Method for communicating control information

Abstract

The present invention relates to a communication method that comprises transmitting, at a first transmission interval (TTI), control information (DCI) comprising a first band portion indicator (BWP1) for transmitting data associated with a first slice via the first band portion (BWP1), a second band portion indicator (BWP2) for transmitting or receiving, via this second band portion (BWP2), data associated with a second slice and a first switching time indicator (J1) for switching active band portion between the first band portion (BWP1) and the second band portion (BWP2).

Description

[0001] DESCRIPTION

[0002] TITLE: Method for communicating control information

[0003] Field of invention

[0004] The present invention relates to the field of digital communications. Within this field, the invention relates more particularly to the use of control information within a telecommunications system.

[0005] The invention applies in particular, but not exclusively, to the transmission of control information in a mobile network, for example of the 5G type and following as specified by 3GPP and / or O-RAN.

[0006] Prior art

[0007] The so-called 5G network includes significant developments compared to the previous generation, known as 4G.

[0008] Among these, network slicing should be noted. This slicing was introduced to meet the requirements of the services that the 5G network must provide. These services include highly reliable, low-latency services called URLLC (Ultra Reliable and Low Latency Communications), high-speed services called eMBB (enhance Mobile Broadband), and high-node density services called mMTC (massive Machine Type Communications), as well as V2X (Vehicle to Everything) and HMTC (High Performance MTC) services. Slicing allows the network to be partitioned into logical slices that are isolated from each other. Each slice is dedicated to a service and benefits from radio resources. A slice is identified by its identifier, S-NSSAI (Single Network Slice Selection Assistance Information). A terminal, UE (User Equipment), can be associated with eight slices simultaneously.The terminal connected to the network transmits the S-NSSAI identifier of the slice / service it wishes to access.

[0009] Regarding the evolution of numerology, multiple subcarrier spacings, SCS (SubCarrier Spacing), have been introduced, as shown in [Table 1] established from Table 4.2-1 of the TS38.211 V15.10.0 specification. [Table 1] The subcarrier spacing, SCS, is flexible. Increasing the numerology, i.e., the spacing, SCS, allows for a reduction in the OFDM symbol duration as well as the Time Transmission Interval, TTI, and thus for reducing latency for very delay-intensive services.

[0010] Transmissions between a transmitter and a receiver are organized into frames, each comprising sub-frames of duration depending on the numerology, for example 10 sub-frames of 1 ms each. The number of slots per sub-frame is a function of the numerology, the choice p of the spacing between sub-carriers, SCS, and each slot comprises a number N y°n bconsecutive OFDM symbols as indicated in paragraph 4.3.2 of TS 38.211 V17.4.0. Concomitantly with the evolution of numerology, the concept of band part, BWP (Bandwidth Part), was introduced to allow the implementation of the different numerologies. A band part, BWP, is a set of contiguous physical resource blocks, PRB (Physical Resource Block) associated with a numerology. A physical resource block, PRB, is the smallest radio resource that can be allocated to a terminal, UE. The terminal, UE, scans the radio resources allocated to it in a band part, BWP, to receive the data intended for it in the downstream direction, DL (Down Link). The network can configure the terminal, UE, with four band parts, BWP, in the downlink direction and the same in the uplink direction, UL (Uplink) but only one band part, BWP, is active at a given time in the downlink direction, DL, and only one in the uplink direction, UL.When the terminal, UE, requires a new service, for example by switching from an eMBB service to a URLLC service, the active band part, BWP, is not necessarily the best suited to the URLLC service. A switchover (switching) can then take place to another band part, typically a band part associated with a higher numerology to reduce the delay for this very latency-demanding service. The band part switching (BWP switching) mechanism makes it possible to ensure that the active band part, BWP, is the best suited to the requirements of the current service.

[0011] The fastest way of several possibilities to perform a failover is Downlink Control Information (DCI)-based BWP switching.

[0012] The DCI can take several formats, from format 0_0 to format 4_2 as indicated in [table 2] established from table 7.3.1-1 of the TS 38.212 V17.4.0 specification, associated with different orders for the downstream or upstream direction, [table 2]

[0013] The control information, DCI, is transmitted in a control channel, PDCCH (Physical Downlink Control Channel) that the terminal receives at the same recurrence as the data intended for it.

[0014] The DCI includes a lot of control information. For the 0_l and 1_1 formats associated respectively with an uplink and downlink scheduling without reduced signaling (non-reduced overhead format) to dynamically allocate time and frequency resources for the data channel, PDSCH or PUSCH, the DCI includes among other information: MCS (Modulation and Coding Scheme), BWP indicator, Frequency domain resource assignment, Time domain resource assignment (K0 / K2), etc., and additionally for the 1_1 format: PDSCH-to-HARQ-ACK return timing indicator (Kl).

[0015] The decoding of control information, DCI, provides the terminal in particular with the temporal and frequency location of the radio resources to be scanned.

[0016] The "time domain resource" field allows the terminal, UE, to determine the KO value for a DCI format 1_1, in accordance with clauses 5.1.2.1 and 5.1.2.1.1 of the TS38.214 V15.16.0 specification and to determine the K2 value for a DCI format 0_l, in accordance with clauses 6.1.2.1 and 6.1.2.1.1 of the TS38.214 V15.16.0 specification.

[0017] The "PDSCH-to-HARQ-ACK return timing indicator" field of the DCI format 1_1 allows the terminal, UE, to determine the value of Kl in accordance with paragraph 9.2.3 and Table 9.2.3-1 of the TS38.213 V15.15.0 specification.

[0018] KO gives the offset in number of slots between the reception of the control information, DCI, and the scheduling of the radio resources in the downlink for the transmission, via the data channel, PDSCH, of the data intended for the UE terminal. Kl gives the offset in number of slots between the scheduling of the radio resources for the downlink, PDSCH, and the ACK / NACK for the same UE terminal. Thus, if the DCI format is 1_1, the terminal determines that the data transmitted in the downlink channel PDSCH and intended for it are scheduled KO slots after the reception of the control information, DCI, and that it must transmit in the uplink channel PUSCH an ACK / NACK after Kl slots of the reception of the control information, DCI.

[0019] K2 gives the offset in number of slots between the reception of the control information, DCI, and the scheduling of radio resources for the uplink, PUSCH. Thus, if the format of DCI is 0_l, the terminal determines that the data it must transmit in the uplink channel, PUSCH, is scheduled K2 slots after the reception of the control information, DCI.

[0020] According to the example illustrated in Figure 1, the control channel, PDCCH, which includes the control information, DCI, corresponding to the format 1_1 is received at slot 0. KO gives the offset in number of slots, three according to the example, to determine the slot, number three according to the example, which contains the data channel, PDSCH, with the data intended for the terminal. Kl gives the offset in number of slots, five according to the illustration, relative to the slot containing the data which determines the slot, number 8 according to the example, during which the terminal must acknowledge receipt, ACK / NACK, of the data transported in the slot number three.

[0021] According to the example illustrated in Figure 2, the control channel, PDCCH, which includes the control information, DCI, corresponding to the format 0_l is received at slot 0. K2 gives the offset in number of slots, three according to the example, from the reception of the control information, DCI, so that the terminal orders the data that it has to transmit on the uplink channel, PUSCH, at slot 3 according to the example.

[0022] The “frequency domain resource” field of the DCI allows the terminal, UE, to identify the block resources allocated to it in the part of the band identified by the BWP indicator for the transmission of data intended for it.

[0023] When the terminal decodes the received DCI, the BWP indicator tells it which bandpart, BWP, should be activated. If this BWP indicator has changed, the terminal must switch between bands within a certain time in accordance with the DCI-based BWP switching mechanism since the DCI determines the bandpart, BWP, to be scanned.

[0024] The BWP bandpart switching delay is given in [Table 3] derived from Table 8.6.2-1 of TS38.133 V15.20.0. [Table 3]

[0025] A terminal, UE, connected to the network and associated with several slices receives data relating to these different slices. In a known manner, the terminal, UE, scans the same part of the band for these different services to receive its data. This mechanism is not optimal when the services have very different requirements, for example low latency and high reliability for a URLLC service and high throughput for an eMBB service. Indeed, achieving these requirements requires different numerologies which are not compatible with the same part of the band.

[0026] Alternatively, illustrated by Figures 3 and 4, it is known to send control information, DCI, comprising a different band part indicator, BWP1, BWP2, before each transmission associated with a different service, Servi, Serv2, so that the terminal switches active band between transmissions associated with different services. Figures 3 and 4 illustrate the switching between active bands, BWP1, BWP2, respectively in the downlink direction, DL DCI, and in the uplink direction, UL DCI.

[0027] This mode is time-consuming since the terminal must wait for a DCI or several slots (several milliseconds) before being able to switch active bands and receive its data as illustrated in Figure 5. According to this illustration, the terminal, UE, receives data on slice 1 in band part BWP 1. It must wait a time Atl to receive a new DCI with the indication of a new band part BWP2 before being able to switch active band part, from BWP1 to BWP2, and receive data associated with slice 2 on the PRBs Slice2 radio resources. Before the switch, the terminal cannot receive data from this slice 2 on the PRBs Slice2 radio resources associated with it.Similarly, to switch back to the band part BWP1, the terminal, UE, must wait a time At2 to receive a new DCI with the indication of the band part BWP1 before being able to switch the active band part, from BWP2 to BWP1, and receive data associated with the slice (slice 12) on the PRBs Slicel radio resources. Before the switch, the terminal cannot receive data from this slice 1 on the PRBs Slicel radio resources associated with it. The base station, BS, determines the scheduling of the terminal with the sending of DCIs to Atl, At2, to try to respect performance, KPI for each slice. Such a mechanism is not compatible with a URLLC service which tolerates a maximum latency of one millisecond.

[0028] Main features of the invention

[0029] The present invention relates to a communication method which comprises:

[0030] - transmitting at a first transmission interval control information comprising a first band portion indicator for transmitting data associated with a first slice via the first band portion, such as:

[0031] - the control information transmitted at the first transmission interval further comprises a second band portion indicator for transmitting or receiving, via this second band portion, data associated with a second slot and a first switching time indicator for switching the active band portion between the first band portion and the second band portion.

[0032] The invention further relates to a communication method which comprises:

[0033] - receiving at a first transmission interval control information comprising a first band part indicator for receiving data associated with a first slice via the first band part, such that: the control information received at the first transmission interval further comprises a second band part indicator for receiving or transmitting, via this second band part, data associated with a second slice and a first switching time indicator for switching the active band part between the first band part and the second band part.

[0034] The invention further relates to a telecommunications device comprising at least one transmitter and one receiver, the device is adapted to: receive, at a first transmission interval, control information comprising a first band part indicator, a second band part indicator and a first switching time indicator for switching the active band part between the first band part and the second band part, receive or transmit data associated with a first slot via the first band part and, after switching the active band part, data associated with a second slot via the second band part.

[0035] The invention further relates to a telecommunications device comprising at least one transmitter and one receiver, the device is adapted to: transmit at a first transmission interval control information comprising a first band part indicator, a second band part indicator and a first switching time indicator for switching the active band part between the first band part and the second band part, transmit data associated with a first slice via the first band part and, after switching the active band part, data associated with a second slice via the second band part.

[0036] The invention further relates to a telecommunications system comprising a base station and a terminal for implementing a communication method according to the invention. The transmission of control information allows the scheduling of one or more terminals. The entity in charge of this transmission may be a base station, a base station controller or a specific entity called a scheduler. The terminal(s) to be scheduled are connected to a core network via an access network to which the scheduler belongs. The terminal(s) are connected to different services or slots to which QoS flows correspond. The scheduler determines for a given terminal the values ​​of the switching time indicators J 1 , J2, . . ., depending in particular on the qualities associated with the QoS flows and the radio performance of the transmission channel between the access network and this terminal to ensure a switching delay between active bands which is compatible with the latency requirements of the services to which the terminal is connected. By simultaneously transmitting two band part indicators, of which only one is active at a given transmission interval, and a time indicator of the transmission interval where the active band part switching must take place, the method can shorten the latency time compared to a mechanism which requires waiting for a new transmission of control information to trigger an active band part switching.

[0037] According to one embodiment, the method further comprises:

[0038] - before the transmission of the control information, reception of an identifier of the first tranche and an identifier of the second tranche for the association of the same terminal with these first and second tranches.

[0039] According to one embodiment, the control information transmitted at the first transmission interval further comprises a first time offset indicator after the first transmission interval for transmitting data associated with the first slot via the first band portion and the active band portion switchover occurs after the scheduling of the data associated with the first slot and transmitted via the first band portion. In some embodiments, said first, respectively second, switching time indicator is a time index of a first, respectively second, transmission slot.

[0040] According to one embodiment, the method further comprises: before receiving the control information, transmitting an identifier of the first tranche and an identifier of the second tranche for the association of the same terminal with the first and second tranches.

[0041] According to one embodiment, the first band part and the second band part respectively benefit from different numerologies.

[0042] According to one embodiment, the control information is carried by the same control channel.

[0043] According to one embodiment, the data associated with the first slice and the data associated with the second slice are received or transmitted in the same shared channel of received data or the same shared channel of transmitted data.

[0044] According to one embodiment, the data associated with the first slice and the data associated with the second slice are associated with services of different types.

[0045] According to one embodiment, the data associated with one of the slices is associated with a service of a type requiring high reliability and low latency, i.e., URLLC.

[0046] The features presented in isolation in the present application in connection with certain embodiments of the method of the present application can be combined with each other according to other embodiments of the present method.

[0047] The optional features presented above within the framework of the communication method may optionally be applied to the devices, the software application and the support memory of the software application according to the invention.

[0048] List of figures

[0049] Other characteristics and advantages of the invention will appear more clearly on reading the following description of embodiments, given as simple illustrative and non-limiting examples, and the appended drawings, among which:

[0050] [Fig 1] Figure 1 is a diagram illustrating the scheduling of a terminal for a received DCI of 1_1 format described with respect to the prior art,

[0051] [Fig 2] Figure 2 is a diagram illustrating the scheduling of a terminal for a received DCI of format 0_l described with respect to the prior art,

[0052] [Fig 3] Figure 3 is a scheduling diagram illustrating the switching of a terminal between active bands in the downstream direction, DL DCI, described with respect to the prior art, [Fig 4] Figure 4 is a scheduling diagram illustrating the switching of a terminal between active bands in the upstream direction, UL DCI, described with respect to the prior art,

[0053] [Fig 5] Figure 5 is a diagram illustrating an implementation of an example of scheduling according to the prior art of a terminal connected via a base station to two services, [Fig 6] Figure 6 is a diagram of a telecommunications network,

[0054] [Fig 7] Figure 7 is a protocol exchange diagram,

[0055] [Fig 8] Figure 8 is a diagram of a time-frequency grid corresponding to a time and frequency division of the radio resources of the transmission channel,

[0056] [Fig 9] Figure 9 is a diagram illustrating an implementation by a suitable terminal of an embodiment of a method according to the invention,

[0057] [Fig 10] Figure 10 is a diagram illustrating an implementation of an example of scheduling according to the invention of a terminal connected via a base station to two services,

[0058] [Fig 11] Figure 11 is a diagram of an embodiment of a base station according to the invention,

[0059] [Fig 12] Figure 12 is a diagram of an embodiment of a terminal according to the invention, [Fig 13] Figure 13 is a diagram of a telecommunications network in an O-RAN context. Description of particular embodiments

[0060] The invention is placed in the context of a telecommunications network illustrated by Figure 6 with a service-oriented architecture such as the 5G network. Thus, the network is divided into slices, separate and independent from each other seen from the terminal, each slice is a logical entity associated with a service, for example URLLC, eMBB, etc. A slice is identified by its identifier, S -NS S AI.

[0061] The SYS telecommunications network comprises a CN core network and an access network with at least one BS base station, called gNB in ​​the 5G network. The base station can be implemented with a single piece of hardware or distributed across several pieces of hardware. The core network comprises a central logical entity called AMF (Access and Mobility Function). The AMF is responsible, among other things, for control signaling between the core network and the TAL terminals. The functionalities between the AMF and a TAL terminal are sometimes called NAS (Non-Access Stratum) as opposed to the functionalities called AS (Access Stratum) between the access network and a terminal.

[0062] Figure 7 schematically illustrates certain protocol exchanges for the implementation of a method 11 according to the invention. Once it has detected a cell which is associated with a base station, the terminal camps on this cell and then accesses the cell by following a protocol called RACH. In a non-limiting manner, the cell is confused with the base station.

[0063] During an initial attachment procedure, the terminal makes a registration request 1 (RRC setup) by giving a list of S-NSSAI identifiers of services that it wants to request (“requested NSSAI”). The AMF finalizes 2 the registration by providing the terminal in a message (“allowed NSSAI”) the list of S-NSSAI identifiers of the services, i.e., the slots that it is authorized to request. According to the 5G specifications, the number of identifiers authorized for a terminal is limited to eight. The base station is informed 2 of the list of S-NSSAI identifiers authorized for the terminal.

[0064] A similar mechanism occurs during a reconfiguration request called “RRC reconfiguration” during which an update is carried out to the list of S-NSSAI identifiers authorized for the terminal.

[0065] The specifications of a 5G network distinguish several states for a terminal: "RRC_idle", RRC inactive and RRC connected. In the RRC connected state, or more commonly called connected, the connection is established between the terminal and the core network, data exchange is possible between the base station and the terminal.

[0066] The establishment of a terminal connection is done according to a protocol that can be based on functionalities of the NAS control plane, between the terminal and the AMF, and on functionalities of the radio resource control plane called RRC (Radio Resource Control). The establishment of a connection comprises the establishment of at least one PDU data session with an S-NSSAI identifier selected by the terminal and transmitted 3 to the base station. In connection 4 with the AMF, the base station returns 5 to the terminal the accepted S-NSSAI identifier. For a connected terminal, there are one or more PDU sessions, each with one or more QoS flows and data radio bearers. The IP packets are mapped by the core network onto the QoS flows according to the QoS requirements. And the QoS flows are mapped onto the data radio bearers by the access network.The terminal can observe the QoS Flow Identifiers (QFIs) associated with packets received from downstream flows to determine which IP flow is mapped to which QoS flow and which data radio bearer and to use a similar mapping for the upstream direction. When the base station informs the terminal of the acceptance of the PDU session establishment, it returns a message to the terminal that includes the accepted slice identifier S-NSSAI as well as information such as the flow QFI identifier, the quality (QoS) requirement of the flow, 5QI (5G Quality Indicator) which takes into account the maximum supported delay, the priority for the flow, the type of service (video, voice, etc.). A PDU session can contain several QoS flows. Each QoS flow can carry several service data flows (SDFs), called traffic flows, provided that they meet the same requirements.A slice can carry multiple QoS flows but a QoS flow can only be carried by a single slice.

[0067] Transmissions between the base station of the access network and the terminal are carried out in a channel that is shared between the different terminals connected to the core network. In other words, the time-frequency resources of the transmission channel are dynamically shared between users in both TDD (Time Division Duplex) and FDD (Frequency Division Duplex) modes. Transmissions are scheduled in both the upstream and downstream directions and follow scheduling decisions orchestrated according to a time cadence, typically by slot, a slot during a transmission time interval, TTI (Transmission Time Interval) according to the technical specifications of the 5G network. When the access network implements multi-carrier modulation such as OFDM, the radio resources of the transmission channel are represented by a time-frequency grid illustrated in Figure 8.Each element of the grid is called a resource element, RE (Resource Element) and is identified by a time index l and a frequency index k. A multicarrier symbol is identified by a time index l.

[0068] Scheduling a terminal consists of assigning it resource elements from this grid, generally one or more blocks, PRB (Physical Resource Blocks) of resource elements identified for example by a number of contiguous resource blocks, a start time interval and a first subcarrier when the blocks are contiguous.

[0069] Given that the frequency spectrum is very wide, the 5G network specifications introduced the concept of band part, B WP. A band part, BWP, is a set of contiguous blocks of physical resources, PRB (Physical Resource Block) associated with a numerology. Thus, the scheduling of a terminal is accompanied by the indication of the active band part which specifies the frequency zone where the resource elements allocated to the terminal are located and therefore that the terminal must scan in the downlink for reception and that the terminal uses in the uplink to transmit. There can be two different active band indications, one for the downlink, one for the uplink.

[0070] Scheduling information is transmitted 6 by the base station to the terminal via a control channel. According to the 5G network specifications this control information is included in the DCI and carried by the PDCCH channel.

[0071] The scheduling may take into account channel quality information (CSI Channel State Information, CQI Channel Quality Indicator) between the base station and the terminal to allocate more or less resource elements to a scheduled terminal. According to the invention, the scheduling takes into account the network slicing and more particularly the fact that the terminal may simultaneously request several services associated with different slices, for example a URLLC service and an eMBB service, and which may have very different latency and / or throughput requirements. The NSSAI set designates the identifiers of the slices required by a terminal.

[0072] Thus, during a transmission at a first transmission interval of control information, the latter comprises a first band part indicator BWP1 for a transmission of data associated with a first slice via this first active band part BWP1. And, according to the invention, the control information transmitted at the first transmission interval further comprises at least: a second band part indicator BWP2 for a transmission, i.e., for transmitting or receiving, via this second band part BWP2, of data associated with a second slice and a first switching time indicator J1 for switching the active band part between the first band part BWP1 and the second band part BWP2.

[0073] An implementation by a suitable terminal of an embodiment of a method according to the invention is illustrated schematically by Figure 9. The terminal is suitable in that it implements the reception method 21 according to the invention, according to which the control information, received 211 at a first transmission interval via a dedicated control channel, comprises 212: a first band part indicator BWP1 for a transmission of data associated with a first slice via this first active band part BWP1 and furthermore at least: a second band part indicator BWP2 for a transmission, i.e., for transmitting or receiving, via this second band part BWP2, of data associated with a second slice and a first switching time indicator J1 for switching the active band part between the first band part BWP1 and the second band part BWP2.

[0074] In a non-limiting manner, the value of the switching time indicator J 1 can be determined in number of transmission intervals (slots) from the transmission interval (slot) of reception of the control information. This value can just as well be determined in a relative manner with respect to an event dawn, for example a reception of data or a transmission of data.

[0075] Of course, the control information transmitted at the first transmission interval may comprise more than two band part indicators and / or more than one switching time indicator to successively switch active band part without waiting for a new transmission of control information, each band part being associated with a slice of identifier S-NSSAI.

[0076] According to one embodiment, the control information transmitted at the first transmission interval may further comprise a second switching time indicator J2 for switching the active band part between the second band part BWP2 and the first band part BWP1, with J2>J1.

[0077] The base station can determine the number of band part indicators and switching time indicators to be transmitted in the same transmission interval based on different parameters taken from at least: the number of services (slots) to which the terminal is connected, the number of QoS flows and the associated 5QI qualities, the type of traffic flow. The base station can also be based on performance indicators such as indications on the quality of the radio link (CSI, CQI, etc.) between the terminal and the base station. The base station can also request from the terminal feedback of indicators on the received signal level, on the modulation and coding scheme (MCS) that it recommends, on a signal-to-noise ratio (SNR), on a signal-to-noise plus interference ratio (SNIR).

[0078] Using this various information, parameters and indicators, the base station can optionally perform traffic predictions by slot to determine the control information to communicate to the terminal in a dedicated control channel.

[0079] The base station can determine the values ​​of the switching time indicators Jl, J2, . . . , depending in particular on the 5QI qualities associated with the QoS flows and the radio performances to ensure a switching delay between active bands which is compatible with the latency requirements of the services to which the terminal is connected.

[0080] To determine what control information to transmit, the base station can establish a matrix of the terminal's QoS flows.

[0081] The control information transmitted at the first transmission interval may further include a first time offset indicator KO after the first transmission interval for receiving data on the first band portion BWP1.

[0082] The control information transmitted at the first transmission interval may further comprise a second time offset indicator K1 which gives the offset in number of slots between the scheduling of the radio resources for the downlink, PDSCH, and the ACK / NACK upload for the same terminal UE. The switchover to J1 of the active band part may then occur after the scheduling of the data associated with the first slice and transmitted via the first band part BWP1.

[0083] In the case of scheduling a terminal for an uplink transmission, the control information transmitted at the first transmission interval may further comprise a first time offset indicator K2 after the first transmission interval for the data transmission, via the first band part BWP1, in the uplink. K2 gives the offset in number of slots between the reception of the control information, DCI, and the scheduling of the radio resources for the uplink, PUSCH.

[0084] Figure 10 schematically illustrates an implementation of an example of scheduling according to the invention of a terminal connected via a base station to two services, one of which 1 er eMBB service (slice) associated with a first part of BWP1 band and a 2 nd URLLC service (slice) associated with a second part of BWP2 band. To ensure low latency at 2 ndURLLC service, it has a higher priority than 1 er eMBB service and a part of BWP2 band different from the part of BWP1 band allocated to 1 er eMBB service.

[0085] According to this illustrated example, the base station maintains an up-to-date flow matrix and associated parameters that they collect. At time t = T0, the base station transmits via a control channel, PDCCH, dedicated to the terminal, a DCI based on this matrix which comprises a first band part indicator BWP2 with a switching time indicator J1 = T0 to switch the active band part immediately, i.e. during the current slot with time index t = T0. The terminal which receives the dedicated control channel and which had the active band part BWP1 before T0, switches at T0 to the band part BWP2 which becomes the active part. The DCI transmitted at T0 may further comprise a second band part indicator BWP1 with a switching time indicator J2 = T3 to switch the active band part to the slot with time index t = T3. After switching the active band from BWP1 to BWP2, the terminal receives data from the 2 ndservice on radio resources, PRB Slice 2, part of the active band part BWP2. After switching the active band from BWP2 to BWP1, the terminal receives data from the 1 at two different times er service on radio resources, PRB Slice 1, part of the active band part BWP1.

[0086] At time t = Tx, the base station transmits via the dedicated control channel, PDCCH, a DCI based on the matrix and which comprises a first band part indicator BWP2 with a first switching time indicator J 1 for switching the active band part immediately, i.e. during the current slot with time index t = Tx and a second switching time indicator J2 for switching the active band part to the slot with time index t = Tx + y = z. The terminal which had the active band part BWP1 before Tx switches at Tx to the active band part BWP2. The DCI transmitted at Tx further comprises a second band part indicator BWP1 with a switching time indicator J 3 = Tx + y for switching the active band part to the slot with time index t = Tx + y.

[0087] Of course, the terminal can have n > 2 active services and the DCI contain more than two BWP2 bandpart indicators and more than one failover time indicator.

[0088] The method can make it possible to switch active band parts more efficiently by transmitting in advance in the same dedicated control channel, for example PDCCH / DCI, one or more switching time indicators for switching active band parts instead of waiting for a new dedicated control channel, for example PDCCH / DCI. The method can therefore contribute to a reduction in latency and can therefore make it possible to ensure the expected quality of a URLLC type service.

[0089] This method has the advantage of being compatible with terminals since it does not require the terminal to simultaneously activate two parts of the band with different numerologies. Indeed, the only active part of the band at a given time according to the method is associated with a single numerology and therefore compatible with the multicarrier processing specified in the 3GPP 5G system technical specifications, up to at least release 17.

[0090] An implementation of the method that complies with the technical specifications of a 5G network only requires adding a few fields to the dedicated control channel, PDCCH / DCI, but does not require changing the size of the DCI since it includes variable-sized fields whose size can be adjusted.

[0091] The implementation previously detailed is not limiting, at the base station level, to the number of terminals connected via this base station and taken into account by the method. The latter can be implemented with several terminals and, for each terminal, the base station determines the dedicated control channel, PDCCH / DCI, to be transmitted in the same way as for a single terminal.

[0092] Figure 11 is a schematic diagram of the simplified structure of an embodiment of a base station BS according to an embodiment of the invention.

[0093] The base station BS comprises at least one microprocessor pP_BS whose operation is controlled by the execution of a program whose instructions allow the implementation of a method according to the invention, a memory MEM_BS, a transmitter EM_BS and a receiver RE_BS which are connected to each other by means of, for example, a bus. Of course, the constituent elements of the base station BS can be connected by means of a connection other than a bus. The microprocessor pP_BS controls the operations of the base station BS. The storage unit MEM_BS stores at least the program for the implementation of the method according to an embodiment of the invention to be executed by the processor pP_BS, and various data, such as parameters and / or indicators, NSSAI, 5QI, associated with a terminal, UE, used for calculations carried out by the microprocessor pP, intermediate data of calculations carried out by the microprocessor pP, etc.The pP_BS microprocessor can be formed by any known and suitable hardware or software, or by a combination of hardware and software. For example, the pP_BS microprocessor can be formed by dedicated hardware such as a processing circuit, or by a programmable processing unit such as a central processing unit (Central Processing Unit in English) which executes a program stored in a memory thereof.

[0094] MEM_BS memory may be formed by any suitable means capable of storing the program(s) and data in a manner readable by a microprocessor. Examples of MEM_BS memory include non-transitory storage media such as semiconductor memory devices, and magnetic, optical, or magneto-optical recording media loaded into a read and write unit controlled by the microprocessor.

[0095] During initialization, the program code instructions are, for example, loaded into a buffer memory before being executed by the pP_BS microprocessor. The pP_BS microprocessor controls the various components of the BS base station.

[0096] Thus, by executing the instructions, the microprocessor pP_BS allows the base station BS to implement the method according to an embodiment of the invention, which comprises:

[0097] - transmission, implemented by the transmitter EM_BS, at a first transmission interval, TTI, of control information, DCI, comprising a first band part indicator, BWP1, for transmitting data associated with a first slice via the first band part, BWP1, such that:

[0098] - the control information, DCI, transmitted at the first transmission interval, TTI, further comprises a second band part indicator, BWP2, for transmitting by the transmitter EM BS or receiving by the receiver BS_RE, via this second band part, BWP2, data associated with a second slice and a first switching time indicator, J 1 , for switching the active band part between the first band part, BWP1, and the second band part, BWP2.

[0099] The transmitter EM_BS may transmit pilot signals, for example DMRS, for the terminal to determine the quality of the downlink channel. The receiver RE_BS may receive pilot signals, for example SRS, from a terminal to determine the quality of the uplink channel and, by reciprocity, deduce a quality of the downlink channel therefrom. Other techniques well known to those skilled in the art are possible for channel estimation, whether uplink or downlink.

[0100] Figure 12 is a diagram of the simplified structure of an embodiment of a TAL terminal according to an embodiment of the invention.

[0101] The TAL terminal comprises at least one microprocessor pP_TAL whose operation is controlled by the execution of a program whose instructions allow the implementation of a communication method according to the invention, a memory MEM_TAL, a transmitter EM_TAL and a receiver RE_TAL which are connected to each other by means of, for example, a bus. Of course, the constituent elements of the TAL terminal can be connected by means of a connection other than a bus.

[0102] The microprocessor pP_TAL controls the operations of the terminal TAL. The storage unit MEM_TAL stores at least the program for implementing the method according to an embodiment of the invention to be executed by the processor pP_TAL, and various data, such as parameters and / or indicators, NSSAI, 5QI, used for calculations performed by the microprocessor pP_TAL, intermediate data of calculations performed by the microprocessor pP_TAL, etc. The microprocessor pP_TAL may be formed by any known and suitable hardware or software, or by a combination of hardware and software. For example, the microprocessor pP_TAL may be formed by dedicated hardware such as a processing circuit, or by a programmable processing unit such as a central processing unit (Central Processing Unit in English) which executes a program stored in a memory thereof.

[0103] MEM_TAL memory may be formed by any suitable means capable of storing the program(s) and data in a computer-readable manner. Examples of MEM_TAL memory include non-transitory storage media such as semiconductor memory devices, and magnetic, optical, or magneto-optical recording media loaded into a read-write unit controlled by the microprocessor.

[0104] During initialization, the program code instructions are, for example, loaded into a buffer memory before being executed by the pP_TAL microprocessor. The pP_TAL microprocessor controls the various components of the TAL terminal.

[0105] Thus by executing the instructions, the microprocessor pP_TAL allows the implementation by the terminal TAL of the communication method which comprises, according to one embodiment of the invention: - reception, by the receiver RE_TAL, at a first transmission interval, TTI, of control information, DCI, comprising a first band part indicator, BWP1, to receive data associated with a first slice via the first band part, BWP1, such that:

[0106] - the control information, DCI received at the first transmission interval, TTI, further comprises a second band part indicator, BWP2, for receiving by the receiver RE_TAL or transmitting by the transmitter EM_TAL, via this second band part, BWP2, data associated with a second slot and a first switching time indicator, J 1 , for switching the active band part between the first band part, BWP1, and the second band part, BWP2.

[0107] The EM_TAL transmitter can transmit pilot signals, for example SRS, for the base station to determine the quality of the uplink channel. The RE_TAL receiver can receive pilot signals, for example DMRS, from a base station to determine the quality of the downlink channel and, by reciprocity, deduce therefrom a quality of the uplink channel. The terminal can then send back to the base station an estimate of the quality of the downlink channel. Other techniques well known to those skilled in the art are possible for channel estimation, whether uplink or downlink.

[0108] In the context of a telecommunications network with a 0-RAN type access network, illustrated by Figure 13, the communication method in its base station version can be implemented by an entity called RIC (RAN Intelligent Controller) or “near-RT RIC” (near-RealTime RIC).

[0109] In this O-RAN context the base station is disaggregated into several entities: Non-RT RIC, near-RT RIC, O-CU-CP, O-CU-UP, O-DU, O-RU. Interfaces are defined between these different entities: Al between the Non-RT RIC and near-RT RIC entities, E2 between the near-RT RIC and O-CU-CP / O-CU-UP entities, El between O-CU-CP and O-CU-UP, Fl between the O-CU-CP / O-CU-UP and O-DU entities, Open FH between the O-DU and O-RU entities.

[0110] Each entity is responsible for specific functions and a protocol layer. In particular, the O-RU entity is responsible for the low physical layer, the O-DU entity is responsible for the high physical layer and Layer 2 with the MAC protocol and scheduling. RICs are controllers that run algorithms. Algorithms with a time scale of 10 ms to 1 second run at the "near-RT RIC" level while algorithms with a time scale greater than 1 second run at the "Non-RT RIC" level.

[0111] Since the determination of control information, DCI, must be compatible with very restrictive latency times, its determination is carried out at the level of the "near-RT RIC". This entity has as input data measurements from the terminal, TAL, slice indicators, N-SSAI provided by the AMF, parameters, quality indicators, 5QI which allow it to construct a flow matrix. The matrix then makes it possible to determine the DCI and its format to be transmitted to the terminal.

Claims

CLAIMS 1. Communication method comprising: - transmission at a first transmission interval (TTI) of control information (DCI) comprising a first band part indicator (BWP1) for transmitting data associated with a first slice via the first band part (BWP1), characterized in that: - the control information (DCI) transmitted at the first transmission interval (TTI) further comprises a second band part indicator (BWP2) for transmitting or receiving, via this second band part (BWP2), data associated with a second slot and a first switching time indicator (Jl) for switching the active band part between the first band part (BWP1) and the second band part (BWP2).

2. Method according to claim 1, wherein said first switching time indicator J 1 is a time index of a first transmission slot.

3. The method of claim 1 or 2, further comprising: - before the transmission of the control information, reception of an identifier of the first tranche and an identifier of the second tranche for the association of the same terminal with these first and second tranches.

4. Method according to one of claims 1 to 3, such that the control information (DCI) transmitted at the first transmission interval (TTI) further comprises a first time offset indicator (KO) after the first transmission interval for transmitting data associated with the first free slot via the first band part (BWP1) and such that the active band part switchover occurs after the scheduling of the data associated with the first slot and transmitted via the first band part (BWP1).

5. Communication method comprising: - receiving at a first transmission interval (TTI) control information (DCI) comprising a first band part indicator (BWP1) for receiving data associated with a first slice via the first band part (BWP1), characterized in that: - the control information (DCI) received at the first transmission interval (TTI) further comprises a second band part indicator (BWP2) for receiving or transmitting, via this second band part (BWP2), data associated with a second slot and a first switching time indicator (Jl) for switching active band part between the first band part (BWP1) and the second band part (BWP2).

6. Method according to claim 5, wherein said first, respectively second, switching time indicator is a time index of a first, respectively second, transmission slot.

7. The method of claim 5 or 6, further comprising: - before receiving the control information, transmission of an identifier of the first tranche and an identifier of the second tranche for the association of the same terminal with the first and second tranches.

8. Method according to one of claims 1 to 7, such that the first strip part (BWP1) and the second strip part (BWP2) respectively benefit from different numerologies.

9. Method according to one of claims 1 to 8, such that the control information (DCI) is carried by the same control channel (PDCCH).

10. Method according to one of claims 1 to 9, such that the data associated with the first slice and the data associated with the second slice are received or transmitted in the same shared channel (PDSCH, PUSCH) of received data or the same shared channel (PUSCH, PDSCH) of transmitted data.

11. Method according to one of claims 1 to 10, such that the data associated with the first slice and the data associated with the second slice are associated with services of different types.

12. Method according to one of claims 1 to 11 such that the data associated with one of the slices is associated with a service of the type requiring high reliability and low latency, ie, URLLC.

13. Telecommunication device (T AL) comprising at least one transmitter (EM_TAL) and one receiver (RE_TAL), the device is adapted to: receive, at a first transmission interval (TTI), control information (DCI) comprising a first band part indicator (BWP1), a second band part indicator (BWP2) and a first switching time indicator (Jl) for switching the active band part between the first band part (BWP1) and the second band part (BWP2), receive or transmit data associated with a first slice via the first band part (BWP1) and, after switching the active band part, data associated with a second slice via the second band part (BWP2).

14. Telecommunication device (BS) comprising at least one transmitter (EM_BS) and one receiver (RE_BS), the device is adapted to: transmit at a first transmission interval (TTI) control information (DCI) comprising a first band part indicator (BWP1), a second band part indicator (BWP2) and a first switching time indicator (Jl) to switch the active band portion between the first band portion (BWP1) and the second band portion (BWP2), transmit data associated with a first slice via the first band portion (BWP1) and, after switching the active band portion, data associated with a second slice via the second band portion (BWP2).

15. Computer program comprising instructions for executing the steps of the method according to one of claims 1 to 12 when said program is executed by a computer.

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