METHOD FOR ENHANCED SCHEDULING OF NETWORK RESOURCES FOR REDUCED CAPABILITY USER EQUIPMENTS

Abstract

Provided is a method to operate a base station that is part of a cellular network. The base station is configured to ascertain capability information from said reduced-capability user equipment indicating a capable uplink frequency bandwidth and a capable downlink frequency bandwidth. The method includes transmitting at least one first downlink signal for user equipment considering the received capability information, said first downlink signal indicating an assignment to a scheduled uplink frequency band, and scheduling information in the scheduled downlink frequency band for synchronously transmission in a predetermined nominal spacing to said scheduled uplink frequency band based on the center of the scheduled uplink frequency band and the scheduled downlink frequency band.

Claims

1. A method to operate a base station (BS) that is part of a cellular network (CN), the base station serving a plurality of user equipments (UE), the base station (BS) operating at least in one supported frequency band in uplink direction and one in downlink direction (SUFB, SDFB), wherein the plurality of user equipments comprises at least one which is qualified as reduced-capability user equipment, wherein the base station (BS) is configured to ascertain capability information from said reduced-capability user equipment indicating a capable uplink frequency bandwidth and a capable downlink frequency bandwidth (CBW), wherein for scheduling the at least one reduced-capability user equipment (UE) the method comprises the steps for the base station (BS) of: transmitting at least one first downlink signal for said user equipment (UE) considering the received capability information, said first downlink signal indicating an assignment (UA) to a scheduled uplink frequency band (SUB), scheduling information in the scheduled downlink frequency band (SDB) for synchronously transmission in a predetermined nominal spacing (NMS) to said scheduled uplink frequency band (SUB) based on the center of the scheduled uplink frequency band (SUB) and the scheduled downlink frequency band (SDB).

2. The method according to claim 1, wherein said step of transmitting at least one first downlink signal comprises indicating a scheduled downlink frequency band (SDB), and transmitting within said scheduled downlink frequency band said assignment (UA) to the scheduled uplink frequency band (SUB).

3. The method according to claim 2, wherein the step of transmitting the first downlink signal is carried out: according to a predetermined proximity around the master information block (MIB), or as announced by the base station (BS) in a broadcast signalling, or in a fraction of the supported downlink frequency band (SDFB) identified by a hopping sequence considering a user equipment specific element, or in a fraction of the supported downlink frequency band (SDFB) identified by a hopping sequence considering a frame timing relation.

4. The method according to claim 3, further comprising the step of determining if the scheduled downlink frequency band (SDB) protrudes the supported downlink frequency band (SDFB), amending the scheduling by shifting the scheduled downlink frequency band (SDB) to the edge of the supported downlink frequency band (SDFB).

5. The method according to claim 4, wherein in case of operation of the base station (BS) in time domain duplex, the nominal spacing (NMS is zero.

6. The method according to claim 5, further comprising that after conducting an uplink transmission considering said scheduled uplink frequency band (SUB) a second scheduled downlink frequency band (SDB) is determined considering at least one out of: said predetermined proximity around the master information block (MIB), said broadcast signalling, said fraction of the supported downlink frequency band (SDB) identified by said hopping sequence, the previously used scheduled downlink frequency band (SDB).

7. A Base station (BS) that is part of a cellular network, the base station (BS) is configured to serve a plurality of user equipments, the base station (BS) operating at least in one supported frequency band in uplink direction and one in downlink direction, wherein the plurality of user equipments comprises at least one which is qualified as reduced-capability user equipment, wherein the base station (BS) is configured to ascertain capability information from said reduced-capability user equipment (UE) indicating a capable uplink frequency bandwidth and a capable downlink frequency bandwidth (CBW), wherein for scheduling the at least one reduced-capability user equipment (UE) the base station (BS) is configured to: transmit at least one first downlink signal for said user equipment (UE) considering the received capability information indicating an assignment (UA) to a scheduled uplink frequency band (SUB), schedule information in the scheduled downlink frequency band (SDB) for synchronously transmission in a predetermined nominal spacing (NMS) to said scheduled uplink frequency band (SUB) based on the center of the scheduled uplink frequency band (SUB) and the scheduled downlink frequency band (SDB).

8. The base station (BS) according to claim 7, wherein said transmitting of at least one first downlink signal comprises to indicate a scheduled downlink frequency band (SDB), and to transmit within said scheduled downlink frequency band (SDB) said assignment (UA) to the scheduled uplink frequency band (SUB).

9. The base station (BS) according to claim 8, wherein said transmitting of the first downlink signal is carried out: according to a predetermined proximity around the master information block (MIB), or as announced by the base station (BS) in a broadcast signalling, or in a fraction of the supported downlink frequency band (SDFB) identified by a hopping sequence considering a user equipment (UE) specific element, or in a fraction of the supported downlink frequency band (SDFB) identified by a hopping sequence considering a frame timing relation.

10. The base station (BS) according to claim 9, further configured to determine if the scheduled downlink frequency band (SDB) protrudes the supported downlink frequency band (SDFB), to amend the scheduling by shifting the scheduled downlink frequency (SDB) band to the edge of the supported downlink frequency band (SDFB).

11. The base station (BS) according to claim 10, further configured that after conducting an uplink transmission considering said scheduled uplink frequency band (SUB) to determine a second scheduled downlink frequency band (SDB) considering at least one out of: said predetermined proximity around the master information block (MIB), said broadcast signalling, said fraction of the supported downlink frequency band (SDFB) identified by said hopping sequence, the previously used scheduled downlink frequency band (SDB).

12. A method for a user equipment (UE) capable of operating with one of a plurality of base station (BS) of a cellular network (CN), hereinafter the serving base station, said user equipment (UE) is qualified as reduced-capability user equipment, said user equipment (UE) maintaining a capable uplink frequency bandwidth and a capable downlink frequency bandwidth (CBW), the method comprising the steps of: submitting capability information to the serving base station (BS), receiving at least one first downlink signal from the serving base station (BS), deriving from the first downlink signal the assignment (UA) to a scheduled uplink frequency band (SUB), determining the scheduled downlink frequency band (SDB) by considering a predetermined nominal spacing (NMS) to the center of the scheduled uplink frequency band (SUB) and the scheduled downlink frequency band (SDB), synchronously monitoring the scheduled downlink frequency band (SDB) for signals from the base station (BS) and transmitting at least one signal to the base station (BS) using the scheduled uplink frequency band (SUB).

13. The method according to claim 12, wherein the step of receiving said at least one first downlink signal, is carried out: according to a predetermined proximity around the master information block (MIB), or as announced by the base station (BS) in a broadcast signalling, or in a fraction of the supported downlink frequency band (SDB) identified by a hopping sequence considering a user equipment (UE) specific element.

14. The method according to claim 13, further comprising the step of determining if the scheduled downlink frequency band (SDB) protrudes the supported downlink frequency band (SDFB), shifting the scheduled downlink frequency band (SDB) to the edge of the supported downlink frequency band (SDFB).

15. The method according to claim 14, further comprising after conducting an uplink transmission considering said scheduled uplink frequency band (SUB) the step of determining a second scheduled downlink frequency band (SDB) considering at least one out of: said predetermined proximity around the master information block (MIB), said broadcast signalling, said fraction of the supported downlink frequency band (SDFB) identified by said hopping sequence, the previously used scheduled downlink frequency band (SDB).

16. User equipment (UE) capable of operating with one of a plurality of base station (BS) of a cellular network (CN), hereinafter the serving base station (BS), said user equipment (UE) is qualified as reduced-capability user equipment, said user equipment (UE) maintaining a capable uplink frequency bandwidth and a capable downlink frequency bandwidth (CBW), the user equipment (UE) configured to: submit a capability information to the serving base station (BS), receive at least one first downlink signal from the serving base station (BS), derive from the first downlink signal the assignment (UA) to a scheduled uplink frequency band (SUB), determine the scheduled downlink frequency band (SDB) by considering a predetermined nominal spacing (NMS) to the center of the scheduled uplink frequency band (SUB) and the scheduled downlink frequency band (SDB), synchronously monitor the scheduled downlink frequency band (SDB) for signals from the base station (BS) and transmit at least one signal to the base station (BS) using the scheduled uplink frequency band (SUB).

17. User equipment (UE) according to claim 16, wherein said receiving of the at least one first downlink signal, is carried out: according to a predetermined proximity around the master information block (MIB), or as announced by the base station (BS) in a broadcast signalling, or in a fraction of the supported downlink frequency band (SDFB) identified by a hopping sequence considering a user equipment (UE) specific element.

18. User equipment (UE) according to at least one of the claim 16 or 17, further configured to determine if the scheduled downlink frequency band (SDB) protrudes the supported downlink frequency band (SDFB), if so shift the scheduled downlink frequency band (SDB) to the edge of the supported downlink frequency band (SDFB).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0133] The following description and the annexed drawings set forth in detail certain illustrative aspects and are indicative of but a few of the various ways in which the principles of the embodiments may be employed. Characteristics and advantages of the present invention will appear when reading the following description and annexed drawings of advantageous embodiments given as illustrative but not restrictive examples.

[0134] FIG. 1 represents a first exemplifying scheduling of uplink and downlink communication between a base station and a user equipment of the type to which the present invention is applied as an embodiment;

[0135] FIG. 2 represents a second exemplifying scheduling of uplink and downlink communication of the type to which the present invention is applied as an embodiment;

[0136] FIG. 3 shows a sequence diagram according to an exemplifying embodiment of the invention.

[0137] FIG. 1 schematically shows a user equipment UE operating with a base station BS being part of a cellular network CN. The base station BS is in particular configured to comply with the cellular wireless communication standards of 2G, 3G, 4G, 5G and/or beyond.

[0138] The user equipment UE is camping on the base station. It is a reduced-capability user equipment, which means it is not capable to process the full supported downlink frequency band SDFB and/or the supported uplink frequency band SUFB of the base station BS. In the context of 5G resp. NR such reduced-capability devices are called NR light or NR-REDCAP. This implies that the reduced-capability user equipment is expected to operate in full duplex, regardless of the reduced-capability qualification. This makes this deployment different to e.g. NB-IoT, where no duplex signalling is possible. The base station BS is aware of the capable frequency bandwidth CBW of the user equipment UE, which preferably was exchanged during the initial process of camping on the base station as part of the capability information.

[0139] The horizontal axis depicts the frequency where the deployment of the base stations BS supported frequency bands SDFB and SUFB are shown. Here it is shown a frequency division duplex (FDD) deployment, that means the supported uplink and the downlink frequency bands are separated.

[0140] This separation is not arbitrary, but in a predetermined fixed distance depicting the nominal spacing NMS. This fixed nominal spacing NMS is preferably derived from the respective implemented technology standard, like for LTE 3GPP TS 36.101.

[0141] For serving a reduced-capability user equipment UE the base station BS is carrying out the following steps, shown in vertical order, indicating the time. That means, what is in the same height, it is supposed to happen more or less in parallel.

[0142] First in step S1 the base station BS considers in a certain range, which can be decoded by the camping at least one reduced-capability user equipment—therefore complying with the capable frequency bandwidth CBW of the user equipment—that said at least one user equipment will monitor signals dedicated for said user equipment.

[0143] Preferably this—at least for LTE deployment—is deployed in close proximity to the master information block MIB, which needs to be read by any camping user equipment anyway, at least for receiving always up to date system information and any other broadcasted information.

[0144] Within this scheduled range the base station BS sends for an imminent data transmission session a first downlink signal for said user equipment UE indicating an uplink assignment UA for a scheduled uplink frequency band SUB. This is an indication where in the supported uplink frequency band SUFB of the base station BS the user equipment UE may carry out data transmission. Such data transmission are expected to happen in parallel to a downlink data transmission from the base station BS, which the user equipment UE is expected to monitor.

[0145] For that it requires to make available the scheduled downlink frequency band SDB for the next time period, as this does not stay constant.

[0146] This is achieved from the base station BS by a deployment of the scheduled downlink frequency band SDB in a constant distance according to the nominal spacing NMS to the scheduled uplink frequency band SUB.

[0147] So in step S2 both scheduled frequency bands in the uplink and the downlink direction are deployed and supposed to be monitored by the user equipment in the downlink and used for data transmission in the uplink.

[0148] At least one indication is transmitted by the base station as indicated in step S3. Here another uplink assignment UA is signalled to the user equipment UE within the scheduled downlink frequency band SDB.

[0149] This is following a new scheduling for the next time period, where the deployment for this user equipment UE may change.

[0150] As it is shown for the uplink transmission the uplink assignment UA for step S4 shows a scheduled uplink frequency band SUB in a completely different area of the supported uplink frequency band SUFB.

[0151] Consequently also the scheduled downlink frequency band SDB is moved taking into account the nominal spacing NMS.

[0152] With that embodiment it is shown in an exemplifying manner the regular scheduling conducted by the base station BS, made available for the user equipment to be always assured that a limited range complying with the capable frequency bandwidth CBW of the user equipment is used for scheduling purposes.

[0153] In FIG. 2 it is shown a second example of the invention applied in a similar way as before.

[0154] Steps S11-S14 more or less correspond to the steps S1-S4 of FIG. 1.

[0155] In S13 it is however indicated with the uplink assignment UA a scheduled uplink frequency band SUB comparably close to the edge of the supported uplink frequency band of the base station. Due to the total size of the frequency bandwidth it fully fits into the supported uplink frequency band.

[0156] However the corresponding parallel scheduled downlink frequency band SDB is larger in size than the scheduled uplink frequency band SUB. This leads due to the fixed distance of the nominal spacing NMS, that as shown in step S14 parts of the scheduled downlink frequency band SDB protrude the edge of the supported downlink frequency band SDFB.

[0157] In that situation in step S15 the scheduled downlink frequency band SDB is shifted to the edge of the supported downlink frequency band SDFB. This assures that the whole scheduled downlink frequency band may be used in that step, in order to assure the possible data throughput, if needed.

[0158] This effect becomes in particular apparent with the next deployed scheduled uplink frequency band SUB in step S16. According to the uplink assignment UA this is deployed right at the edge of the supported uplink frequency band SUFB. And moreover it is remarkably small, which might be due to a low amount of requested resources for uplink transmissions by the user equipment UE.

[0159] This leads to the effect that by applying the nominal spacing NMS practically half of the resulting scheduled downlink frequency band SDB is lying outside of the supported downlink frequency band SDFB.

[0160] In step S17 this is mitigated by shifting again the resulting scheduled downlink frequency band SDB to the edge of the supported downlink frequency band SDFB.

[0161] This exemplifying embodiment shows, that it is reliably assured that the scheduling in up- and downlink direction is fully usable for the user equipment UE.

[0162] FIG. 3 shows a sequence diagram indicating the signalled messages between user equipment UE and base station BS in an exemplifying embodiment of the invention.

[0163] The sequence starts with message M1, in particular in course with the procedures carried out for camping on the base station, wherein the user equipment sends capability information to the base station.

[0164] In particular during registration procedure of the user equipment UE, the base station issues a UE capability request to the user equipment. Said capability request is issued by the cellular network if user equipment capabilities have not been forwarded by the previous serving base stations. In case of an initial attach the user equipment sends its capabilities as part of the network registration procedure to the base station.

[0165] In LTE in general user equipment's capabilities are maintained in the MME, i.e. being part of the NAS procedure TS23.401 and carried out via RRC procedures TS36.331 e.g. If the user equipment has changed its E-UTRAN radio access capabilities, it shall request higher layers to initiate the necessary NAS procedures (see TS 23.401) that would result in the update of user equipment's radio access capabilities using a new RRC connection. Likewise method for NR exists involving TS 38.331, TS.23.401 and the communication is done by means of the AMF (Access and Mobility Management Function). In response or alternatively as initial registration the user equipment submits with the UE capability message M1 its capabilities to the base station. The UE capability message M1 comprises all information relating to UE capabilities. This relates in particular to all capable frequency bands of the user equipment, both in the uplink and the downlink.

[0166] Directly after this message M1, or after some waiting time, in particular when a data transmission session becomes due, the base station BS sends with message M2 a first downlink signal to the user equipment. The user equipment knows which frequency range to monitor for such downlink signal message from the base station based on previously acknowledged or defined information, e.g. in proximity to the master information block MIB.

[0167] Part of the downlink signal M2 is an uplink assignment UA. Based on the uplink assignment UA the user equipment knows where in the supported uplink frequency range of base station BS it may carry out uplink transmission.

[0168] In this embodiment no uplink transmission are due, therefore no signals/messages are sent from the user equipment to the base station. However the base station needs to carry out parallel downlink transmissions to the user equipment. These need to be scheduled and the user equipment UE needs to know where these downlink transmissions are scheduled.

[0169] This is achieved indirectly through the uplink assignment UA which was submitted with message M2. With applying a constant nominal spacing on the center of the uplink assignment UA the user equipment UE can easily derive the center of the scheduled downlink frequency band SDB. For that the user equipment UE applies the entire capable frequency bandwidth CBW. However due to other distribution rules only a part of the scheduled downlink frequency bandwidth SDB may be used for scheduling indication by the base station BS, and hence the user equipment UE only listens to that fraction of its capable frequency band CBW. Such measures are e.g. in LTE known where all camping user equipments UE are distributed over the capable supported frequency range, so that each user equipment listens equally often to each frequency range, and each frequency range is equally often used for scheduling for all user equipments UE.

[0170] If the scheduled downlink frequency band SDB is fully positioned within the supported downlink frequency band SDFB of the base station BS, then the user equipment UE is prepared to monitor the data transmissions of the base station BS within the scheduled downlink frequency band SDB with message M3, until data dedicated for the user equipment are submitted.

[0171] With message step M4 the user equipment UE carries out said monitoring and decodes signals or data packets dedicated for the user equipment UE.

[0172] In the above detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that the various embodiments of the invention, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein in connection with one embodiment may be implemented within other embodiments without departing from the scope of the invention. In addition, it is to be understood that the location or arrangement of individual elements within each disclosed embodiment may be modified without departing from the scope of the invention. The above detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, appropriately interpreted, along with the full range of equivalents to which the claims are entitled.