U.S. patent application number 12/033689 was filed with the patent office on 2009-01-22 for method and apparatus for inter-system handover.
This patent application is currently assigned to QUALCOMM Incorporated. Invention is credited to Rashid Ahmed Akbar Attar, Lorenzo Casaccia, Oronzo Flore, Francesco Grilli, Kirti Gupta, Durga Prasad Malladi, Nathan Edward Tenny.
Application Number | 20090023448 12/033689 |
Document ID | / |
Family ID | 39456455 |
Filed Date | 2009-01-22 |
United States Patent
Application |
20090023448 |
Kind Code |
A1 |
Attar; Rashid Ahmed Akbar ;
et al. |
January 22, 2009 |
METHOD AND APPARATUS FOR INTER-SYSTEM HANDOVER
Abstract
An inter-system handover system for a wireless communication
system supports hand-down and hand-up of user equipment (UE) to
different radio access technologies, including synchronous and
asynchronous systems. Latency and handover connection failures are
reduced by an access node (nodeB) broadcasting information about
neighboring systems (targets) when the UE reception (RX) capability
is both inside or outside the reception range of the target. A
single RX chain is sufficient, although transitioning between a
wireless wide area network (WWAN) to a wireless local area network
may (WLAN) may advantageously benefit from simultaneous operation
on two Rx chains. Optimized list of neighboring RAT systems
(targets) are broadcast from the network, including measurement
parameters and reporting instructions. Thereby, UE-driven reporting
minimizes latencies. UE reports other-system searches to network
only if needed for a handover. In addition, handover requests can
be bundled with other-system measurement information, if necessary,
for additional efficiencies.
Inventors: |
Attar; Rashid Ahmed Akbar;
(San Diego, CA) ; Malladi; Durga Prasad; (San
Diego, CA) ; Grilli; Francesco; (La Jolla, CA)
; Gupta; Kirti; (San Diego, CA) ; Casaccia;
Lorenzo; (Roma, IT) ; Tenny; Nathan Edward;
(Poway, CA) ; Flore; Oronzo; (Ostuni, IT) |
Correspondence
Address: |
QUALCOMM INCORPORATED
5775 MOREHOUSE DR.
SAN DIEGO
CA
92121
US
|
Assignee: |
QUALCOMM Incorporated
San Diego
CA
|
Family ID: |
39456455 |
Appl. No.: |
12/033689 |
Filed: |
February 19, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60891025 |
Feb 21, 2007 |
|
|
|
Current U.S.
Class: |
455/436 |
Current CPC
Class: |
H04W 36/38 20130101;
H04W 36/0061 20130101 |
Class at
Publication: |
455/436 |
International
Class: |
H04W 36/00 20090101
H04W036/00 |
Claims
1. A method for inter-system handovers in a wireless communication
system, comprising: transmitting a neighbor list from a source node
containing at least one parameter for connecting to a target node
proximal to a source node; transmitting a criterion for a user
equipment (UE) to determine when to pursue a handover to the target
node; and handing over the UE to the target node.
2. The method of claim 1, further comprising: transmitting the
neighbor list and criterion to the UE in idle mode; and removing
paging scheduled to the UE subsequent to a location update
acceptance by the target node.
3. The method of claim 1, further comprising transmitting the
neighbor list that identifies a subset of neighboring nodes for the
UE to search.
4. The method of claim 1, further comprising performing a handover
from a dual reception (Rx) chain UE utilizing a single Rx
chain.
5. The method of claim 1, wherein transmitting the criterion for
the UE to determine when to pursue the handover to the target node
further comprises transmitting information prompting the UE to
search for the target node.
6. The method of claim 5, further comprising transmitting
information comprising at least one target node in the neighbor
list to prompt a search.
7. The method of claim 6, further comprising transmitting
information that prompts the UE to search in response to a
determination that measured signal strength from the source node
has trended below a predetermined threshold.
8. The method of claim 1, further comprising transmitting the
criterion for requesting the handover by specifying measured power
parameter for the target system trending more than a predetermined
difference above a measured power parameter for the source
node.
9. The method of claim 8, further comprising specifying a
requirement that the measured power parameter for the source node
is determined to be below a specified threshold as prerequisite for
the UE to report satisfaction of the criterion for handover.
10. The method of claim 1, further comprising performing a load
based handover determination as a requirement for directing a
handover request determination.
11. The method of claim 1, further comprising performing generating
a flow composition based discontinuous reception (DRX) pattern.
12. The method of claim 1, further comprising transmitting the
neighbor list containing information that facilitates the handover
comprising a type identifier for a radio access technology, a
center frequency, and a system bandwidth.
13. The method of claim 1, further comprising transmitting the
neighbor list containing information comprising a reference time
difference between the source node and the target node.
14. The method of claim 1, further comprising transmitting the
neighbor list containing information comprising information
specific for a type of radio access technology.
15. At least one processor for inter-system handovers in a wireless
communication system, comprising: a first module for transmitting a
neighbor list from a source node containing at least one parameter
for connecting to a target node proximal to a source node; a second
module for transmitting a criterion for a user equipment (UE) to
determine when to pursue a handover to the target node; and a third
module for handing over the UE to the target node.
16. A computer program product for inter-system handovers in a
wireless communication system, comprising: a computer-readable
medium, comprising: a first set of codes for causing a computer to
transmit a neighbor list from a source node containing at least one
parameter for connecting to a target node proximal to a source
node; a second set of codes for causing the computer to transmit a
criterion for a user equipment (UE) to determine when to pursue a
handover to the target node; and a third set of codes for causing
the computer to hand over the UE to the target node.
17. An apparatus for inter-system handovers in a wireless
communication system, comprising: means for transmitting a neighbor
list from a source node containing at least one parameter for
connecting to a target node proximal to a source node; means for
transmitting a criterion for a user equipment (UE) to determine
when to pursue a handover to the target node; and means for handing
over the UE to the target node.
18. An apparatus for inter-system handovers in a wireless
communication system, comprising: a computer-readable medium
containing a data structure comprising a neighbor list from a
source node containing at least one parameter for connecting to a
target node proximal to a source node and containing a criterion
for a user equipment (UE) to determine when to pursue a handover to
the target node; a transmitter for transmitting the neighbor list
and criterion; and a communication channel to the target node for
facilitating handover of the UE to the target node.
19. The apparatus of claim 18, further comprising the transmitter
transmitting the neighbor list and criterion to the UE in idle
mode, and the communication channel facilitating handover by
removing paging scheduled to the UE subsequent to a location update
acceptance by the target node.
20. The apparatus of claim 18, further comprising the data
structure identifying a subset of neighboring nodes for the UE to
search.
21. The apparatus of claim 18, further comprising the transmitter
facilitating a handover from a dual reception (Rx) chain UE
utilizing a single Rx chain.
22. The apparatus of claim 18, wherein the criterion for the UE to
determine when to pursue the handover to the target node further
comprises information prompting the UE to search for the target
node.
23. The apparatus of claim 22, wherein the information prompting
the search comprises at least one target node in the neighbor list
to prompt a search.
24. The apparatus of claim 23, wherein the information that prompts
the UE to search comprises a requirement that measured signal
strength from the source node has trended below a predetermined
threshold.
25. The apparatus of claim 18, wherein the criterion for requesting
the handover specifies a measured power parameter for the target
system trending more than a predetermined difference above a
measured power parameter for the source node.
26. The apparatus of claim 25, further comprising the transmitter
transmitting a requirement that the measured power parameter from
the source node falls is determined to be below a specified
threshold as prerequisite for the UE to report satisfaction of the
criterion for handover.
27. The apparatus of claim 18, further comprising a processor
performing a load based handover determination as a requirement for
directing a handover request determination to be transmitted.
28. The apparatus of claim 18, further comprising a processor
generating preparing a flow composition based discontinuous
reception (DRX) pattern.
29. The apparatus of claim 18, wherein the neighbor list contains
information that facilitates the handover comprising a type
identifier for a radio access technology, a center frequency, and a
system bandwidth.
30. The apparatus of claim 18, wherein the neighbor list contains
information comprising a reference time difference between the
source node and the target node.
31. The apparatus of claim 18, wherein the neighbor list contains
information comprising information specific for a type of radio
access technology.
32. A method for inter-system handovers in a wireless communication
system, comprising: receiving a neighbor list from a source node
containing at least one parameter for connecting to a target node
proximal to a source node; receiving a criterion for a user
equipment (UE) to determine when to pursue a handover to the target
node; and requesting handing over to the target node.
33. The method of claim 32, further comprising: receiving the
neighbor list and criterion while in idle mode; and requesting a
location update request from the target node prompting a location
update acceptance by the target node.
34. The method of claim 32, further comprising receiving the
neighbor list that identifies a subset of neighboring nodes to
search.
35. The method of claim 32, further comprising searching for the
target node for a handover utilizing a single Rx chain of a dual
reception (Rx) chain.
36. The method of claim 32, wherein receiving the criterion to
determine when to pursue a handover to the target node further
comprises receiving information prompting the UE to search for the
target node.
37. The method of claim 36, further comprising receiving
information comprising at least one target node in the neighbor
list to prompt a search.
38. The method of claim 37, further comprising receiving
information that prompts the UE to search by making a determination
that measured signal strength from the source node has trended
below a predetermined threshold.
39. The method of claim 32, further comprising receiving the
criterion for requesting a handover that specifies measured power
parameter for the target system trending more than a predetermined
difference above a measured power parameter for the source
node.
40. The method of claim 39, further comprising reporting
satisfaction of the criterion for handover in response to a power
parameter measured for the source node falls that is determined to
be below a specified threshold.
41. The method of claim 32, further comprising making a handover
request determination in response to a load based handover
determination by the source node.
42. The method of claim 32, further comprising requesting
generation a flow composition based discontinuous reception (DRX)
pattern.
43. The method of claim 32, further comprising receiving the
neighbor list containing information that facilitates a handover
comprising a type identifier for a radio access technology, a
center frequency, and a system bandwidth.
44. The method of claim 32, further comprising receiving the
neighbor list containing information comprising a reference time
difference between the source node and the target node.
45. The method of claim 32, further comprising receiving the
neighbor list containing information comprising information
specific for a type of radio access technology.
46. At least one processor for inter-system handovers in a wireless
communication system, comprising: a first module for receiving a
neighbor list from a source node containing at least one parameter
for connecting to a target node proximal to a source node; a second
module for receiving a criterion for a user equipment (UE) to
determine when to pursue a handover to the target node; and a third
module for requesting handing over to the target node.
47. A computer program product for inter-system handovers in a
wireless communication system, comprising: a computer-readable
medium, comprising: a first set of codes for causing a computer to
receive a neighbor list from a source node containing at least one
parameter for connecting to a target node proximal to a source
node; a second set of codes for causing the computer to receive a
criterion for a user equipment (UE) to determine when to pursue a
handover to the target node; and a third set of codes for causing
the computer to request handing over to the target node.
48. An apparatus for inter-system handovers in a wireless
communication system, comprising: means for receiving a neighbor
list from a source node containing at least one parameter for
connecting to a target node proximal to a source node; means for
receiving a criterion for a user equipment (UE) to determine when
to pursue a handover to the target node; and means for requesting
handing over to the target node.
49. An apparatus for inter-system handovers in a wireless
communication system, comprising: a computer-readable medium for
receiving a data structure comprising a neighbor list from a source
node containing at least one parameter for connecting to a target
node proximal to a source node and containing a criterion for a
user equipment (UE) to determine when to pursue a handover to the
target node; a receiver for receiving the neighbor list and
criterion; and a transmitter for requesting handover to the target
node.
50. The apparatus of claim 49, further comprising the receiver
receiving the neighbor list and criterion while in idle mode, and
the transmitter requesting a location update request to the target
node that results in a location update acceptance by the target
node.
51. The apparatus of claim 49, further comprising the data
structure identifying a subset of neighboring nodes for the UE to
search.
52. The apparatus of claim 49, further comprising the receiver and
transmitter facilitating a handover by utilizing a single Rx chain
of a dual Rx chain.
53. The apparatus of claim 49, wherein the criterion for the UE to
determine when to pursue the handover to the target node further
comprises information prompting the UE to search for the target
node.
54. The apparatus of claim 53, wherein the information prompting
the search comprises at least one target node in the neighbor list
to prompt a search.
55. The apparatus of claim 54, wherein the information that prompts
the UE to search comprises a requirement that measured signal
strength from the source node has trended below a predetermined
threshold.
56. The apparatus of claim 49, wherein the criterion for requesting
the handover specifies a measured power parameter for the target
system trending more than a predetermined difference above a
measured power parameter for the source node.
57. The apparatus of claim 56, further comprising the receiver
measuring a power parameter from the source node falls that is
determined to be below a specified threshold as prerequisite for
the UE to report satisfaction of the criterion for the
handover.
58. The apparatus of claim 49, further comprising a processor
performing the handover request determination in response to
receiving load based handover determination.
59. The apparatus of claim 49, further comprising a processor
requesting generation of a flow composition based discontinuous
reception (DRX) pattern.
60. The apparatus of claim 49, wherein the neighbor list contains
information that facilitates the handover comprising a type
identifier for a radio access technology, a center frequency, and a
system bandwidth.
61. The apparatus of claim 49, wherein the neighbor list contains
information comprising a reference time difference between the
source node and the target node.
62. The apparatus of claim 49, wherein the neighbor list contains
information comprising information specific for a type of radio
access technology.
Description
CLAIM OF PRIORITY UNDER 35 U.S.C. .sctn.119
[0001] The present Application for Patent claims priority to
Provisional Application No. 60/891,025 entitled "A METHOD AND
APPARATUS FOR INTRA-SYSTEM HANDOFF" filed Feb. 21, 2007, and
assigned to the assignee hereof and hereby expressly incorporated
by reference herein.
FIELD OF INVENTION
[0002] The present description pertains to inter-system handovers
of user equipment and, more particularly, to reducing latency and
handover failure between different radio access technologies.
BACKGROUND
[0003] Wireless communication systems are widely deployed to
provide various types of communication content such as voice, data,
and so on. These systems may be multiple-access systems capable of
supporting communication with multiple users by sharing the
available system resources (e.g., bandwidth and transmit power).
Examples of such multiple-access systems include code division
multiple access (CDMA) systems, time division multiple access
(TDMA) systems, frequency division multiple access (FDMA) systems,
and orthogonal frequency division multiple access (OFDMA)
systems.
[0004] Generally, a wireless multiple-access communication system
can simultaneously support communication for multiple wireless
terminals. Each terminal communicates with one or more base
stations via transmissions on the forward and reverse links. The
forward link (or downlink) refers to the communication link from
the base stations to the terminals, and the reverse link (or
uplink) refers to the communication link from the terminals to the
base stations. This communication link may be established via a
single-in-single-out, multiple-in-single-out,
single-in-multiple-out (SIMO) or a multiple-in-multiple-out (MIMO)
system.
[0005] Due to data traffic, channel characteristics, or mobility of
user equipment (UE), a need frequently arises for a particular UE
to be handed over (i.e., hand-down, hand-up, etc.) between
different access nodes. This handover process is complicated by the
various states that a UE can be in for battery savings or channel
efficiency (e.g., idle, active, discontinuous
reception/transmission). This handover process is also complicated
by hand offs being made between different radio access technologies
(RAT). Other approaches, to the extent that inter-system RAT is
accommodated, are believed to be overly complicated (e.g., in
Wideband Code Division Multiple Access (WCDMA)).
SUMMARY
[0006] The following presents a simplified summary in order to
provide a basic understanding of some aspects of the disclosed
aspects. This summary is not an extensive overview and is intended
to neither identify key or critical elements nor delineate the
scope of such aspects. Its purpose is to present some concepts of
the described features in a simplified form as a prelude to the
more detailed description that is presented later.
[0007] In accordance with one or more aspects and corresponding
disclosure thereof, various aspects are described in connection
with an access point (source node) that directs an access terminal
(user equipment) to search for a target node, facilitated by
transmitting information for accessing in a neighbor list. A
handover request from the UE is predicated upon the UE determining
that reception from the target node relative to the source node
exceeds a criterion. Thereby, the source node can reduce the
latency and connection failures by providing the information to
access the target node and can selectively adjust to data traffic
loading. In particular, the information transmitted about neighbor
systems (target nodes) can advantageously accommodate a wide range
of radio access technologies.
[0008] In one aspect, a method for inter-system handovers in a
wireless communication system is provided wherein a source node
transmits a neighbor list containing at least one parameter for
connecting to a target node proximal to a source node. A criterion
is also transmitted for a user equipment (UE) to determine when to
pursue a handover to the target node. Then, the UE can be handed
over to the target node with reduced latency or connection
error.
[0009] In another aspect, at least one processor for inter-system
handovers in a wireless communication system has a first module for
transmitting a neighbor list from a source node containing at least
one parameter for connecting to a target node proximal to a source
node. A second module is for transmitting a criterion for a user
equipment (UE) to determine when to pursue a handover to the target
node. A third module is for handing over the UE to the target node
with reduced latency or connection error.
[0010] In an additional aspect, a computer program product for
inter-system handovers in a wireless communication system has a
computer-readable medium that contains sets of codes for causing a
computer to transmit a neighbor list from a source node containing
at least one parameter for connecting to a target node proximal to
a source node, to transmit a criterion for a user equipment (UE) to
determine when to pursue a handover to the target node, and to hand
over the UE to the target node with reduced latency or connection
error.
[0011] In yet another aspect, an apparatus for inter-system
handovers in a wireless communication system has a means for
transmitting a neighbor list from a source node containing at least
one parameter for connecting to a target node proximal to a source
node, another means for transmitting a criterion for a user
equipment (UE) to determine when to pursue a handover to the target
node, and yet an additional means for handing over the UE to the
target node with reduced latency or connection error.
[0012] In yet a further aspect, an apparatus for inter-system
handovers in a wireless communication system has a
computer-readable medium containing a data structure comprising a
neighbor list from a source node containing at least one parameter
for connecting to a target node proximal to a source node and
containing a criterion for a user equipment (UE) to determine when
to pursue a handover to the target node. A transmitter transmits
the neighbor list and criterion. A communication channel to the
target node facilitates handover of the UE to the target node with
reduced latency or connection error.
[0013] In yet an additional aspect, a method for inter-system
handovers in a wireless communication system includes receiving a
neighbor list from a source node containing at least one parameter
for connecting to a target node proximal to a source node. A
criterion for user equipment (UE) is received to determine when to
pursue a handover to the target node. Subsequently, handing over
the UE to the target node is requested with reduced latency or
connection error.
[0014] In yet another aspect, at least one processor for
inter-system handovers in a wireless communication system has a
first module for receiving a neighbor list from a source node
containing at least one parameter for connecting to a target node
proximal to a source node. A second module receives a criterion for
a user equipment (UE) to determine when to pursue a handover to the
target node. A third module for requesting handing over the UE to
the target node with reduced latency or connection error.
[0015] In an additional aspect, a computer program product for
inter-system handovers in a wireless communication system has a
computer-readable medium containing sets of codes for causing a
computer to receive a neighbor list from a source node containing
at least one parameter for connecting to a target node proximal to
a source node, to receive a criterion for a user equipment (UE) to
determine when to pursue a handover to the target node, and to
request handing over the UE to the target node with reduced latency
or connection error.
[0016] In yet a further aspect, an apparatus for inter-system
handovers in a wireless communication system has means for
receiving a neighbor list from a source node containing at least
one parameter for connecting to a target node proximal to a source
node, another means for receiving a criterion for a user equipment
(UE) to determine when to pursue a handover to the target node, and
an additional means for requesting handing over the UE to the
target node with reduced latency or connection error.
[0017] In an additional aspect, an apparatus for inter-system
handovers in a wireless communication system has a
computer-readable medium for receiving a data structure comprising
a neighbor list from a source node containing at least one
parameter for connecting to a target node proximal to a source node
and containing a criterion for a user equipment (UE) to determine
when to pursue a handover to the target node. A receiver receives
the neighbor list and criterion. In addition, a transmitter
requests handover to the target node with reduced latency or
connection error.
[0018] To the accomplishment of the foregoing and related ends, 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 aspects and are indicative of but a few of the various
ways in which the principles of the aspects may be employed. Other
advantages and novel features will become apparent from the
following detailed description when considered in conjunction with
the drawings and the disclosed aspects are intended to include all
such aspects and their equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The features, nature, and advantages of the present
disclosure will become more apparent from the detailed description
set forth below when taken in conjunction with the drawings in
which like reference characters identify correspondingly throughout
and wherein:
[0020] FIG. 1 illustrates a block diagram of a wireless
communication system of a user equipment (UE) moving from a
coverage area of source radio access network (RAN) to a neighboring
RAN warranting an inter-system handover;
[0021] FIG. 2 illustrates a block diagram of an illustrative source
RAN of FIG. 1;
[0022] FIG. 3 illustrates a flow diagram for a methodology for
inter-system handovers performed by the wireless communication
system of FIG. 1;
[0023] FIG. 4 illustrates a timing diagram of the wireless
communication system of FIG. 1 with the UE in an active state being
set up by a source base access node (nodeB) for inter-system
handover;
[0024] FIG. 5 illustrates a timing diagram of the wireless
communication system of FIG. 1 with the UE in an idle state being
set up by the nodeB for inter-system handover;
[0025] FIG. 6 illustrates a flow diagram of a methodology set up by
the NodeB and performed by the UE of FIG. 1 for determining when or
if to start other-system search in preparation for inter-system
handover;
[0026] FIG. 7 illustrates a flow diagram of a methodology set up by
the NodeB and performed by the UE of FIG. 1 for determining when or
if the UE requests handover;
[0027] FIG. 8 illustrates a block diagram of an access node (NodeB)
having modules configured to cause a computer to perform the
functions for inter-system handover;
[0028] FIG. 9 illustrates a block diagram of an access terminal
(UE) having modules configured to cause a computer to perform the
functions for inter-system handover;
[0029] FIG. 10 illustrates a block diagram of a communication
system enhanced to support inter-system handovers;
[0030] FIG. 11 illustrates a diagram of a multiple access wireless
communication system according to one aspect for supporting
flexible DRX; and
[0031] FIG. 12 illustrates a schematic block diagram of a
communication system for supporting flexible DRX.
DETAILED DESCRIPTION
[0032] An inter-system handover system for a wireless communication
system supports hand-down and hand-up of a user equipment (UE) to
different radio access technologies (e.g., 3GPP LTE (Third
Generation Partnership Project Long Term Evolution, GSM (Global
System for Mobile Communications), WCDMA (Wideband Code Division
Multiple Access)/High Speed Packet Access variants (e.g.,
HSxPA/HSPA+), 1.times. Evolution-Data Only (1.times./DO), Ultra
Mobile Broadband (UMB), Worldwide Interoperability for Microwave
Access (WiMAX), etc.), including synchronous and asynchronous
systems. Latency and handover connection failures are reduced by an
access node (nodeB) broadcasting information about neighboring
systems (targets) when the UE reception (RX) capability is both
inside or outside the reception range of the target. A single RX
chain is sufficient, although transitioning between a wireless wide
area network (WWAN) to a wireless local area network (WLAN) may
advantageously benefit from simultaneous operation on two Rx
chains. Optimized list of neighboring RAT systems (targets) are
broadcast from the network, including measurement parameters and
reporting instructions. Thereby, UE-driven reporting minimizes
latencies. UE reports other-system searches to network only if
needed for a handover. In addition, handover requests can be
bundled with other-system measurement information, if necessary,
for additional efficiencies.
[0033] 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 the various aspects may be practiced without
these specific details. In other instances, well-known structures
and devices are shown in block diagram form in order to facilitate
describing these aspects.
[0034] As used in this application, the terms "component",
"module", "system", and the like are intended to refer to a
computer-related entity, either hardware, a combination of hardware
and software, software, or software in execution. For example, a
component may be, but is not limited to being, a process running on
a processor, a processor, an object, an executable, a thread of
execution, a program, or a computer. By way of illustration, both
an application running on a server and the server can be a
component. One or more components may reside within a process or
thread of execution and a component may be localized on one
computer or distributed between two or more computers.
[0035] The word "exemplary" is used herein to mean serving as an
example, instance, or illustration. Any aspect or design described
herein as "exemplary" is not necessarily to be construed as
preferred or advantageous over other aspects or designs.
[0036] Furthermore, the one or more versions may be implemented as
a method, apparatus, or article of manufacture using standard
programming or engineering techniques to produce software,
firmware, hardware, or any combination thereof to control a
computer to implement the disclosed aspects. The term "article of
manufacture" (or alternatively, "computer program product") as used
herein is intended to encompass a computer program accessible from
any computer-readable device, carrier, or media. For example,
computer readable media can include but are not limited to magnetic
storage devices (e.g., hard disk, floppy disk, magnetic strips . .
. ), optical disks (e.g., compact disk (CD), digital versatile disk
(DVD) . . . ), smart cards, and flash memory devices (e.g., card,
stick). Additionally it should be appreciated that a carrier wave
can be employed to carry computer-readable electronic data such as
those used in transmitting and receiving electronic mail or in
accessing a network such as the Internet or a local area network
(LAN). Of course, those skilled in the art will recognize many
modifications may be made to this configuration without departing
from the scope of the disclosed aspects.
[0037] Various aspects will be presented in terms of systems that
may include a number of components, modules, and the like. It is to
be understood and appreciated that the various systems may include
additional components, modules, etc., or may not include all of the
components, modules, etc., discussed in connection with the
figures. A combination of these approaches may also be used. The
various aspects disclosed herein can be performed on electrical
devices including devices that utilize touch screen display
technologies or mouse-and-keyboard type interfaces. Examples of
such devices include computers (desktop and mobile), smart phones,
personal digital assistants (PDAs), and other electronic devices
both wired and wireless.
[0038] Referring initially to FIG. 1, in one aspect, a wireless
communication system 10 enhances data traffic loading or reduces
latency/connection errors during handover of user equipment (UE) 12
between a source radio access network (RAN) 14 and a neighboring
RAN 16. In particular, the source RAN 14 either requests over a
network connection or receives broadcast data, depicted at 18,
parameters for the neighboring RAN 16. Examples of such parameters
include information for handover between different radio access
technologies (inter-RAT) such as system type, center frequency,
etc. The source RAN 14 sends a Neighbor List (NL) 22 to prompt, or
to at least provision, the UE 12 for searching for another system
for connection. The source RAN 14 also sends at least one criterion
to enable a hand-off algorithm 24 for the UE 12 to execute. This
algorithm 24 allows the source RAN 14 to dictate conditions under
which the UE 12 should seek a handover. This algorithm 24 can
reflect data traffic load on the source RAN 14 to avoid congestion.
This algorithm 24 can distribute processing loads to the UE 12 as
well reducing measurement-reporting requirements that would
otherwise be required for the source RAN 14 to determine when a
handover is warranted.
[0039] Referring to FIG. 2, in another aspect, a communication
system 110 includes an evolved Universal Mobile Telecommunications
System (UMTS) Terrestrial Radio Access Network (E-UTRAN) 112 that
incorporates an inter-system handover system 114 between at last
one radio access network (RAN), depicted as an evolved base node
(eNode B) 116 and a user equipment (UE) device 118. Another
in-range eNode B 120 for multiple input multiple output (NIMO)
communications is depicted as being available for a handover. Yet a
third eNode B 122 is depicted as being out of range of UE device
118.
[0040] The eNode Bs 116, 120, 122 provide an UMTS Terrestrial Radio
Access (E-UTRA) user plane and control plane (RRC) protocol
terminations towards the UE 118. The user plane can comprise of
3GPP (3rd Generation Partnership Project) Packet Data Convergence
Protocol (PDCP), radio link control (RLC), medium access control
(MAC) and physical layer control (PHY). The eNode Bs 116, 120, 122
are interconnected with each other by means of X2 interface ("X2").
The eNode Bs 116, 120, 122 are also connected by means of an S1
interface ("S1") to an EPC (Evolved Packet Core), more specifically
to mobility management entities/serving gateways (MME/S-GW) 126,
128 connected to a data packet network 130. The S1 interface
supports a many-to-many relation between MMEs/S-GW 126, 128 and
eNode Bs 116, 120, 122.
[0041] The eNode Bs 116, 120, 122 hosts the following functions:
radio resource management; radio bearer control; radio admission
control; connection mobility control; dynamic allocation of
resources to UEs in both uplink and downlink (scheduling); IP
header compression and encryption of user data stream; selection of
an MME at UE attachment; routing of user plane data towards serving
gateway; scheduling and transmission of paging messages (originated
from the MME); scheduling and transmission of broadcast
information; and measurement reporting configuration for mobility
and scheduling.
[0042] The MME hosts the following functions: distribution of
paging messages to the eNodes Bs 116, 120, 122; security control;
idle state mobility control; System Architecture Evolution (SAE)
bearer control; ciphering and integrity protection of Non-Access
Stratum (NAS) signaling. The Serving Gateway hosts the following
functions termination of U-plane packets for paging reasons and
switching of U-plane for support of UE mobility.
[0043] In FIG. 3, a methodology 200 for inter-system handovers
begins with a source base node (NodeB) maintaining parameters
necessary for handover to a neighboring system (block 202). The
source NodeB transmits neighbor list (NL) to a UE (block 204). This
NL can specify a type of RAT for each target (e.g., GSM, WCDMA,
HSxPA, LTE, 1.times./DO, UMB, WiMAX, etc.), the center frequency,
system bandwidth, reference time difference between source and each
target, or other system specific information. For instance, the
latter can include color code and pseudo noise (PN) offset, cell
ID. As another example, the latter can also include center
frequency plus scrambling code for WCDMA/HSxPA. This transmission
can be unicast in some instances; however, in the exemplary
methodology this NL may be broadcast to a population of UEs. A
handover algorithm is thus transmitted from the source NodeB to the
UE in block 206. In some instances, broadcast of the NL alone is
sufficient to prompt UEs to begin searching for the target NodeBs
contained in the NL. In other instances, the algorithm initially
dictates conditions/criteria necessary as a prerequisite for
beginning to search, such as energy per symbol to interference
density ratio (Es/Io) measured from the source NodeB. Alternatively
or in addition, the algorithm dictates conditions under which the
UE requests a handover.
[0044] The UEs typically have sufficient spare interlaces to
perform required measurements. The source NodeB can maintain a
desired number of interlaces (DRX patterns) for other system
measurements for each system type (block 208). Once a determination
is made that the UE should initiate search for another system in
block 210 (e.g., responding to receipt of NL, responding to both NL
and an algorithm/search criterion, etc.), then the handover
algorithm is executed to determine whether handover is warranted
(block 212). Then the UE requests the handover (block 214), which
the Source NodeB considers for granting or denying (block 216). For
instance, the handover algorithm can alert the source NodeB of the
option to handover in order to balance loading. If the measurements
indicate that a handover must be made to maintain connection, then
this may result in an increased emphasis on granting.
[0045] In FIG. 4, a timing diagram for a methodology 300 for
communications between an active UE 302 with a Source NodeB 304 is
depicted that culminate in a handover to a Target NodeB 306. In
block 308, the Source NodeB 304 broadcasts a system information
block (SIB) that is applicable to UE 302 both in idle and in active
states. The measurement and reporting parameters in the SIB can be
dynamically changed by the network, such as being periodically
transmitted on the broadcast control channel (BCCH) to reflect
availability of target nodes or local loading conditions. In block
310, the UE 302 extracts the NL and search algorithm from the SIB
in order to determine when to start searching for another system.
Receipt of the NL may suffice to initiate the search. For example,
the Source NodeB 304 may refrain from broadcasting an NL until
loading conditions are such that it is desired to know which UEs
302 could connect with target node. Alternatively, the start
algorithm could require a further determination that the received
signal strength from the source NodeB 304 has dropped below a
certain threshold.
[0046] In block 312, in some instances the UE 302 can request
discontinuous reception (DRX) in order to accommodate searching for
the target system(s); however is should be appreciated with the
benefit of the present disclosure that searching for the other
system may not require such a request. In response in block 314,
the source NodeB 304 can execute an algorithm for (a) load based
handover or (b) flow composition based DRX pattern. Then in block
316, the corresponding message is sent from the Source NodeB 304 to
the UE 302. If the latter, then a target system search command is
sent that includes target system information and response
parameters (TVM, position location, UE international measurements,
etc.). If the latter, a DRX pattern is granted. In block 318, the
UE 302 begins search for a target system/cell for handover.
[0047] In block 320, for instances in which the UE 302 is in a
continuous packet connectivity mode, the UE 302 can access the
random access channel (RACH), resulting in a connection setup
procedure in block 322 between the UE 302 and the source NodeB
304.
[0048] In block 324, the UE 302 responds with a handover request or
a target search response. Measurements can be bundled up with the
response including the TVM for the queue size of a target nodeB 306
or a received power measurement (e.g., Es/Io, RSSI, etc.).
[0049] In block 326, the source NodeB 304 makes a determination
whether to grant or deny the handover. If granted, in block 328 the
source NodeB 304 can communicate with the target nodeB 306 using
the target information from the UE 302. The target nodeB 306 grants
the handover in block 330, which can include target system
information for use by the UE 302. The source NodeB 304 responds
for relaying the handover grant to the UE 302 in block 332, which
can include target system information if applicable. Thereby
latency and connection failures are reduced by facilitating the
handover.
[0050] In FIG. 5, a methodology for 400 is depicted for a UE 402
that is in idle state with a source NodeB 404 to perform a handover
to a target nodeB 406. In block 408, the source NodeB 404 transmits
measurement and reporting parameters in a measurement SIB, whose
broadcast includes information about neighboring NodeB (i.e.,
target NodeB 406). In block 410, the UE 402 responds to the NL and
the search algorithm received by starting to search for the target
nodeB 406. This search can be predicated upon the received signal
strength (e.g., Es/Io) from the source nodeB 404 dropping below a
predetermined threshold. In block 412, a further aspect of the
NL/search algorithm is performed to determine when sufficient
connectivity has been sensed to warrant a location update request.
When this is determined, then in block 414, the UE 402 makes a
location update request to the target nodeB 406, which in turn
responds with a location update accepted in block 416.
[0051] In FIG. 6, a methodology 500 for determining when or if the
UE is to start another-system search as mentioned above begins with
receiving the algorithm from the source NodeB in block 502. In
block 504, the list of neighboring systems is received, which in
the illustrative depiction can be a type of RAT system (e.g., GSM,
WCDMA, HSxPA, LTE, 1.times./DO, UMB, WiMAX). It can include center
frequency, system bandwidth, reference time difference between
source and target, or system specific information (e.g.,
1.times./DO color code and PN offset; WCDMA/HSxPA cell ID, center
frequency and scrambling code, etc.). In block 506, the source
NodeB may have designated a subset of the NL for searching and not
the entire list. In block 508, a determination is made as to
whether another system is contained in the NL for targeting. If
not, then the methodology 500 exits at block 510 until an
applicable NL is received.
[0052] If a target system was found in block 508, then, if
required, a one-tap Infinite Impulse Response (IIR) filter time
constant for source NodeB Es/Io is performed in block 512. A
determination is then made in block 514 whether the filtered
measurement of Es/Io for the source NodeB has fallen below a
specified threshold (".tau..sub.1"). If so in block 514 or if
receipt of NL was sufficient for searching in block 508, then a
search is performed using the second RX chain if available in block
516. However, in many instances, due to cosmetic and cost
considerations, a secondary Rx chain sensitivity may be lower than
a primary Rx chain. The methodology thus accommodates this by
assuming that a single radio VCC for inter-RAT handover (i.e.,
independently tunable RX chains or simultaneous dual system
reception/processing is not presumed). It should be appreciated
that having dual RX chains does enhance handover, for example, by
being able to receive contiguous ten frames of a GSM system whose
capture allows quicker GSM system acquisition. In block 518, it may
be necessary for the UE to request DRX in order to facilitate
searching.
[0053] In FIG. 7, a methodology 600 for determining when or if a UE
requests a handover is performed after performing the search such
as depicted above in FIG. 6. This list of one or more target
systems can be limited to those specified in a subset of the NL by
the source NodeB, depicted in block 602. For clarity, measurement
of one target nodeB is depicted, although it should be appreciated
with the benefit of the present disclosure that multiple target
nodeBs may be monitored for possible handover. In block 604, a
measure representative of target nodeB received power is performed,
such as Es/Io. This measure is low pass filtered in block 606,
which in the illustrative depiction utilizes a one-tap IIR filter
"y(n)=(1/T.sub.c)x(n)+(1-1/T.sub.c)y(n-1)". In block 608, a
calculation is made as to whether this signal over time appears to
be strong enough (e.g., minimum credits). In the illustrative
depiction, a credit is incremented for each interval in which the
target Es/Io power level (dB) exceeds the source Es/Io by some
preset difference and otherwise decrements the credit. In block
610, a determination is made as to whether the accumulated credits
exceed a minimum credits threshold (".tau..sub.MC"). If so, a
further determination is made as to whether this result was arrived
at based upon a UE-initiated search in block 612, and if so, a
further determination is made if the target energy per chip to
interference density ratio (Ec/Io) exceeds a minimum report
threshold specified by the source NodeB in block 614. If so, or if
not UE initiated search in block 612, then the UE requests a
handover in block 616.
[0054] In FIG. 8, in another aspect, an access node 700 includes
modules that provide a means to cause a computer to participate in
or to perform the methodologies of FIGS. 3-7. A module 702 is
provided for sending neighbor list (NL) containing handover
critical information. A module 704 is provided for specifying
algorithm for UE starting other-system search. A module 706 is
provided for load-based determination for granting handover. A
module 708 is provided for specifying flow composition based DRX
pattern. A module 710 is provided for controlling random access
channel (RACH) call setup. A module 712 is provided for
coordinating handover with a target system.
[0055] In FIG. 9, in another aspect, an access terminal 800
includes modules that provide a means to cause a computer to
participate in or to perform the methodologies of FIGS. 3-8. A
module 802 is provided for receiving neighbor list (NL) containing
handover critical information. A module 804 is provided for
implementing an algorithm for UE starting other-system search. A
module 806 is provided for requesting load-based determination for
granting handover. A module 808 is provided for requesting flow
composition based DRX pattern. A module 810 is provided for
requesting random access channel (RACH) call setup. A module 812 is
provided for prompting coordination of a handover with a target
system.
[0056] In FIG. 10, in another aspect, a communication system 900
that can encompass the communication system 10 of FIG. 1 includes
support for interfacing an evolved packet core 902 via an interface
S4 with a legacy General Packet Radio Service (GPRS) core 904,
whose Serving GPRS Support Node (SGSN) 906 is interfaced in turn by
a Gb interface to a Global System for Mobile Communications
(GSM)/Edge Radio Access Network (GERAN) 908 and via an 1u interface
to a UTRAN 910. The S4 provides the user plane with related control
and mobility support between GPRS Core 904 and a 3GPP Anchor 912 of
an Inter Access Stratum Anchor (IASA) 914 and is based on a Gn
reference point as defined between SGSN 906 and Gateway GPRS
Serving/Support Node (GGSN) (not shown). The IASA 914 also includes
a system architecture evolved (SAE) anchor 916 interfaced to the
3GPP anchor 912 by an S5b interface that provides the user plane
with related control and mobility support. The 3GPP anchor 912
communicates with an MME UPE 918 via interface S5a. Mobility
Management Entity (MME) pertains to distribution of paging messages
to the eNBs and User Plane Entity (UPE) pertains to IP header
compression and encryption of user data streams, termination of
U-plane packets for paging reasons, and switching of U-plane for
support of UE mobility. The MME UPE 918 communicates via interface
S1 to an evolved RAN 920 for wirelessly communicating with UE
devices 922.
[0057] An S2b interface provides the user plane with related
control and mobility support between the SAE Anchor 916 and an
evolved Packet Data Gateway (ePDG) 924 of a wireless local access
network (WLAN) 3GPP IP Access component 926 that also includes a
WLAN Access network (NW) 928. An SGi interface is the reference
point between the Inter AS Anchor 916 and a packet data network
930. Packet data network 930 may be an operator external public or
private packet data network or an intra operator packet data
network, e.g., for provision of IP Multimedia Subsystem (IMS)
services. This SGi reference point corresponds to Gi and Wi
functionalities and supports any 3GPP and non-3GPP access systems.
An Rx+ interface provides communication between the packet data
network 930 and a policy and charging rules function (PCRF) 932,
which in turn communicates via an S7 interface to the evolved
packet core 902. The S7 interface provides transfer of (QoS) policy
and charging rules from PCRF 932 to Policy and Charging Enforcement
Point (PCEP) (not shown). An S6 interface (i.e., AAA interface)
enables transfer of subscription and authentication data for
authenticating/authorizing user access by interfacing the evolved
packet core 902 to a home subscriber service (HSS) 934. An S2a
interface provides the user plane with related control and mobility
support between a trusted non-3GPP IP access 936 and the SAE Anchor
916.
[0058] It should be appreciated that wireless communication systems
are widely deployed to provide various types of communication
content such as voice, data, and so on. These systems may be
multiple-access systems capable of supporting communication with
multiple users by sharing the available system resources (e.g.,
bandwidth and transmit power). Examples of such multiple-access
systems include code division multiple access (CDMA) systems, time
division multiple access (TDMA) systems, frequency division
multiple access (FDMA) systems, 3GPP LTE systems, and orthogonal
frequency division multiple access (OFDMA) systems.
[0059] Generally, a wireless multiple-access communication system
can simultaneously support communication for multiple wireless
terminals. Each terminal communicates with one or more base
stations via transmissions on the forward and reverse links. The
forward link (or downlink) refers to the communication link from
the base stations to the terminals, and the reverse link (or
uplink) refers to the communication link from the terminals to the
base stations. This communication link may be established via a
single-in-single-out, multiple-in-single-out,
single-in-multiple-out (SIMO) or a multiple-in-multiple-out (MIMO)
system.
[0060] A MIMO system employs multiple (N.sub.T) transmit antennas
and multiple (N.sub.R) receive antennas for data transmission. A
MIMO channel formed by the N.sub.T transmit and N.sub.R receive
antennas may be decomposed into N.sub.S independent channels, which
are also referred to as spatial channels, where N.sub.S.ltoreq.min
{N.sub.T, N.sub.R)}. Each of the N.sub.S independent channels
corresponds to a dimension. The MIMO system can provide improved
performance (e.g., higher throughput or greater reliability) if the
additional dimensionalities created by the multiple transmit and
receive antennas are utilized.
[0061] A MIMO system supports a time division duplex (TDD) and
frequency division duplex (FDD) systems. In a TDD system, the
forward and reverse link transmissions are on the same frequency
region so that the reciprocity principle allows the estimation of
the forward link channel from the reverse link channel. This
enables the access point to extract transmit beam forming gain on
the forward link when multiple antennas are available at the access
point.
[0062] Referring to FIG. 11, a multiple access wireless
communication system according to one aspect is illustrated. An
access point 1000 (AP) includes multiple antenna groups, one
including 1004 and 1006, another including 1008 and 1010, and an
additional including 1012 and 1014. In FIG. 11, only two antennas
are shown for each antenna group, however, more or fewer antennas
may be utilized for each antenna group. Access terminal 1016 (AT)
is in communication with antennas 1012 and 1014, where antennas
1012 and 1014 transmit information to access terminal 1016 over
forward link 1020 and receive information from access terminal 1016
over reverse link 1018. Access terminal 1022 is in communication
with antennas 1006 and 1008, where antennas 1006 and 1008 transmit
information to access terminal 1022 over forward link 1026 and
receive information from access terminal 1022 over reverse link
1024. In a FDD system, communication links 1018, 1020, 1024 and
1026 may use different frequency for communication. For example,
forward link 1020 may use a different frequency then that used by
reverse link 1018.
[0063] Each group of antennas or the area in which they are
designed to communicate is often referred to as a sector of the
access point. In this aspect, antenna groups each are designed to
communicate to access terminals in a sector, of the areas covered
by access point 1000.
[0064] In communication over forward links 1020 and 1026, the
transmitting antennas of access point 1000 utilize beam forming in
order to improve the signal-to-noise ratio of forward links for the
different access terminals 1016 and 1024. In addition, an access
point using beam forming to transmit to access terminals scattered
randomly through its coverage causes less interference to access
terminals in neighboring cells than an access point transmitting
through a single antenna to all its access terminals.
[0065] An access point may be a fixed station used for
communicating with the terminals and may also be referred to as an
access point, a Node B, or some other terminology. An access
terminal may also be called an access terminal, user equipment
(UE), a wireless communication device, terminal, access terminal or
some other terminology.
[0066] FIG. 12 is a block diagram of an aspect of a transmitter
system 1110 (also known as the access point) and a receiver system
1150 (also known as access terminal) in a MIMO system 1100. At the
transmitter system 1110, traffic data for a number of data streams
is provided from a data source 1112 to a transmit (TX) data
processor 1114.
[0067] In an aspect, each data stream is transmitted over a
respective transmit antenna. TX data processor 1114 formats, codes,
and interleaves the traffic data for each data stream based on a
particular coding scheme selected for that data stream to provide
coded data.
[0068] The coded data for each data stream may be multiplexed with
pilot data using OFDM techniques. The pilot data is typically a
known data pattern that is processed in a known manner and may be
used at the receiver system to estimate the channel response. The
multiplexed pilot and coded data for each data stream is then
modulated (i.e., symbol mapped) based on a particular modulation
scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for that data
stream to provide modulation symbols. The data rate, coding, and
modulation for each data stream may be determined by instructions
performed by processor 1130.
[0069] The modulation symbols for all data streams are then
provided to a TX MIMO processor 1120, which may further process the
modulation symbols (e.g., for OFDM). TX MIMO processor 1120 then
provides N.sub.T modulation symbol streams to N.sub.T transmitters
(TMTR) 1122a through 1122t. In certain implementations, TX MIMO
processor 1120 applies beam-forming weights to the symbols of the
data streams and to the antenna from which the symbol is being
transmitted.
[0070] Each transmitter 1122 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. N.sub.T modulated signals from transmitters
1122a through 1122t are then transmitted from N.sub.T antennas
1124a through 1124t, respectively.
[0071] At receiver system 1150, the transmitted modulated signals
are received by N.sub.R antennas 1152a through 1152r and the
received signal from each antenna 1152 is provided to a respective
receiver (RCVR) 1154a through 1154r. Each receiver 1154 conditions
(e.g., filters, amplifies, and downconverts) a respective received
signal, digitizes the conditioned signal to provide samples, and
further processes the samples to provide a corresponding "received"
symbol stream.
[0072] An RX data processor 1160 then receives and processes the
N.sub.R received symbol streams from N.sub.R receivers 1154 based
on a particular receiver processing technique to provide N.sub.T
"detected" symbol streams. The RX data processor 1160 then
demodulates, deinterleaves, and decodes each detected symbol stream
to recover the traffic data for the data stream. The processing by
RX data processor 1160 is complementary to that performed by TX
MIMO processor 1120 and TX data processor 1114 at transmitter
system 1110.
[0073] A processor 1170 periodically determines which pre-coding
matrix to use (discussed below). Processor 1170 formulates a
reverse link message comprising a matrix index portion and a rank
value portion.
[0074] The reverse link message may comprise various types of
information regarding the communication link or the received data
stream. The reverse link message is then processed by a TX data
processor 1138, which also receives traffic data for a number of
data streams from a data source 1136, modulated by a modulator
1180, conditioned by transmitters 1154a through 1154r, and
transmitted back to transmitter system 1110.
[0075] At transmitter system 1110, the modulated signals from
receiver system 1150 are received by antennas 1124, conditioned by
receivers 1122, demodulated by a demodulator 1140, and processed by
a RX data processor 1142 to extract the reserve link message
transmitted by the receiver system 1150. Processor 1130 then
determines which pre-coding matrix to use for determining the beam
forming weights then processes the extracted message.
[0076] In an aspect, logical channels are classified into Control
Channels and Traffic Channels. Logical Control Channels comprises
Broadcast Control Channel (BCCH), which is DL channel for
broadcasting system control information. Paging Control Channel
(PCCH), which is DL channel that transfers paging information.
Multicast Control Channel (MCCH) which is Point-to-multipoint DL
channel used for transmitting Multimedia Broadcast and Multicast
Service (MBMS) scheduling and control information for one or
several MTCHs. Generally, after establishing RRC connection this
channel is only used by UEs that receive MBMS (Note: old
MCCH+MSCH). Dedicated Control Channel (DCCH) is Point-to-point
bi-directional channel that transmits dedicated control information
and used by UEs having an RRC connection. In an aspect, Logical
Traffic Channels comprises a Dedicated Traffic Channel (DTCH),
which is Point-to-point bi-directional channel, dedicated to one
UE, for the transfer of user information. In addition, a Multicast
Traffic Channel (MTCH) for Point-to-multipoint DL channel for
transmitting traffic data.
[0077] In an aspect, Transport Channels are classified into DL and
UL. DL Transport Channels comprises a Broadcast Channel (BCH),
Downlink Shared Data Channel (DL-SDCH) and a Paging Channel (PCH),
the PCH for support of UE power saving (DRX cycle is indicated by
the network to the UE), broadcasted over entire cell and mapped to
PHY resources which can be used for other control/traffic channels.
The UL Transport Channels comprises a Random Access Channel (RACH),
a Request Channel (REQCH), an Uplink Shared Data Channel (UL-SDCH)
and a plurality of PHY channels. The PHY channels comprise a set of
DL channels and UL channels.
[0078] The DL PHY channels comprise: Common Pilot Channel (CPICH);
Synchronization Channel (SCH); Common Control Channel (CCCH);
Shared DL Control Channel (SDCCH); Multicast Control Channel
(MCCH); Shared UL Assignment Channel (SUACH); Acknowledgement
Channel (ACKCH); DL Physical Shared Data Channel (DL-PSDCH); UL
Power Control Channel (UPCCH); Paging Indicator Channel (PICH);
Load Indicator Channel (LICH); The UL PHY Channels comprises:
Physical Random Access Channel (PRACH); Channel Quality Indicator
Channel (CQICH); Acknowledgement Channel (ACKCH); Antenna Subset
Indicator Channel (ASICH); Shared Request Channel (SREQCH); UL
Physical Shared Data Channel (UL-PSDCH); Broadband Pilot Channel
(BPICH).
[0079] What has been described above includes examples of the
various aspects. It is, of course, not possible to describe every
conceivable combination of components or methodologies for purposes
of describing the various aspects, but one of ordinary skill in the
art may recognize that many further combinations and permutations
are possible. Accordingly, the subject specification intended to
embrace all such alterations, modifications, and variations that
fall within the spirit and scope of the appended claims.
[0080] In particular and in regard to the various functions
performed by the above described components, devices, circuits,
systems and the like, the terms (including a reference to a
"means") used to describe such components are intended to
correspond, unless otherwise indicated, to any component which
performs the specified function of the described component (e.g., a
functional equivalent), even though not structurally equivalent to
the disclosed structure, which performs the function in the herein
illustrated exemplary aspects. In this regard, it will also be
recognized that the various aspects include a system as well as a
computer-readable medium having computer-executable instructions
for performing the acts or events of the various methods.
[0081] In addition, while a particular feature may have been
disclosed with respect to only one of several implementations, such
feature may be combined with one or more other features of the
other implementations as may be desired and advantageous for any
given or particular application. To the extent that the terms
"includes" and "including" and variants thereof are used in either
the detailed description or the claims, these terms are intended to
be inclusive in a manner similar to the term "comprising."
Furthermore, the term "or" as used in either the detailed
description of the claims is meant to be a "non-exclusive or".
[0082] Furthermore, as will be appreciated, various portions of the
disclosed systems and methods may include or consist of artificial
intelligence, machine learning, or knowledge or rule based
components, sub-components, processes, means, methodologies, or
mechanisms (e.g., support vector machines, neural networks, expert
systems, Bayesian belief networks, fuzzy logic, data fusion
engines, classifiers . . . ). Such components, inter alia, can
automate certain mechanisms or processes performed thereby to make
portions of the systems and methods more adaptive as well as
efficient and intelligent. By way of example and not limitation,
the evolved RAN (e.g., access point, eNode B) can infer or predict
data traffic conditions and opportunities for facilitating handover
to another type of RAT with reduced latency and connection errors
based on previous interactions with the same or like machines under
similar conditions.
[0083] In view of the exemplary systems described supra,
methodologies that may be implemented in accordance with the
disclosed subject matter have been described with reference to
several flow diagrams. While for purposes of simplicity of
explanation, the methodologies are shown and described as a series
of blocks, it is to be understood and appreciated that the claimed
subject matter is not limited by the order of the blocks, as some
blocks may occur in different orders or concurrently with other
blocks from what is depicted and described herein. Moreover, not
all illustrated blocks may be required to implement the
methodologies described herein. Additionally, it should be further
appreciated that the methodologies disclosed herein are capable of
being stored on an article of manufacture to facilitate
transporting and transferring such methodologies to computers. The
term article of manufacture, as used herein, is intended to
encompass a computer program accessible from any computer-readable
device, carrier, or media.
[0084] It should be appreciated that any patent, publication, or
other disclosure material, in whole or in part, that is said to be
incorporated by reference herein is incorporated herein only to the
extent that the incorporated material does not conflict with
existing definitions, statements, or other disclosure material set
forth in this disclosure. As such, and to the extent necessary, the
disclosure as explicitly set forth herein supersedes any
conflicting material incorporated herein by reference. Any
material, or portion thereof, that is said to be incorporated by
reference herein, but which conflicts with existing definitions,
statements, or other disclosure material set forth herein, will
only be incorporated to the extent that no conflict arises between
that incorporated material and the existing disclosure
material.
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