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EP-4736561-A1 - A METHOD AND APPARATUSES FOR PROVIDING GRANT-BASED SCHEDULING

EP4736561A1EP 4736561 A1EP4736561 A1EP 4736561A1EP-4736561-A1

Abstract

Embodiments described herein relate to a method and apparatuses for grant-based scheduling of frequency resource units to one or more user equipments. A method comprises receiving (201) a first scheduling request, SR, from a first User Equipment, UE; responsive to receiving the first SR, selecting (202) to allocate frequency resource units, FRUs, of a first uplink time-based transmission unit, UTTU, to the first UE; determining (203) a first number of FRUs to allocate to the first UE based on whether there would be un-allocated FRUs in the first UTTU after an initial allocation of FRUs in the first UTTU to the one or more UEs comprising the first UE; and transmitting (204), to the first UE, an uplink grant for transmission using the first number of FRUs.

Inventors

  • TUMULA, Chaitanya

Assignees

  • Telefonaktiebolaget LM Ericsson (publ)

Dates

Publication Date
20260506
Application Date
20230630

Claims (20)

  1. CLAIMS 1. A method performed by a network node for grant-based scheduling of frequency resource units, FRUs to one or more user equipments, the method comprising: receiving (201) a first scheduling request, SR, from a first User Equipment, UE; responsive to receiving the first SR, selecting (202) to allocate FRUs of a first uplink time-based transmission unit, UTTU, to the first UE; determining (203) a first number of FRUs to allocate to the first UE based on whether there would be un-allocated FRUs in the first UTTU after an initial allocation of FRUs in the first UTTU to the one or more UEs comprising the first UE; and transmitting (204), to the first UE, an uplink grant for transmission using the first number of FRUs.
  2. 2. The method of claim 1 wherein the first SR is associated with a first logical channel.
  3. 3. The method of claim 1 or 2, further comprising determining whether there would be un-allocated FRUs in the first UTTU by: performing the initial allocation by allocating (403) an allocated number of FRUs comprising respective initial numbers of FRUs allocated to the one or more UEs; and determining (404) whether there are un-allocated FRUs in the first UTTU after the initial allocation based on a total number of FRUs in the first UTTU and an allocated number of FRUs in the first UTTU that have been allocated to the one or more UEs.
  4. 4. The method of claim 3, wherein the respective initial number of FRUs for the first UEs is a respective number of FRUs required for the first UE to send a buffer status report.
  5. 5. The method of claim 3 or 4, wherein determining (404) whether there are un- allocated FRUs comprises: responsive to the total number of FRUs being equal to the allocated number of FRUs, determining that there are no un-allocated FRUs in the first UTTU, and responsive to the total number of FRUs being greater than the allocated number of FRUs determining that there are un-allocated FRUs in the first UTTU.
  6. 6. The method of claim 5, wherein determining the first number of FRUs further comprises: responsive to determining that there are no un-allocated FRUs in the first UTTU, selecting (415) the respective initial number of FRUs for the first UE as the first number of FRUs.
  7. 7. The method of claim 5 or 6, wherein determining the first number of FRUs further comprises: responsive to determining that there are un-allocated FRUs in the first UTTU, selecting (405) a number of the un-allocated FRUs to be allocated to the first UE in addition to the respective initial number of FRUs for the first UE.
  8. 8. The method of claim 7, wherein selecting the number of the un-allocated FRUs to be allocated to the first UE comprises: identifying (301) one or more qualifying SRs comprising the first SR; and distributing (302) the un-allocated FRUs amongst one or more UEs that sent the one or more qualifying SRs.
  9. 9. The method of claim 8, wherein identifying the one or more qualifying SRs comprises selecting the one or more qualifying SRs from a set of one or more SRs each received from a UE that has each been allocated at least one FRU in the first UTTU, wherein each qualifying SR is selected based on one or more of: a logical channel priority associated with the qualifying SR; a priority index associated with the qualifying SR; a prediction of a logical channel buffer size for a UE that sent the qualifying SR; a relationship between the predicted logical channel buffer size for the UE that sent the qualifying SR and the un-allocated FRUs in the first UTTU; and a measured uplink signal to interference plus noise power ratio, SINR, for the UE that sent the qualifying SR.
  10. 10. The method of claim 8 or 9, wherein the un-allocated FRUs are distributed amongst the one or more UEs that sent the one or more qualifying SRs based on one or more characteristics of at least one qualifying SR.
  11. 11. The method of claim 10, wherein the one or more characteristics comprise one or more of: a logical channel priority associated with the qualifying SR; a priority index associated with the qualifying SR; a prediction of a logical channel buffer size for a UE that sent the qualifying SR; a relationship between the predicted logical channel buffer size for the UE that sent the qualifying SR and the number of un-allocated FRUs in the first UTTU; and a measured uplink signal to interference plus noise power ratio, SINR, for the UE that sent the qualifying SR.
  12. 12. The method of any preceding claim, wherein determining the first number of FRUs to allocate to the first UE is performed responsive to identifying that the first SR is a qualifying SR.
  13. 13. The method of any preceding claim, wherein determining the first number of FRUs to allocate to the first UE is performed responsive to determining that a load associated with the network node satisfies a criterion.
  14. 14. The method of claim 13, wherein the criterion is satisfied when the load associated with the network node is below a threshold value.
  15. 15. The method of any preceding claim, wherein the method further comprises: after transmitting the uplink grant, receiving (406, 418), from the first UE, data on at least one of the first number of FRUs allocated to the first UE.
  16. 16. The method of any preceding claim, wherein the FRUs are resource blocks.
  17. 17. A network node (510A, 510B, 600, 700) for grant-based scheduling of frequency resource units, FRUs to one or more user equipments, the network node (510A, 510B, 600, 700) adapted to: receive (201) a first scheduling request, SR, from a first User Equipment, UE; responsive to receiving the first SR, select (202) to allocate FRUs of a first uplink time-based transmission unit, UTTU, to the first UE; determine (203) a first number of FRUs to allocate to the first UE based on whether there would be un-allocated FRUs in the first UTTU after an initial allocation of FRUs in the first UTTU to the one or more UEs comprising the first UE; and transmit (204), to the first UE, an uplink grant for transmission using the first number of FRUs.
  18. 18. The network node (510A, 510B, 600, 700) of claim 17, further adapted to perform the method of any of claims 2-16.
  19. 19. A network node for grant-based scheduling of frequency resource units, FRUs to one or more user equipments, the network node comprising a processor and a memory, the memory containing instructions executable by the processor whereby the network node is operative to: receive (201) a first scheduling request, SR, from a first User Equipment, UE; responsive to receiving the first SR, select (202) to allocate FRUs of a first uplink time-based transmission unit, UTTU, to the first UE; determine (203) a first number of FRUs to allocate to the first UE based on whether there would be un-allocated FRUs in the first UTTU after an initial allocation of FRUs in the first UTTU to the one or more UEs comprising the first UE; and transmit (204), to the first UE, an uplink grant for transmission using the first number of FRUs.
  20. 20. The network node of claim 19, further operative to perform the method of any of claims 2-16.

Description

A METHOD AND APPARATUSES FOR PROVIDING GRANT-BASED SCHEDULING Technical Field Embodiments described herein relate to grant-based scheduling of frequency resource units to one or more user equipments. Background In wireless communication systems such as fifth generation (5G) New Radio (NR), there are two types of uplink transmissions from a user equipment (UE): grant-based transmissions and grant-less transmissions. In grant-based transmissions, a UE that has data to transmit uses a Scheduling Request (SR) procedure to request resources for a new uplink data transmission. In grant-less transmissions, resources for uplink (UL) Physical Uplink Shared Channel (PUSCH) transmissions are pre-allocated (reserved) and a UE that has data to transmit uses the first available reserved resources to transmit the data. Grant-less transmissions can be used to reduce the latency in the system, since UEs do not have to wait for the network to allocate resources for the transmission, but they are inefficient from a resource usage perspective compared to grant-based transmission. Figure 1 is a flow chart illustrating a grant-based transmission procedure for the transmission of data from a UE in the uplink. At step 101, data belonging to a specific logical channel (LC) arrives for transmission within the UE buffer. Thus, the UE has data to send in the uplink. At step 102, the Medium Access Control (MAC) layer in the UE triggers the physical (PHY) layer to send an SR using Physical Uplink Control Channel (PUCCH) resources that have been configured by the gNodeB (gNB) for the UE. The UE sends an SR using PUCCH resources in this manner whenever new data arrives at the UE buffer and there is no uplink grant already allocated for the UE. The gNB configures the PUCCH resources for SR transmission for each UE, and this resource configuration comprises various parameters related to, for example, the period between SR resources, an offset relative to a reference slot number, and a maximum number of times an SR can be sent. Radio Resource Control (RRC) connection setup or RRC reconfiguration request messages are used to configure the scheduling request related parameters. The PUCCH resources configured for SR transmission may be associated with a specific LC or a group of LCs. Any PUCCH format can be used to send an SR, i.e., any of formats 0, 1, 2, 3 and 4, although typically SR PUCCH resources are configured using either PUCCH format 0 or PUCCH format 1. Other PUCCH formats can be used when PUCCH transmissions coincide. For example, an SR transmission using PUCCH format 0 may coincide with a CSI Reporting transmission using PUCCH format 3. In that case, both the SR and the CSI Report can be transmitted on the same PUCCH format 3 resource. The MAC layer is controlling the SR and the information element (IE) MAC- CellGroupConfig is used to configure MAC parameters for a cell group. MAC-CellGroupConfig ::= SEQUENCE { drx-Config } OPTIONAL, -- Need M schedulingRequestConfig bsr-Config tag-Config phr-Config skipUplinkTxDynamic BOOLEAN, ... } IE SchedulingRequestConfig is used to configure the parameters, for the dedicated scheduling request (SR) resources. RRC Parameters SchedulingRequestConfig ::= SEQUENCE { schedulingRequestToAddModList SEQUENCE (SIZE (1..maxNrofSR- ConfigPerCellGroup)) OF SchedulingRequestToAddMod OPTIONAL, schedulingRequestToReleaseList SEQUENCE (SIZE (1..maxNrofSR- ConfigPerCellGroup)) OF SchedulingRequestId OPTIONAL -- Need N } SchedulingRequestToAddMod ::= SEQUENCE { schedulingRequestId SchedulingRequestId, sr-ProhibitTimer ENUMERATED {ms1, ms2, ms4, ms8, ms16, ms32, ms64, ms128} sr-TransMax ENUMERATED {n4, n8, n16, n32, n64, spare3, spare2, spare1} } schedulingRequestId : Used to modify a SR configuration and to indicate, in LogicalChannelConfig, the SR configuration to which a logical channel is mapped, and to indicate, in SchedulingRequestresourceConfig, the SR configuration for which a scheduling request resource is used. - The IE "SchedulingRequestId" is used to identify a Scheduling Request instance in the MAC layer. SchedulingRequestId ::= INTEGER (0..7) The a pointer towards an additional set of parameters associated with the Scheduling Request resources. Each SR configuration corresponds to one or more logical channels. Each logical channel may be mapped to zero or one SR configuration, which is configured by RRC. The RRC layer configures the following parameters for the scheduling request procedure: sr-ProhibitTimer defines the minimum time between consecutive SRs, i.e. the UE has to wait ProhitnitTimer amount of time before sending another SR. This is to avoid overloading UL resources with very fast SR requests from UEs. sr-TransMax specifies the maximum number of SRs a UE can send to a gNB. If the UE has sent maximum number of SRs and has not received UL resources for data transmission, the UE releases its PUCCH resources and SRS resources and initiates the RACH procedure. SchedulingRequestRe