WO2017136995A1

WO2017136995A1 - Scheduling configuration methods for cellular communication systems

Info

Publication number: WO2017136995A1
Application number: PCT/CN2017/071663
Authority: WO
Inventors: Efstathios KATRANARAS; Olivier Marco; Ron Toledano; Guillaume Vivier
Original assignee: Jrd Communication Inc.
Priority date: 2016-02-11
Filing date: 2017-01-19
Publication date: 2017-08-17
Also published as: GB201602492D0; CN108605350A; GB2547243B; CN108605350B; GB2547243A

Abstract

In an LTE cellular communications system with Carrier Aggregation, the signalling overhead for a scheduling request configuration is reduced by omitting the dsr-TransMax in the Scheduling Request Configuration Information Elementin respect of an additional, configured Component Carrier. A further enhancement is to replace a per-Component Carrier Scheduling Request configuration index with a group configuration index which specifies an individual configuration index for each Component Carrier.

Description

Scheduling Configuration Methods for Cellular Communication Systems

Technical Field

Embodiments of the present invention generally relate to cellular communication systems and in particular to devices and methods for configuration of scheduling requests.

Background

Cellular communication systems， such as the third-generation (3G) of mobile telephone standards and technology are well known. Such 3G standards and technology have been developed by the Third Generation Partnership Project. The 3^rd generation of wireless communications has generally been developed to support macro-cell mobile phone communications. Such macro cells utilise high power base stations (NodeBs) to communicate with wireless communication devices within a relatively large geographical coverage area. Typically， wireless communication devices， or User Equipment (UEs) as they are often referred to， communicate with a Core Network (CN) of the 3G wireless communication system via a Radio Network Subsystem (RNS) . A wireless communication system typically comprises a plurality of radio network subsystems， each radio network subsystem comprising one or more cells to which UEs may attach， and thereby connect to the network. Each macro-cellular RNS further comprises a controller， in a form of a Radio Network Controller (RNC) ， operably coupled to the one or more NodeBs. Communication systems and networks have developed towards a broadband and mobile system. The 3rd Generation Partnership Project has developed a Long Term Evolution (LTE) solution， namely， an Evolved Universal Mobile Telecommunication System Territorial Radio Access Network， (E-UTRAN) ， for a mobile access network， and a System Architecture Evolution (SAE) solution， namely， an Evolved Packet Core (EPC) ， for a mobile core network. A macrocell in an LTE system is supported by a base station known as an eNodeB or eNB (evolved Node B) .

A further development， LTE-Advanced has introduced the concept of Carrier Aggregation (CA) in order to increase bandwidth. Each aggregated carrier is referred to as a Component Carrier (CC) . There is a serving cell for each component carrier， which may all be supported by a single eNB. A concept of primary cell (PCell) and secondary cell (SCell) has been introduced to support CA. The PCell， which is akin to a serving cell in the non-CA case， is typically used (amongst other functions) for PUCCH (Physical Uplink Channel) transmissions and RRC (Radio Resource Control) connection and re-establishment. An SCell may be added to the PCell or a set of serving cells through an RRC connection reconfiguration procedure.

Before a UE can transmit data to an eNB it must receive an Uplink (UL) grant message from the eNB. In LTE systems， UL grants are sent to UEs using dynamic scheduling (i.e. using the so-called Scheduling Request (SR) procedure) ， random access procedure or Semi-Persistent Scheduling (SPS) . An SR Configuration includes， amongst other things， an SR configuration index which includes an assigned periodicity and subframe offset value. The SR configuration index is used by the UE to determine the subframe where the scheduling request should be transmitted and thereby determine the next available opportunity for sending an SR. Dynamic Scheduling in LTE allows a UE to dynamically request (in a pre-configured way) UL resources from the radio access network with the dedicated SR (D-SR) mechanism letting an SR be conveyed on a dedicated resource on the PUCCH. In summary， dynamic scheduling comprises the following communication steps between the network and a UE： upon SR receipt at an eNB on the PUCCH， an UL grant is sent to the UE via DCI-0 (Downlink Control Information) on the PDCCH (Physical Downlink Control Channel) ； then the UE sends a BSR (Buffer Status Report， i.e. how much data is in the UE buffer to be sent out) at the first uplink packet； and then UL data is sent via PUSCH (Physical Uplink Shared Channel) ； then ACK/NACK message follows via PHICH (Physical Hybrid Activated Repeat Request Channel) .

The exact TTI (Transmission Time Interval) when an opportunity arises for a UE to perform SR transmission on a carrier depends on the SR periodicity and on the SR offset which has been configured via RRC signalling. RRC signalling is also used to control the maximum number of SR transmissions from a UE. The dsr-TransMax parameter in the SchedulingRequestConfig signal essentially indicates that uplink transmission may be problematic， e.g. PUCCH resources for SR may become invalid (due to poor signal quality or improper power settings， etc. ) or the UE may lose synchronisation on uplink timing and the SR sent on the PUCCH cannot be successfully received by the eNB.

In legacy (i.e. up to Release12 CA) ， only the PCell is configured with PUCCH； thus， UL grants via SR can be provided only through one carrier， that is， the PCell. It has been agreed that for Release 13 CA SR in the PUCCH on an SCell should be supported in order to relieve resource usage on the PCell. Further， up to two cells may be configured with PUCCH for a UE. Also， there should be only one SR procedure regardless of whether D-SR is configured on multiple cells. It has also been agreed that where SRs are configured on both activated PUCCH SCell and PCell， when the first UL packet is ready for transmission， the UE’s MAC entity instructs the physical channels to send the SR when the first opportunity arises and the UE MAC (Median Access Control) entity chooses one SR when SRs on PUCCH SCell and PCell are in the same TTI. Which one to choose is left to the UE’s implementation. For example， if multiple PUCCH resources for SR are valid for a TTI， due to multiple CCs available for SR transmission at the same time， it is left to UE implementation to decide which PUCCH resource to be used.

It would be advantageous to provide a means for reducing the amount of signalling required in UL dynamic scheduling in an LTE Advanced system where multiple carriers are used while maintaining compatibility with at least some of the above-mentioned proposals.

Summary

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter， nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

According to a first aspect of the present invention， there is provided a scheduling configuration method in a cellular communication system which supports Carrier Aggregation， the method including： transmitting a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system， transmitting a first Scheduling Request configuration wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a first Scheduling Request configuration index and a dsr-TransMax value； transmitting a secondary Component Carrier configuration for reception by the wireless communication device， transmitting a second Scheduling Request configuration， wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a second Scheduling Request configuration index but does not include a dsr-TransMax value.

Further Component Carrier configurations along with further Scheduling Request configurations may be transmitted wherein their associated Scheduling Request Information Elements may also omit a dsr-TransMax value.

According to a second aspect of the present invention， there is provided a network element which supports a primary Component Carrier and a secondary Component Carrier in a cellular communication system which supports Carrier Aggregation， the network element being arranged to transmit a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system， transmit a first Scheduling Request configuration for reception by the wireless communication device wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a first Scheduling Request configuration index and a dsr-TransMax value； transmit a secondary Component Carrier configuration for reception by the wireless communication device， transmit a second Scheduling Request configuration for reception by the wireless communication device， wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a second Scheduling Request configuration index but does not include a dsr-TransMax value.

The invention recognises the fact that a dsr-TransMax value may not need to be updated with every Component Carrier configuration (or reconfiguration) for a User Equipment. Transmitting information which is not required is wasteful of resources and so by omitting to send the dsr-TransMax value there is a saving on signalling load.

A decision as to whether to include a dsr-TransMax value in the Scheduling Request Information Element may be made by the network element， which may be an eNB. A factor that the network element (or eNB) may take into account when making this decision is latency for the wireless communication device (or UE) transmitting a packet. The dsr-TransMax value is one parameter which controls how much time the UE should wait before it abandons its attempt to obtain a PUSCH and begin a new attempt. There is only one SR procedure running at UE MAC entity， so only one value for dsr-Transmax is sent to the UE by the eNB at any CC (re) configuration. Where there is PUCCH resource on more than one CC， the UE will consider the latest updated dsr-TransMax value while sending SRs on any of these CCs. An eNB can set this value by e.g. taking into consideration the load on all CCs. So if a new PUCCH SCell is configured and the current dsr-TransMax value does not pose any limitation to e.g. this SCell’s PUCCH load， then there should be no need to update this value.

According to a third aspect of the invention， there is provided a scheduling configuration method in a cellular communication system which supports Carrier Aggregation， the method including： transmitting a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system， transmitting a first Scheduling Request configuration wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a Scheduling Request configuration index and a dsr-TransMax value， transmitting a secondary Component Carrier configuration for reception by the wireless communication device， transmitting a second Scheduling Request configuration， wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes Scheduling Request group configuration index which specifies an individual configuration index for each component carrier.

According to a fourth aspect of the invention there is provided a network element which supports a primary Component Carrier and a secondary Component Carrier in a cellular communication system which supports Carrier Aggregation， the network element being arranged to： transmit a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system， transmit a first Scheduling Request configuration wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a Scheduling Request configuration group index and a dsr-TransMax value， transmit a secondary Component Carrier configuration for reception by the wireless communication device， transmit a second Scheduling Request configuration wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a Scheduling Request group configuration index which specifies an individual configuration index for each component carrier.

The second Scheduling Request Information Element may or may not include a dsr-TransMax value.

The Scheduling Request group configuration index may comprise a bitmap which specifies an individual configuration index for each component carrier. In contrast with conventional techniques where a Scheduling Request configuration index is transmitted for each component carrier， the use of a bitmap instead means that fewer bits need to be included in the transmitted index， therefore providing a saving of resources.

According to a fifth aspect of the invention， there is provided a wireless communication device for use in a cellular communication system， wherein the wireless communication device is arranged to： receive primary and secondary Component Carrier configurations， receive first and second Scheduling Request configuration Information Elements from a network element of the cellular communication system in respect of the primary and secondary Component Carriers， and configure Scheduling Requests in accordance with the received first and second Scheduling Request configuration Information Elements， wherein the second Scheduling Request configuration Information Element includes a Scheduling Request group configuration index specifying an individual configuration index for each component carrier.

The wireless communication device may be a User Equipment or similar mobile communications device.

The invention may be used to introduce RRC protocol enhancements in order to improve Scheduling Request procedure when multiple PUCCH CCs are SR-configured to serve an LTE CA-enabled UE in connected mode.

The cellular communication system may be an LTE Advanced system and the network element may be an evolved Node B. Multiple Scheduling Request-configured Component Carriers may be offered to a wireless communication device from the same evolved Node B or from different evolved Node Bs (in the case of dual connectivity for example) .

According to a sixth aspect of the invention， there is provided a non-transitory computer readable medium having computer readable instructions stored thereon for execution by a processor to perform the method according to the first and third aspects.

The non-transitory computer readable medium may comprise at least one from a group consisting of： a hard disk， a CD-ROM， an optical storage device， a magnetic storage device， a Read Only Memory， a Programmable Read Only Memory， an Erasable Programmable Read Only Memory， EPROM， an Electrically Erasable Programmable Read Only Memory and a Flash memory.

Advantageously， the invention can provide a reduction of RRC signalling load in systems where multiple Scheduling Request-configured Component Carriers serve a User Equipment. Jointly configuring Scheduling Request indices for Component Carriers in a group optimises the performance of uplink scheduling.

Brief description of the drawings

Further details， aspects and embodiments of the invention will be described， by way of example only， with reference to the drawings. Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. Like reference numerals have been included in the respective drawings to ease understanding.

Figure 1 is a simplified block diagram of a part of a cellular communication system and operating in accordance with an example embodiment.

Figure 2 is a simplified flowchart illustrating a first example of a scheduling configuration method； and

Figure 3 is a simplified flowchart illustrating a second example of a scheduling configuration method.

Detailed description of the preferred embodiments

Those skilled in the art will recognise and appreciate that the specifics of the examples described are merely illustrative of some embodiments and that the teachings set forth herein are applicable in a variety of alternative settings.

Referring now to FIG. 1， an example of part of an LTE cellular communication system operating in accordance with embodiments of the invention is illustrated and indicated generally at 100 and comprises an evolved Node B (eNB) 101. The eNB 101 includes a scheduler 102 and a transceiver 103. The eNB 101 utilises Carrier Aggregation and supports a primary Component Carrier and a secondary Component Carrier which are represented respectively by a primary cell (PCell) 104 and a secondary cell (SCell) 105. In other examples， more than two component carriers may be supported by the eNB 101. A User Equipment (UE) 106 which is CA-enabled is located within the coverage areas of both the primary cell 104 and the secondary cell 105. The transceiver 103 is arranged in a conventional manner to transmit and receive communication signals and data to and from the User Equipment 106. The scheduler 102 is arranged to co-ordinate SR configuration in a manner to be described below.

The eNB 101 communicates with UEs (for example UE106) which are CA-enabled and in connected mode and that can be semi-statically configured with more than one UL CC (i.e. the PCell 104 and UL SCell 105 of the example of Figure 1) . The UEs can also be configured with periodic SR opportunities both on the primary Component Carrier and also on the secondary Component Carrier and have them activated to serve the UE at the same time. The scheduler 102 in the eNB may regularly monitor uplink scheduling load and UE activity and use this information for dynamically adapting SR scheduling parameters between the primary and secondary CCs.

Conventional signalling of per-CC SR indices provides full flexibility for an eNB to control how often and when a UE can get an opportunity for transmitting a SR per CC.The present invention provides enhancements in the sense of limiting the UE-specific information or the information that does not need to be updated or exchanged through the SchedulingRequestConfig IE every time a CC is configured (or re-configured) for a UE.

Typically， a Scheduling Request configuration Information Element for both the primary Component Carrier and a secondary Component Carrier includes a dsr-TransMax value of three bits and a Scheduling Request configuration index of eight bits. The Scheduling Request configuration index controls the SR periodicity and the subframe (SF) offset. Conventionally， the dsr-TransMax value is signalled regardless of whether an update is needed or not. It may not be necessary to update this value for every added secondary Component Carrier and therefore to optimise resources， in a first embodiment， the eNB 101 ensures that the Scheduling Request configuration Information Element (in respect of the secondary CC) which is transmitted to the UE 106 does not contain the dsr-TransMax value. Therefore three bits of data are saved. It will be noted that a dsr-TransMax value has to be initialised in respect of the primary CC： for the UE 106 in order to limit the number of SR retransmissions and to avoid overload. In general， the dsr-TransMax value is used to to improve the reliability of D-SR and force a UE to release SR resources when deemed appropriate.

In a second embodiment a Scheduling Request configuration Information Element includes a group configuration index which is computed by the scheduler 102. A dsr-TransMax value may or may not be included in the Scheduling Request Configuration Information Element in respect of the secondary CC.

In general， where a group of two or more CCs are serving a UE， conventional practice requires that in an event of CC (re) configuration， RRC signalling of ShedulingRequestConfig message should take place for each CC-UE link. In that case， redundant UE-specific information (i.e. the UE identification port number communicated via sr-PUCCH-ResourceIndex and sr-PUCCH-ResourceIndexP1， for example) is exchanged multiple times between eNB and UE. However， such multiple exchanges are unnecessary. Thus， in a second embodiment， a single group SR-configuration index is used instead of multiple per-CC Scheduling Request configuration indices. The group index comprises a bit-map for updating all SR required parameters via RRC signalling from any single link， thus， relieving the system from exchanging redundant information and from different links.

This embodiment can provide an additional advantage in cases where multiple SR-configured carriers are offered from different eNBs to the UE， (e.g. in the case of Dual Connectivity) ， For exam [le， when a group of CCs needs to be jointly SR-configured to improve system performance， and these CCs are not originating only from a single eNB， all eNB schedulers and RRC signalling to a UE at a group reconfiguration stage need to be well synchronised so that all CCs’ SR-related parameters are updated at the same time for the UE. In this second embodiment， the update of all CCs’ SR-related parameters can be done via a single link RRC signalling. Therefore， synchronisation constraints are alleviated.

When more than one CC is SR-configured for a UE， the eNB scheduler will need to coordinate SR opportunities among CCs in order to improve system performance.

For example， to improve UL latency reduction， PCell and PUCCH SCell (s) for a UE may be jointly configured on the SR subframe offset parameter or even on SR periodicity parameter (if permitted by PUCCH/PUSCH load constraints) . In that way， the SR transmission instances originating on each CC can be controlled in coordination with the instances on the other CCs. Thus， if for example the object is to minimise the average SR period waiting time， an interleaving of SR configuration indices could be considered. Essentially， the aforementioned co-ordinated SR configuration can already be performed at an eNB scheduler following the current established procedure while (re) configuring each CC via SchedulingRequestConfig. However， an important issue that arises with this known procedure is the following. If the system needs to have a group of SR-configured CCs configured in a co-ordinated manner， every time an additional SR-configured CC is configured (or an existing one is reconfigured) an SR configuration index needs to be sent for each CC in the group. For X SR-configured CCs (where X is an integer greater than 1) ， this requires an RRC signalling of up to X* (2*11+8+3) bits (i.e. per-CC： 2*11 bits for sr-PUCCH-ResourceIndex and sr-PUCCH-ResourceIndexP1 indicating the UE with the frequency domain resources when 2 antenna ports are available； 8bits for sr-ConfigIndex； and 3bits for dsr-TransMax) . For example， for X＝2 in the example of Figure 1， the total signalling is 66bits.

In order to improve upon this situation， in accordance with one embodiment of the invention， a single group SR-configuration index (gI_SR) is used (instead of I_SR per-CC) to control the periodicity and offset of opportunities to the UE from the whole serving group of SR-configured CCs (the primary CC and the secondary CC in the example of Figure 1) . This index is updated once at the (re) configuration process of a CC and applies to all CCs. Thus， gI_SR can be formed as a bit-map specifying the individual index for each CC； i.e. to cover currently existing periodicities/offsets for X CCs a bit-map of

bits could be used. The operation

refers to the ceiling operation. For X＝3， for example， a minimum of

bits is required to identify a carrier among all 3 carriers.

Therefore， in the example of X＝2， only 18+22+3＝43bits will be needed at every (re) configuration instead of the 66bits of the conventional way. The group configuration index thus permits an already SR-configured CC (for example， the Primary CC of Figure 1) to be jointly reconfigured along with another CC (the secondary CC of Figure 1 for example) ， when the latter is added for dynamic scheduling of a UE.

The RRC signalling reduction benefit becomes even more significant： when considering more than two SR-configured CCs and/or when frequent reconfiguration of PUCCH CCs is taking place.

An example of a bitmap gI_SR for two component carriers (X＝2) ， for example the primary and secondary component carriers (PCC， SCC) of Figure 1， is shown in the table below. Each (integer) entry is eight bits for a range of 158 values. The bitmap is calculated in the scheduler 102.

Reference will now be made to the flow chart of Figure 2 which illustrates a first example of a scheduling configuration method which may be carried out in the system illustrated in Figure 1. At 201， the primary Component Carrier (represented by the cell 104 in Figure 1) is configured in the UE 106 by the eNB 101 transmitting the necessary configuration signalling. This configuration is carried out in accordance with known techniques (including， for example RRC connection procedures) . At 202， a Scheduling Request Configuration for the primary Component Carrier is configured in the UE 106 by the eNB 101 transmitting a Scheduling Request Configuration comprising a Scheduling Request Configuration Information Element. The Scheduling Request Configuration basically informs the UE of the PUCCH resources which will be available on the primary Component Carrier for making a scheduling request. This Information Element includes a Scheduling Request Configuration Index and a dsr-TransMax value. At 203， the secondary Component Carrier (represented by the cell 105 in Figure 1) is configured in the UE 106 by the eNB 101 transmitting the necessary configuration signalling. This configuration is carried out in accordance with known Carrier Aggregation techniques. At 204， a Scheduling Request Configuration for the secondary CC is configured in the UE 106 by the eNB 101 transmitting a Scheduling Request Configuration comprising a Scheduling Request Configuration Information Element. This Scheduling Request Configuration basically informs the UE of the PUCCH resources which will be available on the secondary Component Carrier for making a scheduling request. This Information Element includes a Scheduling Request Configuration Index but in order to save on resources， omits a dsr-TransMax value.

Reference will now be made to the flow chart of Figure 3 which illustrates a second example of a scheduling configuration method which may be carried out in the system illustrated in Figure 1. The primary Component Carrier (represented by the cell 104 in Figure 1) and the secondary Component Carrier (represented by the cell 105 in Figure 1) form a serving group of SR-configurable Component Carriers. At 301， the primary Component Carrier is configured in the UE 106 by the eNB 101 transmitting the necessary configuration signalling. This configuration is carried out in accordance with known techniques (including， for example， RRC connection procedures) . At 302， a first Scheduling Request Configuration in respect of the primary Component Carrier is configured in the UE 106 by the eNB 101 transmitting a Scheduling Request Configuration comprising a first Scheduling Request Configuration Information Element. The Scheduling Request Configuration basically informs the UE of the PUCCH resources which will be available on the primary Component Carrier for making a scheduling request. This Information Element includes a Scheduling Request Configuration Index and a dsr-TransMax value. At 303， the secondary Component Carrier is configured in the UE 106 by the eNB 101 transmitting the necessary configuration signalling. This configuration is carried out in accordance with known Carrier Aggregation techniques. At 304， a second Scheduling Request Configuration is configured in the UE 106 by the eNB 101 transmitting a Scheduling Request Configuration comprising a second Scheduling Request Configuration Information Element. This Scheduling Request Configuration basically informs the UE of the PUCCH resources which will be available on the secondary Component Carrier for making a scheduling request. This second Information Element includes a Scheduling Request Group Configuration Index The group configuration index is generated in the scheduler 102 and comprises a bit-map which specifies the individual configuration index for both the primary Component Carrier and the secondary Component Carrier. By virtue of the use of the group configuration index included in the Scheduling Request Configuration Information Element， no further scheduling request needs to be reconfigured for the primary Component Carrier on configuration of the secondary Component Carrier. Therefore， the resources are saved compared with conventional techniques.

The methods described with reference to Figure 2 and Figure 3 can be applied to cases where the Component Carriers are either licensed or unlicensed. In the unlicensed case， there is the possibility that in future， SR will be provided on more carriers than theoretically necessary in order to mitigate the fact that some carriers may be sensed as busy. In that case， a high number of SR-configured CCs may exist at the same time for a UE， while reconfigurations may happen very often. Thus， the potential reduction of signalling load offered by the invention will become even more significant.

Optionally， more SR opportunities could be offered to a UE on a preferred CC but for a shortened time period by taking into account current UE-CC link conditions. This would effectively reduce latency of first packet uplink transmissions. To implement this option， L1 signalling could be used to update part (or the whole) of the group configuration index.

Optionally， the bit-map comprising the group configuration index may be modified so that the update of the SR periodicity and offset parameters could be made optional for any specified Component Carrier. This option could provide significant benefit in cases where not all CCs in a group need to be reconfigured when a CC is (re) configured. For example， it may be more appropriate for unlicensed carriers (e.g. Licensed Assisted Access CCs) to have fixed or slower configured SR periodicity and offset parameters in order to avoid too frequent reconfigurations due to frequent releases and additions of these CCs.

The signal processing functionality of the embodiments of the invention， particularly the scheduler 102 and eNB 101， may be achieved using computing systems or architectures known to those who are skilled in the relevant art. Computing systems such as， a desktop， laptop or notebook computer， hand-held computing device (PDA， cell phone， palmtop， etc. ) ， mainframe， server， client， or any other type of special or general purpose computing device as may be desirable or appropriate for a given application or environment can be used. The computing system can include one or more processors which can be implemented using a general or special-purpose processing engine such as， for example， a microprocessor， microcontroller or other control module.

The computing system can also include a main memory， such as random access memory (RAM) or other dynamic memory， for storing information and instructions to be executed by a processor. Such a main memory also may be used for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor. The computing system may likewise include a read only memory (ROM) or other static storage device for storing static information and instructions for a processor.

The computing system may also include an information storage system which may include， for example， a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media， such as a hard disk drive， a floppy disk drive， a magnetic tape drive， an optical disk drive， a compact disc (CD) or digital video drive (DVD) read or write drive (R or RW) ， or other removable or fixed media drive. Storage media may include， for example， a hard disk， floppy disk， magnetic tape， optical disk， CD or DVD， or other fixed or removable medium that is read by and written to by media drive. The storage media may include a computer-readable storage medium having particular computer software or data stored therein.

In alternative embodiments， an information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include， for example， a removable storage unit and an interface ， such as a program cartridge and cartridge interface， a removable memory (for example， a flash memory or other removable memory module) and memory slot， and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to computing system.

The computing system can also include a communications interface. Such a communications interface can be used to allow software and data to be transferred between a computing system and external devices. Examples of communications interfaces can include a modem， a network interface (such as an Ethernet or other NIC card) ， a communications port (such as for example， a universal serial bus (USB) port) ， a PCMCIA slot and card， etc. Software and data transferred via a communications interface are in the form of signals which can be electronic， electromagnetic， and optical or other signals capable of being received by a communications interface medium.

In this document， the terms ‘computer program product’ ， ‘computer-readable medium’ and the like may be used generally to refer to tangible media such as， for example， a memory， storage device， or storage unit. These and other forms of computer-readable media may store one or more instructions for use by the processor comprising the computer system to cause the processor to perform specified operations. Such instructions， generally referred to as ‘computer program code’ (which may be grouped in the form of computer programs or other groupings) ， when executed， enable the computing system to perform functions of embodiments of the present invention. Note that the code may directly cause a processor to perform specified operations， be compiled to do so， and/or be combined with other software， hardware， and/or firmware elements (e.g.， libraries for performing standard functions) to do so.

In an embodiment where the elements are implemented using software， the software may be stored in a computer-readable medium and loaded into computing system using， for example， removable storage drive. A control module (in this example， software instructions or executable computer program code) ， when executed by the processor in the computer system， causes a processor to perform the functions of the invention as described herein.

Furthermore， the inventive concept can be applied to any circuit for performing signal processing functionality within a network element. It is further envisaged that， for example， a semiconductor manufacturer may employ the inventive concept in a design of a stand-alone device， such as a microcontroller of a digital signal processor (DSP) ， or application-specific integrated circuit (ASIC) and/or any other sub-system element.

It will be appreciated that， for clarity purposes， the above description has described embodiments of the invention with reference to a single processing logic. However， the inventive concept may equally be implemented by way of a plurality of different functional units and processors to provide the signal processing functionality. Thus， references to specific functional units are only to be seen as references to suitable means for providing the described functionality， rather than indicative of a strict logical or physical structure or organisation.

Aspects of the invention may be implemented in any suitable form including hardware， software， firmware or any combination of these. The invention may optionally be implemented， at least partly， as computer software running on one or more data processors and/or digital signal processors or configurable module components such as FPGA devices. Thus， the elements and components of an embodiment of the invention may be physically， functionally and logically implemented in any suitable way. Indeed， the functionality may be implemented in a single unit， in a plurality of units or as part of other functional units.

Although the present invention has been described in connection with some embodiments， it is not intended to be limited to the specific form set forth herein. Rather， the scope of the present invention is limited only by the accompanying claims. Additionally， although a feature may appear to be described in connection with particular embodiments， one skilled in the art would recognize that various features of the described embodiments may be combined in accordance with the invention. In the claims， the term ‘comprising’ does not exclude the presence of other elements or steps.

Furthermore， although individually listed， a plurality of means， elements or method steps may be implemented by， for example， a single unit or processor. Additionally， although individual features may be included in different claims， these may possibly be advantageously combined， and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Also， the inclusion of a feature in one category of claims does not imply a limitation to this category， but rather indicates that the feature is equally applicable to other claim categories， as appropriate.

Furthermore， the order of features in the claims does not imply any specific order in which the features must be performed and in particular the order of individual steps in a method claim does not imply that the steps must be performed in this order. Rather， the steps may be performed in any suitable order. In addition， singular references do not exclude a plurality. Thus， references to ‘a’ ， ‘an’ ， ‘first’ ， ‘second’ ， etc. do not preclude a plurality.

Although the present invention has been described in connection with some embodiments， it is not intended to be limited to the specific form set forth herein. Rather， the scope of the present invention is limited only by the accompanying claims. Additionally， although a feature may appear to be described in connection with particular embodiments， one skilled in the art would recognise that various features of the described embodiments may be combined in accordance with the invention. In the claims， the term ‘comprising’ or “including” does not exclude the presence of other elements.

Claims

A scheduling configuration method in a cellular communication system which supports Carrier Aggregation, the method including: transmitting a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system, transmitting a first Scheduling Request configuration wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a first Scheduling Request configuration index and a dsr-TransMax value； transmitting a secondary Component Carrier configuration for reception by the wireless communication device, transmitting a second Scheduling Request configuration wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a second Scheduling Request configuration index but does not include a dsr-TransMax value.
A network element which supports a primary Component Carrier and a secondary Component Carrier in a cellular communication system which supports Carrier Aggregation, the network element being arranged to transmit a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system, transmit a first Scheduling Request configuration for reception by the wireless communication device wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a first Scheduling Request configuration index and a dsr-TransMax value； transmit a secondary Component Carrier configuration for reception by the wireless communication device, transmit a second Scheduling Request configuration for reception by the wireless communication device, wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a second Scheduling Request configuration index but does not include a dsr-TransMax value.
A scheduling configuration method in a cellular communication system which supports Carrier Aggregation, the method including: transmitting a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system, transmitting a first Scheduling Request configuration wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a Scheduling Request configuration index and a dsr-TransMax value, transmitting a secondary Component Carrier configuration for reception by the wireless communication device, transmitting a second Scheduling Request configuration, wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a Scheduling Request group configuration index which specifies an individual configuration index for each Component Carrier.
The method of claim 3 wherein the second Scheduling Request Information Element includes a dsr-TransMax value.
The method of claim 3 wherein the second Scheduling Request Information Element does not include a dsr-TransMax value.
The method of any of claims 3 to 5 wherein the Scheduling Request group configuration index comprises a bitmap which specifies an individual configuration index for each Component Carrier.
A network element which supports a primary Component Carrier and a secondary Component Carrier in a cellular communication system which supports Carrier Aggregation, the network element being arranged to: transmit a primary Component Carrier configuration for reception by a wireless communication device located in the cellular communication system, transmit a first Scheduling Request configuration wherein the first Scheduling Request configuration comprises a first Scheduling Request Information Element which includes a Scheduling Request configuration index and a dsr-TransMax value, transmit a secondary Component Carrier configuration for reception by the wireless communication device, transmit a second Scheduling Request configuration wherein the second Scheduling Request configuration comprises a second Scheduling Request Information Element which includes a Scheduling Request group configuration index which specifies an individual configuration index for each Component Carrier.
A wireless communication device for use in a cellular communication system, wherein the wireless communication device is arranged to: receive primary and secondary Component Carrier configurations, receive first and second Scheduling Request configuration Information Elements from a network element of the cellular communication system in respect of the primary and secondary Component Carriers, and configure Scheduling Requests in accordance with the received first and second Scheduling Request configuration Information Elements, wherein the second Scheduling Request configuration Information Element includes a Scheduling Request group configuration index specifying an individual configuration index for each component carrier.
A non-transitory computer readable medium having computer readable instructions stored thereon for execution by a processor to perform the method according to either of claims 1 or 3.
The non-transitory computer readable medium of claim 9 comprising at least one from a group consisting of: a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory, a Programmable Read Only Memory, an Erasable Programmable Read Only Memory, EPROM, an Electrically Erasable Programmable Read Only Memory and a Flash memory.