Patent Publication Number: US-2023142795-A1

Title: Method and terminal device for measurement control

Description:
TECHNICAL FIELD 
     Embodiments of the disclosure generally relate to wireless communication, and, more particularly, to a method and a terminal device for measurement control. 
     BACKGROUND 
     This section introduces aspects that may facilitate better understanding of the present disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art. 
     From analog through long term evolution (LTE), each generation of mobile technology has been motivated by the need to address the challenges not overcome by its predecessor. The 5th generation (5G) of mobile technology is positioned to address the demands and business beyond LTE. It is expected to enable a fully mobile and connected society, related to the tremendous growth in connectivity and density/volume of traffic that will be required in the near future. 
     China Telecom and China Unicom have reached a tentative agreement to jointly build a 5G network and share network infrastructure. It is possible that China Mobile may join them. The three Chinese operators co-own a tower company, China Tower Corp, which would make it easier for them to collaborate on building out all the thousands of base stations necessary for a new 5G network in China. 
     Generally speaking, there are various forms of network sharing, including: mast/site sharing where mobile operators use the same tower sites to co-locate equipments, but otherwise everything else is separate; radio access network (RAN) sharing where operators share all the equipments in the network as far back as the base station controller/radio network controller; and network roaming where competing operators agree to host one another&#39;s customers on their networks in certain geographic areas. The above first and third items are mainly impacted by business negotiation, while the second one may be implemented in different manners. 
       FIG.  1    shows two exemplary sharing scenarios for the above second item. The multi-operator core network (MOCN) defines that individual core networks are possessed by different operators, while the hardware (HW), software (SW), radio resource at radio and base band are totally shared in the manner of a predefined percentage. Multi-operator RAN (MORAN) defines that core networks and cells are separated for different operators, while radio and base band are partially or completely shared in the manner of a predefined percentage. 
     Furthermore, for the initial stage of 5G new radio (NR) deployment, one of most typical configuration for NR is to share spectrum resources or partially share spectrum resources with 4th generation (4G) network with the help of mix mode radio. With more and more user equipments (UEs) phasing out from 4G network and more and more UEs emerging in 5G network, spectrum resources will gradually shift from 4G to 5G, which can flexibly balance near term and long term network requirements. For example, the table below shows a configuration that China Mobile Communications Group Co., Ltd (CMCC) suggested for 2020 NR rollout. In this configuration, there will be 40 MHz spectrum shared with LTE. 
     
       
         
           
               
               
            
               
                   
                   
               
               
                   
                 MHz 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 2515- 
                 2535- 
                 2555- 
                 2575- 
                 2595- 
                 2615- 
               
               
                   
                 2535 
                 2555 
                 2575 
                 2595 
                 2615 
                 2635 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                 CMCC 
                 NR only 
                 LTE/NR 
                 LTE only 
               
               
                 bands 
                   
                 sharing 
               
               
                   
               
            
           
         
       
     
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. 
     One of the objects of the disclosure is to provide an improved solution for measurement control. 
     According to a first aspect of the disclosure, there is provided a method performed by a terminal device. The method may comprise detecting, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. The method may further comprise, when detecting that frequency bands used by the two operators for the cell are overlapped, performing measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The method may further comprise reporting information about a result of the measurement to the two operators. 
     In this way, the power consumption at the terminal device can be reduced. 
     In an embodiment of the disclosure, the cell to be measured by the terminal device may be a cell serving the terminal device, or a neighboring cell of the cell serving the terminal device. 
     In an embodiment of the disclosure, the method may further comprise determining whether a same neighboring cell is to be measured for the two operators. The method may further comprise, when determining that a same neighboring cell is to be measured for the two operators, performing measurement on the same neighboring cell only one time. The method may further comprise reporting information indicating the same result of the measurement to the two operators. 
     In an embodiment of the disclosure, the two frequency bands may be the same with each other. The measurement may be performed at the same frequency band. The information sent to the two operators may indicate the same result of the measurement. 
     In an embodiment of the disclosure, the frequency bands may be a first frequency band used by a first operator and a second frequency band used by a second operator, and the overlapped portion of the frequency bands may be the second frequency band. The measurement may be performed at the first frequency band. The information sent to the second operator may indicate part of the result of the measurement corresponding to the second frequency band. 
     In an embodiment of the disclosure, the two frequency bands may be staggered from each other with a portion overlapped therebetween. The measurement may be performed at the overlapped portion. The information sent to the two operators may contain the same result of the measurement. 
     In an embodiment of the disclosure, discontinuous reception (DRX) periods of the two operators may be completely overlapped with each other. The measurement may be performed at one of measurement opportunities for the two operators, which is closest to the earliest one of reporting occasions for the two operators. 
     In an embodiment of the disclosure, the frequency bands may be a first frequency band used by a first operator and a second frequency band used by a second operator, and a second DRX period of the second operator may fall within a first DRX period of the first operator. The measurement may be performed at a measurement opportunity for the second operator, without using measurement opportunity for the first operator. 
     In an embodiment of the disclosure, DRX periods of the two operators may be staggered from each other with a portion overlapped therebetween. The measurement may be performed at a measurement opportunity for one of the two operators whose DRX period starts earlier. 
     In an embodiment of the disclosure, detecting whether the frequency bands are overlapped may comprise obtaining, from a server, information about radio and spectrum sharing. Detecting whether the frequency bands are overlapped may comprise determining whether the frequency bands are overlapped based on the obtained information. 
     In an embodiment of the disclosure, detecting whether the frequency bands are overlapped may comprise determining a first channel matrix of a first channel for a first operator, based on measurement on the reference signal carried by the first channel. Detecting whether the frequency bands are overlapped may comprise determining a second channel matrix of a second channel for a second operator, based on measurement on the reference signal carried by the second channel. Detecting whether the frequency bands are overlapped may comprise determining whether the two channels are the same channel based on the two channel matrixes. 
     In an embodiment of the disclosure, determining whether the two channels are the same channel based on the two channel matrixes may comprise calculating a product between the first channel matrix and a conjugate transpose matrix of the second channel matrix. Determining whether the two channels are the same channel based on the two channel matrixes may comprise calculating a ratio between a sum of powers of diagonal elements of the product and a sum of powers of all elements of the product. Determining whether the two channels are the same channel based on the two channel matrixes may comprise, when the ratio is above a predetermined threshold, determining that the two channels are the same channel. 
     In an embodiment of the disclosure, the reference signal may be a channel state information reference signal (CSI-RS) or a tracking reference signal (TRS). 
     In an embodiment of the disclosure, the method may further comprise providing user data and forwarding the user data to a host computer via the transmission to a base station. 
     According to a second aspect of the disclosure, there is provided a terminal device. The terminal device may comprise at least one processor and at least one memory. The at least one memory may contain instructions executable by the at least one processor, whereby the terminal device may be operative to detect, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. The terminal device may be further operative to, when detecting that frequency bands used by the two operators for the cell are overlapped, perform measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The terminal device may be further operative to report information about a result of the measurement to the two operators. 
     In an embodiment of the disclosure, the cell to be measured by the terminal device may be a cell serving the terminal device, or a neighboring cell of the cell serving the terminal device. 
     In an embodiment of the disclosure, the instructions may be executable by the at least one processor, whereby the terminal device may be further operative to determine whether a same neighboring cell is to be measured for the two operators. The terminal device may be further operative to, when determining that a same neighboring cell is to be measured for the two operators, perform measurement on the same neighboring cell only one time. The terminal device may be further operative to report information indicating the same result of the measurement to the two operators. 
     In an embodiment of the disclosure, the two frequency bands may be the same with each other. The measurement may be performed at the same frequency band. The information sent to the two operators may indicate the same result of the measurement. 
     In an embodiment of the disclosure, the frequency bands may be a first frequency band used by a first operator and a second frequency band used by a second operator, and the overlapped portion of the frequency bands may be the second frequency band. The measurement may be performed at the first frequency band. The information sent to the second operator may indicate part of the result of the measurement corresponding to the second frequency band. 
     In an embodiment of the disclosure, the two frequency bands may be staggered from each other with a portion overlapped therebetween. The measurement may be performed at the overlapped portion. The information sent to the two operators may contain the same result of the measurement. 
     In an embodiment of the disclosure, DRX periods of the two operators may be completely overlapped with each other. The measurement may be performed at one of measurement opportunities for the two operators, which is closest to the earliest one of reporting occasions for the two operators. 
     In an embodiment of the disclosure, the frequency bands may be a first frequency band used by a first operator and a second frequency band used by a second operator, and a second DRX period of the second operator may fall within a first DRX period of the first operator. The measurement may be performed at a measurement opportunity for the second operator, without using measurement opportunity for the first operator. 
     In an embodiment of the disclosure, DRX periods of the two operators may be staggered from each other with a portion overlapped therebetween. The measurement may be performed at a measurement opportunity for one of the two operators whose DRX period starts earlier. 
     In an embodiment of the disclosure, the instructions may be executable by the at least one processor, whereby the terminal device may be operative to detect whether the frequency bands are overlapped by obtaining, from a server, information about radio and spectrum sharing. The terminal device may be operative to detect whether the frequency bands are overlapped by determining whether the frequency bands are overlapped based on the obtained information. 
     In an embodiment of the disclosure, the instructions may be executable by the at least one processor, whereby the terminal device may be operative to detect whether the frequency bands are overlapped by determining a first channel matrix of a first channel for a first operator, based on measurement on the reference signal carried by the first channel. The terminal device may be operative to detect whether the frequency bands are overlapped by determining a second channel matrix of a second channel for a second operator, based on measurement on the reference signal carried by the second channel. The terminal device may be operative to detect whether the frequency bands are overlapped by determining whether the two channels are the same channel based on the two channel matrixes. 
     In an embodiment of the disclosure, the instructions may be executable by the at least one processor, whereby the terminal device may be operative to determine whether the two channels are the same channel based on the two channel matrixes by calculating a product between the first channel matrix and a conjugate transpose matrix of the second channel matrix. The terminal device may be operative to determine whether the two channels are the same channel based on the two channel matrixes by calculating a ratio between a sum of powers of diagonal elements of the product and a sum of powers of all elements of the product. The terminal device may be operative to determine whether the two channels are the same channel based on the two channel matrixes by, when the ratio is above a predetermined threshold, determining that the two channels are the same channel. 
     In an embodiment of the disclosure, the reference signal may be a CSI-RS or a TRS. 
     According to a third aspect of the disclosure, there is provided a computer program product. The computer program product may comprise instructions which when executed by at least one processor, cause the at least one processor to perform the method according to the above first aspect. 
     According to a fourth aspect of the disclosure, there is provided a computer readable storage medium. The computer readable storage medium may comprise instructions which when executed by at least one processor, cause the at least one processor to perform the method according to the above first aspect. 
     According to a fifth aspect of the disclosure, there is provided a terminal device. The terminal device may comprise a detection module for detecting, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. The terminal device may further comprise a measurement module for, when detecting that frequency bands used by the two operators for the cell are overlapped, performing measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The terminal device may further comprise a reporting module for reporting information about a result of the measurement to the two operators. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects, features and advantages of the disclosure will become apparent from the following detailed description of illustrative embodiments thereof, which are to be read in connection with the accompanying drawings. 
         FIG.  1    is a diagram illustrating exemplary RAN sharing scenarios; 
         FIG.  2    is a flowchart illustrating a method implemented at a terminal device according to an embodiment of the disclosure; 
         FIGS.  3 A- 3 B  are flowcharts for explaining the method of  FIG.  2   ; 
         FIG.  4    is a flowchart for explaining the method of  FIG.  3 B ; 
         FIG.  5    is a diagram illustrating different cases of frequency band overlapping; 
         FIG.  6    is a diagram illustrating different cases of DRX configurations; 
         FIG.  7    is a diagram for explaining the method of  FIG.  2   ; 
         FIG.  8    is a flowchart illustrating a method implemented at a terminal device according to another embodiment of the disclosure; 
         FIG.  9    is a block diagram showing an apparatus suitable for use in practicing some embodiments of the disclosure; 
         FIG.  10    is a block diagram showing a terminal device according to an embodiment of the disclosure; 
         FIG.  11    is a diagram showing a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments; 
         FIG.  12    is a diagram showing a host computer communicating via a base station with a user equipment in accordance with some embodiments; 
         FIG.  13    is a flowchart illustrating a method implemented in a communication system in accordance with some embodiments; 
         FIG.  14    is a flowchart illustrating a method implemented in a communication system in accordance with some embodiments; 
         FIG.  15    is a flowchart illustrating a method implemented in a communication system in accordance with some embodiments; and 
         FIG.  16    is a flowchart illustrating a method implemented in a communication system in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     For the purpose of explanation, details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed. It is apparent, however, to those skilled in the art that the embodiments may be implemented without these specific details or with an equivalent arrangement. 
     References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. Some of the embodiments described separately or independently hereafter may also be implemented in combination depending on various application scenarios. 
     As a cell is shared by multiple operators and a UE may be equipped with multiple subscriber identity module (SIM) cards and connected to those multiple operators, RAN views this UE as multiple individual UEs and individually configures measurements. Then, the UE must do double or even triple measurements for the same cell or even the same reference signals. This causes unnecessary power consumption at the UE which is quite critical for mobile users. 
     The present disclosure proposes an improved solution for measurement control. The solution may be applied to a communication system including a terminal device and an access network node. For example, the access network node may be a base station such as a next generation node base station (gNB) in NR. The terminal device can communicate through a radio access communication link with the base station. The base station can provide radio access communication links to terminal devices that are within its communication service cell. Note that the communications may be performed between the terminal device and the base station according to any suitable communication standards and protocols. 
     The terminal device may also be referred to as, for example, device, access terminal, user equipment (UE), mobile station, mobile unit, subscriber station, or the like. It may refer to any end device that can access a wireless communication network and receive services therefrom. By way of example and not limitation, the terminal device may include a portable computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback appliance, a mobile phone, a cellular phone, a smart phone, a tablet, a wearable device, a personal digital assistant (PDA), or the like. 
     In an Internet of things (IoT) scenario, a terminal device may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another terminal device and/or a network equipment. In this case, the terminal device may be a machine-to-machine (M2M) device, which may, in a 3GPP context, be referred to as a machine-type communication (MTC) device. Particular examples of such machines or devices may include sensors, metering devices such as power meters, industrial machineries, bikes, vehicles, or home or personal appliances, e.g. refrigerators, televisions, personal wearables such as watches, and so on. 
     Hereinafter, the solution will be described in detail with reference to  FIGS.  2 - 16   .  FIG.  2    is a flowchart illustrating a method implemented at a terminal device according to an embodiment of the disclosure. At block  202 , the terminal device detects, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands (or operating bands) used by the two operators for the cell are overlapped. In other words, the terminal device detects whether the cell is shared by different operators at the same or partially overlapped frequency band. Block  202  is performed in consideration of the fact that when the terminal device is equipped with the two operators&#39; SIM cards, it cannot explicitly know whether a cell is shared by the two operators in the mode of MOCN, dynamic spectrum sharing or even a mixed scenario, and it also cannot explicitly know whether the signals for different operators are coming from one radio. The cell to be measured by the terminal device may be a cell serving the terminal device, or a neighboring cell of the cell serving the terminal device. Note that it is possible for the cell to be shared by more than two operators. In this case, the “two operators” described in block  202  may refer to any two of the multiple operators. 
     As an option, block  202  may be implemented as blocks  308 - 310  of  FIG.  3 A . At block  308 , the terminal device obtains, from a server, information about radio and spectrum sharing. For example, such information (e.g. the base stations shared by multiple operators, the corresponding spectrums, etc.) may be available publicly through the server. The terminal device may obtain such information from the server through an application software, for example. At block  310 , the terminal device determines whether the frequency bands are overlapped based on the obtained information. This determination may be made since the terminal device can be explicitly aware of such deployment of radio and spectrum sharing. For example,  FIG.  5    illustrates different cases of frequency band overlapping. In case A, the two frequency bands are the same with each other. In case B, the overlapped portion of the frequency bands is the second frequency band. In case C, the two frequency bands are staggered from each other with a portion overlapped therebetween. 
     As another option, block  202  may be implemented as blocks  312 - 316  of  FIG.  3 B . At block  312 , the terminal device determines a first channel matrix (denoted as H 1 ) of a first channel for a first operator, based on measurement on a reference signal carried by the first channel. At block  314 , the terminal device determines a second channel matrix (denoted as H 2 ) of a second channel for a second operator, based on measurement on the reference signal carried by the second channel. For example, as the terminal device is connected to the two operators, it may be configured by radio resource control (RRC) (re)configurations and measurement configurations from the two operators, respectively. With the RRC (re)configuration, the terminal device may know the channel carrying the reference signal to be measured. The reference signal may be a channel state information reference signal (CSI-RS) or a tracking reference signal (TRS). At block  316 , the terminal device determines whether the two channels are the same channel based on the two channel matrixes. If the two channels are the same channel, it may be determined that frequency bands used by the two operators for the cell are overlapped. If the two channels are not the same channel, it means they are experiencing different fading. For example, blocks  312 - 316  may be performed periodically to evaluate the similarity between the channels. 
     As an exemplary example, block  316  may be implemented as blocks  418 - 422  of  FIG.  4   . At block  418 , the terminal device calculates a product between the first channel matrix and a conjugate transpose matrix of the second channel matrix. This may be denoted as A=H 1 H 2   H . At block  420 , the terminal device calculates a ratio between a sum (denoted as P d ) of powers of diagonal elements of the product and a sum (denoted as P) of powers of all elements of the product. When the ratio (denoted as P d /P) is above (greater than or equal to) a predetermined threshold, the terminal device determines that the two channels are the same channel at block  422 . The threshold may be determined by considering various factors of the system. Simulations may be done to evaluate the performance loss against different values of the threshold to determine a proper value. Note that there might be some delay between the two channels. It has been proven in field that the timing tolerance for relatively static terminal device is up to 20 ms. Also note that various existing techniques for evaluating the similarity between matrixes may be used instead. 
     Referring back to  FIG.  2   , when detecting that frequency bands used by the two operators for the cell are overlapped, the terminal device performs measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands at block  204 . At block  206 , the terminal device reports information about a result of the measurement to the two operators. With the measurement configuration described above, the terminal device may know what measurement result needed to be reported and when to report such result to the corresponding operator. For example, the measurement on the CSI-RS may be used for generating a CSI report which helps the base station&#39;s downlink transmission. The measurement on the CSI-RS may also be optionally used for helping the terminal device and the base station to do radio link monitoring. It may also be optionally used by the base station for sending handover command to the terminal device. The measurement on the TRS may help the terminal device to adjust time/frequency of the terminal device. 
     In the method shown in  FIG.  2   , since the reference signal from one of the two operators is measured and the result is reused for measurement reporting, the power consumption at the terminal device can be reduced. If the two operators share the same radio, 50% power saving at maximum can be expected from the perspectives of measurements and control channel monitoring. These two factors dominant the power saving of the terminal device in cases of non-heavy data traffic. 
     Blocks  204  and  206  may be performed depending on different cases of frequency band overlapping. For example, in case A of  FIG.  5   , since the two frequency bands are the same with each other, the measurement is performed at the same frequency band at block  204  and the information sent to the two operators at block  206  indicate the same result of the measurement. In other words, the terminal device may do only one measurement for multiple operators and reuse the same measurement for all. In case B of  FIG.  5   , since the overlapped portion of the frequency bands is the second frequency band, the measurement is performed at the first frequency band at block  204  and the information sent to the second operator at block  206  indicates part of the result of the measurement corresponding to the second frequency band. In other words, the terminal device may do measurement for the operator with the widest band and then extract the measurement result for the one with smaller band. In case C of  FIG.  5   , since the two frequency bands are staggered from each other with a portion overlapped therebetween, the measurement is performed at the overlapped portion at block  204  and the information sent to the two operators at block  206  contains the same result of the measurement. In other words, the terminal device may do only one measurement for the partial band overlapped by multiple operators. 
     Blocks  204  and  206  may also be performed depending on different cases of DRX configurations. The DRX configurations may be obtained from the RRC (re)configurations described above. For example, in case 1 of  FIG.  6   , DRX periods of the two operators are completely overlapped with each other. In this case, the measurement is performed at one of measurement opportunities for the two operators, which is closest to the earliest one of reporting occasions for the two operators.  FIG.  7    illustrates an example for the case of periodic CSI reporting. As shown, CSI reporting occasions from different operators may be grouped and the earliest one may be taken. In addition, only the closest measurement opportunity prior to the earliest reporting occasion may be employed. As a result, the terminal device may ignore the measurement opportunities between the last CSI reporting and the measurement opportunity employed. 
     In case 2 of  FIG.  6   , the second DRX period of the second operator falls within the first DRX period of the first operator For example, the first DRX period may be a multiple of the second DRX period. In this case, since the measurement reporting for the second operator needs to be more frequent than the first operator, the measurement is performed at a measurement opportunity for the second operator, without using measurement opportunity for the first operator. In case 3 of  FIG.  6   , DRX periods of the two operators are staggered from each other with a portion overlapped therebetween. In this case, the measurement is performed at a measurement opportunity for one of the two operators whose DRX period starts earlier. In this way, the measurement result obtained earlier for one operator may be reused for the other operator. Note that the above case 1 to case 3 in  FIG.  6    may apply to case A and case C in  FIG.  5   . For case B, the measurement opportunity for the first operator is always used for performing the measurement. 
       FIG.  8    is a flowchart illustrating a method implemented at a terminal device according to another embodiment of the disclosure. As shown, the method comprises blocks  202 - 206  and  824 - 828 . Blocks  202 - 206  have been described above and its details are omitted here. At block  824 , the terminal device determines whether a same neighboring cell is to be measured for the two operators. Note that there may be one or more same neighboring cells to be measured for the two operators. This determination may be performed according to the carrier bands of neighboring cells. When determining that a same neighboring cell is to be measured for the two operators, the terminal device performs measurement on the same neighboring cell only one time at block  820 . The measurement may comprise inter-frequency cell measurement and intra-frequency cell measurement. In the case of inter-frequency cell measurement, the measurement gap, measurement period and measurement offset may be obtained from the RRC (re)configuration described above. The measurement result obtained in a measurement gap for one operator may be reused for the other operator. At block  822 , the terminal device reports information indicating the same result of the measurement to the two operators. With the method of  FIG.  8   , the power consumption at the terminal device can be further reduced. 
       FIG.  9    is a block diagram showing an apparatus suitable for use in practicing some embodiments of the disclosure. For example, the access network node described above may be implemented through the apparatus  900 . As shown, the apparatus  900  may include a processor  910 , a memory  920  that stores a program, and optionally a communication interface  930  for communicating data with other external devices through wired and/or wireless communication. 
     The program includes program instructions that, when executed by the processor  910 , enable the apparatus  900  to operate in accordance with the embodiments of the present disclosure, as discussed above. That is, the embodiments of the present disclosure may be implemented at least in part by computer software executable by the processor  910 , or by hardware, or by a combination of software and hardware. 
     The memory  920  may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memories, magnetic memory devices and systems, optical memory devices and systems, fixed memories and removable memories. The processor  910  may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi-core processor architectures, as non-limiting examples. 
       FIG.  10    is a block diagram showing a terminal device according to an embodiment of the disclosure. As shown, the terminal device  1000  comprises a detection module  1002 , a measurement module  1004  and a reporting module  1006 . The detection module  1002  may be configured to detect, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped, as described above with respect to block  202 . The measurement module  1004  may be configured to, when detecting that frequency bands used by the two operators for the cell are overlapped, perform measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands, as described above with respect to block  204 . The reporting module  1006  may be configured to report information about a result of the measurement to the two operators, as described above with respect to block  206 . The modules described above may be implemented by hardware, or software, or a combination of both. 
     With reference to  FIG.  11   , in accordance with an embodiment, a communication system includes telecommunication network  3210 , such as a 3GPP-type cellular network, which comprises access network  3211 , such as a radio access network, and core network  3214 . Access network  3211  comprises a plurality of base stations  3212   a ,  3212   b ,  3212   c , such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area  3213   a ,  3213   b ,  3213   c . Each base station  3212   a ,  3212   b ,  3212   c  is connectable to core network  3214  over a wired or wireless connection  3215 . A first UE  3291  located in coverage area  3213   c  is configured to wirelessly connect to, or be paged by, the corresponding base station  3212   c . A second UE  3292  in coverage area  3213   a  is wirelessly connectable to the corresponding base station  3212   a . While a plurality of UEs  3291 ,  3292  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 UE is connecting to the corresponding base station  3212 . 
     Telecommunication network  3210  is itself connected to host computer  3230 , 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  3230  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  3221  and  3222  between telecommunication network  3210  and host computer  3230  may extend directly from core network  3214  to host computer  3230  or may go via an optional intermediate network  3220 . Intermediate network  3220  may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network  3220 , if any, may be a backbone network or the Internet; in particular, intermediate network  3220  may comprise wo or more sub-networks (not shown). 
     The communication system of  FIG.  11    as a whole enables connectivity between the connected UEs  3291 ,  3292  and host computer  3230 . The connectivity may be described as an over-the-top (OTT) connection  3250 . Host computer  3230  and the connected UEs  3291 ,  3292  are configured to communicate data and/or signaling via OTT connection  3250 , using access network  3211 , core network  3214 , any intermediate network  3220  and possible further infrastructure (not shown) as intermediaries. OTT connection  3250  may be transparent in the sense that the participating communication devices through which OTT connection  3250  passes are unaware of routing of uplink and downlink communications. For example, base station  3212  may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer  3230  to be forwarded (e.g., handed over) to a connected UE  3291 . Similarly, base station  3212  need not be aware of the future routing of an outgoing uplink communication originating from the UE  3291  towards the host computer  3230 . 
     Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to  FIG.  12   . In communication system  3300 , host computer  3310  comprises hardware  3315  including communication interface  3316  configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system  3300 . Host computer  3310  further comprises processing circuitry  3318 , which may have storage and/or processing capabilities. In particular, processing circuitry  3318  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  3310  further comprises software  3311 , which is stored in or accessible by host computer  3310  and executable by processing circuitry  3318 . Software  3311  includes host application  3312 . Host application  3312  may be operable to provide a service to a remote user, such as UE  3330  connecting via OTT connection  3350  terminating at UE  3330  and host computer  3310 . In providing the service to the remote user, host application  3312  may provide user data which is transmitted using OTT connection  3350 . 
     Communication system  3300  further includes base station  3320  provided in a telecommunication system and comprising hardware  3325  enabling it to communicate with host computer  3310  and with UE  3330 . Hardware  3325  may include communication interface  3326  for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system  3300 , as well as radio interface  3327  for setting up and maintaining at least wireless connection  3370  with UE  3330  located in a coverage area (not shown in  FIG.  12   ) served by base station  3320 . Communication interface  3326  may be configured to facilitate connection  3360  to host computer  3310 . Connection  3360  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  3325  of base station  3320  further includes processing circuitry  3328 , 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. Base station  3320  further has software  3321  stored internally or accessible via an external connection. 
     Communication system  3300  further includes UE  3330  already referred to. Its hardware  3335  may include radio interface  3337  configured to set up and maintain wireless connection  3370  with a base station serving a coverage area in which UE  3330  is currently located. Hardware  3335  of UE  3330  further includes processing circuitry  3338 , 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  3330  further comprises software  3331 , which is stored in or accessible by UE  3330  and executable by processing circuitry  3338 . Software  3331  includes client application  3332 . Client application  3332  may be operable to provide a service to a human or non-human user via UE  3330 , with the support of host computer  3310 . In host computer  3310 , an executing host application  3312  may communicate with the executing client application  3332  via OTT connection  3350  terminating at UE  3330  and host computer  3310 . In providing the service to the user, client application  3332  may receive request data from host application  3312  and provide user data in response to the request data. OTT connection  3350  may transfer both the request data and the user data. Client application  3332  may interact with the user to generate the user data that it provides. 
     It is noted that host computer  3310 , base station  3320  and UE  3330  illustrated in  FIG.  12    may be similar or identical to host computer  3230 , one of base stations  3212   a ,  3212   b ,  3212   c  and one of UEs  3291 ,  3292  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  3350  has been drawn abstractly to illustrate the communication between host computer  3310  and UE  3330  via base station  3320 , 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  3330  or from the service provider operating host computer  3310 , or both. While OTT connection  3350  is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of toad balancing consideration or reconfiguration of the network). 
     Wireless connection  3370  between UE  3330  and base station  3320  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  3330  using OTT connection  3350 , in which wireless connection  3370  forms the last segment. More precisely, the teachings of these embodiments may improve the power consumption. 
     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  3350  between host computer  3310  and UE  3330 , in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection  3350  may be implemented in software  3311  and hardware  3315  of host computer  3310  or in software  3331  and hardware  3335  of UE  3330 , or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection  3350  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  3311 ,  3331  may compute or estimate the monitored quantities. The reconfiguring of OTT connection  3350  may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station  3320 , and it may be unknown or imperceptible to base station  3320 . Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer  3310 &#39;s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software  3311  and  3331  causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection  3350  while it monitors propagation times, errors etc. 
       FIG.  13    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS.  11  and  12   . For simplicity of the present disclosure, only drawing references to  FIG.  13    will be included in this section. In step  3410 , the host computer provides user data. In substep  3411  (which may be optional) of step  3410 , the host computer provides the user data by executing a host application. In step  3420 , the host computer initiates a transmission carrying the user data to the UE. In step  3430  (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step  3440  (which may also be optional), the UE executes a client application associated with the host application executed by the host computer. 
       FIG.  14    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS.  11  and  12   . For simplicity of the present disclosure, only drawing references to  FIG.  14    will be included in this section. In step  3510  of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step  3520 , the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step  3530  (which may be optional), the UE receives the user data carried in the transmission. 
       FIG.  15    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS.  11  and  12   . For simplicity of the present disclosure, only drawing references to  FIG.  15    will be included in this section. In step  3610  (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step  3620 , the UE provides user data. In substep  3621  (which may be optional) of step  3620 , the UE provides the user data by executing a client application. In substep  3611  (which may be optional) of step  3610 , the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep  3630  (which may be optional), transmission of the user data to the host computer. In step  3640  of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure. 
       FIG.  16    is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to  FIGS.  11  and  12   . For simplicity of the present disclosure, only drawing references to  FIG.  16    will be included in this section. In step  3710  (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step  3720  (which may be optional), the base station initiates transmission of the received user data to the host computer. In step  3730  (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. 
     According to an aspect of the disclosure, there is provided a method implemented in a communication system including a host computer, a base station and a terminal device. The method may comprise, at the host computer, providing user data. The method may further comprise, at the host computer, initiating a transmission carrying the user data to the terminal device via a cellular network comprising the base station. The terminal device may detect, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. When detecting that frequency bands used by the two operators for the cell are overlapped, the terminal device may perform measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The terminal device may report information about a result of the measurement to the two operators. 
     In an embodiment of the disclosure, the method may further comprise, at the terminal device, receiving the user data from the base station. 
     According to another aspect of the disclosure, there is provided a communication system including a host computer comprising processing circuitry configured to provide user data and a communication interface configured to forward user data to a cellular network for transmission to a terminal device. The terminal device may comprise a radio interface and processing circuitry. The processing circuitry of the terminal device may be configured to detect, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. The processing circuitry of the terminal device may be further configured to, when detecting that frequency bands used by the two operators for the cell are overlapped, perform measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The processing circuitry of the terminal device may be further configured to report information about a result of the measurement to the two operators. 
     In an embodiment of the disclosure, the communication system may further include the terminal device. 
     In an embodiment of the disclosure, the cellular network may further include a base station configured to communicate with the terminal device. 
     In an embodiment of the disclosure, the processing circuitry of the host computer may be configured to execute a host application, thereby providing the user data. The processing circuitry of the terminal device may be configured to execute a client application associated with the host application. 
     According to another aspect of the disclosure, there is provided a method implemented in a communication system including a host computer, a base station and a terminal device. The method may comprise, at the host computer, receiving user data transmitted to the base station from the terminal device. The terminal device may detect, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. When detecting that frequency bands used by the two operators for the cell are overlapped, the terminal device may perform measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The terminal device may report information about a result of the measurement to the two operators. 
     In an embodiment of the disclosure, the method may further comprise, at the terminal device, providing the user data to the base station. 
     In an embodiment of the disclosure, the method may further comprise, at the terminal device, executing a client application, thereby providing the user data to be transmitted. The method may further comprise, at the host computer, executing a host application associated with the client application. 
     In an embodiment of the disclosure, the method may further comprise, at the terminal device, executing a client application. The method may further comprise, at the terminal device, receiving input data to the client application. The input data may be provided at the host computer by executing a host application associated with the client application. The user data to be transmitted may be provided by the client application in response to the input data. 
     According to another aspect of the disclosure, there is provided a communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a terminal device to a base station. The terminal device may comprise a radio interface and processing circuitry. The processing circuitry of the terminal device may be configured to detect, for a cell that is shared by two operators and to be measured by the terminal device, whether frequency bands used by the two operators for the cell are overlapped. The processing circuitry of the terminal device may be further configured to, when detecting that frequency bands used by the two operators for the cell are overlapped, perform measurement on a reference signal from one of the two operators at least at the overlapped portion of the frequency bands. The processing circuitry of the terminal device may be further configured to report information about a result of the measurement to the two operators. 
     In an embodiment of the disclosure, the communication system may further include the terminal device. 
     In an embodiment of the disclosure, the communication system may further include the base station. The base station may comprise a radio interface configured to communicate with the terminal device and a communication interface configured to forward to the host computer the user data carried by a transmission from the terminal device to the base station. 
     In an embodiment of the disclosure, the processing circuitry of the host computer may be configured to execute a host application. The processing circuitry of the terminal device may be configured to execute a client application associated with the host application, thereby providing the user data. 
     In an embodiment of the disclosure, the processing circuitry of the host computer may be configured to execute a host application, thereby providing request data. The processing circuitry of the terminal device may be configured to execute a client application associated with the host application, thereby providing the user data in response to the request data. 
     In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the disclosure is not limited thereto. While various aspects of the exemplary embodiments of this disclosure may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. 
     As such, it should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be practiced in various components such as integrated circuit chips and modules. It should thus be appreciated that, the exemplary embodiments of this disclosure may be realized in an apparatus that is embodied as an integrated circuit, where the integrated circuit may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor, a digital signal processor, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this disclosure. 
     It should be appreciated that at least some aspects of the exemplary embodiments of the disclosure may be embodied in computer-executable instructions, such as in one or more program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types when executed by a processor in a computer or other device. The computer executable instructions may be stored on a computer readable medium such as a hard disk, optical disk, removable storage media, solid state memory, RAM, etc. As will be appreciated by one skilled in the art, the function of the program modules may be combined or distributed as desired in various embodiments. In addition, the function may be embodied in whole or in part in firmware or hardware equivalents such as integrated circuits, field programmable gate arrays (FPGA), and the like. 
     References in the present disclosure to “one embodiment”, “an embodiment” and so on, indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. It should be noted that two blocks shown in succession in the figures may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. 
     It should be understood that, although the terms “first”, “second” and so on may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of the disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed terms. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and/or “including”, when used herein, specify the presence of stated features, elements, and/or components, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. The terms “connect”, “connects”, “connecting” and/or “connected” used herein cover the direct and/or indirect connection between two elements. 
     The present disclosure includes any novel feature or combination of features disclosed herein either explicitly or any generalization thereof. Various modifications and adaptations to the foregoing exemplary embodiments of this disclosure may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this disclosure.