U.S. patent application number 14/156439 was filed with the patent office on 2015-01-22 for dual sim dual active subscriber identification module with a single transmit chain and dual or single receive chain.
This patent application is currently assigned to QUALCOMM Incorporated. The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Rashid Ahmed Akbar Attar, Jun Hu, Huang Lou, Joseph B. Soriaga, Jing Sun.
Application Number | 20150023230 14/156439 |
Document ID | / |
Family ID | 52247803 |
Filed Date | 2015-01-22 |
United States Patent
Application |
20150023230 |
Kind Code |
A1 |
Hu; Jun ; et al. |
January 22, 2015 |
DUAL SIM DUAL ACTIVE SUBSCRIBER IDENTIFICATION MODULE WITH A SINGLE
TRANSMIT CHAIN AND DUAL OR SINGLE RECEIVE CHAIN
Abstract
A method, an apparatus, and a computer program product are
provided. The apparatus may be configured to establish a first call
for a first subscription, and accept a second call for a second
subscription while maintaining the first call. A single RF transmit
chain may be scheduled for uplink transmissions associated with the
first call and uplink transmissions associated with the second
call. A timesharing schedule for the transmit chain may determine
timing for the uplink transmissions associated with the first call
is transmitted and when the uplink transmissions associated with
the second call is transmitted on the transmit chain. Downlink
transmissions associated with the first and second calls may be
received using different receive chain. Downlink transmissions
associated with the first and second calls may be received using
the same receive chain.
Inventors: |
Hu; Jun; (San Diego, CA)
; Attar; Rashid Ahmed Akbar; (San Diego, CA) ;
Soriaga; Joseph B.; (San Diego, CA) ; Sun; Jing;
(San Diego, CA) ; Lou; Huang; (San Diego,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Assignee: |
QUALCOMM Incorporated
San Diego
CA
|
Family ID: |
52247803 |
Appl. No.: |
14/156439 |
Filed: |
January 15, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14134898 |
Dec 19, 2013 |
|
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14156439 |
|
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61856440 |
Jul 19, 2013 |
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Current U.S.
Class: |
370/280 ;
370/329; 370/335; 370/336 |
Current CPC
Class: |
H04W 76/28 20180201;
H04W 88/06 20130101; H04W 8/18 20130101; H04L 5/14 20130101; H04W
76/16 20180201; H04W 72/1215 20130101; H04W 76/15 20180201; H04W
76/25 20180201; H04W 4/16 20130101; H04W 72/1205 20130101 |
Class at
Publication: |
370/280 ;
370/329; 370/336; 370/335 |
International
Class: |
H04W 72/12 20060101
H04W072/12; H04L 5/14 20060101 H04L005/14 |
Claims
1. A method of managing multiple connections for an access
terminal, comprising: establishing a first call for a first
subscription associated with the access terminal; accepting a
second call for a second subscription associated with the access
terminal while maintaining the first call in an active state; and
scheduling a single radio frequency (RF) transmit chain provided in
the access terminal for uplink transmissions associated with the
first call and uplink transmissions associated with the second call
when the access terminal is operating in a first mode.
2. The method of claim 1, further comprising: scheduling the single
RF transmit chain provided in the access terminal to restrict
uplink transmissions to a single call when the access terminal is
operating in a second mode; and falling back to the second mode
from the first mode when one or more channel conditions are
determined, the channel conditions comprising high network loading,
high transmit power or adverse RF coexistence conditions.
3. The method of claim 2, wherein the first mode is a dual SIM dual
active (DSDA) mode and the second mode is a dual SIM dual stand-by
(DSDS) mode.
4. The method of claim 2, further comprising: selecting either the
first call or the second call to be dropped when the access
terminal falls back to the second mode from the first mode, wherein
a call is selected for dropping based on relative priorities
associated with the first call and the second call, channel
conditions, quality of service requirements of the first call and
the second call.
5. The method of claim 1, wherein scheduling the single RF transmit
chain comprises: establishing a timesharing schedule for the single
RF transmit chain, wherein the timesharing schedule determines
timing for uplink transmissions associated with the first call and
for uplink transmissions associated with the second call on the
single RF transmit chain.
6. The method of claim 5, wherein scheduling the single RF transmit
chain comprises: controlling a switch provided between a modem and
the single RF transmit chain in accordance with the timesharing
schedule.
7. The method of claim 5, wherein scheduling the single RF transmit
chain comprises: configuring the timesharing schedule based on at
least one of relative priorities associated with the first call and
the second call, channel conditions, and quality of service
requirements of the first call and the second call.
8. The method of claim 1, wherein the first call is established as
a highest priority call and further comprising: gating uplink
transmissions associated with the second call when an uplink
transmission associated with the first call is available.
9. The method of claim 8, wherein the uplink transmissions
associated with the second call that are gated include an ACK
channel transmission.
10. The method of claim 8, wherein gating uplink transmissions
associated with the second call includes: fully gating all ACK
channel transmissions associated with the second call when network
scheduling of the first call requires the ACK channel transmission
associated with the second call to be partially gated.
11. The method of claim 1, wherein the first call is established on
a Global System for Mobile Communications (GSM) network and the
second call is established on a Code Division Multiple Access
(CDMA) network.
12. The method of claim 1, wherein the first call is established on
a Global System for Mobile Communications (GSM) network and the
second call is established on a Universal Mobile Telecommunications
System (UMTS) network.
13. The method of claim 1, wherein the first call is established on
a GSM network and the second call is established on a long-term
evolution (LTE) network configured for time-division duplex LTE
(LTE-TDD/TD-LTE) or frequency division duplex LTE (LTE-FDD).
14. The method of claim 1, wherein the first call is established on
a GSM network and the second call is established on a Code Division
Multiple Access 2000 (cdma2000) Evolution-Data Optimized
network.
15. The method of claim 1, wherein the first call is established on
a GSM network and the second call is established on a cdma2000
1xRTT network.
16. The method of claim 1, wherein the first call is established on
a GSM network and the second call is established on a GSM
network.
17. The method of claim 1, wherein the first call is established on
a GSM network and the second call is established using time
division synchronous code division multiple access (TD-SCDMA).
18. The method of claim 1, wherein the first call is established on
a cdma2000 1xRTT network and the second call is established on an
LTE-FDD or an LTE-TDD/TD-LTE network.
19. The method of claim 1, wherein accepting the second call
comprises: boosting a traffic-to-pilot ratio or increasing overhead
channel gain.
20. The method of claim 1, further comprising: scheduling a single
RF receive chain provided in the access terminal to receive
downlink transmissions associated with the first call and downlink
transmissions associated with the second call.
21. The method of claim 20, wherein scheduling the single RF
receive chain comprises: establishing a timesharing schedule for
the single RF receive chain, wherein the timesharing schedule
determines when networks corresponding to the first call and the
second call are monitored.
22. The method of claim 21, wherein scheduling the single RF
receive chain comprises: controlling a switch provided between a
modem and the single RF receive chain in accordance with the
timesharing schedule.
23. The method of claim 21, wherein scheduling the single RF
receive chain comprises: configuring the timesharing schedule based
on relative priorities associated with the first call and the
second call, channel conditions, or quality of service requirements
of the first call and the second call.
24. The method of claim 20, further comprising: compensating for
phase discontinuities in a pilot signal detected on a network
corresponding to one of the first call and the second call.
25. The method of claim 1, wherein scheduling the single RF
transmit chain or scheduling a single RF receive chain comprises:
dynamically adapting a frequency at which transmitter power of a
number of neighboring transmitters is monitored based on the number
of the neighboring sectors.
26. The method of claim 1, wherein scheduling the single RF
transmit chain or scheduling a single RF receive chain comprises:
decreasing a power monitoring duration for a GSM network.
27. The method of claim 1, wherein scheduling the single RF
transmit chain or scheduling a single RF receive chain comprises:
dropping one or more frames of a speech packet in the uplink
transmissions based on channel conditions.
28. The method of claim 1, wherein scheduling the single RF
transmit chain or scheduling a single RF receive chain comprises:
skipping a portion of a plurality of frames of a speech packet in
downlink transmissions based on channel conditions.
29. The method of claim 1, wherein scheduling the single RF
transmit chain or scheduling a single RF receive chain comprises:
skipping a portion of a plurality of frames of a speech packet in
downlink transmissions when the speech packet is decoded using
early decoding.
30. The method of claim 1, wherein scheduling the single RF
transmit chain or scheduling a single RF receive chain comprises:
substituting silent frames for at least a portion of a plurality of
frames transmitted or received on a GSM network.
31. The method of claim 1, wherein the first call and the second
call are GSM calls, and wherein the first call has a higher
priority than the second call, and wherein the method further
comprises: dropping the second call when the first call and the
second call are allocated a common time slot for communicating on a
GSM network.
32. An access terminal configured for managing multiple
connections, comprising: means for establishing a first call for a
first subscription associated with the access terminal; means for
accepting a second call for a second subscription associated with
the access terminal while maintaining the first call in an active
state; and means for scheduling a single radio frequency (RF)
transmit chain provided in the access terminal for uplink
transmissions associated with the first call and uplink
transmissions associated with the second call when the access
terminal is operating in a first mode.
33. The access terminal of claim 32, wherein the means for
scheduling is configured to: schedule the single RF transmit chain
provided in the access terminal to restrict uplink transmissions to
a single call when the access terminal is operating in a second
mode; and fall back to the second mode from the first mode when one
or more channel conditions are determined, the channel conditions
comprising high network loading, high transmit power or adverse RF
coexistence conditions.
34. The access terminal of claim 33, wherein the first mode is a
dual SIM dual active (DSDA) mode and the second mode is a dual SIM
dual stand-by (DSDS) mode.
35. The access terminal of claim 33, the means for scheduling the
single RF transmit chain is configured to: select either the first
call or the second call to be dropped when the access terminal
falls back to the second mode from the first mode, wherein a call
is selected for dropping based on relative priorities associated
with the first call and the second call, channel conditions,
quality of service requirements of the first call and the second
call.
36. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain is configured to:
establishing a timesharing schedule for the single RF transmit
chain, wherein the timesharing schedule determines timing for
uplink transmissions associated with the first call and for uplink
transmissions associated with the second call on the single RF
transmit chain.
37. The access terminal of claim 36, wherein the means for
scheduling the single RF transmit chain is configured to:
controlling a switch provided between a modem and the single RF
transmit chain in accordance with the timesharing schedule.
38. The access terminal of claim 36, wherein scheduling the single
RF transmit chain comprises: configuring the timesharing schedule
based on at least one of relative priorities associated with the
first call and the second call, channel conditions, and quality of
service requirements of the first call and the second call.
39. The access terminal of claim 32, wherein the first call is
established as a highest priority call and wherein uplink
transmissions associated with the second call are gated when an
uplink transmission associated with the first call is
available.
40. The access terminal of claim 39, wherein the uplink
transmissions associated with the second call that are gated
include an ACK channel transmission.
41. The access terminal of claim 39, wherein the uplink
transmissions that are gated include ACK channel transmissions
associated with the second call, and wherein the ACK channel
transmissions are fully gated when network scheduling of the first
call requires the ACK channel transmission associated with the
second call to be partially gated.
42. The access terminal of claim 32, wherein the first call is
established on a Global System for Mobile Communications (GSM)
network and the second call is established on a Code Division
Multiple Access (CDMA) network.
43. The access terminal of claim 32, wherein the first call is
established on a Global System for Mobile Communications (GSM)
network and the second call is established on a Universal Mobile
Telecommunications System (UMTS) network.
44. The access terminal of claim 32, wherein the first call is
established on a GSM network and the second call is established on
a long-term evolution (LTE) network configured for time-division
duplex LTE (LTE-TDD/TD-LTE) or frequency division duplex LTE
(LTE-FDD).
45. The access terminal of claim 32, wherein the first call is
established on a GSM network and the second call is established on
a Code Division Multiple Access 2000 (cdma2000) Evolution-Data
Optimized network.
46. The access terminal of claim 32, wherein the first call is
established on a GSM network and the second call is established on
a cdma2000 1xRTT network.
47. The access terminal of claim 32, wherein the first call is
established on a GSM network and the second call is established on
a GSM network.
48. The access terminal of claim 32, wherein the first call is
established on a GSM network and the second call is established
using time division synchronous code division multiple access
(TD-SCDMA).
49. The access terminal of claim 32, wherein the first call is
established on a cdma2000 1xRTT network and the second call is
established on an LTE-FDD or an LTE-TDD/TD-LTE network.
50. The access terminal of claim 32, wherein the means for
accepting the second call is configured to: boost a
traffic-to-pilot ratio or increasing overhead channel gain.
51. The access terminal of claim 32, further comprising: means for
scheduling a single RF receive chain provided in the access
terminal to receive downlink transmissions associated with the
first call and downlink transmissions associated with the second
call.
52. The access terminal of claim 51, wherein the means for
scheduling the single RF receive chain is configured to: establish
a timesharing schedule for the single RF receive chain, wherein the
timesharing schedule determines when networks corresponding to the
first call and the second call are monitored.
53. The access terminal of claim 52, wherein the means for
scheduling the single RF receive chain is configured to: control a
switch provided between a modem and the single RF receive chain in
accordance with the timesharing schedule.
54. The access terminal of claim 52, wherein the means for
scheduling the single RF receive chain is configured to: configure
the timesharing schedule based on relative priorities associated
with the first call and the second call, channel conditions, or
quality of service requirements of the first call and the second
call.
55. The access terminal of claim 51, further comprising: means for
compensating for phase discontinuities in a pilot signal detected
on a network corresponding to one of the first call and the second
call.
56. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain or means for scheduling a
single RF receive chain is configured to: dynamically adapt a
frequency at which transmitter power of a number of neighboring
transmitters is monitored based on the number of the neighboring
sectors.
57. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain or means for scheduling a
single RF receive chain is configured to: decrease a power
monitoring duration for a GSM network.
58. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain or means for scheduling a
single RF receive chain is configured to: drop one or more frames
of a speech packet in the uplink transmissions based on channel
conditions.
59. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain or means for scheduling a
single RF receive chain is configured to: skip a portion of a
plurality of frames of a speech packet in downlink transmissions
based on channel conditions.
60. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain or the means for scheduling
the single RF receive chain is configured to: skip a portion of a
plurality of frames of a speech packet to be transmitted when the
speech packet is decoded using early decoding.
61. The access terminal of claim 32, wherein the means for
scheduling the single RF transmit chain or means for scheduling a
single RF receive chain is configured to: substitute silent frames
for at least a portion of a plurality of frames transmitted or
received on a GSM network.
62. The access terminal of claim 32, wherein the first call and the
second call are GSM calls, and wherein the first call has a higher
priority than the second call, and wherein the second call is
dropped when the first call and the second call are allocated a
common time slot for communicating on a GSM network.
63. An access terminal configured for wireless communication,
comprising: a communications interface; and a processing circuit
configured to: establish a first call for a first subscription
associated with the access terminal; accept a second call for a
second subscription associated with the access terminal while
maintaining the first call in an active state; and schedule a
single radio frequency (RF) transmit chain provided in the access
terminal for uplink transmissions associated with the first call
and uplink transmissions associated with the second call when the
access terminal is operating in a first mode.
64. The access terminal of claim 63, wherein the processing circuit
is configured to: schedule the single RF transmit chain provided in
the access terminal to restrict uplink transmissions to a single
call when the access terminal is operating in a second mode; and
fall back to the second mode from the first mode when one or more
channel conditions are determined, the channel conditions
comprising high network loading, high transmit power or adverse RF
coexistence conditions.
65. The access terminal of claim 64, wherein the first mode is a
dual SIM dual active (DSDA) mode and the second mode is a dual SIM
dual stand-by (DSDS) mode.
66. The access terminal of claim 64, wherein the processing circuit
is configured to: select either the first call or the second call
to be dropped when the access terminal falls back to the second
mode from the first mode, wherein a call is selected for dropping
based on relative priorities associated with the first call and the
second call, channel conditions, quality of service requirements of
the first call and the second call.
67. The access terminal of claim 63, wherein the processing circuit
is configured to: establish a timesharing schedule for the single
RF transmit chain, wherein the timesharing schedule determines
timing for uplink transmissions associated with the first call and
for uplink transmissions associated with the second call on the
single RF transmit chain.
68. The access terminal of claim 63, wherein the processing circuit
is configured to: schedule a single RF receive chain provided in
the access terminal to receive downlink transmissions associated
with the first call and downlink transmissions associated with the
second call.
69. The access terminal of claim 68, wherein the processing circuit
is configured to: establish a timesharing schedule for the single
RF receive chain, wherein the timesharing schedule determines when
networks corresponding to the first call and the second call are
monitored.
70. The access terminal of claim 69, wherein the processing circuit
is configured to: control a switch provided between a modem and the
single RF receive chain in accordance with the timesharing
schedule.
71. A processor-readable storage medium having one or more
instructions which, when executed by at least one processing
circuit, cause the at least one processing circuit to: establish a
first call for a first subscription associated with an access
terminal; accept a second call for a second subscription associated
with the access terminal while maintaining the first call in an
active state; and schedule a single radio frequency (RF) transmit
chain provided in the access terminal for uplink transmissions
associated with the first call and uplink transmissions associated
with the second call when the access terminal is operating in a
first mode.
72. The processor-readable storage medium of claim 71, wherein the
instructions cause the at least one processing circuit to: schedule
the single RF transmit chain provided in the access terminal to
restrict uplink transmissions to a single call when the access
terminal is operating in a second mode; and fall back to the second
mode from the first mode when one or more channel conditions are
determined, the channel conditions comprising high network loading,
high transmit power or adverse RF coexistence conditions.
73. The processor-readable storage medium of claim 72, wherein the
first mode is a dual SIM dual active (DSDA) mode and the second
mode is a dual SIM dual stand-by (DSDS) mode.
74. The processor-readable storage medium of claim 72, wherein the
instructions cause the at least one processing circuit to: select
either the first call or the second call to be dropped when the
access terminal falls back to the second mode from the first mode,
wherein a call is selected for dropping based on relative
priorities associated with the first call and the second call,
channel conditions, quality of service requirements of the first
call and the second call.
75. The processor-readable storage medium of claim 71, wherein the
instructions cause the at least one processing circuit to:
establish a timesharing schedule for the single RF transmit chain,
wherein the timesharing schedule determines timing for uplink
transmissions associated with the first call and for uplink
transmissions associated with the second call on the single RF
transmit chain.
76. The processor-readable storage medium of claim 71, wherein the
instructions cause the at least one processing circuit to: schedule
a single RF receive chain provided in the access terminal to
receive downlink transmissions associated with the first call and
downlink transmissions associated with the second call.
77. The processor-readable storage medium of claim 76, wherein the
instructions cause the at least one processing circuit to:
establish a timesharing schedule for the single RF receive chain,
wherein the timesharing schedule determines when networks
corresponding to the first call and the second call are
monitored.
78. The processor-readable storage medium of claim 77, wherein the
instructions cause the at least one processing circuit to: control
a switch provided between a modem and the single RF receive chain
in accordance with the timesharing schedule.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present Application for Patent is a continuation-in-part
of application Ser. No. 14/134,898 entitled "Dual SIM Dual Active
Subscriber Identification Module With A Single Transmit Chain And
Dual Or Single Receive Chain" filed Dec. 19, 2013, which is
assigned to the assignee hereof, and claims priority to Provisional
Application No. 61/856,440 entitled "Dual SIM Dual Active
Subscriber Identification Module With A Single Transmit Chain And
Dual Or Single Receive Chain" filed Jul. 19, 2013, which is
assigned to the assignee hereof, which applications are hereby
expressly incorporated by reference herein.
BACKGROUND
[0002] 1. Field
[0003] Aspects of the present disclosure relate generally to
wireless communication systems, and more particularly, to
management of wireless devices that support multiple
subscriptions.
[0004] 2. Background
[0005] Wireless communication systems are widely deployed to
provide various communication services such as telephony, video,
data, messaging, broadcasts, and so on. Wireless communications
networks, which are usually multiple access networks, support
communications for multiple users by sharing the available network
resources. Examples of such networks include networks based on the
Global System for Mobile Communications (GSM), the Universal Mobile
Telecommunications System (UMTS), and Long Term Evolution (LTE),
which are defined by the 3rd Generation Partnership Project (3GPP),
as well as cdma2000 1x standards including cdma2000 Radio
Transmission Technology (1xRTT) and cdma2000 1xEV-DO
(Evolution-Data only), which are defined by the 3rd Generation
Partnership Project 2 (3GPP2), among others. An LTE network may be
a Time-Division Long-Term Evolution (TD-LTE), also referred to as
Long-Term Evolution Time-Division Duplex (LTE-TDD), as well as
Frequency Division Duplex (FDD) versions of LTE (LTE-FDD).
[0006] Wireless communication systems may be accessed by various
types of devices adapted to facilitate wireless communications,
where multiple devices share the available system resources (e.g.,
time, frequency, and power). Examples of such wireless
communications 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. Multiple types
of devices are adapted to utilize such wireless communications
systems. Such devices may be generally referred to as access
terminals.
[0007] A service provider (or network operator) may deploy multiple
radio access technologies in a given wireless communication system
to enable users of differently capable access terminals to access
the service provider's system. For example, a service provider may
deploy radio access technologies such as a 4th generation (4G) LTE
network, a 3rd generation (3G) Evolution-Data Optimized cdma2000
(EV-DO) network (as defined by the 3GPP2 standards body), cdma2000
1x network (also defined by 3GPP2), a UMTS network utilizing a Time
Division Synchronous Code Division Multiple Access (TD-SCDMA) air
interface or a wideband CDMA (W-CDMA) air interface, and/or a 2nd
generation (2G) network such as GSM.
[0008] In some instances, access terminals may be capable of
communicating on two or more different radio access technologies.
Such access terminals are often referred to as hybrid devices or
hybrid access terminals. One common hybrid access terminal may be
referred to as a 1x/DO hybrid access terminal, which is capable of
communicating on both 3G EV-DO networks and on 2G cdma2000 1x
networks. Another example of a hybrid access terminal may be
referred to as a LTE/DO hybrid access terminal, which is capable of
communicating on both 4G LTE networks and 3G EV-DO networks.
[0009] Certain wireless networks identify subscribed users by means
of a subscriber identity module (SIM). Some wireless devices
support multiple concurrently installed SIMs and may provide a
plurality of transceivers to support concurrent active connects.
Conventionally, a dual active device has two transceivers and may
support two concurrently active connections when two or more SIMs
are installed. The two concurrently active connections may include
some combination of circuit-switched (CS) and packet-switched (PS)
traffic. If two SIMs are active on traffic calls in a dual-active
device, the remaining SIMs generally enter an out-of-service (OOS)
state.
SUMMARY
[0010] The following presents a simplified summary of one or more
aspects of the present disclosure, in order to provide a basic
understanding of such aspects. This summary is not an extensive
overview of all contemplated features of the disclosure, and is
intended neither to identify key or critical elements of all
aspects of the disclosure nor to delineate the scope of any or all
aspects of the disclosure. Its sole purpose is to present some
concepts of one or more aspects of the disclosure in a simplified
form as a prelude to the more detailed description that is
presented later.
[0011] In an aspect of the disclosure, methods, computer program
products, and apparatus are provided that support multiple
concurrent active connections. The apparatus may include a user
equipment (UE), a modem, a transceiver and/or an access
terminal.
[0012] In one aspect, the disclosure provides a method of managing
multiple connections for a wireless device, including the steps of
establishing a first call for a first subscription associated with
an access terminal, accepting a second call for a second
subscription associated with the access terminal while maintaining
the first call in an active state, and scheduling a single radio
frequency (RF) transmit chain provided in the access terminal for
uplink transmissions associated with the first call and uplink
transmissions associated with the second call when the access
terminal is operating in a dual SIM dual active (DSDA) mode.
[0013] In another aspect of the disclosure, the single RF transmit
chain provided in the access terminal may be scheduled to restrict
uplink transmissions to a single call when the access terminal is
operating in a dual SIM dual stand-by (DSDS) mode. The access
terminal may fall back to the DSDS mode from the DSDA mode when one
or more channel conditions are determined The channel conditions
may include high network loading, a high transmit power and/or a
difficult RF co-existence situation. The access terminal may choose
which call should remain active based on priorities of the
calls.
[0014] In another aspect of the disclosure, scheduling the single
RF transmit chain includes establishing a timesharing schedule for
the single RF transmit chain. A switch provided between a modem and
the single RF transmit chain may be controlled in accordance with
the timesharing schedule. The timesharing schedule may determine
timing for the uplink transmissions associated with the first call
and timing for the uplink transmissions associated with the second
call on the single RF transmit chain. Scheduling a single RF
transmit chain may include configuring timesharing schedule for the
single RF transmit chain based on channel conditions and call
priorities.
[0015] In another aspect of the disclosure, the first call is
established as a highest priority call. Uplink transmissions
associated with the second call may be gated when uplink
transmissions associated with the first call are required. The
uplink transmissions associated with the second call that are gated
may include an ACK channel. The ACK channel transmission associated
with the second call may be fully gated when the uplink
transmissions associated with the second call are gated. The ACK
channel transmission associated with the second call may be fully
gated if network scheduling of the first call requires the ACK
channel transmission associated with the second call to be
partially gated.
[0016] In another aspect of the disclosure, the first call is
established on a GSM network and the second call is established on
a GSM network, CDMA network, a UMTS network, an LTE network
(including LTE-FDD, LTE-TDD/TD-LTE networks), a cdma2000 EV-DO
network, a cdma2000 1xRTT network, or a TD-SCDMA network. The first
call may be established on cdma2000 1xRTT network, and the second
call may be established on an LTE network (such as an LTE-FDD,
LTE-TDD, or TD-LTE network).
[0017] In another aspect of the disclosure, wherein accepting the
second call includes boosting a traffic-to-pilot ratio or
increasing overhead channel gain.
[0018] In another aspect of the disclosure, a single RF receive
chain provided in the access terminal is scheduled to receive
downlink traffic associated with the first call and downlink
traffic associated with the second call. The single RF receive
chain may be scheduled by establishing a timesharing schedule for
the single RF receive chain. A switch provided between a modem and
the single RF receive chain may be controlled in accordance with
the timesharing schedule. The timesharing schedule may determine
when networks corresponding to the first call and the second call
are monitored.
[0019] In another aspect of the disclosure, scheduling the single
RF receive chain may include configuring a timesharing schedule for
the single RF receive chain based on channel conditions and call
priorities. Scheduling the single RF receive chain may include
controlling a switch provided between a modem and the single RF
receive chain in accordance with the timesharing schedule.
Scheduling the single RF receive chain may include configuring the
timesharing schedule based on at least one of the relative
priorities associated with the first call and the second call,
channel conditions, or quality of service requirements of the first
call and the second call.
[0020] In another aspect of the disclosure, scheduling the single
RF transmit chain or scheduling the single RF receive chain may
include dynamically adapting a frequency at which transmitter power
of a number of neighboring transmitters is monitored based on the
number of the neighboring sectors. Scheduling the single RF
transmit chain or scheduling the single RF receive chain may
include decreasing a power monitoring duration for a GSM network.
Scheduling the single RF transmit chain or scheduling the single RF
receive chain may include dropping one or more frames of a speech
packet to be transmitted on the uplink based on channel conditions.
Scheduling the single RF transmit chain or scheduling the single RF
receive chain may include skipping a portion of a plurality of
frames of a speech packet to be received on the downlink based on
channel conditions. Scheduling the single RF transmit chain or
scheduling the single RF receive chain may include skipping a
portion of a plurality of frames of a speech packet to be received
on the downlink when the speech packet is decoded using early
decoding. Scheduling the single RF transmit chain or scheduling the
single RF receive chain may include substituting silent frames for
at least a portion of a plurality of frames transmitted or received
on a GSM network.
[0021] In another aspect of the disclosure, the method includes
compensating for phase discontinuities in a pilot signal detected
on a network corresponding to one of the first call and the second
call.
[0022] In another aspect of the disclosure, the first call and the
second call are GSM calls, the first call has a higher priority
than the second call, and the second call may be dropped when the
first call and the second call are allocated a common time slot for
communicating on a GSM network.
[0023] In another aspect of the disclosure, an apparatus adapted to
manage multiple connections for a wireless device, includes means
for establishing a first call for a first subscription associated
with an access terminal, means for accepting a second call for a
second subscription associated with the access terminal while
maintaining the first call in an active state, and means for
scheduling a single RF transmit chain provided in the access
terminal for uplink transmissions associated with the first call
and uplink transmissions associated with the second call when the
access terminal is operating in a first mode. The first mode may be
a DSDA mode. The apparatus may establish a timesharing schedule for
the transmit chain. The timesharing schedule may determine the
timing of uplink transmissions associated with the first call and
when the timing of uplink transmissions associated with the second
call on the transmit chain.
[0024] In another aspect of the disclosure, an apparatus for
wireless communication includes a communications interface, and a
processing circuit configured to establish a first call for a first
subscription associated with an access terminal and accept a second
call for a second subscription associated with the access terminal
while maintaining the first call in an active state, and schedule a
single RF transmit chain provided in the access terminal for uplink
transmissions associated with the first call and uplink
transmissions associated with the second call when the access
terminal is operating in a first mode. The first mode may be a DSDA
mode.
[0025] In another aspect of the disclosure, a processor-readable
storage medium has one or more instructions which, when executed by
at least one processing circuit, cause the at least one processing
circuit to establish a first call for a first subscription
associated with an access terminal, accept a second call for a
second subscription associated with the access terminal while
maintaining the first call in an active state, and schedule a
single RF transmit chain provided in the access terminal for uplink
transmissions associated with the first call and uplink
transmissions associated with the second call when the access
terminal is operating in a first mode. The first mode may be a DSDA
mode.
[0026] These and other aspects of the invention will become more
fully understood upon a review of the detailed description, which
follows. Other aspects, features, and embodiments of the present
invention will become apparent to those of ordinary skill in the
art, upon reviewing the following description of specific,
exemplary embodiments of the present invention in conjunction with
the accompanying figures. While features of the present invention
may be discussed relative to certain embodiments and figures below,
all embodiments of the present invention can include one or more of
the advantageous features discussed herein. In other words, while
one or more embodiments may be discussed as having certain
advantageous features, one or more of such features may also be
used in accordance with the various embodiments of the invention
discussed herein. In similar fashion, while exemplary embodiments
may be discussed below as device, system, or method embodiments it
should be understood that such exemplary embodiments can be
implemented in various devices, systems, and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a block diagram of a network environment in which
one or more aspects of the present disclosure may find
application.
[0028] FIG. 2 is a block diagram illustrating select components of
the wireless communication system of FIG. 1 according to at least
one example.
[0029] FIG. 3 is a schematic diagram illustrating an access
terminal that supports multiple SIMs and connects to a plurality of
networks.
[0030] FIG. 4 is a schematic diagram illustrating a wireless
network including radio access networks operated using different
radio access technologies.
[0031] FIG. 5 is a block diagram illustrating a multi-SIM device
with a single transceiver.
[0032] FIG. 6 is a block diagram illustrating a multi-SIM device
configured for multiple active wireless connections according to
certain aspects disclosed herein.
[0033] FIG. 7 is a block diagram illustrating a transceiver of a
multiple active wireless device that includes two receive chains
and one transmit chain.
[0034] FIG. 8 is a timing diagram illustrating timesharing of a
transmit chain in a multiple active wireless device.
[0035] FIG. 9 is a block diagram illustrating a transceiver that
has one receive chain and one transmit chain and is configured to
support multiple active wireless connections according to certain
aspects disclosed herein.
[0036] FIG. 10 is a flowchart illustrating a method of managing
multiple connections for a wireless device.
[0037] FIG. 11 is a schematic diagram illustrating an apparatus
configured to manage multiple connections in a wireless
network.
DETAILED DESCRIPTION
[0038] In the following description, specific details are given to
provide a thorough understanding of the various aspects of the
disclosure. However, it will be understood by one of ordinary skill
in the art that the aspects may be practiced without these specific
details. For example, circuits may be shown in block diagrams in
order to avoid obscuring the aspects in unnecessary detail. In
other instances, well-known circuits, structures and techniques may
not be shown in detail in order not to obscure the aspects of the
disclosure.
[0039] FIG. 1 is a block diagram illustrating a network environment
in which one or more aspects of the present disclosure may find
application. A wireless communications system 100 is adapted to
facilitate wireless communication between one or more base stations
102 (e.g., 102a and 102b) and access terminals 104. The base
stations 102 and access terminals 104 may be adapted to interact
with one another through wireless signals. In some instances, such
wireless interaction may occur on multiple carriers (waveform
signals of different frequencies). Each modulated signal may carry
control information (e.g., pilot signals), overhead information,
data, etc.
[0040] In this example, the wireless communications system 100
includes two radio access technologies (RATs). The first RAT may
employ base stations 102a that support radio communication for
access terminals 104 located within the coverage of these base
stations 102a. Similarly, the second RAT may employ base stations
102b that support radio communication for access terminals 104
located within the coverage of these base stations 102b. Base
stations 102a and 102b may be located at different sites or
co-located at the same site.
[0041] The base stations 102 (e.g., 102a, 102b) can wirelessly
communicate with the access terminals 104 via a base station
antenna. The base stations 102 may each be implemented generally as
a device adapted to facilitate wireless connectivity (for one or
more access terminals 104) to the wireless communications system
100. Such a base station 102 may also be referred to by those
skilled in the art as a base transceiver station (BTS), a radio
base station, a radio transceiver, a transceiver function, a basic
service set (BSS), and extended service set (ESS), a node B, and
evolved Node B (eNB), a femto cell, a pico cell, or some other
suitable terminology.
[0042] The base stations 102 (e.g., 102a and 102b) are configured
to communicate with the access terminals 104 under the control of a
respective base station controller (see FIG. 2). Each of the base
station 102 sites can provide communication coverage for a
respective geographic area. The coverage area 106 for each base
station 102 here is identified as sectors or cells 106a, 106b and
106c. In various examples, the system 100 may include base stations
102 of different types.
[0043] One or more access terminals 104 may be dispersed throughout
the coverage areas 106. Each access terminal 104 may communicate
with one or multiple base stations 102 at any given moment. In FIG.
1, a solid line with arrows indicates communication between an
access terminal 104 and a base station 102. A dashed line with one
arrow indicates reception of pilot and/or signaling (e.g., pages)
by an access terminal 104 from the base station 102.
[0044] An access terminal 104 may generally include one or more
devices that communicate with one or more other devices through
wireless signals. Such an access terminal 104 may also be referred
to by those skilled in the art as a UE, a mobile station (MS), a
subscriber station, a mobile unit, a subscriber unit, a wireless
unit, a remote unit, a mobile device, a wireless device, a wireless
communications device, a remote device, a mobile subscriber
station, a mobile terminal, a wireless terminal, a remote terminal,
a handset, a terminal, a user agent, a mobile client, a client, or
some other suitable terminology. An access terminal 104 may include
a mobile terminal and/or an at least substantially fixed terminal
Examples of an access terminal 104 include a mobile phone, a pager,
a wireless modem, a personal digital assistant, a personal
information manager (PIM), a personal media player, a palmtop
computer, a laptop computer, a tablet computer, a television, an
appliance, an e-reader, a digital video recorder (DVR), a
machine-to-machine (M2M) device, and/or other
communication/computing device which communicates, at least
partially, through a wireless or cellular network.
[0045] FIG. 2 is a block diagram illustrating select components of
the wireless communication system 100 according to at least one
example. As illustrated, the base stations 102a and 102b are
included as at least a part of a respective radio access network
(RAN) 202a and 202b employing different RATs. The RANs 202a and
202b are generally adapted to manage traffic and signaling between
one or more access terminals 104 and one or more other network
entities, such as network entities included in a core network 204a
or 204b. The RANs 202a and 202b may, according to a particular RAT
implementation, be referred to by those skill in the art as a BSS,
an access network, a GSM Edge Radio Access Network (GERAN), a UMTS
Terrestrial Radio Access Network (UTRAN), etc.
[0046] In addition to one or more base stations 102a or 102b, each
RAN 202a and 202b can include at least one respective base station
controller (BSC) 206a, 206b, which may also be referred to by those
of skill in the art as a radio network controller (RNC). The BSCs
206a, 206b are generally responsible for the establishment,
release, and maintenance of wireless connections within one or more
coverage areas associated with the base stations 102a, 102b
connected to the BSC 206A, 206B.
[0047] The BSCs 206a, 206b can be communicatively coupled to one or
more nodes or entities of the respective core networks 204a, 204b.
Each core network 204a, 204b provides access to a public switched
telephone network (PSTN) (e.g., via a mobile switching
center/visitor location register (MSC/VLR)) and/or to an IP network
(e.g., via a packet data switching node (PDSN)) 208a, 208b.
[0048] The first RAN 202a may use a first RAT, which may utilize
any suitable technology including but not limited to GSM, UMTS,
LTE, cdma2000 1x, EV-DO, etc., and the second RAN 202b may use a
second RAT that may similarly utilize any suitable technology
including but not limited to GSM, UMTS, LTE, cdma2000 1x, EV-DO,
etc. In one non-limiting example provided for ease of description,
the first RAT implemented by the first RAN 202a may comply or be
compatible with the cdma2000 1x standard, while the second RAT
implemented by the second RAN 202b may comply or be compatible with
EV-DO communication standard. In another example, the first RAN
202a may be implemented using a 3G RAT such as EV-DO, while the
second RAN 202b may be implemented using a 4G RAT such as LTE. As
noted previously, the various features described herein may be
employed with any combination of a number of different
communications standards.
[0049] As depicted in FIG. 1, the coverage areas of the two or more
RANs 202a, 202b employing different RATs may overlap within a
geographical region. In such instances, the access terminals 104
may be under the coverage of a plurality of the RANs 202a, 202b at
any given moment. When one or more of the access terminals 104 are
implemented as hybrid access terminals 104, such hybrid access
terminals 104 may be capable of accessing either or both of the
RANs 202a, 202b at any given moment.
[0050] Typically, it is desirable for a hybrid access terminal 104
to conduct a data session on whichever RAN 202a, 202b provides the
fastest data transmission speeds in order to provide a relatively
better user experience. As used herein, the faster or otherwise
more desirable RAN will be referred to as the "preferred RAN," and
the less desirable RAN will be referred to as the "secondary
RAN."
[0051] A hybrid access terminal 104 utilizing the secondary RAN is
typically adapted to search for certain frequencies that are
transmitted by the preferred RAN. The hybrid access terminal 104
may maintain a list of frequencies to monitor in a table, database,
and/or in storage. The list of frequencies may be provided by one
or more RANs 202a, 202b and/or may include frequencies previously
detected or used by the hybrid access terminal 104. During a call
with a secondary RAN, or at any other time, the hybrid access
terminal 104 may monitor various parameters of the secondary RAN as
well as various parameters of neighboring RANs. Further, depending
on the quality of these parameters, the hybrid access terminal 104
may maintain communication with one or more of the neighboring
RANs.
[0052] FIG. 3 is a diagram illustrating an access terminal 302
adapted to operate concurrently in multiple networks. The multiple
networks may include networks employing one or more of a GSM,
UTRAN, LTE, cdma2000 1x, EV-DO architecture. The access terminal
302 may receive services provided by the core networks 314 and 316.
The access terminal 302 may communicate with a first access point
304 to obtain services from a first network 314. The access
terminal 302 may communicate with a second access point 306 to
obtain services from a second network 316. The access terminal 302
may obtain services from a single core network 314 or 316 through
two or more access points 304, 306 and/or 308. For example, the
access terminal 302 may communicate with the second access point
306 and the third access point 308 to obtain services from the
second network 316. Each network 314 and 316 may provide voice
and/or data services through one or more RANs operated by the same
or different network operators.
[0053] The access terminal 302 may be adapted or configured to
support two or more SIMs 328 that can be used to identify and
authenticate subscribed users of the different services offered by
operators of the core networks 314, 316. In one example, each SIM
328 may store an IMSI 326 and related keys that can uniquely
identify and authenticate a user of the access terminal 302 and
subscribed services available to the user through the networks 314
and/or 316. Each SIM 328 may be associated with a telephone number
or other network identifier different from telephone numbers or
other identifiers associated with the other SIMs 328. In one
example, the access terminal 302 is a mobile telephone device
equipped with two or more SIMs 328 that enable the establishment of
calls on two or more different voice and/or data networks, and to
maintain two or more active calls concurrently. The use of multiple
SIMs 328 may permit a user of the access terminal 302 to access and
use features of different subscriptions to reduce costs, obtain
superior service, etc.
[0054] The access terminal 302 may support a variety of operational
modes when multiple SIMs 328 are installed in the access terminal
302. For example, in dual SIM dual stand-by (DSDS) mode, the access
terminal 302 may initially be in standby mode for two different
subscriptions. After establishing a call through one network 314 or
316, the access terminal 302 may cause the connection between the
access terminal 302 and the other networks 316 or 314 to enter an
inactive state.
[0055] In dual SIM dual active (DSDA) mode, the access terminal 302
may be concurrently connected to two different subscribed networks
314 and 316. A DSDA-enabled access terminal 302 may be capable of
switching between two simultaneously active calls and/or connecting
two active calls at the access terminal 302. In DSDA mode, the
access terminal 302 may establish a first active call on a first
subscribed network 314, while remaining idle on a second subscribed
network 316. While a call is active on a first subscribed network
314 or 316, a DSDA-enabled access terminal 302 may receive a second
call through a second subscribed network 316 or 314. If calls are
simultaneously active on the first and second subscribed networks
314 and 316, a user may switch between the two calls as desired,
and/or may connect the two calls at the access terminal 302. When
more than two SIMs 328 are installed in the access terminal 302,
other modes of operation may be defined, including triple SIM dual
active (TSDA) mode, quad SIM dual active (QSDA) mode, for
example.
[0056] A DSDA-enabled access terminal 302 may include two or more
radio frequency (RF) transceivers 322 and 324. Each RF transceiver
322 and 324 may be operated independently and used for establishing
and maintaining an active connection with an access point 304, 306,
or 308 on behalf of subscriptions for a corresponding number of
installed SIMS 328. The RF transceivers 322, 324 may be embodied in
one or more RF modems and each transceiver 322 and 324 includes
both a transmit (Tx) chain and a receive (Rx) chain. An RF modem
may assign an Rx chain and a Tx chain for each RF transceiver 322,
324. Tx chains may include modulators, encoders, power amplifiers
and other devices and circuits. Rx chains may include amplifiers,
demodulators, decoders and other devices and circuits. Certain
devices and circuits may be sharable between Rx chains. In the
example depicted in FIG. 3, the access terminal 302 has two RF
transceivers 322, 324 with dedicated Rx and Tx chains configured to
support concurrent connections to different access points 304 and
306 corresponding to networks 314 and 316, respectively. An RF
modem may additionally include one or more processors,
non-transitory storage and logic configured to process, transmit
and receive signals, and to encode and decode data transmitted and
received by the access terminal 302.
[0057] In triple SIM dual active (TSDA) mode, the access terminal
302 may support three subscriptions but can be connected to only
two different ones of access points 304, 306, 308 concurrently. In
quad SIM dual active (QSDA) mode, the access terminal 302 may
support four subscriptions but can be concurrently connected to
only two different ones of access points 304, 306, 308. Typically,
TDSA or QSDA modes are employed when the access terminal 302 is
provided with only two RF chains 322 and 324 in order to optimize
power consumption of the access terminal 302.
[0058] FIG. 4 is a block diagram 400 illustrating a simplified
example of a wireless internetworking environment. An access
terminal 402 may be associated with one or more access points 404,
410 that may be operated by the same or different network operators
and that may operate using the same or different network
technologies. The access point 404 and/or 410 may include, or be
referred to, as a base station, a base transceiver station, a radio
access point, an access station, a radio transceiver, a BSS, an
ESS, a Node B, an eNB, or some other suitable terminology. Each
access point 404, 410 may provide a radio interface in a RAN that
provides access to core network services provided by one or more
network operators. RANs may be implemented using any suitable RAT
and telecommunication standards employing a variety of modulation
and multiple access techniques. By way of example, RANs associated
with access points 404, 410 may include one or more networks based
on UTRAN, GSM, LTE, Evolved UTRA (E-UTRA) network, IEEE 802.11
(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and /or Flash-OFDM
employing OFDMA. RANs may also include one or more cdma2000
networks or its variants such as cdma2000 1xRTT (also referred to
as 1xRTT herein), EV-DO networks, including Ultra Mobile Broadband
(UMB) networks.
[0059] In the depicted example, the access terminal 402 may be
associated with a PS network, such as LTE, through an eNB 404, and
the access terminal 402 may be associated with a CS network for
data and voice calls through the base station 410. The access
terminal 402 may be registered with an E-UTRAN (through the eNB
404) and a packet data network (PDN) gateway 410 may provide
connectivity between the access terminal 402 and one or more
external packet data networks 416. The access terminal 402 may be
registered with a CS network, such as a 1xRTT network, through base
station 410 in order to obtain voice and data services through a
cdma2000 network.
[0060] GPRS permits 2G, 3G and W-CDMA mobile networks to transmit
Internet Protocol (IP) packets to external networks such as the
Internet 416 using a gateway function, which may include an SGSN
414. The SGSN 414 may provide certain interworking services
enabling communication between the GPRS system and an external
packet switched network 416. Certain aspects of the invention are
equally applicable to other combinations of PS and CS networks,
including GSM, LTE cdma2000 1x, and/or EV-DO, for example.
[0061] In the example depicted in FIG. 4, the MME 406 serves as a
control node for LTE traffic related to the access terminal 402.
The MME 406 typically processes signaling between the access
terminal 402 and a core network, providing bearer and connection
management services. In some embodiments, an interworking server
(IWS) 408 may perform a single radio voice call continuity
interworking solution function between UTRAN and E-UTRAN access
networks. Accordingly, backhaul communications may be available
between LTE and 1x networks, and other combinations of network
types and technologies. The mobile switching center (MSC) 412 may
control network switching elements used in the provision of 1xRTT
voice services through base station 410.
[0062] The access terminal 402 may be deployed in a location where
multiple accessible cells or RANs are available and the access
terminal 402 may use different frequencies and/or different RATs to
access a core network that provides mobility management, session
management, transport for IP packet services, and other services.
RATs may be based on UMTS, TD-SCDMA, GSM, cdma2000 and/or WiMAX,
for example.
[0063] FIG. 5 is a simplified block diagram 500 illustrating a
multi-SIM access terminal 502 according to certain aspects
disclosed herein. The access terminal 502 may be equipped with a
transceiver 512 that has fewer available Rx chains 516a and/or Tx
chains 516b than the number of desired active connections. In one
example, the access terminal 502 may communicate wirelessly through
one Rx chain 516a and one Tx chain 516b and associated RF
interfaces 524a, 524b, which may include RF amplifiers, antennas
and other RF circuitry and components. In another example, the
access terminal 502 may have idled one or more other transceivers
or one or more Rx chains 516a and/or Tx chains 516b of the
transceiver 512 in order to conserve power. The access terminal 502
may have multiple transceivers 512, but for ease of description,
certain systems, methods and techniques disclosed herein may be
described in context of an access terminal 502 that is constructed
with a single transceiver 512 that includes a limited number of
available Rx chains 516a and Tx chains 516b.
[0064] The access terminal 502 may be configured to receive
services provided by one or more core networks 520, 522. In one
example, the access terminal 502 may obtain services from a first
network 520 through a first access point 504 and may obtain
services from a second network 522 through a second access point
506. The access terminal 502 may obtain services from a single core
network 520 or 522 on behalf of two different subscriptions 508a
and 508b. Each core network 520 and 522 may provide voice services,
data services or some combination of voice and data services
through one or more RANs operated by the same or different network
operators.
[0065] The access terminal 502 may be adapted or configured to
support two subscriptions 508a and 508b, where the subscriptions
are identified or otherwise correspond to SIMs 518a, 518b installed
in the access terminal 502. A subscription manager 510 may be
provided to manage the subscriptions 508a, 508b associated with the
SIMs 518a and 518b. The subscription manager 510 may be implemented
in a combination of hardware circuitry and software/firmware
modules or other logic elements, and the operation of the
subscription manager 510 may be controlled by the processing
circuit 514.
[0066] The SIMs 518a and 518b can be used to identify and
authenticate subscribed users of the various services offered by
network operators. In one example, each SIM card 518a, 518b may
store an IMSI and related keys that can uniquely identify and
authenticate a subscribed user of the access terminal 502. Each SIM
card 518a, 518b may enable access to subscribed services available
to the user through the networks 520 and/or 522. Each subscription
508a or 508b may be associated with a telephone number or another
network identifier, and the two subscriptions 508a and 508b
typically include different telephone numbers or identifiers. In
one example, the access terminal 502 may be a mobile telephone
device equipped with two or more SIMs 518a, 518b that enable the
establishment of traffic calls on two or more different voice
and/or data networks. The access terminal 502 may be adapted or
configured to maintain two or more concurrently active calls.
[0067] The access terminal 502 may be adapted or configured to
support one or more multiple-active operational modes as disclosed
herein to support network access for multiple subscriptions when
the access terminal 502 has fewer RF transceivers 512 or fewer Rx
chains 516a and/or Tx chains 516b than the available or desired
number of connections. According to certain aspects disclosed
herein, an enhanced dual SIM dual standby (eDSDS) mode may be
defined whereby the access terminal 502 may be configured to
receive calls for the second subscription 508b when a call for the
first subscription 508a is active on the access terminal 502. When
a first call is active on the access terminal 502 and a second call
is indicated, a user of the access terminal 502 may determine
whether the second call should be accepted or declined, even when
there are fewer than two Rx chains 516a and/or two Tx chains 516b.
The user may determine whether to accept the second call based on
caller identification (Caller ID), for example. A declined voice
call may be sent to voicemail, forwarded to another device,
dropped, or otherwise deferred. In devices that support
conventional DSDS, a voice call received for a second subscription
508b is automatically sent to voicemail, or otherwise forwarded or
deferred when a call for the first subscription 508a is active.
[0068] In another example, the access terminal 502 may be
configured to support a simultaneous dual SIM dual active (sDSDA)
mode whereby the access terminal 502 may support two traffic calls
simultaneously, using a single transceiver 512 that may have a
single or dual Rx chains 516a and a single Tx chain 516b. The
access terminal 502 may maintain a voice call for each of the two
subscriptions 508a and 508b, with one of the two voice calls being
placed on hold. The user may determine which of the two voice calls
should be active, and which voice call should be placed on hold. In
another example, such as an example corresponding to simultaneous
voice and LTE, or SVLTE, the access terminal 502 may maintain a
voice call for one of the two subscriptions 508a or 508, while a
data connection is maintained for the other subscription 508b or
508a. In devices that support conventional DSDS, a data connection
is automatically dropped when a voice call is received or
active.
[0069] FIG. 6 illustrates an example of an access terminal 602 that
may be configured to provide the eDSDS and sDSDA modes described
herein. The access terminal 602 may include two Rx chains 616a and
616b and one Tx chain 616c. Each of the two Rx chains 616a and 616b
may be assigned to handle downlink communications for one of two
active subscriptions 608a or 608b. The subscriptions 608a and 608b
may have access to the Tx chain 616c on a timeshared basis.
Timeshare logic 620 may be used to provide timeshared access to the
Tx chain 616c, under the control and management of the modem 614
and/or the processing circuit 618 in cooperation with the
subscription manager 610 and components of the transceiver 612.
Timeshare logic 620 may act as a switch and may be logically or
physically provided within a modem 614, between the modem 614 and a
Tx chain 616c, or between the modem 614 and an RF card or
device.
[0070] Elements of the timeshare logic 620 may be provided within
the modem 614, the transceiver 612 or the Tx chain 616c. The
timeshare logic 620 may be provided between the modem and an RF
card, within the RF card, or elsewhere within the access terminal
602. In some examples, the timeshare logic 620 may include one or
more modules provided in the modem 614, the processing circuit, the
manager 610 and/or the transceiver 612, where the one or more
modules control and configure a logical or physical data path
through the modem 614 and the transceiver 612. In one example, the
timeshare logic 620 may be implemented as a state machine whereby
different states determine access to the shared Tx chain 616c. In
another example, a module of the processing circuit 618 may
configure the modem 614 to block data related to one subscription
608a, 608b and to pass data related to the other subscription 608b,
608a to the transceiver 612.
[0071] In some instances, a plurality of Rx chains 616a and 616b is
provided within the transceiver 612 such that the access terminal
602 may concurrently monitor and receive downlink communications
for each subscription 608a and/or 608b, while the Tx chain 616c is
timeshared. In another example, the access terminal 602 may provide
a single active Rx chain 616a or 616b and a single Tx chain 616c,
and the access terminal 602 may apply timesharing to both the
active Rx chain 616a or 616b and the Tx chain 616c when two traffic
calls are active for the two subscriptions 608a and 608b. While
certain devices may have multiple transceivers 612 and/or multiple
Rx chains 616a, 616b and Tx chains 616c that can be selectively and
individually disabled, certain advantages may accrue when the
access terminal 602 has a limited number of Rx chains 616a, 616b
and Tx chains 616c. For example, fewer RF circuits and other
devices may be required when the number of transceivers 612 and/or
Rx chains 616a, 616b and Tx chains 616c is limited, leading to
reduced cost of manufacture, reduced power consumption and more
compact circuit boards.
[0072] FIG. 7 is a simplified schematic block diagram 700
illustrating a transceiver 702 that may be provided in the access
terminal 602 (see FIG. 6). The transceiver 702 includes two Rx
chains 704a and 704b and a single Tx chain 706. The Rx chains 704a
and 704b and the Tx chain 706 may be coupled to one or more
antennas 710. The transceiver 702 may be configured to support the
eDSDS mode and/or sDSDA mode operation disclosed herein. In one
example, the transceiver 702 may concurrently maintain a connection
with a first network for a first subscription 708a and a connection
with a second network for a second subscription 708b. In one
example, the first network may be implemented using 1xRTT, EV-DO,
W-CDMA, LTE, GSM, etc., while the second network may be implemented
using GSM, for example. In the illustrated example, the access
terminal 602 may monitor downlink communications for both
subscriptions 708a, 708b on the separate Rx chains 704a and 704b.
On the uplink, the access terminal 602 may cause the subscriptions
708a and 708b to share the Tx chain 706.
[0073] Timeshare logic 712 may be operated according to a
timesharing schedule that determines when the transmit chain 616c
is allocated for use of two or more subscriptions 608a, 608b. The
timesharing circuit 712 may be a component of the transceiver 702
or of another component, module or device within a modem, between
the modem and an RF card, within the RF card, or elsewhere within
the access terminal 602. In one example, a timesharing scheme may
be implemented using timeshare logic 712 that may be configured to
buffer data and subsequently transmit buffered data according to a
timesharing schedule. In another example, the timesharing schedule
may allocate uplink time slots that enable the access terminal 602
to transmit and receive control information for each of the two
active connections. The timesharing schedule may prioritize the
connections and allocate uplink time slots for data transmission
according to the prioritization.
[0074] In some examples, the timesharing schedule can be
dynamically changed. The timesharing schedule may be modified based
on channel conditions and call priorities. For example, the
timesharing schedule may favor a voice call established for a first
subscription 708a when a data call is established for the second
subscription 708b and a user of the access terminal 602 is
physically located at an edge of a cell of a network in which the
voice call has been established. In the latter example, a
timesharing schedule may be configured to provide more transmission
and/or reception time for the voice call at the penalty of data
call performance. In other examples, a timesharing schedule may be
dynamically adapted to give preference to one of two calls based on
quality of service requirements associated with the calls, identity
of the networks or network providers, radio access technology used
to establish and maintain calls, roaming status, and other
priorities associated with the calls.
[0075] According to certain aspects, the timesharing circuit 712
may operate to gate, delay or blank transmissions related to one
subscription 708a or 708b when the other subscription 708b or 708a
has information to be transmitted. In one example, the access
terminal 602 may suspend or gate transmissions related to a
connection with the first network, which may be a 1xRTT, EV-DO,
W-CDMA, LTE or GSM network, in order to accommodate transmissions
associated with the second network, which may be a GSM network, for
example.
[0076] In a further aspect of the disclosure, the access terminal
602 may make certain transmit power adjustments in order to support
timesharing on the uplink. For example, the traffic-to-pilot (T2P)
power ratio for a channel may be boosted and/or certain power
control information may be specially processed, given that two
subscriptions have been provisioned for the access terminal 602. In
another example, an overhead channel gain may be increased. In
another example, an ACK channel may be blanked as desired or
necessary.
[0077] In certain examples, the access terminal 602 may revert to
conventional behavior according to a fallback protocol or procedure
when blanking or gating transmissions on the uplink for the first
or second network becomes difficult to sustain. For example,
blanking and/or gating transmissions may become inoperable when
very high transmit power is required in 1xRTT, EV-DO, CDMA
(including W-CDMA) and LTE networks at the edge of one or more
cells. Fallback may include idling or disconnecting one of two
current connections and redirecting further voice calls for the
subscription 708a or 708b associated with the idled connection to
voicemail. Fallback may also occur when extreme RF co-existence
issues arise. Fallback may include reverting to DSDS modes of
operation and/or adopting protocols and behaviors consistent with
DSDS modes of operation.
[0078] FIG. 8 is a simplified timing diagram 800 illustrating
timesharing of a Tx chain 706 (see FIG. 7). For the purposes of
facilitating this description only, it will be assumed that a
network connection associated with the second subscription 708b has
a higher priority than the network connection associated with the
first subscription 708a. In the example, the access terminal 602
may transmit control information for the first subscription 708a in
a first series of time slots 802 and 814, and may transmit control
information for the second subscription 708b in a second series of
time slots 804. The access terminal 602 may suspend or gate active
transmission of traffic 806 and 810 for the first subscription 708a
when traffic and/or control data becomes available for transmission
in one or more slots 804, 808, 812 from the second subscription
708b.
[0079] FIG. 9 is a simplified schematic block diagram 900
illustrating a transceiver 910 in an access terminal 602 that has a
single Rx chain 904 and a single Tx chain 906. In this example, the
transceiver is depicted as a component of a modem 902, although the
principles and/or aspects described herein apply equally to
examples where some or all of the circuits of the transceiver 910
may be provided separately or externally of the modem 902. For
example, one or more of the transmit timeshare logic 912 and the
receive timeshare logic 914 may be provided between separate modem
devices or circuits and transceiver devices or circuits.
[0080] Timeshare logic 912, 914 may switch between subscriptions
908a and 908b, in accordance with a timeshare schedule. The
transmit timeshare logic 912 may be configured to drop one or more
frames, slots or packets related to a first call when the second
call is scheduled to have access to the transmit chain 906. In one
example, one or more packets associated with a voice call may be
dropped when the packets have sufficient redundancy. Similarly, the
receive timeshare logic 914 may be configured to skip one or more
frames, slots or packets related to a first call when the second
call is scheduled to have access to the receive chain 904.
[0081] The Rx chain 904 and the Tx chain 906 may be coupled to one
or more antennas 916. The transceiver 910 may be configured to
support the eDSDS mode of operation and/or sDSDA mode of operation
disclosed herein. In one example, the transceiver 910 may maintain
concurrent connections with a first network for a first
subscription 908a and with a second network for a second
subscription 908b. The first network may be implemented using
1xRTT, EV-DO, W-CDMA, LTE, GSM, etc., while the second network may
be implemented using GSM, for example.
[0082] The access terminal 602 may monitor downlink communications
for both subscriptions on the same Rx chain 904. In one example,
the access terminal 602 may monitor the downlink connections
according to a coordinated paging schedule. In some instances, the
access terminal 602 may monitor both links simultaneously, when
both subscriptions 908a and 908b have acquired the same network and
cell.
[0083] Timeshare logic 914 may be provided to coordinate downlink
activities, and to direct control information and traffic to the
appropriate subscription 908a or 908b. The timeshare logic 914 may
be a component of the modem 902, the transceiver 910, or of another
component, module, circuit or device within a modem, between the
modem and an RF card, within the RF card, or elsewhere within the
access terminal 602. The timeshare logic 914 may provide timeshared
access to the Rx chain 904, under the control and management of a
processing circuit of the modem 902 or another component of the
access terminal 602. Timeshare logic 914 may act as a switch.
Timeshare logic 914 may include one or more modules of a processing
circuit, the modem 902 and/or the transceiver 910, where the one or
more modules control and configure a logical or physical data path
through the modem 902 and the transceiver 910. In one example, the
modem 614 may be configurable to block data related to one
subscription 608a, 608b and to pass data related to the other
subscription 608b, 608a to the transceiver 612.
[0084] The access terminal 602 may be configured or adapted to
handle apparent signaling discontinuities due to timesharing of a
single Rx chain 904. For example, discontinuities may occur in
pilot signals when the use of the Rx chain 904 switches between a
first subscription and a second subscription, where the two
subscriptions use different RATs, or different channels in the same
RAT. One or more processing circuits that handle configuration and
control information associated with a first subscription 908a or
908b may be adapted to accommodate disruptions in the reception of
signaling directed to the first subscription 908a or 908b while the
time sharing circuit or module 914 is permitting the second
subscription 908b or 908a access to the Rx chain 904. For example,
pilot and/or media access control (MAC) message processing may be
halted as needed to support switching between connections.
Moreover, phase discontinuities may be introduced in pilots due to
the operation of the timesharing circuit or module 914, and special
pilot processing may be required to recognize and correct for such
phase discontinuities. For certain RATs, special preamble detection
handlers and/or rate control loop handlers may be employed.
[0085] On the uplink, the access terminal 602 may share the Tx
chain 906. A timesharing scheme may be implemented using timeshare
logic 912 that may be configured as a switch. The timeshare logic
912 may be configured to buffer and transmit buffered data
according to a predefined schedule. The timesharing module 912 may
be a component of the transceiver 910 or of another component,
module or device within a modem, between the modem and an RF card,
within the RF card, or elsewhere within the access terminal 602.
Timeshare logic 912 may act as a switch and may be logically or
physically provided within the modem 902, or between the modem 902
and the Tx chain 906. Timeshare logic 912 may be embedded within
the Tx chain 906. Timeshare logic 912 may include one or more
modules of a processing circuit, the modem 902 and/or the
transceiver 910, where the one or more modules control and
configure a logical or physical data path through the modem 902 and
the transceiver 910. In one example, timeshare logic 912 may
configure the modem 902 to block data related to one subscription
908a, 908b and to pass data related to the other subscription 908b,
908a to the transceiver 910.
[0086] According to certain aspects, the uplink timesharing module
912 may operate to gate, delay or blank transmissions related to
one subscription 908a or 908b when the second subscription 908b or
908a has information to be transmitted. In one example, the access
terminal 602 may suspend or gate transmissions related to a
connection with the first network in order to accommodate
transmissions associated with the second network, when the
connection with the second network is assigned a higher priority.
Certain transmit power adjustments may be required to support
timesharing on the uplink. For example, the T2P power ratio for a
channel may be boosted and certain power control information may be
ignored, given that two subscriptions have been provisioned for the
access terminal 602. Certain combinations of connections may not be
amenable to partial gating or blanking. For example, partial
blanking may be precluded when two networks are substantially
scheduled such that timing of data transmission on one call may
correspond with an ACK channel scheduled on a second call. In the
latter example, performance degradation due to partially gating of
an ACK channel may be higher than the performance degradation due
to a completely gated ACK channel.
[0087] According to certain aspects, the access terminal 602 may
revert to conventional behavior for both the uplink and downlink
connections, and in accordance with a fallback protocol or
procedure when blanking or gating transmissions on an uplink for a
first or second network becomes difficult to sustain. Fallback may
also occur when extreme co-existence issues arise and/or when
certain channel conditions, including high loading or high transmit
power arise. For example, blanking and/or gating transmission may
become inoperable when very high transmit power is required in
1xRTT, 1xEV-DO, W-CDMA, TD-SCDMA and LTE networks. High transmit
power may be required at a cell edge. Fallback may include idling
one of two current connections and redirecting further voice calls
to voicemail. Fallback may include reverting to DSDS mode and/or
adopting protocols and behaviors consistent with DSDS mode. When
falling back to DSDS mode, different RATs may compete based on
their priority and other characteristics and factors. For example,
priorities may be determined based on the type of call, the type of
network, quality of service requirements associated with a call,
and so on. In some instances, a call that is experiencing quality
and/or power issues, such as a call connected from the edge of a
cell, may be assigned a lower priority.
[0088] According to certain aspects disclosed herein, an access
terminal 502 (see FIG. 5) that is adapted or configured for eDSDS
and/or sDSDA may be further configured to adapt its behavior to
modify, enhance or enable timesharing schemes when the active
connections include one or more connections with a GSM network 520
and/or 522.
[0089] For example, the power monitoring duration used in a GSM
network 520 and/or 522 may be reduced to occupy less than a
complete GSM time slot. The power monitoring duration may be
restricted to a portion of the complete time slot. In one example,
power monitoring may be limited to a 327 .mu.s period.
[0090] The frequency of power monitoring during a traffic state may
be reduced. In a conventional GSM network 520 and/or 522, the
frequency of power monitoring may be set to accommodate up to 32
neighboring cells. The access terminal 502 may adaptively configure
the frequency based on the number of neighbors detected by the
access terminal 502 or an expected maximum number of neighbors to
be measured. Typically, the access terminal 502 can detect 16 or
fewer neighbors that should be monitored and the frequency of power
monitoring can be modified accordingly.
[0091] An access terminal 502 that is adapted or configured for
eDSDS and/or sDSDA may be further configured to perform wideband
power scans and power monitoring to reduce power monitoring
overhead. The access terminal 502 may be configured to search
across multiple RATs for cells or sectors of a RAN that can provide
service to the access terminal 502. The extent of the search may be
significantly increased when different RATs are involved. For
example, service from a GSM network may be provided in one of
several hundred channels, and a search for an absolute radio
frequency number (ARFCN) in a GSM network may take significant
time, particularly where access to a single Rx chain 516a is shared
between subscriptions 508a and 508b in an access terminal 502. When
the access terminal is configured to scan networks that use
different RATs, the task of searching becomes even more
onerous.
[0092] An access terminal 502 that is adapted or configured for
eDSDS and/or sDSDA may be equipped with a transceiver 512 that
provides a wideband receiver and/or plural local oscillators that
can be used for rapid scanning for carrier frequencies associated
with one or more RATs. The wideband receiver and/or local
oscillators may be used to analyze power distribution in a wide
spectrum of frequencies associated with different RATs using signal
processing circuits and modules such as fast Fourier transform
(FFT) circuits and processors. In one example, the search may yield
a power distribution that indicates the presence of signals of
interest at one or more carrier frequencies of a supported RAT. An
FFT processor and other circuits may perform a narrowband analysis
around signals of interest in an order determined by the relative
power of the signals of interest.
[0093] In another aspect, certain types of data may be decoded
without receiving every frame or slot used to transmit the data.
For example, audio data transmitted on a GSM network typically
includes speech encoded using an Adaptive Multi-Rate (AMR) audio
codec that operates according to an audio data compression scheme
optimized for speech coding. The AMR codec may produce toll quality
speech data rates of 7.4 kbit/s. The AMR codec may use link
adaptation to select from one of eight bit rates based on link
conditions. Accordingly, there may be sufficient redundancy in
voice packets after encoding for transmission to drop a GSM slot or
frame without losing the ability to decode the complete voice
signal. A voice packet may be decoded even if data in the voice
transmission is not transmitted and, in some instances, the access
terminal 602 that is adapted or configured for eDSDS and/or sDSDA
operation may be able to drop up to 1 out of every 4 frames when
the AMR codec is producing full-rate downlink or uplink speech
data.
[0094] According to certain aspects disclosed herein, slots and/or
frames may be dropped by the access terminal 602 when there is
sufficient margin in the encoded voice packet to permit early
decoding. Early decoding provided in GSM networks can increase
system capacity and reduce receiver power consumption. In one
example, early decoding may be used for decoding a message on a
control channel in a wireless communication system, where the
control channel may be a common control channel (CCCH), a paging
channel (PCH) or a broadcast control channel (BCCH) in a GSM
system. Early decoding may be used in other RATs. Early decoding
can be performed when a message is encoded and partitioned into
multiple data blocks that are transmitted at different times if a
portion of the multiple data blocks include sufficient information
to recover the complete message. For example, a paging message
transmitted in a GSM network may be encoded and partitioned into
four blocks, which are transmitted as four bursts. The complete
message may be recovered at the receiving access terminal 602 from
two or more bursts, depending on channel conditions.
[0095] The receiving access terminal 602 in a GSM network may
determine when the complete message has been decoded based on error
detection elements transmitted in the message. The access terminal
602 may go to sleep upon early decoding of the complete message,
thereby conserving battery power and extending standby time of the
access terminal If the access terminal 602 is unable to decode the
complete message after receiving two bursts, the access terminal
602 may receive a third burst and access terminal 602 may go to
sleep if the complete message can be decoded from the three bursts.
Normal decoding is performed if the message cannot be decoded from
less than four bursts in this example. In another example, an
access terminal 602 that is adapted or configured for eDSDS and/or
sDSDA operation may drop one or more GSM slots associated with a
voice packet when the voice packet has sufficient redundancy to
permit early decoding.
[0096] The access terminal 602 that is adapted or configured for
eDSDS and/or sDSDA operation may maintain two active calls, where
one of the calls, such as a GSM call, is placed on hold. Certain
characteristics of an on-hold call are different from a call in
which there is no speech activity. For example, one or more
signaling tones may be transmitted for a GSM call that is on-hold,
whereas the active call with no speech activity may have nothing
but noise to transmit, which may result in lower power transmission
than the power associated with the transmission of tones
corresponding to an on-hold call. In certain instances, the access
terminal 602 that is adapted or configured for eDSDS and/or sDSDA
may provide a structured signal to the voice encoder for the
"on-hold" call to obtain low-power silent frames for transmission
in place of frames that transmitted with signaling tones when a GSM
call is on hold. The silent frames may be substituted for all or a
portion of frames that carry the tones.
[0097] In certain instances, additional blanking of transmissions
may be attempted when a first call is a GSM call and is on hold.
More aggressive blanking may be implemented when, for example, the
sustainability of a 1xRTT, EV-DO, W-CDMA, LTE call is at risk.
[0098] When traffic calls for both the first and second
subscriptions 608a, 608b are connected on a GSM network, it may be
possible that both subscriptions 608a, 608b may be allocated the
same time slot. In some instances, the access terminal 602 that is
adapted or configured for eDSDS and/or sDSDA operation may drop the
call that has the lowest priority, in order to cause the lower
priority call to be reconnected with a new slot allocation.
[0099] FIG. 10 includes flowcharts illustrating methods of managing
multiple subscriptions in a wireless device. Certain steps of the
methods may be performed by an access terminal 502 of FIG. 5, the
access terminal 602 of FIG. 6 and/or elements or components of an
access terminal 502 or 602, such as the transceivers 702, 910 shown
in FIGS. 7 and 9, respectively.
[0100] The access terminal 602 may include a single RF transmit
chain 616c which may be timeshared in accordance with the method
illustrated by the "Transmit Chain" flowchart 1000, for example. At
step 1002, the access terminal 602 establishes a first call for a
first subscription associated with the access terminal 602.
[0101] At step 1004, the access terminal 602 accepts a second call
for a second subscription associated with the access terminal 602
while maintaining the first call in an active state. The first call
may be maintained in an active state that is an on-hold state. The
first subscription may correspond to an IMSI maintained on a first
SIM, and wherein the second subscription corresponds to an IMSI
maintained on a second SIM. Accepting the second call may include
increasing transmit power for the single RF transmit chain.
[0102] At step 1006, the access terminal 602 schedules the single
RF transmit chain 616c provided in the access terminal 602 for
uplink transmissions associated with the first call and uplink
transmissions associated with the second call when the access
terminal 602 is operating in a first mode. In one example, the
first mode may be a DSDA mode. Uplink transmissions may include
data traffic and/or control channel and signaling transmissions.
The single RF transmit chain 616c provided in the access terminal
602 may be scheduled to restrict uplink transmissions to a single
call when the access terminal 602 is operating in a second mode. In
one example, the second mode may be a DSDS mode. The access
terminal 602 may fall back to the second mode from the first mode
when one or more channel conditions are determined to be present.
The channel conditions may include high network loading, high
transmit power or adverse radio frequency (RF) coexistence
conditions. In one example, network loading can be expected to be
high when a large number of users are very active in the network.
In another example, transmit power may be considered high at 20 dBm
in a CDMA context, where 24 dBm is typically considered an upper
limit of transmit power. The thresholds at which network loading
and/or transmit power is considered to be high may vary according
to the network technology used, configuration and/or battery
capacity of an access terminal, RF coexistence protocols and other
factors.
[0103] In another aspect of the disclosure, scheduling the single
RF transmit chain 616c may include establishing a timesharing
schedule for the single RF transmit chain 616c. A switch provided
between a modem and the single RF transmit chain 616c may be
controlled in accordance with the timesharing schedule. The
timesharing schedule may determine timing of the uplink
transmissions associated with the first call and the uplink
transmissions associated with the second call on the single RF
transmit chain 616c. In one example, the timesharing schedule may
include decreasing a duration in which the power of one or more
neighboring transmitters is monitored in a GSM network.
[0104] In another aspect of the disclosure, scheduling the single
RF transmit chain or scheduling the single RF receive chain may
include dynamically adapting a frequency at which transmitter power
of a number of neighboring transmitters is monitored based on the
number of the neighboring sectors. Scheduling the single RF
transmit chain or scheduling the single RF receive chain may
include decreasing a power monitoring duration for a GSM network.
Scheduling the single RF transmit chain or scheduling the single RF
receive chain may include dropping one or more frames of a speech
packet to be transmitted on the uplink based on channel conditions.
In one example, 1 out of every 4 frames may be dropped or skipped.
Scheduling the single RF transmit chain or scheduling the single RF
receive chain may include skipping a portion of a plurality of
frames of a speech packet to be received on the downlink based on
channel conditions. Scheduling the single RF transmit chain or
scheduling the single RF receive chain may include skipping a
portion of a plurality of frames of a speech packet to be received
on the downlink when the speech packet is decoded using early
decoding. Scheduling the single RF transmit chain or scheduling the
single RF receive chain may include substituting silent frames for
at least a portion of a plurality of frames transmitted or received
on a GSM network.
[0105] In an aspect of the disclosure, maintaining the first call
in an active state may include dropping one or more frames of a
speech packet to be transmitted through the single RF transmit
chain 616c when the speech packet includes full-rate speech data
provided by an adaptive multi-rate audio codec. In one example, the
dropped frames may correspond to speech packets of the first call.
In another example, frames corresponding to speech packets of the
second call may be dropped while maintaining the second call.
[0106] In an aspect of the disclosure, the first call is
established as a highest priority call, and uplink transmissions
associated with the second call are gated when uplink transmissions
associated with the first call are required for transmission. The
uplink transmissions associated with the second call that are gated
may include an ACK channel transmission. All ACK channel
transmissions associated with the second call may be fully gated
when the uplink transmissions associated with the second call are
gated, including when network scheduling of the first call requires
the ACK channel transmission associated with the second call to be
partially gated.
[0107] In various aspects of the disclosure, the first call is
established on a GSM network and the second call is established on
a CDMA network, a UMTS network configured for W-CDMA or TD-SCDMA,
an LTE network (including LTE-FDD, LTE-TDD/TD-LTE networks), a
cdma2000 EV-DO network, a cdma2000 1xRTT network, or a TD-SCDMA
network. In another example, the first and second calls may be
established on two different GSM networks, or the same GSM network.
In yet another example, the first call may be established on an LTE
network configured for FDD or TDD network and the second call may
be established on a cdma2000 1xRTT network.
[0108] In an aspect of the disclosure, accepting the second call
includes boosting a traffic-to-pilot ratio or increasing overhead
channel gain.
[0109] An access terminal 602 may include a single RF receive chain
904 (see FIG. 9), or the access terminal may operate using one of a
plurality of available receive chains 616a or 616b. The single RF
receive chain 904, 616a or 616b may be timeshared in accordance
with the method illustrated by the "Receive Chain" flowchart 1020,
for example. At step 1022, the access terminal 602 may schedule a
single RF receive chain 904, 616a or 616b provided in the access
terminal 602 to receive downlink traffic associated with the first
call and downlink traffic associated with the second call.
[0110] At step 1024, the access terminal may establish a
timesharing schedule for the RF receive chain 904, 616a or 616b in
order to schedule the RF receive chain 904, 616a or 616b. A switch
provided between a modem and the RF receive chain 904, 616a or 616b
may be controlled in accordance with the timesharing schedule. The
timesharing schedule may determine when networks corresponding to
the first call and the second call are monitored. The RF receive
chain 904, 616a or 616b may be scheduled by decreasing a power
monitoring duration for a GSM network.
[0111] At step 1026, the access terminal 602 may configure the
timesharing schedule for the RF receive chain 904, 616a or 616b
based on channel conditions. In another aspect of the disclosure,
scheduling a RF receive chain 904, 616a or 616b may include
configuring a timesharing schedule corresponding to the RF receive
chain 904, 616a or 616b based on channel conditions. In one
example, the configuring the timesharing schedule may include
decreasing a duration in which the power of one or more neighboring
transmitters is monitored in a GSM network. In another example,
configuring the timesharing schedule may include dynamically
adapting a frequency at which the transmitter power of neighboring
sectors is monitored based on the number of neighboring sectors.
Configuring the timesharing schedule for the RF receive chain 904,
616a or 616b may include dropping one or more frames of a speech
packet to be transmitted on the uplink. Configuring the timesharing
schedule for the RF receive chain 904, 616a or 616b may include
causing one or more frames to be skipped based on channel
conditions when the speech packet includes full-rate speech data
produced by an adaptive multi-rate audio codec. Frames may be
skipped when the speech packet is decoded using early decoding.
Configuring the timesharing schedule for the single RF receive
chain may include substituting silent frames for all or a portion
of frames transmitted or received on a GSM network.
[0112] In an aspect of the disclosure, the method includes
compensating for phase discontinuities in a pilot signal detected
on a network corresponding to one of the first call and the second
call.
[0113] In an aspect of the disclosure, the method includes reducing
a frequency at which neighboring transmitter power is
monitored.
[0114] In an aspect of the disclosure, the first call and the
second call are GSM calls, and the first call has a higher priority
than the second call and the second call may be dropped when the
first call and the second call are allocated a common time slot for
communicating on a GSM network.
[0115] FIG. 11 is a diagram 1100 illustrating an example of a
hardware implementation for an access terminal 1102 configured to
manage multiple connections for a wireless device. The access
terminal 1102 may include an access terminal having a processing
circuit 1104. The processing circuit 1104 may be implemented with a
bus architecture, represented generally by the bus 1130. The bus
1130 may include any number of interconnecting buses and bridges
depending on the application and attributes of the processing
circuit 1104 and overall design constraints. The bus 1130 may link
together various circuits including one or more processors and/or
hardware modules, processing circuit 1104, and the
processor-readable medium 1106. The bus 1130 may also link various
other circuits such as timing sources, peripherals, voltage
regulators, and power management circuits, which are well known in
the art, and therefore, will not be described any further.
[0116] The processing circuit 1104 may be coupled to one or more
communications interfaces or transceivers 1114. The one or more
communications interfaces 1108, 1110 may be used for communications
with entities of a core network, and includes one or more of a Tx
chains 1110 and one or more Rx chains 1108. The one or more Tx
chains 1110 and the one or more Rx chains 1108 may be coupled to
one or more internal and/or external antennas 1116.
[0117] The processing circuit 1104 may include one or more
processors responsible for general processing, including the
execution of software stored on the processor-readable medium 1106.
For example, the processing circuit 1104 may include one or more
processors deployed in the access terminals 302, 402, 502, 602 of
FIGS. 3-6 and/or the transceivers 702, 910 of FIGS. 7 and 9. The
software, when executed by the one or more processors, cause the
processing circuit 1104 to perform the various functions described
supra for any particular access terminal The processor-readable
medium 1106 may also be used for storing data that is manipulated
by the processing circuit 1104 when executing software. The
processing system further includes at least one of the modules
1120, 1122, 1124 and 1126. The modules 1120, 1122, 1124 and 1126
may be software modules running on the processing circuit 1104,
resident/stored in the processor-readable medium 1106, one or more
hardware modules coupled to the processing circuit 1104, or some
combination thereof.
[0118] In one configuration, the access terminal 1102 for wireless
communication includes a module or circuit 1120 configured to
establish a first call for a first subscription associated with the
access terminal 1102, modules or circuits 1122, 1126 configured to
accept a second call for a second subscription associated with the
access terminal 1102 while maintaining the first call, and a module
or circuit 1124 configured to schedule a single RF transmit chain
provided in the access terminal for uplink transmissions associated
with the first call and uplink transmissions associated with the
second call when the access terminal is operating in a DSDA mode.
The module or circuit 1124 may cooperate with the Tx chain 1110 of
the transceiver 1114. The module or circuit 1124 may be further
configured to facilitate receipt of downlink traffic associated
with the first call and downlink traffic associated with the second
call using a one or more receive chains 1108 provided in the access
terminal 1102. One or more Rx chains 1108 may be used to receive
downlink communications. The module or circuit 1124 may manage
timesharing of an Rx chain 1108 and/or a Tx chain 1110. The call
maintenance module or circuit 1126 may maintain the first and
second calls. In one example, the call maintenance module or
circuit 1126 may include components for dropping the second call
when the first call and the second call are allocated a common time
slot for communicating on a GSM network, and components that
compensate for phase discontinuities in a pilot signal detected on
a network corresponding to one of the first call and the second
call.
[0119] The term "aspects" does not require that all aspects of the
disclosure include the discussed feature, advantage or mode of
operation. The term "coupled" is used herein to refer to the direct
or indirect coupling between two objects. For example, if object A
physically touches object B, and object B touches object C, then
objects A and C may still be considered coupled to one another,
even if they do not directly physically touch each other. For
instance, a first die may be coupled to a second die in a package
even though the first die is never directly physically in contact
with the second die.
[0120] One or more of the components, steps, features and/or
functions illustrated in FIGS. 1-11 may be rearranged and/or
combined into a single component, step, feature or function or
embodied in several components, steps, or functions. Additional
elements, components, steps, and/or functions may also be added
without departing from novel features disclosed herein. The
apparatus, devices, and/or components illustrated in FIGS. 1-7, 9
and 11 may be configured to perform one or more of the methods,
features, or steps described herein. The novel algorithms described
herein may also be efficiently implemented in software and/or
embedded in hardware.
[0121] Also, it is noted that the embodiments may be described as a
process that is depicted as a flowchart, a flow diagram, a
structure diagram, or a block diagram. Although a flowchart may
describe the operations as a sequential process, many of the
operations can be performed in parallel or concurrently. In
addition, the order of the operations may be re-arranged. A process
is terminated when its operations are completed. A process may
correspond to a method, a function, a procedure, a subroutine, a
subprogram, etc. When a process corresponds to a function, its
termination corresponds to a return of the function to the calling
function or the main function.
[0122] Moreover, a storage medium may represent one or more devices
for storing data, including read-only memory (ROM), random access
memory (RAM), magnetic disk storage mediums, optical storage
mediums, flash memory devices and/or other machine readable mediums
for storing information. The terms "machine readable medium" or
"machine readable storage medium" include, but is not limited to
portable or fixed storage devices, optical storage devices,
wireless channels and various other mediums capable of storing,
containing or carrying instruction(s) and/or data.
[0123] Furthermore, embodiments may be implemented by hardware,
software, firmware, middleware, microcode, or any combination
thereof When implemented in software, firmware, middleware or
microcode, the program code or code segments to perform the
necessary tasks may be stored in a machine-readable medium such as
a storage medium or other storage(s). A processor may perform the
necessary tasks. A code segment may represent a procedure, a
function, a subprogram, a program, a routine, a subroutine, a
module, a software package, a class, or any combination of
instructions, data structures, or program statements. A code
segment may be coupled to another code segment or a hardware
circuit by passing and/or receiving information, data, arguments,
parameters, or memory contents. Information, arguments, parameters,
data, etc. may be passed, forwarded, or transmitted via any
suitable means including memory sharing, message passing, token
passing, network transmission, etc.
[0124] The various illustrative logical blocks, modules, circuits
(e.g., processing circuit), elements, and/or components described
in connection with the examples disclosed herein may be implemented
or performed with a general purpose processor, a digital signal
processor (DSP), an application specific integrated circuit (ASIC),
a field programmable gate array (FPGA) or other programmable logic
component, discrete gate or transistor logic, discrete hardware
components, or any combination thereof designed to perform the
functions described herein. A general purpose processor may be a
microprocessor, but in the alternative, the processor may be any
conventional processor, controller, microcontroller, or state
machine. A processor may also be implemented as a combination of
computing components, e.g., a combination of a DSP and a
microprocessor, a number of microprocessors, one or more
microprocessors in conjunction with a DSP core, or any other such
configuration.
[0125] The methods or algorithms described in connection with the
examples disclosed herein may be embodied directly in hardware, in
a software module executable by a processor, or in a combination of
both, in the form of processing unit, programming instructions, or
other directions, and may be contained in a single device or
distributed across multiple devices. A software module may reside
in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM
memory, registers, hard disk, a removable disk, a CD-ROM, or any
other form of storage medium known in the art. A storage medium may
be coupled to the processor such that the processor can read
information from, and write information to, the storage medium. In
the alternative, the storage medium may be integral to the
processor.
[0126] Those of skill in the art would further appreciate that the
various illustrative logical blocks, modules, circuits, and
algorithm steps described in connection with the embodiments
disclosed herein may be implemented as electronic hardware,
computer software, or combinations of both. To clearly illustrate
this interchangeability of hardware and software, various
illustrative components, blocks, modules, circuits, and steps have
been described above generally in terms of their functionality.
Whether such functionality is implemented as hardware or software
depends upon the particular application and design constraints
imposed on the overall system.
[0127] The various features of the invention described herein can
be implemented in different systems without departing from the
invention. It should be noted that the foregoing aspects of the
disclosure are merely examples and are not to be construed as
limiting the invention. The description of the aspects of the
present disclosure is intended to be illustrative, and not to limit
the scope of the claims. As such, the present teachings can be
readily applied to other types of apparatuses and many
alternatives, modifications, and variations will be apparent to
those skilled in the art.
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