US-12628153-B2 - Enhanced scheduling in wireless networks with relay function

US12628153B2US 12628153 B2US12628153 B2US 12628153B2US-12628153-B2

Abstract

Enhanced scheduling in wireless networks with relay function In cellular or other wireless networks, relay terminal devices can be introduced to support an indirect network connection for remote terminal devices in out-of-coverage (OoC) areas to thereby improve network coverage. Such relay terminal devices buffer upstream and downstream data from/to other terminal devices that are indirectly connected. However, a relay terminal device may have a limited memory allocation for buffering. This limitation has a high impact on the optimal resource scheduling performed by network access devices. It is therefore proposed to have relay terminal devices report information about their available or maximum buffer capacity to their respective network access devices to enable optimal resource scheduling by the access devices.

Inventors

Walter Dees
Esko Olavi Dijk

Assignees

KONINKLIJKE PHILIPS N.V.

Dates

Publication Date: 20260512
Application Date: 20210421
Priority Date: 20200422

Claims (16)

1 . An apparatus for scheduling communication resources of at least one communication device in a wireless network, wherein the apparatus comprises: a capacity detector configured to detect a buffer capacity information signaled from the wireless network and indicating available or maximum buffer capacity of at least one relay communication device; and a scheduler configured to schedule communication resources for at least one of a transmission of upstream or downstream data for a target communication device over a device-to-device communication channel between the target communication device and the at least one relay communication device, and a transmission of upstream or downstream data for the at least one relay communication device over a device-to-device communication channel between the at least one relay communication device and another relay communication device or over a direct radio access link between the at least one relay communication device and an access device, based on the received buffer capacity information, wherein the scheduler is configured to decide based on the received buffer capacity information to add and/or remove at least one parent relay communication device for one of a relay or remote communication device in the wireless network.
2 . The apparatus of claim 1 , wherein the scheduler is configured to perform buffer capacity control by at least one of commanding a relay communication device to increase or decrease a buffer capacity for a specific logical channel or logical channel group, or a specific downstream relay or remote communication device, switching the relay communication device between an autonomous mode of buffer allocation and a directed mode of buffer allocation, setting a buffer allocation policy at the relay communication device, setting a reporting granularity of the relay communication device, and commanding the relay communication device to merge multiple separate buffers into one buffer allocation.
3 . An access device for a wireless network, comprising an apparatus according to claim 1 .
4 . An apparatus for controlling scheduling of communication resources of at least one communication device in a wireless network, wherein the apparatus comprises: a capacity detector configured to determine an available or maximum buffer capacity of a data buffer at a relay communication device; and a capacity reporter for reporting a buffer capacity information including the determined available or maximum buffer capacity to the wireless network in response to a trigger event, wherein the capacity reporter is configured to send the buffer capacity information to a network function, the buffer capacity information being forwarded to a scheduling access device of the wireless network, and wherein the scheduling access device includes a scheduler configured to decide based on the received buffer capacity information to add and/or remove at least one parent relay communication device for one of a relay or remote communication device in the wireless network.
5 . The apparatus of claim 4 , wherein the capacity reporter is configured to report the buffer capacity information in an absolute format or in a relative format.
6 . The apparatus of claim 4 , wherein the capacity reporter is configured to report the buffer capacity information for at least one of different logical channels present for at least one upstream link and/or at least one downstream link of a relay communication device, different priority classes of buffered data present in the relay communication device, and different downstream communication devices (present for the relay communication device, or to combine buffer capacity reports of one or more downstream communication devices with an own buffer capacity report.
7 . The apparatus of claim 6 , wherein the capacity reporter is configured to report a binary payload in which a plurality of elements are concatenated, each element corresponding to a buffer capacity report of one logical channel of the relay communication device or to include the own buffer capacity report and/or a buffer capacity report of a side-link connected communication device into a combined buffer capacity report, or to summarize buffer capacity information into a more condensed buffer capacity report, or to report pairs of logical channels or logical channel groups and related buffer capacity reports, or to report pairs of data priority classes and related buffer capacity reports, or to select more relevant or urgent buffer capacity reports for prioritized reporting, or to combine at least one buffer capacity report and at least one buffer size report into one report.
8 . The apparatus of claim 4 , wherein the capacity reporter is configured to include in a buffer capacity report information related to, or encode a buffer capacity report by using at least one of a buffer capacity index for a look-up table, a buffer load percentage, a mapping of reported buffer capacity to capacity categories, a flag indicating whether a buffer capacity threshold has been reached or exceeded, a compound value indicating a resource usage of the relay communication device where said value is at least partly determined by its current or a past buffer capacity, a compound value indicating a preference or ability of the relay communication device for accepting an additional remote communication device where said value is at least partly determined by its current or a past buffer capacity, including meta information about a buffer, and including specific requests triggered by buffer-related conditions.
9 . The apparatus of claim 4 , wherein the capacity reporter is configured to include in a buffer capacity report information related to, or encode a buffer capacity report, at least one of an index for a buffer load look-up table, a current buffer load percentage, a past buffer load, a mapping of reported buffer load to load categories, a flag indicating whether a buffer load threshold has been reached or exceeded, a compound value indicating a resource usage of the relay communication device where said value is at least partly determined by its current or a past buffer load, or a compound value indicating a preference or ability of the relay communication device for accepting an additional remote communication device where said value is at least partly determined by its current or a past buffer load.
10 . The apparatus of claim 4 , wherein the capacity reporter is configured to report the buffer capacity information by using at least one of or a combination of a transport protocol on top of the Internet Protocol, a message of a radio resource control protocol, a packet data unit of a packet data convergence protocol, a control element of a media access control protocol, a service data unit of a media access control protocol, and a data format of an uplink control information or a sidelink control information.
11 . The apparatus of claim 4 , wherein the trigger event corresponds to at least one of a change of a maximum buffer capacity on a relay communication device to a lower capacity, a change of an available buffer capacity of a data buffer, a timer-based trigger, an increase of a load of a data buffer by a predetermined percentage, fraction or data size with respect to a previous reported buffer capacity information, a receipt of a buffer capacity query from a scheduling access device or an upstream relay communication device, a change of a buffer capacity on a remote communication device, a receipt of a buffer size or capacity report from a downstream remote or relay communication device, a receipt of a buffer status message or scheduling request message from a downstream remote or relay communication device, a receipt of a communication resource request message from a downstream or relay communication device, a receipt of a discovery or status request message from a downstream device or out-of-coverage communication device, a receipt of a request from an access device, and a receipt of a recommended bit rate message or recommended bit rate query message from a downstream remote or relay communication device.
12 . A relay communication device for a wireless network, comprising an apparatus according to claim 4 .
13 . A method of scheduling communication resources of at least one communication device in a wireless network, wherein the method comprises: detecting buffer capacity information signaled from the wireless network and indicating available buffer capacity of at least one relay communication device; scheduling at least one of a transmission of upstream or downstream data for a target communication device over a device-to-device communication channel between the target communication device and the at least one relay communication device, and a transmission of upstream or downstream data for the at least one relay communication device over a device-to-device communication channel between the at least one relay communication device and another relay communication device or over a direct radio access link between the at least one relay communication device and an access device, based on the detected buffer capacity information; and deciding based on the received buffer capacity information to add and/or remove at least one parent relay communication device for one of a relay or remote communication device in the wireless network.
14 . A non-transitory computer program product comprising code means for producing the steps of claim 13 when run on a computer device.
15 . A method of controlling scheduling of communication resources of at least one communication device in a wireless network, wherein the method comprises: determining an available or maximum buffer capacity of a data buffer at a relay communication device; reporting the determined available or maximum buffer capacity to the wireless network in response to a trigger event; sending the buffer capacity information to a network function, the buffer capacity information being forwarded to a scheduling access device of the wireless network; and deciding based on the received buffer capacity information to add and/or remove at least one parent relay communication device for one of a relay or remote communication device in the wireless network.
16 . A non-transitory computer program product comprising code means for producing the steps of claim 15 when run on a computer device.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a U.S. national phase application of International Application No. PCT/EP2021/060299 filed on Apr. 21, 2021, which claims the benefit of EP Application Serial No. 20170956.5 filed on Apr. 22, 2020 and EP Application Serial No. 21166763.9 filed Apr. 1, 2021 and are incorporated herein by reference. FIELD OF THE INVENTION The invention relates to resource scheduling in wireless networks with relay function, such as—but not limited to—cellular networks with indirect network connections for remote communication devices (e.g. terminal devices such as user equipments (UEs)) which are out of network coverage. BACKGROUND OF THE INVENTION Many wireless communication systems use network access devices (such as base stations, Node Bs (eNBs, eNodeBs, gNBs, gNodeBs, ng-eNBs, etc.), access points or the like) to provide geographical service areas where wireless communication devices (e.g. terminal devices such as mobile stations or UEs) communicate with an access device serving a particular geographical service area in which the terminal devices are located. The access devices are connected within a network allowing communication links to be made between the wireless communication devices and other devices. In some circumstances, the communication links are between wireless communication devices that are close to each other. In these situations, it may be desirable to have a direct communication link between two wireless communication devices rather than communicating through an access device. Such direct communication between communication devices is often referred to as device-to-device (D2D) communication or peer-to-peer (P2P) communication. The communication resources (e.g., time-frequency blocks) used for D2D or P2P communication can be a subset of the communication resources used by the communication system for communication between wireless communication devices and access devices or they can be a different set of communication resources (e.g. unlicensed band or millimeter wave band). An in-coverage (InC) communication device is a communication device that is within the service area of an access device and is capable of communication with the access device. An out-of-coverage (OoC) device or remote communication device is typically a communication device that is not within a service area of any access device or that is in the service area of an access device but the access device does not allow access (e.g. because it is a non-public network (NPN) access device). Service requirements related to wireless communication systems consider D2D in different ways. A first approach is to use direct device connection without any network entity in the middle. A second approach is to provide a relay communication device between two remote devices. A third approach is to provide a relay communication device between a remote communication device and the network. This is called indirect network connection mode. The relay communication device may use multiple access schemes such as 5G New Radio (NR) radio access technology, Long Term Evolution (LTE), WiFi, or fixed broadband. Radio frequency resources are considered an expensive utility whose management has been of a great challenge for the evolution of cellular networks. On top of that, data traffic with strict latency and reliability requirements in upcoming cellular networks requires an efficient resource allocation scheme to make it a success. In a radio access network (RAN), access devices should schedule communication resources for transmission for all communication devices to obtain maximum efficiency of spectrum resource usage. In a RAN that supports indirect network connections, this includes scheduling for any indirectly connected remote or relay communication device. Therefore, scheduling should be extended to work for directly and indirectly connected communication devices, including those communication devices that are indirectly connected via two or more relay communication devices (“multi-hop”). In addition, scheduling solutions should take into account that a relay communication device may have limited buffer memory space available to buffer data for relayed data flows. The access device should therefore perform scheduling in a manner such that buffer overflows and resultant data loss do not occur. Moreover, scheduling solutions should take into account that buffer memory available at a relay communication device to buffer data for a specific upstream parent or downstream child communication device may vary per device type (e.g. low-cost Internet of Things (IoT) node versus powerful mobile phone) and over time (e.g. if a relay communication device has only one child remote communication device at a given time, it may have far more buffer memory available for that child device than if it has fifteen downstream communication devices assigned to it). SUMMARY OF THE INVENTION It is an object of the present in