WO2021022523A1

WO2021022523A1 - Resource scheduling in relay communication

Info

Publication number: WO2021022523A1
Application number: PCT/CN2019/099666
Authority: WO
Inventors: Gang Wang
Original assignee: Nec Corporation
Priority date: 2019-08-07
Filing date: 2019-08-07
Publication date: 2021-02-11

Abstract

Embodiments of the present disclosure relate to resource scheduling in relay communication. A method for communication comprises determining, at a relay device, a target buffer size of uplink data of at least one terminal device that is buffered at the relay device. The method also comprises determining, from a mapping between buffer sizes and indices, at least one index to indicate a buffer size equal to or smaller than the target buffer size by comparing the target buffer size and an upper limit of buffer size that is allowable be reported to an upstream device. The upper limit of buffer size is greater than a further upper limit of buffer size configured for the at least one terminal device. The method further comprises transmitting the at least one determined index to the upstream device to request an uplink resource for transmission of the buffered uplink data to the upstream device.

Description

RESOURCE SCHEDULING IN RELAY COMMUNICATION

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to resource scheduling in relay communication.

BACKGROUND

Communication technologies have been developed in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of an emerging telecommunication technology is new radio (NR) , for example, the fifth generation (5G) radio access. 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoTs) ) , and other requirements. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standards.

In order to deal with an intensive cell configuration in the fifth generation (5G) of the communication system according to 3GPP and to reduce deployment of backhaul optical fibers, integrated access and backhaul (IAB) of a communication system has been developed to support relay communication. For example, in 5G IAB, a relay node may be deployed in a communication network to simply backhaul complexity of the communication network and increase spectral efficiency and system capacity of a hotspot area. In a communication system comprising relay nodes, terminal devices accesses network devices via one or more relay nodes, such as IAB nodes in 5G IAB. For the scenario of relay networking, especially in the scenario of multi-hop relay, how to improve resource scheduling is a technical problem to be solved.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of resource scheduling in relay communication.

In a first aspect, there is provided a method for communication. The method comprises determining, at a relay device, a target buffer size of uplink data of at least one terminal device that is buffered at the relay device; determining, from a first mapping between a first set of buffer sizes and a first set of indices, at least one index to indicate a buffer size equal to or smaller than the target buffer size by comparing the target buffer size and a first upper limit of buffer size that is allowable be reported to an upstream device, the first upper limit of buffer size being greater than a second upper limit of buffer size configured for the at least one terminal device; and transmitting the at least one determined index to the upstream device to request an uplink resource for transmission of the buffered uplink data to the upstream device.

In a second aspect, there is provided a method for communication. The method comprises receiving, at a relay device and from an upstream device, control information indicating an uplink resource allocated to the relay device; determining whether the uplink resource is dedicated to at least one terminal device or at least one logical channel of the relay device; in response to determining that the uplink resource is dedicated to the at least one terminal device, transmitting uplink data of the at least one terminal device to the upstream device using the uplink resource; and in response to determining that the uplink resource is dedicated to the at least one logical channel, transmitting uplink data corresponding to the at least one logical channel to the upstream device using the uplink resource.

In a third aspect, there is provided a method for communication. The method comprises receiving, at an upstream device of a relay device and from the relay device, a request for an uplink resource for transmission of uplink data of at least one terminal device; in response to the request, determining whether an uplink resource is to be dedicated to the at least one terminal device or at least one logical channel of the relay device; and transmitting, based on the determining, control information indicating the uplink resource to the relay device.

In a fourth aspect, there is provided a method for communication. The method comprises determining, at a master device of a relay device, whether a terminal device accesses the master device via the relay device, the relay device being configured to transmit uplink data of the terminal device towards the master device; and configuring, based on the determining, a prioritized bit rate (PBR) to a logical channel of the terminal device that is available for data transmission.

In a fifth aspect, there is provided a relay device. The relay device includes a processing unit; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to the first aspect.

In a sixth aspect, there is provided a relay device. The relay device includes a processing unit; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to the second aspect.

In a seventh aspect, there is provided a communication device. The communication device includes a processing unit; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to the third aspect.

In a eighth aspect, there is provided a master device. The master device includes a processing unit; and a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to the fourth aspect.

In a ninth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the first aspect.

In a tenth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the second aspect.

In a eleventh aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the third aspect.

In a twelfth aspect, there is provided a computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to the fourth aspect.

Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:

Fig. 1 is a block diagram of a communication system in which embodiments of the present disclosure can be implemented;

Fig. 2 is a signaling chart illustrating a process of resource scheduling according to an embodiment of the present disclosure;

Fig. 3 is a signaling chart illustrating a process of resource scheduling according to a further embodiment of the present disclosure;

Fig. 4 is a schematic diagram illustrating an example medium access control (MAC) control element (CE) according to an embodiment of the present disclosure;

Fig. 5 is a signaling chart illustrating a process of resource scheduling according to a yet further embodiment of the present disclosure;

Fig. 6 is a flowchart of an example method in accordance with an embodiment of the present disclosure;

Fig. 7 is a flowchart of an example method in accordance with an embodiment of the present disclosure;

Fig. 8 is a flowchart of an example method in accordance with an embodiment of the present disclosure;

Fig. 9 is a flowchart of an example method in accordance with an embodiment of the present disclosure; and

Fig. 10 is a simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitations as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

As used herein, the term “network device” refers to a device which is capable of providing or hosting a cell or coverage where terminal devices can communicate. Examples of a network device include, but not limited to, a Node B (NodeB or NB) , an Evolved NodeB (eNodeB or eNB) , a NodeB in new radio access (gNB) a Remote Radio Unit (RRU) , a radio head (RH) , a remote radio head (RRH) , a low power node such as a femto node, a pico node, and the like. For the purpose of discussion, in the following, some embodiments will be described with reference to eNB as examples of the network device.

As used herein, the term “terminal device” refers to any device having wireless or wired communication capabilities. Examples of the terminal device include, but not limited to, user equipment (UE) , personal computers, desktops, mobile phones, cellular phones, smart phones, personal digital assistants (PDAs) , portable computers, tablets, wearable devices, internet of things (IoT) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, device on vehicle for V2X communication where X means pedestrian, vehicle, or infrastructure/network, or image capture devices such as digital cameras, gaming devices, music storage and playback appliances, or Internet appliances enabling wireless or wired Internet access and browsing and the like. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

In one embodiment, the terminal device may be connected with a first network device and a second network device. One of the first network device and the second network device may be a master node and the other one may be a secondary node. The first network device and the second network device may use different radio access technologies (RATs) . In one embodiment, the first network device may be a first RAT device and the second network device may be a second RAT device. In one embodiment, the first RAT device is eNB and the second RAT device is gNB. Information related with different RATs may be transmitted to the terminal device from at least one of the first network device and the second network device. In one embodiment, first information may be transmitted to the terminal device from the first network device and second information may be transmitted to the terminal device from the second network device directly or via the first network device. In one embodiment, information related with configuration for the terminal device configured by the second network device may be transmitted from the second network device via the first network device. Information related with reconfiguration for the terminal device configured by the second network device may be transmitted to the terminal device from the second network device directly or via the first network device.

Communications discussed herein may use conform to any suitable standards including, but not limited to, New Radio Access (NR) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , cdma2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies.

As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below.

In some examples, values, procedures, or apparatus are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

Fig. 1 shows an example communication system 100 in which implementations of the present disclosure can be implemented. The communication system 100 is shown as a relay networking system, which can include one or more relay devices 110-1, 110-2, 110-3, 110-4 (collective or individually referred to as relay devices 110 hereinafter) , one or more terminal devices 120-1, 120-2, 120-3, 120-4 (collective or individually referred to as terminal devices 120 hereinafter) , and a network device 130.

In the communication system 100, the relay devices 110 and the network device 130 provide a wireless connection to the terminal devices 120 within the coverage thereof. The relay devices 110 are deployed to relay communications between one or more terminal devices 120 and the network device 130. A terminal device 120 accesses a relay device 110 using an access link from the terminal device 120 to the relay device 110, so as to enable wireless or wired bidirectional communication with the relay device 110. The relay device 110 is configured to provide a backhaul service for one or more terminal devices 120 connected therewith and access the network device 130 using a backhaul link from the relay device 110 to the network device 130, so as to enable wireless or wired bidirectional communication with the network device 130. The relay device 110 may relay data from the terminal device 120 towards the network device 130 via zero, one, or more other relay devices 110. That is, the terminal device 120 may communicate with the network device 130 via one or more hops through one or more relay devices 110.

The network device 130 may further communicate with a corner network (CN) (not shown) using a backhaul link. In addition to the communication with the relay delays 110 and possibly with terminal devices 120, the network device 130 may further include other network elements or network entities, such as an access management unit, a session management unit, a control plane unit, a user plane unit, and other function units. The embodiments of the present disclosure are not limited in this regard.

Communication in a direction from a terminal device 120 towards the network device 130 is referred to as uplink (UL) communication, while communication in a direction from the network device 130 towards a terminal device 120 is referred to as downlink (DL) communication. A relay device 110 may sometimes be referred to as a backhaul device or a backhaul node. For example, the relay device 110 may be a wireless backhaul node in a 5G network, which may be referred to as an integrated access and backhaul (IAB) node. There are other names for the relay device 110, which are not specifically limited in the embodiment of the present application.

The relay devices 110 are connected to a donor network device (such as donor gNodeB, DgNB) , in the example of Fig. 1, the network device 130. The network device 130 may control some behaviors of the relay devices 110. Such network device 130 may also be referred to as a master device of the relay devices 110. In the examples of IAB nodes, the network device 130 may also be referred to as an IAB-donor.

The relay devices 110 and the network device 130 may have a certain hierarchical relationship. The relay device 110 may appear as a network device when communicating with a parent device (e.g., a network device 130 or another relay device 110) ; and the functionalities of the relay device 110 for communication with the parent device may be referred to as a mobile terminal (MT) . The relay device 110 may appear as a terminal device (i.e., UE) when communicating with a child device (e.g., a terminal device 120 or another relay device 110) ; and the functionalities of the relay device 110 for communication with the child device may be referred to as a data unit (DU) . For example, when communicating with the terminal devices 120-3 and 120-4, the relay device 110-3 may act as a network device (base station) . The communication from the terminal devices 120-3 and 120-4 to the relay device 110-3 is UL backhaul communication, and the communication in a reverse direction is DL backhaul communication. When communicating with the relay device 110-2, the relay device 110-3 may act as a terminal device (i.e., UE) . Communication from the relay device 110-3 to the relay device 110-2 is also UL backhaul communication, and the communication in a reverse direction is DL backhaul communication.

Hereinafter, for a given device, a device from which the given device receives data may be referred to a downstream device of the given device, while a device to which the given device transmits data may be referred to as an upstream device. In UL communication from a terminal device towards a network device, depending on the network topology, a downstream device of a relay device 110 may be a terminal device or another relay device from which it may receive UL data of the terminal device 120 to be transmitted, an upstream device of the relay device 110 may be a relay device or a network device to which it may transmit the UL data.

As mentioned above, a relay device 110 may be connected with one or more terminal devices 120 to relay their UL data to the network device 130, or may be connected with one or more relay devices 110 in the multi-hop relay scenario. Such multi-hop relay has just been approved in the IAB architecture in order to provide benefits in different deployment and traffic scenarios. In UL backhaul communication with the downstream devices (terminal devices 120 and/or other relay devices 110) , a relay device 110 may schedule resources to the downstream devices for UL data transmission.

It would be appreciated that the respective numbers of the network devices, relay devices and terminal devices, as shown in Fig. 1, are provided merely for illustration, without any intention for limitation. The communication system 100 may include any respective appropriate numbers of network devices, relay devices and terminal devices, and the communication connection established among the terminal devices, the relay device, and the network device may be varied in different application cases. For example although not shown, a terminal device may communicate with the network device via two or more hops through the relay architecture. In addition, one or more terminal devices may establish direction connections with the network device without relying on the relay devices in the communication system 100.

It would also be appreciated that for simplicity of discussion, the network device 130 is shown to be a destination network device of UL transmission from the terminal device 120 and a master device of the relay devices 110 in the example of Fig. 1. In other embodiments, a destination network device of UL transmission the master device and a master device of the relay devices may be two different network devices. The scope of the present disclosure is not limited in this regard.

In UL communication, a device with resources granted will allocate the resources to transmit UL data on respective LCHs. Currently, a token bucket algorithm can be applied for resource allocation. Specifically, a medium access control (MAC) entity of the device shall maintain a variable Bj for each logical channel (LCH) j. Bj shall be initialized to zero when the related LCH is established and incremented by the product PBR×TTI duration for each TTI, where PBR is a Prioritized Bit Rate of the LCH j. However, the value of Bj can never exceed the bucket size and if the value of Bj is larger than the bucket size of logical channel j, it shall be set to the bucket size. The bucket size of a LCH is equal to PBR×BSD, where BSD is Bucket Size Duration (BSD) , PBR and BSD are configured by upper layers.

During resource allocation, all the LCHs with Bj > 0 are allocated resources in a decreasing priority order. As such, the token bucket algorithm makes sure that the high priority LCH is prioritized. If the PBR of a LCH is set to “infinity” , the MAC entity shall allocate resources for all the data that is available for transmission on the LCH before meeting the PBR of the lower priority LCHs. Thus, the LCH with a PBR of “infinity” will be scheduled overwhelmingly, while LCHs with low priorities may be starved for resources.

In direct communication between a terminal device and a network device, the imbalance between the LCH with the PBR of “infinity” and other LCHS may not be obvious because the “infinity” PBR is not always configured for the terminal device. Even if the PBR of “infinity” is configured, the network device may not configured more than one LCH with the PRB of “infinity” for a single terminal device. Thus, there is usually granted UL resource left for other LCH after the data on the LCH with the PBR of “infinity” has been transmitted. However, in the relay architecture such as the one shown in Fig. 1, in the MT of the relay device acting as a terminal device, there is a higher probability of having a LCH with the PBR of “infinity. ” This is because the relay device may be connected with a larger number of terminal devices or probably a larger number of other relay devices.

There is no efficient resource scheduling mechanism that can be applied in a relay device to avoid resources drained out by one or more specific LCHs and to avoid hindering resources allocated to data in LCHs with relatively lower priorities.

According to embodiments of the present disclosure, there are proposed some solutions of resource scheduling in relay communication. In one of the solutions, a buffer size to be reported to request for resource allocation is enlarged for a relay device. More specifically, an upper limit of buffer size to be reported by the relay device is set to be greater than an upper limit of buffer size configured for a terminal device connected to the relay device. Thus, the relay device can report any buffer size within its upper limit to an upstream device to request for an UL resource for UL transmission. As such, even if the relay device is connected with a large number of terminal devices, it is possible to request more UL resources to relay UL data of those terminal devices to the upstream device. The more granted UL resources make all the LCHs of the relay device have higher probabilities of being allocated with resources for transmission.

Some embodiments of the present disclosure will be described in detail below with reference to Fig. 2, which shows a process 200 of resource scheduling. For the purpose of discussion, the process 200 will be described with reference to Fig. 1. The process 200 may involve one or more terminal devices 120, a relay device 110, and an upstream device of the relay device 110 in Fig. 1. The process 200 is related to resource scheduling for UL transmission from the terminal device 120 towards the network device 130. Thus, the upstream device of the relay device 110 may be another relay device 110 or the network device 130. For example, if the process 200 involves the relay device 110-3, the upstream device may be the relay device 110-2. If the process 200 involves the relay device 110-1 (or the relay device 110-2) , its upstream device may be the network device 130.

In operation, the relay device 110 may receive 205 UL data of one or more terminal devices 120 to be relayed to the network device 130. The relay device 110 may be directly connected with the one or more terminal devices 120 and then receive the UL data using an access link (s) . Alternatively, the relay device 110 may be directly connected with the one or more relay devices 110 and then receive the UL data relayed by those relay devices 110 using a backhaul link (s) .

The relay device 110 buffers the received UL data of the terminal device (s) 120. The UL data of the terminal device (s) 120 may correspond to on one or more LCHs of the terminal device (s) 120. In the relay device 110, the relay device 110 may also establish a number of LCHs for the UL data. LCHs of the respective terminal device (s) may be mapped to the LCHs of the relay device 110.

To transmit the UL data to an upstream device, the relay device 110 may act as a terminal device (i.e., the MT) and may request its

upstream device

110 or 130 for UL resources scheduled. In the procedure of resource scheduling, similarly as a terminal device, the relay device 110 needs to report its buffer size of the UL data to the

upstream device

110 or 130 so that the

upstream device

110 or 130 can decide the amount of UL resources to be granted based on the buffer size. The report of the buffer size may be triggered according to some predefined criteria. In some embodiments, unlike a normal terminal device which does not report the buffer size unless there is data in a L2 buffer for UL transmission, the relay device 110 may report the buffer size in a more frequent way since there may be a large number of terminal devices attached, especially when the relay device is deployed closer to the network device 130. The predefined criteria for triggering the report of the buffer size are not limited in the present disclosure and any other criteria may be possible.

In the case that the relay device 110 decides to report its buffer size, it determines 210 a target buffer size of buffered UL data of the one or more terminal devices 120. The target buffer size may be a total amount of buffered UL data in all active LCHs of the relay device 110 or may be a total amount of buffered UL data in a logical channel group (LCH) consisting of one or more LCHs. Since the relay device 110 may directly connect to a number of terminal devices 120 and/or probably indirectly connect to a number of further terminal devices 120 via one or more other relay devices, the amount of buffered UL data of the terminal devices 120 may be much larger as compared to a size of buffered UL data in a single terminal device 120. In some cases, even if the relay device 110 is directly or indirectly connected to a smaller number of terminal devices, due to different periods of reporting buffer sizes, the amount of buffered UL data at the relay device 110 may also be increased. Thus, it is expected to require more UL resources for transmission of the buffered UL data by the relay device 110.

In the process 200, the relay device 110 further determines 215 at least one index to indicate a buffer size equal to or smaller than the target buffer size by comparing the target buffer size and an upper limit of buffer size that is allowable be reported to the

upstream device

110 or 130. For ease of discussion, the upper limit of buffer size for the relay device 110 is sometimes referred to as a first upper limit of buffer size hereinafter.

The first upper limit of buffer size is a maximum buffer size that is allowed to report to the

upstream device

110 or 130 for requesting resources. In embodiments of the present disclosure, the upper limit of buffer size configured for the relay device 110 is at least greater than an upper limit of buffer size configured for the terminal device 120. For ease of discussion, the upper limit of buffer size for the terminal device 120 is sometimes referred to as a second upper limit of buffer size hereinafter. That is, the maximum allowable buffer size of the relay device 110 is enlarged as compared to that of the terminal device 120.

Generally, upper limits of buffer size are configured as the same for all the terminal devices 120 and are known to the relay device 110 and the network device 130. For example, the second upper limit of buffer size is set to 81 MB, which means that each time a terminal device 120 is allowed to report a buffer size up to 81 MB. The inventors has found that the same upper limit of buffer size used by the relay device 110 may result in a limited amount of UL resources to be granted which might not be enough to transmit all the buffered data. Due to the limited granted resources, data on a LCH with a PBR of “infinity” will consume most of the granted resources in some cases and no resources are left for transmission of data on other LCHs with lower priorities. In addition, a smaller upper limit of buffer size set for the relay device 110 may cause the relay device 110 continuously reporting its buffer size, resulting in more signaling overhead.

In view of the above, according to embodiments of the present disclosure, the first upper limit of buffer size at the relay device 110 is enlarged to be at least greater than the second upper limit of buffer sizes used by the terminal device 120 (for example, larger than 81 MB) . In some embodiments, the upper limit of buffer size may be the same for relay devices 110 in the system 100. In some embodiments, a different upper limit of buffer sizes may be configured depending on a location of a relay device 110 with respect to the network device 130. In an embodiment, if the relay device 110 receives the buffered UL data from one or more downstream relay devices 110, the first upper limit of buffer size may be greater than an upper limit of buffer size configured for the downstream relay devices 110. That is, the closer the relay device 110 is to the network device 130, the greater the upper limit of buffer size is. As such, those relay devices 110 closer to the network device 130 may be able to request more UL resources by reporting a larger buffer size.

The one or more indices to be reported are determined by the relay device 110 from a predetermined mapping (referred to as a “first mapping” for ease of discussion) between a first set of buffer sizes and a first set of indices. The first mapping may be stored at the relay device 110 as a mapping table. The relay device 110 may search for the mapping table to find one or more indices to indicate a buffer size to the

upstream device

110 or 130. In some embodiments, depending on the comparing result, the relay device 110 is allowed to indicate a buffer size to the

upstream device

110 or 130. Specifically, if the target buffer size is within (i.e., equal to or smaller than) the first upper limit of buffer size, the relay device 110 may determine at least one index to indicate the target buffer size. Otherwise, if the target buffer size exceeds the first upper limit of buffer size, the relay device 110 may determine at least one index to indicate the first upper limit of buffer size (i.e., the maximum allowable buffer size) instead of the target buffer size.

In some embodiments, the first mapping may be fixed at the relay device 110 as a mapping table. That is, the relay device 110 is configured with a dedicated mapping between buffer sizes and indices. The maximum buffer size in the mapping may be considered to be the first upper limit of buffer size.

In some embodiments, the first mapping may be semi-dynamically configured by the network device 130, which is the master (donor) device of the relay device 110. The relay device 110 may receive, from the network device 130, configuration information for configuring the first mapping. In this case, the relay device 110 may have been configured with a mapping (referred to as a “second mapping” for ease of discussion) between a second set of buffer sizes and a second set of indices. In some examples, such second mapping may be the same as the mapping used by the terminal device 120, or may be a different mapping that having a higher maximum buffer size than the one in the mapping of the terminal device 120.

The relay device 110 may receive, from the network device 130, an indication of an enlargement factor (referred to as a first enlargement factor) which is greater than one as the configuration information. The relay device 110 can determine the first mapping for use by multiplying the second set of buffer sizes in the previously-configured second mapping by the first enlargement factor. As such, each of the buffer sizes is enlarged by the enlargement factor. The mapping between the enlarged buffer sizes (i.e., the first set of buffer sizes) and the indices remains unchanged when determining the first mapping. That is, in the first mapping, the first set of buffer sizes are respectively multiples of the second set of buffer sizes while the first set of indices are the same as the second set of indices. As such, the first upper limit of buffer size (i.e., the maximum allowable buffer size in the first mapping) may be a multiple of the maximum allowable buffer size in the previously-configured second mapping.

The network device may configure the enlargement of the buffer sizes at the relay device 110 upon request or upon detection of a certain event (for example, a larger number of active terminal devices) . In an embodiment, the indication of the first enlargement factor may be configured by the network device 130 via radio resource control (RRC) signaling for configuring the mapping between buffer sizes and indices. The RRC singling from the network device 130 may indicate to the relay device 110 whether the mapping shall be configured as the legacy one (such as the second mapping) or an extended table. In the case of indicating the extended table, the RRC signaling may further indicate the first enlargement factor. The first enlargement factor may be set as any number greater than one, such as 2, 4, 8, 16, or any other value.

Since the relay device 110 may be configured with two or more mappings between buffer sizes and indices (such as the first mapping between the first set of buffer sizes and the first set of indices and the second mapping between the second set of buffer sizes and the second set of indices) , the network device 130 may transmit an enabling indication to the relay device 110 semi-dynamically or periodically to indicate which mapping is enable for use. For example, in response to receiving an enabling indication that the first mapping is enabled, the relay device 110 can determine the one or more indices based on the enabled first mapping. It would be appreciated that instead of configuring the enlargement factor, the relay device 110 may be configured with more than one mapping between different buffer sizes and different indices, one of the mappings may be the same as the one used by the terminal device 120 while the other mappings may indicate larger maximum buffer sizes. The relay device 110 may decide which mapping to use depending on an enabling indication received from the network device 130.

In some embodiments, the change of the mapping used at a certain relay device 110 may be notified to one or more upstream relay devices 110 to which the relay device 110 reports the buffer size such that the upstream relay devices 110 can be able to interpret the buffer size based on the received index (indices) . For example, in addition to indicating the first enlargement factor to the relay device 110, the network device 110 also transmits an indication of the first enlargement factor to one or more upstream relay devices 110 (the upstream relay device 110-2 if the relay device 110 is the relay device 110-3) .

The upstream relay devices 110 may update the mapping between buffer sizes and indices used by that relay device 110 based on the first enlargement factor in a similar manner as described above. Similarly, if a certain relay device 110 is an upstream relay device of one or more further downstream relay devices 110, this relay device 110 may receive, from the network device 130, an indication of an enlargement factor (referred to as a “second enlargement factor” ) , which is the one configured to the downstream relay device 110 for determining a new mapping (referred to as a “third mapping” sometimes hereinafter for ease of discussion) between a third set of buffer sizes and a third set of indices for use. As such, the relay device 110 can also determine the new third mapping to be used by the one or more downstream relay devices 110. It would be appreciated that for a given relay device 110, the third mapping used at the downstream relay device 110 may indicate different buffer sizes, different indices, and/or a different mapping from the first mapping used at the given relay device 110.

In the embodiments described above, the first upper limit of buffer is determined as the maximum buffer size in the first mapping. The relay device 110 may compare the target buffer size with the maximum buffer size in the first mapping to determine one index to indicate the target buffer size or the maximum buffer size (in the case of the target buffer size exceeding the upper limit) .

In some embodiments, instead of enlarging the buffer sizes in the mapping, the relay device 110 is capable of transmitting more than one index to indicate a buffer size equal to or smaller than the first upper limit of buffer size. That is to say, the relay device 110 can transmit two or more indices in one report to the

upstream device

110 or 130. The indicated buffer size may be a sum of buffer sizes mapped to the two or more transmitted indices.

The maximum number of indices allowable to be transmitted in one report may be predetermined, for example. In this case, the first mapping between buffer sizes and indices used by the relay device 110 may be the same as the one used by the terminal device 120. As such, the maximum buffer size in the first mapping may be the same as the second upper limit of buffer size for the terminal device 120. However, the first upper limit of buffer size to be reported by the relay device 110 is a product of the maximum buffer size in the first mapping and the maximum number of indices allowable to be transmitted. For example, if the maximum buffer size in the first mapping is 81 MB and two indices can be transmitted in one report, the first upper limit of buffer size is 162 MB (81 MB x 2) .

In determining the indices to indicate the buffer size, the relay device 110 may compare the target buffer size with a maximum buffer size in the first mapping. If the target buffer size exceeds the maximum buffer size, the relay device 110 selects two or more indices (depending on the maximum allowable number) in the first mapping. The selection of the indices may also depend on the comparing result of the target buffer size and the first upper limit of buffer size. If the target buffer size is within the first upper limit of buffer size, the indices are selected such that a sum of buffer sizes mapped to the selected indices is equal to the target buffer size. If the target buffer size is larger than the first upper limit of buffer size, the indices are selected such that a sum of buffer sizes mapped to the selected indices is equal to the first upper limit of buffer size.

In some embodiments where the target buffer size is small, for example, smaller than or equal to the maximum buffer size in the first mapping, the relay device 110 may select one index in the first mapping to indicate such target buffer size. It would be appreciated that in some embodiments of selecting more than one index to report a buffer size, the first mapping may also be a mapping of enlarged buffer sizes and indices. That is, in addition to enlargement of respective buffer sizes in the mapping table, a relay device 110 is also capable of transmitting more indices in one report to indicate the size of buffered UL data to be transmitted.

Still referring to Fig. 2, upon determining of the one or more indices, the relay device 110 transmits 220 the at least one index to the

upstream device

110 or 130 to request an UL resource for transmission of buffered UL data to the

upstream device

110 or 130. In some embodiments, the at least one index may be transmitted in a buffer status report (BSR) to the

upstream device

110 or 130. The at least one index may be carried in one or more control elements (CEs) , such as in one or more MAC CEs included in a MAC packet data unit (PDU) . In the example of reporting one index, one MCE CE is included to report that index (for example, one BSR) . In the example of more than one index allowable to be transmitted, two or more indices (for example, two or more BSRs) may be carried in one MAC CE. Alternatively, two or more MAC CEs may be included to carry the two or more indices (for example, two or more BSRs) , respectively, in one MAC PDU.

The

upstream device

110 or 130 may, upon receiving the determined index, determine the reported buffer size based on the first mapping that is currently used at the relay device 110. The

upstream device

110 or 130 may decide the amount of UL resources to be scheduled to the relay device 110 based on the reported buffer size. Generally, in order to ensure the resource utilization, the

upstream device

110 or 130 may grant an amount of UL resources that are just enough to transmit the reported buffer size of UL data. However, the

upstream device

110 or 130 may schedule the resources according to any criteria based on the reported buffer size depending on actual implementations. The scope of the present disclosure is not limited in this regard.

In the embodiments described above, the relay device 110 is allowed to report a larger buffer size to request more UL resources from the

upstream device

110 or 130 in one BSR. As such, UL data in respective LCHs of the relay device 110 have higher probabilities of being transmitted even in presence of a LCH with a PRB of “infinity. ”

In a further solution in accordance of some embodiments of the present disclosure, instead of granting UL resources to a relay device (a MT of the relay device) , UL resources granted by an upstream device to the relay device may be in a fine-grained manner. Specifically, in granting an UL resource to a relay device, an upstream device determines whether the UL resource is dedicated to at least one terminal device or at least one LCH of the relay device. The upstream device transmits control information indicating the UL resource to the relay device. Upon receiving such control information, the relay device use the UL resource to specifically transmit UL data of the at least one terminal device or UL data of the at least one LCH instead of allocating the UL resource among UL data of all the LCHs and all the terminal devices. Therefore, by allocating the dedicated UL resource in a more fine-grained manner, it is possible to control the granted UL resource for transmission of UL data of specific devices or LCHs.

Some embodiments of the present disclosure will be described in detail below with reference to Fig. 3, which shows a process 300 of resource scheduling. For the purpose of discussion, the process 300 will be described with reference to Fig. 1. The process 300 may involve one or more terminal devices 120, a relay device 110, and an upstream device of the relay device 110 in Fig. 1. The process 300 is related to resource scheduling for UL transmission from the terminal device 120 towards the network device 130. Thus, the upstream device of the relay device 110 may be another relay device 110 or the network device 130. For example, if the process 200 involves the relay device 110-3, the upstream device may be the relay device 110-2. If the process 300 involves the relay device 110-1 (or the relay device 110-2) , its upstream device may be the network device 130.

Similarly as in the process 200, in operation, the relay device 110 may receive 305 UL data of one or more terminal devices 120 to be relayed to the network device 130. The relay device 110 may be directly connected with the one or more terminal devices 120 and then receive the UL data using an access link (s) . Alternatively, the relay device 110 may be directly connected with the one or more relay devices 110 and then receive the UL data relayed by those relay devices 110 using a backhaul link (s) .

The relay device 110 buffers the received UL data of the terminal device (s) 120. The UL data of the terminal device (s) 120 may correspond to on one or more LCHs of the terminal device (s) 120. In the relay device 110, the relay device 110 may also establish a number of LCHs for the UL data. LCHs of the respective terminal device (s) may be mapped to the LCHs of the relay device 110. To transmit the UL data to an upstream device, the relay device 110 may act as a terminal device (i.e., the MT) .

The relay device 110 then transmits 310 for an UL resource for transmission of uplink data of one or more terminal devices 120 to the

upstream device

110 or 130. To request the UL resource, the relay device 110 may, for example, transmit a BRS to indicate a buffer size of UL data buffered at the relay device 110, as described above.

Upon receiving the request from the relay device 110, the

upstream device

110 or 130 determines 315 whether an UL resource is to be dedicated to one or more terminal devices 120 or one or more LCHs of the relay device 110. Depending on the determining, the

upstream device

110 or 130 transmits 320 control information indicating the UL resource to the relay device 110. The UL resource may be indicated in an UL grant in the control information. The control information may be included in DL control information (DCI) from the

upstream device

110 or 130 to the relay device 110.

The control information indicates to the relay device 110 whether the UL resource is dedicated to one or more terminal devices 120 or one or more LCHs of the relay device 110. The one or more terminal devices 120 may be a subset of the terminal devices 120 from which the relay device 110 receives UL data. The one or more LCHs may be a subset of active LCHs of the relay device 110 on which UL data are available for transmission. Without the dedicated UL resource, an UL resource granted by the upstream device may be considered as to the whole relay device 110 (for example, by including a device identification of the relay device 110 in the control information) and the relay device 110 would allocate the UL resource granted by the upstream device among UL data from all the terminal devices on all active LCHs depending on a token bucket algorithm and priorities assigned to the LCHs. However, in embodiments of the present disclosure, the granted UL resource may be dedicated for UL transmission of a certain terminal device or a certain LCH.

Upon receipt of the control information, the relay device 110 determines 325 whether the UL resource is dedicated to at least one terminal device 120 or at least one LCH of the relay device 110. If the UL resource is determined to be dedicated to the at least one terminal device 120, the relay device 110 transmits 330 UL data of the at least one terminal device 120 to the

upstream device

110 or 130 using the dedicated UL resource. If the UL resource is dedicated to the at least one LCH, the relay device 110 transmits 335 UL data corresponding to the at least one LCH to the

upstream device

110 or 130 using the UL resource.

In general, there are three cases for the dedicated UL resources. In a first case, the UL resource is dedicated to one or more terminal devices 120. In a second case, the UL resource is dedicated to one or more individual LCHs of the relay device 110. In a third case, the UL resource is dedicated to one or more LCGs of the relay device 110 consisting of one or more individual LCHs. Some example embodiments related to the three cases will be described in detail below.

In some embodiments of allocating the dedicated UL resource for one or more terminal devices 120, the control information transmitted from the

upstream device

110 or 130 may include device identification of the one or more terminal devices 120. In an embodiment, the UL resource granted via the control information may be dedicated to only one terminal device 120. The DCI carried the control information may be extended to include a field to indicate the device identification. In an embodiment, the device identification may be a UE identity (ID) of a terminal device 120, which may be a Radio Network Temporary Identity (RNTI) allocated to the terminal device 120 by the donor network device 130. The device identification can be used to uniquely identify the terminal device 120, for example, at least among all the terminal devices that are in direct and/or relay communication with the network device 130.

The relay device 110, upon receipt of the control information, may determine whether the control information include a device identification of the one or more terminal devices 120. In the case of detecting the device identification, the relay device 110 may determine that the UL resource is dedicated to the one or more terminal devices 120 and UL data of those terminal devices 120 can be transmitted by the relay device 110 using the allocated UL resource. In this way, it is possible to ensure UL transmission of some certain terminal devices even if the UL data of the terminal devices are mapped to a LCH with a lower priority at the relay device. The relay device 110 may not allocate the dedicated UL resource for transmission of UL data of other terminal devices even if the UL data are on a LCH with a PBR of “infinity. ”

In some embodiments, more priorities may be assigned to LCHs of the relay device 110. In 3GPP communication systems, a terminal device 120 is currently able to establish at most 32 LCHs, each of which may be assigned with one of 16 priorities. The priorities of the LCHs may partially decide whether the LCHs can be allocated with a granted UL resource for transmission. By introducing more priorities for LCHs of the relay device 110, it is possible to achieve one to one or almost one to one bearer mapping at the relay device 110 for the individual bearers of the terminal devices 120. As such, the relay device 110 may distinguish between the terminal devices 120 by distinguishing the bearers of the terminal devices 120 in the backhaul link using different LCH priorities.

Specifically, the relay device 110 may be able to establish a predetermined number of LCHs. One or more of the LCHs of the relay device 110 may be established and active for transmission of UL data. Each of the active LCH s may be assigned with one of a number of predetermined priorities (referred to as a “first number of priorities” sometimes hereinafter for ease of discussion) . The priorities of the LCHs of a relay device 110 may be assigned by the

upstream device

110 or 130 of this relay device. The first number of the priorities available to be assigned to the LCHs of the relay device 110 may be at least greater than the number of predetermined priorities (referred to as “a second number of priorities” sometimes hereinafter for ease of discussion) configurable to LCHs of a terminal device 120. In an embodiment, if the second number of priorities configurable to LCHs of the terminal device 120 is 16, the first number of priorities configurable to LCHs of the relay device 110 is greater than 16, for example, may be a multiple of the second number of priorities configurable to LCHs of the terminal device 120. As some specific examples, the number of priorities configurable to LCHs of the relay device 110 may be set as 32, 64, 128, 256, or the like.

The increasing of the priorities for the LCHs of the relay device 110 may be preconfigured and fixed in the system 100 or may be semi-dynamically configured by the network device 130. For example, a relay device 110 may initially have the same number of priorities for its LCHs as the terminal device 120. The network device 130 may transmit an indication of an increasing factor (greater than one) to the relay device 110 and its

upstream device

110 or 130 to increase the number of the priorities for the LCHs of relay device 110. The indication of such increasing factor may be transmitted in RRC signaling from the network device 130.

In some embodiments, the first number of priorities of LCHs of the relay device 110 may depend on a location of the relay device 110 with respect to the network device 130. The closer the relay device 110 is to the network device 130, the greater the number of priorities of LCHs is. This is because the relay device 110 closer to the network device 130 may be connected directly or indirectly to a larger number of terminal devices 120. For example, if the upstream device is a relay device, the first number of priorities of LCHs of the relay device 110 may be smaller than the number of priorities configurable to LCHs of the upstream relay device 110 (referred to as “a third number of priorities” sometimes hereinafter for ease of discussion) . Similarly, if the relay device 110 is connected to a downstream relay device 110, the number of priorities of LCHs of the relay device 110 may be greater than the number of priorities configurable to LCHs of the downstream relay device 110.

In some embodiments of allocating the dedicated UL resource for one or more LCHs of the relay device 110, the control information transmitted from the

upstream device

110 or 130 may include channel information related to the one or more LCHs. In an embodiment, the UL resource granted via the control information may be dedicated to only one LCH of the relay device 110. In an embodiment, the UL resource may be granted to be dedicated to a LCH that is configured with a PBR greater than PBRs configured to other LCHs of the relay device 110. Considering that the most challenge for LCHs with lower priorities is the LCH with the PBR of “infinity, ” in an example, the UL resource may be granted to be dedicated to the LCH configured with the PBR of “infinity. ” At the side of the relay device 110, upon detecting one of the above channel information in the received control information, the relay device 110 may determine that the UL resource is dedicated to the one or more LCHs and UL data corresponding to the LCHs can be transmitted by the relay device 110 using the allocated UL resource.

To indicate the channel information in the control information, in some embodiments, a dedicated bit is included in the control information to indicate that the UL resource granted in the control information is dedicated to at least one LCH of the relay device 110. In this embodiment, the relay device 110 may be aware of which LCH may potentially be allocated with a dedicated UL resource (such as the LCH with the PBR of “infinity” ) .

In some embodiments, the UL resource dedicated to one or more LCHs of the relay device 110 may be indicated by a dedicated parameter associated with the UL resource, for example, by a dedicated sub-carrier spacing (SCS) associated with the UL resource. In granting an UL resource, the

upstream device

110 or 130 may indicate related parameters for the UL resource. There is a list of available SCSs for UL resources to be granted, examples of which may include 115 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, and/or the like. One of the SCSs may be configured to be dedicated for the one or more LCHs of the relay device 110 in an example. In a further example, more than one SCS may be configured to be dedicated for more than one LCH of the relay device 110 respectively. In an embodiment, the largest SCS (for example, 240 kHz) may be configured to be dedicated to one or more LCHs of the relay device 110. In an embodiment, one or more spare SCSs in the list of available SCSs may be configured to be dedicated to the LCH (s) of the relay device 110. If the upstream device 120 decides to allocate a dedicated UL resource for those LCHs, the UL resource with the dedicated SCS may be scheduled to the relay device 110. As such, the relay device 110 may implicitly determine from the SCS of the UL resource that the UL resource can only be used for transmission of UL data on the specific LCH (s) .

In some embodiments of allocating the dedicated UL resource for one or more LCGs of the relay device 110 consisting of one or more individual LCHs, the control information transmitted from the

upstream device

110 or 130 may include channel information related to the least one LCG to which the LCH (s) of the relay device 110 is assigned.

To indicate the channel information in the control information, in some embodiments, a group identification of the at least one LCG (referred to as “LCG ID” ) may be included in the control information to indicate that the granted UL resource is dedicated to the at least one LCG. The DCI carried the control information may be extended to include a field to indicate the group identification. A LCG ID may uniquely indicate one of the LCGs of the relay device 110. As a specific example, a LCG ID may include a number of bits equal to the number of possible LCGs at the relay device 110, and each of the bits can be valued to indicate whether the UL resource is dedicated to the corresponding LCG. For example, a bit of 1 indicating the UL resource is dedicated to the corresponding LCG while a bit of 0 indicating the opposite case. It would be appreciated that other group identification may be included in the control information to indicate the one or more LCGs.

In some embodiments, the one or more LCGs for the relay device 110 may be indicated by a dedicated parameter associated with the UL resource, for example, by a dedicated sub-carrier spacing (SCS) associated with the UL resource. In granting an UL resource, the

upstream device

110 or 130 may indicate related parameters for the UL resource. There is a list of available SCSs for UL resources to be granted, examples of which may include 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, 480 kHz, 960 kHz, 1920 kHz and/or the like. In an embodiment, if the number of available SCSs is large enough, each of the SCSs may be configured to be corresponding to one of the LCGs for the relay device 110. For example, if there are eight LCGs for the relay device 110, each of the SCSs in the group of 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, 480 kHz, 960 kHz, 1920 kHz may be corresponding to one of the eight LCGs. Upon receipt of the control information, the relay device 110 may implicitly determine from one or more SCSs of the UL resource that the UL resource is allocated to the one or more corresponding LCGs.

In some embodiments, only one or some dedicated SCSs are configured to be corresponding to one or more specific LCGs. The granted UL resource with such dedicated SCSs may indicate that the UL resource can be used for transmission of UL data on LCGs in those specific LCGs only. In some other embodiments, a dedicated bit is included in the control information to indicate that the UL resource granted in the control information is dedicated to at least one LCG for the relay device 110. In this case, the relay device 110 may be aware of which LCGs may potentially be allocated with a dedicated UL resource.

In some embodiments, more LCGs may be introduced for LCHs of a relay device 110. In 3GPP communication systems, the number of LCGs for a terminal device 120 is 8. In the embodiments, it is proposed to introduce more LCGs for LCHs of the relay device 110. By introducing more LCGs at the relay device 110, it is also possible to achieve fine-grained resource scheduling in LCGs. Specifically, it is assumed that the relay device 110 has a predetermined number of LCHs available or active for data transmission. Here, the first number of LCHs include the at least one LCH that is potentially having the dedicated UL resource. The number of available LCHs may be assigned to at least one of the number of predetermined LCGs (referred to as a “first number of LCGs” sometimes hereinafter for ease of discussion) . The assignment of the LCHs to the LCGs may be determined by the

upstream device

110 or 130. Each LCG may be assigned with one or more LCHs.

The first number of LCGs for the relay device 110 may be at least greater than the number of predetermined LCGs (referred to as a “second number of LCGs” sometimes hereinafter for ease of discussion) that are available to be assigned to LCHs of the terminal device 120. In an embodiment, if the second number of LCGs for the terminal device 120 is 8, the first number of LCGs for the relay device 110 is greater than 8, for example, may be a multiple of the second number of LCGs for the terminal device 120. As some specific examples, the first number of LCGs for the relay device 110 may be set as 16, 32, 64, 128, 256, or the like.

In the embodiment of increasing the number of LCGs, the signaling for reporting buffer sizes of the LCGs may be extended. Fig. 4 illustrates an example MAC CE 400 for reporting BSRs for respective LCGs (16 LCGs in this case) . As can be seen, two octets are included to indicate which of the 16 LCGs are available or active for transmission of UL data. In addition, the example MAC CE 400 may include m octets for carrying buffer sizes corresponding to m available LCGs. It would be appreciated that the MAC CE shown in Fig. 4 is merely for purpose of illustration and any other structures for the MAC CE reporting buffer sizes may also be configured.

The increasing of LCGs for the relay device 110 may be preconfigured fixed in the system 100 or may be semi-dynamically configured by the network device 130. For example, a relay device 110 may initially have the same number of LCGs as the terminal device 120. The network device 130 may transmit an indication of an increasing factor (greater than one) to the relay device 110 and its

upstream device

110 or 130 to increase the number of LCGs. The indication of such increasing factor may be transmitted in RRC signaling from the network device 130.

In some embodiments, the first number of LCGs for the relay device 110 may depend on a location of the relay device 110 with respect to the network device 130. The closer the relay device 110 is to the network device 130, the greater the number of LCGs is. This is because the relay device 110 closer to the network device 130 may be connected directly or indirectly to a larger number of terminal devices 120. For example, if the upstream device is a relay device, the first number of LCGs for the relay device 110 may be smaller than the number of LCGs for the upstream relay device 110 (referred to as “a third number of LCGs” sometimes hereinafter for ease of discussion) . Similarly, if the relay device 110 is connected to a downstream relay device 110, the first number of LCGs for the relay device 110 may be greater than the number of LCGs for the downstream relay device 110.

In some embodiments, in assigning the LCHs of the relay device 110 to the LCGs, the

upstream device

110 or 130 may determine whether two or more LCHs are assigned with a same priority and then assign the LCHs with the same priority to a same LCG. Thus, each LCG may have a limited number of priority levels. In some embodiments, the first number of LCGs for the relay device 110 may be equal to the first number of priorities configurable to the LCHs of the relay device 110. As such, there can be a one to one mapping between the LCGs and the priorities. It is thus easy for the

upstream device

110 or 130 to grant resources for the relay device 110. Further, when the dedicated UL resource is allocated to a LCG, the resource may not be drained out by the LCHs with higher priorities in that LCG as all the LCHs therein are at the same level of priority.

In a further solution in accordance of some embodiments of the present disclosure, considering that the most challenge for LCHs with lower priorities is the LCH with the PBR of “infinity, ” it is expected that the PBR of “infinity” is not configured to a LCH of a terminal device accessing a network device via a relay device. In this case, each time the network device assigns the PBR for one or more LCHs of the terminal device, it determines whether the terminal device accesses the network device via one or more relay devices and configures the PBR of the one or more LCHs of the terminal device based on the determining result. As such, it is possible to control the configuration of the LCHs with the PBR of “infinity” in the relay-based communication system.

Some embodiments of the present disclosure will be described in detail below with reference to Fig. 5, which shows a process 500 of resource scheduling. For the purpose of discussion, the process 500 will be described with reference to Fig. 1. The process 500 may involve a terminal device 120 and a network device 130 in Fig. 1. The process 500 is related to assigning PBRs for LCHs of the terminal device 120 by the network device 130. The network device 130 may be a master device of one or more relay devices 110.

In operation, the terminal device 120 may request 505 the network device 130 to configure parameters for one or more LCHs established at the terminal device 120 for UL transmission. The network device 130 determines 510 whether the terminal device 120 accesses the network device 130 via one or more relay devices 110 that are configured to relay UL data towards to the network device 130.

Various approaches can be applied to determine whether a terminal device 120 accesses the network device 130 directly or via one or more relay devices 110. In an embodiment, the terminal device 120 may initiate a random access channel (RACH) procedure to establish a connection with the network device 130. The terminal device 120 may include a request for RRC connection (for example, RRCConnectionrequest signaling) in a message during the RACH procedure (such as MSG3) and then a DU of a relay device 110 may forward the message to a control unit (CU) of the network device 130. In this case, the network device 130 may be aware of the terminal device 120 connecting to the network device 130 via the relay device 110. In some embodiments, when a relay device 110 initially accesses the network device 130, although the MT part of the relay device 110 works like a terminal device but a backhaul link is established. The configurations of the MT and DU parts of the network device may be different. Thus, the network device 130 may distinguish the relay devices 110 and the actual terminal device 120 accordingly. It would be appreciated that the network device 130 may identify whether a terminal device 120 accesses the network device 130 via one or more relay device using any other approaches.

Depending on the determining result, the network device 130 configures 515 a PBR to an available LCH of the terminal device 120. If more than one LCH of the terminal device 120 is available, the network device 130 may configure their PBRs accordingly. Specifically, if the terminal device 120 is determined to access the network device 130 via one or more relay devices 110, the network device 130 may configure the PBR (s) of the LCH (s) of the terminal device 120 to a value lower than a PBR threshold. In an embodiment, the network device 130 may prevent the PBR (s) of the LCH (s) of the terminal device 120 from being configured to “infinity. ” As such, it is possible to avoid the UL resource granted by an upstream device to a relay device or a terminal device from being drained out by the LCH with the PBR of “infinity. ”

In some embodiments, if the relay device 110 detects the PBR of a LCH of the terminal device is set to “infinity, ” the relay device 110 may consider the PBR of the LCH as a limited PBR, such as the highest PBR other than “infinity” (for example, 65536 kBps in some communication systems) .

Fig. 6 shows a flowchart of an example method 600 in accordance with an embodiment of the present disclosure. The method 600 can be implemented at a relay device 110 as shown in Fig. 1.

At block 610, the relay device 110 determines a target buffer size of uplink data of at least one terminal device that is buffered at the relay device. At block 620, the relay device 110 determines, from a first mapping between a first set of buffer sizes and a first set of indices, at least one index to indicate a buffer size equal to or smaller than the target buffer size by comparing the target buffer size and a first upper limit of buffer size that is allowable be reported to an upstream device, the first upper limit of buffer size being greater than a second upper limit of buffer size configured for the at least one terminal device. At block 630, the relay device 110 transmits the at least one determined index to the upstream device to request an uplink resource for transmission of the buffered uplink data to the upstream device.

In some embodiments, determining the at least one index comprises in response to the target buffer size being within the first upper limit of buffer size, determining at least one index to indicate the target buffer size; and in response to the target buffer size exceeding the first upper limit of buffer size, determining at least one index to indicate the first upper limit of buffer size.

In some embodiments, the method 600 further comprises receiving, from a master device of the relay device, configuration information for configuring the first mapping to the relay device.

In some embodiments, the relay device has been configured with a second mapping between a second set of buffer sizes and a second set of indices. The method 600 further comprises receiving a first indication of a first enlargement factor from a master device of the relay device, the enlargement factor being greater than one; and determining the first mapping by multiplying the second set of buffer sizes in the second mapping by the first enlargement factor.

In some embodiments, determining the at least one index comprises receiving, from a master device of the relay device, an enabling indication that the first mapping is enabled; and in response to receipt of the enabling indication, determining the at least one index from the first mapping.

In some embodiments, the relay device is connected to a downstream relay device. The method 600 further comprises receiving, from a master device of the relay device, a second indication of a second enlargement factor for the downstream relay device, the second enlargement factor being used by the downstream relay device to determine a third mapping between a third set of buffer sizes and a third set of indices.

In some embodiments, determining the at least one index comprises: comparing the target buffer size with a maximum buffer size of the buffer sizes in the first mapping; and in response to the target buffer size exceeding the maximum buffer size, selecting at least two of the indices in the first mapping, a sum of at least two buffer sizes mapped to the at least two selected indices being equal to or smaller than the target buffer size.

In some embodiments, transmitting the at least one index comprises: transmitting a control element to carry the at least two indices; or transmitting at least two control elements to carry the at least two indices, respectively.

In some embodiments, the first upper limit of buffer size is greater than a third upper limit of buffer size configured for a downstream relay device from which the uplink data is received.

In some embodiments, the relay device comprises an integrated access backhaul (IAB) node.

Fig. 7 shows a flowchart of an example method 700 in accordance with an embodiment of the present disclosure. The method 700 can be implemented at a relay device 110 as shown in Fig. 1.

At block 710, the relay device 110 receives, from an upstream device, control information indicating an uplink resource allocated to the relay device. At block 720, the relay device 110 determines whether the uplink resource is dedicated to at least one terminal device or at least one logical channel of the relay device. In response to determining that the uplink resource is dedicated to the at least one terminal device, at block 730, the relay device 110 transmits uplink data of the at least one terminal device to the upstream device using the uplink resource. In response to determining that the uplink resource is dedicated to the at least one logical channel, at block 740, the relay device 110 transmits uplink data corresponding to the at least one logical channel to the upstream device using the uplink resource.

In some embodiments, the determining comprises: determining whether the control information comprises a device identification of the at least one terminal device; and in response to determining that the control information comprises the device identification, determining that the uplink resource is dedicated to the at least one terminal device.

In some embodiments, the determining comprises: determining whether the control information comprises channel information related to the at least one logical channel; and determining, based on the channel information, that the uplink resource is dedicated to the at least one logical channel.

In some embodiments, the channel information comprises one of the following: a bit to indicate that the uplink resource is dedicated to the at least one logical channel, a configuration of a sub-carrier spacing (SCS) associated with the uplink resource, the sub-carrier spacing being dedicated to the at least one logical channel or to a logical channel group to which the at least one channel is mapped, or a group identification of at least one logical channel group to which the at least one logical channel is assigned.

In some embodiments, the at least one logical channel comprises a logical channel that is configured with a prioritized bit rate (PBR) of infinity.

In some embodiments, PBRs of logical channels of the at least one terminal device are expected by the relay device to be prevented from being configured to infinity.

In some embodiments, the relay device has a predetermined number of logical channels available for data transmission, the predetermined number of logical channels being assigned with respective priorities selected from a first number of priorities, the first number of priorities being greater than a second number of priorities configurable to logical channels of the at least one terminal device.

In some embodiments, the upstream device is a further relay device, and the first number of priorities is smaller than a third number of priorities configurable to logical channels of the upstream device.

In some embodiments, the relay device has a predetermined number of logical channels available for data transmission, the predetermined number of logical channels comprising the at least one logical channel, and wherein the predetermined number of logical channels are assigned to at least one of a first number of logical channel groups that are available for the relay device, the first number of logical channel groups being greater than a second number of logical channel groups that are available for the at least one terminal device.

In some embodiments, the upstream device is a further relay device, and the fifth number is smaller than a seventh number of predetermined logical channel groups that are available to be assigned to logical channels of the upstream device.

In some embodiments, each of the at least one logical channel group is assigned with a plurality of logical channels that are configured with a same priority.

Fig. 8 shows a flowchart of an example method 800 in accordance with an embodiment of the present disclosure. The method 800 can be implemented at an upstream device of a relay device 110 as shown in Fig. 1. The upstream device may be a relay device 110 or a network device 130.

At block 810, the upstream device receives, from the relay device, a request for an uplink resource for transmission of uplink data of at least one terminal device. At block 820, in response to the request, the upstream device determines whether an uplink resource is to be dedicated to the at least one terminal device or at least one logical channel of the relay device. At block 830, the upstream device transmits, based on the determining, control information indicating the uplink resource to the relay device.

In some embodiments, the transmitting comprises: in response to determining that the uplink resource is to be dedicated to the at least one terminal device, transmitting the control information comprising a device identification of the at least one terminal device to indicate that the uplink resource is to be dedicated to the at least one terminal device.

In some embodiments, the determining comprises: in response to determining that the uplink resource is to be dedicated to the at least one logical channel of the relay device, transmitting the control information comprising channel information related to the at least one logical channel to indicate that the uplink resource is to be dedicated to the at least one logical channel.

In some embodiments, the channel information comprises one of the following: a dedicated bit to indicate that the uplink resource is dedicated to the at least one logical channel, a configuration of a sub-carrier spacing (SCS) associated with the uplink resource, the sub-carrier spacing being dedicated to the at least one logical channel or to a logical channel group to which the at least one channel is mapped, or a group identification of at least one logical channel group to which the at least one logical channel is assigned.

In some embodiments, the relay device comprises an integrated access backhaul (IAB) node, and wherein the upstream device comprises a further IAB node or a master device of the relay device.

Fig. 9 shows a flowchart of an example method 900 in accordance with an embodiment of the present disclosure. The method 900 can be implemented at a master device of a relay device 110 as shown in Fig. 1, such as the network device 130.

At block 910, the network device 130 determines, at a master device of a relay device, whether a terminal device accesses the master device via the relay device, the relay device being configured to transmit uplink data of the terminal device towards the master device. At block 920, the network device 130 configures, based on the determining, a prioritized bit rate (PBR) to a logical channel of the terminal device that is available for data transmission.

In some embodiments, configuring the PBR to the logical channel comprises: in response to determining that the terminal device accesses the master device via the relay device, configuring the PBR to be a value lower than a PBR threshold.

In some embodiments, configuring the PBR to the logical channel comprises: in response to determining that the terminal device accesses the master device via the relay device, preventing the PBR from being configured to infinity.

Fig. 10 is a simplified block diagram of a device 1000 that is suitable for implementing embodiments of the present disclosure. The device 1000 can be considered as a further example implementation of the relay device 110, the terminal device 120, or the network device 130 as shown in Fig. 1. Accordingly, the device 1000 can be implemented at or as at least a part of the relay device 110, the terminal device 120, or the network device 130.

As shown, the device 1000 includes a processor 1010, a memory 1020 coupled to the processor 1010, a suitable transmitter (TX) and receiver (RX) 1040 coupled to the processor 1010, and a communication interface coupled to the TX/RX 1040. The memory 1020 stores at least a part of a program 1030. The TX/RX 1040 is for bidirectional communications. The TX/RX 1040 has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones. The communication interface may represent any interface that is necessary for communication with other network elements, such as X2 interface for bidirectional communications between eNBs, S1 interface for communication between a Mobility Management Entity (MME) /Serving Gateway (S-GW) and the eNB, Un interface for communication between the eNB and a relay node (RN) , or Uu interface for communication between the eNB and a terminal device.

The program 1030 is assumed to include program instructions that, when executed by the associated processor 1010, enable the device 1000 to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to Figs. 2 to 10. The embodiments herein may be implemented by computer software executable by the processor 1010 of the device 1000, or by hardware, or by a combination of software and hardware. The processor 1010 may be configured to implement various embodiments of the present disclosure. Furthermore, a combination of the processor 1010 and memory 1020 may form processing means 1050 adapted to implement various embodiments of the present disclosure.

The memory 1020 may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory 1020 is shown in the device 1000, there may be several physically distinct memory modules in the device 1000. The processor 1010 may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1000 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representation, it will be appreciated that the blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the process or method as described above with reference to any of Figs. 2 to 10 Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

The above program code may be embodied on a machine readable medium, which may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A method for communication comprising:

determining, at a relay device, a target buffer size of uplink data of at least one terminal device that is buffered at the relay device;

determining, from a first mapping between a first set of buffer sizes and a first set of indices, at least one index to indicate a buffer size equal to or smaller than the target buffer size by comparing the target buffer size and a first upper limit of buffer size that is allowable be reported to an upstream device, the first upper limit of buffer size being greater than a second upper limit of buffer size configured for the at least one terminal device; and

transmitting the at least one determined index to the upstream device to request an uplink resource for transmission of the buffered uplink data to the upstream device.
The method of claim 1, wherein determining the at least one index comprises:

in response to the target buffer size being within the first upper limit of buffer size, determining at least one index to indicate the target buffer size; and

in response to the target buffer size exceeding the first upper limit of buffer size, determining at least one index to indicate the first upper limit of buffer size.
The method of claim 1, further comprising:

receiving, from a master device of the relay device, configuration information for configuring the first mapping to the relay device.
The method of claim 3, wherein the relay device has been configured with a second mapping between a second set of buffer sizes and a second set of indices, the method further comprising:

receiving a first indication of a first enlargement factor from a master device of the relay device, the enlargement factor being greater than one; and

determining the first mapping by multiplying the second set of buffer sizes in the second mapping by the first enlargement factor.
The method of claim 1, wherein determining the at least one index comprises:

receiving, from a master device of the relay device, an enabling indication that the first mapping is enabled; and

in response to receipt of the enabling indication, determining the at least one index from the first mapping.
The method of claim 1, wherein the relay device is connected to a downstream relay device, the method further comprising:

receiving, from a master device of the relay device, a second indication of a second enlargement factor for the downstream relay device, the second enlargement factor being used by the downstream relay device to determine a third mapping between a third set of buffer sizes and a third set of indices.
The method of claim 1, wherein determining the at least one index comprises:

comparing the target buffer size with a maximum buffer size of the buffer sizes in the first mapping; and

in response to the target buffer size exceeding the maximum buffer size, selecting at least two of the indices in the first mapping, a sum of at least two buffer sizes mapped to the at least two selected indices being equal to or smaller than the target buffer size.
The method of claim 7, wherein transmitting the at least one index comprises:

transmitting a control element to carry the at least two indices; or

transmitting at least two control elements to carry the at least two indices, respectively.
The method of claim 1, wherein the first upper limit of buffer size is greater than a third upper limit of buffer size configured for a downstream relay device from which the uplink data is received.
The method of claim 1, wherein the relay device comprises an integrated access backhaul (IAB) node.
A method for communication comprising:

receiving, at a relay device and from an upstream device, control information indicating an uplink resource allocated to the relay device;

determining whether the uplink resource is dedicated to at least one terminal device or at least one logical channel of the relay device;

in response to determining that the uplink resource is dedicated to the at least one terminal device, transmitting uplink data of the at least one terminal device to the upstream device using the uplink resource; and

in response to determining that the uplink resource is dedicated to the at least one logical channel, transmitting uplink data corresponding to the at least one logical channel to the upstream device using the uplink resource.
The method of claim 11, wherein the determining comprises:

determining whether the control information comprises a device identification of the at least one terminal device; and

in response to determining that the control information comprises the device identification, determining that the uplink resource is dedicated to the at least one terminal device.
The method of claim 11, wherein the determining comprises:

determining whether the control information comprises channel information related to the at least one logical channel; and

determining, based on the channel information, that the uplink resource is dedicated to the at least one logical channel.
The method of claim 13, wherein the channel information comprises one of the following:

a bit to indicate that the uplink resource is dedicated to the at least one logical channel,

a configuration of a sub-carrier spacing (SCS) associated with the uplink resource, the sub-carrier spacing being dedicated to the at least one logical channel or to a logical channel group to which the at least one channel is mapped, or

a group identification of at least one logical channel group to which the at least one logical channel is assigned.
The method of claim 14, wherein the at least one logical channel comprises a logical channel that is configured with a prioritized bit rate (PBR) of infinity.
The method of claim 11, wherein PBRs of logical channels of the at least one terminal device are expected by the relay device to be prevented from being configured to infinity.
The method of claim 11, wherein the relay device has a predetermined number of logical channels available for data transmission, the predetermined number of logical channels being assigned with respective priorities selected from a first number of priorities, the first number of priorities being greater than a second number of priorities configurable to logical channels of the at least one terminal device.
The method of claim 17, wherein the upstream device is a further relay device, and the first number of priorities is smaller than a third number of priorities configurable to logical channels of the upstream device.
The method of claim 11, wherein the relay device has a predetermined number of logical channels available for data transmission, the predetermined number of logical channels comprising the at least one logical channel, and wherein the predetermined number of logical channels are assigned to at least one of a first number of logical channel groups that are available for the relay device, the first number of logical channel groups being greater than a second number of logical channel groups that are available for the at least one terminal device.
The method of claim 19, wherein the upstream device is a further relay device, and the fifth number is smaller than a seventh number of predetermined logical channel groups that are available to be assigned to logical channels of the upstream device.
The method of claim 19, wherein each of the at least one logical channel group is assigned with a plurality of logical channels that are configured with a same priority.
The method of claim 11, wherein the relay device comprises an integrated access backhaul (IAB) node.
A method for communication comprising:

receiving, at an upstream device of a relay device and from the relay device, a request for an uplink resource for transmission of uplink data of at least one terminal device;

in response to the request, determining whether an uplink resource is to be dedicated to the at least one terminal device or at least one logical channel of the relay device; and

transmitting, based on the determining, control information indicating the uplink resource to the relay device.
The method of claim 23, wherein the transmitting comprises:

in response to determining that the uplink resource is to be dedicated to the at least one terminal device, transmitting the control information comprising a device identification of the at least one terminal device to indicate that the uplink resource is to be dedicated to the at least one terminal device.
The method of claim 23, wherein the determining comprises:

in response to determining that the uplink resource is to be dedicated to the at least one logical channel of the relay device, transmitting the control information comprising channel information related to the at least one logical channel to indicate that the uplink resource is to be dedicated to the at least one logical channel.
The method of claim 25, wherein the channel information comprises one of the following:

a dedicated bit to indicate that the uplink resource is dedicated to the at least one logical channel,

a configuration of a sub-carrier spacing (SCS) associated with the uplink resource, the sub-carrier spacing being dedicated to the at least one logical channel or to a logical channel group to which the at least one channel is mapped, or

a group identification of at least one logical channel group to which the at least one logical channel is assigned.
The method of claim 23, wherein the relay device comprises an integrated access backhaul (IAB) node, and wherein the upstream device comprises a further IAB node or a master device of the relay device.
A method for communication comprising:

determining, at a master device of a relay device, whether a terminal device accesses the master device via the relay device, the relay device being configured to transmit uplink data of the terminal device towards the master device; and

configuring, based on the determining, a prioritized bit rate (PBR) to a logical channel of the terminal device that is available for data transmission.
The method of claim 28, wherein configuring the PBR to the logical channel comprises:

in response to determining that the terminal device accesses the master device via the relay device, configuring the PBR to be a value lower than a PBR threshold.
The method of claim 28, wherein configuring the PBR to the logical channel comprises:

in response to determining that the terminal device accesses the master device via the relay device, preventing the PBR from being configured to infinity.
A relay device, comprising:

a processing unit; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to any of claims 1-10.
A relay device, comprising:

a processing unit; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to any of claims 11-22.
A communication device, the device being an upstream device of a relay device and comprising:

a processing unit; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to any of claims 23-27.
A master device, comprising:

a processing unit; and

a memory coupled to the processing unit and storing instructions thereon, the instructions, when executed by the processing unit, causing the device to perform the method according to any of claims 28-30.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 1-10.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 11-22.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 23-27.
A computer readable medium having instructions stored thereon, the instructions, when executed on at least one processor, causing the at least one processor to carry out the method according to any of claims 28-30.