U.S. patent application number 14/289002 was filed with the patent office on 2015-12-03 for user context aware throttling of transition attempts to connected mode.
This patent application is currently assigned to Apple Inc.. The applicant listed for this patent is Apple Inc.. Invention is credited to Sree Ram Kodali, Srinivas Pasupuleti, Aravind Radhakrishnan, Bharath Narasimha Rao, Naveen Rawat, Sachin Sane.
Application Number | 20150350972 14/289002 |
Document ID | / |
Family ID | 54481701 |
Filed Date | 2015-12-03 |
United States Patent
Application |
20150350972 |
Kind Code |
A1 |
Rao; Bharath Narasimha ; et
al. |
December 3, 2015 |
User Context Aware Throttling of Transition Attempts to Connected
Mode
Abstract
Throttling of transition attempts to connected mode based on
user context. A wireless device may camp on a serving cell. A
motion state of the wireless device may be monitored. One or more
connected mode transition procedures on the serving cell may be
attempted. If at least a threshold number of connected mode
transition procedures fail on the serving cell while the wireless
device is stationary, further connected mode transition attempts
may be throttled for up to a certain amount of time. Alternatively,
or in addition, the wireless device may bar itself from camping on
that cell for up to a certain amount of time. Either or both of
throttling connected mode transition attempts or barring cells may
also be based on other aspects of user context, such as display
state.
Inventors: |
Rao; Bharath Narasimha;
(Sunnyvale, CA) ; Kodali; Sree Ram; (Sunnyvale,
CA) ; Pasupuleti; Srinivas; (San Jose, CA) ;
Sane; Sachin; (Santa Clara, CA) ; Radhakrishnan;
Aravind; (Campbell, CA) ; Rawat; Naveen; (San
Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Apple Inc. |
Cupertino |
CA |
US |
|
|
Assignee: |
Apple Inc.
Cupertino
CA
|
Family ID: |
54481701 |
Appl. No.: |
14/289002 |
Filed: |
May 28, 2014 |
Current U.S.
Class: |
455/441 |
Current CPC
Class: |
H04W 28/08 20130101;
H04W 36/0083 20130101; H04W 36/32 20130101; H04W 76/18 20180201;
H04W 74/0833 20130101 |
International
Class: |
H04W 36/00 20060101
H04W036/00; H04W 28/08 20060101 H04W028/08; H04W 74/08 20060101
H04W074/08; H04W 36/32 20060101 H04W036/32 |
Claims
1. A wireless user equipment (UE) device, comprising: a radio;
motion sensing circuitry; and a processing element operably coupled
to the radio; wherein the radio, motion sensing circuitry, and
processing element are configured to: attempt one or more
procedures to transition from an idle mode to a connected mode via
cellular communication with a first base station; determine whether
or not the UE is stationary; and throttle further connected mode
transition procedure attempts for up to a first predetermined
period of time if a number of most recent connected mode transition
procedure attempts equal to a first threshold number have failed
and the UE is stationary.
2. The UE of claim 1, wherein the radio, motion sensing circuitry,
and processing element are further configured to: determine a user
activity level of the UE based on one or more user activity
indicators, wherein throttling further connected mode transition
attempts for up to the first predetermined period of time is also
contingent upon the one or more user activity indicators being in a
state indicative of low user activity.
3. The UE of claim 2, wherein the one or more user activity
indicators comprise an on/off status of a display of the UE.
4. The UE of claim 1, wherein the radio, motion sensing circuitry,
and processing element are further configured to: determine whether
any cell selections or re-selections have occurred during the most
recent connected mode transition procedure attempts, wherein
throttling further connected mode transition attempts for up to the
first predetermined period of time is also contingent upon no cell
selections or re-selections having occurred during the most recent
connected mode transition procedure attempts.
5. The UE of claim 1, wherein the radio, motion sensing circuitry,
and processing element are further configured to cease throttling
further connected mode transition procedure attempts if: the first
predetermined period of time expires; or the UE ceases to be
stationary.
6. The UE of claim 1, wherein the radio, motion sensing circuitry,
and processing element are further configured to cease throttling
further connected mode transition procedure attempts if: the UE
re-selects to a different cell on which connected mode transition
procedure attempts are not currently throttled.
7. A method for a wireless user equipment (UE) device, comprising:
camping on a first cell in an idle mode; performing a plurality of
successive attempts to transition to a connected mode on the first
cell, wherein each successive connected mode transition attempt is
performed based on failure of the previous connected mode
transition attempt, wherein each successive connected mode
transition attempt comprises transmitting with an incrementally
increased transmit power relative to the previous connected mode
transition attempt; determining that the UE is stationary;
determining that a first threshold number of successive connected
mode transition attempts on the first cell have failed while the UE
is stationary; barring camping on the first cell for up to a first
predetermined period of time based on determining that the first
threshold number of successive connected mode transition attempts
have failed while the UE is stationary.
8. The method of claim 7, further comprising: unbarring camping on
the first cell upon expiration of the first predetermined period of
time.
9. The method of claim 7, further comprising: determining that the
UE is no longer stationary prior to expiration of the first
predetermined period of time; unbarring camping on the first cell
prior to expiration of the first predetermined period of time based
on determining that the UE is no longer stationary prior to
expiration of the first predetermined period of time.
10. The method of claim 7, further comprising: determining that one
or more user activity indicators are in a state indicative of low
user activity, wherein barring camping on the first cell for up to
the first predetermined period of time is further based on
determining that one or more user activity indicators are in the
state indicative of low user activity.
11. The method of claim 10, further comprising: determining that
one or more of the user activity indicators have changed to a state
indicative of high user activity prior to expiration of the first
predetermined period of time; unbarring camping on the first cell
prior to expiration of the first predetermined period of time based
on determining that one or more of the user activity indicators
have changed to a state indicative of high user activity prior to
expiration of the first predetermined period of time.
12. The method of claim 7, wherein in addition to the first cell,
camping on one or more other cells is also barred, wherein the
method further comprises: re-selecting to a cell on which camping
is not barred in response to barring camping on the first cell; and
performing at least one connected mode transition attempt on the
cell on which camping is not barred.
13. The method of claim 7, further comprising, after expiration of
the first predetermined period of time: performing one or more
iterations of barring camping on the first cell, wherein each
successive iteration of barring camping on the first cell is
performed if the UE is still stationary and if a respective
threshold number of further successive connected mode transition
attempts on the first cell have failed, wherein the respective
threshold number of successive further connected mode transition
attempts for each successive iteration of barring camping on the
first cell is less than a threshold number of successive further
connected mode transition attempts for a previous iteration,
wherein camping on the first cell is barred at each successive
iteration for up to a respective predetermined period of time which
is greater than a predetermined period of time up to which camping
on the first cell is barred for the previous iteration.
14. A non-transitory computer accessible memory medium comprising
program instructions which, when executed at a wireless user
equipment (UE) device, cause the UE to: camp on a serving cell in
an idle mode; attempt at least one RACH procedure to transition
from the idle mode to a connected mode; monitor a motion state of
the UE; and throttle RACH procedure attempts for a first
predetermined period of time if the UE is stationary, and if a
first number of most recent RACH procedure attempts equal to a
first threshold number have failed, and if no cell selections or
re-selections been performed by the UE in the duration of the first
number of most recent RACH procedure attempts, and if a display of
the UE is off.
15. The memory medium of claim 14, wherein, when executed, the
program instructions further cause the UE to: resume further RACH
procedure attempts after expiration of the first predetermined
period of time.
16. The memory medium of claim 14, wherein, when executed, the
program instructions further cause the UE to: if the UE is still
stationary; and if a second number of most recent RACH procedure
attempts after resuming further RACH procedure attempts equal to a
second threshold number have failed; and if no cell selections or
re-selections been performed by the UE in the duration of the
second number of most recent RACH procedure attempts; and if a
display of the UE is still off; then throttle further RACH
procedure attempts for a second predetermined period of time,
wherein the second threshold number is less than the first
threshold number, wherein the second predetermined period of time
is greater than the first predetermined period of time.
17. The memory medium of claim 14, wherein, when executed, the
program instructions further cause the UE to: resume further RACH
procedure attempts prior to expiration of the first predetermined
period of time if any cell selections or re-selections are
performed by the UE prior to expiration of the first predetermined
period of time.
18. The memory medium of claim 14, wherein, when executed, the
program instructions further cause the UE to: resume further RACH
procedure attempts prior to expiration of the first predetermined
period of time if the UE is no longer stationary prior to
expiration of the first predetermined period of time.
19. The memory medium of claim 14, wherein, when executed, the
program instructions further cause the UE to: resume further RACH
procedure attempts prior to expiration of the first predetermined
period of time if the display of the UE is powered on prior to
expiration of the first predetermined period of time.
20. The memory medium of claim 14, wherein, when executed, the
program instructions further cause the UE to: resume further RACH
procedure attempts prior to expiration of the first predetermined
period of time if serving cell signal strength and/or quality
changes by at least a signal strength threshold and/or a signal
quality threshold prior to expiration of the first predetermined
period of time.
Description
FIELD
[0001] The present application relates to wireless devices, and
more particularly to a system and method for a wireless device to
enable and disable connected mode transition attempt throttling
based at least in part on device motion.
DESCRIPTION OF THE RELATED ART
[0002] Wireless communication systems are rapidly growing in usage.
Further, wireless communication technology has evolved from
voice-only communications to also include the transmission of data,
such as Internet and multimedia content. Some examples of wireless
communication standards include GSM, UMTS (WCDMA), LTE, LTE
Advanced (LTE-A), 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD,
eHRPD), IEEE 802.11 (WLAN or Wi-Fi), IEEE 802.16 (WiMAX),
Bluetooth, and others.
[0003] Many wireless communication technologies, such as cellular
communication technologies, provide mobile communication
capabilities to wireless devices, such as cellular phones. For
example, cellular communication services may be provided by
deploying a network of cells on various radio frequencies and at
various locations, such that a wireless device may select and
attach to a serving cell, with the capability to re-select to a new
serving cell. Such a wireless device may be able to camp on its
serving cell in an idle mode, or transition (for example using a
random access channel (RACH) procedure) to a connected mode in
which network data exchange may occur.
SUMMARY
[0004] Embodiments are presented herein of methods for wireless
devices to enable and disable connected mode transition attempt
throttling based at least in part on device motion, and of devices
configured to implement the methods.
[0005] According to the techniques described herein, a wireless
device which is stationary and experiencing difficulty
transitioning to connected mode with its serving cell may enable
throttling of any further such transition (e.g., RACH) attempts, or
alternatively bar camping on that serving cell, for up to a certain
period of time.
[0006] In some instances, such throttling may be enabled only under
certain conditions. For example, a wireless device may not enable
such throttling (or bar the serving cell) if user activity
indicators (such as device display status) are in a state
indicative of high user activity (e.g., on). As another example, if
the wireless device has selected or re-selected to its current
serving cell relatively recently (e.g., and has not yet met a
threshold number of failures to move to connected mode on the
current serving cell), wireless device may not (yet) enable such
throttling (or bar the serving cell).
[0007] After enabling throttling of transition attempts to
connected mode (or the serving cell is barred), various conditions
may trigger disabling of the such throttling (or unbarring of the
serving cell). For example, if the prescribed period of time
expires, such throttling may be again disabled (or the serving cell
unbarred). Likewise, if user activity increases, the device is no
longer stationary, the signal strength and/or quality of the
serving cell changes (e.g., improves) by a significant amount
(e.g., by at least a threshold amount), or the wireless device
re-selects to a new serving cell, such throttling may be disabled,
even before the prescribed period of time expires.
[0008] The techniques described herein may be implemented in and/or
used with a number of different types of devices, including but not
limited to cellular phones, tablet computers, wearable computing
devices, portable media players, cellular network infrastructure
equipment, servers, and any of various other computing devices.
[0009] This Summary is intended to provide a brief overview of some
of the subject matter described in this document. Accordingly, it
will be appreciated that the above-described features are merely
examples and should not be construed to narrow the scope or spirit
of the subject matter described herein in any way. Other features,
aspects, and advantages of the subject matter described herein will
become apparent from the following Detailed Description, Figures,
and Claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A better understanding of the present subject matter can be
obtained when the following detailed description of the embodiments
is considered in conjunction with the following drawings, in
which:
[0011] FIG. 1 illustrates an exemplary (and simplified) wireless
communication system;
[0012] FIG. 2 illustrates an exemplary base station (BS) in
communication with an exemplary wireless user equipment (UE)
device;
[0013] FIG. 3 illustrates an exemplary block diagram of a UE;
[0014] FIG. 4 illustrates an exemplary block diagram of a BS;
[0015] FIG. 5 is a flowchart diagram illustrating an exemplary
method for a UE to enable or disable connected mode transition
procedure throttling based at least in part on device motion;
and
[0016] FIG. 6 is a signal flow diagram illustrating an exemplary
RACH procedure.
[0017] While the features described herein may be susceptible to
various modifications and alternative forms, specific embodiments
thereof are shown by way of example in the drawings and are herein
described in detail. It should be understood, however, that the
drawings and detailed description thereto are not intended to be
limiting to the particular form disclosed, but on the contrary, the
intention is to cover all modifications, equivalents and
alternatives falling within the spirit and scope of the subject
matter as defined by the appended claims.
DETAILED DESCRIPTION
Acronyms
[0018] The following acronyms are used in the present
disclosure:
[0019] UE: User Equipment
[0020] BS: Base Station
[0021] RAT: Radio Access Technology
[0022] 3GPP: Third Generation Partnership Project
[0023] 3GPP2: Third Generation Partnership Project 2
[0024] GSM: Global System for Mobile Communication
[0025] UMTS: Universal Mobile Telecommunication System
[0026] LTE: Long Term Evolution
[0027] RACH: Random Access Procedure
[0028] RNTI: Radio Network Temporary Identifier
[0029] RA-RNTI: Random Acces RNTI
[0030] C-RNTI: Cell RNTI
[0031] TC-RNTI: Temporary Cell RNTI
[0032] TMSI: Temporary Mobile Subscriber Identity
[0033] S-TMSI: System Architecture Evolution TMSI
Terms
[0034] The following is a glossary of terms used in the present
disclosure:
[0035] Memory Medium--Any of various types of non-transitory memory
devices or storage devices. The term "memory medium" is intended to
include an installation medium, e.g., a CD-ROM, floppy disks, or
tape device; a computer system memory or random access memory such
as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile
memory such as a Flash, magnetic media, e.g., a hard drive, or
optical storage; registers, or other similar types of memory
elements, etc. The memory medium may include other types of
non-transitory memory as well or combinations thereof. In addition,
the memory medium may be located in a first computer system in
which the programs are executed, or may be located in a second
different computer system which connects to the first computer
system over a network, such as the Internet. In the latter
instance, the second computer system may provide program
instructions to the first computer for execution. The term "memory
medium" may include two or more memory mediums which may reside in
different locations, e.g., in different computer systems that are
connected over a network. The memory medium may store program
instructions (e.g., embodied as computer programs) that may be
executed by one or more processors.
[0036] Carrier Medium--a memory medium as described above, as well
as a physical transmission medium, such as a bus, network, and/or
other physical transmission medium that conveys signals such as
electrical, electromagnetic, or digital signals.
[0037] Programmable Hardware Element--includes various hardware
devices comprising multiple programmable function blocks connected
via a programmable interconnect. Examples include FPGAs (Field
Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOAs
(Field Programmable Object Arrays), and CPLDs (Complex PLDs). The
programmable function blocks may range from fine grained
(combinatorial logic or look up tables) to coarse grained
(arithmetic logic units or processor cores). A programmable
hardware element may also be referred to as "reconfigurable
logic".
[0038] Computer System--any of various types of computing or
processing systems, including a personal computer system (PC),
mainframe computer system, workstation, network appliance, Internet
appliance, personal digital assistant (PDA), television system,
grid computing system, or other device or combinations of devices.
In general, the term "computer system" can be broadly defined to
encompass any device (or combination of devices) having at least
one processor that executes instructions from a memory medium.
[0039] User Equipment (UE) (or "UE Device")--any of various types
of computer systems devices which are mobile or portable and which
performs wireless communications. Examples of UE devices include
mobile telephones or smart phones (e.g., iPhone.TM.,
Android.TM.-based phones), portable gaming devices (e.g., Nintendo
DS.TM., PlayStation Portable.TM., Gameboy Advance.TM., iPhone.TM.),
laptops, PDAs, portable Internet devices, music players, data
storage devices, or other handheld devices, etc. In general, the
term "UE" or "UE device" can be broadly defined to encompass any
electronic, computing, and/or telecommunications device (or
combination of devices) which is easily transported by a user and
capable of wireless communication.
[0040] Base Station--The term "Base Station" has the full breadth
of its ordinary meaning, and at least includes a wireless
communication station installed at a fixed location and used to
communicate as part of a wireless telephone system or radio
system.
[0041] Cell--The term "cell" as used herein may refer to an area in
which wireless communication services are provided on a radio
frequency by a cell site or base station. A cell may be identified
in various instances by the frequency on which the cell is
deployed, by a network (e.g., PLMN) to which the cell belongs,
and/or a cell identifier (cell id), among various
possibilities.
[0042] Processing Element--refers to various elements or
combinations of elements. Processing elements include, for example,
circuits such as an ASIC (Application Specific Integrated Circuit),
portions or circuits of individual processor cores, entire
processor cores, individual processors, programmable hardware
devices such as a field programmable gate array (FPGA), and/or
larger portions of systems that include multiple processors.
[0043] Channel--a medium used to convey information from a sender
(transmitter) to a receiver. It should be noted that since
characteristics of the term "channel" may differ according to
different wireless protocols, the term "channel" as used herein may
be considered as being used in a manner that is consistent with the
standard of the type of device with reference to which the term is
used. In some standards, channel widths may be variable (e.g.,
depending on device capability, band conditions, etc.). For
example, LTE may support scalable channel bandwidths from 1.4 MHz
to 20 MHz. In contrast, WLAN channels may be 22 MHz wide while
Bluetooth channels may be 1 Mhz wide. Other protocols and standards
may include different definitions of channels. Furthermore, some
standards may define and use multiple types of channels, e.g.,
different channels for uplink or downlink and/or different channels
for different uses such as data, control information, etc.
[0044] Band--The term "band" has the full breadth of its ordinary
meaning, and at least includes a section of spectrum (e.g., radio
frequency spectrum) in which channels are used or set aside for the
same purpose.
[0045] Automatically--refers to an action or operation performed by
a computer system (e.g., software executed by the computer system)
or device (e.g., circuitry, programmable hardware elements, ASICs,
etc.), without user input directly specifying or performing the
action or operation. Thus the term "automatically" is in contrast
to an operation being manually performed or specified by the user,
where the user provides input to directly perform the operation. An
automatic procedure may be initiated by input provided by the user,
but the subsequent actions that are performed "automatically" are
not specified by the user, i.e., are not performed "manually",
where the user specifies each action to perform. For example, a
user filling out an electronic form by selecting each field and
providing input specifying information (e.g., by typing
information, selecting check boxes, radio selections, etc.) is
filling out the form manually, even though the computer system must
update the form in response to the user actions. The form may be
automatically filled out by the computer system where the computer
system (e.g., software executing on the computer system) analyzes
the fields of the form and fills in the form without any user input
specifying the answers to the fields. As indicated above, the user
may invoke the automatic filling of the form, but is not involved
in the actual filling of the form (e.g., the user is not manually
specifying answers to fields but rather they are being
automatically completed). The present specification provides
various examples of operations being automatically performed in
response to actions the user has taken.
FIGS. 1 and 2--Communication System
[0046] FIG. 1 illustrates an exemplary (and simplified) wireless
communication system. It is noted that the system of FIG. 1 is
merely one example of a possible system, and embodiments of the
disclosure may be implemented in any of various systems, as
desired.
[0047] As shown, the exemplary wireless communication system
includes a base station 102 which communicates over a transmission
medium with one or more user devices 106A, 106B, etc., through
106N. Each of the user devices may be referred to herein as a "user
equipment" (UE). Thus, the user devices 106 are referred to as UEs
or UE devices.
[0048] The base station 102 may be a base transceiver station (BTS)
or cell site, and may include hardware that enables wireless
communication with the UEs 106A through 106N. If the base station
102 is implemented in the context of LTE, it may alternately be
referred to as an `eNodeB`. The base station 102 may also be
equipped to communicate with a network 100 (e.g., a core network of
a cellular service provider, a telecommunication network such as a
public switched telephone network (PSTN), and/or the Internet,
among various possibilities). Thus, the base station 102 may
facilitate communication between the user devices and/or between
the user devices and the network 100.
[0049] The communication area (or coverage area) of the base
station may be referred to as a "cell." The base station 102 and
the UEs 106 may be configured to communicate over the transmission
medium using any of various radio access technologies (RATs),
wireless communication technologies, or telecommunication
standards, such as GSM, UMTS (WCDMA, TD-SCDMA), LTE, LTE-Advanced
(LTE-A), 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi,
WiMAX etc.
[0050] Base station 102 and other similar base stations operating
according to the same or a different cellular communication
standard may thus be provided as a network of cells, which may
provide continuous or nearly continuous overlapping service to UEs
106A-N and similar devices over a wide geographic area via one or
more cellular communication standards.
[0051] Thus, while base station 102 may act as a "serving cell" for
UEs 106A-N as illustrated in FIG. 1, each UE 106 may also be
capable of receiving signals from (and possibly within
communication range of) one or more other cells (which might be
provided by other base stations), which may be referred to as
"neighboring cells". Such cells may also be capable of facilitating
communication between user devices and/or between user devices and
the network 100. Such cells may include "macro" cells, "micro"
cells, "pico" cells, and/or cells which provide any of various
other granularities of service area size. Other configurations are
also possible.
[0052] Note that a UE 106 may be capable of communicating using
multiple wireless communication standards. For example, a UE 106
might be configured to communicate using two or more of GSM, UMTS,
CDMA2000, WiMAX, LTE, LTE-A, WLAN, Bluetooth, one or more global
navigational satellite systems (GNSS, e.g., GPS or GLONASS), one
and/or more mobile television broadcasting standards (e.g.,
ATSC-M/H or DVB-H), etc. Other combinations of wireless
communication standards (including more than two wireless
communication standards) are also possible.
[0053] FIG. 2 illustrates user equipment 106 (e.g., one of the
devices 106A through 106N) in communication with a base station
102. The UE 106 may be a device with cellular communication
capability such as a mobile phone, a hand-held device, a computer
or a tablet, or virtually any type of wireless device.
[0054] The UE 106 may include a processor that is configured to
execute program instructions stored in memory. The UE 106 may
perform any of the method embodiments described herein by executing
such stored instructions. Alternatively, or in addition, the UE 106
may include a programmable hardware element such as an FPGA
(field-programmable gate array) that is configured to perform any
of the method embodiments described herein, or any portion of any
of the method embodiments described herein.
[0055] In some embodiments, the UE 106 may be configured to
communicate using any of multiple RATs. For example, the UE 106 may
be configured to communicate using two or more of GSM, UMTS,
CDMA2000, LTE, LTE-A, WLAN, or GNSS. Other combinations of wireless
communication technologies are also possible.
[0056] The UE 106 may include one or more antennas for
communicating using one or more wireless communication protocols or
technologies. In one embodiment, the UE 106 might be configured to
communicate using either of CDMA2000 (1xRTT/1xEV-DO/HRPD/eHRPD) or
LTE using a single shared radio and/or GSM or LTE using the single
shared radio. The shared radio may couple to a single antenna, or
may couple to multiple antennas (e.g., for MIMO) for performing
wireless communications. In general, a radio may include any
combination of a baseband processor, analog RF signal processing
circuitry (e.g., including filters, mixers, oscillators,
amplifiers, etc.), or digital processing circuitry (e.g., for
digital modulation as well as other digital processing). Similarly,
the radio may implement one or more receive and transmit chains
using the aforementioned hardware. For example, the UE 106 may
share one or more parts of a receive and/or transmit chain between
multiple wireless communication technologies, such as those
discussed above.
[0057] In some embodiments, the UE 106 may include separate
transmit and/or receive chains (e.g., including separate antennas
and other radio components) for each wireless communication
protocol with which it is configured to communicate. As a further
possibility, the UE 106 may include one or more radios which are
shared between multiple wireless communication protocols, and one
or more radios which are used exclusively by a single wireless
communication protocol. For example, the UE 106 might include a
shared radio for communicating using either of LTE or 1xRTT (or LTE
or GSM), and separate radios for communicating using each of Wi-Fi
and Bluetooth. Other configurations are also possible.
FIG. 3--Exemplary Block Diagram of a UE
[0058] FIG. 3 illustrates an exemplary block diagram of a UE 106.
As shown, the UE 106 may include a system on chip (SOC) 300, which
may include portions for various purposes. For example, as shown,
the SOC 300 may include processor(s) 302 which may execute program
instructions for the UE 106 and display circuitry 304 which may
perform graphics processing and provide display signals to the
display 360. The SOC 300 may also include motion sensing circuitry
370 which may detect motion of the UE 106, for example using a
gyroscope, accelerometer, and/or any of various other motion
sensing components. The processor(s) 302 may also be coupled to
memory management unit (MMU) 340, which may be configured to
receive addresses from the processor(s) 302 and translate those
addresses to locations in memory (e.g., memory 306, read only
memory (ROM) 350, NAND flash memory 310) and/or to other circuits
or devices, such as the display circuitry 304, wireless
communication circuitry 330, connector I/F 320, and/or display 360.
The MMU 340 may be configured to perform memory protection and page
table translation or set up. In some embodiments, the MMU 340 may
be included as a portion of the processor(s) 302.
[0059] As shown, the SOC 300 may be coupled to various other
circuits of the UE 106. For example, the UE 106 may include various
types of memory (e.g., including NAND flash 310), a connector
interface 320 (e.g., for coupling to a computer system, dock,
charging station, etc.), the display 360, and wireless
communication circuitry (e.g., radio) 330 (e.g., for LTE, Wi-Fi,
GPS, etc.).
[0060] The UE device 106 may include at least one antenna, and in
some embodiments multiple antennas, for performing wireless
communication with base stations and/or other devices. For example,
the UE device 106 may use antenna 335 to perform the wireless
communication. As noted above, the UE 106 may be configured to
communicate wirelessly using multiple wireless communication
standards in some embodiments.
[0061] As described further subsequently herein, the UE 106 may
include hardware and software components for implementing features
for throttling attempts to transition to connected mode based on
device motion, such as those described herein with reference to,
inter alia, FIG. 5. The processor 302 of the UE device 106 may be
configured to implement part or all of the methods described
herein, e.g., by executing program instructions stored on a memory
medium (e.g., a non-transitory computer-readable memory medium). In
other embodiments, processor 302 may be configured as a
programmable hardware element, such as an FPGA (Field Programmable
Gate Array), or as an ASIC (Application Specific Integrated
Circuit). Alternatively (or in addition) the processor 302 of the
UE device 106, in conjunction with one or more of the other
components 300, 304, 306, 310, 320, 330, 335, 340, 350, 360 may be
configured to implement part or all of the features described
herein, such as the features described herein with reference to,
inter alia, FIG. 5.
FIG. 4--Exemplary Block Diagram of a Base Station
[0062] FIG. 4 illustrates an exemplary block diagram of a base
station 102. It is noted that the base station of FIG. 4 is merely
one example of a possible base station. As shown, the base station
102 may include processor(s) 404 which may execute program
instructions for the base station 102. The processor(s) 404 may
also be coupled to memory management unit (MMU) 440, which may be
configured to receive addresses from the processor(s) 404 and
translate those addresses to locations in memory (e.g., memory 460
and read only memory (ROM) 450) or to other circuits or
devices.
[0063] The base station 102 may include at least one network port
470. The network port 470 may be configured to couple to a
telephone network and provide a plurality of devices, such as UE
devices 106, access to the telephone network as described above in
FIGS. 1 and 2.
[0064] The network port 470 (or an additional network port) may
also or alternatively be configured to couple to a cellular
network, e.g., a core network of a cellular service provider. The
core network may provide mobility related services and/or other
services to a plurality of devices, such as UE devices 106. In some
cases, the network port 470 may couple to a telephone network via
the core network, and/or the core network may provide a telephone
network (e.g., among other UE devices serviced by the cellular
service provider).
[0065] The base station 102 may include at least one antenna 434,
and possibly multiple antennas. The at least one antenna 434 may be
configured to operate as a wireless transceiver and may be further
configured to communicate with UE devices 106 via radio 430. The
antenna 434 communicates with the radio 430 via communication chain
432. Communication chain 432 may be a receive chain, a transmit
chain or both. The radio 430 may be configured to communicate via
various wireless telecommunication standards, including, but not
limited to, LTE, LTE-A, UMTS, CDMA2000, Wi-Fi, etc.
[0066] The BS 102 may be configured to communicate wirelessly using
multiple wireless communication standards. In some instances, the
base station 102 may include multiple radios, which may enable the
base station 102 to communicate according to multiple wireless
communication technologies. For example, as one possibility, the
base station 102 may include an LTE radio for performing
communication according to LTE as well as a Wi-Fi radio for
performing communication according to Wi-Fi. In such a case, the
base station 102 may be capable of operating as both an LTE base
station and a Wi-Fi access point. As another possibility, the base
station 102 may include a multi-mode radio which is capable of
performing communications according to any of multiple wireless
communication technologies (e.g., LTE and Wi-Fi, LTE and UMTS, LTE
and CDMA2000, UMTS and GSM, etc.).
[0067] As described further subsequently herein, the BS 102 may
include hardware and software components for implementing or
supporting implementation of features described herein. The
processor 404 of the base station 102 may be configured to
implement or support implementation of part or all of the methods
described herein, e.g., by executing program instructions stored on
a memory medium (e.g., a non-transitory computer-readable memory
medium). Alternatively, the processor 404 may be configured as a
programmable hardware element, such as an FPGA (Field Programmable
Gate Array), or as an ASIC (Application Specific Integrated
Circuit), or a combination thereof. Alternatively (or in addition)
the processor 404 of the BS 102, in conjunction with one or more of
the other components 430, 432, 434, 440, 450, 460, 470 may be
configured to implement or support implementation of part or all of
the features described herein.
FIG. 5--Flowchart
[0068] FIG. 5 is a flowchart diagram illustrating a method for a UE
device 106 to enable and disable connected-mode transition
procedure (e.g., RACH) throttling based at least partially on
device motion. The method shown in FIG. 5 may be used in
conjunction with any of the computer systems or devices shown in
the above Figures, among other devices. In various embodiments,
some of the method elements shown may be performed concurrently, in
a different order than shown, or may be omitted. Additional method
elements may also be performed as desired. As shown, this method
may operate as follows.
[0069] In 502, the UE may camp on a ("first") serving cell. The UE
may utilize any of various wireless communication technologies to
camp on the serving cell. For example, the serving cell may operate
according to any of GSM, UMTS, LTE, CDMA2000 (1xRTT, HRPD), etc.
The cell may accordingly be provided by a base station 102 and may
provide a connection to a core network, e.g., of a cellular service
provider. The base station 102 may operate in conjunction with
numerous other base stations (which may provide other cells) and
other network hardware and software to provide continuous (or
nearly continuous) overlapping wireless service over a wide
geographic area.
[0070] In addition to the serving cell, there may also be one or
more "neighboring" cells, provided by nearby base stations, within
communication range of the UE 106. The UE 106 may be capable of
discovering, detecting signals from, and possibly communicating
with such neighbor cells, but may not have an active wireless link
with them.
[0071] The UE 106 may camp on the first cell in an idle mode. The
idle mode may be used when the UE 106 is not actively exchanging
data (e.g., as part of a call or a networking application such as a
web browser) with the network. In a 3GPP context, the idle mode may
be a radio resource control idle mode or RRC idle mode (e.g., in
contrast to an RRC connected mode or state). 3GPP2 and/or other
contexts are also possible. As part of the idle mode, the UE 106
may utilize a "discontinuous reception" or "DRX" technique. In DRX,
a UE 106 may generally be inactive (e.g., with one or more
components, such as radio and/or baseband components, powered down
or sleeping) except for a (often relatively short) temporal window
of activity during each DRX cycle. The active portion of a DRX
cycle may be scheduled in a regular periodic manner; for example,
many networks schedule the active portion of DRX cycles to occur at
1.28 s intervals, or at some multiple of 1.28 s (e.g., 2.56 s, 5.12
s, etc). Other values for DRX periodicity (e.g., 0.32 s, 0.64 s,
etc.) may be used as desired.
[0072] During the active portion of a DRX cycle, the UE 106 may
perform certain actions according to the configuration of the UE
106 and/or according to the configuration information received from
the network. For example, the UE 106 may monitor a paging channel
for incoming voice calls or data during the active portion of the
DRX cycle. Information indicating the length and/or other
characteristics of the DRX cycle may be provided by the network to
the UE 106 as part of configuration information, in order to
facilitate coordinated operation between the UE 106 and the
network. Cell searches and measurements may also be performed in
the active portion of at least some DRX cycles.
[0073] In 504, the UE 106 may attempt to transition the UE 106 from
the idle mode to a connected mode. For example, the UE 106 may
attempt a random access channel (RACH) procedure (e.g., in 3GPP
contexts) or send an "OpenConnection" command (e.g., in 3GPP2
contexts). Transitioning from the idle mode to the connected mode
may include acquiring synchronization and/or establishing
communication channels and/or radio links which provide access to
more extensive network resources (e.g., data carrying channels
and/or greater uplink/downlink bandwidth) to the UE 106.
[0074] The connected mode transition procedure may be initiated
based on the presence of data to be transmitted (e.g., mobile
originated data/signaling) at the UE 106, for example from a
networking application executing at the UE 106. The procedure may
be used to set initial power for any signaling or data messages
(e.g., depending on path loss). Note that in some instances, a RACH
procedure may also be used for connection recovery (i.e., a
connected-mode RACH) in addition to or instead of for idle to
connected mode transitions (i.e., an idle-mode RACH).
[0075] The procedure may include any of various steps. As one
possibility, the UE 106 may initiate a RACH procedure by
transmitting a physical random access channel (PRACH) preamble
("MSG1"). The network (by way of the serving cell) may respond with
a random access response ("RAR" or "MSG2") acknowledging the PRACH
preamble. The UE 106 may follow up with an RRC connection request
("MSG3"). The network may respond to (acknowledge with a "MSG4")
the RRC connection request to complete the RACH procedure. In the
case that all messages in this message sequence between the UE 106
and the network are successfully exchanged, the RACH procedure may
be successful and the UE 106 may be in the connected mode. Note
that other RACH procedures (e.g., involving different numbers
and/or types of steps, etc.) are also possible, as are other types
of procedures for transitioning from idle- to connected-mode.
[0076] It may also be possible for an attempted transition to
connected mode to fail. For example, if no response is received by
the UE 106 to a PRACH preamble within a specific (e.g.,
configurable) duration, a RACH procedure may have failed. As
another possibility, if no response to a RRC connection request is
received within a specific duration, the RACH procedure may
likewise have failed. In such cases, the UE 106 may attempt another
RACH procedure, for example by re-transmitting the PRACH preamble
with an incrementally increased transmit power relative to the
previous attempt. Similarly, repeated attempts to transition to
connected mode may be made according to other techniques for
transitioning, in some instances.
[0077] This process (e.g., successive RACH attempts with
incrementally increased transmit power) may generally repeat until
one or more conditions for stopping further connected mode
transition attempts is met. One such condition may of course be
that such a procedure is successful. Other possible conditions
might include reaching a specified maximum number of PRACH attempts
(e.g., in UMTS), or upon expiration of a timer (e.g., a T300 timer
in LTE).
[0078] Further possible conditions for stopping or throttling
further attempts relating to a motion state may also be used. The
technique of repeating connected mode transition procedure attempts
with incrementally increased power after an unsuccessful attempt
may be reasonably likely to result in eventual success if a UE 106
is moving, since for example the movement of the UE 106 may result
in changing RF conditions and a corresponding potential for
improvement in serving cell strength/quality and/or re-selection to
a different serving cell with better strength/quality. However, if
the UE 106 is stationary and repeated failures on the serving cell
of the UE 106 occur, there may be a limited likelihood that further
connected mode transition procedure attempts will be successful,
since for example as long as the UE 106 is stationary the
likelihood of substantial change in serving cell signal
strength/quality (or re-selection to a different serving cell) may
be relatively low.
[0079] Accordingly, in order to support motion state based
connected mode transition throttling techniques (among various
other possible reasons), in 506, a motion state of the UE 106 may
be determined. The state of motion of the UE 106 may be either
`stationary` or `non-stationary`, as two possibilities. For
example, if motion above a motion threshold is detected, the UE 106
may be determined to be non-stationary, while if motion detected is
below the motion threshold, the UE 106 may be determined to be
non-stationary. Other (e.g., intermediate) states of motion may be
defined if desired.
[0080] The motion detection may be performed by motion sensing
circuitry of the UE 106. For example, the UE 106 may include one or
more accelerometers, gyroscopes, vibration sensors, and/or other
motion sensing components, which may be capable of sensing motion
magnitude and type for various types of motion.
[0081] In 508, connected mode transition throttling may be enabled
if a predetermined number of (e.g., most recent) attempts have
failed, and if the UE 106 is stationary. The throttling may be
enabled for up to a prescribed period of time. The throttling may
include preventing the UE 106 from initiating any attempts to
transition to the connected mode for mobile originated data or
signaling.
[0082] Alternatively, or in addition, in 510, the UE 106 may be
barred from the serving cell for up to a prescribed period of time
if a predetermined number of attempts to transition to connected
mode have failed, and if the UE 106 is stationary. Barring the UE
106 from the serving cell may include preventing the UE 106 from
camping on that cell (which may indirectly prevent or throttle
further attempts to transition to connected mode on that cell). A
cell may be barred by preventing camping specifically on the cell
based on its cell id, or more generically by preventing camping on
the frequency on which the cell is deployed, and/or by preventing
attaching to the network (PLMN) to which the cell belongs, among
various possibilities. Note that the requisite number of failed
attempts and/or the prescribed period of time for barring a cell
may be the same as or different than the requisite number of failed
attempts and/or the prescribed period of time for enabling
throttling of attempts to transition to connected mode, as
desired.
[0083] Such motion (or lack-of-motion) based connected mode
transition throttling and/or cell barring may also be contingent on
one or more other conditions, if desired. As one possible example,
one or more user activity indicators may be monitored. For example,
a display status may be an indicator of user activity: if the
display is on, this may be an indication of a higher user activity
level (e.g., one or more foreground apps may be running), while if
the display is off (or on because of a notification rather than
user activity), this may be an indication of a lower user activity
level. In some instances, such throttling and/or cell barring may
not be enabled even if the UE 106 is stationary and the required
threshold number of most recent attempts to transition to connected
mode have failed to do so, if user activity indicators are in a
state indicative of high user activity. Said another way,
throttling further connected mode transition attempts for up to the
prescribed period of time may also be contingent upon one or more
user activity indicators being in a state indicative of low user
activity. Thus, the throttling feature may at least in some
instances be considered "user context aware" or "user context
sensitive", where the user context may include the state of motion
of the UE 106, screen activity level, and/or any of various other
aspects of user context may be considered when deciding whether to
enable or disable the throttling feature.
[0084] As another possible consideration, how recently the UE 106
has performed cell selection or re-selection may be monitored. For
example, the UE 106 may determine when a most recent cell selection
or re-selection occurred. If the UE 106 has selected or re-selected
to its current serving cell during the period of time in which the
predetermined number of connected mode transition attempt failures
occurred (e.g., if one or more of the failed attempts occurred on a
different cell), connected mode transition throttling and/or cell
barring may not (yet) be enabled. In other words, throttling
further attempts to transition to connected mode or barring the
serving cell may also be contingent upon no cell selections or
re-selections having occurred during the connected mode transition
procedure attempts being considered to fulfill the threshold number
of failed connected mode transition attempts.
[0085] Once the prescribed period of time expires, the UE 106 may
disable the connected mode transition throttling feature and/or
unbar the cell which had been barred. In this case, the UE 106 may
no longer be prevented from initiating any connected mode
transition attempts and/or camping on the previously barred cell.
It should be noted that, at least in some instances, the UE 106 may
not necessarily immediately attempt to transition to connected mode
or camp on the previously barred cell upon connected mode
transition throttling being disabled or unbarring of the previously
barred cell, but if any new mobile originated data/signaling is
generated or re-selection to that cell otherwise occurs, UE 106 may
not be prevented from proceeding.
[0086] In certain circumstances, the UE 106 may disable connected
mode transition throttling and/or unbar a cell prior to expiration
of the prescribed period of time. For example, if the UE 106 ceases
to be stationary, connected mode transition throttling may be
disabled and/or a previously barred cell may be unbarred, even if
the prescribed period of time has not yet expired. As another
example, if the UE re-selects to a different serving cell,
connected mode transition throttling may be disabled. As a further
possibility, if the serving cell signal strength and/or signal
quality (e.g,. RSRP/RSRQ/RSCP/EcNo/etc., depending on a RAT
according to which the serving cell operates) change (e.g.,
improve) by at least a certain threshold, connected mode transition
throttling may be disabled; similarly, if signal strength and/or
signal quality of a barred cell change (e.g., improve) by at least
a certain threshold, that cell may be unbarred. As a still further
possibility, if user activity indicators change to a state
indicative of high user activity prior to expiration of the
prescribed period of time, connected mode transition throttling may
be disabled and/or a previously barred cell may be unbarred prior
to expiration of the prescribed period of time.
[0087] In some instances, connected mode transition throttling
and/or cell barring based on device motion may progress in an
increasingly aggressive loop if further time goes by after the
initial prescribed period of connected mode transition throttling
and/or cell barring in which the UE 106 continues to be stationary
and still further connected mode transition attempt failures
occur.
[0088] For example, if the UE 106 is still stationary after
expiration of the initial prescribed period of time, and if another
(potentially different, for example smaller) threshold number of
successive connected mode transition attempts have failed on the
same serving cell, connected mode transition throttling may again
be enabled and/or the cell may again be barred for a further
(potentially different, for example longer) prescribed period of
time. As one such possibility, in the first iteration of such a
loop, the requisite number of connected mode transition failures
might be five, and the prescribed period of time might be two
minutes. In the second iteration of such a loop, the requisite
number of connected mode transition failures might be three, and
the prescribed period of time might be five minutes. Further
iterations may further increase in aggressiveness, or stabilize at
a maximum aggressiveness level, as desired. In other words, the
method may be an iterative or multi-stage process, where the number
of connected mode transition failures required to trigger cell
barring or connected mode transition throttling may decrease with
each iteration, and the period of time for which a cell is barred
or connected mode transitions are throttled may increase with each
iteration. In some instances, such a multi-stage algorithm may be
implemented with learning capability, such that the features of
each stage may be modified in accordance with increasing knowledge
and/or experience with individual user behavior with respect to a
particular UE 106. Such a loop or multi-stage process may be exited
once a successful connected mode transition procedure is completed,
if desired.
[0089] In at least some instances, the UE 106 may also re-select to
another serving cell based at least in part on barring of its
previous serving cell or connected mode transition throttling being
enabled. For example, since the UE 106 may previously have been
camping on a cell on which camping is now barred, the UE 106 may be
forced to re-select to a new cell. In some instances, the UE 106
may additionally have previously barred and/or throttled connected
mode transition attempts on one or more cells within range of the
UE 106. In such a case, the UE 106 may monitor or track which cells
are barred and/or on which cells connected mode transition attempt
throttling has been enabled, and may select a cell on which camping
is not barred and/or on which throttling of connected mode
transition attempts is not enabled to which to re-selects. In some
instances (e.g., if the UE 106 has mobile originated data or
signaling to communicate), once the UE 106 is camping on a new
cell, the UE 106 may perform one or more connected mode transition
attempts on the new serving cell. This may not be prevented since
the attempts may not be performed on a barred cell, and/or
re-selecting to a new cell may trigger disabling of the connected
mode transition throttling feature.
[0090] Thus, the method of FIG. 5 may provide techniques for a UE
106 to enable and disable connected mode transition throttling
and/or cell barring/unbarring based at least partially on device
motion (or lack thereof). This may allow the UE 106 to realize
power consumption reductions by avoiding performing further
connected mode transition attempts on a cell on which further
connected mode transition attempts are unlikely to be more
successful, e.g., due to the stationary state of the UE 106. Such
techniques may potentially also improve (or at least not
substantially reduce) service quality, for example by facilitating
more rapid cell re-selection to a cell on which connected mode
transition attempts may be successful in at least some
circumstances.
[0091] Note that the connected mode transition throttling feature
and the cell barring feature described herein may be applied
independently or together, as desired, and for either or both of
signaling and data connected mode transition attempts.
Additionally, it may be the case that either or both of these
features may be used in conjunction with any or all of various
RATs, including but not limited to GSM, UMTS (WCDMA, TDS-CDMA),
CDMA2000 (1xRTT, 1xEV-DO, HRPD, eHRPD), LTE, etc.
[0092] Note further that these features may be internally
configured (e.g., as part of device design/operating algorithm(s))
or configured by the network to which the UE 106 is attached.
Furthermore, any of the various thresholds and parameters (e.g.,
requisite number(s) of connected mode transition failures to enable
connected mode transition throttling and/or cell barring,
prescribed period(s) of time for such connected mode transition
throttling and/or cell barring, etc.) described herein may likewise
be either internally configured or provided by the network (e.g.,
as configuration parameter values), among various possibilities. If
configured or provided by the network, any of various means of
configuring such features and/or parameters may be used; for
example, such information may be provided in one or more
information elements in one or more configuration messages (e.g.,
RRC configuration messages), broadcast in one or more system
information blocks (SIBs), and/or provided in any of various other
ways, as desired.
FIG. 6--Exemplary RACH Procedure
[0093] FIG. 6 is a signal flow diagram illustrating an exemplary
idle-mode RACH procedure such as might be performed between a UE
106 and a network 100 according to LTE. It should be noted while
the exemplary details illustrated in and described with respect to
FIG. 6 may be representative of one possible connected mode
transition procedure technique, other techniques for transitioning
from idle to connected mode (e.g., according to other RATs) are
also possible. Accordingly, the features of FIG. 6 are not intended
to be limiting to the disclosure as a whole: numerous variations
and alternatives to the details provided herein below are possible
and should be considered within the scope of the disclosure.
[0094] A RACH may be a contention-based procedure for acquiring
synchronization and establishing communication channels and/or
radio links which provide access to more extensive network
resources (e.g., data carrying channels and/or greater
uplink/downlink bandwidth)
[0095] As shown, in 602 the UE 106 may transmit a first message to
the network 100. The first message ("Msg1") may include a RACH
preamble, including a random access radio network temporary
identifier (RA-RNTI).
[0096] In 604, the UE 106 may receive a second message from the
network 100. The second message ("Msg2", also referred to as
"random access response" or "RAR") may include a timing advance
(TA) parameter, a temporary cell radio network temporary identifier
(TC-RNTI), and an uplink grant for transmitting a third
message.
[0097] In 606, the UE 106 may transmit the third message to the
network 100. The third message ("Msg3", also referred to as "RRC
connection request") may include the TC-RNTI and a system
architecture evolution temporary mobile subscriber identity
(S-TMSI) to identify the UE 106 to the network 100.
[0098] In 608, the UE 106 may receive a fourth message from the
network 100. The fourth message ("Msg4" or "contention resolution
message") may promote the TC-RNTI to a cell radio network temporary
identifier (C-RNTI). The C-RNTI may be used for subsequent
connected-mode RACH attempts, among various uses, as desired.
[0099] Upon completion of the four message sequence, the UE 106 may
be in a connected mode (e.g., RRC connected) with the network 100,
and may perform network data exchange via its serving cell.
[0100] Embodiments of the present disclosure may be realized in any
of various forms. For example some embodiments may be realized as a
computer-implemented method, a computer-readable memory medium, or
a computer system. Other embodiments may be realized using one or
more custom-designed hardware devices such as ASICs. Still other
embodiments may be realized using one or more programmable hardware
elements such as FPGAs.
[0101] In some embodiments, a non-transitory computer-readable
memory medium may be configured so that it stores program
instructions and/or data, where the program instructions, if
executed by a computer system, cause the computer system to perform
a method, e.g., any of a method embodiments described herein, or,
any combination of the method embodiments described herein, or, any
subset of any of the method embodiments described herein, or, any
combination of such subsets.
[0102] In some embodiments, a device (e.g., a UE 106) may be
configured to include a processor (or a set of processors) and a
memory medium, where the memory medium stores program instructions,
where the processor is configured to read and execute the program
instructions from the memory medium, where the program instructions
are executable to implement any of the various method embodiments
described herein (or, any combination of the method embodiments
described herein, or, any subset of any of the method embodiments
described herein, or, any combination of such subsets). The device
may be realized in any of various forms.
[0103] Although the embodiments above have been described in
considerable detail, numerous variations and modifications will
become apparent to those skilled in the art once the above
disclosure is fully appreciated. It is intended that the following
claims be interpreted to embrace all such variations and
modifications.
* * * * *