U.S. patent application number 16/700683 was filed with the patent office on 2020-04-30 for devices and methods for cloud-based sidelink scheduling and base station interface therefor.
The applicant listed for this patent is Huawei Technologies Co., Ltd.. Invention is credited to Serkan AYAZ, Prajwal KESHAVAMURTHY, Daniel MEDINA, Chan ZHOU.
Application Number | 20200137814 16/700683 |
Document ID | / |
Family ID | 59227691 |
Filed Date | 2020-04-30 |
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United States Patent
Application |
20200137814 |
Kind Code |
A1 |
AYAZ; Serkan ; et
al. |
April 30, 2020 |
DEVICES AND METHODS FOR CLOUD-BASED SIDELINK SCHEDULING AND BASE
STATION INTERFACE THEREFOR
Abstract
The present invention relates to a network entity (110), in
particular a cloud server (110), comprising a processor (110a)
being configured to control radio resources, in particular sidelink
radio resources, on behalf of one or more, in particular two,
mobile networks (PLMNs) (120, 130). Moreover, the invention relates
to a base station (BS) (123, 133) of a PLMN (120, 130), comprising
a processor (133a) configured to process control plane information
related to control of radio resources, in particular sidelink radio
resources, and a communication interface (133b) configured to
transmit and/or receive to/from the network entity (110) said
control plane information.
Inventors: |
AYAZ; Serkan; (Munich,
DE) ; MEDINA; Daniel; (Munich, DE) ;
KESHAVAMURTHY; Prajwal; (Munich, DE) ; ZHOU;
Chan; (Munich, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Huawei Technologies Co., Ltd. |
Shenzhen |
|
CN |
|
|
Family ID: |
59227691 |
Appl. No.: |
16/700683 |
Filed: |
December 2, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2017/082688 |
Dec 13, 2017 |
|
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16700683 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 76/27 20180201;
H04W 92/18 20130101; H04W 88/04 20130101; H04W 72/02 20130101; H04L
2212/00 20130101; H04W 76/00 20130101; H04W 84/042 20130101; H04W
8/005 20130101; H04W 72/1278 20130101; H04W 76/14 20180201; H04W
4/40 20180201; H04W 72/1205 20130101 |
International
Class: |
H04W 76/14 20060101
H04W076/14; H04W 88/04 20060101 H04W088/04; H04W 72/02 20060101
H04W072/02; H04W 8/00 20060101 H04W008/00; H04W 76/27 20060101
H04W076/27; H04W 72/12 20060101 H04W072/12 |
Foreign Application Data
Date |
Code |
Application Number |
May 30, 2017 |
EP |
PCT/EP2017/063050 |
Claims
1. A network entity, in particular a cloud server, comprising a
processor being configured to control radio resources, in
particular sidelink radio resources, on behalf of one or more, in
particular two, mobile networks (PLMNs).
2. The network entity of claim 1, wherein the processor is
configured to control sidelink radio resources for transmission by
at least one of a first user equipment (UE) of a first PLMN and a
second UE of a second PLMN.
3. The network entity of claim 1, wherein the processor is
configured to at least one of: perform at least one of dynamic and
semi-persistent scheduling of sidelink transmissions by allocating
one or more sidelink radio resources to at least one of a first UE
of the first PLMN and a second UE of the second PLMN; and set the
value of one or more sidelink radio interface configuration
parameters for at least one of the first UE of the first PLMN and
the second UE of the second PLMN.
4. The network entity of claim 1, wherein the radio resources are
located on a same carrier.
5. The network entity of claim 1, comprising a communication
interface for communication with at least one of a first base
station (BS) of the first PLMN and a second BS of the second
PLMN.
6. The network entity according to claim 1, wherein the
communication interface is configured to at least one of: transmit
scheduling information to the first BS, wherein the scheduling
information specifies one or more sidelink radio resources
allocated to the first UE for transmission of at least one of
sidelink control information and sidelink user data; and transmit
scheduling information to the second BS, wherein the scheduling
information specifies one or more sidelink radio resources
allocated to the second UE for transmission of at least one of
sidelink control information and sidelink user data.
7. The network entity of claim 1, wherein the scheduling
information comprises one or more of the following: a carrier
indicator; a location of the one or more sidelink radio resources
in the time domain; a location of the one or more sidelink radio
resources in the frequency domain; a retransmission related
parameter; a semi-persistent scheduling (SPS) related
parameter.
8. The network entity of claim 5, wherein the communication
interface is configured to at least one of: transmit the one or
more sidelink radio interface configuration parameters for the
first UE to the first BS; and transmit the one or more sidelink
radio interface configuration parameters for the second UE to the
second BS.
9. The network entity of claim 1, wherein the one or more sidelink
radio interface configuration parameters comprise one or more radio
resource control (RRC) parameters controlling the operation of at
least one of the medium access control (MAC) layer and the physical
(PHY) layer for sidelink communication.
10. The network entity of claim 9, wherein the one or more radio
resource control (RRC) parameters controlling the operation of at
least one of the medium access control (MAC) layer and the physical
(PHY) layer for sidelink communication comprise one or more of the
following: a radio resource pool configuration parameter; a zone
configuration parameter; a radio resource selection configuration
parameter; a semi-persistent scheduling (SPS) configuration
parameter; a measurement configuration parameter.
11. The network entity of claim 5, wherein the communication
interface is further configured to receive from at least one of the
first BS and the second BS at least one of one or more sidelink
radio resource request parameters and one or more measurements.
12. The network entity of claim 1, wherein the one or more sidelink
radio resource request parameters comprise one or more of the
following: a carrier frequency for at least one of transmitting and
receiving by a UE; a destination ID; a parameter for
semi-persistent scheduling (SPS), in particular periodicity, timing
offset, at least one of priority and message size; and/or wherein
the one or more measurements comprise one or more of the following:
a geographic location of a UE; a received signal strength in one or
more radio resources; a sidelink buffer status.
13. A base station (BS) of a PLMN, comprising a processor
configured to process control plane information related to control
of radio resources, in particular sidelink radio resources, and a
communication interface configured to at least one of transmit and
receive to/from a network entity, in particular a cloud server,
said control plane information.
14. The base station of claim 13, wherein the communication
interface is configured to transmit to the network entity at least
one of one or more sidelink radio resource request parameters and
one or more measurements.
15. The base station of claim 13, wherein the one or more sidelink
radio resource request parameters comprise one or more of the
following: a carrier frequency for at least one of transmitting and
receiving by a UE; a destination ID; a parameter for
semi-persistent scheduling, in particular periodicity, timing
offset, at least one of priority and message size; and/or wherein
the one or more measurements comprise one or more of the following:
a geographic location of a UE; a received signal strength in one or
more radio resources; a sidelink buffer status.
16. The base station of claim 13, wherein the communication
interface is configured to receive from the network entity
scheduling information, wherein the scheduling information
specifies one or more sidelink radio resources allocated to a UE
for transmission of at least one of sidelink control information
and sidelink user data.
17. The base station of claim 13, wherein the scheduling
information comprises one or more of the following: a carrier
indicator; a location of the one or more sidelink radio resources
in the time domain; a location of the one or more sidelink radio
resources in the frequency domain; a retransmission related
parameter; a semi-persistent scheduling (SPS) related
parameter.
18. The base station of claim 13, wherein the communication
interface is configured to receive from the network entity one or
more sidelink radio interface configuration parameters for a
UE.
19. The base station of claim 13, wherein the one or more sidelink
radio interface configuration parameters comprise one or more radio
resource control (RRC) parameters controlling the operation of at
least one of the medium access control (MAC) layer and the physical
(PHY) layer for sidelink communication.
20. The base station of claim 13, wherein the one or more radio
resource control (RRC) parameters controlling the operation of at
least one of the medium access control (MAC) layer and the physical
(PHY) layer for sidelink communication comprise one or more of the
following: a radio resource pool configuration parameter; a zone
configuration parameter; a radio resource selection configuration
parameter; a semi-persistent scheduling (SPS) configuration
parameter; a measurement configuration parameter.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/EP2017/082688, filed on Dec. 13, 2017, which
claims priority to International Patent Application No.
PCT/EP2017/063050, filed on May 30, 2017. The disclosures of the
aforementioned applications are hereby incorporated by reference in
their entireties.
TECHNICAL FIELD
[0002] In general, the present invention relates to the field of
wireless communication. In particular, the invention relates to
devices and methods for PLMN operator independent management of V2X
sidelink communication.
BACKGROUND
[0003] In 3GPP (3rd Generation Partnership Project) cellular
networks--such as LTE (Long Term Evolution) or 5G--supporting V2X
(Vehicle-to-Everything) sidelink communication, sidelink (SL) radio
resources are generally controlled by a Public Land Mobile Network
(PLMN) operator. User equipments (UEs) belonging to different PLMN
operators are assumed to transmit using different spectral bands
(i.e., different carrier frequencies). However, this precludes the
possibility of spectrum sharing among operators. For some
safety-of-life applications, the future spectrum allocation for V2X
sidelink communication may not belong to a specific operator, but
rather be shared by multiple operators.
[0004] There are two modes of operation for V2X communication in
3GPP Rel-14, namely over the PC5 (sidelink) interface and over the
LTE-Uu (uplink/downlink) interface. In the sidelink mode of
operation, which is referred to as V2X sidelink communication, the
user equipments (UEs) can communicate with each other directly over
the PC5 interface.
[0005] Generally, a UE supporting V2X sidelink communication can
operate in two modes for resource allocation.
[0006] In the first resource allocation mode, which is referred to
as scheduled resource allocation or sidelink transmission mode 3,
the UE requests transmission resources from a base station (BS),
and the BS schedules dedicated resources to the UE for transmission
of sidelink control information (SCI) and sidelink user data.
[0007] In the second resource allocation mode, which is referred to
as UE autonomous resource selection or sidelink transmission mode
4, the UE on its own selects resources from resource pools to
transmit SCI and data.
[0008] In order to prevent interference among V2X sidelink
transmissions in the second operation mode, 3GPP Radio Resource
Control (RRC) specifications introduce two features in Release 14,
namely "zones" and "sensing". The world is divided into
geographical zones. A zone is a periodically repeating geographic
region. The UE selects a radio resource pool based on the zone it
is located in. Based on channel sensing within the selected radio
resource pool, the UE selects specific sidelink radio resources for
transmission and may reserve periodically recurring (i.e.,
semi-persistent) sidelink radio resources.
[0009] Different operators use different V2X sidelink
configurations (e.g., radio resource pools, zones, etc.) specified
in sl-V2X-ConfigCommon, sl-V2X-ConfigDedicated, etc. If UEs
belonging to different operators transmit on the same carrier
frequency without a common configuration, then UEs in different
zones may select the same resource pool, leading to inter-zone
interference.
[0010] In the scheduled resource allocation mode, the sidelink
scheduler at the BS uses UE geographical location information
(e.g., obtained from periodic position reports) to ensure
orthogonal time/frequency resources are allocated to nearby UEs,
thus preventing interference. Each operator, however, has its own
sidelink scheduler, and is unaware of UEs belonging to other
operators (including their geographical location). If nearby UEs
belonging to different operators transmit on the same carrier
frequency, the operator-centric sidelink schedulers won't be able
to prevent interference.
[0011] Thus, there is a need for improved devices and methods for
managing V2X sidelink communication in a PLMN operator independent
manner.
SUMMARY
[0012] It is an object of the invention to provide for improved
devices and methods for managing V2X sidelink communication in a
PLMN operator independent manner.
[0013] The foregoing and other objects are achieved by the subject
matter of the independent claims. Further implementation forms are
apparent from the dependent claims, the description and the
figures.
[0014] Generally, embodiments of the invention are based on the
idea of moving the intelligence (control of sidelink radio
resources, including sidelink scheduling) from the operator's radio
access network (RAN) to a network entity accessible by different
operators, while keeping the standard interface (RRC/MAC/PHY
control signaling messages) between a base station (BS) and a user
equipment (UE) unmodified, so as to have no impact on the UE
architecture. The UE is thus unaware that the sidelink radio
resources are being controlled by a network entity located, for
instance, in the cloud and not in the operator's RAN. In
embodiments of the invention, a network entity, in particular a
cloud server, communicates with an operator's BS via a new
interface to control the configuration parameters of the BS for V2X
sidelink communication. The BS and UE exchange control signaling
related to V2X sidelink communication as usual via the standard
interface specified by 3GPP. Thus, the UE is unaware that sidelink
radio resources are controlled from outside the RAN. A key
advantage provided by embodiments of the invention is that no
changes to the current 3GPP Rel-14 UE architecture are required,
thus having no impact on the UE.
[0015] More specifically, according to a first aspect, the
invention relates to a network entity, in particular a cloud
server, comprising a processor being configured to control radio
resources, in particular sidelink radio resources, on behalf of one
or more, in particular two, mobile networks (PLMNs). A cloud server
in the meaning of the invention is an entity that is configured to
communicate with entities of a PLMN, but may or may not be itself
part of a PLMN, i.e., it may or may not be related to a PLMN ID. A
PLMN is a Public Land Mobile Network, which is run by a certain
operator. In particular, a PLMN can be identified by a PLMN ID,
wherein the PLMN ID can be a unique identifier of the PLMN in a
relevant area.
[0016] In a further implementation form of the first aspect, the
processor is configured to control sidelink radio resources for
transmission by a first UE of a first PLMN and/or a second UE of a
second PLMN.
[0017] In a further implementation form of the first aspect, the
processor is configured to perform dynamic and/or semi-persistent
scheduling of sidelink transmissions by allocating one or more
sidelink radio resources to a first UE of the first PLMN and/or to
a second UE of the second PLMN; and/or set the value of one or more
sidelink radio interface configuration parameters for the first UE
of the first PLMN and/or for the second UE of the second PLMN.
[0018] In a further implementation form of the first aspect, the
radio resources are located on a same carrier.
[0019] In a further implementation form of the first aspect, the
network entity further comprises a communication interface for
communication with a first base station (BS) of the first PLMN
and/or a second BS of the second PLMN.
[0020] In a further implementation form of the first aspect, the
communication interface is configured to transmit scheduling
information to the first BS, wherein the scheduling information
specifies one or more sidelink radio resources allocated to the
first UE for transmission of sidelink control information and/or
sidelink user data; and/or transmit scheduling information to the
second BS, wherein the scheduling information specifies one or more
sidelink radio resources allocated to the second UE for
transmission of sidelink control information and/or sidelink user
data.
[0021] In case the network entity is configured to transmit
scheduling information to the first and to the second BS, this
scheduling information need not be the same scheduling
information.
[0022] In a further implementation form of the first aspect, the
scheduling information comprises one or more of the following:
[0023] a carrier indicator; [0024] a location of the one or more
sidelink radio resources in the time domain; [0025] a location of
the one or more sidelink radio resources in the frequency domain;
[0026] a retransmission related parameter; [0027] a semi-persistent
scheduling (SPS) related parameter.
[0028] In a further implementation form of the first aspect, the
communication interface is configured to transmit the one or more
sidelink radio interface configuration parameters for the first UE
to the first BS; and/or transmit the one or more sidelink radio
interface configuration parameters for the second UE to the second
BS.
[0029] In a further implementation form of the first aspect, the
one or more sidelink radio interface configuration parameters
comprise one or more radio resource control (RRC) parameters
controlling the operation of the medium access control (MAC) layer
and/or the physical (PHY) layer for sidelink communication.
[0030] In a further implementation form of the first aspect, the
one or more radio resource control (RRC) parameters controlling the
operation of the medium access control (MAC) layer and/or the
physical (PHY) layer for sidelink communication comprise one or
more of the following: [0031] a radio resource pool configuration
parameter; [0032] a zone configuration parameter; [0033] a radio
resource selection configuration parameter; [0034] a
semi-persistent scheduling (SPS) configuration parameter; [0035] a
measurement configuration parameter.
[0036] In a further implementation form of the first aspect, the
communication interface is further configured to receive from the
first BS and/or from the second BS one or more sidelink radio
resource request parameters and/or one or more measurements.
[0037] In a further implementation form of the first aspect, the
one or more sidelink radio resource request parameters comprise one
or more of the following: [0038] a carrier frequency for
transmitting and/or receiving by a UE; [0039] a destination ID;
[0040] a parameter for semi-persistent scheduling (SPS), in
particular periodicity, timing offset, priority and/or message
size; and the one or more measurements comprise one or more of the
following: [0041] a geographic location of a UE; [0042] a received
signal strength in one or more radio resources; [0043] a sidelink
buffer status.
[0044] According to a second aspect, the invention relates to a
corresponding method for operating a network entity, in particular
a cloud server, comprising the step of controlling radio resources,
in particular sidelink radio resources, on behalf of one or more,
in particular two, mobile networks (PLMNs).
[0045] The method according to the second aspect of the invention
can be performed by the network entity according to the first
aspect of the invention. Further features of the method according
to the second aspect of the invention result directly from the
functionality of the network entity according to the first aspect
of the invention and its different implementation forms.
[0046] According to a third aspect, the invention relates to a base
station (BS) of a PLMN, comprising a processor configured to
process control plane information related to control of radio
resources, in particular sidelink radio resources, and a
communication interface configured to transmit and/or receive
to/from a network entity, in particular a cloud server, said
control plane information.
[0047] In a further implementation form of the third aspect, the
communication interface is configured to transmit to the network
entity one or more sidelink radio resource request parameters
and/or one or more measurements.
[0048] In a further implementation form of the third aspect, the
one or more sidelink radio resource request parameters comprise one
or more of the following: [0049] a carrier frequency for
transmitting and/or receiving by a UE; [0050] a destination ID;
[0051] a parameter for semi-persistent scheduling (SPS), in
particular periodicity, timing offset, priority and/or message
size; and the one or more measurements comprise one or more of the
following: [0052] a geographic location of a UE; [0053] a received
signal strength in one or more radio resources; [0054] a sidelink
buffer status.
[0055] In a further implementation form of the third aspect, the
communication interface is configured to receive from the network
entity scheduling information, wherein the scheduling information
specifies one or more sidelink radio resources allocated to a UE
for transmission of sidelink control information and/or sidelink
user data.
[0056] In a further implementation form of the third aspect, the
scheduling information comprises one or more of the following:
[0057] a carrier indicator; [0058] a location of the one or more
sidelink radio resources in the time domain; [0059] a location of
the one or more sidelink radio resources in the frequency domain;
[0060] a retransmission related parameter; [0061] a semi-persistent
scheduling (SPS) related parameter.
[0062] In a further implementation form of the third aspect, the
communication interface is configured to receive from the network
entity one or more sidelink radio interface configuration
parameters for a UE.
[0063] In a further implementation form of the third aspect, the
one or more sidelink radio interface configuration parameters
comprise one or more radio resource control (RRC) parameters
controlling the operation of the medium access control (MAC) layer
and/or the physical (PHY) layer for sidelink communication.
[0064] In a further implementation form of the third aspect, the
one or more radio resource control (RRC) parameters controlling the
operation of the medium access control (MAC) layer and/or the
physical (PHY) layer for sidelink communication comprise one or
more of the following: [0065] a radio resource pool configuration
parameter; [0066] a zone configuration parameter; [0067] a radio
resource selection configuration parameter; [0068] a
semi-persistent scheduling (SPS) configuration parameter; [0069] a
measurement configuration parameter.
[0070] According to a fourth aspect, the invention relates to a
corresponding method for operating a base station (BS) of a PLMN,
comprising a communication interface configured to transmit and/or
receive to/from a network entity, in particular a cloud server,
control plane information related to control of radio resources, in
particular sidelink radio resources.
[0071] The method according to the fourth aspect of the invention
can be performed by the base station according to the third aspect
of the invention. Further features of the method according to the
fourth aspect of the invention result directly from the
functionality of the base station according to the third aspect of
the invention and its different implementation forms.
[0072] According to a fifth aspect, the invention relates to a
computer program comprising program code for performing the method
of the second aspect or the method of the fourth aspect when
executed on a computer or a processor.
[0073] The invention can be implemented in hardware and/or
software.
BRIEF DESCRIPTION OF DRAWINGS
[0074] Further embodiments of the invention will be described with
respect to the following figures, wherein:
[0075] FIG. 1 shows a schematic diagram illustrating a V2X
communication system including a network entity according to an
embodiment and a base station according to an embodiment;
[0076] FIG. 2 shows adjacent PSCCH (Physical Sidelink Control
Channel) and PSSCH (Physical Sidelink Shared Channel) radio
resources in an exemplary grid of sidelink radio resources; and
[0077] FIG. 3 shows a schematic diagram illustrating some further
aspects of the V2X communication system of FIG. 1.
[0078] In the various figures, identical reference signs will be
used for identical or at least functionally equivalent
features.
DESCRIPTION OF EMBODIMENTS
[0079] In the following description, reference is made to the
accompanying drawings, which form part of the disclosure, and in
which are shown, by way of illustration, specific aspects in which
the present invention may be placed. It is understood that other
aspects may be utilized and structural or logical changes may be
made without departing from the scope of the present invention. The
following detailed description, therefore, is not to be taken in a
limiting sense, as the scope of the present invention is defined by
the appended claims.
[0080] For instance, it is understood that a disclosure in
connection with a described method may also hold true for a
corresponding device or system configured to perform the method and
vice versa. For example, if a specific method step is described, a
corresponding device may include a unit to perform the described
method step, even if such unit is not explicitly described or
illustrated in the figures. Further, it is understood that the
features of the various exemplary aspects described herein may be
combined with each other, unless specifically noted otherwise.
[0081] FIG. 1 illustrates a V2X communication system 100 including
a network entity 110 according to an embodiment. As can be taken
from the detailed view of FIG. 1 and as will be explained in more
detail further below, the network entity 110, which in the
embodiment shown in FIG. 1 is implemented as a single cloud server
110 located in the Internet 112, comprises a processor 110a being
configured to control radio resources, in particular sidelink radio
resources, on behalf of one or more mobile networks (PLMNs) 120,
130. In the embodiment shown in FIG. 1, the processor 110a of the
cloud server 110 is configured to control sidelink radio resources
for transmission by a first user equipment (UE) 121 of a first PLMN
120 and a second UE 131 of a second PLMN 130. As used herein, a
PLMN is a Public Land Mobile Network, which is run by a certain
operator. In particular, a PLMN can be identified by a PLMN ID,
wherein the PLMN ID can be a unique identifier of the PLMN in a
relevant area.
[0082] As can be taken from the detailed view shown in FIG. 1, the
network entity 110 further comprises a communication interface
110b, which is configured to communicate with a first base station
(BS) 123 of the first PLMN 120 and a second BS 133 of the second
PLMN 130. Likewise, the first BS 123 and the second BS 133 each
comprise a processor (e.g. the processor 133a of the BS 133 shown
in FIG. 1) configured to process control plane information related
to control of sidelink radio resources, and a communication
interface (e.g. the communication interface 133b of the BS 133
shown in FIG. 1) configured to communicate with the network entity
110. As illustrated in the exemplary embodiment shown in FIG. 1,
the first UE 121 and second UE 131 could be implemented as part of
a respective vehicle, such as in the form of an on-board unit. As
will be appreciated, however, the first UE 121 and second UE 131
could be implemented as mobile phones or other types of user
equipments as well.
[0083] As will be described in more detail further below, the
communication interface 133b of the respective BS 123, 133 is
configured to transmit and/or receive to/from the network entity
110 control plane information related to the control of radio
resources, in particular sidelink radio resources.
[0084] Before describing in more detail further embodiments of the
invention, in the following some further technical background will
be provided, which can be helpful for understanding different
aspects of the present invention.
[0085] In an embodiment, the UEs 121, 131 supporting V2X sidelink
communication can operate in two modes for resource allocation.
[0086] In the first resource allocation mode, which is referred to
as scheduled resource allocation, the UE 121, 131 requests
transmission resources from a base station 123, 133, and the base
station schedules dedicated resources to the UE for transmission of
sidelink control information (SCI) and sidelink user data.
[0087] In the second resource allocation mode, which is referred to
as UE autonomous resource selection, the UE 121, 131 on its own
selects resources from resource pools to transmit SCI and data. The
UE 121, 131 selects a resource pool based on the zone the UE 121,
131 is located in. Based on sensing, the UE 121, 131 can select
specific sidelink resources and may reserve periodically recurring
(i.e., semi-persistent) sidelink resources.
[0088] The UE 121, 131 may report geographical location information
to the respective base station 123, 133. The UE 121, 131 can be
configured to report the complete UE geographical location
information based on periodic reporting.
[0089] Geographical zones can be configured by the respective base
station 123, 133 (e.g., SystemInformationBlockType21) or
preconfigured (e.g., SL-V2X-Preconfiguration). When zones are
configured, the world is divided into geographical zones using a
single fixed reference point, zone length and zone width, from
which the UE 121, 131 determines the identity of the zone it is
located in.
[0090] In the following, a summary of radio resource control (RRC)
related procedures for V2X sidelink communication is provided,
which are relevant for embodiments of the invention.
[0091] The information element (IE) SystemInformationBlockType21
can contain the following common configuration information related
to V2X sidelink communication (i.e., sl-V2X-ConfigCommon):
v2x-CommTxPoolNormalCommon (list of up to 8 transmit resource pools
for normal conditions for transmission in RRC IDLE);
v2x-CommTxPoolExceptional (one transmit resource pool for
exceptional conditions (e.g., handover)); v2x-CommRxPool (list of
up to 16 receive resource pools); v2x-SyncConfig (synchronization
configuration for Sidelink Synchronization Signal (SLSS)
transmission); v2x-InterFreqInfoList (list of up to 8 possible
carrier frequencies for V2X sidelink communication);
v2x-ResourceSelectionConfig (sensing configuration for UE
autonomous resource selection); and zoneConfig (zone configuration
(length, width, etc.)).
[0092] Moreover, the v2x-ResourceSelectionConfig includes:
probResourceKeep (probability with which the UE keeps the current
resource at the end of a resource reselection period);
pssch-TxConfigList (a list of up to 16 SL-PSSCH-TxConfig
configurations, including synchronization reference type
(typeTxSync: gnss, enb, ue); and PSSCH transmission parameters
(minMCS-PSSCH, maxMCS-PSSCH, minRB-NumberPSSCH, maxRB-NumberPSSCH,
allowedRetxNumberPSSCH), restrictResourceReservationPeriodList
(list of up to 16 values allowed for the resource reservation
interval), and thresPSSCH-RSRP-List (list of 64 threshold values
used when excluding resources).
[0093] In an embodiment, the IE SL-CommResourcePoolV2X specifies
parameters for a specific resource pool, including: sl-Subframe
(the bitmap used to determine the subframes belonging to the
resource pool); adjacencyPSCCH-PSSCH (whether a UE 121, 131 shall
transmit PSCCH and PSSCH in adjacent physical resource blocks
(PRBs)); sizeSubchannel (number of PRBs of each subchannel in the
corresponding resource pool); numSubchannel (number of subchannels
in the corresponding resource pool); startRB-Subchannel (lowest PRB
index of the subchannel with the lowest index); startRB-PSCCH-Pool
(lowest PRB index of the PSCCH pool); dataTxParameters (parameters
for sidelink power control); and zoneID (zone identity for which
the UE 121, 131 shall use this resource pool).
[0094] When the UE 121, 131 receives RRCConnectionReconfiguration
including sl-V2X-ConfigDedicated, it can perform the following
dedicated configuration procedure.
[0095] If the field commTxResources is set to scheduled, the UE
121, 131 requests the base station to assign transmission resources
based on sidelink Buffer Status Reports (Sidelink BSR) from the UE
121, 131. The field commTxResources also specifies the resource
pool (v2x-SchedulingPool) and modulation and coding scheme (mcs) to
be used by the UE 121, 131. Within the allocated pool, the specific
resources for PSSCH transmission are determined based on the
content of the SL Grant received via Downlink Control Information
(DCI format 5A) on PDCCH (Physical Downlink Control Channel).
[0096] If the field commTxResources is set to ue-Selected, the UE
121, 131 transmits V2X sidelink data based on sensing using one of
the resource pools indicated by v2x-commTxPoolNormalDedicated. The
sensing configuration is specified in
v2x-CommTxPoolSensingConfig.
[0097] In scheduled mode, if semi-persistent scheduling (SPS) is
enabled, an sl-V-SPS-RNTI is included in the field SPS-Config
within the IE radioResourceConfigDedicated sent via the
RRCConnectionReconfiguration message. Each SL SPS configuration
SPS-ConfigSL is specified by the following parameters:
sps-ConfigIndex indicates the index of the SL SPS configuration;
semiPersistSchedIntervalSL indicates the time interval between
consecutive transmission opportunities (20 ms, 50 ms, 100 ms, 200
ms, 300 ms, 400 ms, 500 ms, 600 ms, 700 ms, 800 ms, 900 ms, 1000
ms).
[0098] A UEAssistanceInformation message can be used for the
indication of UE assistance information to the respective base
station 123, 133. This message includes sps-AssistanceInformation
to assist the base station to configure SPS, e.g., by providing the
traffic characteristics (periodicity, timing offset, priority,
message size, etc.) of sidelink logical channel(s)
(trafficPatternInfoListSL).
[0099] In an embodiment, an RRC_CONNECTED UE 121, 131 sends a
SidelinkUEInformation message to the respective serving base
station 123, 133 in order to request assignment of dedicated
sidelink resources. The SidelinkUEInformation message can include
the following information: v2x-CommRxInterestedFreq indicates the
index of the frequency (in v2x-InterFreqInfoList broadcast in
SystemInformationBlockType21) on which the UE is interested to
receive V2X sidelink communication. The V2X sidelink communication
transmission resource request (v2x-CommTxResourceReq) includes:
v2x-CommTxFreq indicating the index of the frequency on which the
UE is interested to transmit V2X sidelink communication (same value
as indicated in v2x-CommRxInterestedFreq); and
v2x-DestinationInfoList containing a list of up to 16 Destination
Layer-2 IDs for V2X sidelink communication.
[0100] In an embodiment, if the respective UE 121, 131 is in
coverage and has V2X sidelink data to be transmitted, it operates
in one of the following ways.
[0101] If the UE 121, 131 is in RRC_CONNECTED and the field
commTxResources is set to scheduled, it requests the base station
to assign dedicated resources for transmission. If commTxResources
is set to ue-Selected, the UE transmits based on sensing using one
of the resource pools indicated by
v2x-commTxPoolNormalDedicated.
[0102] If the UE 121, 131 is in RRC IDLE, it transmits based on
sensing using one of the resource pools indicated by
v2x-CommTxPoolNormalCommon.
[0103] When out of coverage, the UE 121, 131 transmits V2X sidelink
data based on sensing using one of the resource pools indicated by
v2x-CommTxPoolList in SL-V2X-Preconfiguration.
[0104] In an embodiment, for resource pool selection, the UE 121,
131 only uses the resource pool which corresponds to its
geographical coordinates, if zoneConfig is included in
SystemInformationBlockType21 or in SL-V2X-Preconfiguration. The UE
121, 131 selects a pool of resources which includes a zoneID equal
to the calculated zone identity.
[0105] In an embodiment, for V2X sidelink related measurement
configuration and reporting, the RRCConnectionReconfiguration
message is used to configure (measConfig) which measurements should
be performed by the UE 121, 131 in relation to V2X sidelink
communication as well as the reporting configuration
(reportConfig), e.g., how often they should be reported
(reportInterval) and whether location information should be
included (includeLocationInfo). The MeasurementReport message
includes the measurement results (measResults), e.g., the
geographic location (locationInfo) of the UE 121, 131.
[0106] In the following, a summary of medium access control (MAC)
layer related procedures for V2X sidelink communication is
provided, which are relevant for embodiments of the invention.
[0107] According to 3GPP Rel-14 V2X sidelink communication
specifications, in order to transmit on the Sidelink Shared Channel
(SL-SCH), the corresponding MAC layer must have at least one SL
Grant. New transmissions and retransmissions are performed on the
resource indicated in the SL Grant and with the Modulation and
Coding Scheme (MCS) configured by upper layers or selected by the
UE 121, 131 between minMCS-PSSCH and maxMCS-PSSCH.
[0108] For scheduled resource allocation (sidelink transmission
mode 3), the SL Grant can be derived from the DCI format 5A
received on PDCCH from the respective base station 123, 133,
containing the following information: carrier indicator; lowest
index of the subchannel allocation of the initial transmission
(L.sub.init); frequency resource location of initial transmission
and retransmission, indicated by a resource indication value (RIV);
time gap between initial transmission and retransmission
(SF.sub.gap); SL SPS configuration index (SPS case) and
activation/release indication (SPS case).
[0109] If the MAC layer is configured with at least one SL SPS
configuration and the received SL Grant has been received on the
PDCCH for the MAC layer's sl-V-SPS-RNTI, the MAC layer
(re-)initializes the configured SL Grant and considers sequentially
that the Nth grant occurs in the subframe for which:
(10SFN+subframe)=[(10SFN.sub.start time+subframe.sub.start
time)+NsemiPersistSchedIntervalSL] modulo 10240,
wherein SFN.sub.start time and subframe.sub.start time correspond
to the (re-)initialization time.
[0110] In an embodiment, for UE autonomous resource selection
(sidelink transmission mode 4), the UE 121, 131 (re)selects PSSCH
resources autonomously and semi-persistently based on channel
sensing. At the end of each reselection period, the UE 121, 131
keeps the previously selected resource with a probability
probResourceKeep. If the UE 121, 131 does not keep the previously
selected resource, the UE: selects the number of retransmissions (0
or 1) as configured in allowedRetxNumberPSSCH; selects an amount of
frequency resources (number of contiguous subchannels L.sub.subCH)
within the range configured by upper layers between
minRB-NumberPSSCH and maxRB-NumberPSSCH; and sets the resource
reservation interval P.sub.rsvp_TX to one of the allowed values
configured by upper layers in restrictResourceReservationPeriod.
The UE 121, 131 then randomly selects a resource and uses it to
select a set of periodic resources spaced by the resource
reservation interval P.sub.rsvp_TX.
[0111] A candidate resource is defined as a set of L.sub.subCH
contiguous subchannels in a given subframe. Any set of L.sub.subCH
contiguous subchannels in the PSSCH resource pool within a certain
time window (so as to fulfill the latency requirement) corresponds
to a candidate resource. The UE 121, 131 excludes resources for
which either it has no measurement information or which are
reserved by nearby UEs with an associated PSSCH-RSRP above a
certain (priority-dependent) threshold. From the remaining
resources, it selects randomly among the best resources in terms of
S-RSSI (Sidelink Received Signal Strength Indicator).
[0112] If retransmissions are enabled, the UE 121, 131 follows the
same procedure to select a set of periodic resources for
retransmissions. The UE 121, 131 may also reselect a resource at
any time if the data available for transmission does not fit in the
selected resource.
[0113] In sidelink transmission mode 3, a sidelink buffer status
reporting (Sidelink BSR) procedure can be used to provide the
serving base station 123, 133 with information about the amount of
SL data available for transmission.
[0114] RRC controls BSR reporting for SL by configuring the
relevant timers. Each sidelink logical channel belongs to a
Destination ID and is allocated to a Logical Channel Group (LCG)
depending on its priority and the mapping between LCG ID and
priority provided by upper layers in logicalChGroupInfoList.
[0115] For each reported group, Sidelink BSR MAC control elements
consist of: destination index, LCG ID and buffer size (bytes).
[0116] In the following, a summary of physical (PHY) layer related
procedures for V2X sidelink communication is provided, which are
relevant for embodiments of the invention.
[0117] FIG. 2 illustrates an example of adjacent PSCCH and PSSCH
resources.
[0118] For determining a PSSCH resource pool, the set of subframes
that may belong to a PSSCH resource pool is specified as part of
the resource pool configuration by means of a bitmap.
[0119] The physical resource block (PRB) pool consists of N subCH
subchannels, where N.sub.subCH is given by a higher layer parameter
numSubchannel, where each subchannel consists of a set of
n.sub.subCHsize contiguous PRBs (sizeSubchannel). The starting PRB
number n.sub.subCHRBstart for the resource pool is specified by a
higher layer parameter startRBSubchannel.
[0120] There are two possible ways of transmitting PSCCH: adjacent
and non-adjacent to the PSSCH. Which one is used is part of the
resource pool configuration, as specified by the parameters
adjacency PSCCH-PSSCH and startRBPSCCHPool.
[0121] The set of subframes and resource blocks for PSSCH
transmission is determined by the resource used for the PSCCH
transmission containing the associated SCI format 1, and:
[0122] frequency resource location of the initial transmission and
retransmission given by a resource indication value (RIV)
corresponding to a starting subchannel index
(n.sub.subCH.sup.start) and a length in terms of contiguously
allocated subchannels (L.sub.subCH.gtoreq.1); and retransmission
related parameters (e.g., time gap between initial transmission and
retransmission field (SF.sub.gap), retransmission index).
[0123] In sidelink transmission mode 4, the selected resource for
PSSCH transmission can be semi-persistent, with a resource
reservation interval P.sub.rsvp_TX determined by higher layers.
[0124] SCI format 1 is transmitted in two PRBs in each subframe
where the corresponding PSSCH is transmitted.
[0125] The following information is transmitted by means of SCI
format 1: priority, modulation and coding scheme, resource
reservation interval, frequency resource location of initial
transmission and retransmission given by a resource indication
value (RIV) and retransmission related parameters (e.g., time gap
between initial transmission and retransmission (SF.sub.gap),
retransmission index).
[0126] FIG. 3 illustrates the protocol stacks implemented in the
UEs 121, 131 and the base stations 123, 133 of the V2X
communication system 100 of FIG. 1. In the embodiment of FIG. 3,
the network entity 110 is implemented as a cloud server 110 acting
as a V2X Sidelink Radio Controller within the V2X communication
system 100.
[0127] In an embodiment, the cloud server 110, the base stations
123, 133 and the UEs 121, 131 are configured to interact in the
following way.
[0128] The RRC layer in a base station 123, 133 may forward to the
V2X Sidelink Radio Controller, i.e., the cloud server 110,
measurement results (e.g., measResults, including locationInfo) and
UE assistance information (e.g., sps-AssistanceInformation
specifying traffic characteristic parameters for semi-persistent
scheduling) received from the UEs 121, 131.
[0129] The V2X Sidelink Radio Controller, i.e., the cloud server
110, transmits to the RRC layer of the base station 123, 133
configuration parameters for V2X sidelink communication. In an
embodiment, these parameters may include: radio resource pools
(v2x-CommTxPool, v2x-CommRxPool); zone configuration parameters
(zoneConfig); sensing configuration parameters
(v2x-resourceSelectionConfig); semi-persistent scheduling (SPS)
configuration parameters (SP S-Config) and/or measurement
configuration parameters (measConfig).
[0130] These parameters will be used by the respective base station
123, 133 to configure the respective UE 121, 131
(sl-V2X-ConfigCommon, sl-V2X-ConfigDedicated) via broadcast control
signaling (SystemInformationBlockType21) or dedicated control
signaling (RRCConnectionSetup, RRCConnectionReconfiguration).
[0131] The MAC layer in the respective base station 123, 133 may
forward to the V2X Sidelink Radio Controller, i.e., the cloud
server 110, sidelink buffer status information received from the
respective UE 121, 131 (via Sidelink BSR MAC Control Elements).
This can be used by the V2X Sidelink Scheduler of the cloud server
110 for dynamic (i.e., non-persistent) scheduling of sidelink
transmissions. In case of semi-persistent scheduling (SPS), the
sps-AssistanceInformation forwarded by the RRC layer of the
respective base station 123, 133 can be taken into account by the
V2X Sidelink Scheduler.
[0132] Based on the scheduling decision by the V2X Sidelink
Scheduler, the cloud server 110 transmits the corresponding
time/frequency resource allocation information to the respective
base station 123, 133, including one or more of the following: the
ID of the respective UE 121, 131 to which the scheduling decision
applies; a carrier indicator; location of allocated resources in
the time domain; location of allocated resources in the frequency
domain; retransmission related parameters (e.g., time gap between
initial transmission and retransmission); SPS related parameters
(e.g., SL SPS configuration index, activation/release indication).
The respective base station 123, 133 then uses these values to
generate the SL Grant and transmits it to the corresponding UE 121,
131 via Downlink Control Information (DCI format 5A) on PDCCH
(Physical Downlink Control Channel).
[0133] For synchronization purposes, the cloud server 110 and the
base stations 123, 133 may utilize the UTC time (e.g., from a GNSS
synchronization source) to calculate the Direct Frame Number (DFN)
and subframe number, according to the procedure specified for the
UE 121, 131 in Section 5.10.14 of the standard specification 3GPP
TS 36.331, "LTE; Evolved Universal Terrestrial Radio Access
(E-UTRA); Radio Resource Control (RRC); Protocol
specification".
[0134] Since, according to embodiments of the invention, V2X
sidelink configuration parameters for UEs belonging to different
operators are controlled by a single entity, namely the network
entity 110, the limitations of the conventional operator-centric
design in a shared spectrum scenario can be overcome. More
specifically, in the distributed mode (UE autonomous resource
selection), inter-zone interference is prevented by having a common
radio resource pool configuration and zone configuration provided
by the network entity 110. In the centralized mode (scheduled
resource allocation), having the network entity 110 act as a single
sidelink scheduler ensures orthogonal resources are allocated to
nearby UEs, regardless of the operator the UE belongs to.
[0135] While a particular feature or aspect of the disclosure may
have been disclosed with respect to only one of several
implementations or embodiments, such feature or aspect may be
combined with one or more other features or aspects of the other
implementations or embodiments as may be desired and advantageous
for any given or particular application. Furthermore, to the extent
that the terms "include", "have", "with", or other variants thereof
are used in either the detailed description or the claims, such
terms are intended to be inclusive in a manner similar to the term
"comprise". Also, the terms "exemplary", "for example" and "e.g."
are merely meant as an example, rather than the best or optimal.
The terms "coupled" and "connected", along with derivatives may
have been used. It should be understood that these terms may have
been used to indicate that two elements cooperate or interact with
each other regardless of whether they are in direct physical or
electrical contact, or they are not in direct contact with each
other.
[0136] Although specific aspects have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that a variety of alternate and/or equivalent
implementations may be substituted for the specific aspects shown
and described without departing from the scope of the present
disclosure. This application is intended to cover any adaptations
or variations of the specific aspects discussed herein.
[0137] Although the elements in the following claims are recited in
a particular sequence with corresponding labeling, unless the claim
recitations otherwise imply a particular sequence for implementing
some or all of those elements, those elements are not necessarily
intended to be limited to being implemented in that particular
sequence.
[0138] Many alternatives, modifications, and variations will be
apparent to those skilled in the art in light of the above
teachings. Of course, those skilled in the art readily recognize
that there are numerous applications of the invention beyond those
described herein. While the present invention has been described
with reference to one or more particular embodiments, those skilled
in the art recognize that many changes may be made thereto without
departing from the scope of the present invention. It is therefore
to be understood that within the scope of the appended claims and
their equivalents, the invention may be practiced otherwise than as
specifically described herein.
* * * * *