U.S. patent application number 14/590883 was filed with the patent office on 2016-07-07 for assignment of mobility classifications to mobile devices.
The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Rajat Prakash, Damanjit Singh, Yeliz Tokgoz.
Application Number | 20160198372 14/590883 |
Document ID | / |
Family ID | 54850286 |
Filed Date | 2016-07-07 |
United States Patent
Application |
20160198372 |
Kind Code |
A1 |
Singh; Damanjit ; et
al. |
July 7, 2016 |
ASSIGNMENT OF MOBILITY CLASSIFICATIONS TO MOBILE DEVICES
Abstract
A method for enhancing assignment of mobility classifications to
mobile devices is described. A plurality of mobility
classifications are stored in association with a plurality of
mobile devices to indicate, for each mobile device, one or more
handover parameters used by the mobile device. One or more handover
parameters associated with the plurality of mobility
classifications are updated based on mobility events. An error
determination is made that one or more of the one or more mobile
devices are incorrectly associated with the mobility
classifications based on the one or more updated handover
parameters for the plurality of mobility classifications. In
response to the error determination, one or more new criteria are
established that adjust how the mobility classifications are
assigned.
Inventors: |
Singh; Damanjit; (San Diego,
CA) ; Prakash; Rajat; (San Diego, CA) ;
Tokgoz; Yeliz; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Family ID: |
54850286 |
Appl. No.: |
14/590883 |
Filed: |
January 6, 2015 |
Current U.S.
Class: |
455/436 |
Current CPC
Class: |
H04W 36/245 20130101;
H04W 36/0083 20130101; H04W 36/14 20130101; H04W 88/08
20130101 |
International
Class: |
H04W 36/00 20060101
H04W036/00; H04W 36/24 20060101 H04W036/24; H04W 36/14 20060101
H04W036/14 |
Claims
1. A method for enhancing assignment of mobility classifications to
mobile devices, the method comprising: storing a plurality of
mobility classifications in association with one or more mobile
devices, wherein the mobility classifications indicate, for each
mobile device, one or more handover parameters used by the mobile
device; updating the one or more handover parameters associated
with the plurality of mobility classifications based on mobility
events; making an error determination that at least one of the one
or more mobile devices is erroneously associated with the mobility
classifications based on the one or more updated handover
parameters for the plurality of mobility classifications; and
establishing, in response to the error determination, one or more
new criteria that adjust how the mobility classifications are
assigned.
2. The method of claim 1, wherein storing the plurality of mobility
classifications comprises storing a first mobility classification
in association with a first subset of the one or more mobile
devices and a second mobility classification in association with a
second subset of the one or more mobile devices.
3. The method of claim 2, wherein the first mobility classification
comprises a non-ping-pong user classification and the second
mobility classification comprises a ping-pong user
classification.
4. The method of claim 2, further comprising, prior to making the
error determination: applying one or more initial criteria to the
mobile devices; and associating the first subset with the first
mobility classification and the second subset with the second
mobility classification based on results of applying the one or
more initial criteria.
5. The method of claim 4, wherein a previous serving cells history
exists in association with each of the mobile devices, wherein each
previous serving cells history comprises data regarding one or more
previous serving cells of the mobile device, and wherein applying
the one or more initial criteria comprises: analyzing the previous
serving cells histories to identify one or more mobile devices that
have a certain repetition of one or more serving cells in a certain
number of previous serving cells; and assigning the second mobility
classification to each mobile device that has the certain
repetition of one or more serving cells in the certain number of
previous serving cells.
6. The method of claim 5, wherein a previous serving cells history
of a mobile device comprises user equipment (UE) History
Information.
7. The method of claim 5, wherein the one or more new criteria
relate to one or more of: more repetition of one or more serving
cells in a certain number of cell changes; less repetition of one
or more serving cells in a certain number of cell changes; a higher
ratio of repetition of one or more serving cells in the previous
serving cells history; a lower ratio of repetition of one or more
serving cells in the previous serving cells history; or
combinations thereof.
8. The method of claim 5, further comprising assigning the first
mobility classification to each mobile device that does not have
repetition of a serving cell in the certain number of previous
cells.
9. The method of claim 2, further comprising, prior to making the
error determination: receiving data regarding communication of the
one or more mobile devices with base stations; and analyzing the
data to identify mobility events and ping-pong handovers.
10. The method of claim 9, further comprising, prior to making the
error determination: storing a first initial set of handover
parameters that influence management of handovers of the first
subset between the base stations; and storing a second initial set
of handover parameters that influence management of handovers of
the second subset between the base stations.
11. The method of claim 10, further comprising storing, in response
to identifying the at least one event, at least one of: a first new
set of handover parameters that supplements or replaces the first
initial set of handover parameters to influence management of
handovers of the first subset between the base stations; a second
new set of handover parameters that supplements or replaces the
second initial set of handover parameters to influence management
of handovers of the second subset between the base stations; or
combinations thereof.
12. The method of claim 11, wherein making the error determination
comprises: comparing the first new set of handover parameters with
the first initial set of handover parameters to conclude that the
first new set of handover parameters is less permissive of
handovers between the base stations than the first initial set of
handover parameters; and determining, in response to the
conclusion, that one or more mobile devices of the first subset are
erroneously associated with the first mobility classification.
13. The method of claim 11, wherein making the error determination
comprises: comparing the second new set of handover parameters with
the second initial set of handover parameters to conclude that the
second new set of handover parameters is more permissive of
handovers between the base stations than the second initial set of
handover parameters; and determining, in response to the
conclusion, that one or more mobile devices of the second subset
are erroneously associated with the second mobility
classification.
14. The method of claim 11, wherein making the error determination
comprises: comparing the first new set of handover parameters with
the second new set of handover parameters to observe a reduction in
difference between at least one handover parameter of the first new
set of handover parameters and at least one handover parameter of
the second new set of handover parameters; and determining, in
response to the observation, that one or more mobile devices of the
first subset are erroneously associated with the first mobility
classification or one or more mobile devices of the second subset
are erroneously associated with the second mobility
classification.
15. The method of claim 2, wherein making the error determination
comprises determining that one or more mobile devices of the first
subset are erroneously associated with the first mobility
classification, wherein, compared with one or more initial criteria
used to assign the second mobility classification to the second
subset, the one or more new criteria facilitate assignment of the
second mobility classification to the one or more mobile
devices.
16. The method of claim 2, wherein making the error determination
comprises determining that one or more mobile devices of the second
subset are erroneously associated with the second mobility
classification, wherein, compared with one or more initial criteria
used to assign the first mobility classification to the first
subset, the one or more new criteria facilitate assignment of the
first mobility classification to the one or more mobile
devices.
17. The method of claim 2, wherein making the error determination
further comprises determining that one or more mobile devices of
the first subset are erroneously associated with the first mobility
classification and one or more mobile devices of the second subset
are erroneously associated with the second mobility classification,
wherein, compared with one or more initial criteria used to assign
the first mobility classification to the first subset, the one or
more new criteria facilitate assignment of the first mobility
classification to the one or more mobile devices.
18. The method of claim 2, further comprising: storing the one or
more new criteria; and applying the one or more new criteria to
assign one of the first mobility classification and the second
mobility classification to the one or more mobile devices.
19. An apparatus for enhancing assignment of mobility
classifications to mobile devices, the apparatus comprising: a
memory configured to store a plurality of mobility classifications
in association with one or more mobile devices, wherein the
mobility classifications indicate, for each mobile device, one or
more handover parameters used by the mobile device; and a hardware
processor, communicatively coupled to the memory, configured to
perform the steps of: updating the one or more handover parameters
associated with the plurality of mobility classifications based on
mobility events; making an error determination that at least one of
the one or more mobile devices is erroneously associated with the
mobility classifications based on the one or more updated handover
parameters for the plurality of mobility classifications; and
establishing, in response to the error determination, one or more
new criteria that adjust how the mobility classifications are
assigned.
20. The apparatus of claim 19, wherein storing the plurality of
mobility classifications comprises storing a first mobility
classification in association with a first subset of the one or
more mobile devices and a second mobility classification in
association with a second subset of the one or more mobile
devices.
21. The apparatus of claim 20, wherein the hardware processor is
further configured to perform, prior to making the error
determination, the steps of: applying one or more initial criteria
to the mobile devices; and associating the first subset with the
first mobility classification and the second subset with the second
mobility classification based on results of applying the one or
more initial criteria.
22. The apparatus of claim 21, wherein a previous serving cells
history exists in association with each of the mobile devices,
wherein each previous serving cells history comprises data
regarding one or more previous serving cells of the mobile device,
and wherein applying the one or more initial criteria comprises:
analyzing the previous serving cells histories to identify one or
more mobile devices that have a certain repetition of one or more
serving cells in a certain number of previous serving cells; and
assigning the second mobility classification to each mobile device
that has the certain repetition of one or more serving cells in the
certain number of previous serving cells.
23. The apparatus of claim 22, wherein the one or more new criteria
relate to one or more of: more repetition of one or more serving
cells in a certain number of cell changes; less repetition of one
or more serving cells in a certain number of cell changes; a higher
ratio of repetition of one or more serving cells in the previous
serving cells history; a lower ratio of repetition of one or more
serving cells in the previous serving cells history; or
combinations thereof.
24. The apparatus of claim 22, wherein the hardware processor is
further configured to perform the step of assigning the first
mobility classification to each mobile device that does not have
repetition of a serving cell in the certain number of previous
cells such that one of the first mobility classification and the
second mobility classification is assigned to each of the one or
more mobile devices.
25. The apparatus of claim 20, wherein the hardware processor is
further configured to perform, prior to making the error
determination, the steps of: receiving data regarding communication
of the one or more mobile devices with base stations; and analyzing
the data to identify mobility events and ping-pong handovers.
26. The apparatus of claim 25, wherein the hardware processor is
further configured to perform, prior to making the error
determination, the steps of: storing a first initial set of
handover parameters that influence management of handovers of the
first subset between the base stations; and storing a second
initial set of handover parameters that influence management of
handovers of the second subset between the base stations.
27. The apparatus of claim 26, wherein the hardware processor is
further configured to perform the step of storing, in response to
identifying the at least one event, at least one of: a first new
set of handover parameters that supplements or replaces the first
initial set of handover parameters to influence management of
handovers of the first subset between the base stations; a second
new set of handover parameters that supplements or replaces the
second initial set of handover parameters to influence management
of handovers of the second subset between the base stations; or
combinations thereof.
28. The apparatus of claim 20, wherein the hardware processor is
further configured to perform the steps of: storing the one or more
new criteria; and applying the one or more new criteria to assign
one of the first mobility classification and the second mobility
classification to the one or more mobile devices.
29. An apparatus for enhancing assignment of mobility
classifications to mobile devices, the apparatus comprising: means
for storing a plurality of mobility classifications in association
with one or more mobile devices, wherein the mobility
classifications indicate, for each mobile device, one or more
handover parameters used by the mobile device; means for updating
the one or more handover parameters associated with the plurality
of mobility classifications based on mobility events; means for
making an error determination that at least one of the one or more
mobile devices is erroneously associated with the mobility
classifications based on the one or more updated handover
parameters for the plurality of mobility classifications; and means
for establishing, in response to the error determination, one or
more new criteria that adjust how the mobility classifications are
assigned.
30. A non-transitory computer-readable medium comprising codes for
causing a computer to: store a plurality of mobility
classifications in association with one or more mobile devices,
wherein the mobility classifications indicate, for each mobile
device, one or more handover parameters used by the mobile device;
update the one or more handover parameters associated with the
plurality of mobility classifications based on mobility events;
make an error determination that at least one of the one or more
mobile devices is erroneously associated with the mobility
classifications based on the one or more updated handover
parameters for the plurality of mobility classifications; and
establish, in response to the error determination, one or more new
criteria that adjust how the mobility classifications are assigned.
Description
TECHNICAL FIELD
[0001] This disclosure relates generally to the field of
communications and more specifically to systems and methods for
enhancing assignment of mobility classifications to mobile
devices.
BACKGROUND
[0002] Wireless communication systems are widely deployed to
provide various types of communication content such as, for
example, voice, data, and so on. Typical wireless communication
systems may be multiple-access systems capable of supporting
communication with multiple users by sharing available system
resources (e.g., bandwidth, transmission power, etc.). Examples of
such multiple-access systems may 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, and
the like. Additionally, the systems can conform to specifications
such as third generation partnership project (3GPP), 3GPP long-term
evolution (LTE), ultra-mobile broadband (UMB), evolution data
optimized (EV-DO), etc.
[0003] In any type of base station deployment, an active high-speed
mobile device may go through frequent handovers between adjacent
base stations. Additionally, even a stationary or slow-moving
mobile device can experience frequent handovers due to channel
fading if the mobile device is present at a location where pilot
signals from different base stations are about the same strength
(i.e., pilot pollution). These frequent handovers between base
stations are undesirable as they can cause packet losses, leading
to voice artifacts, packet delays, and/or poor user experience, as
well as increase signaling load at the base station and/or core
network. Thus, it is desirable to regulate frequent mobile device
handovers.
SUMMARY
[0004] The following presents a simplified summary of one or more
aspects of systems and methods for enhancing assignment of mobility
classifications to mobile devices. A mobility classification may be
a class or category into which one or more mobile devices may be
grouped based on shared qualities or characteristics that relate to
how a mobile device moves in a wireless communication system. The
shared qualities or characteristics may also relate to how a mobile
device interacts with other devices in the wireless communication
system as the mobile device moves about the wireless communication
system.
[0005] This summary is not an extensive overview of all
contemplated aspects, and is intended to neither identify key or
critical elements nor delineate the scope of any or all aspects
thereof. 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.
[0006] In general, the systems and methods disclosed herein provide
mechanisms for enhancing assignment of mobility classifications to
mobile devices. In one aspect, a method may include storing a
plurality of mobility classifications in association with one or
more mobile devices such that the mobility classifications
indicate, for each mobile device, one or more handover parameters
used by the mobile device. The method may further include updating
the one or more handover parameters associated with the plurality
of mobility classifications based on mobility events. The method
may further include making an error determination that at least one
of the one or more mobile devices is erroneously associated with
the mobility classifications based on the one or more updated
handover parameters for the plurality of mobility classifications.
The method may also include establishing, in response to the error
determination, one or more new criteria that adjust how the
mobility classifications are assigned.
[0007] Storing the plurality of mobility classifications may
comprise storing a first mobility classification in association
with a first subset of the one or more mobile devices and a second
mobility classification in association with a second subset of the
one or more mobile devices. The first mobility classification may
comprise a non-ping-pong user classification and the second
mobility classification may comprise a ping-pong user
classification.
[0008] The method may further comprise, prior to making the error
determination, applying one or more initial criteria to the mobile
devices, and associating the first subset with the first mobility
classification and the second subset with the second mobility
classification based on results of applying the one or more initial
criteria.
[0009] A previous serving cells history may exist in association
with each of the mobile devices. Each previous serving cells
history may comprise data regarding one or more previous serving
cells of the mobile device. Applying the one or more initial
criteria may comprise analyzing the previous serving cells
histories to identify one or more mobile devices that have a
certain repetition of one or more serving cells in a certain number
of previous serving cells, and assigning the second mobility
classification to each mobile device that has the certain
repetition of one or more serving cells in the certain number of
previous serving cells. The previous serving cells history of a
mobile device may comprise UE History Information.
[0010] The one or more new criteria may relate to more repetition
of one or more serving cells in a certain number of cell changes or
less repetition of one or more serving cells in a certain number of
cell changes. The one or more new criteria may also relate to a
higher ratio of repetition of one or more serving cells in the
previous serving cells history or a lower ratio of repetition of
one or more serving cells in the previous serving cells
history.
[0011] The method may further comprise assigning the first mobility
classification to each mobile device that is not assigned the
second mobility classification or does not have repetition of a
serving cell in the certain number of previous cells such that one
of the first mobility classification and the second mobility
classification is assigned to each of the one or more mobile
devices.
[0012] The method may comprise, prior to making the error
determination, receiving data regarding communication of the one or
more mobile devices with base stations, and analyzing the data to
identify mobility events and ping-pong handovers.
[0013] The method may further comprise, prior to making the error
determination, storing a first initial set of handover parameters
that influence management of handovers of the first subset between
the base stations, and storing a second initial set of handover
parameters that influence management of handovers of the second
subset between the base stations.
[0014] The method may further comprise storing, in response to
identifying the at least one event, at least one of a first new set
of handover parameters that supplements or replaces the first
initial set of handover parameters to influence management of
handovers of the first subset between the base stations, and a
second new set of handover parameters that supplements or replaces
the second initial set of handover parameters to influence
management of handovers of the second subset between the base
stations.
[0015] In one aspect, making the error determination may comprise
comparing the first new set of handover parameters with the first
initial set of handover parameters to conclude that the first new
set of handover parameters is less permissive of handovers between
the base stations than the first initial set of handover
parameters, and determining, in response to the conclusion, that
one or more mobile devices of the first subset are erroneously
associated with the first mobility classification.
[0016] In another aspect, making the error determination may
comprise comparing the second new set of handover parameters with
the second initial set of handover parameters to conclude that the
second new set of handover parameters is more permissive of
handovers between the base stations than the second initial set of
handover parameters, and determining, in response to the
conclusion, that one or more mobile devices of the second subset
are erroneously associated with the second mobility
classification.
[0017] In still another aspect, making the error determination may
comprise comparing the first new set of handover parameters with
the second new set of handover parameters to observe a reduction in
difference between at least one handover parameter of the first new
set of handover parameters and at least one handover parameter of
the second new set of handover parameters, and determining, in
response to the observation, that one or more mobile devices of the
first subset are erroneously associated with the first mobility
classification or one or more mobile devices of the second subset
are erroneously associated with the second mobility
classification.
[0018] In yet another aspect, making the error determination may
comprise determining that one or more mobile devices of the first
subset are erroneously associated with the first mobility
classification, wherein, compared with one or more initial criteria
used to assign the second mobility classification to the second
subset, the one or more new criteria facilitate assignment of the
second mobility classification to the one or more mobile
devices.
[0019] In another aspect, making the error determination may
comprise determining that one or more mobile devices of the second
subset are erroneously associated with the second mobility
classification, wherein, compared with one or more initial criteria
used to assign the first mobility classification to the first
subset, the one or more new criteria facilitate assignment of the
first mobility classification to the one or more mobile
devices.
[0020] In yet another aspect, making the error determination may
further comprise determining that one or more mobile devices of the
first subset are erroneously associated with the first mobility
classification and one or more mobile devices of the second subset
are erroneously associated with the second mobility classification,
wherein, compared with one or more initial criteria used to assign
the first mobility classification to the first subset, the one or
more new criteria facilitate assignment of the first mobility
classification to the one or more mobile devices.
[0021] The method may further comprise storing the one or more new
criteria, and applying the one or more new criteria to assign one
of the first mobility classification and the second mobility
classification to the one or more mobile devices. The revised
mobility classification criteria may more accurately classify
mobile devices going forward. If desired, further refinement of the
criteria may be undertaken via repetition of the steps set forth
above.
[0022] 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
[0023] FIG. 1 is a block diagram of an exemplary system that
facilitates regulation of frequent handovers between access
points;
[0024] FIG. 2 is a block diagram of an exemplary system that
facilitates regulation of frequent handovers between access points
according to one aspect;
[0025] FIGS. 3A and 3B are diagrams of exemplary systems in which
regulation of frequent handovers may be performed;
[0026] FIGS. 4A and 4B are flow charts of two aspects of exemplary
methodologies for regulating frequent handovers;
[0027] FIG. 5 is a block diagram of an exemplary system that
regulates frequent handovers;
[0028] FIG. 6 is a block diagram of an exemplary system that
enhances assignment of mobility classifications to mobile devices
according to one aspect;
[0029] FIG. 7 is a flow chart of one aspect of an exemplary
methodology for enhancing assignment of mobility classifications to
mobile devices;
[0030] FIG. 8 is a block diagram of an exemplary system that
enhances assignment of mobility classifications to mobile
devices;
[0031] FIG. 9 is a block diagram of an example wireless
communication system in accordance with various aspects set forth
herein;
[0032] FIG. 10 is an illustration of an example wireless network
environment that can be employed in conjunction with the various
systems and methods described herein;
[0033] FIG. 11 illustrates an example wireless communication
system, configured to support a number of devices, in which the
aspects herein can be implemented;
[0034] FIG. 12 is an illustration of an exemplary communication
system to enable deployment of small cells within a network
environment; and
[0035] FIG. 13 illustrates an example of a coverage map having
several defined tracking areas.
DETAILED DESCRIPTION
[0036] Various aspects are now described with reference to the
drawings. In the following description, for purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of one or more aspects. It may be
evident, however, that such aspect(s) may be practiced without
these specific details. In various aspects, systems and methods for
enhancing regulation of frequent handovers by mobile devices
between adjacent base stations are disclosed.
[0037] A mobile device can be called a system, device, subscriber
unit, subscriber station, mobile station, mobile, remote station,
mobile terminal, remote terminal, access terminal, user terminal,
terminal, communication device, user agent, user device, or user
equipment (UE). A mobile device may be a cellular telephone, a
satellite phone, a cordless telephone, a Session Initiation
Protocol (SIP) phone, a wireless local loop (WLL) station, a
personal digital assistant (PDA), a handheld device having wireless
connection capability, a tablet, a computing device, or other
processing devices connected via a wireless modem to one or more
base stations (BS) that provide cellular or wireless network access
to the mobile device.
[0038] A base station (BS) may be utilized for communicating with
mobile device(s). To supplement conventional base stations,
low-power base stations can be deployed to provide more robust
wireless coverage to mobile devices. For example, low-power base
stations may also be referred to as an access point, small-cell
node, femto node, a pico node, micro node, a Node B, evolved Node B
(eNB), home Node B (HNB) or home evolved Node B (HeNB),
collectively referred to as H(e)NB, femto nodes, femtocell nodes,
pico nodes, micro nodes, or some other terminology. These low-power
base stations can be deployed for incremental capacity growth,
richer user experience, in-building or other specific geographic
coverage, and/or the like. For example, a low-power base station
may transmit at a relatively low power as compared to a macro base
station associated with a wireless wide area network (WWAN). As
such, the coverage area of the low-power base station can be
substantially smaller than the coverage area of a macro base
station. In some configurations, such low-power base stations are
connected to the Internet via broadband connection (e.g., digital
subscriber line (DSL) router, cable or other modem, etc.), which
can provide the backhaul link to the mobile operator's network. In
this regard, low-power base stations are often deployed in homes,
offices, etc. without consideration of a current network
environment.
[0039] Generally, wireless multiple-access communication systems
may simultaneously support communication for multiple mobile
devices. Each mobile device may communicate with one or more base
stations via transmissions on forward and reverse links. The
forward link (or downlink) refers to the communication link from
base stations to mobile devices, and the reverse link (or uplink)
refers to the communication link from mobile devices to base
stations. Further, communications between mobile devices and base
stations may be established via single-input single-output (SISO)
systems, multiple-input single-output (MISO) systems,
multiple-input multiple-output (MIMO) systems, and so forth. In
addition, mobile devices can communicate with other mobile devices
(and/or base stations with other base stations) in peer-to-peer
wireless network configurations.
[0040] The techniques described herein may be used for various
wireless communication systems such as CDMA, TDMA, FDMA, OFDMA,
SC-FDMA, Wi-Fi carrier sense multiple access (CSMA), and other
systems. The terms "system" and "network" are often used
interchangeably. A CDMA system may implement a radio technology
such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc.
UTRA includes Wideband-CDMA (W-CDMA) and other variants of CDMA.
Further, cdma2000 covers IS-2000, IS-95, and IS-856 standards. A
TDMA system may implement a radio technology such as Global System
for Mobile Communications (GSM). An OFDMA system may implement a
radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile
Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE
802.20, Flash-OFDM.RTM., etc. UTRA and E-UTRA are part of Universal
Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution
(LTE) is a release of UMTS that uses E-UTRA, which employs OFDMA on
the downlink and SC-FDMA on the uplink. UTRA, E-UTRA, UMTS, LTE,
and GSM are described in documents from an organization named the
"3rd Generation Partnership Project" (3GPP). Additionally, cdma2000
and UMB are described in documents from an organization named the
"3rd Generation Partnership Project 2" (3GPP2). Further, such
wireless communication systems may additionally include
peer-to-peer (e.g., mobile-to-mobile) ad hoc network systems that
often use unpaired unlicensed spectrums, 802.xx wireless LAN,
BLUETOOTH, and any other short- or long-range wireless
communication techniques.
[0041] Various aspects or features will be presented in terms of
systems that may include a number of devices, components, modules,
and the like. It is to be understood and appreciated that the
various systems may include additional devices, components,
modules, etc., and/or may not include all of the devices,
components, modules, etc. discussed in connection with the figures.
A combination of these approaches may also be used.
[0042] FIG. 1 shows an exemplary wireless communication system 100.
System 100 includes a macro base station 102 that can provide one
or more devices with access to a wireless network, as well as a
plurality of small-cell nodes 104, 106, 108, 110, and 112, which
can also provide wireless network access over a backhaul link (not
shown) with a mobile network over a broadband Internet connection.
In one example, small-cell nodes 104, 106, 108, 110, and/or 112 can
include other types of low-power base stations, relay nodes,
devices (e.g., communicating in peer-to-peer or ad-hoc mode with
other devices), etc. Each small-cell node may form a small cell
(not shown in FIG. 1, but described in greater detail below in FIG.
9). Moreover, system 100 includes a mobile device 114 that may
communicate with one or more of the small-cell nodes 104 and/or 106
to receive wireless access to the mobile network.
[0043] In the depicted small-cell deployment, due to the small
coverage area of each small cell, an active high-velocity mobile
device 114 may go through frequent handovers between adjacent small
cells (e.g., small-cell nodes 104, 106, 108, 110, and 112).
Additionally, even a stationary or slow-moving mobile device 114
can experience frequent handovers due to channel fading if it is
present at a location where pilot signals from different small-cell
nodes are about the same strength (i.e., pilot pollution). These
frequent handovers between small cells are undesirable as they can
cause packet losses, leading to voice artifacts, packet delays,
and/or poor user experience, as well as increase signaling load at
the small-cell nodes and/or the core network. Thus, it may be
desirable to regulate such frequent mobile device handovers between
small cells.
[0044] Furthermore, frequent mobile device handovers may also occur
between larger cells and/or between larger cells and small cells.
For example, one or more mobile devices may communicate directly
with the base station 102 and an adjacent base station 102 (not
shown). Such mobile devices may experience frequent handovers
between the base stations 102 due to mobile device motion, pilot
pollution, or other causes as described above. Hence, it may also
be desirable to regulate frequent mobile device handovers between
larger base stations. The following description may describe
regulation of small-cell communications, but may be equally
applicable to other types of base stations.
[0045] FIG. 2 illustrates an exemplary system 200 for regulating
frequent mobile device handovers between adjacent access points.
System 200 includes an access point 202, which may be substantially
any low-power base station or macro base station, and can, in one
example, include one or more of small-cell nodes 104, 106, 108,
110, and/or 112 (FIG. 1), as described herein. In general, the
access point 202 may include a ping-pong handover determination
component 206, a mobility failure detection component 213, a mobile
device classification component 209, and a handover regulation
component 210. Each of the components will be described in greater
detail herein below.
[0046] The ping-pong handover determination component 206 may be
configured to determine whether the mobile device 114, which became
recently connected to the access point 202 as a result of handover
from an adjacent access point, is subject to a ping-pong handover.
Alternatively or additionally, the ping-pong handover determination
component 206 can be configured to determine whether the mobile
device 114, which is connected to the access point 202, but is in
the process of connecting to an adjacent access point as a result
of handover, is subject to a ping-pong handover.
[0047] In one aspect, to determine whether the mobile device 114
experiences a ping-pong handover, the component 206 of access point
202 may be configured to obtain a previous serving cells history
for a mobile device. For example, in UMTS/LTE systems, the previous
serving cells history may be obtained from "UE History Information"
information element (IE), which can be passed during the handovers
from the source cell to the target cell. This IE may contain
information for the cells (e.g., up to 16) that a mobile device has
been served by in active state prior to the target cell. For each
of these cells, this IE may contain cell identity, cell type (e.g.,
macro, femto, very small, small, medium, large, etc.), and the time
the mobile device stayed in that cell.
[0048] Having obtained the previous serving cells history, the
ping-pong handover determination component 206 may implement one or
more detection schemes for determining whether the mobile device
114 is subject to ping-pong handover. For example, the ping-pong
handover determination component 206 may first identify past
serving cells from the mobile device "UE History Information" IE.
For example, `Cell ID`/`PLMN identity` field in `Last Visited UTRAN
Cell Information` IE or `Last Visited E-UTRAN Cell Information` IE
can be used for this purpose. Then, component 206 may check one or
more of the following conditions: [0049] Condition 1--Check if the
last `n` handovers have happened between the cells, which are RF
neighbors of the current cell. The above condition takes care of
the scenarios in which mobile device 114 is at the edge of the two
small cells or present in a pilot pollution area as shown in FIG.
3A; and [0050] Condition 2--Check if in the last `n` handovers, the
cell identity of a cell has repeated `x` times.
[0051] The ping-pong handover determination component 206 may
classify handovers as ping-pong handovers if one or both of the
above conditions are met. Those of skill in the art will appreciate
that there may be other conditions that could be used to classify
handovers as ping-pong handovers.
[0052] The mobility failure detection component 213 may detect
mobility/connection failures. These mobility/connection failures
may be detected by Mobility
[0053] Robustness Optimization (MRO) as defined in 3GPP TS 36.300
Release 9 and onward. MRO may detect failures such as `Too Late
Handover,` `Too Early Handover,` and `Handover to Wrong Cell,` as
described in 3GPP TS 36.300.
[0054] The mobile device classification component 209 may assign a
mobility classification to each mobile device, such as the mobile
device 114. Thus, the mobile devices 114 that communicate on the
network may be grouped into multiple subsets, with one subset for
each mobility classification. In some examples, only two mobility
classifications may be used. These may include a first mobility
classification for mobile devices not experiencing ping-pong
handovers (a first subset of the mobile devices on the network),
and a second mobility classification for mobile devices
experiencing ping-pong handovers (a second subset of the mobile
devices on the network). These mobility classifications may be
termed a non-ping-pong user classification and a ping-pong user
classification, respectively.
[0055] These mobility classifications may be obtained from analysis
of previous serving cells history as described above, and may thus
reflect an expectation regarding the future performance of each
mobile device that communicates over the network. For example,
since the mobile devices of the second subset have exhibited
ping-pong handover in the past, they may be expected to experience
ping-pong handover in the future. Similarly, since the mobile
devices of the first subset have not exhibited ping-pong handover
in the past, they may not be expected to experience ping-pong
handover in the future.
[0056] The mobile device classification component 209 may be used
to assign a mobility classification to the mobile device, based on
the determinations made by the ping-pong handover determination
component 206. As indicated previously, this may entail assignment
of one of two or more classes to the mobile device. In some
configurations, the mobility classifications may include a first
mobility classification for mobile devices that are not expected to
experience ping-pong handovers. The mobility classifications may
further include a second mobility classification for mobile devices
that are expected to experience ping-pong handovers. In other
configurations, more than two mobility classifications may be
assigned to the mobile devices.
[0057] Having classified the frequent handover (and thus, the
mobile device) as ping-pong handover, the access point 202 may use
handover regulation component 210 to regulate handover of the
mobile device 114. In one aspect, the component 210 may use the
following rules/actions based on the determination and
classification of frequent handovers.
[0058] If the historical handovers for a mobile device are
classified as `ping-pong handovers,` then access point 202 can make
handover more difficult between the ping-ponging (or neighboring)
cells, for this mobile device. This may be done by adjusting
handover parameters (parameters used for triggering handover
events) for the mobility classification applied to the mobile
device to make handovers more difficult. For example, in UMTS, one
way to achieve this would be by configuring handover parameters for
the mobile device differently in the `Measurement Control` message.
In another example, in LTE, one way to achieve this may be by
configuring handover parameters for the mobile device differently
in the `RRCConnectionReconfiguration` message. In certain
configurations, handover parameters may be governed by the
following inequalities, which may be applied to determine whether a
neighboring base station has become better (by at least an offset)
than the base station through which the mobile device is currently
communicating: [0059] Entering Condition:
Mn+Ofn+Ocn-Hys>Ms+Ofs+Ocs+Off [0060] Leaving Condition:
Mn+Ofn+Ocn+Hys<Ms+Ofs+Ocs+Off
[0061] Satisfaction of the inequality for a given time-to-trigger
(TTT) may determine whether handover occurs. For these
inequalities, the following definitions may apply: [0062]
Of=Frequency-Specific Offsets: -24 dB to +24 dB [0063]
M=Measurement of Cells [0064] Oc=Cell Individual Offset: -24 dB to
+24 dB [0065] Off=Event Offset: (-30 to +30)*0.5=-15 dB to +15 dB
[0066] Hys=Hysteresis: INTEGER (0 . . . 30)*0.5=0 dB to 15 dB
[0067] One or more values in the inequalities above may be adjusted
to restrict and/or delay handovers for mobile devices assigned to a
ping-pong handover classification. For example, increasing the
values of Hys and/or TTT parameters may delay triggering of
handover events to all small cells. As another example, a reported
range constant parameter may be used in addition to those set forth
above. As a further example, decreasing the value of the reported
range constant parameter may delay triggering of handover events to
small cells. As yet another example, decreasing the value of Oc
parameter for a small cell may decrease the delay in triggering
handover events for that small cell.
[0068] The inequalities set forth above are merely exemplary. In
other implementations, handover parameters may be different from
those set forth above. Such other handover parameters may include,
but are not limited to, measurement identity, event identity, event
type, event offset (such as Event A3 offset), measurement type,
reporting interval, amount of reporting, threshold, filter
coefficient, Use Oc, cells for measurement, compressed-mode
parameters, measurement gaps configuration, and frequency offset.
The above list of parameters is not exhaustive and other parameters
that trigger handover events both at the mobile device and access
point may be configured in other aspects.
[0069] If desired, access point 202 can delay handover to the cells
involved in ping-pong handovers. For example, after the mobile
device 114 triggers an event used to initiate handover to a new
small cell, the access point 202 may request that the mobile device
continue reporting that small cell for a longer-than-usual time to
determine whether handover will occur. However, if delaying
handovers to ping-ponging small cells does not work (e.g., frequent
handovers continue), inter-frequency handover to a macrocell may be
initiated by access point 202 as described above.
[0070] In addition, although FIG. 2 illustrates an access point 202
that may determine how mobility classifications are assigned (i.e.,
distributed self-organizing network (SON)), alternatively, the
mobility classifications could be determined at a network entity
(i.e., centralized or hybrid SON). In that scenario, the network
entity may communicate the mobility classification criteria to the
access point 202.
[0071] Referring now to FIG. 3B, in a pilot-pollution region 350
including multiple small-cell nodes 352, 354, 356, and 358,
handovers performed by either a stationary, slow-moving mobile
device 360 or fast-moving (e.g., vehicular) mobile device 362 may
be similar. This may lead to mobile devices 360, 362 being
misclassified. If a mobile device 362 is misclassified as a member
of the second mobility classification (e.g., as a ping-ponging
mobile device), the mobile device 362 may experience connection
failures due to restrictive handover parameters. If a mobile device
360 is misclassified as a member of the first mobility
classification (e.g., as a non-ping-ponging mobile device), it may
experience more ping-pong handovers and/or may even be sent to
another frequency/RAT layer (which may lead to loss of offload to
small cells).
[0072] Moreover, once the mobile device 362 leaves the pilot
pollution area 350, the mobile device 362 may experience connection
failures due to restrictive handover parameters applied to the
second mobility classification. Hence, the mobile device 362 may
more appropriately belong to the first subset, and should receive
the first mobility classification.
[0073] Even for mobile devices that that are being correctly
classified, misclassifications may still occur in the future.
Periodically, the metrics used to classify a mobile device, such as
those described in detail above, may need to be adjusted to
compensate for changes in network traffic, new network nodes, or
other changes. Accordingly, it would be beneficial to provide
systems and methods for detecting that one or more mobile devices
are misclassified, and performing one or more remedial steps to
correct the misclassification.
[0074] FIGS. 4A and 4B show exemplary methodologies for regulation
of frequent handovers between cells. While, for purposes of
simplicity of explanation, the methodology is shown and described
as a series of acts, it is to be understood and appreciated that
the methodology is not limited by the order of acts, as some acts
may, in accordance with one or more configurations, occur in
different orders and/or concurrently with other acts from that
shown and described herein. For example, it is to be appreciated
that a methodology could alternatively be represented as a series
of interrelated states or events, such as in a state diagram.
Moreover, not all illustrated acts may be required to implement a
methodology in accordance with one or more configurations.
[0075] Turning to FIG. 4A, an exemplary methodology 400 is
displayed that facilitates regulation of frequent handovers. In one
aspect, for example, methodology 400 may be defined in instructions
stored on an access point, such as access point 202, or one or more
components thereof, and executed by a processor to perform the
described acts. At block 402, an access point obtains previous
serving cells history information for a mobile device which became
recently connected to the access point as a result of handover from
an adjacent access point or which is connected to the access point
but is in the process of a potential handover to an adjacent access
point. In one aspect, the previous serving cells history
information can be obtained from the "UE History
Information"information element (IE), which can be passed during
the handovers from a source cell to a target cell. This IE may
contain information for the cells (e.g., up to 16) that a mobile
device has been served by in active state prior to the target cell.
For each of these cells, IE may contain cell identity, cell type
(e.g., macro, femto, very small, small, medium, large, etc.), and
the time the mobile device stayed in that cell.
[0076] At block 404, the access point determines, based on the
previous serving cells history, whether the mobile device is
subject to ping-pong handovers. At block 406, the access point may
determine, for a mobile device with frequent handovers, whether the
frequent handovers are ping-pong handovers. At block 407, the
access point may assign a mobility classification to the mobile
device. At block 408, the access point may select handover
regulation actions.
[0077] The handover regulation actions may be selected based on the
mobility classification assigned in the block 407. For example, if
the mobile device is assigned a mobility classification for mobile
devices that experience ping-pong handovers, then the access point
can make handover of this mobile device to the ping-ponging (or
neighboring) cells more difficult by, for example, adjusting
handover triggering parameters of the access point and/or mobile
device, as described previously. The access point may also increase
this difficulty level in steps, by adjusting handover-triggering
parameters of the access point and/or mobile device in steps.
Alternatively or additionally, the access point can delay handover
to the cells involved in ping-pong handovers. If the above
described frequent handover regulating actions do not work, then
the access point can initiate inter-frequency or inter-RAT handover
to a collocated macrocell, as a fallback option. In another
example, if handovers are classified as non-ping-pong handovers,
due to a slow-moving or stationary user, then the access point can
decide to not adjust handover parameters for this mobile device. In
yet another example, if handovers are classified as non-ping-pong
handovers, due to a fast moving user, then the access point can
make handover to neighboring cells easier for this mobile device by
adjusting handover-triggering parameters of the access point and/or
mobile device. Alternatively, the access point can initiate
inter-frequency or inter-RAT handover to a collocated macrocell for
this mobile device.
[0078] Once the appropriate initial handover parameters and/or
other regulating actions for each mobility classification have been
selected, they may be applied as the mobile devices of each subset
(i.e., each mobility classification) interact with the cells of the
network. The initial handover parameters may be used to govern how
handovers are managed among the cells. It may be helpful to update
the handover parameters periodically to further adjust and/or
optimize the handover parameters. Thus, the initial handover
parameters for each mobility classification may be replaced and/or
supplemented with new handover parameters that are adjusted to
provide better performance of the network. This may be done
iteratively, with each successive new set of handover parameters
replacing and/or supplementing the previously applied set of
handover parameters. This process may help the network adapt to
changing conditions among the mobile devices as will be shown and
described in connection with FIG. 4B.
[0079] Turning to FIG. 4B, another exemplary methodology 410 is
displayed that facilitates a multi-step regulation of frequent
handovers. In one aspect, for example, methodology 410 may be
defined in instructions stored on an access point, such as access
point 202, or one or more components thereof, and executed by a
processor to perform the described acts. At block 412, an access
point may monitor handovers (such as regular handovers, ping-pong
handovers, etc.) and/or mobility connection failures of a first
group of one or more mobile devices associated with a mobility
classification. The mobility/connection failures may be detected by
Mobility Robustness Optimization (MRO) as defined in 3GPP TS 36.300
Release 9 and onwards. MRO may detect failures such as `Too Late
Handover,` `Too Early Handover,` and `Handover to Wrong Cell.` At
block 414, the access point may adjust one or more handover
parameters associated with the mobility classification based on the
monitored handovers and/or mobility connection failures of the
first group, wherein the one or more handover parameters relate to
triggering handovers for mobile devices associated with the
mobility classification. The adjusted one or more handover
parameters may be communicated to a second group of one or more
mobile devices associated with the mobility classification. The
second group of one or more mobile devices may include one or more
of the one or more mobile devices in the first group and/or one or
more mobile devices connected to the access point that were not
part of the first group. Examples of parameter adjustments are
provided above.
[0080] At block 416, the access point may monitor handovers and/or
mobility connection failures of the second group. At block 418, the
access point may readjust the one or more handover parameters
associated with the mobility classification based on the monitored
handovers and/or mobility/connection failures of the second group.
The adjusted/readjusted handover parameters may include, but need
not be limited to, measurement identity, event identity, event
type, event offset (such as Event A3 offset), measurement type,
reporting interval, amount of reporting, threshold, hysteresis,
TTT, filter coefficient, CIO, use CIO, reporting range constant,
cells for measurement, compressed-mode parameters, frequency
offset, and/or any of the parameters listed previously in the
discussion of handover parameters.
[0081] FIG. 5 illustrates a system 500 for regulating frequent
handovers. For example, system 500 can reside at least partially
within an access point. It is to be appreciated that system 500 is
represented as including functional blocks, which can be functional
blocks that represent functions implemented by a processor,
software, or combination thereof (e.g., firmware). System 500
includes a logical grouping 502 of electrical components that can
act in conjunction. For instance, logical grouping 502 can include
an electrical component 504 for determining frequent handovers
using, for example, handover history of the mobile device. Further,
logical grouping 502 can include an electrical component 507 for
classifying mobile devices based on whether the mobile devices are
experiencing ping-pong handovers. Yet further, logical grouping 502
may include an electrical component 508 for regulating frequent
handover based on handover classification.
[0082] Additionally, system 500 can include a memory 512 that
retains instructions for executing functions associated with the
electrical components 504, 507, and 508. The memory 512 may
additionally or alternatively store mobility classifications
assigned by the electrical component 507. The mobility
classifications may be stored in association with the mobile
devices to which they pertain. According to one configuration, the
memory 512 may contain a database containing identifiers for the
mobile devices (such as an IMEI, MEID, MAC address, IP address, or
other unique hardware-based or software-based identifier) in
association with the mobility classifications. If desired, the
memory 512 may also contain other information such as the initial
classification criteria used to assign the mobility classifications
to the mobile devices, handover parameters applicable to each
mobility classification, and/or the like. While shown as being
external to memory 512, it is to be understood that one or more of
the electrical components 504, 507, and 508 can exist within memory
512.
[0083] In one example, electrical components 504, 507, and 508 can
define at least one processor, or each electrical component 504,
507, and 508 can be a corresponding module of at least one
processor. Moreover, in an additional or alternative example,
electrical components 504, 507, and 508 can be a computer-program
product stored on a computer-readable medium, where each electrical
component 504, 507, and 508 can be corresponding code.
[0084] Referring now to FIG. 6, a block diagram illustrates an
exemplary system 600 that enhances the assignment of mobility
classifications to mobile devices according to one aspect. System
600 includes an access point 202, which can be substantially any
macro base station or low-power base station, and can, in one
example, include one or more of small-cell nodes 104, 106, 108,
110, and/or 112 (FIG. 1), as described herein. The access point 202
may include various components, as shown in FIG. 6. These
components may be present in addition to those of FIG. 2; hence,
FIG. 6 is not intended to provide a complete listing of the
components of the access point 202. Rather, FIG. 6 illustrates only
the components that are designed to enhance the assignment of
mobility classifications to mobile devices via correction of mobile
device misclassification.
[0085] As shown in FIG. 6, the access point 202 includes a mobility
classification storage component 602, a handover parameter updating
component 604, an error determination component 606, and a new
criteria establishment component 608. Each of the components will
be described in greater detail herein below.
[0086] The mobility classification storage component 602 may store
a plurality of mobility classifications in association with one or
more mobile devices. The mobility classifications may indicate, for
each mobile device, one or more handover parameters used by the
mobile device.
[0087] The handover parameter updating component 604 may update the
one or more handover parameters associated with the plurality of
mobility classifications based on mobility events as described in
the methodology of FIG. 4B.
[0088] The error determination component 606 may determine whether
any of the mobile devices have been misclassified (i.e.,
erroneously classified). This may be done, for example, via
analysis of the results of the handover parameter updating
component 604 as described in FIG. 4B. More specifically, as
mentioned previously, the methodology 410 of FIG. 4B may result in
the iterative establishment of new handover parameters for each
mobility classification that replace and/or supplement the previous
handover parameters for that mobility classification (i.e., the
initial handover parameters). The error determination component 606
may compare the new handover parameters with the initial handover
parameters for each mobility classification to determine whether
the new handover parameters are more or less handover-friendly than
the old handover parameters.
[0089] Because the methodology includes monitoring the operation of
the network (in the block 412 and the block 416) for problem
events, such as ping-pong handovers and mobility/connection
failures (e.g., `Too Late Handover,` `Too Early Handover,`
`Handover to Wrong Cell,` etc.), and adjusting the handover
parameters to reduce the incidence of such events, any change
occurring in the handover parameters pursuant to the operation of
the methodology 410 may be a signal of problems in the manner in
which handovers are being carried out. It may be assumed that at
least some of the problems detected by the methodology 410 are
caused by erroneous classification of mobile devices. The more
dramatic the change in handover parameters, the more mobile devices
in that mobility classification are likely to have been erroneously
classified.
[0090] Further, the manner in which the handover parameters are
changed pursuant to the methodology (i.e., whether the handover
parameters for that mobility classification have been adjusted to
be more handover-friendly or less handover-friendly) may indicate
whether that mobility classification has been assigned too
liberally or too sparingly to the mobile devices on the network.
Specifically, if the handover parameters for a non-ping-pong user
classification become more restrictive of handovers, it may be
assumed that at least some of the mobile devices that have been
assigned the non-ping-pong user classification should have a
ping-pong user classification. If the handover parameters for the
ping-pong user classification become less restrictive of handovers,
it may be assumed that at least some of the mobile devices that
have been assigned the ping-pong user classification should have
the non-ping-pong user classification.
[0091] For example, two mobility classifications may be used as
described previously: a first mobility classification for mobile
devices that are not expected to undergo ping-pong handovers, and a
second mobility classification for mobile devices that are expected
to undergo such ping-pong handovers. If the handover parameters for
the first mobility classification have been changed to become less
handover friendly (i.e., more restrictive of handovers), the error
determination component 606 may determine that one or more mobile
devices that have been assigned the first mobility classification
should have the second mobility classification. Conversely, if the
handover parameters for the second mobility classification have
been changed to become more handover friendly (i.e., less
restrictive of handovers), the error determination component 606
may determine that one or more mobile devices that have been
assigned the second mobility classification should have the first
mobility classification.
[0092] The existence of erroneous classification may be
particularly evident where the handover parameters of one mobility
classification have changed to become more like those of the other
mobility classification, and the handover parameters of the other
mobility classification have not changed significantly, or have
changed to become more distinct from those of the other mobility
classification. In such a case, it may be clear that the
misclassification is occurring primarily within the subset of
mobile devices for which the handover parameters have changed to
become more like those of the other mobility classification.
[0093] Conversely, where the handover parameters of both mobility
classifications have changed, it may not be clear which subset of
mobile devices has the preponderance of misclassified mobile
devices. Where there are only two mobility classifications, it may
then not be clear that either is over-inclusive.
[0094] As described above, the error determination component 606
may utilize the change in handover parameters caused by the
methodology 410 for each mobility classification of mobile devices
to determine the type and severity of a misclassification present
within the mobile devices connected to a network. Once this
information has been obtained, one or more remedial steps may be
taken. In one configuration, the classifications of mobile devices
perceived to be erroneously classified may be immediately corrected
in response to the error determination reached by the error
determination component 606. However, it may be difficult to know
exactly which mobile devices have been erroneously classified.
Furthermore, classification may typically happen when a mobile
device first connects to a base station (via startup connection or
handover). Thus, it may be easier to change the criteria applied to
classify mobile devices going forward, as handovers occur or mobile
devices are activated.
[0095] Thus, the new criteria establishment component 608 may
utilize the error determination made by the error determination
component 606 to establish new criteria for classifying mobile
devices. The new criteria may make it easier or more difficult to
assign a mobility classification to a mobile device. The new
criteria may help compensate for the misclassification as mobile
devices connect to base stations to receive mobility
classifications, and are classified under the new criteria.
[0096] Returning to the example of a first mobility classification
for mobile devices that are not expected to have ping-pong
handovers, and a second mobility classification for mobile devices
that are expected to have ping-pong handovers, the criteria (both
initial criteria and new criteria) applied to assign mobile devices
to the first mobility classification may be applied in the inverse
to assign mobile devices to the second mobility classification.
Since there are only two mobility classifications, all mobile
devices that do not meet the criteria for assignment to the first
mobility classification may receive the second mobility
classification. Additionally or alternatively, the criteria may
relate to assignment to the second mobility classification; thus,
all mobile devices that do not meet the criteria for inclusion in
the second mobility classification may receive the first mobility
classification.
[0097] If the handover parameters for the first mobility
classification have been changed to become less handover friendly
(i.e., more restrictive of handovers), the error determination
component 606 may determine that one or more mobile devices that
have been assigned the first mobility classification should have
the second mobility classification, as indicated above. The new
criteria establishment component 608 may then establish new
criteria that make it harder for mobile devices to be assigned the
first mobility classification, and easier for mobile devices to be
assigned the second mobility classification.
[0098] Conversely, if the handover parameters for the second
mobility classification have been changed to become more handover
friendly (i.e., less restrictive of handovers), the error
determination component 606 may determine that one or more mobile
devices that have been assigned the second mobility classification
should have the first mobility classification, as indicated above.
The new criteria establishment component 608 may then establish new
criteria that make it harder for mobile devices to be assigned the
second mobility classification, and easier for mobile devices to be
assigned the first mobility classification.
[0099] For the situation described above, in which the handover
parameters for the first mobility classification have been changed
to become less handover friendly and the handover parameters for
the second mobility classification have been changed to become more
handover friendly, it may not be clear which mobile devices are
erroneously classified. Thus, the new criteria establishment
component 608 may take action to facilitate handovers, effectively
moving the network toward a default state in which no action is
taken to regulate ping-pong handovers. Thus, the new criteria may
facilitate assignment of the mobile devices to the first mobility
classification. This action may at least facilitate handovers for
mobile devices that have been assigned to the second mobility
classification, but should instead be assigned to the first
mobility classification.
[0100] As mentioned previously, the analysis conducted by the error
determination component 606 may reveal the severity of the
misclassification. If desired, the new criteria establishment
component may utilize the severity of the misclassification to
determine how different the new criteria will be from the initial
criteria. Specifically, for a more severe misclassification, the
new criteria establishment component 608 may establish new criteria
that differ more dramatically from the initial criteria.
[0101] In the alternative, the new criteria establishment component
may instead utilize a uniform perturbation to differentiate the new
criteria from the initial criteria, regardless of the magnitude of
the misclassification. In such an event, future iterations may be
expected to establish further new criteria that progressively
depart from the initial criteria until the full extent of the
misclassification has been compensated for.
[0102] The new criteria may differ from the initial criteria in a
variety of ways. For example, as set forth in the description of
FIG. 2, a mobile device may be considered to be experiencing
ping-pong handovers, and thus be classified as a ping-pong user, if
one or more of the following conditions is met: [0103] Condition
1--Check if the last `n` handovers have happened between the cells,
which are RF neighbors of the current cell; and [0104] Condition
2--Check if in the last `n` handovers, the cell identity of a cell
has repeated `x` times.
[0105] If the new criteria are to make it easier for mobile devices
to be classified as ping-pong users, the value of `n` may be
decreased in the first condition. In another configuration, the
value of `x` may be decreased and/or the value of `n` may be
increased in the second condition. In other words, making it easier
for mobile devices to be classified as ping-pong users may relate
to requiring less repetition of one or more serving cells for a
certain number of cell changes or a lower ratio of repetition of
one or more serving cells in the previous serving cells
history.
[0106] If the new criteria are to make it more difficult for mobile
devices to be classified as ping-pong users, the value of `n` may
be increased in the first condition. In another configuration, the
value of `x` may be increased and/or the value of `n` may be
decreased in the second condition. In other words, making it more
difficult for mobile devices to be classified as ping-pong users
may relate to requiring more repetition of one or more serving
cells for a certain number of cell changes or a higher ratio of
repetition of one or more serving cells in the previous serving
cells history.
[0107] The foregoing examples relate to criteria by which mobile
devices may be assigned a ping-pong user classification. Those of
skill in the art will recognize that the criteria set forth above
may be easily restated such that meeting the criteria causes the
mobile device to be assigned a non-ping-pong user classification
(such as the first mobility classification in the
two-classification example provided previously), a ping-pong user
classification, or a mobility classification in between in the
event that more than two mobility classifications are used.
Further, those of skill in the art will recognize that a wide
variety of criteria different from those of the foregoing examples
may be applied to classify mobile devices within the scope of the
present disclosure. Thus, new criteria may differ from the initial
criteria in ways not specifically set forth herein, while still
accomplishing the objective of making it more or less difficult to
classify mobile devices as either more or less likely to experience
ping-pong handover.
[0108] Although the discussion of FIG. 6 focuses on the aspect in
which there are only two mobility classifications, the mobility
classification storage component 602, the handover parameter
updating component 604, the error determination component 606, and
the new criteria establishment component 608 may be used in aspects
in which there are more than two mobility classifications. The
mobility classification storage component 602, the handover
parameter updating component 604, error determination component
606, and the new criteria establishment component 608 may follow
steps similar to those set forth above. However, in such an aspect,
each mobility classification may have its own set of initial
criteria that are applied to determine whether mobile devices are
assigned to it. If desired, new criteria may be established for one
or more, but not all, of the mobility classifications (i.e., the
mobility classifications applied to misclassified mobile devices),
while the initial criteria are left intact and unmodified for one
or more of the mobility classifications (i.e., mobility
classifications applied to mobile devices for which there is little
or no misclassification).
[0109] In addition, although FIG. 6 illustrates an access point 202
that may determine how mobility classifications are assigned (i.e.,
distributed SON), alternatively, the mobility classifications could
be determined at a network entity (i.e., centralized or hybrid
SON). In that scenario, the network entity may communicate the
mobility classification criteria to the access point 202.
[0110] FIG. 7 is a flow chart of one aspect of an exemplary
methodology 700 for enhancing the assignment of mobility
classifications to mobile devices. Like the methodology 400 and the
methodology 410, methodology 700 may be defined in instructions
stored on an access point 202, or one or more components thereof,
and executed by a processor to perform the described acts.
[0111] At block 702, an apparatus may store a plurality of mobility
classifications in association with one or more mobile devices,
wherein the mobility classifications may indicate, for each mobile
device, one or more handover parameters used by the mobile device.
At block 704, the apparatus may update the one or more handover
parameters associated with the plurality of mobility
classifications based on mobility events.
[0112] At block 706, the apparatus may make an error determination
that at least one of the one or more mobile devices is erroneously
associated with the mobility classifications based on the one or
more updated handover parameters for the plurality of mobility
classifications. This determination may include analysis of the
data generated by the methodology 410, and more specifically,
comparison of the new handover parameters with the initial handover
parameters, for each mobility classification. The access point may
determine the direction and/or magnitude of the misclassification
for each subset of mobile devices. In the event that no significant
misclassifications are discovered, the methodology 700 may skip the
block 708 and end, until the next iteration.
[0113] At a block 708, the access point may establish, in response
to the error determination, one or more new criteria that adjust
how the mobility classifications are assigned to mobile devices.
The new criteria may be selected to compensate for any erroneous
classifications discovered in the block 706. This may be done as
set forth above, in the description of the new criteria
establishment component 608 of FIG. 6.
[0114] FIG. 8 is a block diagram of an exemplary system 800 that
enhances assignment of mobility classifications to mobile devices.
The system 800 can reside at least partially within an access point
202. It is to be appreciated that system 800 is represented as
including functional blocks, which can be functional blocks that
represent functions implemented by a processor, software, or
combination thereof (e.g., firmware). The system 800 includes a
logical grouping 802 of electrical components that can act in
conjunction. As shown, the logical grouping 802 may include: an
electrical component 804 for storing a plurality of mobility
classifications in association with one or more mobile devices,
wherein the mobility classifications indicate, for each mobile
device, one or more handover parameters used by the mobile device;
an electrical component 806 for updating the one or more handover
parameters associated with the plurality of mobility
classifications based on mobility events; an electrical component
808 for making an error determination that at least one of the one
or more mobile devices is erroneously associated with the mobility
classifications based on the one or more updated handover
parameters for the plurality of mobility classifications; and an
electrical component 804 for establishing, in response to the error
determination, one or more new criteria that adjust how the
mobility classifications are assigned.
[0115] The electrical component 802 may store a plurality of
mobility classifications in association with one or more mobile
devices as set forth in the description of the mobility
classification storage component 602 of FIG. 6.
[0116] The electrical component 804 may update the one or more
handover parameters associated with the plurality of mobility
classifications as set forth in the description of the handover
parameter updating component 604 of FIG. 6.
[0117] The electrical component 806 may make an error determination
that at least one of the one or more mobile devices is erroneously
associated with the mobility classifications as set forth in the
description of the error determination component 606 of FIG. 6.
[0118] The electrical component 808 may establish one or more new
criteria that adjust how the mobility classifications are assigned
as set forth above in the description of the new criteria
establishment component 608 of FIG. 6.
[0119] Additionally, system 800 can include a memory 812 that
retains instructions for executing functions associated with the
electrical components 804, 806, 808, and 810. The memory 812 may
additionally or alternatively store new criteria. The new criteria
may be stored in association with the mobility classifications to
which they pertain. If desired, the memory 510 may also contain
other information such as the initial classification criteria used
to assign the mobility classifications to the mobile devices,
handover parameters applicable to each mobility classification,
and/or the like. While shown as being external to memory 812, it is
to be understood that one or more of the electrical components 804,
806, 808, and 810 can exist within memory 812.
[0120] In one example, electrical components 804, 806, 808, and 810
can define at least one processor, or each electrical component
804, 806, 808, and 810 can be a corresponding module of at least
one processor. Moreover, in an additional or alternative example,
electrical components 804, 806, 808, and 810 can be a
computer-program product stored on a computer-readable medium,
where each electrical component 804, 806, 808, and 810 can be
corresponding code.
[0121] Referring now to FIG. 9, an exemplary wireless communication
system 900 is illustrated, in which mechanisms for regulation of
frequent handover may be implemented. System 900 includes a base
station 902, which may be a small-cell node, such as nodes 102 or
202, or system 500, and may include the components and implement
the functions described above with respect to FIGS. 1-8. In one
aspect, base station 902 can include multiple antenna groups. For
example, one antenna group can include antennas 904 and 906,
another group can comprise antennas 908 and 910, and an additional
group can include antennas 912 and 914. Two antennas are
illustrated for each antenna group; however, more or fewer antennas
can be utilized for each group. Base station 902 can additionally
include a transmitter chain and a receiver chain, each of which can
in turn comprise a plurality of components associated with signal
transmission and reception (e.g., processors, modulators,
multiplexers, demodulators, demultiplexers, antennas, etc.).
[0122] Base station 902 can communicate with one or more mobile
devices such as mobile device 916 and mobile device 922; however,
it is to be appreciated that base station 902 can communicate with
substantially any number of mobile devices similar to mobile
devices 916 and 922. Mobile devices 916 and 922 can be, for
example, cellular phones, smart phones, laptops, handheld
communication devices, handheld computing devices, satellite
radios, global positioning systems, PDAs, and/or any other suitable
device for communicating over wireless communication system 900. As
depicted, mobile device 916 is in communication with antennas 912
and 914, where antennas 912 and 914 transmit information to mobile
device 916 over a forward link 918 and receive information from
mobile device 916 over a reverse link 920. Moreover, mobile device
922 is in communication with antennas 904 and 906, where antennas
904 and 906 transmit information to mobile device 922 over a
forward link 924 and receive information from mobile device 922
over a reverse link 926. In a frequency division duplex (FDD)
system, forward link 918 can utilize a different frequency band
than that used by reverse link 920, and forward link 924 can employ
a different frequency band than that employed by reverse link 926,
for example. Further, in a time division duplex (TDD) system,
forward link 918 and reverse link 920 can utilize a common
frequency band and forward link 924 and reverse link 926 can
utilize a common frequency band.
[0123] Each group of antennas and/or the area in which they are
designated to communicate can be referred to as a sector of base
station 902. For example, antenna groups can be designed to
communicate to mobile devices in a sector of the areas covered by
base station 902. In communication over forward links 918 and 924,
the transmitting antennas of base station 902 can utilize
beamforming to improve signal-to-noise ratio of forward links 918
and 924 for mobile devices 916 and 922. Also, while base station
902 utilizes beamforming to transmit to mobile devices 916 and 922
scattered randomly through an associated coverage, mobile devices
in neighboring cells can be subject to less interference as
compared to a base station transmitting through a single antenna to
all its mobile devices. Moreover, mobile devices 916 and 922 can
communicate directly with one another using a peer-to-peer or ad
hoc technology as depicted. According to one example, system 900
can be a multiple-input multiple-output (MIMO) communication
system.
[0124] FIG. 10 shows an exemplary wireless communication system
1000. The wireless communication system 1000 depicts one base
station 1010, which can include a small-cell node, and one mobile
device 1050 for sake of brevity. However, it is to be appreciated
that system 1000 can include more than one base station and/or more
than one mobile device, wherein additional base stations and/or
mobile devices can be substantially similar or different from
example base station 1010 and mobile device 1050 described below.
In addition, it is to be appreciated that base station 1010 and/or
mobile device 1050 can employ the systems and/or methods described
herein to facilitate wireless communication there between. For
example, components or functions of the systems and/or methods
described herein can be part of a memory 1032 and/or 1072 or
processors 1030 and/or 1070 described below, and/or can be executed
by processors 1030 and/or 1070 to perform the disclosed
functions.
[0125] At base station 1010, traffic data for a number of data
streams is provided from a data source 1012 to a transmit (TX) data
processor 1014. According to an example, each data stream can be
transmitted over a respective antenna. TX data processor 1014
formats, codes, and interleaves the traffic data stream based on a
particular coding scheme selected for that data stream to provide
coded data.
[0126] The coded data for each data stream can be multiplexed with
pilot data using orthogonal frequency division multiplexing (OFDM)
techniques. Additionally or alternatively, the pilot symbols can be
frequency division multiplexed (FDM), time division multiplexed
(TDM), or code division multiplexed (CDM). The pilot data is
typically a known data pattern that is processed in a known manner
and can be used at mobile device 1050 to estimate channel response.
The multiplexed pilot and coded data for each data stream can be
modulated (e.g., symbol mapped) based on a particular modulation
scheme (e.g., binary phase-shift keying (BPSK), quadrature
phase-shift keying (QPSK), M-phase-shift keying (M-PSK),
M-quadrature amplitude modulation (M-QAM), etc.) selected for that
data stream to provide modulation symbols. The data rate, coding,
and modulation for each data stream can be determined by
instructions performed or provided by processor 1030.
[0127] The modulation symbols for the data streams can be provided
to a TX MIMO processor 1020, which can further process the
modulation symbols (e.g., for OFDM). TX MIMO processor 1020 then
provides N.sub.T modulation symbol streams to N.sub.T transmitters
(TMTR) 1022a through 1022t. In various aspects, TX MIMO processor
1020 applies beamforming weights to the symbols of the data streams
and to the antenna from which the symbol is being transmitted.
[0128] Each receiver 1022 receives and processes a respective
symbol stream to provide one or more analog signals, and further
conditions (e.g., amplifies, filters, and upconverts) the analog
signals to provide a modulated signal suitable for transmission
over the MIMO channel. Further, N.sub.T modulated signals from
transmitters 1022a through 1022t are transmitted from N.sub.T
antennas 1024a through 1024t, respectively.
[0129] At mobile device 1050, the transmitted modulated signals are
received by N.sub.R antennas 1052a through 1052r and the received
signal from each antenna 1052 is provided to a respective receiver
(RCVR) 1054a through 1054r. Each receiver 754 conditions (e.g.,
filters, amplifies, and downconverts) a respective signal,
digitizes the conditioned signal to provide samples, and further
processes the samples to provide a corresponding "received" symbol
stream.
[0130] An RX data processor 1060 can receive and process the
N.sub.R received symbol streams from N.sub.R receivers 1054 based
on a particular receiver processing technique to provide N.sub.T
"detected" symbol streams. RX data processor 1060 can demodulate,
deinterleave, and decode each detected symbol stream to recover the
traffic data for the data stream. The processing by RX data
processor 1060 is complementary to that performed by TX MIMO
processor 1020 and TX data processor 1014 at base station 1010.
[0131] The reverse link message can comprise various types of
information regarding the communication link and/or the received
data stream. The reverse link message can be processed by a TX data
processor 1038, which also receives traffic data for a number of
data streams from a data source 1036, modulated by a modulator
1080, conditioned by transmitters 1054a through 1054r, and
transmitted back to base station 1010.
[0132] At base station 1010, the modulated signals from mobile
device 1050 are received by antennas 1024, conditioned by receivers
1022, demodulated by a demodulator 1040, and processed by a RX data
processor 1042 to extract the reverse link message transmitted by
mobile device 1050. Further, processor 1030 can process the
extracted message to determine which precoding matrix to use for
determining the beamforming weights.
[0133] Processors 1030 and 1070 can direct (e.g., control,
coordinate, manage, etc.) operation at base station 1010 and mobile
device 1050, respectively. Respective processors 1030 and 1070 can
be associated with memory 1032 and 1072 that store program codes
and data. Processors 1030 and 1070 can also perform functionalities
described herein to support selecting a paging area identifier for
one or more access points.
[0134] FIG. 11 illustrates a wireless communication system 1100,
configured to support a number of users, in which the teachings
herein may be implemented. The system 1100 provides communication
for multiple cells 1102, such as, for example, macro cells
1102A-1102G, with each cell being serviced by a corresponding
access node 1104 (e.g., access nodes 1104A-1104G). As shown in FIG.
11, mobile devices 1106 (e.g., mobile devices 1106A-1106L) can be
dispersed at various locations throughout the system over time.
Each mobile device 1106 can communicate with one or more access
nodes 1104 on a forward link (FL) and/or a reverse link (RL) at a
given moment, depending upon whether the mobile device 1106 is
active and whether it is in soft handoff, for example. The wireless
communication system 1100 can provide service over a large
geographic region. In some aspects, some of the mobile devices
1106, such as devices 1106A, 1106H, and 1106J, may be small-cell
nodes, such as nodes 102 or 202 or system 500, and may include the
components and implement the functions described above with respect
to FIGS. 1-8.
[0135] FIG. 12 illustrates an exemplary communication system 1200
where one or more small-cell nodes are deployed within a network
environment. Specifically, the system 1200 includes multiple
small-cell nodes 1210A and 1210B (e.g., femtocell nodes or H(e)NB)
installed in a relatively small-scale network environment (e.g., in
one or more user residences 1230), which, in one aspect, may
correspond to small-cell nodes 104, 106, 108, 110, and 112 of FIGS.
1-8. Each small-cell node 1210 can be coupled to a wide area
network 1240 (e.g., the Internet) and a mobile operator core
network 1250 via a digital subscriber line (DSL) router, a cable
modem, a wireless link, or other connectivity means (not shown). As
will be discussed below, each small-cell node 1210 can be
configured to serve associated mobile devices 1220 (e.g., mobile
device 1220A) and, optionally, alien mobile devices 1220 (e.g.,
mobile device 1220B). In other words, access to small-cell nodes
1210 can be restricted such that a given mobile device 1220 can be
served by a set of designated (e.g., home) small-cell node(s) 1210
but may not be served by any non-designated small-cell nodes 1210
(e.g., a neighbor's small-cell node).
[0136] FIG. 13 illustrates an example of a coverage map 1300 where
several tracking areas 1302 (or routing areas or location areas)
are defined, each of which includes several macro coverage areas
1304. Here, areas of coverage associated with tracking areas 1302A,
1302B, and 1302C are delineated by the wide lines and the macro
coverage areas 1304 are represented by the hexagons. The tracking
areas 1302 also include femto coverage areas 1306 corresponding to
respective small-cell nodes, such as nodes 102 or 202 or system
500, and which may include the components and implement the
functions described above with respect to FIGS. 1-8. In this
example, each of the femto coverage areas 1306 (e.g., femto
coverage area 1306C) is depicted within a macro coverage area 1304
(e.g., macro coverage area 1304B). It should be appreciated,
however, that a femto coverage area 1306 may not lie entirely
within a macro coverage area 1304. In practice, a large number of
femto coverage areas 1306 can be defined with a given tracking area
1302 or macro coverage area 1304. Also, one or more pico coverage
areas (not shown) can be defined within a given tracking area 1302
or macro coverage area 1304.
[0137] Referring again to FIG. 12, the owner of a small-cell node
1210 can subscribe to mobile service, such as, for example, 3G
mobile service, offered through the mobile operator core network
1250. In another example, the small-cell node 1210 can be operated
by the mobile operator core network 1250 to expand coverage of the
wireless network. In addition, a mobile device 1220 can be capable
of operating both in macro environments and in smaller scale (e.g.,
residential) network environments. Thus, for example, depending on
the current location of the mobile device 1220, the mobile device
1220 can be served by a macro cell access node 1260 or by any one
of a set of small-cell nodes 1210 (e.g., the small-cell nodes 1210A
and 1210B that reside within a corresponding user residence 1230).
For example, when a subscriber is outside his home, he is served by
a standard macro cell access node (e.g., node 1260) and when the
subscriber is at home, he is served by a small-cell node (e.g.,
node 1210A). Here, it should be appreciated that a small-cell node
1210 can be backward compatible with existing mobile devices
1220.
[0138] A small-cell node 1210 can be deployed on a single frequency
or, in the alternative, on multiple frequencies. Depending on the
particular configuration, the single frequency or one or more of
the multiple frequencies can overlap with one or more frequencies
used by a macro cell access node (e.g., node 1260). In some
aspects, a mobile device 1220 can be configured to connect to a
preferred small-cell node (e.g., the home small-cell node of the
mobile device 1220) whenever such connectivity is possible. For
example, whenever the mobile device 1220 is within the user's
residence 1230, it can communicate with the home small-cell node
1210.
[0139] In some aspects, if the mobile device 1220 operates within
the mobile operator core network 1250 but is not residing on its
most preferred network (e.g., as defined in a preferred roaming
list), the mobile device 1220 can continue to search for the most
preferred network (e.g., small-cell node 1210) using a Better
System Reselection (BSR), which can involve a periodic scanning of
available systems to determine whether better systems are currently
available, and subsequent efforts to associate with such preferred
systems. Using an acquisition table entry (e.g., in a preferred
roaming list), in one example, the mobile device 1220 can limit the
search for specific band and channel. For example, the search for
the most preferred system can be repeated periodically. Upon
discovery of a preferred small-cell node, such as small-cell node
1210, the mobile device 1220 selects the small-cell node 1210 for
camping within its coverage area.
[0140] A small-cell node can be restricted in some aspects. For
example, a given small-cell node can only provide certain services
to certain mobile devices. In deployments with so-called restricted
(or closed) association, a given mobile device can only be served
by the macro cell mobile network and a defined set of small-cell
nodes (e.g., the small-cell nodes 1210 that reside within the
corresponding user residence 1230). In some implementations, a
small-cell node can be restricted to not provide, for at least one
mobile device, at least one of: signaling, data access,
registration, paging, or service.
[0141] In some aspects, a restricted small-cell node (which can
also be referred to as a Closed Subscriber Group H(e)NB) is one
that provides service to a restricted provisioned set of mobile
devices. This set can be temporarily or permanently extended as
necessary. In some aspects, a Closed Subscriber Group (CSG) can be
defined as the set of access nodes (e.g., small-cell nodes) that
share a common access control list of mobile devices. A channel on
which all small-cell nodes (or all restricted small-cell nodes) in
a region operate can be referred to as a femto channel.
[0142] Various relationships can thus exist between a given
small-cell node and a given mobile device. For example, from the
perspective of a mobile device, an open small-cell node can refer
to a small-cell node with no restricted association. A restricted
small-cell node can refer to a small-cell node that is restricted
in some manner (e.g., restricted for association and/or
registration). A home small-cell node can refer to a small-cell
node on which the mobile device is authorized to access and operate
on. A guest small-cell node can refer to a small-cell node on which
a mobile device is temporarily authorized to access or operate on.
An alien small-cell node can refer to a small-cell node on which
the mobile device is not authorized to access or operate on, except
for perhaps emergency situations (e.g., 911 calls).
[0143] From a restricted small-cell node perspective, a home mobile
device can refer to a mobile device that authorized to access the
restricted small-cell node. A guest mobile device can refer to a
mobile device with temporary access to the restricted small-cell
node. An alien mobile device can refer to a mobile device that does
not have permission to access the restricted small-cell node,
except for perhaps emergency situations, for example, 911 calls
(e.g., an access terminal that does not have the credentials or
permission to register with the restricted small-cell node).
[0144] For convenience, the disclosure herein describes various
functionality in the context of a small-cell node. It should be
appreciated, however, that a pico node can provide the same or
similar functionality as a small-cell node, but for a larger
coverage area. For example, a pico node can be restricted, a home
pico node can be defined for a given mobile device, and so on. The
present disclosure is also applicable to other base station types
besides small-cell nodes and pico nodes.
[0145] The systems and/or methodologies described herein are merely
exemplary; the systems and methodologies of the present disclosure
are not limited to any particular type of mobile device, base
station, or network, and may be used in conjunction with any type
of wireless communication technology.
[0146] The techniques described herein may be used for various
communication systems, including communication systems that are
based on an orthogonal multiplexing scheme. Examples of such
communication systems include Orthogonal Frequency Division
Multiple Access (OFDMA) systems, Single-Carrier Frequency Division
Multiple Access (SC-FDMA) systems, and so forth. An OFDMA system
utilizes orthogonal frequency division multiplexing (OFDM), which
is a modulation technique that partitions the overall system
bandwidth into multiple orthogonal sub-carriers. These sub-carriers
may also be called tones, bins, etc. With OFDM, each sub-carrier
may be independently modulated with data. An SC-FDMA system may
utilize interleaved FDMA (IFDMA) to transmit on sub-carriers that
are distributed across the system bandwidth, localized FDMA (LFDMA)
to transmit on a block of adjacent sub-carriers, or enhanced FDMA
(EFDMA) to transmit on multiple blocks of adjacent sub-carriers. In
general, modulation symbols are sent in the frequency domain with
OFDM and in the time domain with SC-FDMA.
[0147] In the above description, reference numbers have sometimes
been used in connection with various terms. Where a term is used in
connection with a reference number, this is meant to refer to a
specific element that is shown in one or more of the figures. Where
a term is used without a reference number, this is meant to refer
generally to the term without limitation to any particular
figure.
[0148] The term "determining" encompasses a wide variety of actions
and, therefore, "determining" can include calculating, computing,
processing, deriving, investigating, looking up (e.g., looking up
in a table, a database or another data structure), ascertaining and
the like. Also, "determining" can include receiving (e.g.,
receiving information), accessing (e.g., accessing data in a
memory) and the like. Also, "determining" can include resolving,
selecting, choosing, establishing, and the like.
[0149] The phrase "based on" does not mean "based only on," unless
expressly specified otherwise. In other words, the phrase "based
on" describes both "based only on" and "based at least on."
[0150] The term "processor" should be interpreted broadly to
encompass a generalpurpose processor, a central processing unit
(CPU), a microprocessor, a digital signal processor (DSP), a
controller, a microcontroller, a state machine, and so forth. Under
some circumstances, a "processor" may refer to an application
specific integrated circuit (ASIC), a programmable logic device
(PLD), a field programmable gate array (FPGA), etc. The term
"processor" may refer to a combination of processing devices, e.g.,
a combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0151] The term "memory" should be interpreted broadly to encompass
any electronic component capable of storing electronic information.
The term memory may refer to various types of processor-readable
media such as random access memory (RAM), read-only memory (ROM),
non-volatile random access memory (NVRAM), programmable read-only
memory (PROM), erasable programmable read-only memory (EPROM),
electrically erasable PROM (EEPROM), flash memory, magnetic or
optical data storage, registers, etc. Memory is said to be in
electronic communication with a processor if the processor can read
information from and/or write information to the memory. Memory
that is integral to a processor is in electronic communication with
the processor.
[0152] The terms "instructions" and "code" should be interpreted
broadly to include any type of computer-readable statement(s). For
example, the terms "instructions" and "code" may refer to one or
more programs, routines, sub-routines, functions, procedures, etc.
"Instructions" and "code" may comprise a single computer-readable
statement or many computer-readable statements.
[0153] The functions described herein may be implemented in
software or firmware being executed by hardware. The functions may
be stored as one or more instructions on a computer-readable
medium. The terms "computer-readable medium" or "computer-program
product" refers to any tangible storage medium that can be accessed
by a computer or a processor. By way of example, and not
limitation, a computer-readable medium may comprise RAM, ROM,
EEPROM, CD-ROM or other optical disk storage, magnetic disk storage
or other magnetic storage devices, or any other medium that may
carry or store desired program code in the form of instructions or
data structures and that can be accessed by a computer. Disk and
disc, as used herein, includes compact disc (CD), laser disc,
optical disc, digital versatile disc (DVD), floppy disk and
Blu-ray.RTM. disc where disks usually reproduce data magnetically,
while discs reproduce data optically with lasers. It should be
noted that a computer-readable medium may be tangible and
non-transitory. The term "computer-program product" refers to a
computing device or processor in combination with code or
instructions (e.g., a "program") that may be executed, processed,
or computed by the computing device or processor. As used herein,
the term "code" may refer to software, instructions, code, or data
that is/are executable by a computing device or processor.
[0154] Software or instructions may also be transmitted over a
transmission medium. For example, if the software is transmitted
from a website, server, or other remote source using a coaxial
cable, fiber optic cable, twisted pair, digital subscriber line
(DSL), or wireless technologies such as infrared, radio, and
microwave, then the coaxial cable, fiber optic cable, twisted pair,
DSL, or wireless technologies such as infrared, radio, and
microwave are included in the definition of transmission
medium.
[0155] The methods disclosed herein comprise one or more steps or
actions for achieving the described method. The method steps and/or
actions may be interchanged with one another without departing from
the scope of the claims. In other words, unless a specific order of
steps or actions is required for proper operation of the method
that is being described, the order and/or use of specific steps
and/or actions may be modified without departing from the scope of
the claims.
[0156] Further, it should be appreciated that modules and/or other
appropriate means for performing the methods and techniques
described herein can be downloaded and/or otherwise obtained by a
device. For example, a device may be coupled to a server to
facilitate the transfer of means for performing the methods
described herein. Alternatively, various methods described herein
can be provided via a storage means (e.g., random access memory
(RAM), read-only memory (ROM), a physical storage medium such as a
compact disc (CD) or floppy disk, etc.), such that a device may
obtain the various methods upon coupling or providing the storage
means to the device. Moreover, any other suitable technique for
providing the methods and techniques described herein to a device
can be utilized.
[0157] It is to be understood that the claims are not limited to
the precise configuration and components illustrated above. Various
modifications, changes, and variations may be made in the
arrangement, operation, and details of the systems, methods, and
apparatus described herein without departing from the scope of the
claims.
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