U.S. patent application number 16/833261 was filed with the patent office on 2020-07-16 for control plane based small data service.
The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Santosh Paul ABRAHAM, Miguel GRIOT, Soo Bum LEE, Sebastian SPEICHER, Haris ZISIMOPOULOS.
Application Number | 20200228960 16/833261 |
Document ID | 20200228960 / US20200228960 |
Family ID | 65721174 |
Filed Date | 2020-07-16 |
Patent Application | download [pdf] |
View All Diagrams
United States Patent
Application |
20200228960 |
Kind Code |
A1 |
ABRAHAM; Santosh Paul ; et
al. |
July 16, 2020 |
CONTROL PLANE BASED SMALL DATA SERVICE
Abstract
A core network receives data from at least one of an Application
Function (AF), a Data Network (DN), or a User Equipment (UE). A
Session Management Function (SMF) processes the data for transport
with a low overhead as a session management (SM) payload over a Non
Access Stratum (NAS) protocol. The data may be received from an
.DELTA.F or DN external to the core network and may be processed to
transport the data to the UE based as a SM payload. The data may be
received as uplink data from a UE, e.g., in an SM payload. The SMF
may processed the SM payload to obtain the data and may transport
the data to the AF or DN. The SMF may perform IP header
compression, data encryption based on an SMF encryption key, and/or
buffering of data for a UE in an idle mode.
Inventors: |
ABRAHAM; Santosh Paul; (San
Diego, CA) ; GRIOT; Miguel; (La Jolla, CA) ;
SPEICHER; Sebastian; (Wallisellen, CH) ;
ZISIMOPOULOS; Haris; (London, GB) ; LEE; Soo Bum;
(San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Family ID: |
65721174 |
Appl. No.: |
16/833261 |
Filed: |
March 27, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16128127 |
Sep 11, 2018 |
|
|
|
16833261 |
|
|
|
|
62560097 |
Sep 18, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 28/06 20130101;
Y02D 70/142 20180101; Y02D 70/1242 20180101; Y02D 70/162 20180101;
Y02D 70/144 20180101; H04W 8/02 20130101; Y02D 70/00 20180101; H04W
76/27 20180201; H04L 67/12 20130101; H04W 52/0229 20130101; H04W
80/04 20130101; H04L 69/04 20130101; Y02D 70/1262 20180101; Y02D
70/26 20180101; H04L 67/14 20130101; H04W 4/70 20180201; H04W 48/18
20130101; H04W 12/04 20130101; H04W 28/0215 20130101; H04W 8/18
20130101; Y02D 70/21 20180101; H04W 12/0013 20190101 |
International
Class: |
H04W 8/18 20060101
H04W008/18; H04L 29/08 20060101 H04L029/08; H04W 28/02 20060101
H04W028/02; H04W 4/70 20060101 H04W004/70; H04W 12/00 20060101
H04W012/00; H04L 29/06 20060101 H04L029/06; H04W 8/02 20060101
H04W008/02; H04W 12/04 20060101 H04W012/04; H04W 28/06 20060101
H04W028/06; H04W 48/18 20060101 H04W048/18; H04W 52/02 20060101
H04W052/02 |
Claims
1. A method of wireless communication at a user equipment (UE),
comprising: establishing a session with a session management
function (SMF) for communication of user data below a size
threshold; and communicating the user data with at least one of an
Application Function (AF) or a Data Network (DN), wherein the user
data is communicated with the SMF for transport via an Access and
Mobility Management Function (AMF) as a Session Management (SM)
payload over a Non Access Stratum (NAS) protocol.
2. The method of claim 1, wherein the communicating the user data
comprises: receiving the user data from the AF as the SM payload
received from the SMF.
3. The method of claim 2, wherein the received user data is
encrypted by the AMF.
4. The method of claim 1, wherein the communicating the user data
comprises: receiving the user data from the DN as the SM payload
received from the SMF.
5. The method of claim 4, wherein the received user data is
encrypted by the AMF.
6. The method of claim 1, wherein the communicating the user data
comprises: transmitting the user data to the SMF as the SM payload
for transport to the AF.
7. The method of claim 1, wherein the communicating the user data
comprises: transmitting the user data to the SMF as the SM payload
for transport to the DN.
8. The method of claim 1, further comprising: receiving an
indication of stored user data for the user equipment at the SMF;
transmitting an second indication that the UE is ready to receive
the stored user data; and receiving the user data from the SMF in
response to the second indication.
9. The method of claim 1, wherein the user data comprises encrypted
data that is encrypted based on an SMF encryption key, wherein the
SMF encryption key comprises a shared key between the user
equipment and the SMF.
10. An apparatus for wireless communication at a user equipment
(UE), the apparatus comprising: a memory; and at least one
processor coupled to the memory and configured to: establish a
session with a session management function (SMF) for communication
of user data below a size threshold; and communicate the user data
with at least one of an Application Function (AF) or a Data Network
(DN), wherein the user data is communicated with the SMF for
transport via an Access and Mobility Management Function (AMF) as a
Session Management (SM) payload over a Non Access Stratum (NAS)
protocol.
11. The apparatus of claim 10, wherein to communicate the user
data, the at least one processor is further configured to: receive
the user data from the AF as the SM payload received from the
SMF.
12. The apparatus of claim 11, wherein the received user data is
encrypted by the AMF.
13. The apparatus of claim 10, wherein to communicate the user
data, the at least one processor is further configured to: receive
the user data from the DN as the SM payload received from the
SMF.
14. The apparatus of claim 13, wherein the received user data is
encrypted by the AMF.
15. The apparatus of claim 10, wherein to communicate the user
data, the at least one processor is further configured to: transmit
the user data to the SMF as the SM payload for transport to the
AF.
16. The apparatus of claim 10, wherein to communicate the user
data, the at least one processor is further configured to: transmit
the user data to the SMF as the SM payload for transport to the
DN.
17. The apparatus of claim 10, wherein the at least one processor
is further configured to: receive an indication of stored user data
for the user equipment at the SMF; transmit an second indication
that the UE is ready to receive the stored user data; and receive
the user data from the SMF in response to the second
indication.
18. The apparatus of claim 10, wherein the user data comprises
encrypted data that is encrypted based on an SMF encryption key,
wherein the SMF encryption key comprises a shared key between the
user equipment and the SMF.
19. An apparatus for wireless communication at a user equipment
(UE), comprising: means for establishing a session with a session
management function (SMF) for communication of user data below a
size threshold; and means for communicating the user data with at
least one of an Application Function (AF) or a Data Network (DN),
wherein the user data is communicated with the SMF for transport
via an Access and Mobility Management Function (AMF) as a Session
Management (SM) payload over a Non Access Stratum (NAS)
protocol.
20. The apparatus of claim 19, wherein the communicating the user
data comprises: means for receiving the user data from the AF as
the SM payload received from the SMF.
21. The apparatus of claim 20, wherein the received user data is
encrypted by the AMF.
22. The apparatus of claim 19, wherein the communicating the user
data comprises: means for receiving the user data from the DN as
the SM payload received from the SMF.
23. The apparatus of claim 22, wherein the received user data is
encrypted by the AMF.
24. The apparatus of claim 19, wherein the communicating the user
data comprises: means for transmitting the user data to the SMF as
the SM payload for transport to the AF.
25. The apparatus of claim 19, wherein the communicating the user
data comprises: means for transmitting the user data to the SMF as
the SM payload for transport to the DN.
26. The apparatus of claim 19, further comprising: means for
receiving an indication of stored user data for the user equipment
at the SMF; means for transmitting an second indication that the UE
is ready to receive the stored user data; and means for receiving
the user data from the SMF in response to the second
indication.
27. The apparatus of claim 19, wherein the user data comprises
encrypted data that is encrypted based on an SMF encryption key,
wherein the SMF encryption key comprises a shared key between the
user equipment and the SMF.
28. A non-transitory computer-readable medium storing computer
executable code for wireless communication at a user equipment, the
code when executed by a processor causes the processor to:
establish a session with a session management function (SMF) for
communication of user data below a size threshold; and communicate
the user data with at least one of an Application Function (AF) or
a Data Network (DN), wherein the user data is communicated with the
SMF for transport via an Access and Mobility Management Function
(AMF) as a Session Management (SM) payload over a Non Access
Stratum (NAS) protocol.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent
application Ser. No. 16/128,127, entitled "CONTROL PLANE BASED
SMALL DATA SERVICE" and filed on Sep. 11, 2018, which claims the
benefit of U.S. Provisional Application Ser. No. 62/560,097,
entitled "Control Plane Based Small Data Service" and filed on Sep.
18, 2017, the entire contents which are expressly incorporated by
reference herein in their entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates generally to communication
systems, and more particularly, to data delivery over a core
network.
INTRODUCTION
[0003] Wireless communication systems are widely deployed to
provide various telecommunication services such as telephony,
video, data, messaging, and broadcasts. Typical wireless
communication systems may employ multiple-access technologies
capable of supporting communication with multiple users by sharing
available system resources. Examples of such multiple-access
technologies include code division multiple access (CDMA) systems,
time division multiple access (TDMA) systems, frequency division
multiple access (FDMA) systems, orthogonal frequency division
multiple access (OFDMA) systems, single-carrier frequency division
multiple access (SC-FDMA) systems, and time division synchronous
code division multiple access (TD-SCDMA) systems.
[0004] These multiple access technologies have been adopted 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
telecommunication standard is 5G New Radio (NR). 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 (IoT)), and other requirements. Some
aspects of 5G NR may be based on the 4G Long Term Evolution (LTE)
standard. There exists a need for further improvements in 5G NR
technology. These improvements may also be applicable to other
multi-access technologies and the telecommunication standards that
employ these technologies.
[0005] A focus of the traditional LTE design relates to the
improvement of spectral efficiency, ubiquitous coverage, and
enhanced quality of service (QoS) support, etc. Current LTE system
down link (DL) and uplink (UL) link budgets may be designed for
coverage of high end devices, such as state-of-the-art smartphones
and tablets. However, it may be desirable to support low cost low
rate devices as well. Such communication may involve a reduction in
a maximum bandwidth, e.g., a narrowband bandwidth, use of a single
receive radio frequency (RF) chain, a reduction in peak rate, a
reduction in transmit power, the performance of half duplex
operation, etc. One example of such narrowband wireless
communication is Narrowband-Internet of Things (NB-IoT), which may
be limited to a single RB of system bandwidth, e.g., 180 kHz.
Another example of narrowband wireless communication is enhanced
machine type communication (eMTC), which may be limited to six RBs
of system bandwidth.
[0006] Narrowband wireless communication involves unique challenges
due to the limited frequency dimension of the narrow band.
Additionally, low power operation may be very important for such
low complexity devices.
SUMMARY
[0007] The following presents a simplified summary of one or more
aspects in order to provide a basic understanding of such aspects.
This summary is not an extensive overview of all contemplated
aspects, and is intended to neither identify key or critical
elements of all aspects nor delineate the scope of any or all
aspects. Its sole purpose is to present some concepts of one or
more aspects in a simplified form as a prelude to the more detailed
description that is presented later.
[0008] In Cellular Internet of Things (CIoT) small amounts of data
may need to be transferred via a core network to a User Equipment
(UE). This may include infrequent small data transfers and/or
frequent small data transfers.
[0009] Aspects presented herein provide for transport of small data
to the UE via a control plane of the core network in a manner that
may reduce connection set up requirements for the UE and the
network in order to communicate such small data to the UE. The data
may be transported as a Session Management (SM) payload from a
Small Data Capable Session Management Function (SDC-SMF) at the
core network. At a core network, data ingress for Non-IP Data
Delivery (NIDD) may use a T8 reference point. The SDC-SMF may
terminate a T8 interface by which an Application Function (AF)
introduces data into the core network. In another example, a
Network Exposure Function (NEF) may terminate a T8 interface with
an AF. The SDC-SMF may be configured to store and forward small
data towards a UE. For example, the SDC-SMF may be configured to
buffer small data while a UE is in an idle mode and to forward the
small data toward the UE when the UE is awake. The SDC-SMF may
enable the SMF to manage Quality of Service (QoS) for a small data
stream. The SDC-SMF may be configured to perform Internet Protocol
(IP) compression, e.g., IP header compression, for small data IP
streams. The SDC-SMF may also encrypt data with SMF specific
encryption keys. The SDC-SMF may also protect the integrity of the
data with SMF specific integrity-protection keys. The SMF specific
encryption and/or integrity protection keys may be the shared keys
between the UE and the SMF.
[0010] In an aspect of the disclosure, a method, a
computer-readable medium, and an apparatus are provided. The
apparatus receives data from at least one of an AF, a DN, or a UE.
The apparatus processes the data at an SMF for transport with a low
overhead as a session management payload over an NAS protocol. The
data may be received from the AF or the DN, and the apparatus may
transport the data from the SMF to the user equipment based on a SM
payload. The data may be received from the UE as an SM payload, and
the apparatus may transport the data to the AF or the DN.
[0011] In another aspect, a method, a computer-readable medium, and
an apparatus are provided for wireless communication at a user
equipment. The apparatus establishes a session with an SMF and
communicates data with at least one of an SF or a DN, wherein the
data is communicated with the SMF for transport with a low overhead
as SM payload over a NAS protocol. For example the apparatus may
receive the data from the AF or the DN based on the SM payload
received from the SMF. In another example, the apparatus may
transmit the data to the SMF based on a SM payload for transport to
the AF or the DN.
[0012] To the accomplishment of the foregoing and related ends, the
one or more aspects comprise the features hereinafter fully
described and particularly pointed out in the claims. The following
description and the annexed drawings set forth in detail certain
illustrative features of the one or more aspects. These features
are indicative, however, of but a few of the various ways in which
the principles of various aspects may be employed, and this
description is intended to include all such aspects and their
equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a diagram illustrating an example of a wireless
communications system and an access network.
[0014] FIG. 2 illustrates an example slot structure for UL centric
slots and DL centric slots.
[0015] FIG. 3 is a diagram illustrating an example of a base
station and user equipment (UE) in an access network.
[0016] FIG. 4 is a diagram illustrating an SDC-SMF.
[0017] FIG. 5 is an example network architecture having a data
delivery path comprising an SDC-SMF.
[0018] FIG. 6 illustrates an example roaming network architecture
having a data delivery path comprising an SDC-SMF.
[0019] FIG. 7 illustrates an example Non-Internet Protocol Data
Delivery (NIDD) protocol stack for data delivery through an
SDC-SMF.
[0020] FIG. 8 illustrates an example Internet Protocol Data
Delivery (IPDD) protocol stack for data delivery through an
SDC-SMF.
[0021] FIG. 9 illustrates an example communication flow for NIDD
through an SDC-SMF.
[0022] FIG. 10 illustrates an example communication flow for NIDD
connection set-up
[0023] FIG. 11 illustrates an example communication flow for Mobile
Terminated Data Delivery.
[0024] FIG. 12 illustrates an example roaming network architecture
having a data delivery path comprising an SDC-SMF.
[0025] FIG. 13 is a flowchart of a method of wireless
communication.
[0026] FIG. 14 is a conceptual data flow diagram illustrating the
data flow between different means/components in an exemplary
apparatus.
[0027] FIG. 15 is a diagram illustrating an example of a hardware
implementation for an apparatus employing a processing system.
[0028] FIG. 16 is a flowchart of a method of wireless
communication.
[0029] FIG. 17 is a conceptual data flow diagram illustrating the
data flow between different means/components in an exemplary
apparatus.
[0030] FIG. 18 is a diagram illustrating an example of a hardware
implementation for an apparatus employing a processing system.
DETAILED DESCRIPTION
[0031] The detailed description set forth below in connection with
the appended drawings is intended as a description of various
configurations and is not intended to represent the only
configurations in which the concepts described herein may be
practiced. The detailed description includes specific details for
the purpose of providing a thorough understanding of various
concepts. However, it will be apparent to those skilled in the art
that these concepts may be practiced without these specific
details. In some instances, well known structures and components
are shown in block diagram form in order to avoid obscuring such
concepts.
[0032] Several aspects of telecommunication systems will now be
presented with reference to various apparatus and methods. These
apparatus and methods will be described in the following detailed
description and illustrated in the accompanying drawings by various
blocks, components, circuits, processes, algorithms, etc.
(collectively referred to as "elements"). These elements may be
implemented using electronic hardware, computer software, or any
combination thereof. Whether such elements are implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system.
[0033] By way of example, an element, or any portion of an element,
or any combination of elements may be implemented as a "processing
system" that includes one or more processors. Examples of
processors include microprocessors, microcontrollers, graphics
processing units (GPUs), central processing units (CPUs),
application processors, digital signal processors (DSPs), reduced
instruction set computing (RISC) processors, systems on a chip
(SoC), baseband processors, field programmable gate arrays (FPGAs),
programmable logic devices (PLDs), state machines, gated logic,
discrete hardware circuits, and other suitable hardware configured
to perform the various functionality described throughout this
disclosure. One or more processors in the processing system may
execute software. Software shall be construed broadly to mean
instructions, instruction sets, code, code segments, program code,
programs, subprograms, software components, applications, software
applications, software packages, routines, subroutines, objects,
executables, threads of execution, procedures, functions, etc.,
whether referred to as software, firmware, middleware, microcode,
hardware description language, or otherwise.
[0034] Accordingly, in one or more example embodiments, the
functions described may be implemented in hardware, software, or
any combination thereof. If implemented in software, the functions
may be stored on or encoded as one or more instructions or code on
a computer-readable medium. Computer-readable media includes
computer storage media. Storage media may be any available media
that can be accessed by a computer. By way of example, and not
limitation, such computer-readable media can comprise a
random-access memory (RAM), a read-only memory (ROM), an
electrically erasable programmable ROM (EEPROM), optical disk
storage, magnetic disk storage, other magnetic storage devices,
combinations of the aforementioned types of computer-readable
media, or any other medium that can be used to store computer
executable code in the form of instructions or data structures that
can be accessed by a computer.
[0035] FIG. 1 is a diagram illustrating an example of a wireless
communications system and an access network 100. The wireless
communications system (also referred to as a wireless wide area
network (WWAN)) includes base stations 102, UEs 104, and an Evolved
Packet Core (EPC) 160. The base stations 102 may include macro
cells (high power cellular base station) and/or small cells (low
power cellular base station). The macro cells include base
stations. The small cells include femtocells, picocells, and
microcells.
[0036] The base stations 102 (collectively referred to as Evolved
Universal Mobile Telecommunications System (UMTS) Terrestrial Radio
Access Network (E-UTRAN)) interface with the EPC 160 through
backhaul links 132 (e.g., S1 interface). In addition to other
functions, the base stations 102 may perform one or more of the
following functions: transfer of user data, radio channel ciphering
and deciphering, integrity protection, header compression, mobility
control functions (e.g., handover, dual connectivity), inter-cell
interference coordination, connection setup and release, load
balancing, distribution for non-access stratum (NAS) messages, NAS
node selection, synchronization, radio access network (RAN)
sharing, multimedia broadcast multicast service (MBMS), subscriber
and equipment trace, RAN information management (RIM), paging,
positioning, and delivery of warning messages. The base stations
102 may communicate directly or indirectly (e.g., through the EPC
160) with each other over backhaul links 134 (e.g., X2 interface).
The backhaul links 134 may be wired or wireless.
[0037] The base stations 102 may wirelessly communicate with the
UEs 104. Each of the base stations 102 may provide communication
coverage for a respective geographic coverage area 110. There may
be overlapping geographic coverage areas 110. For example, the
small cell 102' may have a coverage area 110' that overlaps the
coverage area 110 of one or more macro base stations 102. A network
that includes both small cell and macro cells may be known as a
heterogeneous network. A heterogeneous network may also include
Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a
restricted group known as a closed subscriber group (CSG). The
communication links 120 between the base stations 102 and the UEs
104 may include uplink (UL) (also referred to as reverse link)
transmissions from a UE 104 to a base station 102 and/or downlink
(DL) (also referred to as forward link) transmissions from a base
station 102 to a UE 104. The communication links 120 may use
multiple-input and multiple-output (MIMO) antenna technology,
including spatial multiplexing, beamforming, and/or transmit
diversity. The communication links may be through one or more
carriers. The base stations 102/UEs 104 may use spectrum up to Y
MHz (e.g., 5, 10, 15, 20, 100 MHz) bandwidth per carrier allocated
in a carrier aggregation of up to a total of Yx MHz (x component
carriers) used for transmission in each direction. The carriers may
or may not be adjacent to each other. Allocation of carriers may be
asymmetric with respect to DL and UL (e.g., more or less carriers
may be allocated for DL than for UL). The component carriers may
include a primary component carrier and one or more secondary
component carriers. A primary component carrier may be referred to
as a primary cell (PCell) and a secondary component carrier may be
referred to as a secondary cell (SCell).
[0038] Certain UEs 104 may communicate with each other using
device-to-device (D2D) communication link 192. The D2D
communication link 192 may use the DL/UL WWAN spectrum. The D2D
communication link 192 may use one or more sidelink channels, such
as a physical sidelink broadcast channel (PSBCH), a physical
sidelink discovery channel (PSDCH), a physical sidelink shared
channel (PSSCH), and a physical sidelink control channel (PSCCH).
D2D communication may be through a variety of wireless D2D
communications systems, such as for example, FlashLinQ, WiMedia,
Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or
NR.
[0039] The wireless communications system may further include a
Wi-Fi access point (AP) 150 in communication with Wi-Fi stations
(STAs) 152 via communication links 154 in a 5 GHz unlicensed
frequency spectrum. When communicating in an unlicensed frequency
spectrum, the STAs 152/AP 150 may perform a clear channel
assessment (CCA) prior to communicating in order to determine
whether the channel is available.
[0040] The small cell 102' may operate in a licensed and/or an
unlicensed frequency spectrum. When operating in an unlicensed
frequency spectrum, the small cell 102' may employ NR and use the
same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP
150. The small cell 102', employing NR in an unlicensed frequency
spectrum, may boost coverage to and/or increase capacity of the
access network.
[0041] The gNodeB (gNB) 180 may operate in millimeter wave (mmW)
frequencies and/or near mmW frequencies in communication with the
UE 104. When the gNB 180 operates in mmW or near mmW frequencies,
the gNB 180 may be referred to as an mmW base station. Extremely
high frequency (EHF) is part of the RF in the electromagnetic
spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength
between 1 millimeter and 10 millimeters. Radio waves in the band
may be referred to as a millimeter wave. Near mmW may extend down
to a frequency of 3 GHz with a wavelength of 100 millimeters. The
super high frequency (SHF) band extends between 3 GHz and 30 GHz,
also referred to as centimeter wave. Communications using the
mmW/near mmW radio frequency band has extremely high path loss and
a short range. The mmW base station 180 may utilize beamforming 184
with the UE 104 to compensate for the extremely high path loss and
short range.
[0042] The EPC 160 may include a Mobility Management Entity (MME)
162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast
Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service
Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172.
The MME 162 may be in communication with a Home Subscriber Server
(HSS) 174. The MME 162 is the control node that processes the
signaling between the UEs 104 and the EPC 160. Generally, the MME
162 provides bearer and connection management. All user Internet
protocol (IP) packets are transferred through the Serving Gateway
166, which itself is connected to the PDN Gateway 172. The PDN
Gateway 172 provides UE IP address allocation as well as other
functions. The PDN Gateway 172 and the BM-SC 170 are connected to
the IP Services 176. The IP Services 176 may include the Internet,
an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming
Service, and/or other IP services. The BM-SC 170 may provide
functions for MBMS user service provisioning and delivery. The
BM-SC 170 may serve as an entry point for content provider MBMS
transmission, may be used to authorize and initiate MBMS Bearer
Services within a public land mobile network (PLMN), and may be
used to schedule MBMS transmissions. The MBMS Gateway 168 may be
used to distribute MBMS traffic to the base stations 102 belonging
to a Multicast Broadcast Single Frequency Network (MBSFN) area
broadcasting a particular service, and may be responsible for
session management (start/stop) and for collecting eMBMS related
charging information.
[0043] The base station may also be referred to as a gNB, Node B,
evolved Node B (eNB), an access point, a base transceiver station,
a radio base station, a radio transceiver, a transceiver function,
a basic service set (BSS), an extended service set (ESS), or some
other suitable terminology. The base station 102 provides an access
point to the EPC 160 for a UE 104. Examples of UEs 104 include a
cellular phone, a smart phone, a session initiation protocol (SIP)
phone, a laptop, a personal digital assistant (PDA), a satellite
radio, a global positioning system, a multimedia device, a video
device, a digital audio player (e.g., MP3 player), a camera, a game
console, a tablet, a smart device, a wearable device, a vehicle, an
electric meter, a gas pump, a large or small kitchen appliance, a
healthcare device, an implant, a display, or any other similar
functioning device. Some of the UEs 104 may be referred to as IoT
devices (e.g., parking meter, gas pump, toaster, vehicles, heart
monitor, etc.). The UE 104 may also be referred to as a station, a
mobile station, a subscriber station, a mobile unit, a subscriber
unit, a wireless unit, a remote unit, a mobile device, a wireless
device, a wireless communications device, a remote device, a mobile
subscriber station, an access terminal, a mobile terminal, a
wireless terminal, a remote terminal, a handset, a user agent, a
mobile client, a client, or some other suitable terminology.
[0044] Referring again to FIG. 1, in certain aspects, a core
network, e.g., network 160, may include an SMF capable of
processing and communicating small data between UE 104 and an AF or
DN external to the network (e.g., SDC-SMF 198), such as described
in connection with FIGS. 4-18. In other aspects, UE 104 may
comprise a small data component 199 configured to communicate small
data with an AF or DN based on an SM payload, as described in
connection with FIGS. 4-18.
[0045] FIG. 2 illustrates an example slot structure comprising DL
centric slots and UL centric slots. In NR, a slot may have a
duration of 0.5 ms, 0.25 ms, etc., and each slot may have 7 or 14
symbols. A resource grid may be used to represent the time slots,
each time slot including one or more time concurrent resource
blocks (RBs) (also referred to as physical RBs (PRBs)). The
resource blocks for the resource grid may be further divided into
multiple resource elements (REs). The number of bits carried by
each RE depends on the modulation scheme.
[0046] A slot may be DL only or UL only, and may also be DL centric
or UL centric. FIG. 2 illustrates an example DL centric slot. The
DL centric slot may comprise a DL control region 202, e.g., in
which in which physical downlink control channel (PDCCH) is
transmitted. Some of the REs of the DL centric slot may carry DL
reference (pilot) signals (DL-RS) for channel estimation at the UE.
The DL-RS may include cell-specific reference signals (CRS) (also
sometimes called common RS), UE-specific reference signals (UE-RS),
and channel state information reference signals (CSI-RS).
[0047] A physical broadcast channel (PBCH) may carry a master
information block (MIB). The MIB provides a number of RBs in the DL
system bandwidth, a PHICH configuration, and a system frame number
(SFN). The DL centric slot may comprise a DL data region 204, e.g.,
in which a physical downlink shared channel (PDSCH) carries user
data, broadcast system information not transmitted through the PBCH
such as system information blocks (SIBs), and paging messages.
[0048] The DL centric slot may also comprise a common UL burst
region (ULCB) 206 in which UEs may send UL control channel
information or other time sensitive or otherwise critical UL
transmissions.
[0049] For example, the UE may additionally transmit sounding
reference signals (SRS). The SRS may be used by an eNB for channel
quality estimation to enable frequency-dependent scheduling on the
UL. A physical random access channel (PRACH) may be included within
one or more slots within a slot structure based on the PRACH
configuration. The PRACH allows the UE to perform initial system
access and achieve UL synchronization. Additionally, the common UL
burst 206 may comprise a physical uplink control channel (PUCCH)
that carries uplink control information (UCI), such as scheduling
requests, a channel quality indicator (CQI), a precoding matrix
indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK
feedback.
[0050] Similar to the DL centric slot, the UL centric slot may
comprise a DL control region 208, e.g., for PDCCH transmissions.
The DL control region 202, 208 may comprise a limited number of
symbols at the beginning of a slot. The UL centric slot may
comprise an UL data region 210, e.g., for the transmission of a
Physical Uplink Shared Channel (PUSCH) that carries data, and may
additionally be used to carry a buffer status report (BSR), a power
headroom report (PHR), and/or UCI. The UL data region 210 may be
referred to as a UL regular burst (ULRB) region. The UL centric
slot may also comprise a common UL burst region (ULCB) 212 similar
to that of the DL based slot 206.
[0051] The UL centric slot may comprise a guard band between the UL
data region 210 and the ULCB 212. For example, the guard band may
be based on the eNB's capabilities and used to reduce interference
when the UL data region 210 and the ULCB have different
numerologies (symbol periods, slot lengths, etc.). The DL control
region 202, 208 may comprise a limited number of symbols at the
beginning of a slot and the ULCB region may comprise one or two
symbols at the end of the slot, for both the DL centric and the UL
centric slots. Resource management of PUSCH or PUCCH transmissions
in the ULRB may be similar to that PUSCH or PUCCH for LTE. However,
where LTE may be primarily driven by a SC-FDM waveform, NR may be
based on an SC-FDM or OFDM waveform in the ULRB 210.
[0052] FIG. 3 is a block diagram of a base station 310 in
communication with a UE 350 in an access network. In the DL, IP
packets from the EPC 160 may be provided to a controller/processor
375. The controller/processor 375 implements layer 3 and layer 2
functionality. Layer 3 includes a radio resource control (RRC)
layer, and layer 2 includes a packet data convergence protocol
(PDCP) layer, a radio link control (RLC) layer, and a medium access
control (MAC) layer. The controller/processor 375 provides RRC
layer functionality associated with broadcasting of system
information (e.g., MIB, SIBs), RRC connection control (e.g., RRC
connection paging, RRC connection establishment, RRC connection
modification, and RRC connection release), inter radio access
technology (RAT) mobility, and measurement configuration for UE
measurement reporting; PDCP layer functionality associated with
header compression/decompression, security (ciphering, deciphering,
integrity protection, integrity verification), and handover support
functions; RLC layer functionality associated with the transfer of
upper layer packet data units (PDUs), error correction through ARQ,
concatenation, segmentation, and reassembly of RLC service data
units (SDUs), re-segmentation of RLC data PDUs, and reordering of
RLC data PDUs; and MAC layer functionality associated with mapping
between logical channels and transport channels, multiplexing of
MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs
from TBs, scheduling information reporting, error correction
through HARQ, priority handling, and logical channel
prioritization.
[0053] The transmit (TX) processor 316 and the receive (RX)
processor 370 implement layer 1 functionality associated with
various signal processing functions. Layer 1, which includes a
physical (PHY) layer, may include error detection on the transport
channels, forward error correction (FEC) coding/decoding of the
transport channels, interleaving, rate matching, mapping onto
physical channels, modulation/demodulation of physical channels,
and MIMO antenna processing. The TX processor 316 handles mapping
to signal constellations based on various modulation schemes (e.g.,
binary phase-shift keying (BPSK), quadrature phase-shift keying
(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude
modulation (M-QAM)). The coded and modulated symbols may then be
split into parallel streams. Each stream may then be mapped to an
OFDM subcarrier, multiplexed with a reference signal (e.g., pilot)
in the time and/or frequency domain, and then combined together
using an Inverse Fast Fourier Transform (IFFT) to produce a
physical channel carrying a time domain OFDM symbol stream. The
OFDM stream is spatially precoded to produce multiple spatial
streams. Channel estimates from a channel estimator 374 may be used
to determine the coding and modulation scheme, as well as for
spatial processing. The channel estimate may be derived from a
reference signal and/or channel condition feedback transmitted by
the UE 350. Each spatial stream may then be provided to a different
antenna 320 via a separate transmitter 318TX. Each transmitter
318TX may modulate an RF carrier with a respective spatial stream
for transmission.
[0054] At the UE 350, each receiver 354RX receives a signal through
its respective antenna 352. Each receiver 354RX recovers
information modulated onto an RF carrier and provides the
information to the receive (RX) processor 356. The TX processor 368
and the RX processor 356 implement layer 1 functionality associated
with various signal processing functions. The RX processor 356 may
perform spatial processing on the information to recover any
spatial streams destined for the UE 350. If multiple spatial
streams are destined for the UE 350, they may be combined by the RX
processor 356 into a single OFDM symbol stream. The RX processor
356 then converts the OFDM symbol stream from the time-domain to
the frequency domain using a Fast Fourier Transform (FFT). The
frequency domain signal comprises a separate OFDM symbol stream for
each subcarrier of the OFDM signal. The symbols on each subcarrier,
and the reference signal, are recovered and demodulated by
determining the most likely signal constellation points transmitted
by the base station 310. These soft decisions may be based on
channel estimates computed by the channel estimator 358. The soft
decisions are then decoded and deinterleaved to recover the data
and control signals that were originally transmitted by the base
station 310 on the physical channel. The data and control signals
are then provided to the controller/processor 359, which implements
layer 3 and layer 2 functionality.
[0055] The controller/processor 359 can be associated with a memory
360 that stores program codes and data. The memory 360 may be
referred to as a computer-readable medium. In the UL, the
controller/processor 359 provides demultiplexing between transport
and logical channels, packet reassembly, deciphering, header
decompression, and control signal processing to recover IP packets
from the EPC 160. The controller/processor 359 is also responsible
for error detection using an ACK and/or NACK protocol to support
HARQ operations.
[0056] Similar to the functionality described in connection with
the DL transmission by the base station 310, the
controller/processor 359 provides RRC layer functionality
associated with system information (e.g., MIB, SIB s) acquisition,
RRC connections, and measurement reporting; PDCP layer
functionality associated with header compression/decompression, and
security (ciphering, deciphering, integrity protection, integrity
verification); RLC layer functionality associated with the transfer
of upper layer PDUs, error correction through ARQ, concatenation,
segmentation, and reassembly of RLC SDUs, re-segmentation of RLC
data PDUs, and reordering of RLC data PDUs; and MAC layer
functionality associated with mapping between logical channels and
transport channels, multiplexing of MAC SDUs onto TBs,
demultiplexing of MAC SDUs from TBs, scheduling information
reporting, error correction through HARQ, priority handling, and
logical channel prioritization.
[0057] Channel estimates derived by a channel estimator 358 from a
reference signal or feedback transmitted by the base station 310
may be used by the TX processor 368 to select the appropriate
coding and modulation schemes, and to facilitate spatial
processing. The spatial streams generated by the TX processor 368
may be provided to different antenna 352 via separate transmitters
354TX. Each transmitter 354TX may modulate an RF carrier with a
respective spatial stream for transmission.
[0058] The UL transmission is processed at the base station 310 in
a manner similar to that described in connection with the receiver
function at the UE 350. Each receiver 318RX receives a signal
through its respective antenna 320. Each receiver 318RX recovers
information modulated onto an RF carrier and provides the
information to a RX processor 370.
[0059] The controller/processor 375 can be associated with a memory
376 that stores program codes and data. The memory 376 may be
referred to as a computer-readable medium. In the UL, the
controller/processor 375 provides demultiplexing between transport
and logical channels, packet reassembly, deciphering, header
decompression, control signal processing to recover IP packets from
the UE 350. IP packets from the controller/processor 375 may be
provided to the EPC 160. The controller/processor 375 is also
responsible for error detection using an ACK and/or NACK protocol
to support HARQ operations.
[0060] It may be desirable to support low cost low rate devices.
Such communication may involve a reduction in a maximum bandwidth,
e.g., a narrowband bandwidth, use of a single receive radio
frequency (RF) chain, a reduction in peak rate, a reduction in
transmit power, the performance of half duplex operation, etc. One
example of such narrowband wireless communication is
Narrowband-Internet of Things (NB-IoT), which may be limited to a
single RB of system bandwidth, e.g., 180 kHz. Another example of
narrowband wireless communication is enhanced machine type
communication (eMTC), which may be limited to six RBs of system
bandwidth.
[0061] Narrowband wireless communication involves unique challenges
due to the limited frequency dimension of the narrow band.
Additionally, low power operation may be very important for such
low complexity devices.
[0062] In Cellular Internet of Things (CIoT) small amounts of data
may need to be transferred via a core network to a user equipment.
This may include infrequent small user data transfers and/or
frequent small user data transfers. Small user data may comprise
small amounts of data having a size below a threshold. Such data
may comprise user data in contrast to control or measurement
communication. Small user data may comprise, e.g., a data stream
having relatively infrequent and/or short lived sporadic burst
transmissions of data for which the overhead requirements of a
conventional link set up protocol would be large relative to the
amount of data to be conveyed. In one example, small data may have
a size below 100 bytes and/or may have a data rate below 100 kbps.
For example, an electricity meter or a water meter may monitor and
report data about electricity usage or water usage. The meters may
periodically transmit small amounts of data to a network, e.g.,
reporting the monitored electrical or water information. In another
example, the small data may comprise information from collected at
a sensor. The data comprises user data rather than control
information or control measurements from a UE.
[0063] In an example, the small user data may be a 50 byte packet.
If the 50 byte packet is handled in the same manner as larger data
packets, then a significant amount of communication must be
performed to establish a connection, open radio bearers, establish
security, etc. in preparation to send the data. The communication
required in preparation to send the user data to a UE may include
hundreds of bytes of data, whereas the user data itself may be only
50 bytes or less. The large overhead requirement in comparison to
the small user data places a significant burden on both the core
network and the UE. An AF, a DN, or a UE may send small data
messages in a periodic manner, e.g., once every hour. The overhead
requirement grows with the periodic communication of such small
data, because the overhead signaling must be performed for each
periodic communication. Furthermore, the network may support a
large number of devices that communicate small data, thereby
amplifying the overhead burden.
[0064] Both a UE and a network may benefit from leveraging an idle
mode as much as possible. Additional benefits may be derived
through a reduction in connection set up requirements for small
data transfers. It may also be helpful to minimize, or otherwise
reduce, context storage requirements at RAN nodes.
[0065] At a core network, data ingress for Non-IP Data Delivery
(NIDD) may use a T8 reference point, in one example. This may
minimize impact to service due to inter-RAT or Inter-Core Network
(Inter-CN) mobility by the UE.
[0066] In order to provide such benefits to the UE and the network,
small data frames may be carried over a control plane. As described
above, small amounts of data may be transmitted in a periodic or
infrequent manner. As one example, a sensor may transmit
measurement data in an infrequent or periodic manner. Small data
may comprise data that meets a size threshold, such as being below
a size threshold. In one example, the size threshold may be, e.g.,
64 octet. Thus, data that is less than 64 octet may be carried over
the control plane, as presented herein, in a manner that reduces
the overhead burden to communicate the data. In another example, as
described above, a threshold for small data may comprise 100 bytes
and/or a data rate of 100 kbps. In this example, small data having
a size below 100 bytes and/or having a data rate below 100 kbps may
be carried over the control plane. If the data is larger than the
size threshold for small data, e.g., the data may be communicated
in another manner, e.g., using the normal signaling overhead. The
examples of 64 octet, 100 bytes, and/or 100 kbps are merely
examples of a size threshold for small data. The size threshold for
data to be transported as small data over the control plane may
also be set at a different size.
[0067] Architectural changes may be made to configure an SMF and
other control plane entities to support small data transport. FIG.
4 illustrates an enhanced SMF 402 configured to include a small
data delivery service function (SDDSF) 404. The Small Data Capable
SMF (SDC-SMF) enables small data transfer over a NAS. The SDDSF may
provide enhanced capabilities to the SMF. In one example, the SMF
may terminate a T8 interface 406 for small data, e.g., from an AF.
As illustrated in FIG. 5, in other examples, the NEF may terminate
the T8 interface from the AF, and may have an interface, e.g., an
Nsm interface, to the SMF. The SDDSF may enable the SMF to store
and forward small data towards a UE. For example, the SMF may be
configured to buffer small data while a UE is in an idle mode and
to forward the small data toward the UE when the UE is awake. The
SDDSF may enable the SMF to manage QoS for a small data stream. The
SDDSF may be configured to perform IP header compression, e.g., IP
header compression, for small data IP streams. The SDDSF may also
encrypt data with SMF specific encryption keys. These encryption
keys may be provided by an AF, e.g. rather than from a UE network
service subscription.
[0068] FIG. 5 illustrates an example network architecture 500
having a data delivery path that comprises an SDC-SMF 502. The
network architecture 500 may comprise a 5G NR network having a
control plane and a user plane. As illustrated in FIG. 5, Mobile
Terminated (MT) NIDD data 501 may enter the core network, e.g.,
from an AF 504 external to the network, and may be processed at a
SDC-SMF 502 for transport to the UE 512 over the control plane. In
one example, the data may enter the core network through a T8
interface from the AF 504 that terminates at the SDC-SMF 502. Thus,
SDC-SMF may provide an ingress point for data from the AF. As
illustrated in FIG. 5, the NEF 514 may also terminate a T8
interface from the AF 504 and may have an interface, e.g., an Nsm
interface, to the SDC-SMF. Although only a single AF 504 is
illustrated in FIG. 5, any number of AFs may transport data to
various user equipment via the core network. An example set up
procedure linking the AF 504 to an SDC-SMF 502 is illustrated in
FIGS. 9 and 10, e.g., via the T8 interface 511 directly from AF 504
to SDC-SMF 502 or indirectly via the T8 interface 513 from the AF
504 to the NEF 514 that then connects via interface 515 to the
SDC-SMF 502. Mobile Terminated (MT) IP Data Delivery (IPDD) data
503 may enter the core network via a Data Network (DN) 506, e.g.,
via an N6 interface. The User Plane Function (UPF) 508 that
receives the IPDD 503 may forward the data 505 to the SDC-SMF 502,
e.g., via an N4 interface 519. IP compression, e.g., IP header
compression, may be performed at the SDC-SMF 502. Thus, the SDC-SMF
502 may receive data from the AF 504 or the DN 506 and may process
the data for transport to the UE 512. The data 501, 505 may be
placed in an NAS SM message payload 507 and sent to the AMF 510 via
an interface 517, whether the data is NIDD 501 coming into the core
network from an AF 504 or the data is IPDD 503 coming into the core
network from a DN 506. The data 509 may then be forwarded as a NAS
SM message payload to the UE 512 from the Core Access and Mobility
Management Function (AMF) 510. FIG. 5 also illustrates example
interfaces between a Network Exposure Function (NEF) 514 and the
SDC-SFM 502 and AF 504. Thus, as illustrated in FIG. 5, the NEF 514
may provide a T8 termination for data entering the core network
from AF 504 and may have an interface 515 that connects to SDC-SMF,
which processes the data to be sent to UE 512 as a NAS SM payload
via AMF 510. As well, an interface 503 is illustrated between the
UPF 508 and the UE 512 and a Radio Access Network (RAN) 516.
[0069] The SDC-SMF 502 may also protect the integrity of the data
with SMF specific integrity-protection keys. The SMF specific
encryption and/or integrity protection keys are the shared keys
between the UE 512 and the SDC-SMF 502.
[0070] Although this example has been described for data received
from an AF 504 or DN 506 and transmitted to a UE 512, the SDC-SMF
502 may similarly receive small data from UE 512, e.g., as an SM
payload. FIG. 10 illustrates an example communication flow showing
both uplink and downlink small data transmissions. The SDC-SMF 502
may process the SM payload received from the UE 512, e.g., via AMF
510, to obtain the data and to provide the data to the AF 504 or
the DN 506. In this example, the SDC-SMF 502 may perform IP header
decompression for data received from the UE, whereas the SDC-SMF
may perform IP header compression for data that is being prepared
to be sent to the UE.
[0071] The handling of small data by an SDC-SMF has a number of
advantages. For example, SMF functions, such as control rate, can
be leveraged for Control Plane (CP) data. Additionally, AMF
functionality is largely unmodified. For example, the AMF 510 may
simply forward data payload frames to the SMF. The processing of
the data may be performed by the SMF 502, e.g., based on the SDDSF
404, described in FIG. 4. This may provide an easier transition
between IP data (IPD) over the control plane to user plane
data.
[0072] In FIG. 5, the architecture illustrates data transport by a
home SMF. FIG. 6 illustrates an example of a roaming architecture
having a Home Public Land Mobile Network (HPLMN) 602 for a UE 604
that is located within a Visited Public Land Mobile Network (VPLMN)
606. In the HPLMN, a Home SDC-SMF (H-SDC-SMF) 608 may receive data
from AF 616, as described in connection with SDC-SMF 502.
Similarly, H-SDC-SMF 608 may perform IP header compression for IP
data forwarded by UPF 620 from DN 618. The H-SDC-SMF 608 may
process and store the data received from the AF 616 or the DN 618.
Then, the H-SDC-SMF 608 may forward the processed data to
Visited-SDC-SMF (V-SMF) 610. Thus, the V-SMF may be configured with
minimal additional functionality for CIoT. For example, the V-SMF
might not have at least some of the additional functionality of an
SDC-SMF 502. The V-SMF 610 may select the H-SDC-SMF 608. The V-SMF
may receive data processed by the H-SDC-SMF 608 and add the data to
an SM payload that is forwarded to the AMF 612 for transport to UE
604. IP data may be sent to H-SDC-SMF 608 and forwarded to the UE
604 after header compression, e.g., over N16. Interworking-NEF
(IWK-NEF) 622 may aggregate functions that can be exposed to the
HPLMN 602.
[0073] In another example, the V-SMF 610 may comprise a V-SDC-SMF.
FIG. 14 illustrates an example roaming architecture 1200 similar to
FIG. 6 and having a V-SDC-SMF 1210. Similar aspects to FIG. 6 have
been marked with the same reference numbers. The V-SDC-SMF 1210 may
perform IP header compression in addition to the encryption and
integrity check described for FIG. 6. The V-SDC-UPF 1210 may also
store small data for UEs in idle mode and forward the small data
when the UE is awake. Also, as illustrated in FIG. 14, a home UPF
620 may communicate data over an N9 interface with visited UPF 1220
that forwards the data to V-SDC-SMF 1210 for forwarding to the UE
604.
[0074] FIG. 7 illustrates an example NIDD protocol stack 700 for
transporting NIDD through SDC-SMF, (e.g., SDC-SMF 402, 502, 608).
FIG. 7 illustrates an example in which data frames may be delivered
to the SDC-SMF from the AF, e.g., via a T8 interface 702. The
SDC-SMF may package the data frames as NAS payload in a Session
Management (SM) message that is forwarded to the AMF, e.g., via an
N11 interface 704. The AMF then forwards the NAS payload to the UE,
e.g., in a Mobility Management (MM) message 708 from an MM protocol
706.
[0075] FIG. 8 illustrates an example IP protocol stack 800 for
transporting IPDD through SDC-SMF, e.g., 402, 502, 608. In FIG. 8,
IP data enters the core network via the UPF (e.g., UPF 508, 620).
For example, FIG. 5 illustrates IP data entering the core network
via UPF 508 from DN 506. The UPF forwards the data to the SDC-SMF,
e.g., via an N4 interface 802. The UPF may indicate to the SMF that
the data should be sent using NAS. The SDC-SMF may perform IP
header compression for the IP data. The processed data, with the
compressed IP header, may then be sent as an SM payload to the AMF,
e.g., via N11 interface 804 for forwarding to the UE. The data may
be sent as a NAS payload in a Session Management (SM) message that
is forwarded to the AMF. The AMF then forwards the NAS payload to
the UE, e.g., in a Mobility Management (MM) message 808 from an MM
protocol 806.
[0076] FIG. 9 illustrates an example of NIDD through SDC-SMF 902
with a configuration initiated by an AF 908. SDC-SMF 904 may
correspond to SMF 402, 502, 608, for example. Although only a
single AF 908 (e.g., AF 504, 616) is illustrated, data may enter a
core network from multiple AFs. AFs that generate the data may need
to configure the Unified Data Management (UDM) 902 to allow for
transport of their data to the UE using NIDD. Therefore, FIG. 9
illustrates AF 908 sending a configuration request 901 to the NEF
906 (e.g., NEF 514). The NEF performs NEF handling in response to
the configuration request and authorizes the AF using the UDM
information, e.g., sending an NIDD authorization request 903 to UDM
902. UDM 902 responds to the request with an NIDD Authorization
Response 905 and also provides SDC-SMF information for SDF-SMF 904
in the authorization response. The NEF 906 then forwards the
SDC-SMF information for SDF-SMF 904 to the AF 908 in an NIDD
configuration response 907. The AF 908 may initiate a T8 interface
with the SDC-SMF indicated by the SDC-SMF information, e.g., AF 908
may send a T8 set up request 909 to SDC-SMF 904 and receive a T8
set up response 911. The SDC-SMF sends information 913 to register
the AF, SDC-SMF pairing at UDM 902.
[0077] A UE may also set up PDU sessions using NIDD. FIG. 10
illustrates an example of PDU sessions set up for NIDD with UE
1002. In a first example, a UE may indicate at least a portion of
data is CIoT. In a second example, the UE may include an indication
in a registration request, such a flag, that indicates that the UE
requires CIoT transmission and NIDD. A RAN may select an AMF for
the NIDD based on the CIoT requirement indicated by the UE.
[0078] Encryption for NIDD may be performed in any of a number of
ways. In a first example, NAS encryption may be used. The UE may
leverage NAS encryption and integrity protection for the
transmission NIDD frames. The AMF may perform encryption/decryption
and integrity checks on the NAS payload. In a second example, SMF
based encryption may be used. In this second example, during PDU
session set up, the UE and SDC-SMF may derive a key for use with
frames of the NIDD PDU session. Keying material for the PDU session
may be provided to the SMF as part of the UE subscription or may be
received from the AF. In another example, encryption for NIDD
frames may be performed at the UPF. Keying material for the PDU
session may be provided to the UPF as part of the PDU session
establishment and may be derived based on authentication with the
network or may be obtained from the AF.
[0079] FIG. 10 illustrates an example of NIDD connection set up for
communication of NIDD between UE 1002 and AF 1016 via a core
network, e.g., that comprises RAN 1004, AMF 1006, SDC-SMF 1008, PCF
1010, UDM 1012, and NEF 1014. In this Protocol Data Unit (PDU)
session set up for NIDD, UE 1002 sends a PDU session request 1005
to AMF 1006 (e.g., AMF 510, 612) indicating NEF 1014 as the Access
Point Name (APN), and therefore, indicating a small data session
with NIDD. As illustrated in FIG. 10, an AF configuration 1001 may
be established between NEF 1014 and AF 1016, e.g., prior to the
request 1005. In an example in which the data is received at the
SDC-SMF directly from the AF 1016, a T8 session may be set up at
1003 between AF 1016 and SDC-SMF 1008 (e.g., SDC-SMF 402, 502, 608,
904) e.g., as described in connection with FIG. 9. As illustrated
in FIG. 5, a T8 interface may be established between the AF and the
NEF, and a second interface may be established between the NEF and
the SDC-SMF. The AMF may select, at 1007, an SDC-SMF for the PDU
session with UE 1002. The SDC-SMF may be selected not just based on
loading, but may also be selected based on capabilities of the SMF,
e.g., based on whether the SMF is small data capable. The AMF may
select the SDC-SMF 1008 based on a configuration for a
corresponding AF 1016, e.g., by selecting the SDC-SMF 1008 that was
configured in connection with AF 1016 when determining the SDC-SMF
to be used for the PDU session requested by UE 1002. The AMF 1006
may send an indication to the selected SDC-SMF 1008 to establish a
PDU session. The SDC-SMF 1008 may request subscriber data from UDM
1012, and a PDU session authentication authorization 1009 may be
performed. An Nsm is established between NEF 1014 and SDC-SMF 1008
at 1011, and an N2 PDU session is established and set up at 1013.
The UE 1002 may then transmit uplink data 1015 to RAN 1004 in an SM
payload. RAN 1004 forwards the SM payload to AMF 1006 that forwards
the SM payload to SDC-SMF 1008 for transport to AF 1016. The
SDC-SMF processes the SM payload to obtain the data and sends the
data to AF 1016 over the T8 interface. Similarly, downlink data
1017 may be transported from AF 1016 to SDC-SMF 1008 over T8. The
SDC-SMF 1008 includes the data as an SM payload and forwards the SM
payload to the AMF 1006 to be sent to UE 1002.
[0080] FIG. 11 illustrates an example of Mobile Terminated (MT)
data delivery. FIG. 11 illustrates aspects in which MT data
delivery with small data may be improved for UEs in idle modes,
e.g., CM-IDLE/RRC-IDLE. AMF 1106 may receive a data payload 1101,
e.g., from an SDC-SMF, as described in connection with FIGS. 5-10.
Upon receiving the data payload 1101, the AMF 1106 may send a
paging message containing the NAS SM message 1103 to the UE 1102.
The RAN 1104 may store the data and send a page 1105 to the UE 1102
with an indication that the page is for small data. For example,
the RAN may send an NAS MM over RRC. The UE responds with an RRC
connection request 1107. The RAN node responds with RRC an
connection setup 1109 and may piggyback the data (encrypted) to the
UE. The data may be encrypted. The UE may decrypt the encrypted
data and determine a return Message Authentication Code. The UE
then sends an ACK 1111 to RAN 1104 with a PDU session ID
indication. The RAN forwards the ACK 1113 to AMF, which forwards
the ACK 1115 to the SMF.
[0081] FIG. 13 is a flowchart 1300 of a method of wireless
communication. The method may be performed by aspects of a core
network, e.g., based on the example architectures of FIG. 5, FIG.
6, etc. Optional aspects of the method are illustrated with a
dashed line. The method enables the communication of small data
between a UE and network components in a manner that reduces the
overhead signaling required to transport the small data.
[0082] At 1304a, 1304b, or 1304c, data is received from at least
one of an AF, a DN and a user equipment. The data may comprise user
data rather than control data. The data may be received by a small
data capable SMF (e.g., SDC-SMF 402, 502, 608, 904, 1008). The data
may comprise small data, e.g., data below a size threshold. Thus,
the data may be referred to as small data and/or small user data.
Then, at 1306, the SMF processes the data for transport with a low
overhead, e.g., as a session management payload over an NAS
protocol. The overhead is lower in overhead than the case where a
service request and additional signaling procedure is required to
establish a user plane connection. When going through the NAS, the
establishment of the user plane is not required, thereby reducing
the overhead to transport the data. The SMF may process the data
for transmission to the UE. For data received from the UE, the SMF
may process the data for transmission to the AF or the DN.
[0083] At 1304a, the data may be received from an AF external to
the core network, e.g., via a T8 interface. In one example, the
data may be received at an SMF directly from the AF, e.g., via a T8
interface. In another example, as illustrated in FIG. 5, an NEF may
comprise the T8 interface with the AF and may have another
interface to the SMF. Thus, the data may be received by the SMF
indirectly from the AF. At 1304b, the data may be received from a
DN external to the core network, e.g., via an N6 interface. As
illustrated in FIG. 5, the data may be received by the SMF
indirectly from the DN, e.g., via a UPF. The SMF processes the
received data at 1306. For data received from the AF or the DN at
1304a/1304b, the SMF processes the data for transport to the UE.
The SMF may then transport the data to the user equipment, at 1316,
as an SM payload, as described in connection with FIGS. 5, 6, and
10. The SM payload, e.g., terminates within the session management
functionality of the UE. One example would be an IP address
assigned to the UE. However, when the SM payload is user data, the
session management function in the UE may strip out the data and
forward the data to the application stack in the UE. The data may
be transmitted to the user equipment via an AMF, e.g., as described
in connection with FIGS. 5, 6, and 10.
[0084] At 1304c, the data may be received in an SM payload from the
user equipment. In this example the SMF processes the data for
transport to the AF or to the DN. Then, the SMF may transport the
data to the AF or to the DN, at 1320, e.g., after processing the SM
payload to obtain the data. The SMF may terminate a T8 interface
for the data entering the core network from an AF, e.g., as in the
examples illustrated in FIGS. 5 and 6. As well, the NEF may
terminate the T8 interface for the data entering the core network
from the AF, e.g., as illustrated in FIGS. 5 and 6.
[0085] The data may be processed at the SMF at 1306 based on a
configuration of a sender of the data. The data may be processed at
1306 to be transmitted in a manner specific to small data, e.g.,
data below a threshold size. Thus, the data may be processed due to
the data being small data and/or when the sender has an appropriate
configuration.
[0086] Thus, in the example in which the data is received from an
AF at 1304a or a DN at 1304b, the small data may be processed for
transport to the UE at 1316, e.g., as an SM payload. The SMF may
perform IP compression, e.g., IP header compression at 1308.
Similarly, when the data is received from the UE and is directed to
the DN, the SMF may perform IP header decompression, at 1308,
before transporting the data to the DN, e.g., via a UPF.
[0087] At times, the UE may be in an idle mode or other low power
mode, in which the UE is not actively receiving transmissions. The
SMF may store the data at 1312 when the user equipment is in an
idle mode. An idle mode may include when the UE is in an RRC idle
mode, a Connected Mode (CM) idle, etc. Then, at 1314, the UE may
forward the data to the user equipment from the SMF when the user
equipment is in an awake mode, e.g., when the UE is in an RRC
connected mode, CM connected mode, etc. For example, the UE may be
considered to be in an awake mode when the AMF does not need to
page UE to communicate with the UE. The network may receive an
indication from the UE indicating that the UE is ready to receive
the data. The indication may trigger the SMF to transport the data
to the UE. FIG. 16 illustrates an example of storage of data and
later communication with a UE when the UE is in an idle mode.
[0088] As illustrated at 1310, the SMF may encrypt the data based
on an SMF encryption key, wherein the SMF encryption key comprises
a shared key between the user equipment and the SMF.
[0089] As in the example illustrated in FIG. 6, the SMF may
comprise a H-SMF. Thus, at 1318, the SMF may forward the processed
data to a V-SMF for transmission to the user equipment. The SMF may
perform the processing prior to providing the data to the V-SMF. In
other examples, the SMF may be the V-SMF and may perform the
processing of the data after received from an H-SMF and prior to
transporting the data to the UE.
[0090] The method may further include selecting the SMF from a
plurality of SIVIFs at 1302, e.g., based on a capability of the SMF
to process the data. For example, the AMF may select the SMF for a
PDU session, e.g., as described in connection with FIG. 10. In
another example, the SMF may be selected by an NEF (e.g., 514, 906,
1014).
[0091] FIG. 14 is a conceptual data flow diagram 1400 illustrating
the data flow between different means/components in an exemplary
apparatus 1402. The apparatus may be a core network component,
e.g., an SMF (e.g., e.g., SDC-SMF 402, 502, 608, 904, 1008. The
apparatus includes a reception component 1404 that receives
communication, e.g., from other network components and/or from
UE(s) 1450. The apparatus includes a data component 1408 configured
to receive user data below a size threshold from at least one of an
AF 1541, a DN 1453, or a UE 1450. The apparatus includes a
processing component 1410 configured to process the data at an SMF
for transport with a low overhead as a session management payload
over a NAS protocol. The apparatus includes a transmission
component 1406 configured to transport the data, e.g., from the SMF
to the UE 1450 as a SM payload. The data may be transmitted to the
UE 1450 via an AMF 1455. The apparatus may include a buffer
component 1412 configured to store the data, e.g., at the SMF, for
the UE 1450 when the UE 1450 is in an idle mode. Then, the
transmission component 1406 may forward the data to the user
equipment from the SMF when the UE 1450 is in an awake mode. The
data may be received at the data component 1408 in an SM payload
from the UE 1450. In this example, the transmission component 1406
may be configured to transport the data, e.g., from the SMF, to the
AF 1451 or the DN 1453. The processing component 1410 may comprise
a compression component 1414 configured to perform IP header
compression on the data, e.g., at the SMF. The processing component
1410 may comprise an encryption component 1416 configured to
encrypt data with an SMF encryption key, wherein the SMF encryption
key comprises a shared key between the user equipment and the SMF,
e.g., as determined by key component 1422. The apparatus may be
comprised in or may comprise a home SMF. Thus, the apparatus may
comprise a V-SMF component 1420 configured to forward the processed
data to a visitor SMF 1459 for transmission to the UE 1450. Another
network component, such as an AMF 1455 may be configured to select
the SMF from a plurality of SMFs based on a capability of the SMF
to process the data. In another example, the SMF may be selected by
an NEF.
[0092] The apparatus/core network may include components that
perform each of the blocks of the algorithm in the aforementioned
flowcharts of FIG. 9, 10, 11, or 13. As such, each block in the
aforementioned flowcharts of FIG. 9, 10, 11, or 13 may be performed
by a component and the apparatus may include one or more of those
components. The components may be one or more hardware components
specifically configured to carry out the stated
processes/algorithm, implemented by a processor configured to
perform the stated processes/algorithm, stored within a
computer-readable medium for implementation by a processor, or some
combination thereof.
[0093] FIG. 15 is a diagram 1500 illustrating an example of a
hardware implementation for an apparatus 1402' employing a
processing system 1514. The processing system 1514 may be
implemented with a bus architecture, represented generally by the
bus 1524. The bus 1524 may include any number of interconnecting
buses and bridges depending on the specific application of the
processing system 1514 and the overall design constraints. The bus
1524 links together various circuits including one or more
processors and/or hardware components, represented by the processor
1504, the components 1404, 1406, 1408, 1410, 1412, 1414, 1416,
1420, 1422, and the computer-readable medium/memory 1506. The bus
1524 may also link various other circuits such as timing sources,
peripherals, voltage regulators, and power management circuits,
which are well known in the art, and therefore, will not be
described any further.
[0094] The processing system 1514 may be coupled to a transceiver
1510. The transceiver 1510 is coupled to one or more antennas 1520.
The transceiver 1510 provides a means for communicating with
various other apparatus over a transmission medium. The transceiver
1510 receives a signal from the one or more antennas 1520, extracts
information from the received signal, and provides the extracted
information to the processing system 1514, specifically the
reception component 1404. In addition, the transceiver 1510
receives information from the processing system 1514, specifically
the transmission component 1406, and based on the received
information, generates a signal to be applied to the one or more
antennas 1520. The processing system 1514 includes a processor 1504
coupled to a computer-readable medium/memory 1506. The processor
1504 is responsible for general processing, including the execution
of software stored on the computer-readable medium/memory 1506. The
software, when executed by the processor 1504, causes the
processing system 1514 to perform the various functions described
supra for any particular apparatus. The computer-readable
medium/memory 1506 may also be used for storing data that is
manipulated by the processor 1504 when executing software. The
processing system 1514 further includes at least one of the
components 1404, 1406, 1408, 1410, 1412, 1414, 1416, 1420, 1422.
The components may be software components running in the processor
1504, resident/stored in the computer readable medium/memory 1506,
one or more hardware components coupled to the processor 1504, or
some combination thereof. The processing system 1514 may be a
component of the core network and may include the memory and/or at
least one of the TX processor, the RX processor, and the
controller/processor.
[0095] In one configuration, the core network for wireless
communication may include means for receiving user data below a
size threshold from at least one of an AF, a DN, and a user
equipment; means for processing the data at an SMF for transport
with a low overhead as a session management payload over a NAS
protocol; means for transporting the data from the SMF to the user
equipment as an SM payload; means for transporting the data from
the SMF to the AF; means for performing IP header compression on
the data by the SMF; means for storing the data at the SMF for the
user equipment when the user equipment is in an idle mode; means
for forwarding the data to the user equipment from the SMF when the
user equipment is in an awake mode; means for encrypting data by
the SMF with an SMF encryption key; means for forwarding the
processed data to a visitor SMF for transmission to the user
equipment; and means for selecting the SMF from a plurality of SMFs
based on a capability of the SMF to process the data. The
aforementioned means may be one or more of the aforementioned
components of the apparatus 1402/1402' or core network and/or a
processing system 1514 of the apparatus 1402/1402' configured to
perform the functions recited by the aforementioned means. As
described supra, the processing system 1514 may include a TX
Processor, the RX Processor, and the controller/processor. As such,
in one configuration, the aforementioned means may be the TX
Processor, the RX Processor, and the controller/processor
configured to perform the functions recited by the aforementioned
means.
[0096] FIG. 16 is a flowchart 1600 of a method of wireless
communication. The method may be performed by a UE (e.g., UE 104,
350, 512, 604, 1002, 1102, the apparatus 1702, 1702'). Optional
aspects are illustrated with a dashed line. The method may enable
the UE to send and/or receive small data in a manner that reduces
the overhead signaling requirements for the UE to transmit/receive
the small data.
[0097] At 1602, the UE establishes a session with an SMF (e.g.,
SDC-SMF 402, 502, 608, 904, 1008) for the communication of user
data below a size threshold. At 1610, the UE communicates data with
at least one of an AF, a DN, wherein the data is communicated with
the SMF for transport with a low overhead as a session management
payload over an NAS protocol.
[0098] The communicating the data at 1610 may include receiving the
data at 1612 from the AF or the DN as a SM payload received from
the SMF. The SM payload, e.g., terminates within the session
management functionality of the UE. When the SM payload is user
data, the session management function in the UE may strip out the
data and forward the data to the application stack in the UE. In
another example, the communicating the data at 1610 may include
transmitting at 1614 the data to the SMF as a SM payload for
transport to the AF or the DN.
[0099] The SMF may buffer data for a UE in an idle mode, e.g., RRC
idle, CM idle, etc. Therefore, the UE may receive an indication of
stored data for the user equipment at the SMF at 1606. At 1608, the
UE may transmit a second indication that the UE is ready to receive
the stored data. Then, the UE may receive the data from the SMF,
e.g., at 1612 in response to the second indication.
[0100] The data may comprise encrypted data encrypted based on an
SMF encryption key, wherein the SMF encryption key comprises a
shared key between the user equipment and the SMF.
[0101] FIG. 17 is a conceptual data flow diagram 1700 illustrating
the data flow between different means/components in an exemplary
apparatus 1702. The apparatus may be a UE (e.g., UE 104, 350, 512,
604, 1002, 1102, the apparatus 1702, 1702'). The apparatus includes
a session component 1708 configured to establish a session with an
SMF 1751 for communication of user data below a size threshold,
e.g., by transmitting a session request. The apparatus includes a
communication component 1710 configured to communicate with at
least one of an AF 1755 or a DN 1757, wherein the data is
communicated with the SMF for transport with a low overhead as an
SM payload over a NAS protocol. The communication component 1710
may receive, via reception component 1704, the data from the AF or
the DN as the SM payload received from the SMF and/or may transmit
the data, via transmission component 1706, to the SMF as the SM
payload for transport to the AF or the DN. The apparatus may
comprise an indication component 1714 configured to receive an
indication of stored data for the user equipment at the SMF and to
transmit a second indication that the UE is ready to receive the
stored data. The reception component and communication component
1710 may be configured to receive the data from the SMF 1751 in
response to the second indication. The data may comprise encrypted
data encrypted based on an SMF encryption key, wherein the SMF
encryption key comprises a shared key between the user equipment
and the SMF. Thus, the apparatus may comprise a key component 1716
configured to exchange key information with the SMF 1751. The data
may be communicated with the SMF 1751 via AMF 1750.
[0102] The UE may include components that perform aspects of the
algorithm in the aforementioned flowcharts of FIGS. 9-11 and 16. As
such, blocks in the aforementioned flowcharts of FIGS. 9-11 and 16
may be performed by a component and the apparatus may include one
or more of those components. The components may be one or more
hardware components specifically configured to carry out the stated
processes/algorithm, implemented by a processor configured to
perform the stated processes/algorithm, stored within a
computer-readable medium for implementation by a processor, or some
combination thereof.
[0103] FIG. 18 is a diagram 1800 illustrating an example of a
hardware implementation for an apparatus 1702' employing a
processing system 1814. The processing system 1814 may be
implemented with a bus architecture, represented generally by the
bus 1824. The bus 1824 may include any number of interconnecting
buses and bridges depending on the specific application of the
processing system 1814 and the overall design constraints. The bus
1824 links together various circuits including one or more
processors and/or hardware components, represented by the processor
1804, the components 1704, 1706, 1708, 1710, 1714, 1716, and the
computer-readable medium/memory 1806. The bus 1824 may also link
various other circuits such as timing sources, peripherals, voltage
regulators, and power management circuits, which are well known in
the art, and therefore, will not be described any further.
[0104] The processing system 1814 may be coupled to a transceiver
1810. The transceiver 1810 is coupled to one or more antennas 1820.
The transceiver 1810 provides a means for communicating with
various other apparatus over a transmission medium. The transceiver
1810 receives a signal from the one or more antennas 1820, extracts
information from the received signal, and provides the extracted
information to the processing system 1814, specifically the
reception component 1704. In addition, the transceiver 1810
receives information from the processing system 1814, specifically
the transmission component 1706, and based on the received
information, generates a signal to be applied to the one or more
antennas 1820. The processing system 1814 includes a processor 1804
coupled to a computer-readable medium/memory 1806. The processor
1804 is responsible for general processing, including the execution
of software stored on the computer-readable medium/memory 1806. The
software, when executed by the processor 1804, causes the
processing system 1814 to perform the various functions described
supra for any particular apparatus. The computer-readable
medium/memory 1806 may also be used for storing data that is
manipulated by the processor 1804 when executing software. The
processing system 1814 further includes at least one of the
components 1704, 1706, 1708, 1710, 1714, 1716. The components may
be software components running in the processor 1804,
resident/stored in the computer readable medium/memory 1806, one or
more hardware components coupled to the processor 1804, or some
combination thereof. The processing system 1814 may be a component
of the UE 350 and may include the memory 360 and/or at least one of
the TX processor 368, the RX processor 356, and the
controller/processor 359.
[0105] In one configuration, the UE for wireless communication may
include means for establishing a session with an SMF, means for
communicating user data below a size threshold with at least one of
an AF or a DN, wherein the data is communicated with the SMF for
transport with a low overhead as an SM payload over an NAS
protocol, means for receiving the data from the AF or the DN as the
SM payload received from the SMF, means for transmitting the data
to the SMF as an SM payload for transport to the AF or the DN,
means for receiving an indication of stored data for the user
equipment at the SMF, means for transmitting an second indication
that the UE is ready to receive the stored data, and means for
receiving the data from the SMF in response to the second
indication. The aforementioned means may be one or more of the
aforementioned components of the apparatus 1702 and/or a processing
system 1814 of the apparatus 1702' configured to perform the
functions recited by the aforementioned means. As described supra,
the processing system 1814 may include the TX Processor 368, the RX
Processor 356, and the controller/processor 359. As such, in one
configuration, the aforementioned means may be the TX Processor
368, the RX Processor 356, and the controller/processor 359
configured to perform the functions recited by the aforementioned
means.
[0106] Aspects may include a processing system includes a processor
coupled to a computer-readable medium/memory. The processor may be
responsible for general processing, including the execution of
software stored on the computer-readable medium/memory. The
software, when executed by the processor, causes the processing
system to perform the various functions described supra for any
particular apparatus. The computer-readable medium/memory may also
be used for storing data that is manipulated by the processor when
executing software. It is understood that the specific order or
hierarchy of blocks in the processes/flowcharts disclosed is an
illustration of exemplary approaches. Based upon design
preferences, it is understood that the specific order or hierarchy
of blocks in the processes/flowcharts may be rearranged. Further,
some blocks may be combined or omitted. The accompanying method
claims present elements of the various blocks in a sample order,
and are not meant to be limited to the specific order or hierarchy
presented.
[0107] The previous description is provided to enable any person
skilled in the art to practice the various aspects described
herein. Various modifications to these aspects will be readily
apparent to those skilled in the art, and the generic principles
defined herein may be applied to other aspects. Thus, the claims
are not intended to be limited to the aspects shown herein, but is
to be accorded the full scope consistent with the language claims,
wherein reference to an element in the singular is not intended to
mean "one and only one" unless specifically so stated, but rather
"one or more." The word "exemplary" is used herein to mean "serving
as an example, instance, or illustration." Any aspect described
herein as "exemplary" is not necessarily to be construed as
preferred or advantageous over other aspects. Unless specifically
stated otherwise, the term "some" refers to one or more.
Combinations such as "at least one of A, B, or C," "one or more of
A, B, or C," "at least one of A, B, and C," "one or more of A, B,
and C," and "A, B, C, or any combination thereof" include any
combination of A, B, and/or C, and may include multiples of A,
multiples of B, or multiples of C. Specifically, combinations such
as "at least one of A, B, or C," "one or more of A, B, or C," "at
least one of A, B, and C," "one or more of A, B, and C," and "A, B,
C, or any combination thereof" may be A only, B only, C only, A and
B, A and C, B and C, or A and B and C, where any such combinations
may contain one or more member or members of A, B, or C. All
structural and functional equivalents to the elements of the
various aspects described throughout this disclosure that are known
or later come to be known to those of ordinary skill in the art are
expressly incorporated herein by reference and are intended to be
encompassed by the claims. Moreover, nothing disclosed herein is
intended to be dedicated to the public regardless of whether such
disclosure is explicitly recited in the claims. The words "module,"
"mechanism," "element," "device," and the like may not be a
substitute for the word "means." As such, no claim element is to be
construed as a means plus function unless the element is expressly
recited using the phrase "means for."
* * * * *