WO2023213397A1

WO2023213397A1 - Scheduled throughput in uplink in a distributed base station

Info

Publication number: WO2023213397A1
Application number: PCT/EP2022/062079
Authority: WO
Inventors: Martin Kollar; Krzysztof TATARCZYK
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2023-11-09
Anticipated expiration: 2024-11-05
Also published as: EP4520074A1

Abstract

A control unit of a base station of a radio access network receives (S21 1 ), from at least one distribution unit, information on a time period. The control unit receives (S213) protocol data units associated with bursts of data received by the at least one distribution unit from at least one user equipment. The control unit calculates (S215) durations of the bursts based on the protocol data units and based on the time period, and calculates (S217), for the at least one user equipment, a scheduled throughput in uplink direction based on the durations of the bursts.

Description

SCHEDULED THROUGHPUT IN UPLINK IN A DISTRIBUTED BASE STATION

TECHNI CAL FI ELD

At least som e exam ple em bodiments relate to com m unication networks, e.g. cellular radio networks com plying with 2G, 3G, 4G, 5G, 6G access networks, ORAN, etc.

BACKGROUND

An end user throughput is one of the Key Perform ance I ndicators ( KPI s) used to m onitor quality of services perceived by the end user. Services provided by E- UTRAN are based on I P blocks, which are grouped into bursts/delivery. From the point of view what the end user perceives it is crucial to measure quality of the services as Scheduled I P Throughput.

LI ST OF ABBREVIATI ONS

2G Second Generation

3GPP Third Generation Partnership Project

4G Fourth Generation

5G Fifth Generation

6G Sixth Generation

BSR Buffer Status Report

CA Channel Aggregation

CP Control Plane

CU Control Unit

DC Dual Connectivity

DRB Data Radio Bearer

DU Distribution Unit eNB evolved NodeB

E- UTRAN Evolved UTRAN

I P I nternet Protocol

KPI Key Perform ance I ndicator

LTE Long Term 3GPP Evolution

MAC Medium Access Control MDT Minim ization of Drive Tests

NR New Radio

ORAN Open RAN

PDCP Packet Data Configuration Protocol

PDU Protocol Data Unit

QI QoS Identifier

QoS Quality of Provided Services

RLC Radio Link Control

SDU Service Data Unit

UE User Equipment

UL Uplink

UMTS Universal Mobile Telecom m unications System

UP User Plane

UTRAN UMTS Terrestrial Radio Access Network

LI ST OF REFERENCES

3GPP TS 32.425 Version 17.0.1 , chapter 4.4.6.2

3GPP TS 36.314 Version 17.0.0, chapter 4.1 .6.2

3GPP TS 32.450 Version 17.0.0, chapter 6.3.1 .1

3GPP TS 28.552 Version 17.6.0, chapter 5.1 .1 .3.3

3GPP TS 38.425 Version 17.0.0, chapter 5.5.2.3

3GPP TS 38.314 Version 17.0.0, chapter 4.2.1 .2

SUMMARY

According to at least some example em bodim ents, throughput measurement that is independent of bursty traffic pattern is provided for a distributed system which com prises control units and distribution units.

According to at least some example em bodim ents, CU UP is m ade aware of UL data division into bursts on MAC level in DU for measuring Scheduled I P throughput in UL. According to at least some example embodiments, methods, apparatuses and non-transitory computer-readable storage media are provided as specified by the appended claims.

According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

I n the following at least some example embodiments will be described with reference to the accompanying drawings.

BRI EF DESCRI PTI ON OF THE DRAWI NGS

Fig. 1 shows a diagram illustrating data division into samples based on buffer filling.

Fig. 2 shows flowcharts illustrating processes for calculating a scheduled throughput in uplink direction according to at least some example embodiments.

Fig. 3 shows a diagram illustrating calculation of burst duration for one distribution unit according to at least some example embodiments.

Fig. 4 shows a diagram illustrating calculation of burst duration for two distribution units according to at least some example embodiments.

Fig. 5 shows a diagram illustrating measurement for Scheduled I P Throughput in UL per QoS group according to at least some example embodiments.

Fig. 6 shows a schematic block diagram illustrating a configuration of a control unit and a distribution unit in which at least some example embodiments are implementable. Fig. 7 shows a diagram illustrating a curve "BSR true".

Fig. 8 shows a diagram illustrating a curve "BSR estimated" derived according to at least some example embodiments.

Fig. 9 shows a diagram illustrating the difference between the curves "BSR true" and "BSR estimated".

DESCRI PTI ON OF THE EMBODI MENTS

As mentioned above, measuring the Scheduled I P Throughput is an issue when monitoring quality of services perceived by the end user.

I n E-UTRAN, 3GPP TS 32.425, chapter 4.4.6.2, 3GPP TS 36.314, chapter

4.1 .6.2, and 3GP TS 32.450, chapter 6.3.1 .1 define a way how to measure so called "Scheduled I P Throughput" per QCI in UL direction. The principle of the measurement can be summarized by the following formula:

where ThpVolUL represents a volume received from a UE for a particular sample on PDCP SDU level, and ThpTimellL represents a burst duration on MAC level.

Fig. 1 shows a diagram illustrating data division into samples based on buffer filling. I n Fig. 1 , two samples, Sample 1 and Sample 2, are identified during a session of the UE.

As per Equation ( 1 ) , volume and time of all involved samples from an observed time interval are summed up and average throughput is calculated. To achieve a throughput measurement that is independent of bursty traffic pattern, idle gaps between incom ing data is not to be included in the measurements. That shall be done as considering each burst of data as one sample. According to Fig.1 , gaps between the bursts are identified based on empty buffer which is in UL direction identified on MAC level based on Buffer status reporting (BSR) from UE to eNB.

Regarding a 5G com munication system , currently in 3GPP TS 28.552, chapter 5.1 .1 .3.3, "Average UL UE throughput in gNB" is defined with throughput volume counted on RLC SDU level and possibility to measure the throughput within a Distribution Unit (DU) only, which introduces the following lim itations:

1 . The measured throughput is not provided on I P (PDCP SDU) level.

2. I n case UL CA and/or NR Dual Connectivity (DC) with transmission in UL over more than one DU for the UE is enabled the measured throughput is not representing end user perception as only its fractions per the involved DUs are measured.

The above limitations can be fixed with movement of the measurement from DU to CU UP. However, in 5G, a distributed type of network is adopted in which CU and DU are acting as different nodes connected via F1 interface and, in addition, even within CU, CP and UP may be distributed and interconnected via E1 interface. Thus, the PDCP layer located in CU-UP has no information about RLC and MAC layers that are in DU. Nor CU-UP is aware of BSR from UE side in the DU and, thus, has no knowledge about the division of the received data in UL into bursts.

I n other words, the CU-UP is not able to identify the UL bursts in similar way as E-UTRAN does for measurement of Scheduled I P throughput in UL as mentioned above. To make CU-UP aware of the situation in DU would mean to transm it all relevant information of each BSR and time stamp when it was received from UE which is not feasible as it would overload completely the F1 -U interface with such information. At least some example embodiments intend to solve the problem via proposing a new method for making CU UP aware of UL data division into bursts on MAC level in DU and measuring Scheduled I P throughput in UL.

According to at least some example embodiments, process 1 illustrated in Fig. 2 is for use by a control unit of a base station of a radio access network. According to at least some example embodiments, the radio access network complies with 5G, the control unit resides on user plane, and/or the control unit comprises a packet data configuration protocol (PDCP) layer. For example, process 1 is started when measurement of Scheduled I P Throughput in UL is started for a given observation interval.

I n step S21 1 , information on a time period (e.g. Average time difference between two consequent UL RLC SDUs) is received from at least one distribution unit. Then, process 1 advances to step S213. For example, the information is received via an F1 -U interface.

According to at least some example embodiments, the information on the time period is received with a configurable time interval. For example, the information on the time period is received with a time interval of hundreds of m illiseconds.

According to at least some example embodiments, the information on the time period is received if a value of the time period has changed more than a predeterm ined threshold.

According to at least some example embodiments, the time period is an average time difference between two consecutive service data units associated with the bursts at the at least one distribution unit. For example, the service data units are uplink RLC service data units.

I n step S213, protocol data units associated with bursts of data are received. The bursts of data are received by the at least one distribution unit from at least one UE. Then, process 1 advances to step S215. For example, the protocol data units are PDCP protocol data units.

According to at least some example embodiments, the time period is related to at least one of service quality and radio bearer of the at least one user equipment which transmits the bursts of data.

I n step S215, durations of the bursts are calculated based on the protocol data units and based on the time period. Then, process 1 advances to step S217.

According to at least some example embodiments, in step S215, a duration of a burst of the bursts is measured from a first point in time until a second point in time, by: obtaining the first point in time as a time T1 at which a first protocol data unit PDU1 of the burst has been received at the control unit, starting, at the time T1 , a timer TN1 which is equal to the time period lastly received from the at least one distribution unit associated with the first protocol data unit PDU1 , in case a next protocol data unit PDU2 has been received at a time T2 while the timer TN1 is running, continuing counting the duration of the burst and starting, at the time T2, a timer TN2 which is equal to the time period lastly received from the at least one distribution unit associated with the next protocol data unit PDU2, and repeating the continuing of the counting and starting of timer until a protocol data unit PDUN+ 1 has been received after a timer TNN expired, and obtaining the second point in time as a time TN at which a protocol data unit PDUN has been received at the control unit, wherein the protocol data unit PDUN+ 1 represents start of a new burst of the bursts, and duration of the new burst is measured from first point in time until second point in time.

According to at least some example embodiments, process 1 further comprises a step (not shown) of receiving, from the at least one distribution unit, information on an uplink delivery time (e.g. UL DU delivery time).

According to at least some example embodiments, in step S215, the first point in time is obtained by subtracting, from the time T1 , the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDU1 , and the second point in time is obtained by subtracting, from the time TN, the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDUN.

According to at least some example embodiments, the uplink delivery time is related to at least one of service quality and radio bearer of the at least one user equipment.

According to at least some example embodiments, the uplink delivery time represents an averaged uplink delay measured at the distribution unit for a radio bearer associated with the bursts.

According to at least some example embodiments, the information on the uplink delivery time is received with a configurable time interval. For example, the information on the uplink delivery time is received with a time interval of hundreds of m illiseconds.

According to at least some example embodiments, the information on the uplink delivery time is received if a value of the uplink delivery time has changed more than a predeterm ined threshold. I n step S217, for at least one user equipment, a scheduled throughput in uplink direction is calculated based on the durations of the bursts. Then, process 1 ends.

According to at least some example embodiments, the scheduled throughput in uplink direction is calculated for the at least one user equipment based on the durations of the bursts and based on a volume of service data units received for the bursts at the control unit.

According to at least some example embodiments, in step S217, at the end of the observation interval: a total volume is obtained as a sum of volumes of the bursts of the at least one user equipment related to a given quality of service identifier, a total time is obtained as a sum of the burst durations of the at least one user equipment related to the given quality of service identifier, and the scheduled throughput in the uplink direction for the given quality of service identifier is obtained as an averaged scheduled throughput in the uplink direction per user equipment and given quality of service identifier by dividing the total volume by the total time.

According to at least some example embodiments, the volumes of the bursts are volumes of PDCP service data units received for the bursts.

According to at least some example embodiments, the scheduled throughput is a scheduled I P throughput.

Fig. 2 also illustrated a process 2 for calculating a scheduled throughput in uplink direction according to at least some example embodiments.

According to at least some example embodiments, process 2 is for use by a distribution unit of a base station of a radio access network. According to at least some example embodiments, the radio access network complies with 5G, and the distribution unit comprises a MAC layer and an RLC layer. According to at least some example embodiments, process 2 is started when the distribution unit receives bursts of data from at least one user equipment.

I n step S221 , an average time difference between two consecutive service data units associated with the bursts of data is calculated as a time period (e.g. average time difference between two consequent UL RLC SDUs) . Then, process 2 advances to step S223.

According to at least some example embodiments, the information on the time period is transm itted with a configurable time interval. For example, the information on the time period is transm itted with a time interval of hundreds of m illiseconds.

According to at least some example embodiments, the information on the time period is transmitted if a value of the time period has changed more than a predeterm ined threshold.

I n step S223, information on the time period is reported to a control unit which receives packet data units associated with the bursts. Then, process 2 ends.

According to at least some example embodiments, process 2 further comprises a step (not shown) of transmitting, to the control unit, information on an uplink delivery time (e.g. UL DU delivery time).

According to at least some example embodiments, the uplink delivery time is related to at least one of service quality and radio bearer of the at least one user equipment. According to at least some example embodiments, as the uplink delivery time, an averaged uplink delay for a radio bearer associated with the bursts is measured.

According to at least some example embodiments, the information on the uplink delivery time is transmitted with a configurable time interval. For example, the information on the uplink delivery time is transm itted with a time interval of hundreds of m illiseconds.

According to at least some example embodiments, the information on the uplink delivery time is transmitted if a value of the uplink delivery time has changed more than a predeterm ined threshold.

According to at least some example embodiments, the information on at least one of the time period and the uplink delivery time is comm unicated via an F1 -U interface.

According to at least some example embodiments, the protocol data units are PDCP protocol data units.

According to at least some example embodiments, the service data units associated with the bursts at the at least one distribution unit are uplink RLC service data units.

According to at least some example embodiments, the service data units received for the bursts at the control unit are PDCP service data units.

According to at least some example embodiments, duration of a UL burst related to a given 5QI/DRB of a UE for the intention of Scheduled I P throughput in UL is measured from a point in time T_o till a point in time TN , where To is obtained as point in time Ti when a first PDCP PDUi of the UL burst has been received m inus "UL DU delivery time" lastly reported by a DU associated with the first PDCP PDUi, and in the point in time Ti starting a timer TN₁ which is equal to "Average time difference between two consequent UL RLC SDUs" related to the given 5QI/DRB of the UE, lastly reported by the DU.

I n case a next PDCP PDU2 of the UL burst is received in a point in time T₂ while the timer TN1 is running, counting the burst duration is continued, and in T₂ a timer TN₂ which is equal to "Average time difference between two consequent UL RLC SDUs" lastly reported by a DU associated with the next PDCP PDU2 is started.

This procedure is repeated until a PDCP PDUN+ I has been received after a timer TN_N expired, and the end of the UL burst is evaluated as T_N* = T_N - "UL DU delivery time", where TN is a point in time when a PDCP PDUN of the UL burst has been received, and "UL DU delivery time" represents the lastly reported value from the DU associated with PDCP PDUN, related to the given 5QI/DRB of the UE.

The contribution of this UL burst to the total ThpTimeUL is then given as TN

- To. The PDCP PDU N+ 1 represents start of a new UL burst related to the given 5QI/DRB of the UE and all the above procedure is repeated to count the duration of the new UL burst for the intention of the Scheduled I P throughput in UL.

An example for measuring Scheduled I P Throughput for one DU will be described in more detail with reference to Fig. 3 later on.

I n case of UL CA and/or NR Dual Connectivity (DC) with transm ission in UL over more than one DU for the UE and given 5QI/DRB, the above-described procedure is repeated and similar algorithm is applied, where for "UL DU delivery time" and "Average time difference between two UL RLC SDUs" lastly reported values related to the DU associated with the given PDCP PDU are considered. An example for measuring Scheduled I P Throughput for two Dlls will be described in more detail with reference to Fig. 4 later on.

The "UL DU delivery time" represents an averaged UL delay measured at the DU for the concerned 5QI/DRB over Uu interface. The "Average time difference between two consequent UL RLC SDUs" represents an averaged time interval between two consecutive UL RLC SDUs for the given 5QI/DRB and UE without empty buffer (BSR> 0).

The volume of the UL burst related to the given 5QI/DRB of the UE for the intention of the Scheduled I P throughput in UL is counted as sum of the volume of all PDCP SDUs received for the burst, which are associated with the received PDCP PDUs, i.e. Vol (PDCP SDUi + PDCP SDU₂ + ...+ PDCP SDUN) .

At the end of the observation interval the total volume is obtained as sum of volume of all bursts of all UEs related to the given 5QI , total time is obtained as sum of all burst durations of all UEs related to the given 5QI , and Scheduled I P throughput in UL for the given 5QI is obtained as total volume divided by total time, which represents the averaged Scheduled I P throughput in UL per UE and given 5QI .

It is noted that the "UL DU delivery time" is at the beginning of the burst subtracted from the point in time Ti when the first PDCP PDUi has been received, and at the end of the burst the same is done when in the point in time TN the PDCP PDUN has been received. As the contribution of the burst to the total ThpTimeUL which is given as TN - T_o it can be simplified (simplified method) to TN - T? if "UL DU delivery time" can be characterised as random variable with standard deviation STD(UL DU delivery time) < < mean value MEAN(UL DU delivery time) .

I n the following, calculation of UL burst duration for the intention of Scheduled I P throughput in UL according to at least some example embodiments is demonstrated using Fig. 3. According to the example illustrated in Fig. 3, transm ission of UL user data for a given bearer is done via one DU only.

Fig. 3 shows a distribution unit DU- 1 of a base station of a radio access network. The DU- 1 comprises a physical layer "PHY", a MAC layer and an RLC layer.

Fig. 3 also shows a control unit CU-UP of the base station, which comprises PDCP layers PDCP-PDU and PDCP-SDU. Ng denotes an interface between the base station (e.g. gNB) and a core network.

The DU- 1 reports a UL DU delivery time and an average time difference between two consecutive UL RLC SDUs per UE and 5QI/DRB for DU to the CU-UP via an F1 -U interface, e.g. as described above with reference to Fig. 2.

Further, the CU-UP receives PDUs associated with bursts of data received by the DU- 1 from UEs.

At a time T1 , a first PDCP PDU1 has been received at the CU-UP for a burst (UL burst) associated with a UE, and a timer TN1 equal to an average time difference between two consecutive UL RLC SDUs lastly reported by the DU- 1 which is associated with the burst is started. Further, the point in time T1 indicates transition of UE buffer status from "empty" to "non-empty", as calculated at the CU-UP.

The received first PDCP PDU1 is associated with a first PDCP SDU1 received for the burst.

During the time period TN1 , a next PDCP PDU2 for the burst of the UE has been received at a point in time T2. Thus, at T2, a timer TN2 equal to lastly reported average time difference between two consecutive UL RLC SDUs is started.

The received PDCP PDU2 is associated with a PDCP SDU2 received for the burst.

The above process is repeated until a point in time T6. I n other words, since a further PDCP PDU7 was received after time period TN6 expired, end of the burst is detected at point in time T6. Further, the point in time T6 indicates transition of UE buffer status from "non-empty" to "empty", as calculated at the CU-UP.

The PDCP PDU7 represents a first PDCP PDU of a new burst of the UE. Thus, the above process is started for the new burst at T7, and the buffer status of the UE, as calculated at the CU-UP, transitions from "empty" to "nonempty".

The throughput time UL "ThpTimeUL" (burst duration) is measured from TO to T6* , where TO is calculated by subtracting the lastly reported UL DU delivery time from T1 , and T6* is calculated by subtracting the lastly reported UL DU delivery time from T6.

Fig. 4 illustrates an example of calculation of UL burst duration for the intention of Scheduled I P throughput in UL according to at least some example embodiments, where transm ission of UL user data for a given bearer is done via two DUs.

I n addition to the control unit CU-UP and the distribution unit DU- 1 , Fig. 4 shows a distribution unit DU-2 of the base station. The DU-2 comprises the physical layer "PHY", the MAC layer and the RLC layer. The DU- 1 reports a UL DU delivery time and an average time difference between two consecutive UL RLC SDUs per UE and 5QI/DRB for DU-1 to the CU-UP via F1 -U interface.

Sim ilarly, the DU-2 reports a UL DU delivery time and an average time difference between two consecutive UL RLC SDUs per UE and 5QI/DRB for DU-2 to the CU-UP via F1 -U interface.

Further, the DU- 1 and the DU-2 receive bursts of data which are associated with PDUs received at the CU-UP. I n Fig. 4, DU- 1 is associated with PDU1 , PDU3, PDU5 and PDU 7, and DU-2 is associated with PDU2, PDU4 and PDU6.

At a time T1 , a first PDCP PDU1 has been received at the CU-UP for a burst (UL burst) of a UE received by the DU- 1 , and a timer TN1 equal to an average time difference between two consecutive UL RLC SDUs lastly reported from DU- 1 is started. Further, the point in time T1 indicates transition of UE buffer status from "empty" to "non-empty", as calculated at the CU-UP.

During the time period TN1 , a next PDCP PDU2 of the burst of the UE has been received at a point in time T2. The PDCP PDU2 is associated with RLC SDUs for the burst received at the DU-2. Thus, at T2, a timer TN2 equal to an average time difference between two consecutive UL RLC SDUs lastly reported from DU-2 is started.

The received PDCP PDU2 is associated with a PDCP SDU2 received for the burst. The above process is repeated until a point in time T6. I n other words, since a further PDCP PDU7 was received after time period TN6 expired, end of the burst is detected at point in time T6. Further, the point in time T6 indicates transition of UE buffer status from "non-empty" to "empty", as calculated at the CU-UP.

The PDCP PDU7 represents a first PDCP PDU of a new burst associated with the UE. Thus, the above process is started for the new burst at T7, and the buffer status of the UE, as calculated at the CU-UP, transitions from "empty" to "non-empty".

The throughput time UL "ThpTimeUL" (burst duration) is measured from TO to T6* , where TO is calculated by subtracting UL DU delivery time lastly reported by DU- 1 from T1 , and T6* is calculated by subtracting the UL DU delivery time lastly reported by DU-2 from T6.

As described above, according to at least some example embodiments, the principle of measurement of the duration of the UL burst related to the given 5QI/DRB of the UE for the intention of the Scheduled I P throughput in UL is based on reporting of the "UL DU delivery time" and "Average time difference between two consequent UL RLC SDUs" from the related DU to CU-UP via F1 -U interface.

Since a massive and frequent F1 -U message exchange between the DU and CU-UP is not feasible at least some example embodiments rely on an averaged value of "UL DU delivery time" and on "Average time difference between two consequent UL RLC SDUs". It is preferable to com m unicate "UL DU delivery time" and "Average time difference between two consequent UL RLC SDUs" per a configurable time interval (e.g. hundreds of ms) from DU to CU-UP via F1 -U interface or if the value in percentage compared to previously reported value has changed more than a preconfigured threshold. The F1 -U message exchange can be thus decreased to a reasonable number of messages per bearer per measurement period (e.g. 15 minutes as a default) considering hundreds of ms as pre-configured time interval.

According to at least some example embodiments, the "UL DU delivery time" is equivalent to "UL Delay DU Result" defined in 3GPP TS 38.425, chapter 5.5.3.48, which is reported as part of "ASSISTANCE I NFORMATION DATA (PDU Type 2)" from DU to CU-UP, chapter 5.5.2.3 of the same specification.

According to at least some example embodiments, for the "Average time difference between two consequent UL RLC SDUs" there are at least two alternatives of how to obtain it. First one is based on complete new field within the "ASSISTANCE I NFORMATI ON DATA (PDU Type 2)", chapter 5.5.2.3 of the 3GPP TS 38.425. The second option is to have it as implementation specific considering each vendor will implement it as a new field in the proprietary interface between DU and CU-UP.

At least some example embodiments have impact on 3GPP TS 38.314 where the new measurement related to Scheduled I P Throughput in UL is proposed to be defined as follows:

4.2.1 .2.x Scheduled I P Throughput in the UL per QoS group

The objective of this measurement is to measure Scheduled I P Throughput in UL for GAM performance observability or for QoS verification of MDT or for the QoS monitoring.

Protocol Layer: PDCP, RLC, MAC

Table 4.2.1 .2.x- 1 : Definition for Scheduled I P Throughput in the UL per QoS group

Table 4.2.1 ,2.x- 2: Parameter description for Scheduled I P Throughput in the UL per QoS group

It is noted that, according to at least some example embodiments, time t1 in Table 4.2.1 ,2.x-2 corresponds to the second point in time T6* in Figs. 3 and 4.

Further, according to at least some example embodiments, time t2 in Table 4.2.1 ,2.x-2 corresponds to the first point in time TO in Figs. 3 and 4.

Fig. 5 illustrates measurement for Scheduled I P Throughput in UL per QoS group according to at least some example embodiments. Fig. 5 is sim ilar to Fig. 3, where time t2 in Fig. 5 corresponds to time TO in Fig. 3 and time t1 in Fig. 5 corresponds to time T6* in Fig. 3. The procedure of calculating burst durations illustrated by Fig. 5 corresponds to that described above with reference to Fig. 3.

According to at least some example embodiments, on one side, the logic of Scheduled I P Throughput in UL in 5G is kept in a sim ilar manner as in E- UTRAN and, on the other side, some extra messaging on F1 -U interface is kept on m inim um possible level. Regarding the com munication of "UL DU delivery time" and "Average time difference between two UL RLC SDUs" as an average value per a configurable time interval (e.g. hundreds of ms) from DU to CU-UP via F1 -U interface and not per each two consecutive RLC SDUs following the logic how Scheduled I P throughput is defined, which is also an averaged throughput, it shall not impact the precision of the obtained throughput values using the method according to at least some example embodiments.

Now reference is made to Fig. 6 illustrating simplified block diagrams of a control unit 610 and a distribution unit 620, that are suitable for use in practicing at least some example embodiments. According to an implementation example, process 1 is implemented by the control unit 610 and process 2 is implemented by the distribution unit 620.

The control unit 610 comprises processing resources (e.g. processing circuitry) 61 1 , memory resources (e.g. memory circuitry) 612 and interfaces (e.g. interface circuitry) 613, which are coupled via a wired or wireless connection 614.

The distribution unit 620 comprises processing resources (e.g. processing circuitry) 621 , memory resources (e.g. memory circuitry) 622 and interfaces (e.g. interface circuitry) 623, which are coupled via a wired or wireless connection 624. The control unit 610 and the distribution unit 620 are connected via an interface 630 which is, for example, an F1 -U interface.

According to an example implementation, the memory resources 612, 622 are of any type suitable to the local technical environment and are implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The processing resources 61 1 , 621 are of any type suitable to the local technical environment, and include one or more of general purpose computers, special purpose computers, m icroprocessors, digital signal processors (DSPs) and processors based on a m ulti core processor architecture, as non-lim iting examples.

According to an implementation example, the memory resources 612, 622 comprise one or more non-transitory computer-readable storage media which store one or more programs that when executed by the processing resources 61 1 , 621 cause the control unit 610 / the distribution unit 620 to function as CU-UP / DU- 1 , DU-2 as described above.

Further, as used in this application, the term "circuitry" refers to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) to combinations of circuits and software (and/or firmware) , such as (as applicable) : (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)) , software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) to circuits, such as a m icroprocessor(s) or a portion of a microprocessor(s) , that require software or firmware for operation, even if the software or firmware is not physically present. This definition of "circuitry" applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or m ultiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a sim ilar integrated circuit in server, a cellular network device, or other network device.

Experiments

Some sim ulations were executed to confirm the reliability and correctness of the simplified method according to at least some example embodiments proposed to identify time intervals with data in the buffer in CU-UP as follows:

1 . I n the first step the BSR on MAC level of DU per DRB and UE as a random variable as function of time on time interval 0.5 second was generated. For simplification the state with data in the buffer was represented by BSR value equal to 1 , while empty buffer with BSR equal to 0.

2. I n the second step slots when PDCP PDU received for the DRB and UE in CU-UP from DU as a random variable as function of time on time interval 0.5 second was generated. For simplification the volume of each PDCP PDU was considered to be the same and equal to 1 kbit. The slot duration was also considered to be constant and equal to 1 ms.

3. True value of Scheduled I P Throughput for the DRB and UE was calculated.

4. As a next step "Average time difference between two UL RLC SDUs" was calculated based on above points 1 and 2.

5. ThpTimeUL was obtained using the method according to at least some example embodiments as described above with reference to Figs. 2 to 5. 6. Based on above points 2 and 5, the value of Scheduled I P Throughput for the DRB and UE which is a value based on the method according to at least some example embodiments was calculated.

Fig. 7 shows the BSR on MAC level of DU per DRB and UE generated as a random variable as function of time as per above point 1 .

The true value of Scheduled I P Throughput for the DRB and UE calculated was equal to 492 kbps.

"Average time difference between two UL RLC SDUs" calculated based on above points 1 and 2 was equal to 2.03 ms.

I n Fig. 8 the BSR per DRB and UE obtained based on the method according to at least some example embodiments is shown.

Fig. 9 shows the difference between the curves of Figs. 7 and 8 with a trend line which is close to 0.

The value of Scheduled I P Throughput for the DRB and UE calculated based on the method according to at least some example embodiments was equal to 500 kbps, considering a relative error in the obtained results equal to 100* (492 - 500)/492 = 1 .6 % .

The sim ulation was repeated may times to generate different random variables as per above point 1 with the relative error in the obtained results not exceeding 3.5 % .

Conclusions from Experiments

As can be seen from graphs in Figs. 7 and 8, the BSR per DRB and UE in CU-UP obtained based on the method according to at least some example embodiments does not follow exactly the BSR function on MAC level in DU. This is an expected observation as "Average time difference between two UL RLC SDUs" is not reported per each two consecutive RLC SDUs but as an average value per a configurable time interval (e.g. hundreds of ms, in this experiment 500 ms) from DU to CU-UP. On the other hand, results using the method according to at least some example embodiments were obtained with the relative error not exceeding 3.5 % . This is fully in line with the following conclusion:

"Regarding the com m unication of the "Average time difference between two UL RLC SDUs" as an average value per a configurable time interval (e.g. hundreds of ms) from DU to CU-UP via F1 -U interface and per each two consecutive RLC SDUs following the logic how Scheduled I P throughput is defined, which is also an averaged throughput, it shall not impact the precision of the obtained throughput values using the method according to at least some example embodiments."

The method according to at least some example embodiments is beneficial, because it keeps the logic of Scheduled I P Throughput in UL in 5G in the similar manner as in E-UTRAN on one side and it also keeps some extra message needed for this method on F1 -U interface on minim um possible level.

According to at least some example embodiments, an apparatus for use by a control unit of a base station of a radio access network is provided. The apparatus comprises: means for receiving, from at least one distribution unit, information on a time period; means for receiving protocol data units associated with bursts of data received by the at least one distribution unit from at least one user equipment; means for calculating durations of the bursts based on the protocol data units and based on the time period; and means for calculating, for the at least one user equipment, a scheduled throughput in uplink direction based on the durations of the bursts. According to at least some example embodiments, the scheduled throughput in uplink direction is calculated for the at least one user equipment based on the durations of the bursts and based on a volume of service data units received for the bursts at the control unit.

According to at least some example embodiments, the information on the time period is received with a configurable time interval.

According to at least some example embodiments, the information on the time period is received with a time interval of hundreds of m illiseconds.

According to at least some example embodiments, the time period is an average time difference between two consecutive service data units associated with the bursts at the at least one distribution unit.

According to at least some example embodiments, the time period is related to at least one of service quality and radio bearer of the at least one user equipment.

According to at least some example embodiments, the means for calculating the durations of the bursts comprises: means for measuring a duration of a burst of the bursts, from a first point in time until a second point in time, by: obtaining the first point in time as a time T1 at which a first protocol data unit PDU1 of the burst has been received at the control unit, starting, at the time T1 , a timer TN1 which is equal to the time period lastly received from the at least one distribution unit associated with the first protocol data unit PDU1 , in case a next protocol data unit PDU2 has been received at a time T2 while the timer TN1 is running, continuing counting the duration of the burst and starting, at the time T2, a timer TN2 which is equal to the time period lastly received from the at least one distribution unit associated with the next protocol data unit PDU2, and repeating the continuing of the counting and starting of timer until a protocol data unit PDUN+ 1 has been received after a timer TNN expired, and obtaining the second point in time as a time TN at which a protocol data unit PDUN has been received at the control unit, wherein the protocol data unit PDUN+ 1 represents start of a new burst of the bursts, and duration of the new burst is measured from first point in time until second point in time.

According to at least some example embodiments, the apparatus further comprises means for receiving, from the at least one distribution unit, information on an uplink delivery time, wherein the first point in time is obtained by subtracting, from the time T1 , the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDU1 , and wherein the second point in time is obtained by subtracting, from the time TN, the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDUN.

According to at least some example embodiments, the information on the uplink delivery time is received with a configurable time interval. According to at least some example embodiments, the information on the uplink delivery time is received with a time interval of hundreds of milliseconds.

According to at least some example embodiments, the information on the uplink delivery time is received if a value of the uplink delivery time has changed more than a predeterm ined threshold.

According to at least some example embodiments, the means for calculating the scheduled throughput comprises means for, at the end of an observation interval: obtaining a total volume as a sum of volumes of the bursts of the at least one user equipment related to a given quality of service identifier, obtaining a total time as a sum of the burst durations of the at least one user equipment related to the given quality of service identifier, and obtaining the scheduled throughput in the uplink direction for the given quality of service identifier as an averaged scheduled throughput in the uplink direction per user equipment and given quality of service identifier by dividing the total volume by the total time.

According to at least some example embodiments, an apparatus for use by a distribution unit of a base station of a radio access network is provided. The apparatus comprises: means for calculating an average time difference between two consecutive service data units associated with bursts of data received from at least one user equipment as a time period; and means for reporting, to a control unit, information on the time period, wherein the control unit receives packet data units associated with the bursts.

According to at least some example embodiments, the information on the time period is transm itted with a configurable time interval. According to at least some example embodiments, the information on the time period is transmitted with a time interval of hundreds of m illiseconds.

According to at least some example embodiments, the apparatus further comprises: means for transm itting, to the control unit, information on an uplink delivery time.

According to at least some example embodiments, the information on the uplink delivery time is transmitted with a configurable time interval.

According to at least some example embodiments, the information on the uplink delivery time is transmitted with a time interval of hundreds of m i II iseconds.

According to at least some example embodiments, the apparatus further comprises: means for measuring, as the uplink delivery time, an averaged uplink delay for a radio bearer associated with the bursts. According to at least some example embodiments, the radio access network complies with 5G.

According to at least some example embodiments, the control unit resides on user plane.

According to at least some example embodiments, the control unit comprises a packet data configuration protocol, PDCP, layer.

According to at least some example embodiments, the distribution unit comprises a medium access control, MAC, layer and a radio link control, RLC, layer.

According to at least some example embodiments, the scheduled throughput is a scheduled internet protocol, I P, throughput. It is to be understood that the above description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

Claims

CLAI MS

1 . A method for use by a control unit of a base station of a radio access network, the method comprising: receiving, from at least one distribution unit, information on a time period; receiving protocol data units associated with bursts of data received by the at least one distribution unit from at least one user equipment; calculating durations of the bursts based on the protocol data units and based on the time period; and calculating, for the at least one user equipment, a scheduled throughput in uplink direction based on the durations of the bursts.

2. The method of claim 1 , wherein the scheduled throughput in uplink direction is calculated for the at least one user equipment based on the durations of the bursts and based on a volume of service data units received for the bursts at the control unit.

3. The method of claim 1 or 2, wherein at least one of the following: the information on the time period is received with a configurable time interval, the information on the time period is received with a time interval of hundreds of m illiseconds, the information on the time period is received if a value of the time period has changed more than a predeterm ined threshold.

4. The method of any one of claims 1 to 3, wherein the time period is an average time difference between two consecutive service data units associated with the bursts at the at least one distribution unit.

5. The method of any one of claims 1 to 4, wherein the time period is related to at least one of service quality and radio bearer of the at least one user equipment.

6. The method of any one of claims 1 to 5, wherein the calculating the durations of the bursts comprises: measuring a duration of a burst of the bursts, from a first point in time until a second point in time, by: obtaining the first point in time as a time T1 at which a first protocol data unit PDU1 of the burst has been received at the control unit, starting, at the time T1 , a timer TN1 which is equal to the time period lastly received from the at least one distribution unit associated with the first protocol data unit PDU1 , in case a next protocol data unit PDU2 has been received at a time T2 while the timer TN1 is running, continuing counting the duration of the burst and starting, at the time T2, a timer TN2 which is equal to the time period lastly received from the at least one distribution unit associated with the next protocol data unit PDU2, and repeating the continuing of the counting and starting of timer until a protocol data unit PDUN+ 1 has been received after a timer TNN expired, and obtaining the second point in time as a time TN at which a protocol data unit PDUN has been received at the control unit, wherein the protocol data unit PDUN+ 1 represents start of a new burst of the bursts, and duration of the new burst is measured from first point in time until second point in time.

7. The method of claim 6, comprising: receiving, from the at least one distribution unit, information on an uplink delivery time, wherein the first point in time is obtained by subtracting, from the time T1 , the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDU1 , and wherein the second point in time is obtained by subtracting, from the time TN, the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDUN.

8. The method of claim 7, wherein at least one of the following: the uplink delivery time is related to at least one of service quality and radio bearer of the at least one user equipment, the uplink delivery time represents an averaged uplink delay measured at the distribution unit for a radio bearer associated with the bursts, the information on the uplink delivery time is received with a configurable time interval, the information on the uplink delivery time is received with a time interval of hundreds of m illiseconds, the information on the uplink delivery time is received if a value of the uplink delivery time has changed more than a predetermined threshold.

9. The method of any one of claims 1 to 8, the calculating the scheduled throughput comprising, at the end of an observation interval: obtaining a total volume as a sum of volumes of the bursts of the at least one user equipment related to a given quality of service identifier, obtaining a total time as a sum of the burst durations of the at least one user equipment related to the given quality of service identifier, and obtaining the scheduled throughput in the uplink direction for the given quality of service identifier as an averaged scheduled throughput in the uplink direction per user equipment and given quality of service identifier by dividing the total volume by the total time.

10. A method for use by a distribution unit of a base station of a radio access network, the method comprising: calculating an average time difference between two consecutive service data units associated with bursts of data received from at least one user equipment as a time period; and reporting, to a control unit, information on the time period, wherein the control unit receives packet data units associated with the bursts.

1 1 . The method of claim 10, wherein at least one of the following: the information on the time period is transmitted with a configurable time interval, the information on the time period is transmitted with a time interval of hundreds of m illiseconds, the information on the time period is transmitted if a value of the time period has changed more than a predeterm ined threshold.

12. The method of claim 10 or 1 1 , further comprising: transm itting, to the control unit, information on an uplink delivery time, wherein at least one of the following: the uplink delivery time is related to at least one of service quality and radio bearer of the at least one user equipment, the information on the uplink delivery time is transm itted with a configurable time interval, the information on the uplink delivery time is transm itted with a time interval of hundreds of m illiseconds, the information on the uplink delivery time is transm itted if a value of the uplink delivery time has changed more than a predetermined threshold.

13. The method of claim 12, further comprising: measuring, as the uplink delivery time, an averaged uplink delay for a radio bearer associated with the bursts.

14. The method of any one of claims 1 to 13, wherein at least one of the following: the radio access network complies with 5G; the control unit resides on user plane; the control unit comprises a packet data configuration protocol, PDCP, layer; the distribution unit comprises a medium access control, MAC, layer and a radio link control, RLC, layer; the information on at least one of the time period and the uplink delivery time is com m unicated via an F1 -U interface; the protocol data units are PDCP protocol data units; the service data units associated with the bursts at the at least one distribution unit are uplink RLC service data units; the service data units received for the bursts at the control unit are PDCP service data units; the volumes of the bursts are volumes of PDCP service data units received for the bursts; the scheduled throughput is a scheduled internet protocol, I P, throughput.

15. A non-transitory computer-readable storage medium storing a program that, when executed by a control unit of a base station of a radio access network, causes the control unit at least to: receive, from at least one distribution unit, information on a time period; receive protocol data units associated with bursts of data received by the at least one distribution unit from at least one user equipment; calculate durations of the bursts based on the protocol data units and based on the time period; and calculate, for the at least one user equipment, a scheduled throughput in uplink direction based on the durations of the bursts.

16. A non-transitory computer-readable storage medium storing a program that, when executed by a distribution unit of a base station of a radio access network, causes the distribution unit at least to: calculate an average time difference between two consecutive service data units associated with bursts of data received from at least one user equipment as a time period; and report, to a control unit, information on the time period, wherein the control unit receives packet data units associated with the bursts.

17. An apparatus for use by a control unit of a base station of a radio access network, the apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive, from at least one distribution unit, information on a time period; receive protocol data units associated with bursts of data received by the at least one distribution unit from at least one user equipment; calculate durations of the bursts based on the protocol data units and based on the time period; and calculate, for the at least one user equipment, a scheduled throughput in uplink direction based on the durations of the bursts.

18. The apparatus of claim 17, wherein the scheduled throughput in uplink direction is calculated for the at least one user equipment based on the durations of the bursts and based on a volume of service data units received for the bursts at the control unit.

19. The apparatus of claim 17 or 18, wherein at least one of the following: the information on the time period is received with a configurable time interval, the information on the time period is received with a time interval of hundreds of m illiseconds, the information on the time period is received if a value of the time period has changed more than a predeterm ined threshold.

20. The apparatus of any one of claims 17 to 19, wherein the time period is an average time difference between two consecutive service data units associated with the bursts at the at least one distribution unit.

21 . The apparatus of any one of claims 17 to 20, wherein the time period is related to at least one of service quality and radio bearer of the at least one user equipment.

22. The apparatus of any one of claims 17 to 21 , wherein to calculate the durations of the bursts the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus further to: measure a duration of a burst of the bursts, from a first point in time until a second point in time, by: obtaining the first point in time as a time T1 at which a first protocol data unit PDU1 of the burst has been received at the control unit, starting, at the time T1 , a timer TN1 which is equal to the time period lastly received from the at least one distribution unit associated with the first protocol data unit PDU1 , in case a next protocol data unit PDU2 has been received at a time T2 while the timer TN1 is running, continuing counting the duration of the burst and starting, at the time T2, a timer TN2 which is equal to the time period lastly received from the at least one distribution unit associated with the next protocol data unit PDU2, and repeating the continuing of the counting and starting of timer until a protocol data unit PDUN+ 1 has been received after a timer TNN expired, and obtaining the second point in time as a time TN at which a protocol data unit PDUN has been received at the control unit, wherein the protocol data unit PDUN+ 1 represents start of a new burst of the bursts, and duration of the new burst is measured from first point in time until second point in time.

23. The apparatus of claim 22, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus further to: receive, from the at least one distribution unit, information on an uplink delivery time, wherein the first point in time is obtained by subtracting, from the time T1 , the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDU1 , and wherein the second point in time is obtained by subtracting, from the time TN, the uplink delivery time lastly received from the at least one distribution unit associated with the protocol data unit PDUN.

24. The apparatus of claim 23, wherein at least one of the following: the uplink delivery time is related to at least one of service quality and radio bearer of the at least one user equipment, the uplink delivery time represents an averaged uplink delay measured at the distribution unit for a radio bearer associated with the bursts, the information on the uplink delivery time is received with a configurable time interval, the information on the uplink delivery time is received with a time interval of hundreds of m illiseconds, the information on the uplink delivery time is received if a value of the uplink delivery time has changed more than a predetermined threshold.

25. The apparatus of any one of claims 17 to 24, wherein to calculate the scheduled throughput at the end of an observation interval the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus further to: obtain a total volume as a sum of volumes of the bursts of the at least one user equipment related to a given quality of service identifier, obtain a total time as a sum of the burst durations of the at least one user equipment related to the given quality of service identifier, and obtain the scheduled throughput in the uplink direction for the given quality of service identifier as an averaged scheduled throughput in the uplink direction per user equipment and given quality of service identifier by dividing the total volume by the total time.

26. An apparatus for use by a distribution unit of a base station of a radio access network, the apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: calculate an average time difference between two consecutive service data units associated with bursts of data received from at least one user equipment as a time period; and report, to a control unit, information on the time period, wherein the control unit receives packet data units associated with the bursts.

27. The apparatus of claim 26, wherein at least one of the following: the information on the time period is transmitted with a configurable time interval, the information on the time period is transmitted with a time interval of hundreds of m illiseconds, the information on the time period is transmitted if a value of the time period has changed more than a predeterm ined threshold.

28. The apparatus of claim 26 or 27, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus further to: transm it, to the control unit, information on an uplink delivery time, wherein at least one of the following: the uplink delivery time is related to at least one of service quality and radio bearer of the at least one user equipment, the information on the uplink delivery time is transm itted with a configurable time interval, the information on the uplink delivery time is transm itted with a time interval of hundreds of m illiseconds, the information on the uplink delivery time is transm itted if a value of the uplink delivery time has changed more than a predetermined threshold.

29. The apparatus of claim 28, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus further to: measure, as the uplink delivery time, an averaged uplink delay for a radio bearer associated with the bursts.

30. The apparatus of any one of claims 17 to 29, wherein at least one of the following: the radio access network complies with 5G; the control unit resides on user plane; the control unit comprises a packet data configuration protocol, PDCP, layer; the distribution unit comprises a medium access control, MAC, layer and a radio link control, RLC, layer; the information on at least one of the time period and the uplink delivery time is com m unicated via an F1 -U interface; the protocol data units are PDCP protocol data units; the service data units associated with the bursts at the at least one distribution unit are uplink RLC service data units; the service data units received for the bursts at the control unit are PDCP service data units; the volumes of the bursts are volumes of PDCP service data units received for the bursts; the scheduled throughput is a scheduled internet protocol, I P, throughput.