WO2014047862A1

WO2014047862A1 - Methods, devices and computer program products for scheduling request transmission

Info

Publication number: WO2014047862A1
Application number: PCT/CN2012/082269
Authority: WO
Inventors: Chunyan Gao; Jing HAN; Wei Bai; Haiming Wang; Samuli Turtinen
Original assignee: Broadcom Corp
Current assignee: Broadcom Corp
Priority date: 2012-09-28
Filing date: 2012-09-28
Publication date: 2014-04-03
Anticipated expiration: 2015-03-28

Description

METHODS, DEVICES AND COMPUTER PROGRAM PRODUCTS FOR SCHEDULING REQUEST TRANSMISSION

Field of the invention

The present invention relates to methods, devices and computer program products for scheduling request transmission.

Background

The following meanings for the abbreviations used in this specification apply

CQI channel quality indicator

DL downlink

DRX discontinuous reception

E-UTRA evolved universal terrestrial radio access

E-UTRAN evolved universal terrestrial radio access network

eIMB evolved Node B

LA location area

IM instant messaging

LTE long term evolution

LTE-A long term evolution advanced

MAC media access control

MCS modulation and coding scheme

MTC machine type communication

NW network

PC power control

PDCCH physical downlink control channel

PDSCH physical downlink shared channel

PLMN public land mobile network PRACH physical random access channel

PRB physical resource block

PUCCH physical uplink control channel

PUSCH physical uplink shared channel

RAN radio access network

RNTI radio network temporary identifier

RRC radio resource control

SI study item

SR scheduling request

TA tracking area

TPC transmitter power control

UE user equipment

UL uplink

3GPP 3^rd generation partnership project

Embodiments of the invention relate to LTE-Advanced system which will be part of 3GPP LTE Rel-11. More specifically, it is focused on small data transmission in MTC and enhanced diverse data transmission topics in the LTE-Advanced system.

Mobile data transmission and data services are constantly making progress. Under one aspect of such progress, more efficient management of system resources (e.g. UL control channel resources) for connected mode UEs that are temporarily inactive is being investigated, whereby potentially larger user populations in connected mode is facilitated.

One important use case of the UEs that are temporarily inactive is MTC UEs, which are UEs equipped for MTC, and which communicate through a PLMN with MTC server(s) and/or other MTC device(s). In 3GPP, MTC is studied in 3GPP RAN. Currently, on the ongoing SI with respect to MTC deals with achieving RAN improvements for MTC, focusing on avoiding RAN overload in order to protect normal legacy UEs which conform to superseded versions of the RAN interface specification, and to improve RAN efficiency when a large number of MTC devices are accessed.

It is known that small data transmission is one of defined features of MTC. Small data transmission is also one of prioritized features/requirements. Besides the small size, another feature of the traffic is that it is intermitted, i.e. there can be a large time interval between two transmissions. It has been shown that in such a case, reserved UL control resource, e.g. SR resource and CQI resource for such UEs can be a waste.

It is further known that the SR resource is currently configured by assigning a period and one subframe offset. This is determined by the RRC parameter sr-Configlndex. The period can be set to 1ms, 2ms, 5ms, 10ms, 20ms, 40ms or 80ms.

For UEs with some intermitted traffic with large arrival interval, like background traffic and IM traffic, the SR period can be set large. However, even with a large SR period, such as 80ms, the usage rate of SR is still low for some traffic type.

In order to save UE power, especially for UEs with intermitted traffic, DRX can be configured. In such a case, the inactive state helps to avoid unnecessary PDCCH detection. There had been discussion on some UE- assisted DRX configuration in 3GPP so as to optimize the DRX configuration considering the UE traffic estimation. In such a case, traffic is more possible to happen in DRX OFF duration. Basically, it can be expected that when DL traffic occurs, there is likely UL traffic to happen as well. In such a case, there is no more chance that SR transmission is available during DL data/control compared to the DRX ON duration. This results in some unnecessary SR resource reservation (for DRX ON duration), and a longer delay in UL transmission (for DRX OFF duration). Moreover, it should be noted that during DRX ON, the UE does not monitor C-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI and Semi-Persistent Scheduling C-RNTI (if configured). But according to active time definition, once the UE sends a SR, it always has to monitor ail possible downlink control channels after the SR is sent. This reduces the DRX ON duration and increases UE power consumption.

It has been proposed to increase the range of sr-Configlndex by adding more integers for sr-Configlndex in SR configuration. The added new integers can be of the order 2ⁿ. The problem is that this will result in a different SR index table for new and legacy UEs. Also, it is hard to decide/evaluate which integer is suitable to be added. Moreover, as already dealt with above, such SR configuration with a single period does not consider the relationship between DL and UL traffic, which can thus result in unnecessary reservation.

Further, another way for SR period extension has been proposed by introducing some restriction for SR transmission. However, the problems outlined above are not solved.

These problems motivate the enhancement to current SR configuration.

Summary

The present invention addresses such situation and proposes in exemplary embodiments, new solutions for enhancement of SR transmissions to ^"improve the resource efficiency. Various aspects of examples of the invention are set out in the claims.

According to an aspect of the present invention, there is provided e.g. in relation to a UE, an apparatus as defined in claim 1, and

a method as defined in claim 14.

According to a further aspect of the present invention, there is provided e.g. in relation to an elMB,

an apparatus as defined in claim 27, and

a method as defined in claim 38.

Advantageous developments of each such aspect are set out in respective dependent claims.

According to a further aspect of the present invention, as defined in claims 49 and 50, respectively, there are provided computer program products comprising computer-executable components which, when the program is run on a computer, are configured to perform the above method aspects according to the independent as well as respective dependent claims.

That is, such computer program products also encompass computer readable storage media comprising a set of computer-executable instructions which, when the program is run on a device (or on a processor or processing unit thereof which may be part of a controller or control unit or control module), such as a network transceiver device elMB and its processor, cause the device to perform the method aspects. In particular, the above computer program product/products may be embodied as a computer-readable storage medium.

Accordingly, under at least some example aspects of the present invention, improvements are achieved in that:

- more flexibility for SR configuration is provided,

- the resource efficiency of SR transmission is improved,

- a better cooperation with DRX configuration is attained, thereby resulting in greater UE power saving, - the implementation and specification of SR configuration and SR transmission is simplified,

- the SR configuration method is optimized, and

- SR configuration and DRX configuration are not independent from each other.

Brief description of drawings

For a more complete understanding of example embodiments of the present invention, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

Fig. 1 schematically illustrates a UE according to at least one exemplary embodiment.

Figs. 2 to 4 show flow charts for describing basic operations of the UE according to at least one exemplary embodiment. Fig. 5 schematically illustrates an eNB according to at least one exemplary embodiment.

Figs. 6 to 8 show flow charts for describing basic operations of the eNB according to at least one exemplary embodiment.

Fig. 9 shows, as a first example, the relationship between a DRX pattern and SR transmission of a flexible SR configuration according to at least one exemplary embodiment.

Fig. 10 shows, as a second example, the relationship between a DRX pattern and a flexible SR transmission, as well as the impact on DRX according to at least one exemplary embodiment.

Fig. 11 shows the relationship between a DRX pattern and SR transmission of a fixed SR configuration, and the impact on DRX according to the state of the art.

Fig. 12a shows a flow chart for activating the SR period P_SR_acove in dependence of the active state of the UE and the "OnDurationTimer" according to at least one exemplary embodiment.

Fig. 12b shows a flow chart for deactivating the SR period P_SR_active in dependence of the "OnDurationTimer" according to at least one exemplary embodiment.

Fig. 13a shows a flow chart for activating the SR period PsR_active in dependence of the active state of the UE and the "OnDurationTimer" according to at least one exemplary embodiment. Fig. 13b shows a flow chart for deactivating the SR period P_S _acuve in dependence of the "OnDurationTimer" according to at least one exemplary embodiment.

Description of exemplary embodiments

Exemplary aspects of the invention will be described herein below.

It is to be noted that the following exemplary description refers to an environment of the LTE system (long term evolution) and/or local area networks thereof. However, it is to be understood that this serves for explanatory purposes only. Other systems differing from the LTE system can be adopted. In such other systems, signaling states and/or parameters may be assigned different names.

Next, an example of at least one embodiment is described by referring to Figs, 1 to 10. Generally, Figs. 1 to 4 pertain to a terminal aspect, while Figs. 5 to 8 pertain to a NW device aspect.

Fig. 1 illustrates a simplified block diagram of a terminal such as a user equipment (UE) 1 according to at least one embodiment of the present invention. The UE may comprise the apparatus according to at least this embodiment, so that the apparatus may be installed in, inserted or plugged into an UE, for example. Moreover, also the UE is only an example and may be replaced by another suitable terminal.

UEs are often referred to as, for example, mobile devices, mobile stations, mobile units, subscriber stations, wireless terminals, or the like. The UE 1 may be implemented as, for example, a wireless handheld device, a wireless plug-in accessory, or the like. In some cases, the user equipment may include one or more of the following : at least one processor, at least one computer-readable storage medium (e. g . , memory, storage, and the like), one or more radio access mechanisms, and a user interface. For exa mple, the U E 1 may take the form of a wireless telephone, a mobile phone, a computer with a wireless connection to a network, or the like.

The UE 1, i .e. the apparatus la, according to this embodiment comprises a processor 11 and a memory 12. The memory comprises a computer program, wherein the memory 12 and the computer program are configured to, with the processor, cause the apparatus to perform several operations as described below. Optionally, the UE 1 and/or the apparatus la may also comprise an interface 13 for providing connections to network elements. Moreover, the processor 11, the memory 12 and the interface 13 may be inter-connected by a suitable connection 14, e.g . , a bus or the like. Moreover, it is noted that the apparatus may comprise more than one processor, more than one memory and/or more than one interface, if this is suitable for a particular structure.

Fig . 2 shows a flow chart for describing at least a basic operation according to the present embodiment, which may be performed by the U E 1/apparatus la shown in Fig . 1. In particular, in a stage S21, a receiver module is caused by a controller of the UE 1/apparatus la to assume one of at least two reception modes. The receiver module can be included in the U E 1/apparatus la . Alternatively, the receiver module does not necessarily have to be included in the U E 1/appa ratus la . Rather, the receiver module can be connected to the UE 1. For instance, the receiver module and insofar the U E 1 to which it is associated can be in a first reception mode in which the receiver module is inactive (DRX on), i .e. the receiver module is switched off to save energy so that the U E 1 does not have to decode the PDCCH or receive PDSCH transmissions in certain subfra mes. Otherwise, the UE 1 can be in a second reception mode in which the receiver module is active (DRX off), i.e. the receiver module is switched on. In a stage S22, a transmitter module is caused by the controller of the UE 1/apparatus la to send scheduling requests to the network device such as e.g. an eNB. The transmitter module can be included in the UE 1/apparatus la. Alternatively, the transmitted module does not necessarily have to be included in the UE 1/apparatus la. Rather, the transmitter module can be connected to the UE 1/apparatus la. Further, a period between two consecutive scheduling requests differs depending on the reception mode of the receiver module.

Fig. 3 shows a flow chart for describing at least a further basic operation according to the present embodiment, which may be performed by the UE 1/apparatus la shown in Fig. 1. In Fig. 3, it is at least outlined when a scheduling request is sent. In particular, in a stage S31, an occurrence of data to be transmitted to a network device such as e.g. an eNB is detected by the controller of the UE 1/apparatus la. In a stage S32, the transmitter module is caused by the controller of the UE 1/apparatus la to send a scheduling request in response to the detection of the occurrence of data to be transmitted to a network device. The scheduling request is sent e.g. upon a start of the period between two consecutive scheduling requests or upon expiry of the period. This depends on whether the detection of the occurrence of data to be transmitted to a network device is made prior to the period between two consecutive scheduling requests or in the period between two consecutive scheduling requests. In case the detection is made prior to the period, the scheduling request is send upon the start of the period, whereas in case the detection is made in the period, the scheduling request is send upon expiry of the period.

According to at least this embodiment, the period (first period) between two consecutive scheduling requests in the first reception mode, i.e. when the receiver module is inactive, is longer than the period (second period) between two consecutive scheduling requests in the second reception mode, i.e. when the receiver module is active.

According to at least this example embodiment, at least one of the first period and the second period are configured explicitly by a network device such as e.g. an eNB. Optionally, the first period and the second period are configured explicitly by the network device. Alternatively, the first or second period which is not explicitly configured can be derived by the controller of the UE 1/apparatus la based on the period which is explicitly configured by e.g. comparing the length of the period with a predetermined total length to be used for both the first and second period, and subtracting the length of the period from the predetermined total length.

Moreover, optionally according to a further modification of the above outlined example embodiment, the period between two consecutive scheduling requests may further differ depending on a traffic type received and/or transmitted, e.g. whether it is real time traffic or non real time traffic.

Fig. 4 shows a flow chart for describing at least a further basic operation according to at least this example embodiment, which may be performed by the UE 1/apparatus la shown in Fig. 1. In a stage S41, the reception mode of the receiver module is monitored by the controller of the UE 1/apparatus la. In a stage S42 it is switched between the first period and second period by the controller of the UEl/apparatus la depending on the reception mode in response to monitoring the reception mode of the receiver module.

Fig. 5 shows an eNB 5 as an example of a network element which e.g. comprises an apparatus 5a which causes the SR configuration. The eNB 5/apparatus 5a according to this example embodiment comprises a processor 51 and a memory 52. The memory comprises a computer program, wherein the memory 52 and the computer program are configured to, with the processor, cause the apparatus 5a to perform several operations as described below. Optionally, the eNB 5 and/or the apparatus 5a may also comprise an interface 53 for providing connections to terminals. Moreover, the processor 51, the memory 52 and the interface 53 may be inter-connected by a suitable connection 54, e.g., a bus or the like. Moreover, it is noted that the apparatus may comprise more than one processor, more than one memory and/or more than one interface, if this is suitable for a particular structure.

Fig. 6 shows a flow chart for describing at least a basic operation according to this example embodiment, which may be performed by the eNB 5/appartus 5a shown in Fig. 5. Specifically, in a stage S61, at least one period between two consecutive scheduling requests is caused by a controller of the eNB 5/apparatus 5a to be configured for at least two reception modes of a terminal, respectively, such as e.g. a UE. The at least one period differs depending on the reception mode of the terminal such as e.g. a UE. That is, the controller of the eNB 5/apparatus 5a causes the at least one period to be configured depending on the reception mode of the terminal. This is achieved in that the controller of the eNB 5/apparatus 5a performs RC. By doing so, the controller of the eNB 5/apparatus 5a causes RRC signaling by means of which the E-UTRAN controls the behavior of the UE.

Fig. 7 shows a flow chart for further describing at least a basic operation according to this example embodiment, which may be performed by the eNB 5/apparatus 5a shown in Fig. 5. Specifically, in order to cause the first period to be configured for the first reception mode, a first scheduling request configuration parameter is defined by the controller of the eNB 5/apparatus 5a in a stage S71. According to this definition in the stage S71, the first period is determined by the controller of the eNB 5/apparatus 5a. Furthermore, in order to cause the second period to be configured for the second reception mode, a second scheduling request configuration parameter is defined by the controller of the eNB 5/apparatus 5a in a stage S72. According to this definition in the stage S72, the second period is determined by the controller of the eNB 5/apparatus 5a.

Optionally, the controller of the eNB 5/apparatus 5a configures explicitly at least one of the first period and the second period. Optionally, the controller of the eNB 5/apparatus 5a configures explicitly the first period and the second period. Alternatively, the controller of the eNB 5/apparatus 5a causes to derive the first or second period which is not explicitly configured based on the period which is explicitly configured in that e.g. the controller of the eNB 5/apparatus 5a causes the length of the period to be compared with a predetermined total length to be used for both the first and second period, and the length of the period to be subtracted from the predetermined total length.

Fig. 8 shows a flow chart for describing at least a further basic operation according to the present example embodiment, which may be performed by the eNB 5/apparatus 5a shown in Fig. 5. In a stage S81, data are transmitted by the controller of the eNB 5/apparatus 5a to the terminal such as e.g. a UE in the second reception mode of the terminal prior to the start of the second period. Upon this transmission, in a stage S82, the second period is caused by the controller of the eNB 5/apparatus 5a to be activated.

The foregoing basic operations with respect to the UE and the eNB are described in the following in more detail according to two specific examples of the present example embodiment. These examples are shown in Figs. 9 and 10.

Fig. 9 shows, as a first example, the relationship between a DRX pattern and SR transmission of a flexible SR configuration according to at least one exemplary embodiment. As already outlined in the foregoing, the receiver module is inactive in the first reception mode, whereas it is active in the second reception mode. According to Fig. 9, UL data arrival happens in the active state of the UE (DRX off) (i.e. second reception mode) rather than in the inactive state of the UE (DRX on) (i.e. first reception mode). In this regard, UL data arrival is to be understood as the arrival of data at the UE which are to be transmitted from the UE to the network device such as e.g. an eNB. According to this example, the SR period (i.e. the period between two consecutive scheduling requests) for the active state of the UE and the SR period for the inactive state of the UE are separately configured. That is, the SR period is configured depending on the active state of the UE and the inactive state of the UE, i.e. depending on the reception mode of the UE. In Fig. 9, the SR period for the active state of the UE and the SR period for the inactive state of the UE is denoted by PsR_aetive and PsRjnactive, respectively. Both periods are configured such that PsRjnactive is longer than Ps __acti e, i.e. both periods differ from each other, as can be seen from Fig. 9.

As already outlined in the foregoing, at least one of the SR periods _S _active and sRjnactive is explicitly configured. Optionally, both of these periods are explicitly configured. Alternatively, the other SR period which is not explicitly configured is derived based on the period which is explicitly configured. Optionally, the eNB activates the SR period PsR_„active by causing DL data arrival at the UE, e.g. when one DL grant is received by the UE in the second reception mode. For instance, when the UE receives DL data in the active state of the UE, then the UE will assume that the configured SR period P_SR_active is available.

Optionally, as already outlined in the foregoing, the SR period

implicitly activated in the active state of the UE, and the SR period _SR_active is implicitly deactivated in the inactive state of the UE. Further, the SR period PsRjnactive is implicitly activated in the inactive state of the UE, and the SR period Psajnactive is implicitly deactivated in the active state of the UE.

Optionally, the eNB causes configuration of the SR periods based on the UE traffic type, e.g. whether the UE supports real time traffic or non real time traffic.

As can be seen from Fig. 9, UL data arrival, i.e. arrival of data at the UE for UL transmission, triggers the transmission of a SR. With respect to the first active state of the UE, the first data arrival happens prior to the start of the first SR period. In this case, transmission of the SR is performed upon the start of the first SR period. In case UL data arrival happens in any of the SR periods - either during the active state of the UE or during the inactive state of the UE - transmission of the SR is performed upon expiry of the particular SR period. Herein, the UL transmission delay is short. Since no UL data happens during the inactive state of the UE according to the example shown in Fig. 9, the SR reserved in the inactive state is wasted, but the waste is reduced due to the large period PsRjnacuve-

The proposal according to Fig. 9 allows a very flexible SR period configuration which has the effect of SR resource saving. This effect is primarily achieved by separately configuring the SR periods for the active state and inactive state of the UE, i.e. depending on the reception mode of the UE, such that the SR period for the inactive state of the UE is longer than for the active state of the UE and, hence, differ from each other. Thereby, resource efficiency concerning transmission of the SR is further achieved.

Fig. 10 shows, as a second example, the relationship between a DRX pattern and a flexible SR transmission, as well as the impact on DRX according to at least one exemplary embodiment. As already outlined in the foregoing, the receiver module is inactive in the first reception mode, whereas it is active in the second reception mode. As performed for the first example, the eNB separately configures the SR period for the active state of the UE and the inactive state of the UE in the second example as well. That is, the eNB configures the SR period depending on the active state of the UE and the inactive state of the UE, i.e. depending on a reception mode of the UE. Also in Fig. 10, the SR period for the active state of the UE and the inactive state of the UE is denoted by P_S _active and PsRjnactive, respectively.

The main difference between the examples of the at least one exemplary embodiment according to Figs. 9 and 10 is that according to Fig. 9 no UL data arrival happens in the inactive state of the UE, whereas according to Fig. 10, UL data arrival can be observed during both the active and inactive state of the UE. Apart from that, the same principles and the same functionality outlined in connection to the first example shown in Fig. 9 also apply on the second example shown in Fig. 10.

According to the second example, UL data arrival triggers the transmission of a scheduling request in the same way as for the first example of the first embodiment. In case UL data arrival happens in PSR inactive, the UE enters the active state for UL grant detection upon expiry of Ps jnacti e- That is, the SR transmission in the inactive state of the UE causes the active state of the UE to be extended, as indicated by the grey area in Fig. 10.

The second example showing a flexible SR transmission is compared with a fixed SR configuration according to the state of the art. In this regard, Fig. 11 shows the relationship between a DRX pattern and SR transmission of a fixed SR configuration, and the impact on DRX according to the state of the art. Specifically, Fig. 11 exemplifies with a single SR period configuration. In this case, the SR configuration and the DRX configuration are independent from each other. This is due to the fact that the SR configuration is fixed according to Fig. 11. That is, as to the SR configuration, no difference is made whether the UE is in its active or in its inactive state. As can be seen from Fig. 11, the SR period between two consecutive scheduling requests nearly has the same length - independent from the DRX configuration, i.e. whether the UE is in its active or in its inactive state. Hence, due to such a fixed SR configuration, UL data arrival triggers more SR transmissions as compared to UL data arrival in the second example shown in Fig. 10. Hence, as for UL data arrival in the inactive state of the UE, UL data arrival does not only cause the UE to enter the active state for UL grant detection upon expiry of the SR period in which UL data arrival has happened, but may also elongate the active state of the UE to a higher extent as compared to the second example shown in Fig. 10, which gets also obvious by comparing the grey areas of Figs. 10 and 11. Hence, the fixed SR configuration according to the state of the art shown in Fig. 11 may lead to an increased power consumption of the UE.

In contrast thereto, according to the second example of the at least one exemplary embodiment, the SR transmission is reduced due to sRjnactive being longer than P_SR_a_tive- Consequently, the extension of the active state of the UE is reduced accordingly. In view of this, the flexible SR transmission shown in Fig. 10 has the effect of power saving.

Moreover, according to the present example embodiment, the flexible SR configuration and the flexible SR transmission according to Figs. 9 and 10 are implemented so that the SR resource with SR period P_SR__active is only available during the active state of the UE and before the so-called "OnDurationTimer" expires, wherein the so-called "OnDurationTimer" specifies the number of consecutive PDCCH-subframe(s) at the beginning of a DRX cycle.

Fig. 12a shows a flow chart for activating the SR period P_SR active in dependence of the active state of the UE and the "OnDurationTimer", whereas Fig. 12b shows a flow chart for deactivating the SR period P_SR active in dependence of the "OnDurationTimer".

With respect to Fig. 12a, in a stage S121, the active state of the UE is set to the ON state. That is, DRX is set off. Upon setting the active state of the UE to the ON state, in a stage S122, the "OnDurationTimer" starts counting the number of consecutive PDCCH-subframe(s). Upon starting counting the number of consecutive PDCCH-subframe(s), in a stage S123, the SR period PsR_active is activated.

With respect to Fig. 12b, in a stage S124, it is checked whether the "OnDurationTimer" has expired. In case it has expired ("YES" in a stage S124), it is proceeded to a stage S125, in which the SR period P_SR_activ_e is deactivated. Upon deactivation of the SR period sR_act e_/ in a stage S126, the inactive state of the UE is set to the ON state. That is, DRX is set on. In case it has not expired ("NO" in a stage S124), in a stage S127, the active state of the UE is remained in the ON state.

Accordingly, the eNB can easily know beforehand whether the SR resource with the SR period PsR_active can be used by the UE or not. Further, a reuse of the PUCCH resource is simplified for other UEs.

Next, a another at least one exemplary embodiment is described. Basically, the present example embodiment mainly corresponds to the at least one exemplary embodiment as outlined in the foregoing so that the principles and functionality according to the at least one exemplary embodiment also apply on the present example embodiment.

The only difference between these example embodiment consists in the implementation of the flexible S configuration and the flexible SR. transmission according to Figs. 9 and 10. Specifically, according to the present example embodiment, the SR resource with period P_SR_active is available during all active states of the UE so that the SR resource with the SR period P_SR__active is also available in the grey area shown in Fig. 10, i.e. the area by means of which the active state of the UE is extended in response to UL data arrival in the inactive state of the UE.

The consequence of the functionality of the present example embodiment is that the availability of the SR resource with the SR period P_SR__active can only be known by the el\IB several ms before the SR period. This has the effect that the reuse of the SR resource by other UEs is restricted. However, a greater possibility for SR transmission is provided since the SR resource with the SR period Ps ^active is also available in the grey area shown in Fig. 10.

Next, another at least one exemplary embodiment is described by referring to Figs. 13a and 13b. Basically, the present example embodiment mainly corresponds to the at least one exemplary embodiment as outlined in the foregoing so that the principles and functionality according to the at least one exemplary embodiment also apply on the present example embodiment.

The only difference between these example embodiments consists in the implementation of the flexible SR configuration and the flexible SR transmission according to Figs. 9 and 10. Specifically, according to the present example embodiment, the SR resource period P_S _active is implicitly activated n subframes after the socalled "OnDurationTimer" has started running, and is deactivated when the OnDurationTimer expires. With respect to Fig. 13a, in a stage S131, the active state of the UE is set to the ON state. That is, DRX is set off. Upon setting the active state of the UE to the ON state, in a stage S132, the "OnDurationTimer" starts counting the number of consecutive PDCCH-subframe(s). At the same time, in a stage S132, an index i is initialized so that i=0. In a stage S133, it is determined whether i equals n. In case i equals n ("YES" in a stage S133), it is proceeded to a stage S135 in which the SR period P_SR_active is activated. In case i is not equal to n ("NO" in a stage S133), it is proceeded to a stage S134 in which the index i is incremented by 1. Then, it is returned to a stage S133.

With respect to Fig. 13b, in a stage S136, it is checked whether the "OnDurationTimer" has expired. In case it has expired ("YES" in a stage S136), it is proceeded to a stage S137, in which the SR period P_S _active is deactivated. Upon deactivation of the SR period PsR_acttve, in a stage S138, the inactive state of the UE is set to the ON state. That is, DRX is set on. In case it has not expired ("NO" in a stage S136), in a stage S139, the active state of the UE is remained in the ON state.

Accordingly, assuming that the SR mainly serves for sending DL related feedback, the SR is usually only required after DL transmission in the active state of the UE. In such a case, an offset of n subframes can further reduce unnecessary SR resource reservation.

The embodiments described above are implemented with respect to data transmission in MTC, but the invention is not limited to this, and can be applied to any case in which a SR has to be sent. Furthermore, the UEs are only examples for terminals. However, the present invention is not limited to these cases and can be applied to any terminal which requires to send scheduling requests.

Furthermore, also the eNBs described above are only examples for network control elements. The specific operations for performing the SR configuration and the like may also be carried out by another network control element, for example by a network element on a higher level in a network, in a central manner for the whole network or the like.

Embodiments of the present invention may be implemented in software, hardware, application logic or a combination of software, hardware and application logic. The software, application logic and/or hardware generally, but not exclusively, may reside on the devices' modem module. In an example embodiment, the application logic, software or an instruction set is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer or smart phone, or user equipment.

The present invention relates in particular but without limitation to mobile communications, for example to environments under LTE, WCDMA, WIMAX and WLAN and can advantageously be ^"implemented in user equipments or smart phones, or personal computers connectable to such networks. That is, it can be implemented as/in chipsets to connected devices, and/or modems or other modules thereof.

If desired, at least some of different functions discussed herein may be performed in a different order and/or concurrently with each other. Furthermore, if desired, one or more of the above-described functions may be optional or may be combined.

Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

Claims

WHAT IS CLAIMED IS:

1. An apparatus, comprising :

a controller arranged to :

cause a receiver module to assume one of at least two reception modes,

cause a transmitter module to send scheduling requests to a network device,

wherein a period between two consecutive scheduling requests differs depending on the reception mode of the receiver module.

2. An apparatus according to claim 1, wherein

in a first reception mode, the receiver module is inactive (DRX on), in a second reception mode, the receiver module is active (DRX off), and

a first period between two consecutive scheduling requests in the first reception mode is longer than a second period between two consecutive scheduling requests in the second reception mode.

3. An apparatus according to claim 2, wherein

at least one of the first period and the second period are configured explicitly.

4. An apparatus according to claim 3, wherein

the first period and the second period are configured explicitly.

5. An apparatus according to claim 3, wherein

the controller is further arranged to: derive the first or second period which is not explicitly configured based on the period which is explicitly configured.

6. An apparatus according to claim 1, wherein

the period between two consecutive scheduling requests further differs depending on a traffic type received and/or transmitted.

7. An apparatus according to claim 1, wherein

the controller is further arranged to :

detect an occurrence of data arriving from a network device, and responsive thereto, activate the period between two consecutive scheduling requests in the second reception mode.

8. An apparatus according to claim 2, wherein

the controller is further arranged to:

monitor a reception mode of the receiver module, and

responsive thereto, switch between the first period and second period between two consecutive scheduling requests depending on the reception mode.

9. An apparatus according to any one of claims 1 to 8, wherein the apparatus is arranged for use in a user equipment.

10. An apparatus according to claim 9, wherein the user equipment is a mobile device.

11. An apparatus according to any one of claims 9 and 10, wherein the user equipment is a mobile phone.

12. An apparatus according to any one of claims 1 to 11, wherein the apparatus is arranged for use in a long term evolution system.

13. An apparatus according to any one of claims 1 to 11, wherein the apparatus is arranged for use in a long term evolution advanced system.

14. A method, comprising :

causing a receiver module to assume one of at least two reception modes,

causing a transmitter module to send scheduling requests to a network device,

15. A method according to claim 14, wherein

16. A method according to claim 15, wherein

17. A method according to claim 16, wherein

the first period and the second period are configured explicitly.

18. A method according to claim 16, further comprising :

deriving the first or second period which is not explicitly configured based on the period which is explicitly configured.

19. A method according to claim 14, wherein

20. A method according to claim 14, further comprising :

detecting an occurrence of data arriving from a network device, and responsive thereto, activating the period between two consecutive scheduling requests in the second reception mode.

21. A method according to claim 15, further comprising :

monitoring a reception mode of the receiver module, and

responsive thereto, switching between the first period and second period between two consecutive scheduling requests depending on the reception mode.

22. A method according to any one of claims 14 to 21, wherein the method is used in a user equipment.

23. A method according to claim 22, wherein the user equipment is a mobile device.

24. A method according to any one of claims 22 and 23, wherein the user equipment is a mobile phone.

25. A method according to any one of claims 14 to 24, wherein the method is used in a long term evolution system.

26. A method according to any one of claims 14 to 24, wherein the method is used in a long term evolution advanced system.

27. An apparatus, comprising:

a controller arranged to :

cause to configure at least one period between two consecutive scheduling requests for at least two reception modes of another apparatus, respectively,

wherein the at least one period differs depending on the reception mode of the another apparatus.

28. An apparatus according to claim 27, wherein

the controller is further arranged to :

define a first scheduling request configuration parameter for determining a first period between two consecutive scheduling requests in a first reception mode of the another apparatus, and

define a second scheduling request configuration parameter for determining a second period between two consecutive scheduling requests in a second reception mode of the another apparatus.

29. An apparatus according to claim 28, wherein

in the first reception mode, a receiver module of the another apparatus is inactive (DRX on),

in the second reception mode, the receiver module of the another apparatus is active (DRX off), and

the first period is longer than the second period.

30. An apparatus according to any one of claims 28 and 29, wherein the controller is further arranged to :

configure explicitly at least one of the first period and the second period.

31. An apparatus according to claim 30, wherein

the controller is further arranged to:

configure explicitly the first period and the second period.

32. An apparatus according to claim 30, wherein

the controller is further arranged to:

cause to derive the first or second period which is not explicitly configured based on the period which is explicitly configured.

33. An apparatus according to claim 27, wherein

the at least one period between two consecutive scheduling requ further differs depending on a traffic type received and/or transmitted.

34. An apparatus according to any one of claims 28 and 29, wherein the controller is further arranged to:

transmit data to the another apparatus, and

responsive thereto, cause to activate the second period between two consecutive scheduling requests in the second reception mode.

35. An apparatus according to any one of claims 27 to 34, wherein the apparatus comprises an evolved NodeB or base station.

36. An apparatus according to any one of claims 27 to 35, wherein the apparatus is arranged for use in a long term evolution system.

37. An apparatus according to any one of claims 27 to 35, wherein the apparatus is arranged for use in a long term evolution advanced system.

38. A method, comprising:

causing to configure at least one period between two consecutive scheduling requests for at least two reception modes of another apparatus, respectively,

39. A method according to claim 38, further comprising:

defining a first scheduling request configuration parameter for determining a first period between two consecutive scheduling requests in a first reception mode of the another apparatus, and

defining a second scheduling request configuration parameter for determining a second period between two consecutive scheduling requests in a second reception mode of the another apparatus.

40. A method according to claim 39, wherein

the first period is longer than the second period.

41. A method according to any one of claims 39 and 40, further comprising : configuring explicitly at least one of the first period and the second period.

42. A method according to claim 41, further comprising:

configuring explicitly the first period and the second period.

43. A method according to claim 41, further comprising :

causing to derive the first or second period which is not explicitly configured based on the period which is explicitly configured.

44. A method according to cJaim 38, wherein

the at least one period between two consecutive scheduling requests further differs depending on a traffic type received and/or transmitted.

45. A method according to any one of claims 39 and 40, wherein

the controller is further arranged to :

transmit data to the another apparatus, and responsive thereto, cause to activate the second period between two consecutive scheduling requests in the second reception mode.

46. A method according to any one of claims 38 to 45, wherein the method is used for an evolved NodeB or base station.

47. A method according to any one of claims 38 to 46, wherein the method is used in a long term evolution system.

48. A method according to any one of claims 38 to 46, wherein the method is used in a long term evolution advanced system.

49. A computer program product comprising computer-executable components which, when the program is run on a computer, are configured to perform the method aspect as defined in claims 14 to 26.

50. A computer program product comprising computer-executable components which, when the program is run on a computer, are configured to perform the method aspect as defined in claims 38 to 48.