KR20070097443A - Apparatus and method in a cellular network - Google Patents

Abstract

A node (5) for use in a cellular network (4) to control the transmission of data from a radio base station (3) in the cellular network to a mobile terminal (1), is proposed, said node (5) comprising memory (7) for storing a channel quality value reported by the mobile terminal, and acknowledgement messages received from the mobile terminal, and calculating means (9) for calculating an adjustment value for the channel quality value based on the acknowledgement messages. The calculating means (9) is arranged to calculate said adjustment value for the perceived channel quality value taking into account at least two responses related to at least two blocks, and calculate said adjusted value using the adjustment value. The evaluation may be based on consecutive acknowledgement messages or on statistics derived from a plurality of messages.

Description

Apparatus and method in a cellular network {APPARATUS AND METHOD IN A CELLULAR NETWORK}

The present invention relates to an apparatus and method according to the full text of each of the independent claims 1 and 9 and to a computer program product according to the full text of the independent claim 18.

For communication in a cellular communication system, it is important to control the user and transport data formats to be scheduled in order to optimize throughput in the network.

In many cellular communication systems, the mobile terminal reports the received channel quality to the base station. This channel quality is used for scheduling, determining the amount of data that can be sent to the mobile terminal at a given time, and possibly for other purposes.

For example, in accordance with the 3GPP standard for WCDMA High Speed Downlink Packet Access (HSDPA), a mobile station reports a channel quality indicator (CQI) to a wireless base station, which reflects the channel quality sensed by the mobile station. CQI is an information element included in related uplink signaling. The CQI reported by the mobile station reflects the receiver performance capabilities of the UE and is reported at a predetermined rate and average interval defined by the network and based on the measurements of the CPICH.

A CQI, such as an integer between 0 and 30, is reported, where 0 indicates that the mobile terminal is not ready to be scheduled and that no transmission should be made to the mobile terminal. Among other things, based on the CQI, the base station will perform scheduling, i.e., select the mobile station for transmission, and also select the transport block format, i.e. the amount of data to be transmitted, and use it for transmission to this mobile terminal. .

The 3G standard specifies that a mobile terminal must report a CQI that results in a hybrid automatic repeat request (HARQ) block error rate (BLER) of 10%, which means that the mobile terminal cannot decode 10% of transmissions on average.

The 3GPP standard also specifies the requirements for CQI reporting accuracy for mobile terminals, but it is expected that the actual reporting accuracy will be altered to the mobile terminal model. If a mobile terminal reports an inaccurate CQI, the base station may choose to use its scheduling and transport block format for faulty data resulting in lower throughput due to less efficient use of the high speed downlink shared channel (HS-DSCH). Will be based on. In particular, some mobile terminals tend to overestimate their reception quality. These terminals will be scheduled for transmission more often than if their CQI is correct. Also, since the transmission will not be adapted to the actual performance of the terminal to receive the data, a large number of blocks will not be received correctly. These blocks will be retransmitted, resulting in low throughput. In the worst case, the block error rate (BLER) can reach 100%. Conversely, mobile terminals that underestimate their mobile terminal capabilities by sending very low CQI should exhibit a BLER lower than 10% due to very conservative TB selection by the wireless network and will not be scheduled every time.

Therefore, in order to minimize the traffic of the network from an overall perspective, if the network is reported incorrectly by the terminal itself, it will be necessary to adjust the CQI reported by the mobile terminal.

One known algorithm for adjusting CQI is based on ACK (acknowledge) and NACK (negative acknowledgment) messages received from the mobile terminal. In this algorithm, if a NACK message is received indicating that the transmission of data was not correctly received at the mobile terminal, the CQI is reduced while the CQI is increased to the same or different value for each ACK message.

The WCDMA standard defines a number of parameters that can be used to adjust how often a mobile terminal reports its CQI.

It is an object of the present invention to provide a method and apparatus for adjusting the CQI reported from a mobile terminal to optimize the efficiency and throughput of the system.

The present invention achieves this by using a node used in the cellular network to control data transmission from the wireless base station in the cellular network to the mobile terminal, which node senses channel quality values reported by the mobile terminal, and Means for storing acknowledgment and negative acknowledgment messages received from the mobile terminal in response to the data block transmitted from the wireless base station to the mobile terminal; A computing means for calculating, the memory is also arranged to store a adjusted value for the sensed channel quality value, wherein the node is configured to sense the channel for which the computing means considers two or more responses with respect to two or more blocks. Calculate the adjustment value for the quality value and use the adjustment value W is characterized in that is arranged to calculate said adjusted value.

The object is also to achieve a method used in the network to adjust the sensed channel quality value reported by the mobile terminal to a wireless base station transmitting a block of data to the mobile terminal, wherein the mobile terminal is responsible for the transmission of data transmitted to the mobile terminal. For each block, respond with an acknowledgment message indicating that the block was received correctly or with a negative acknowledgment message indicating that the block was received incorrectly.

Monitoring two or more responses corresponding to two or more blocks of data transmitted to the mobile terminal,

Determining based on the two or more responses whether or not the sensed channel quality value should be adjusted; And

And adjusting the sensed channel quality value as determined.

The object is also achieved by a computer program product comprising program code which, when operating at a node associated with a wireless base station in a mobile telecommunications network, causes the node to carry out the inventive method.

In this way, if the session begins with a negative response, the channel quality value is avoided in a hurry, and conversely the algorithm adjusts the detected channel quality value up one level long before the decision can be based on voice data. I never do that. Therefore, the inventive algorithm is unlikely to adjust the sensed channel quality value that already accurately reflects the performance of the terminal in order to receive the data. In a WCDMA system, the sensed channel quality value will be CQI and the acknowledgment and negative messages will be ACK and NACK, respectively. The method and apparatus of the invention can be used in any cellular network where the estimated channel quality is reported from the mobile terminal to the network.

In a first preferred embodiment, the calculating means is arranged to reduce the sensed channel quality value by a predetermined amount if the two or more responses comprise two or more consecutive negative responses.

In this first preferred embodiment, the calculation means is also, or alternatively arranged to increase the sensed channel quality value by a predetermined amount if the two or more responses comprise two or more consecutive acknowledgments. .

Preferably, consecutive blocks of data transmitted to the mobile terminal may be considered.

The invented method of adjusting the CQI value results in early adjustment of the CQI, as reported by the mobile terminal even for small payloads. In addition, since this adjustment algorithm is adapted to adjusting a small amount of data, it can be done early if the mobile terminal exhibits deviating reporting characteristics. This is important because a lot of traffic in the network is likely to consist of small objects that do not generate enough ACKs and NACKs to infer reliable statistics.

For example, the predetermined number of consecutive negative acknowledgments can be set to two, and the predetermined number of consecutive negative acknowledgments can be set to ten.

In a second preferred embodiment, the memory collects data from a sufficient number of data blocks to determine the percentage of acknowledgments and negative acknowledgments, and said calculating means if the number of negative acknowledgments indicates a block error rate higher than a predetermined threshold rate. If the detected channel quality value is reduced and the number of acknowledgments indicates a block error rate lower than the sensed threshold rate, then the acknowledgment and / or negative response is arranged in a manner that increases the sensed channel quality value.

In this second preferred embodiment, the method includes collecting data from a predetermined number of data blocks, the predetermined number of blocks being sufficient to determine the percentage of acknowledgments and negative responses, If the number indicates a block error rate higher than the predetermined threshold rate, reduce the sensed channel quality value, and if the number of acknowledgments indicates a block error rate lower than the detected threshold rate, increase the sensed channel quality value.

This algorithm is adapted to large objects transmitted in multiple transport blocks generating ACKs and NACKs sufficient to perform statistical interpretation of the NACK rate, and then form a solid foundation for CQI adjustment for the duration of the session.

In a second preferred embodiment, the predetermined threshold rate may for example correspond to a block error rate of 10%.

According to a third preferred embodiment of the invented node, the memory comprises a first value defining a first measurement interval and the calculation means:

If the two or more responses include two or more consecutive negative responses during the first measurement period, reduce the sensed channel quality value by a predetermined amount, and wherein the two or more responses comprise two or more consecutive acknowledgments. And increase the channel quality value detected after the first measurement interval by a predetermined amount, and after the first measurement period, data from a sufficient number of data blocks to determine the percentage of acknowledgment and negative response. Decrease the detected channel quality value if the number of negative acknowledgments is higher than the predetermined threshold rate and detect the block error rate if the number of acknowledgments is lower than the predetermined threshold rate. Is arranged to increase.

According to a third embodiment, if at least a first measurement interval is defined in the method, and during the first measurement interval, the two or more responses during the first measurement period comprise two or more consecutive negative responses, Reduce the channel quality value detected by the positive amount, and if the two or more responses include two or more consecutive acknowledgments, increase the channel quality value detected after the first measurement interval by a predetermined amount; After the measurement interval, data is collected from a predetermined number of data blocks, the predetermined number of blocks being sufficient to determine the percentage of acknowledgments and negative responses, with a block error rate in which the number of negative responses is higher than a predetermined threshold rate. Decrease the detected channel quality value, and if the number of acknowledgments is lower than the predetermined threshold rate, indicate a block error rate Thereby increasing the quality value.

Using one algorithm for a small amount of data and switching to another algorithm after any amount of data has been transmitted optimizes the cost of the algorithm for data objects of any size.

As used herein, the term "mobile terminal" refers to any kind of end user equipment that can be used to communicate with a cellular network.

1 shows schematically a communication between a mobile telecommunications network and a mobile terminal;

2 is a flow chart of an embodiment of the invention.

1 shows communication between a mobile terminal and a wireless base station 3 of a cellular telecommunications network 4.

Common in the technology, the radio base station 3 transmits data blocks in the downlink direction towards the mobile terminal 1. For each block of data, the mobile terminal 1 determines whether the block is received correctly. If received correctly, the terminal sends an acknowledgment (ACK) to the wireless base station 3. If the block is not received correctly, the terminal sends a negative acknowledgment (NACK) to the wireless base station. The terminal also sends a channel quality indicator (CQI) indicative of the channel quality sensed by the terminal to the wireless base station. CQI information is included in the HS-DPCCH subframe of two or more slots. Those skilled in the art are familiar with the generation and transmission of CQIs.

The radio base station comprises or is connected to the CQI adjusting means 5. The CQI adjusting means comprises a memory 7 which stores a CQI value and ACKs and NACKs received from the terminal. In addition, the CQI adjusting means comprises a calculating means 9, which includes software for calculating an adjusting value which must always be added or subtracted from the CQI value. The computing means may comprise one or more processors. This adjustment value is determined based on the transmission of multiple data blocks to the mobile station, which will be described in detail below. The adjusted CQI value and / or adjustment value is stored in the memory of the CQI adjusting means 5 and can access any function in the base station 3 according to the correct CQI value. The memory 7 also includes any parameters needed to calculate the adjustment value, which will be described later.

Those skilled in the art will recognize that the division in the CQI adjusting means 5 shown in Fig. 1 is a pure function. Memory and computational functions may be performed by the same unit or may be distributed among several units that appear to be suitable. Also, of course, the CQI adjusting means 5 will often be part of a large control unit.

According to the first embodiment of the present invention, for the data block transmitted from the wireless base station to the mobile terminal, the corresponding ACK and NACK returned from the mobile terminal are registered according to the CQI reported from the terminal. In order to avoid very fast changes, let the terminal indicate how well the number of consecutive ACK or NACK messages are received from the wireless base station.

If the number of consecutive NACK messages exceeds the first threshold, this indicates that the terminal's ability to receive data is overestimated. Thereafter the CQI reported from the terminal should be reduced and reflected better than the actual environment. Therefore, if the number of consecutive NACK messages exceeds the first threshold, then the CQI reported by the terminal is reduced to one. If the number of consecutive ACK messages exceeds the second threshold, then the CQI reported from the terminal is increased to reflect the improved performance of the terminal for receiving data.

The first algorithm can be described as follows using the following parameters:

deltaCqi: An adjustment value, that is, a value at which the sensed CQI reported from the mobile terminal should be adjusted.

nackConsecutive: Threshold that defines the number of consecutive negative responses that must reach a reduced control.

ackConsecutive: Threshold that defines the number of consecutive acknowledgments that must reach an increased control value.

If the number of consecutive NACKs≥nackConsecutive, then deltaCqi = deltaCqi-1, and if the number of ACKs≥, then deltaCqi = deltaCqi + 1.

To target the desired BLER, the number of consecutive NACK messages needed to reduce the first threshold nackConsecutive, ie, CQI, must be significantly lower than the second threshold ackConsecutive, which indicates the number of consecutive ACK messages that will cause the CPI to increase. Should be. For example, two consecutive NACK messages may be sufficient to decrease, while successive ACK messages will be needed to increase.

If the number of consecutive NACKs reaches the first threshold, CQI adjustment is initiated and the count of consecutive NACKs is reset to zero. Likewise, if the number of consecutive ACKs reaches the second threshold, the count of consecutive ACKs is reset to zero.

This results in early adjustment of CQI, as reported by the mobile terminal even for small payloads. Therefore, the first embodiment is particularly well suited for the transmission of small amounts of data when the number of blocks to be transmitted is too low to obtain reliable statistical data.

If no ACK or NACK is received at the TTI, the CQI adjustment algorithm is stopped until the next correctly coded ACK or NACK is received.

According to a second embodiment of the invention, which is more suitable for large amounts of data, a measurement interval is determined, which must be long enough for statistical data to be established. In another preferred embodiment, the measurement is performed over a period of 50 TTI. The measurement should probably cover at least 10 TTIs of any significant statistical data. In addition, the measurement interval must be short enough to allow correction of the CQI at reasonable time intervals.

In this second embodiment, the CQI is adjusted up and down based on the average percentage of ACKs and NACKs included in the predetermined measurement interval. If a portion of the NACK at a predetermined interval is higher than the first reset threshold, the CQI will be reduced. If a portion of the NACK is lower than the first reset threshold in a given measurement interval, the CQI will be increased. The predetermined threshold may be the same, but preferably a hysteresis is formed in the adjustment algorithm such that the rate of NACK messages needed to increase the CQI is lower than the rate of NACK messages needed to reduce the CQI.

Therefore, the following four parameters are needed to adjust the CQI adjustment algorithm of the second embodiment:

Measurement interval (expressed as the number of TTIs)

NACK ratio average: nakcAverage = number of NACKs at measurement interval / number of TTIs at measurement interval

deltaCqi: an adjustment value, that is, a value at which the sensed CQI reported from the mobile terminal should be adjusted.

nackNinus: NACK rate threshold to reduce CQI

nackPlus: NACK rate threshold to increase CQI

nackMinus must be greater than nackPlus.

According to the above definition, the algorithm is:

If nackAverage> nackMinus, deltaCqi = deltaCqi-1,

If nackAverage <nackPlus, then deltaCqi = deltaCqi + 1.

For example, if the measurement interval is 20 TTI and 10% of the BLER is desired, the CQI can be reduced if the number of NACKs in the measurement interval is two or more.

If no ACK or NACK is received within the TTI, then the CQI adjustment algorithm is stopped until the next correctly coded ACK or NACK is received.

One skilled in the art can achieve this by determining the ACK number of the measurement interval and setting the threshold for the ACK instead since the number of ACKs is directly related to the number of NACKs.

In addition, there is no need to register ACK or NACK during every TTI. The second algorithm may be used, for example, on an ACK or NACK message from every second TTI.

According to a third preferred embodiment, the first and second embodiments are combined in such a way that during the first TTI the CQI is adjusted according to the first embodiment, and then the CQI is adjusted according to the second embodiment.

The number of TTIs to which the first algorithm should be applied before switching to the second algorithm may be arbitrarily selected. It is advantageous for at least 3-5 TTIs to be covered and a number of about 15 TTIs to be considered.

The adjustment value obtained according to the first algorithm will be used as the input CQI adjustment value when starting to apply the second algorithm. The first algorithm is used as input to the second algorithm, while it must be determined whether accumulated ACKs and NACKs were used. Preferably, in this third embodiment, the ACKs NACKs accumulated while the first algorithm is used will not be used as input data to the second algorithm if the adjustment value is adjusted based on the first algorithm. In this case, if the first algorithm does not reach the adjustment of the CQI, the accumulated ACKs and NACKs can be used as input to the second algorithm. Another option would always use accumulated ACKs and NACKs or never use them.

2 is a flowchart summarizing a method according to the third embodiment.

The following parameters are required:

CQI: CQI value reported by the terminal

Int 1: First measurement interval to which the first method is applied

Int 2: Second measurement interval during second method

Th 1: First threshold for consecutive NACKs in the first measurement interval

Th 2: Second threshold for successive ACKs in second measurement interval

Th 3: First NACK Rate Threshold for Number of NACKs in Second Measurement Interval

Th 4: Second NACK ratio threshold for the number of NACKs in the first measurement interval.

Steps S1 to S5 reflect the first algorithm used for the first measurement interval. Steps S7 through S12 reflect the second algorithm used in the second measurement interval. Step S6 reflects the transition point from the first algorithm to the second algorithm.

Step S1: monitoring the ACK and NACK messages received from the mobile terminal;

Step S2: determining whether the number of consecutive NACKs received at any given time exceeds the first threshold. If so, go to step S3; if not, go to step S4.

Step S3: determining the adjustment value and decreasing the CQI value according to this value.

Step S4: Determine whether the number of consecutive ACKs received exceeds a second threshold. If so, go to step S5; if not, go to step S6.

Step S5: determining the adjustment value and increasing the CQI value accordingly.

Step S6: Does the first measurement interval end? If it is finished, go to step S7; if not, return to step S1.

Step S7: monitor the received NACK message during the second measurement interval.

Step S8: Determine the NACK ratio in the second measurement interval.

Step S9: Is the NACK rate greater than the first rate threshold? If larger, go to step 10; if not, go to step S11.

Step S10: determining the adjustment value, and decreasing the CQI value according to this value. The procedure is over.

Step S11: Is the NACK rate smaller than the second rate threshold? If it is smaller, go to step 12; otherwise, the procedure ends.

Step S12: determining the adjustment value, and increasing the CQI value according to this value. The procedure is over.

After step S10, step S11 and step S12, the procedure starts again at step S7 to calculate another adjustment value if desired.

In each of the embodiments described above, three specific cases occur, which can be handled as follows, for example:

If the CQI reported by the mobile terminal is zero, the adjusted CQI is also set to zero.

If the CQI adjustment algorithm produces more than 30 results, then the adjusted CQI is set to 30.

If the received CQI non-zero adjustment algorithm produces a value less than one, then the adjusted CQI is set to one.

The current adjustment value deltaCqi for the mobile terminal can only be maintained while communicating with the network. If idle, the adjusted value is lost, then the mobile terminal hopes to communicate with the network, and the CQI will have to be adjusted again. Since the error in determining the CQI can often be the deliberate error of the mobile terminal itself, it may be advantageous if possible to maintain the adjusted CQI value or if possible.

Although the present invention has been described above with regard to the WCDMA system, those skilled in the art will recognize that channel quality estimation may be implemented in any cellular communication network reported by the mobile terminal to the network.

Claims (20)

As a node used by the cellular network 4 to control data transmission from the wireless base station 3 of the cellular network to the mobile terminal 1, the node 5 is a sensed channel quality value reported by the mobile terminal. And a memory 7 for storing an acknowledgment and negative response message received from the mobile terminal in response to a data block transmitted from the wireless base station to the mobile terminal, and the detection based on the acknowledgment and negative response message. Calculation means 9 for calculating an adjustment value for the established channel quality value, wherein the memory 7 is also arranged to store the adjusted value for the sensed channel quality value from a wireless base station of the cellular network. A node used in a cellular network to control data transmission to a mobile terminal, The calculating means 9 is arranged to calculate the adjustment value for the sensed channel quality value taking into account two or more responses relating to two or more blocks and to use the adjustment value to calculate the adjusted value. A node used in a cellular network for controlling data transmission from a wireless base station to a mobile terminal in a cellular network. The method of claim 1, If the two or more responses comprise two or more consecutive negative responses, the calculation means 9 is arranged to reduce the sensed channel quality value by a predetermined amount. Node used in a cellular network to control the transmission of data to a terminal. The method according to claim 1 or 2, If said two or more responses comprise two or more consecutive acknowledgments, said calculating means 9 is arranged to increase said sensed channel quality value by a predetermined amount from the radio base station of the cellular network. Node used in a cellular network to control data transmission to a mobile terminal. The method of claim 2, And wherein said predetermined number of consecutive negative responses is set to two. A node for use in a cellular network to control data transmission from a wireless base station to a mobile terminal in a cellular network. The method of claim 3, wherein And said predetermined number of consecutive acknowledgments is set to 10. A node for use in a cellular network to control data transmission from a wireless base station to a mobile terminal in a cellular network. The method of claim 1, The memory 7 is arranged to collect data from an amount of data blocks sufficient to determine the percentage of acknowledgments and negative acknowledgments, and the calculating means 9 calculates a block error rate in which the number of the negative acknowledgments is higher than a predetermined threshold rate. Decrease the sensed channel quality value, and if the number of acknowledgments indicates a block error lower than a predetermined threshold rate, decrease the sensed channel quality value to determine an acknowledgment and / or negative response. And a node for use in the cellular network for controlling data transmission from the wireless base station in the cellular network to the mobile terminal. The method of claim 5, And said predetermined threshold rate corresponds to a block error rate of 10%. A node used in a cellular network to control data transmission from a wireless base station to a mobile terminal in a cellular network. The method of claim 1, The memory 7 comprises a first value defining a first measurement interval, and the calculation means 9 If the two or more responses include two or more consecutive negative responses during the first measurement interval, reduce the sensed channel quality value by a predetermined amount, and wherein the two or more responses identify two or more consecutive confirmations. If including the response, increase the channel quality value detected after the first measurement interval by a predetermined amount; After the first measurement period, if the data is collected from a sufficient number of data blocks to determine the percentage of acknowledgments and negative acknowledgments, and the number of negative acknowledgments indicates a block error rate higher than a predetermined threshold rate, then the detected channel quality value Control the data transmission from the wireless base station to the mobile terminal of the cellular network, characterized in that it is arranged to reduce the error rate and increase the detected channel quality value if the block error rate is indicated if the number of acknowledgments is lower than the predetermined threshold rate. Node used by the cellular network for the purpose. A method used in a network to adjust a sensed channel quality value reported by a mobile terminal to a wireless base station transmitting a data block to a mobile terminal, wherein the mobile terminal is assigned to each block of data transmitted to the mobile terminal. In response to an acknowledgment message indicating that the block was received correctly or a negative response message indicating that the block was received incorrectly, the detection reported by the mobile terminal to a wireless base station transmitting a data block to the mobile terminal. In the method used in the network to adjust the channel quality value, Monitoring two or more responses corresponding to two or more blocks of data transmitted to the mobile terminal, Determining based on the two or more responses whether or not the sensed channel quality value should be adjusted; And Adjusting the sensed channel quality value to a wireless base station transmitting a data block to the mobile terminal according to the determined, in order to adjust the sensed channel quality value reported by the mobile terminal. How to be. The method of claim 9, The monitoring step includes monitoring two or more responses corresponding to two or more consecutive blocks of data transmitted to the mobile terminal to the wireless base station transmitting the data block to the mobile terminal. The method used in the network to adjust the sensed channel quality value reported by. The method according to claim 9 or 10, If the at least two responses comprise two or more consecutive negative responses, reducing the sensed channel quality value by a predetermined amount by the mobile terminal to a wireless base station transmitting data blocks to the mobile terminal. The method used in the network to adjust the perceived channel quality value reported. The method according to claim 9 or 11, If the two or more responses include two or more consecutive acknowledgments, increase the sensed channel quality value by a predetermined amount by the mobile terminal to a wireless base station transmitting a data block to the mobile terminal. The method used in the network to adjust the perceived channel quality value reported. The method of claim 11, Used by the network to adjust the sensed channel quality value reported by the mobile terminal to a wireless base station transmitting a data block to the mobile terminal, characterized in that the predetermined number of consecutive negative responses is two. Way. The method of claim 12, And said predetermined number of negative responses is 10. A method used in a network to adjust a sensed channel quality value reported by said mobile terminal to a wireless base station transmitting a block of data to said mobile terminal. The method of claim 9, Collecting data from a predetermined number of data blocks, wherein the predetermined number of blocks is sufficient to determine the percentage of acknowledgments and negative acknowledgments and wherein the number of negative acknowledgments is greater than a predetermined threshold rate. Reduce the sensed channel quality value and increase the predetermined channel quality value if the number of acknowledgments indicates a block error rate lower than the predetermined threshold rate. A method used in a network to adjust a sensed channel quality value reported by a mobile terminal to a wireless base station transmitting. The method of claim 15, A method used in the network to adjust the sensed channel quality value reported by the mobile terminal to a wireless base station transmitting a data block to the mobile terminal, wherein the predetermined threshold rate corresponds to 10% of the block error rate. . The method of claim 9, At least a first measurement interval is defined, If the two or more responses include two or more consecutive negative responses during the first measurement interval, reduce the sensed channel quality value by a predetermined amount, and the two or more responses comprise two or more consecutive acknowledgments. If included, increase the channel quality value detected after the first measurement interval by a predetermined amount, After the first measurement period data is collected from a predetermined number of data blocks, the predetermined number of blocks being sufficient to determine the percentage of acknowledgments and negative responses, the number of negative responses being higher than a predetermined threshold rate. If the block error rate is indicated, the detected channel quality value is reduced; if the number of acknowledgments is lower than the predetermined threshold rate, the detected channel quality value is increased if the block error rate is shown; Used in the network to adjust the sensed channel quality value reported by the mobile terminal to a wireless base station. A computer program product comprising a program, when operating at a node associated with a mobile base station in a mobile telecommunications network, which causes the node to perform the method according to any of claims 8-14. A base station for use in a cellular telecommunication system, A base station for use in a cellular telecommunication system, comprising a node according to any one of claims 1 to 8. A cellular telecommunication system comprising at least a first base station 3 arranged to communicate with at least one mobile terminal 1, At least one mobile terminal, characterized in that the system comprises a node according to any one of claims 1 to 8 for controlling data transmission from the mobile base station 3 to at least one mobile terminal 1. At least a first base station arranged to be in communication with the system.

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