Patent Application
20230422229
The disclosure relates to a wireless communication system. More particularly, the disclosure relates to an apparatus and method for resource allocation in the wireless communication system.
To meet a demand on wireless data traffic which has been in an increasing trend after a 4th generation (4G) communication system was commercialized, there is an ongoing effort to develop an improved 5th generation (5G) communication system or a pre-5G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a beyond 4G network communication system or a post long term evolution (LTE) system.
To achieve a high data transfer rate, the 5G communication system is considered to be implemented in a millimeter wave (mmWave) band (e.g., such as a 60 gigahertz (GHz) band). To reduce a propagation path loss at the mmWave band and to increase a propagation delivery distance, beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna techniques are under discussion in the 5G communication system.
In addition, to improve a network of a system, techniques, such as an evolved small cell, an advanced small cell, a cloud radio access network (RAN), an ultra-dense network, device to device (D2D) communication, a wireless backhaul, a moving network, cooperative communication, coordinated multi-points (CoMP), and reception interference cancellation, or the like are being developed in the 5G communication system.
In addition thereto, hybrid frequency shift keying and quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM) technique and filter bank multi carrier (FBMC), non orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), or the like as an advanced access technology are being developed in the 5G system.
With the rapid increase in the use of electronic devices, such as smartphones, laptops, and tablets, which are always carried and used by people, there is an exponential growth of a demand for wireless data transmission. As one of various ways of meeting such a user's demand, a dual connectivity (DC) technology has been introduced in 3rd generation partnership project (3GPP) Release 12. The DC technology allows the electronic device to perform data transmission by accessing a master node (MN) and a secondary node (SN) simultaneously to use a plurality of carriers, thereby increasing a user's data transfer rate and providing mobility robustness.
The above information is presented as background information only to assist with an understanding of the disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the disclosure.
Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide an apparatus and method for increasing a data transfer rate when operating dual connectivity (DC) in a wireless communication system.
Another aspect of the disclosure is to provide an apparatus and method for selecting a best band combination by considering a data rate and a latency when operating DC in a wireless communication system.
Another aspect of the disclosure is to provide an apparatus and method for operating a base station in an optimal manner in a multi-radio dual connectivity (MR-DC) in a wireless communication system.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
In accordance with an aspect of the disclosure, a secondary node (SN) apparatus is provided. The SN apparatus includes a transceiver and a processor operatively coupled to the transceiver. The processor may be configured to receive a request message from a master node (MN), wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of a master cell group (MCG) for each of the at least one band combination, identify a band combination from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of a secondary cell group (SCG), and transmit a response message including information indicating the identified band combination to the MN.
In accordance with another aspect of the disclosure, a master node (MN) apparatus is provided. The MN apparatus includes a transceiver, and a processor operatively coupled to the transceiver. The processor may be configured to transmit a request message to an SN, wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of an MCG for each of the at least one band combination, and receive a response message including information indicating the identified band combination from the SN. The band combination may be identified from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of an SCG.
In accordance with another aspect of the disclosure, a method of operating an SN is provided. The method includes receiving a request message from an MN, wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of an MCG for each of the at least one band combination, identifying a band combination from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of an SCG, and transmitting a response message including information indicating the identified band combination to the MN.
In accordance with another aspect of the disclosure, a method of operating an MN apparatus is provided. The method includes transmitting a request message to an SN, wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of an MCG for each of the at least one band combination, and receiving a response message including information indicating the identified band combination from the SN. The band combination may be identified from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of an SCG.
An apparatus and method according to various embodiments of the disclosure allow a master node (MN) and a secondary node (SN) to operate efficiently by selecting a best band combination in a multi-radio dual connectivity (MR-DC).
Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
The same reference numerals are used to represent the same elements throughout the drawings.
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
Terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those ordinarily skilled in the art disclosed in the disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Optionally, the terms defined in the disclosure should not be interpreted to exclude the embodiments of the disclosure.
A hardware-based approach is described for example in the various embodiments of the disclosure described hereinafter. However, since the various embodiments of the disclosure include a technique in which hardware and software are both used, a software-based approach is not excluded in the embodiments of the disclosure.
Terms used hereinafter in relation to a message (e.g., a signal, a message, information, signaling, data), terms related to multiple connectivity (e.g., dual connectivity (DC), multi-radio access technology (RAT) (MR)-DC, a cell group, a master cell group (MCG), a secondary cell group (SCG)), terms referring to a signal (e.g., a reference signal, system information, a control signal, a message, data), and terms referring to network entities (e.g., a communication node, a radio node, a radio unit, a network node, a master node (MN), a secondary node (SN), a transmission/reception point (TRP), a digital unit (DU), a radio unit (RU), a massive MIMO unit (MMU)) or the like are exemplified for convenience of explanation. Therefore, the disclosure is not limited to the terms described below, and thus other terms having the same technical meaning may also be used.
In addition, although the disclosure describes various embodiments by using terms used in some communication standards (e.g., 3rd generation partnership project (3GPP)), this is for exemplary purposes only. Various embodiments of the disclosure may be easily modified and applied to other communication systems.
Referring to
The base stations 110-1, 110-2, . . . , 110-n are network infrastructures which provide radio access to the terminal 120. The base station 110 has coverage defined as a specific geographical area, based on a distance capable of transmitting a signal. The term ‘coverage’ used hereinafter may refer to a service coverage area in the base station 110. The base station 110 may cover one cell, or may cover multiple cells. Herein, the multiple cells may be divided by a supported frequency and an area of a covered sector.
In addition to the term ‘base station’, the base station 110 may be referred to as an ‘access point (AP)’, an ‘eNodeB (eNB)’, a ‘5th generation (5G) node’, a ‘5G NodeB (NB)’, a ‘next generation Node B (gNB)’, a ‘wireless point’, a ‘transmission/reception point (TRP)’, a ‘distributed unit (DU)’, a ‘radio unit (RU)’, a remote radio head (RRH), or other terms having equivalent technical meanings. According to various embodiments of the disclosure, the base station 110 may be coupled to at least one TRP. The base station 110 may transmit a downlink signal or receive an uplink signal with respect to the terminal 120 through the at least one TRP.
As a device used by a user, the terminal 120 communicates with the base station 110 through the radio channel. Optionally, the terminal 120 may be operated without user involvement. For example, as a device for performing machine type communication (MTC), the terminal 120 may not be carried by the user. In addition to the term ‘terminal’, the terminal 120 may be referred to as a ‘user equipment (UE)’, a ‘mobile station’, a ‘subscriber station’, a ‘customer premises equipment (CPE)’, a ‘remote terminal’, a ‘wireless terminal’, an ‘electronic device’, a ‘vehicle terminal’, a ‘user device’, or other terms having equivalent technical meanings.
A dual connectivity (DC) technology is one type of multiple-connectivity technologies introduced from the 3rd generation partnership project (3GPP) standard release 12. In the DC technology, a terminal is simultaneously coupled to two independent heterogeneous or homogeneous wireless communication cell groups having a separate radio resource control entity, and a frequency resource on a component carrier of a cell in each cell group located in a different frequency band is used for signal transmission/reception to increase frequency use efficiency of the terminal and a base station. The DC consists of a master cell group in which a control plane is directly coupled to a core network to manage a radio resource control state of the terminal and a secondary cell group associated with the master cell group.
A carrier aggregation (CA) technology is a technology introduced in the 3GPP standard release 10. In the CA technology, the terminal is coupled to a homogenous wireless communication cell group having a common radio resource control entity, and a frequency resource on a component carrier of each cell located in a different frequency band is used for signal transmission/reception to increase frequency use efficiency of the terminal and the base station.
Due to technical advantages of increasing efficiency in using limited wireless communication resources of the terminal and base station, the DC technology and the CA technology are actively studied in academic terms. More particularly, a 5G mobile communication system uses a non-stand alone type in which an operation is achieved in association with a 4G core network as a basic operation scheme, which is utilized as a core technology in a commercial service supporting the 5G mobile communication system.
In various embodiments of the disclosure, a situation in which the base stations 110-1, 110-2, . . . , 110-n are coupled to the terminal 120 through multiple connectivity is described. As described above, the multiple connectivity refers to a communication technology in which the terminal 210 is coupled to each of the base stations 110-1, 110-2, . . . , 110-n through an independent radio access technology (RAT). For example, the terminal 120 may be coupled to each of two base stations through dual connectivity (DC) which is one type of the multiple connectivity. For example, the terminal 120 may be coupled to an eNB base station through long term evolution (LTE), and may be coupled to a gNB base station through new radio (NR). Each base station may be referred to as a communication node. One or more cells provided in one base station may be referred to as a cell group. For example, the base station may support one or more cell groups. A base station which provides a master cell group (MCG) may provide a master node (MN), and a base station which provides a secondary cell group (SCG) may provide a secondary node (SN).
Referring to
The base station 200 includes a wireless communication unit 201, a backhaul communication unit 203, a storage unit 205, and a control unit 207.
The wireless communication unit 201 performs functions for transmitting and receiving a signal through a radio channel. For example, the wireless communication unit 201 performs a function of conversion between a baseband signal and a bit-stream according to a physical layer standard of a system. For example, in data transmission, the wireless communication unit 201 generates complex symbols by coding and modulating a transmission bit-stream. In addition, in data reception, the wireless communication unit 201 restores a reception bit-stream by demodulating and decoding a baseband signal. In addition, the wireless communication unit 201 up-converts a baseband signal into a radio frequency (RF) signal and thereafter transmits it through an antenna, and down-converts an RF signal received through the antenna into a baseband signal.
For this, the wireless communication unit 201 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), or the like. In addition, the wireless communication unit 201 may include a plurality of transmission/reception paths. Further, the wireless communication unit 201 may include at least one antenna array constructed of a plurality of antenna elements. From a hardware aspect, the wireless communication unit 201 may be constructed of a digital unit and an analog unit, and the analog unit may be constructed of a plurality of sub-units according to operating power, operating frequency, or the like. According to various embodiments of the disclosure, the wireless communication unit 201 may include a unit of forming a beam, i.e., a beamforming unit. For example, the wireless communication unit 201 may include a Massive MIMO Unit (MMU).
The wireless communication unit 201 may transmit/receive a signal. To this end, the wireless communication unit 201 may include at least one transceiver. For example, the wireless communication unit 201 may transmit a synchronization signal, a reference signal, system information, a message, control information, or data. In addition, the wireless communication unit 201 may perform beamforming. In order to assign a directivity depending on the setting of the control unit 207 to a signal to be transmitted/received, the wireless communication unit 201 may apply a beamforming weight to the signal. According to an embodiment of the disclosure, the wireless communication unit 201 may generate a baseband signal depending on a scheduling result and a transmit power calculation result. In addition, an RF unit in the wireless communication unit 201 may transmit the generated signal through an antenna.
The wireless communication unit 201 transmits and receives a signal as described above. Accordingly, the wireless communication unit 201 may be referred to as a transmitter, a receiver, or a transceiver. In addition, in the following description, transmission and reception performed through a radio channel are used to imply that the aforementioned processing is performed by the wireless communication unit 201.
The backhaul communication unit 203 provides an interface for preforming communication with different nodes in a network. For example, the backhaul communication unit 203 converts a bit-stream transmitted from the base station 200 to a different node, e.g., a different access node, a different base station, an upper node, a core network, or the like, into a physical signal, and converts a physical signal received from the different node into a bit-stream.
The storage unit 205 stores data, such as a basic program, application program, configuration information, or the like for an operation of the base station 200. The storage unit 205 may include a memory. The storage unit 205 may be constructed of a volatile memory, a non-volatile memory, or a combination of the volatile memory and the non-volatile memory. In addition, the storage unit 205 may provide the stored data according to a request of the control unit 207.
The control unit 207 controls overall operations of the base station 200. For example, the control unit 207 may transmit and receive a signal via the communication unit 201 or the backhaul communication unit 203. Further, the control unit 207 writes and reads data in the storage unit 205. In addition, the control unit 207 may perform functions of a protocol stack required in a communication specification. To this end, the control unit 207 may include at least one processor.
The structure of the base station 200 illustrated in
Although the base station is described as one entity in
Referring to
The communication unit 301 performs functions for transmitting and receiving a signal through a radio channel. For example, the communication unit 301 performs a function of conversion between a baseband signal and a bit-stream according to a physical layer standard of a system. For example, in data transmission, the communication unit 301 generates complex symbols by coding and modulating a transmission bit-stream. In addition, in data reception, the communication unit 301 restores a reception bit-stream by demodulating and decoding a baseband signal. In addition, the communication unit 301 up-converts a baseband signal into an RF signal and thereafter transmits it through an antenna, and down-converts an RF signal received through the antenna into a baseband signal. For example, the communication unit 301 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, or the like.
In addition, the communication unit 301 may include a plurality of transmission/reception paths. Further, the communication unit 301 may include an antenna unit. The communication unit 301 may include at least one antenna array constructed of a plurality of antenna elements. From a hardware aspect, the communication unit 301 may be constructed of a digital circuit and an analog circuit (e.g., a radio frequency integrated circuit (RFIC)). Herein, the digital circuit and the analog circuit may be implemented as one package. In addition, the communication unit 301 may include a plurality of RF chains. In addition, the communication unit 301 may perform beamforming. In order to assign a directivity depending on the setting of the control unit 305 to a signal to be transmitted/received, the communication unit 301 may apply a beamforming weight to the signal. According to an embodiment of the disclosure, the communication unit 301 may include a radio frequency (RF) block (or RF unit). The RF block may include a first RF circuity related to the antenna and a second RF circuity related to baseband processing. The first RF circuity may be referred to as RF-Antenna (RF-A). The second RF circuity may be referred to as RF-Baseband (RF-B).
In addition, the communication unit 301 may transmit/receive a signal. To this end, the communication unit 301 may include at least one transceiver. The communication unit 301 may receive a downlink signal. The downlink signal may include a synchronization signal (SS), a reference signal (RS) (e.g., cell-specific reference signal (CRS), demodulation (DM)-RS), system information (e.g., MIB, SIB, remaining system information (RMSI), other system information (OSI)), a configuration message, control information, or downlink data, etc. In addition, the communication unit 301 may transmit an uplink signal. The uplink signal may include a random access-related signal (e.g., random access preamble (RAP) (message 1 (Msg1), message 3 (Msg3))), a reference signal (e.g., sounding reference signal (SRS), DM-RS), or a power headroom report (PHR), or the like.
In addition, the communication unit 301 may include different communication modules to process signals of different frequency bands. Further, the communication unit 301 may include a plurality of communication modules to support a plurality of different radio access technologies. For example, the different radio access technologies may include a Bluetooth low energy (BLE), a wireless fidelity (Wi-Fi), a Wi-Fi gigabyte (WiGig), a cellular network (e.g., long term evolution (LTE), new radio (NR)), or the like. In addition, the different frequency bands may include a super high frequency (SHF) (e.g., 2.5 GHz, 5 GHz) band and a millimeter wave (e.g., 38 GHz, 60 GHz etc.) band. In addition, the communication unit 301 may use the same-type radio access technology on different frequency bands (e.g., an unlicensed band for licensed assisted access (LAA), Citizens broadband radio service (CBRS) (e.g., 3.5 GHz)).
The communication unit 301 transmits and receives a signal as described above. Accordingly, the communication unit 301 may be referred to as a transmitter, a receiver, or a transceiver. In addition, in the following description, transmission and reception performed through a radio channel are used to imply that the aforementioned processing is performed by the communication unit 301.
The storage unit 303 stores data, such as a basic program, application program, configuration information, or the like for an operation of the UE 300. The storage unit 303 may be constructed of a volatile memory, a non-volatile memory, or a combination of the volatile memory and the non-volatile memory. In addition, the storage unit 303 may provide the stored data according to a request of the control unit 305. According to various embodiments of the disclosure, the storage unit 303 may store each beam of a beam set to be operated in the UE 300 or direction information on each beam of an auxiliary beam pair.
The control unit 305 controls overall operations of the UE 300. For example, the control unit 305 may transmit and receive a signal via the communication unit 301. Further, the control unit 305 writes and reads data in the storage unit 303. In addition, the control unit 305 may perform functions of a protocol stack required in a communication specification. To this end, the control unit 305 may include at least one processor. The control unit 305 may include at least one processor or micro-processor, or may be part of the processor. In addition, part of the communication unit 301 and the control unit 305 may be referred to as a CP. The control unit 305 may include various modules for performing communication. According to various embodiments of the disclosure, the control unit 305 may control the UE to perform operations based on various embodiments described above.
The disclosure relates to a method and apparatus for providing a band combination capable of providing an optimal service to a UE under a dual connectivity (DC) structure.
A band combination (BC) in a wireless communication system may be understood as a combination of bands used in communication between a UE and a base station. In order to provide optimal communication to the UE, the base station may determine a band combination in which the UE is capable of obtaining an optimal data throughput. An optimal service may be provided to the UE according to such a band combination.
In order to determine a best band combination, the base station may request the UE to provide information on a band combination supportable by the UE. At the request of the base station, the UE may transmit, to the base station, UE BC information regarding the band combination supportable by the UE. Information on at least one band combination supportable by the UE may be included in the UE BC information. The UE BC information may be included in UE capability information to be transmitted by the UE to the base station.
Information on a band combination included in the UE BC information may be determined according to a radio access technology (RAT) used by the base station. If the base station supports an LTE network, the UE may transmit BC information including an LTE band to the base station. If the base station supports an NR network, the UE may transmit BC information including an NR band to the base station. If the base station supports the LTE network and the NR network, the UE may transmit BC information including at least one of the LTE band and the NR band to the base station. For example, if the base station uses only LTE, the UE BC information may not include a band combination including the NR band among band combinations supportable by the UE. As another example, if the base station uses both LTE and NR, the UE BC information may include both the LTE band and the NR band. As another example, if the base station uses only NR, the UE BC information may not include a band combination including the LTE band among band combinations supportable by the UE.
The base station may need to provide an optimal service to the UE, and may measure a data rate to determine whether the optimal service is provided. The data rate means an amount of data transmitted during a reference time, and may be measured in units of bps.
In an embodiment of the disclosure, the data rate may be determined in an NR-based wireless communication system, based on the following equation.
In Equation 1, J denotes the number of aggregated component carriers in a band or a band combination, and Rmax denotes 948/1024. In addition, for a j-th component carrier, vLyeses(j) denotes the maximum number of supportable layers, Qm(j) denotes a maximum supportable modulation order, f(j) denotes a scaling factor, μ denotes a numerology, TSμ denotes a duration of an orthogonal frequency division multiplexing (OFDM) symbol in a subframe for the numerology of μ, NPRBBW(j),μ denotes resource block (RB) allocation in a bandwidth BW(j) having the numerology of μ, and OH(j) denotes overhead.
In an embodiment of the disclosure, the data rate in an LTE-based wireless communication system may be determined based on the following equation.
Data rate=10−3·Σj=1JTBSj Equation 2
In Equation 2 above, J denotes the number of LTE component carriers in a multi-radio DC (MR-DC) band combination, TBSj denotes the total maximum number of transmit block bits of a downlink shared channel (DL-SCH), received in a transmission time interval (TTI) of 1 ms for a j-th component carriers, that is, a transport block size (TBS).
As described in Equation 1 and Equation 2 above, it may be known that each of factors of determining the data rate is determined according to a band combination. Therefore, it is required to determine a best band combination in order to provide a UE with a service having an optimal data rate.
Referring to
In an embodiment of the disclosure, the MN 403 and the SN need to determine a band combination, in order to determine a band combination to be used by the MN 403, the SN, and the UE under the DC structure. In order to determine the band combination, the MN 403 may transmit, to the SN, MN BC information regarding an MN band combination usable by the MN 403.
Although not shown in the figure, prior to operation 421, the MN403 may receive, from the UE, UE band combination information usable by the UE. The UE band combination information may include information on at least one band combination usable by the UE. The MN 403 may select at least one band combination usable by the MN 403 from among UE band combination information. The MN 403 may measure a data rate for each of the at least one band combination. The MN403 may measure a data rate for each of the at least one band combination, based on Equation 2 described above. The MN 403 may select at least one band combination usable by the MN 403, based on the measured data rate for each band combination. For example, since it is difficult to obtain a desired rate in case of communication based on a band combination in which a data rate is measured to be less than or equal to a threshold, the MN 403 may not select this band combination. In order to obtain the desired rate, the MN 403 may select a band combination in which a data rate exceeds a threshold.
The MN 403 may transmit, to the SN 405, MN band combination information including the selected at least one band combination. The MN band combination information may be included in an SN addition request message (e.g., X2AP SgNB addition request) transmitted by the MN 403 to the SN 405 in operation 421. The addition request message transmitted by the MN 403 to the SN 405 may be included in a radio resource control (RRC) container and forwarded through an interface between the MN 403 and the SN 405. In the EN-DC structure, the interface between the MN and the SN may be an X2 application protocol (X2AP).
In operation 423, the SN may transmit, to the MN 403, an SN addition request acknowledge message (e.g., X2AP SgNB addition request acknowledge). The SN addition request acknowledge message may be a response message for the SN addition request message received from the MN 403. The SN addition request acknowledge message may include information required to operate the SN under a DC structure.
In an embodiment of the disclosure, the SN may select a band combination in which a data rate of the SN is the highest from among the MN band combination information received from the MN 403. Specifically, the SN may measure a data rate of a secondary cell group (SCG), for each band combination included in the MN band combination information. The data rate may be measured based on Equation 1 described above. The SN may select a band combination in which the data rate of the SCG is measured to be the highest from among band combinations included in the MN BC information. Information on the band combination in which the data rate of the SCG is measured to be the highest may be included in the SN addition request acknowledge message transmitted by the SN 405 to the MN 403 in operation 423.
In operation 425, the MN 403 may transmit an RRC connection reconfiguration message to a UE 401. In operation 427, the UE 401 may transmit an RRC connection reconfiguration complete message. In operation 429, the MN 403 may transmit an SN reconfiguration complete message (e.g., SgNB reconfiguration complete) to the SN. In operation 431, the UE 401 may perform a random access procedure with an SN 405. In operation 433, the MN 403 may transmit an SN status transfer message to the SN. Information on a packet to be transmitted by the SN to the UE 401 may be included in the SN status transfer message. In operation 435, the MN 403 may forward data to the SN. The MN 403 may forward data to be forwarded to the UE 401 through the SN, from among information on data transmitted to the UE through the MN 403 before DC is configured. In operation 441, the MN 403 may transmit a packet including an end marker (i.e., an end marker packet) to the SN. The end marker packet may include information indicating that there is no more data to be forwarded by the MN 403 to the SN 405.
In operation 437, operation 439, and operation 443, the MN 403 may perform a path update procedure. Specifically, in operation 437, the MN 403 may transmit an E-UTRAN radio access bearer (E-RAB) modification indication message to a mobility management entity (MME) 409. In operation 439, the MME 409 may transmit a bearer modification message to a serving gateway (S-GW) 407. In operation 443, the MME 409 may transmit an E-RAB modification confirmation message to the MN 403.
Although it has been described above under the premise of the EN-DC, this is only an example, and the operation of the MN 403 and SN 405 according to various embodiments of the disclosure is not limited to the aforementioned EN-DC structure. For example, in case of not the EN-DC structure but the NE-DC structure or the NR-NR structure, an access and mobility managing function (AMF) 459, a session management function (SMF), a user plane function (UPF) 457, or the like may be used instead of the MME 409 and the S-GW 407.
In addition, although embodiments of the disclosure have been described under the premise of signaling of an SN addition request message and SN addition request acknowledge message of the MN 403, this is only an example, and the embodiments of the disclosure are not limited thereto. In an embodiment of the disclosure, the embodiments of the disclosure may also be equally applied to a signaling process of an SN modification request message (e.g., SN modification request) and an SN modification request acknowledge message (e.g., SN modification response).
For example, the MN 403 may transmit MN band combination information including the selected at least one band combination to the SN. The MN band combination information may be included in the SN modification request message transmitted by the MN 403 to the SN 405. The SN modification request message transmitted by the MN 403 to the SN 405 may be transmitted through radio resource control (RRC) signaling. In addition, the SN may transmit an SN modification request acknowledge message (e.g., SgNB addition request acknowledge) to the MN 403. The SN modification request acknowledge message may be a response message for the SN addition request message received from the MN 403. The SN addition request acknowledge message may include information required to operate the SN under a DC structure.
Referring to
In an embodiment of the disclosure, the MN 453 and the SN 455 need to determine a band combination, in order to determine a band combination to be used by the MN 453, the SN 455, and the UE under the DC structure. In order to determine the band combination, the MN may transmit, to the SN 455, MN BC information regarding an MN band combination usable by the MN 453.
Although not shown in the figure, prior to operation 471, the MN 453 may receive, from the UE, UE band combination information usable by the UE. The UE band combination information may include information on at least one band combination usable by the UE. The MN 453 may select at least one band combination usable by the MN 453 from among UE band combination information. The MN 453 may measure a data rate for each of the at least one band combination. The MN 453 may measure a data rate for each of the at least one band combination, based on Equation 2 described above. The MN 453 may select at least one band combination usable by the MN 453, based on the measured data rate for each band combination. For example, since it is difficult to obtain a desired rate in case of communication based on a band combination in which a data rate is measured to be less than or equal to a threshold, the MN 453 may not select this band combination. In order to obtain the desired rate, the MN 453 may select a band combination in which a data rate exceeds a threshold.
The MN 453 may transmit, to the SN 455, MN band combination information including the selected at least one band combination. The MN band combination information may be included in an SN addition request message (e.g., XnAP SN addition request) transmitted by the MN 453 to the SN 455 in operation 471. The addition request message transmitted by the MN 453 to the SN 455 may be included in a radio resource control (RRC) container and forwarded through an interface between the MN 453 and the SN 455. In the NR-DC and EN-DC structures, the interface between the MN 453 and the SN 455 may be an Xn Application Protocol (XnAP).
In operation 473-1, the SN 455 may transmit, to the MN 453, an SN addition request acknowledge message (e.g., XnAP SN addition request acknowledge). The SN addition request acknowledge message may be a response message for the SN addition request message received from the MN 453. The SN addition request acknowledge message may include information required to operate the SN 455 under a DC structure.
In an embodiment of the disclosure, the SN 455 may select a band combination in which the band rate of the SN 455 is the highest from among the MN band combination information received from the MN 453. Specifically, the SN 455 may measure a data rate of a secondary cell group (SCG), for each band combination included in the MN band combination information. The data rate may be measured based on Equation 1 described above. The SN 455 may select a band combination in which the data rate of the SCG is measured to be the highest from among band combinations included in the MN BC information. Information on the band combination in which the data rate of the SCG is measured to be the highest may be included in the SN addition request acknowledge message transmitted by the SN 455 to the MN 453 in operation 473-1.
In operation 473-2, the MN 453 may indicate an Xn-U address to the SN 455. A procedure of indicating the Xn-U address may be used to provide a forwarding address from the SN 455 to a previous MN, for all packet data unit (PDU) session resources successfully configured in the MN 453. Through operation 473-2, the forwarding address and Xn-U address information for completing an SN end bearer configuration may be provided from the MN 453 to the SN 455.
In operation 475, the MN 453 may transmit an RRC connection reconfiguration message to a UE 451. In operation 477, the UE 451 may transmit an RRC connection reconfiguration complete message. In operation 479, the MN 453 may transmit an SN reconfiguration complete message (e.g., SN reconfiguration complete) to the SN 455. In operation 481, the UE 451 may perform a random access procedure with an SN 455. In operation 483, the MN 453 may transmit an SN status transfer message to the SN 455. Information on a packet to be transmitted by the SN 455 to the UE 451 may be included in the SN status transfer message. In operation 485, the MN 453 may forward data to the SN 455. The MN 453 may forward data to be forwarded to the UE 451 through the SN 455, from among information on data transmitted to the UE through the MN 453 before DC is configured. In operation 491, the MN 453 may transmit a packet including an end marker (i.e., an end marker packet) to the SN 455. The end marker packet may include information indicating that there is no more data to be forwarded by the MN 453 to the SN 455.
In operation 487, operation 489, and operation 493, the MN 453 may perform a path update procedure. Specifically, in operation 487, the MN 453 may transmit a packet data unit (PDU) session modification indication message to an access and mobility management function (AMF) 459. In operation 489, the AMF may transmit a bearer modification message to a user plane function (UPF) 457. In operation 493, the AMF 459 may transmit a PDU session modification confirmation message to the MN.
Although it has been described above under the premise of the NR-DC or NE-DC, this is only an example, and the operation of the MN 453 and SN 455 according to various embodiments of the disclosure is not limited to the aforementioned NR-DC or NE-DC structure. For example, in case of the EN-DC structure, an MME, an S-GW, or the like may be used instead of the AMF and the UPF 457.
In addition, although embodiments of the disclosure have been described under the premise of signaling of an SN addition request message and SN addition request acknowledge message of the MN 453, this is only an example, and the embodiments of the disclosure are not limited thereto. In an embodiment of the disclosure, the embodiments of the disclosure may also be equally applied to a signaling process of an SN modification request message (e.g., SN modification request) and an SN modification request acknowledge message (e.g., SN modification response).
Referring to
Referring to
The MN may transmit, to the SN, information on a band combination selected by the MN. If the MN simply transmits information on the band combination usable by the MN, the SN may select a band combination in which the data rate of the SCG is the highest from among band combinations selected by the MN.
In this case, since the SN is aware of only information on at least one band combination selected by the MN, it is difficult to select a band combination in which a total sum of a data rate of MCG and a data rate of SCG is the highest.
Referring to
The MN means a base station which provides a master cell group (MSG) in a DC structure. In case of EN-DC, the MN may correspond to an eNB. In case of NE-DC and NR-NR structures, the MN may correspond to a gNB. Although the followings are described under the premise of the EN-DC, this is only an example, and the operation of the MN and SN according to various embodiments of the disclosure is not limited to the EN-DC structure.
Although not shown in the figure, in order to determine a band combination, the MN may request a UE to provide information on a band combination supportable by the UE. At the request of the MN, the UE may transmit, to the base station, UE BC information regarding the band combination supportable by the UE. Information regarding at least one band combination supportable by the UE may be included in the UE BC information. The UE BC information may be included in UE capability information to be transmitted by the UE to the base station.
Referring to
The information on the data rate for each band combination may include a data rate for each band combination of the MN. The information on the data rate for each band combination may include information on a latency and the data rate for each band combination of the MN. The information on the data rate for each band combination may be included in the message in the form of an index, an ID, and a weight.
The information on the data rate for each band combination of the MN may be present for each of at least one band combination usable by the MN. For example, if the number of band combinations usable by the MN is k, the number of pieces of information on a data rate may correspond to k. In order to transmit the information on the data rate for each band combination, the MN may measure a data rate of the MCG for each band combination. The data rate may be measured based on Equation 1 when the MN is a gNB, and may be measured based on Equation 2 when the MN is an eNB.
The MN may transmit, to the SN, a message including band combination information including information on a data rate for each band combination related to MR-DC.
For example, the band combination information may be included in the RRC message in the form as follows.
In Table 1 above, allowedBC-ListMRDC means a list of band combinations usable by the MN to operate the MR-DC. allowedBC-ListMRDC may be constructed of BandCombinationInfoList, and may have a form of a sequence of BandCombinationInfo. bandCombinationIndex means a band combination indicator.
In an embodiment of the disclosure, information on a data rate of the MCG may be included in the message to be transmitted by the MN to the SN in operation 610. The information on the data rate of the MCG may be present for each band combination. Since the information on the data rate of the MCG is included in the message to be transmitted by the MN to the SN, the SN may consider up to the data rate of the MCG for each band combination and thus select a best band combination considering a total amount of the MCG data rate and SCG data rate. The information on the data rate of the MCG may be included in the RRC message in the following form.
In Table 2 above, allowedBC-ListMRDC means a list of band combinations usable by the MN to operate the MR-DC. allowedBC-ListMRDC may be constructed of BandCombinationInfoList, and may have a form of a sequence of BandCombinationInfo. bandCombinationIndex means a band combination indicator.
bandCombinationMCGInfoList means a list of information related to communication performance of the MCG for each band combination included in the band combination usable by the MN. The aforementioned information on the data rate of the MCG for each band combination may include information (expectedDataRate) on the data rate of the MCG for each band combination and information (expectedLatency) on an expected latency of the MCG for each band combination. The data rate may be measured for each band combination, and may be measured based on Equation 1 or Equation 2.
In an embodiment of the disclosure, the data rate may be included in a message including the band combination information usable by the MN in the form of a measured data rate value (in units of bps). In addition, in another embodiment of the disclosure, information on the data rate may be divided into specific intervals from 0 to a maximum data rate value and may be included in the message including the band combination information usable by the MN in the form of an indicator indicating each divided duration. In an embodiment of the disclosure, the latency may be measured for each band combination, and may include information on the latency which occurs when the band combination is used.
In operation 620, the MN may receive a response message including the determined band combination. The response message may include information on a band combination selected by the SN. The SN may determine a band combination to be used based on a message including the received band combination information.
Although not shown in
Referring to
The information on the data rate for each band combination may include information on a latency and the data rate for each band combination of the MN. The information on the data rate for each band combination may be included in the message in the form of an index, an ID, and a weight.
The information on the data rate for each band combination of the MN may be present for each of at least one band combination usable by the MN. For example, if the number of band combinations usable by the MN is k, the number of pieces of information on a data rate may correspond to k. In order to transmit the information on the data rate for each band combination, the MN may measure a data rate of the MCG for each band combination. The data rate may be measured based on Equation 1 when the MN is a gNB, and may be measured based on Equation 2 when the MN is an eNB.
For example, the band combination information may be included in the RRC message in the form as follows.
In Table 3 above, allowedBC-ListMRDC means a list of band combinations usable by the MN to operate the MR-DC. allowedBC-ListMRDC may be constructed of BandCombinationInfoList, and may have a form of a BandCombinationInfo. bandCombinationIndex means a band combination indicator.
In an embodiment of the disclosure, information on a data rate of the MCG may be included in the message to be transmitted by the MN to the SN in operation 710. The information on the data rate of the MCG may be present for each band combination. By receiving a message including the information on the data rate of the MCG, the SN may consider up to the data rate of the MCG for each band combination and thus select a best band combination considering a total amount of the MCG data rate and SCG data rate.
For example, the information on the data rate of the MCG may be included in the RRC message in the following form.
In Table 4 above, allowedBC-ListMRDC means a list of band combinations usable by the MN to operate the MR-DC. allowedBC-ListMRDC may be constructed of BandCombinationInfoList, and may have a form of a sequence of BandCombinationInfo. bandCombinationIndex means a band combination indicator.
bandCombinationMCGInfoList means a list of information related to communication performance of the MCG for each band combination included in the band combination usable by the MN. The aforementioned information on the data rate for each band combination may include information (expectedDataRate) on the data rate for each band combination and information (expectedLatency) on an expected latency of the MCG for each band combination. The data rate may be measured for each band combination, and may be measured based on Equation 1 or Equation 2.
In an embodiment of the disclosure, an expected data rate may be included in a message including the band combination information usable by the MN in the form of a measured data rate value (in units of bps). In addition, in another embodiment of the disclosure, information on the data rate may be divided into specific intervals from 0 to a maximum data rate value and may be included in the message including the band combination information usable by the MN in the form of an indicator indicating each divided duration.
In an embodiment of the disclosure, an expected latency may be measured for each band combination, and may include information on the latency which occurs when the band combination is used.
In operation 720, the SN may determine a band combination. The SN may determine the band combination, based on a message including received band combination information. In order to select the band combination, the SN may measure an expected data rate for each band combination of an SCG. The expected data rate may be measured based on Equation 1 or Equation 2 described above.
The SN may determine a best band combination, based on the expected data rate of the SCG for each band combination and the expected data rate for each band combination of the MCG included in the received band combination information. The SN may select a band combination expected to have the highest total sum of the data rate of the SCG and the data rate of the MCG as the best band combination. For example, even if there is a band combination (e.g., a band combination 1) in which an expected data rate of the SCG is measured to be the highest, when there is another band combination (e.g., a band combination 2) in which a total sum of the data rate of the MCG and the data rate of the SCG is the highest, the SN may select not the band combination 1 but the band combination 2. By selecting a band combination considering not only the data rate of the SCG but also the data rate of the MCG, it is possible to select a best band combination in DC operations.
In operation 730, the SN may transmit the determined band combination to the MN. The SN may transmit a response message to the MN by including information on the determined band combination to the response message.
A secondary node (SN) apparatus according to an embodiment of the disclosure described above may include a transceiver and a processor operatively coupled to the transceiver. The processor may be configured to receive a request message from a master node (MN), wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of a master cell group (MCG) for each of the at least one band combination, identify a band combination from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of a secondary cell group (SCG), and transmit a response message including information indicating the identified band combination to the MN.
In an embodiment of the disclosure, in order to identify the band combination from among the at least one band combination, the processor may be configured to select a band combination in which a sum of the first data rate and the second data rate is the highest from among the at least one band combination.
In an embodiment of the disclosure, the request message may be received from the MN through radio resource control (RRC) signaling. The SN may use new radio (NR) or long-term evolution (LTE) as a radio access technology (RAT). The MN may use the NR or the LTE as the RAT.
In an embodiment of the disclosure, in the first data rate information, the MCG may include latency information on the at least one band combination.
In an embodiment of the disclosure, in order to identify the band combination from among the at least one band combination, the processor may be configured to select the band combination, based on the latency information and quality of service (QoS) of a service to be provided to a terminal.
An MN apparatus according to an embodiment of the disclosure described above may include a transceiver, and a processor operatively coupled to the transceiver. The processor may be configured to transmit a request message to an SN, wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of an MCG for each of the at least one band combination, and receive a response message including information indicating the identified band combination from the SN. The band combination may be identified from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of an SCG.
In an embodiment of the disclosure, a band combination in which a sum of the first data rate and the second data rate is the highest from among the at least one band combination may be selected as the band combination.
In an embodiment of the disclosure, the request message may be transmitted from the SN through RRC signaling. The SN may use NR or LTE as an RAT. The MN may use the NR or the LTE as the RAT.
In an embodiment of the disclosure, in the first data rate information, the MCG may include latency information on the at least one band combination.
In an embodiment of the disclosure, in the first data rate information, the MCG may include latency information on the at least one band combination.
In an embodiment of the disclosure, the band combination may be selected based on the latency information and QoS of a service to be provided to a terminal.
A method of operating an SN according to an embodiment of the disclosure described above may include receiving a request message from an MN, wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of an MCG for each of the at least one band combination, identifying a band combination from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of an SCG, and transmitting a response message including information indicating the identified band combination to the MN.
In an embodiment of the disclosure, the identifying of the band combination from among the at least one band combination may include selecting a band combination in which a sum of the first data rate and the second data rate is the highest from among the at least one band combination.
In an embodiment of the disclosure, the request message may be received from the MN through RRC signaling. The SN may use NR or LTE as an RAT. The MN may use the NR or the LTE as the RAT.
In an embodiment of the disclosure, in the first data rate information, the MCG may include latency information on the at least one band combination.
In an embodiment of the disclosure, the identifying of the band combination from among the at least one band combination may include selecting a band combination, based on the latency information and QoS of a service to be provided to a terminal.
A method of operating an MN apparatus according to an embodiment of the disclosure described above may include transmitting a request message to an SN, wherein the request message includes information indicating at least one band combination and first data rate information on a data rate of an MCG for each of the at least one band combination, and receiving a response message including information indicating the identified band combination from the SN. The band combination may be identified from among the at least one band combination, based on the first data rate information and second data rate information on a data rate of an SCG.
In an embodiment of the disclosure, a band combination in which a sum of the first data rate and the second data rate is the highest from among the at least one band combination may be selected as the band combination.
In an embodiment of the disclosure, the request message may be transmitted from the SN through RRC signaling. The SN may use NR or LTE as an RAT. The MN may use the NR or the LTE as the RAT.
In an embodiment of the disclosure, in the first data rate information, the MCG may include latency information on the at least one band combination.
In an embodiment of the disclosure, in the first data rate information, the MCG may include latency information on the at least one band combination.
In an embodiment of the disclosure, the band combination may be selected based on the latency information and QoS of a service to be provided to a terminal.
Methods based on the embodiments disclosed in the claims and/or specification of the disclosure may be implemented in hardware, software, or a combination of both. When implemented in software, computer readable recording medium for storing one or more programs (i.e., software modules) may be provided. The one or more programs stored in the computer readable recording medium are configured for execution performed by one or more processors in the electronic device. The one or more programs include instructions for allowing the electronic device to execute the methods based on the embodiments disclosed in the claims and/or specification of the disclosure.
The program (i.e., the software module or software) may be stored in a random access memory, a non-volatile memory including a flash memory, a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage devices, and a magnetic cassette. Alternatively, the program may be stored in a memory configured in combination of all or some of these storage media. In addition, the configured memory may be plural in number.
Further, the program may be stored in an attachable storage device capable of accessing the electronic device through a communication network, such as the Internet, an Intranet, a local area network (LAN), a wide LAN (WLAN), or a storage area network (SAN) or a communication network configured by combining the networks. The storage device may have access to a device for performing an embodiment of the disclosure via an external port. In addition, an additional storage device on a communication network may have access to the device for performing the embodiment of the disclosure.
In the aforementioned specific embodiments of the disclosure, a component included in the disclosure is expressed in a singular or plural form according to the specific embodiment proposed herein. However, the singular or plural expression is selected properly for a situation proposed for the convenience of explanation, and thus the various embodiments of the disclosure are not limited to a single or a plurality of components. Therefore, a component expressed in a plural form may also be expressed in a singular form, or vice versa.
While the disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0040528 | Mar 2021 | KR | national |
This application is a continuation application, claiming priority under § 365(c), of an International application No. PCT/KR2022/004078, filed on Mar. 23, 2022, which is based on and claims the benefit of a Korean patent application number 10-2021-0040528, filed on Mar. 29, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2022/004078 | Mar 2022 | US |
| Child | 18462835 | US |
