in which:

1. DSS network which configures a certain Downlink TDM allocation pattern of LTE: NR in its coverage area, will allocate energy in the first OFDM symbol of Downlink TTIs allocated to LTE only, only in the unused RBs (e.g., RB#0 and RB#51), as these RBs are in the LTE guard band.

2. To inform the UEs in its coverage of this mechanism, at the time of initial access attempt from UE, DSS network will ensure that via existing DCI format signaling in Random Access Response to UE, it indicates by setting a reserved bit to '1' that will aid power save optimization for NR UEs.

3. An NR UE in the coverage of this DSS network, at the time of attaching to the NR Cell, will monitor the state of the reserved bit in the DCI format of Random Access Response from the network and only if set to '1' will check for power allocation in unused RBs (e.g., RB#0 and RB#51), of only first OFDM symbol of DL TTIs. With the help of this information, it will avoid blind PDCCH decoding attempts in "LTE only" DL TTIs, and be able to shut off power to baseband receiver early and save much more power.

The method and system of the present invention have the following advantages:

1. When an NR UE is in coverage of a DSS network operator that deploys TDM LTE: NR TTI scheduling, the NR UE can avoid PDCCH blind decoding attempts in LTE only TTIs. This results in good power save gain in the NR receivers, as the data path processing elements are not enabled for attempting to decode NR PDCCH in LTE operated TTIs.

2. DSS network operator that deploys TDM LTE: NR TTI scheduling can aid power saving in NR UEs in its coverage area by a simple one-time signaling method to UE during initial access/attach of the NR UE, using the existing capacity of DCI_1_0 format. No new Information elements need to be added to any signaling messages to convey this information.

3. No impact on UL Scheduling or UL processing on UEs that have an implementation of this idea.

4. Greater the ratio of LTE: NR in DL TTIs in the DSS allocation pattern scheduled by the network, the greater is the power optimization in NR UE.

5. When both network operator's TDM DSS solution and the UEs modem solution adopt this idea, high power saving gain can be achieved by in coverage NR UEs, when LTE: NR ratio has a higher proportion of LTE TTIs.

The aforementioned solutions are explained in more detail below, in a non-limiting manner.

In an exemplary embodiment of the present invention, 5G gNodeB while constructing DCI_Format_1_0 for Random Access (RA) Response resource allocation and operating in DSS mode uses one bit (least significant bits) from the 16 bits available (when UE is addressed with RA-RNTI) in the reserved bits and set it to '1' when triggering the network aided power save optimization in NR UE that attaches to it.

In the above exemplary embodiment, it may be considered that the NR guard bands are symmetrically positioned such that RB#0 and RB#51 of the NR 10MHz operation bandwidth, are in the LTE guard band.

In case where the guard band is asymmetrically positioned in the NR 10MHz operation bandwidth, (RB#0 and RB#1 or RB#50 and RB#51), then the network side may be adapted to use an additional least significant one bit in the reserved bits (16 bits) capacity of the DCI_Format_1_0 for Random Access Response, to signal the 5G NR UEs about the location of the RBs in LTE guard bands having energy. In such a scenario, the 5G NR UEs may simply need to read the combination of these two least significant bits in the DCI_Format_1_0 of the network Random Access Response and monitor those LTE guard band RBs that are allocated energy only, for fulfilling the power save optimization.

Figure. 3 illustrates a method of power-efficient data transmission in a spectrum-sharing based network environment.

The method comprises sensing (step 102) requirement of data transmission to a UE by a base-station, said data transmission comprising a combination of LTE data packets and 5G data packets. In an embodiment, the transmission of the LTE data packet and the 5G data packet comprises transmitting in the form of multiple DL TTIs defined by multiple LTE sub-frames and multiple NR subframes respectively.

Further, the method comprises generating (step 104) a spectrum sharing based downlink (DL) transmission time interval (TTI) based scheduling pattern for enabling said data transmission defined by said combination.

Further, the method comprises implementing (step 106) energy in an LTE guard band in at-least one leading symbol of the LTE data packets for one or more of said DL TTI, said energy being detectable by a recipient UE. In an example, the implementation of the energy comprises implementing the energy in the first symbol of each subframe corresponding to the multiple LTE data packets. The implementing of the energy comprises determining unused resource blocks (RBs) in the LTE guard band within the first symbol of DL TTIs, said first symbol being an LTE symbol with respect to a DSS downlink TTI scheduling pattern and said DL TTIs being LTE operated TTIs. The unused RBs in LTE guard band are appropriated in the first symbol of every TTI to include energy. Thereafter, power is allocated within the unused RBs at resource element (EPRE) level corresponding to the reference symbol energy in the first symbol and thereby signalling information to the recipient UE if the TTI is an LTE operated TTI.

Further, the method comprises transmitting (step 108) the data comprising the combination of LTE data packets and 5G data packet in accordance with the one or more DL TTIs having the energy in the LTE guard band. In an embodiment, the transmission of the LTE data packet and the 5G data packet comprises transmitting in the form of multiple DL TTIs defined by multiple LTE sub-frames and multiple NR subframes respectively.

Further, the method comprises triggering switching OFF of a 5G RAT by the UE upon detection of the energy by the recipient UE.

In an embodiment, the recipient UE may be configured for operating in a coverage area of a DSS deployment. Upon a successful access into an NR Cell, the UE is configured for detecting a Random Access Response (RAR) from the NR Cell having the reserved bit set in a DCI format. Energy-detection is monitored during the first symbol of the DL TTIs in unused RBs of LTE guard band. The TTIs are ascertained as LTE operated TTI or NR operated TTI based on the energy detection. Switching OFF of NR baseband receiver elements is triggered and NR PDCCH decoding attempts are not pursued in respect of the LTE operated TTIs. Thereafter, the switching ON of the NR baseband receiver elements is triggered in respect of the NR operated TTIs for initiating NR PDCCH decoding attempts.

Figure. 4 illustrates setup and signalling in respect of spectrum-sharing based network environment, in accordance with an embodiment of the present subject matter.

The present figure illustrates a vRAN 5G NR system within the a state of the art LTE network deployment, or an upcoming vRAN (LTE+NR) deployment DSS network operating Time Division Multiplexed LTE:NR DL TTIs. An EN-DC UE and DSS network have an established LTE Bearer. In operation, the set up and signalling comprises the following steps of operation as follows:

Step 402 refers establishment of EN-DC bearer. A 4G eNB sends an RRC Connection Reconfiguration to the UE to assign 5G NR radio resources to the UE.

Step 404 refers to UE successfully processing the RRC Connection Reconfiguration message, and sending the RRC Connection Reconfiguration Complete message to 4G eNB.

At step 406, the UE gains initial network access.

At step 408, with the NR Configuration Parameters, the UE attempts to connect to 5G gNB. It achieves 5G NR Downlink Time Synchronization, and then attempts initial access to 5G gNB (RACH procedure).

At step 410, in response to the UE NR RACH preamble (Msg1), 5G gNB, signals downlink resource allocation for RA response. DCI_Format_1_0 is used with RA-RNTI in this signal. At network side, while constructing DCI_Format_1_0 for RA Response resource allocation (i.e. Msg 2), 5G gNB should be able to use bits (least significant bits) from the 16 bits available (when UE is addressed with RA-RNTI) in the reserved bits and set it to '1', if it wants to trigger the network aided power save optimization in NR UE that attaches to it.

At step 412, UE is able to process the content of reserved bits in DCI_Format_1_0 (addressed by RA_RNTI), and if set, interpret it as an implicit signal to start its NR receiver ON duration evaluation, once UE moves to EN-DC Connected mode.

Thereafter, steps 414 and 416 as shown in Fig. 4 correspond to the following description of Fig. 5, 6 and Fig. 7.

Figure 5 illustrates a schematic representation of operation of a control logic at 5G NR UE receiver side to save power in LTE operated TTIs in accordance with an embodiment of the present subject matter. The control logic flow illustrated in the flow diagram is activated at NR UE side, once the Setup & Signalling as depicted in Fig. 4 a has been successfully completed.

Further, in accordance with the instant invention, an NR UE is present in the coverage area of a DSS deployment.

At step 502, after its successful Initial Access onto NR Cell and if Random Access Response (RAR) response from the NR Cell sets the reserved bit in DCI_0_1 format, begins to monitor for energy detection during the first symbol of downlink TTIs, specifically, in RB#0 and RB#51 of the first symbol.

Step 504 corresponds to a FFT pre-processing as a part of monitoring detection.

Step 506 corresponds to determining that the first symbol of every TTI is always an LTE symbol, and RB#0 and RB#51 in this first symbol is expected to be unused. When the energy detection procedure is executed in the first symbol as part of FFT pre-processing step in the UE receiver, energy is detected in REs of RB#0, and RB#51. The UE concludes that the current TTI is an LTE TTI, and NR baseband receiver elements are triggered to the power-off state. Thus, the NR receiver OFF state can be triggered early in every LTE TTI of the radio frame.

At step 508, during the FFT pre-processing in this first symbol itself, if UE is able to detect energy in RB#0 and RB#51, then it means the network has indicated to the UE that this particular TTI is for LTE.

At step 510, the receiver is triggered OFF in case the result of step 508 is YES.

Since the decision to turn off the power of NR receiver is made early in the FFT pre-processing, there is no need to engage the baseband processor's data path elements, and they can be turned off early in symbol 0 itself, avoiding the processing load of blind decoding attempts to detect and decode NR PDCCH CORESET. Avoiding NR PDCCH blind decoding attempts at-least save more power. Higher the LTE TTIs allocated in the DSS Downlink TTI pattern, greater is the magnitude of power save at UE. Furthermore, there is no negative impact on the LTE baseband receiver processing, and no additional processing required for the LTE receiver.

However, if the results of step 508 is NO, then it is determined that TTI is meant for NR. Accordingly, then control transfers to step 512 to perform decoding operation.

Figure. 6 illustrates example DSS TDM LTE:NR DL TTI allocation pattern and thereby depicts DSS network configuration which operates TDM allocation of LTE:NR Downlink TTI scheduling. More specifically, the present figure illustrates an example FDD frame type with TDM allocation LTE: NR = 7:3 with maximum NR TTI allocation = 3. In

Downlink TTIs

1,3,4,5,7,8,9 LTE traffic is scheduled. In reference to Fig 6. and by way of a non-limiting example, it is explained that how power is saved in NR UE in the DSS network coverage.

In accordance with an example operation, DSS network allocates a spectrum of 10 MHz to LTE and NR. DSS network has scheduled 7 LTE TTIs, and 3 NR TTIs in the downlink. This is a repetitive DL pattern scheduled by the DSS network every radio frame.

Downlink TTIs

1,2,6 are NR operated TTIs, and

downlink TTIs

0,3,4,5,7,8,9 are LTE operated TTIs. NR PDCCH CORESET allocation configuration is executed in time domain based on 3 OFDM symbols (not shown in picture).

Further, RB#0 and RB#51 are the unused RBs in the LTE guard band, in LTE operated Downlink TTIs. Symbol 0 of every downlink TTI is an 'LTE symbol'. RB#0 and RB#51 in LTE guard band in first symbol of every TTI are used to signal information to NR UE to indicate if the TTI is an LTE operated TTI. On the 5G NR UE side, the signalling at setup procedure in accordance with Fig. 4 has already been done, and both network and UE execute the operation in accordance with the steps 102 to 106 and in accordance with description of Fig. 5. More specifically, the NR UE in coverage of this network synchronizes with the NR Cell during the successful initial access to the NR Cell, gets information from network RAR response, DCI_Format_1_0 that its power save optimization will be aided by the network.

Figure. 7 illustrates a TTI view of 5G NR UE Power Save Occasions in accordance with an embodiment of the present subject matter. More specifically, the present figure illustrates how an NR UE attached to the DSS network, which is scheduling TDM LTE:NR 7:3 allocation pattern, can find occasions to turn OFF its receiver early during the first symbol of an LTE operated TTI.

As shown in Fig. 7, first symbol of every TTI in this pattern carries LTE PDCCH, so from frequency domain point of view the first symbol of every TTI will have unused RBs ( RB#0 and RB#51), in the LTE guard band, that carry no power. During LTE operated TTIs, in the first symbol (symbol 0) of the TTI, the unused RBs (RB#0, and RB#51) which are part of the LTE guard band have their power boosted by DSS network to indicate absence of NR operation in this TTI. In these LTE only TTIs, NR receiver chain is turned off early, and no blind NR PDCCH decoding attempt is made in NR UEs, as shown in figure below.

During NR operated TTIs, in the first symbol (symbol#0) of the TTI, the unused RBs (RB#0, and RB#51) which are part of the LTE guard band have no power allocated, and NR UEs with this, NR UEs will know that this particular TTI is operated by network to schedule NR traffic. For every new DL TTI, at UE, such evaluation for power allocation in first OFDM symbol is repeated.

At least based on the preceding description, the UE receiver in connected mode 5G NR detects energy in the first symbol of downlink (LTE)

TTIs

1,3,4,5,7,8,9, in their unused RBs (RB#0, and RB#51). By way of this early energy detection in RB#0 and RB#51 of the first symbol of the

TTIs

1,3,4,5,7,8,9, UE concludes that those TTIs are LTE TTIs. Therefore in all the LTE TTIs of the DSS DL pattern in a radio frame, the NR baseband receiver elements are triggered to OFF state after the first symbol. The present subject matter at least avoids blind (NR) PDCCH decoding attempts in every LTE TTI and thereby saves more power compared to the state of the art scenario.

In the current example of PDCCH CORESET configuration, NR receiver can be kept off for an additional 3 OFDM symbols per LTE TTI, compared to the case without this idea. Cumulatively in this example, the NR receiver can be kept off for an additional 21 OFDM symbols per System Frame duration (10 ms), compared to the case without this idea. The NR receiver on the UE can be kept OFF for an additional 2100 OFDM symbols per second, compared to the case without this idea. In UE RRC connected mode, power gain in the UE will increase as the proportion of allocation of LTE TTIs in the DSS pattern configured from the network becomes more, as there are proportionally more NR PDCCH symbols on which blind decoding attempts from NR receiver can be avoided.

Figure 8 shows an example implementation in accordance with the embodiment of the invention, and yet another typical hardware configuration of the network nodes and UE in preceding figures in the form of a computer-system and architecture 1100. The computer system 1100 can include a set of instructions that can be executed to cause the computer system 1100 to perform any one or more of the methods disclosed. The computer system 1100 may operate as a standalone-device or may be connected, e.g., using a network, to other computer systems or peripheral devices.

In a networked deployment, the computer system 1100 may operate in the capacity of a server or as a client user computer in a server-client user network environment, or as a peer computer system in a peer-to-peer (or distributed) network environment. The computer system 1100 can also be implemented as or incorporated across various devices, such as a personal computer (PC), a tablet PC, a personal digital assistant (PDA), a mobile device, a palmtop computer, a laptop computer, a desktop computer, a communications device, a wireless telephone, a land-line telephone, a web appliance, a network router, switch or bridge, or any other machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while a single computer system 1100 is illustrated, the term "system" shall also be taken to include any collection of systems or sub-systems that individually or jointly execute a set, or multiple sets, of instructions to perform one or more computer functions.

The computer system 1100 may include a processor 1102 e.g., a central processing unit (CPU), a graphics processing unit (GPU), or both. The processor 1102 may be a component in a variety of systems. For example, the processor 1102 may be part of a standard personal computer or a workstation. The processor 1102 may be one or more general processors, digital signal processors, application specific integrated circuits, field programmable gate arrays, servers, networks, digital circuits, analog circuits, combinations thereof, or other now known or later developed devices for analysing and processing data. The processor 1102 may implement a software program, such as code generated manually (i.e., programmed).

The computer system 1100 may include a memory 1104, such as a memory 1104 that can communicate via a bus 1108. The memory 1104 may include, but is not limited to computer readable storage media such as various types of volatile and non-volatile storage media, including but not limited to random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, magnetic tape or disk, optical media and the like. In one example, the memory 1104 includes a cache or random access memory for the processor 1102. In alternative examples, the memory 1104 is separate from the processor 1102, such as a cache memory of a processor, the system memory, or other memory. The memory 1104 may be an external storage device or database for storing data. The memory 1104 is operable to store instructions executable by the processor 1102. The functions, acts or tasks illustrated in the figures or described may be performed by the programmed processor 1102 for executing the instructions stored in the memory 1104. The functions, acts or tasks are independent of the particular type of instructions set, storage media, processor or processing strategy and may be performed by software, hardware, integrated circuits, firm-ware, micro-code and the like, operating alone or in combination. Likewise, processing strategies may include multiprocessing, multitasking, parallel processing and the like.

As shown, the computer system 1100 may or may not further include a display unit 1110, such as a liquid crystal display (LCD), an organic light emitting diode (OLED), a flat panel display, a solid state display, a cathode ray tube (CRT), a projector, a printer or other now known or later developed display device for outputting determined information. The display 1110 may act as an interface for the user to see the functioning of the processor 1102, or specifically as an interface with the software stored in the memory 1104 or in the drive unit 1016.

Additionally, the computer system 1100 may include an input device 1112 configured to allow a user to interact with any of the components of system 1100. The computer system 1100 may also include a disk or optical drive unit 1116. The disk drive unit 1116 may include a computer-readable medium 1122 in which one or more sets of instructions 1124, e.g. software, can be embedded. Further, the instructions 1124 may embody one or more of the methods or logic as described. In a particular example, the instructions 1124 may reside completely, or at least partially, within the memory 1104 or within the processor 1102 during execution by the computer system 1100.

The present invention contemplates a computer-readable medium that includes instructions 1124 or receives and executes instructions 1124 responsive to a propagated signal so that a device connected to a network 1126 can communicate voice, video, audio, images or any other data over the network 1126. Further, the instructions 1124 may be transmitted or received over the network 1126 via a communication port or interface 1120 or using a bus 1108. The communication port or interface 1120 may be a part of the processor 1102 or may be a separate component. The communication port 1120 may be created in software or may be a physical connection in hardware. The communication port 1120 may be configured to connect with a network 1126, external media, the display 1110, or any other components in system 1100, or combinations thereof. The connection with the network 1126 may be a physical connection, such as a wired Ethernet connection or may be established wirelessly as discussed later. Likewise, the additional connections with other components of the system 1100 may be physical connections or may be established wirelessly. The network 1126 may alternatively be directly connected to the bus 1108.

The network 1126 may include wired networks, wireless networks, Ethernet AVB networks, or combinations thereof. The wireless network may be a cellular telephone network, an 802.11, 802.16, 802.20, 802.1Q or WiMax network. Further, the network 1126 may be a public network, such as the Internet, a private network, such as an intranet, or combinations thereof, and may utilize a variety of networking protocols now available or later developed including, but not limited to TCP/IP based networking protocols. The system is not limited to operation with any particular standards and protocols. For example, standards for Internet and other packet switched network transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP) may be used.

While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein.

Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to the problem and any component(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or component of any or all the claims.

Claims

A method of power-efficient data transmission in a spectrum sharing based network environment, said method comprising:

sensing (102) requirement of data transmission to a UE by a base-station, said data transmission comprising a combination of LTE data packets and 5G data packets;

generating (104) a spectrum sharing based downlink (DL) transmission time interval (TTI) based scheduling pattern for enabling said data transmission defined by said combination;

implementing energy (106) in an LTE guard band in at-least one leading symbol of the LTE data packets for one or more of said DL TTI, said energy being detectable by a recipient UE; and

transmitting (108) the data comprising the combination of LTE data packets and 5G data packet in accordance with the one or more DL TTIs having the energy in the LTE guard band.
The method as claimed in claim 1, wherein the transmission of the LTE data packet and the 5G data packet comprises transmitting in the form of multiple DL TTIs defined by multiple LTE sub-frames and multiple NR subframes respectively.
The method as claimed in claim 2, wherein the implementation of the energy comprises implementing the energy in the first symbol of each subframe corresponding to the multiple LTE data packets.
The method as claimed in claim 1, wherein the implementing of the energy comprises:

determining unused resource blocks (RBs) in the LTE guard band within the first symbol of DL TTIs, said first symbol being an LTE symbol with respect to a DSS downlink TTI scheduling pattern and said DL TTIs being LTE operated TTIs;

appropriating the unused RBs in LTE guard band in the first symbol of every TTI to include energy;

allocating power within the unused RBs at resource element (EPRE) level corresponding to the reference symbol energy in the first symbol and thereby signalling information to the recipient UE if the TTI is an LTE operated TTI.
The method as claimed in claim 4, further comprising maintaining the unused RBs without power allocation in respect of DL TTIs corresponding to the NR operated TTIs.
The method as claimed in claim 1, further comprising:

triggering switching OFF of a 5G RAT by the UE upon detection of the energy by the recipient UE.
The method as claimed in claim 6, wherein the recipient UE is configured for operating in a coverage area of a DSS deployment and upon a successful access into an NR Cell executes the steps of:

detecting a Random Access Response (RAR) from the NR Cell having the reserved bit set in a DCI format;

monitoring energy-detection during the first symbol of the DL TTIs in unused RBs of LTE guard band;

ascertaining the TTIs as LTE operated TTI or NR operated TTI based on the energy detection;

triggering switching OFF of NR baseband receiver elements and refraining from NR PDCCH decoding attempts in respect of the LTE operated TTIs; and

triggering switching ON of the NR baseband receiver elements in respect of the NR operated TTIs and thereby initiating NR PDCCH decoding attempts.
A network node (gNB, eNB) for power-efficient data transmission in a spectrum sharing based network environment (DSS), said network node (gNB, eNB) comprising:

a processor (1102) for

sensing requirement of data transmission to a UE, said data transmission comprising a combination of LTE data packets and 5G data packets;

generating a spectrum sharing based downlink (DL) transmission time interval (TTI) based scheduling pattern for enabling said data transmission defined by said combination;

implementing energy in an LTE guard band in at-least one leading symbol of the LTE data packets for one or more of said DL TTI, said energy being detectable by a recipient UE; and

a transceiver (1120) for transmitting the data comprising the combination of LTE data packets and 5G data packet in accordance with the one or more DL TTIs having the energy in the LTE guard band.
The node(gNB, eNB) as claimed in claim 8, wherein the transmission of the LTE data packet and the 5G data packet comprises transmitting in the form of multiple DL TTIs defined by multiple LTE sub-frames and multiple NR subframes respectively.
The node(gNB, eNB) as claimed in claim 9, wherein the implementation of the energy by the processor comprises implementing the energy in the first symbol of each subframe corresponding to the multiple LTE data packets.
The node (gNB, eNB) as claimed in claim 8, wherein the implementing of the energy by the processor comprises:

determining unused resource blocks (RBs) in the LTE guard band within the first symbol of DL TTIs, said first symbol being an LTE symbol with respect to a DSS downlink TTI scheduling pattern and said DL TTIs being LTE operated TTIs;

appropriating the unused RBs in LTE guard band in the first symbol of every TTI to include energy;

allocating power within the unused RBs at resource element (EPRE) level corresponding to the reference symbol energy in the first symbol and thereby signalling information to the recipient UE if the TTI is an LTE operated TTI.
The node (gNB, eNB) as claimed in claim 11, wherein the processor is further configured for maintaining the unused RBs without power allocation in respect of DL TTIs corresponding to the NR operated TTIs.
The node(gNB, eNB) as claimed in claim 8, wherein a UE communicatively linked to the networking node is configured for:

triggering switching OFF of a 5G RAT by the UE upon detection of the energy by the recipient UE.
The node (gNB, eNB) as claimed in claim 13, wherein the UE is configured for operating in a coverage area of a DSS deployment and upon a successful access into an NR Cell executes the steps of:

detecting a Random Access Response (RAR) from the NR Cell having the reserved bit set in a DCI format;

monitoring energy-detection during the first symbol of the DL TTIs in unused RBs of LTE guard band;

ascertaining the TTIs as LTE operated TTI or NR operated TTI based on the energy detection;

triggering switching OFF of NR baseband receiver elements and refraining from NR PDCCH decoding attempts in respect of the LTE operated TTIs; and

triggering switching ON of the NR baseband receiver elements in respect of the NR operated TTIs and thereby initiating NR PDCCH decoding attempts.