U.S. patent application number 13/024124 was filed with the patent office on 2011-08-25 for method and system for a time domain approach to 4g wimax/lte-wifi/bt coexistence.
Invention is credited to Kameswara Rao Medapalli.
Application Number | 20110205986 13/024124 |
Document ID | / |
Family ID | 44476426 |
Filed Date | 2011-08-25 |
United States Patent
Application |
20110205986 |
Kind Code |
A1 |
Medapalli; Kameswara Rao |
August 25, 2011 |
Method and System for a Time Domain Approach to 4G
WiMAX/LTE-WiFi/BT Coexistence
Abstract
A method and system are provided in which a device that is
operable to handle WiFi communication and WiMAX communication may
receive downlink medium access protocol (MAP) information in a
downlink sub-frame of a WiMAX frame and disable WiFi transmission
during a portion of the downlink sub-frame based on the downlink
MAP information. The disabled WiFi transmission may be enabled
after data within the downlink sub-frame is decoded. The device may
also receive uplink MAP information in the downlink sub-frame and
may control a clear channel assessment associated with the WiFi
transmission based on the uplink MAP information. The MAP
information may comprise data or burst profile information and/or
one or more physical control messages. A similar time domain
approach may be utilized for coexistence between WiFi and long term
evolution (LTE) coexistence, Bluetooth and WiMAX, and Bluetooth and
LTE. Frame aggregation may be enabled to alleviate pending WiFi
traffic.
Inventors: |
Medapalli; Kameswara Rao;
(San Jose, CA) |
Family ID: |
44476426 |
Appl. No.: |
13/024124 |
Filed: |
February 9, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61308250 |
Feb 25, 2010 |
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04L 5/0092 20130101;
H04L 5/0062 20130101; H04W 72/1215 20130101; H04W 72/0446
20130101 |
Class at
Publication: |
370/329 |
International
Class: |
H04W 72/04 20090101
H04W072/04 |
Claims
1. A method, comprising: in a device operable to handle WiFi
communication and WiMAX communication: receiving downlink medium
access protocol (MAP) information in a downlink sub-frame of a
WiMAX frame; and disabling WiFi transmission during a portion of
the downlink sub-frame based on the received downlink MAP
information.
2. The method of claim 1, wherein the downlink MAP information
comprises a downlink burst profile and one or more physical layer
control messages.
3. The method of claim 1, comprising: decoding data within the
downlink sub-frame; and enabling the disabled WiFi transmission
after the data is decoded.
4. The method of claim 1, comprising: receiving uplink MAP
information in the downlink sub-frame of the WiMAX frame;
generating a signal during an uplink sub-frame of the WiMAX frame
based on the received uplink MAP information; and controlling a
clear channel assessment operation associated with the WiFi
transmission based on the generated signal.
5. The method of claim 4, wherein the uplink MAP information
comprises an uplink burst profile and one or more physical layer
control messages.
6. The method of claim 1, comprising: generating an indication of
pending WiFi transmission traffic; requesting bandwidth allocation
modification to a base station based on the generated indication;
and when an indication is received that the request is granted,
aggregating WiMAX transmission traffic in accordance with a
schedule associated with the granted request.
7. The method of claim 1, wherein WiMAX downlink traffic is
correlated to WiFi downlink traffic.
8. The method of claim 1, wherein WiMAX uplink traffic is
correlated to WiFi uplink traffic.
9. The method of claim 1, comprising: receiving downlink MAP
information in a downlink sub-frame of a next WiMAX frame; and
disabling WiFi transmission during a portion of the downlink
sub-frame of the next WiMAX frame based on the received downlink
MAP information in the downlink sub-frame of the next WiMAX
frame.
10. The method of claim 1, wherein the disabling of the WiFi
transmission comprises disabling a baseband operation associated
with the WiFi transmission and a radio frequency front end power
amplifier associated with the WiFi transmission.
11. A system, comprising: one or more processors and/or circuits
for use in a device that handles WiFi communication and WiMAX
communication, the one or more processors and/or circuits being
operable to: receive downlink medium access protocol (MAP)
information in a downlink sub-frame of a WiMAX frame; and disable
WiFi transmission during a portion of the downlink sub-frame based
on the received downlink MAP information.
12. The system of claim 11, wherein the downlink MAP information
comprises a downlink burst profile and one or more physical layer
control messages.
13. The system of claim 11, wherein the one or more processors
and/or circuits are operable to: decode data within the downlink
sub-frame; and enable the disabled WiFi transmission after the data
is decoded.
14. The system of claim 11, wherein the one or more processors
and/or circuits are operable to: receive uplink MAP information in
the downlink sub-frame of the WiMAX frame; generate a signal during
an uplink sub-frame of the WiMAX frame based on the received uplink
MAP information; and control a clear channel assessment operation
associated with the WiFi transmission based on the generated
signal.
15. The system of claim 14, wherein the uplink MAP information
comprises an uplink burst profile and one or more physical layer
control messages.
16. The system of claim 11, wherein the one or more processors
and/or circuits are operable to: generate an indication of pending
WiFi transmission traffic; request bandwidth allocation
modification to a base station based on the generated indication;
and when an indication is received that the request is granted,
aggregate WiMAX transmission traffic in accordance with a schedule
associated with the granted request.
17. The system of claim 11, wherein WiMAX traffic is correlated to
WiFi traffic.
18. The system of claim 11, wherein the one or more processors
and/or circuits are operable to: receive downlink MAP information
in a downlink sub-frame of a next WiMAX frame; and disable WiFi
transmission during a portion of the downlink sub-frame of the next
WiMAX frame based on the received downlink MAP information in the
downlink sub-frame of the next WiMAX frame.
19. The system of claim 11, wherein the one or more processors
and/or circuits are operable to: disable a baseband operation
associated with the WiFi transmission and a radio frequency front
end power amplifier associated with the WiFi transmission.
20. The system of claim 11, wherein the one or more processors
and/or circuits are disposed in a single package on a single
substrate.
21. A method, comprising: in a device operable to handle a first
communication type and a second communication type, wherein the
first communication type is one of WiFi, Bluetooth, and Zigbee and
the second communication type is one of WiMAX and LTE: receiving
downlink medium access protocol (MAP) information in a downlink
sub-frame of a frame associated with the second communication type;
and disabling transmission of the first communication type during a
portion of the downlink sub-frame based on the received downlink
MAP information.
22. A system, comprising: one or more processors and/or circuits
for use in a device that handles a first communication type and a
second communication type, wherein the first communication type is
one of WiFi, Bluetooth, and Zigbee and the second communication
type is one of WiMAX and LTE, the one or more processors and/or
circuits being operable to: receive downlink medium access protocol
(MAP) information in a downlink sub-frame of a frame associated
with the second communication type; and disable transmission of the
first communication type during a portion of the downlink sub-frame
based on the received downlink MAP information.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY
REFERENCE
[0001] This application claims priority to and makes reference to
U.S. Provisional Patent Application Ser. No. 61/308,250 filed on
Feb. 25, 2010.
[0002] The above stated application is hereby incorporated herein
by reference in its entirety.
FIELD OF THE INVENTION
[0003] Certain embodiments of the invention relate to interference
in communication systems. More specifically, certain embodiments of
the invention relate to a method and system for a time domain
approach to 4G WiMAX/LTE and WiFi/BT coexistence.
BACKGROUND OF THE INVENTION
[0004] Personal area networks (PANs), such as WiFi networks and
Bluetooth (BT) networks, for example, and fourth generation (4G)
networks, such as Worldwide Interoperability for Microwave Access
(WiMAX) and Long Term Evolution (LTE), for example, have been
gaining popularity because of the flexibility, convenience in
connectivity, and/or high data throughput they provide. Devices
that support both types of networks need to enable operation with
limited and/or reduced interference.
[0005] Further limitations and disadvantages of conventional and
traditional approaches will become apparent to one of skill in the
art, through comparison of such systems with the present invention
as set forth in the remainder of the present application with
reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0006] A system and/or method for a time domain approach to 4G
WiMAX/LTE and WiFi/BT coexistence, as set forth more completely in
the claims.
[0007] Various advantages, aspects and novel features of the
present invention, as well as details of an illustrated embodiment
thereof, will be more fully understood from the following
description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0008] FIG. 1A is a diagram that illustrates an exemplary router
that supports communication through a 4G network and a WiFi
network, in accordance with an embodiment of the invention.
[0009] FIG. 1B is a diagram that illustrates an exemplary device
that supports communication through a 4G network and a PAN network,
in accordance with an embodiment of the invention.
[0010] FIG. 2 is a diagram that illustrates WiMAX and WiFi/BT radio
spectrum, in connection with an embodiment of the invention.
[0011] FIGS. 3A-3B are block diagrams of exemplary 4G and WiFi/BT
coexistence systems, in accordance with embodiments of the
invention.
[0012] FIG. 4 is a diagram that illustrates an exemplary time
domain approach to 4G and WiFi/BT coexistence, in accordance with
an embodiment of the invention.
[0013] FIG. 5 is a flow diagram that illustrates exemplary steps
for a time domain approach to 4G and WiFi/BT coexistence, in
accordance with an embodiment of the invention.
[0014] FIG. 6 is a flow diagram that illustrates exemplary steps to
aggregate uplink transmissions in a 4G and WiFi/BT coexistence
system, in accordance with an embodiment of the invention.
[0015] FIG. 7 is a flow diagram that illustrates exemplary steps
during WiMAX handoff scanning in a 4G and WiFi/BT coexistence
system, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Certain embodiments of the invention can be found in a
method and system for a time domain approach to 4G WiMAX/LTE and
WiFi/BT coexistence. Various embodiments of the invention provide a
device that is operable to handle WiFi communication and WiMAX
communication. Such device may receive downlink medium access
protocol (MAP) information in a downlink sub-frame of a WiMAX frame
and may disable WiFi transmission during a portion of the downlink
sub-frame based on the received downlink MAP information. The
disabled WiFi transmission may be enabled after data within the
downlink sub-frame is decoded. The device may also receive uplink
MAP information in the downlink sub-frame and may control a clear
channel assessment (CCA) associated with the WiFi transmission
based on the received uplink MAP information. The MAP information
in the downlink sub-frame may comprise a profile of the data or
burst information and/or one or more physical control messages
associated with both sub-frames in the WiMAX frame. In an LTE
system, the Packet Data Control Channel (PDCCH) and the Physical
Uplink Control Channel (PUCCH) may be utilized to inform the
terminal about downlink and uplink transmissions. A similar time
domain approach may be utilized for WiFi and time-division duplex
LTE (TDD-LTE) coexistence. In case of frequency-division duplex LTE
(FDD-LTE), the approach is applicable to WiFi/BT coexistence with
certain extensions as described below. Moreover, frame aggregation
may be enabled to alleviate pending WiFi transmission traffic.
[0017] FIG. 1A is a diagram that illustrates an exemplary router
that supports communication through a 4G network and a WiFi
network, in accordance with an embodiment of the invention.
Referring to FIG. 1A, there is shown a 4G network 130 and a WiFi
network 140. In some embodiments of the invention, the 4G network
130 may be a WiMAX network such as a mobile WiMAX network or a
WirelessMAN-Advanced network, for example. In other embodiments of
the invention, the 4G network 130 may be an LTE network, including
advanced versions of LTE such as an LTE Advanced network, for
example. The LTE network may operate as a TDD-LTE network or as an
FDD-LTE network. In yet another embodiment of the invention, the 4G
network 130 may support WiMAX communication and LTE communication
at the same time.
[0018] A base station 110 and a router 100 are also shown as part
of the 4G network 130. The base station 110 and the router 100 may
communicate through a link 132 that enables 4 G communication in a
downlink direction and/or in an uplink direction. The router 100
and a user device 120 are shown as part of the WiFi network 140.
The router 100 and the user device 120 may communicate through a
link 142 that enables WiFi communication in a downlink direction
and/or in an uplink direction.
[0019] The router 100 may be a mobile router, for example. The
router 100 may comprise suitable logic, circuitry, interfaces
and/or code that may be operable to limit and/or reduce the
interference that may occur by having 4G and WiFi coexistent
operations. The router 100 may be operable to communicate such that
the reception of WiMAX or LTE signals from the base station 110 is
not affected by the transmission of WiFi signals to the user device
120. In this regard, the router 100 may enable about a 25 dB
isolation between the antenna(s) used for 4 G communication and the
antenna(s) used for WiFi communication. The router 100 may support
other types of communication as well. For example, the router 100
may support communication through wireless local area networks that
are based on the IEEE 802.11 standards, through other cellular
wireless networks, and/or through personal area network
technologies.
[0020] The user device 120 may comprise suitable logic, circuitry,
interfaces and/or code that may be operable to support WiFi
communication. Moreover, the user device 120 may support
communication with one or more nearby devices (not shown) through
personal area network technologies such as infrared data
association (IrDA), Bluetooth, ultra-wideband (UWB), Z-Wave and
ZigBee, for example. The user device 120 may be, for example, a
smartphone, a laptop, a tablet, or other like mobile and/or
portable computing device. The user device 120 may also be referred
to as a station.
[0021] In operation, downlink traffic may flow from the base
station 110 to the router 100 via the link 132 in the 4G network
130. The downlink traffic may then be communicated by the router
100 to the user device 120 via the link 142 in the WiFi network
140. In such an instance, since similar downlink traffic may flow
in both networks, the downlink traffic in the 4G network 130 may be
said to be correlated with the downlink traffic in the WiFi network
140.
[0022] Similarly, uplink traffic may flow from the user device 120
to the router 100 via the link 142 in the WiFi network 140. The
uplink traffic may then be communicated by the router 100 to the
base station 110 via the link 132 in the 4G network 130. In such an
instance, since similar uplink traffic may flow in both networks,
the uplink traffic in the WiFi network 140 may be said to be
correlated with the uplink traffic in the 4G network 130.
[0023] In one embodiment of the invention, when the 4G network 130
is a WiMAX network and a single station is considered in the WiFi
network 140, the WiMAX/WiFi downlink throughput may be able to
support about 13 megabits-per-second (Mb/s) for Transmission
Control Protocol (TCP) while the WiMAX/WiFi uplink throughput may
be able to support about 4 Mb/s for TCP.
[0024] In another embodiment of the invention, when the 4G network
130 is an LTE network and a single station is considered in the
WiFi network 140, the LTE/WiFi downlink throughput may be able to
support about 50 Mb/s for TCP while the LTE/WiFi uplink throughput
may be able to support about 10 Mb/s for TCP.
[0025] FIG. 1B is a diagram that illustrates an exemplary device
that supports communication through a 4G network and a PAN network,
in accordance with an embodiment of the invention. Referring to
FIG. 1B, there is shown the 4G network 130, the base station 110,
the user device 120, a personal area network 150, and a coexistence
device 160. The personal area network 150 may support one or more
of IrDA, Bluetooth, UWB, Z-Wave, and ZigBee technologies, which may
also be supported by the user device 120.
[0026] The coexistence device 160 may comprise suitable logic,
circuitry, code, and/or interfaces that may be operable to enable
traffic between the 4G network 130 and the personal area network
150. In this regard, the coexistence device 160 may be operable to
limit and/or reduce the interference that may occur by having 4G
and personal area network technologies coexist. In some embodiments
of the invention, the coexistence device 160 may be a router such
as the router 100 described above. In other embodiments of the
invention, the coexistence device 160 may be a mobile computing
device, such as a smartphone, for example.
[0027] The coexistence device 160 may communicate with the base
station 110 through a link 152 that may be substantially similar to
the link 132 described above. The coexistence device 160 and the
user device 120 may communicate through a link 154 that enables
IrDA, Bluetooth, UWB, Z-Wave, and/or ZigBee communication in a
downlink direction and/or in an uplink direction. In some
instances, the user device 120 may refer to a peripheral device
such as a headset and/or printer, for example.
[0028] When the personal area network 150 supports Bluetooth and/or
ZigBee communication, for example, the traffic in the personal area
network 150 and the traffic in the 4G network 130 may be
correlated.
[0029] FIG. 2 is a diagram that illustrates WiMAX and WiFi/BT radio
spectrum, in connection with an embodiment of the invention.
Referring to FIG. 2, there is shown a portion of the radio spectrum
200 that may be utilized for an unlicensed Industrial, Scientific,
and Medical (ISM) band. The unlicensed ISM band is positioned
between portions of the radio spectrum 210 and 212 that may be
utilized for WiMAX communication. For example, the unlicensed ISM
band may comprise those frequencies between 2.401 GHz and 2.473
GHz, while frequencies above 2.496 GHz and below 2.36 GHz may be
utilized for WiMAX communication. In some instances, the same
portion of the radio spectrum utilized for WiMAX communication may
support LTE communication.
[0030] The frequencies in the unlicensed ISM band may be utilized
for WiFi and/or Bluetooth communication. For WiFi applications in
North America, 11 different channels 220, each having a 22 MHz
bandwidth, may be utilized as shown in FIG. 2. Bluetooth comprises
79 channels in the ISM band, each channel having a 1 MHz bandwidth.
Bluetooth channel hopping operates at a rate of 1600 times per
second.
[0031] The close frequency separation that exists between the WiMAX
radio spectrum and the unlicensed ISM band may result in mutual
interference among wireless technologies that utilize such close
frequencies. Accordingly, a router, such as the router 100
described above with respect to FIG. 1A, may need to enable
operations that limit and/or reduce interference.
[0032] In accordance with an embodiment of the invention, the
router 100 may perform a time domain approach to 4G and WiFi
coexistence to limit and/or reduce interference by enabling and/or
disabling WiFi communication based on information received through
one or more WiMAX and/or LTE frames. Similarly, the coexistence
device 160 may perform a time domain approach to 4G and Bluetooth
coexistence to limit and/or reduce interference by enabling and/or
disabling Bluetooth communication based on information received
through one or more WiMAX and/or LTE frames.
[0033] FIGS. 3A-3B are block diagrams of exemplary 4G and WiFi/BT
coexistence systems, in accordance with embodiments of the
invention. Referring to FIG. 3A, there is shown a 4G and WiFi/BT
coexistence system 300 that may comprise a WiFi/BT modem 310, a 4G
modem 320, a WiFi/BT front end 330, and a 4G front end 340. In some
embodiments of the invention, the various components shown in FIG.
3A may be implemented in the router 100, in the coexistence device
160, or in other like device.
[0034] The WiFi/BT modem 310 may comprise suitable logic,
circuitry, code, and/or interfaces that may operable to handle WiFi
and/or Bluetooth communication. In this regard, the WiFi/BT modem
310 may be operable to process data, control signals, and/or other
information associated with WiFi and/or Bluetooth communication. In
some embodiments of the invention, the WiFi/BT modem 310 may be
operable to perform routing operations. The WiFi/BT modem 310 may
be implemented as an integrated circuit having a single substrate
and disposed in a single package. In some embodiments of the
invention, the WiFi/BT modem 310 may support only one of WiFi
communication and Bluetooth communication. In other embodiments of
the invention, the WiFi/BT modem 310 may support both of WiFi
communication and Bluetooth communication.
[0035] The WiFi/BT modem 310 may be operable to receive uplink
traffic from a user device, such as the user device 120, for
example. The uplink traffic may be received by the WiFi/BT modem
310 through the WiFi/BT front end 330 and signals 322. The WiFi/BT
modem 310 may communicate the uplink traffic to the 4G modem 320
when such traffic is intended to be communicated to the base
station 110. The transfer of the uplink traffic between the two
modems may occur via one or more buses (not shown) that may be
controlled by one or more processors (not shown) using information
such as queue depths, delay, and/or throughput.
[0036] The WiFi/BT modem 310 may be operable to receive downlink
traffic from the 4G modem 320. Such downlink traffic may have been
received by the 4G modem 320 from the base station 110, for
example, and may be intended for the user device 120. The transfer
of the downlink traffic between the two modems may occur via one or
more buses (not shown) that may be controlled by one or more
processors (not shown) using information such as queue depths,
delay, and/or throughput. The downlink traffic may be communicated
to the user device 120 through the WiFi/BT front end 330 and
signals 322.
[0037] The 4G modem 320 may comprise suitable logic, circuitry,
code, and/or interfaces that may operable to handle 4 G
communication such as WiMAX communication and/or LTE communication,
for example. In this regard, the 4G modem 320 may be operable to
process data, control signals, and/or other information associated
with WiMAX communication and/or LTE communication. In some
embodiments of the invention, the 4G modem 320 may be operable to
perform routing operations. The 4G modem 320 may be implemented as
an integrated circuit having a single substrate and disposed in a
single package.
[0038] The 4G modem 320 may be operable to receive downlink traffic
from a base station, such as the base station 110, for example. The
downlink traffic may be received by the 4G modem 320 through the 4G
front end 340 and signals 332. The 4G modem 320 may communicate the
downlink traffic to the WiFi/BT modem 310 when such traffic is
intended to be communicated to the user device 120. The transfer of
the downlink traffic between the two modems may occur via one or
more buses (not shown) that may be controlled by one or more
processors (not shown) using information such as queue depths,
delay, and/or throughput.
[0039] The 4G modem 320 may be operable to receive uplink traffic
from the WiFi/BT modem 310. Such uplink traffic may have been
received by the WiFi/BT modem 310 from the user device 120, for
example, and may be intended for the base station 110. The transfer
of the uplink traffic between the two modems may occur via one or
more buses (not shown) that may be controlled by one or more
processors (not shown) using information such as queue depths,
delay, and/or throughput. The uplink traffic may be communicated to
the base station 110 through the 4G front end 340 and signals
332.
[0040] The WiFi/BT front end 330 may comprise suitable logic,
circuitry, code, and/or interfaces that may be operable to transmit
and/or receive WiFi and/or Bluetooth signals over the unlicensed
ISM band. The WiFi/BT front end 330 may be operable to perform
various operations on WiFi and/or Bluetooth signals such as
filtering, amplifying, mixing, upconverting, and/or downconverting,
for example.
[0041] The 4G front end 340 may comprise suitable logic, circuitry,
code, and/or interfaces that may be operable to transmit and/or
receive 4G signals in portions of the radio spectrum that are near
the unlicensed ISM band. The 4G front end 340 may be operable to
perform various operations on 4G signals such as filtering,
amplifying, mixing, upconverting, and/or downconverting, for
example. The 4G front end 340 may be operable to perform
multiple-input-multiple-output (MIMO) operations associated with
the transmission and/or reception of 4G signals. In this regard,
the 4G front end 340 may utilize multiple antennas for carrying out
the MIMO operations.
[0042] In operation, the 4G and WiFi/BT coexistence system 300 may
utilize a time domain approach to limit and/or reduce interference
in 4G and WiFi coexistence by enabling and/or disabling WiFi
communication based on information received through one or more
WiMAX and/or LTE frames. Similarly, the 4G and WiFi/BT coexistence
system 300 may utilize a time domain approach to limit and/or
reduce interference in 4G and Bluetooth coexistence by enabling
and/or disabling Bluetooth communication based on information
received through one or more WiMAX and/or LTE frames.
[0043] FIG. 3A also shows a high-level discrete signaling mechanism
between the 4G modem 320 and the WiFi/BT modem 310 that may be
utilized to limit and/or reduce interference in the 4G and WiFi/BT
coexistence system 300. The signaling mechanism shown in FIG. 3A is
based on a 3-wire interface, however, fewer or more wires and/or
signals may also be utilized to implement the signaling
mechanism.
[0044] A signal 334, RX_Active, may be asserted by the 4G modem 320
and the asserted signal may be communicated to the WiFi/BT modem
310 to indicate that the 4G modem 320 is receiving information and
that the WiFi/BT modem 310 is to stop or terminate any WiFi and/or
Bluetooth transmissions and/or related baseband processing. The
asserted RX_Active signal 334 may also be communicated to the
WiFi/BT front end 330 to disable a power amplifier (PA) 350. By
disabling both the baseband processing and the PA 350 through the
asserted RX_Active signal 334, the 4G modem 320 may receive 4G
signals without the likelihood of interference from WiFi and/or BT
transmissions. Additional information regarding the RX_Active
signal 334 is provided below with respect to FIG. 4.
[0045] A signal 336, TX_Active, may be asserted by the 4G modem 320
and the asserted signal may be communicated to the WiFi/BT modem
310 to indicate that the 4G modem 320 is transmitting information
and that the WiFi/BT modem 310 may transmit or receive WiFi and/or
Bluetooth signals. The TX_Active signal 336 may be utilized by the
WiFi/BT modem 310 in connection with a CCA operation in WiFi to
determine that the energy that is being detected by the WiFi/BT
modem 310 in the physical medium is associated with the 4G
transmission and not with some other source. By having knowledge
that the energy being detected is from the 4G modem 320, the
WiFi/BT modem 310 need not limit its operation when such energy is
detected. Additional information regarding the TX_Active signal 336
is provided below with respect to FIG. 4.
[0046] A signal 338, WiFi_Data_Pending, may be asserted by the
WiFi/BT modem 310 and the asserted signal may be communicated to
the 4G modem 320 to indicate that there is a backup in WiFi and/or
Bluetooth transmissions. The 4G modem 320 may utilize this
information to modify the bandwidth allocated by the base station
to alleviate the pending WiFi transmissions in the WiFi/BT modem
310. Additional information regarding the WiFi_Data_Pending signal
338 is provided below with respect to FIG. 6.
[0047] Referring to FIG. 3B, there is shown a 4G and WiFi/BT
coexistence system 350 that may comprise a 4G-WiFi/BT modem 360,
the WiFi/BT front end 330, and the 4G front end 340. In some
embodiments of the invention, the various components shown in FIG.
3B may be implemented in the router 100, in the coexistence device
160, or other like device.
[0048] The 4G-WiFi/BT modem 360 may be operable to perform the
operations of the WiFi/BT modem 310 and of the 4G modem 320
described above. In addition, the functionality and/or operation
associated with high-level discrete signaling mechanism described
above may be implemented within the 4G-WiFi/BT modem 360. In this
regard, transmit and/or receive buffer information may be utilized
by the 4G-WiFi/BT modem 360 to generate the appropriate signaling
and/or equivalent functionality to limit interference between 4G
and WiFi communications and/or between 4G and Bluetooth
communications. Part of the signaling operation may comprise
generating a signal 354 to disable the PA 350 in the WiFi/BT front
end 330 when appropriate. The 4G-WiFi/BT modem 360 may be
implemented as an integrated circuit having a single substrate and
disposed in a single package. In some embodiments of the invention,
the 4G-WiFi/BT modem 360 may support only one of WiFi communication
and Bluetooth communication. In other embodiments of the invention,
the 4G-WiFi/BT modem 360 may support both of WiFi communication and
Bluetooth communication.
[0049] Referring to FIG. 3C, there is shown a 4G and WiFi/BT
coexistence system 370 that may comprise the 4G-WiFi/BT modem 360,
the WiFi/BT front end 330, and the 4G front end 340. In some
embodiments of the invention, the 4G and WiFi/BT coexistence system
370 shown in FIG. 3C may be implemented in the router 100, in the
coexistence device 160, or other like device. The 4G and WiFi/BT
coexistence system 370 may be implemented as an integrated circuit
having a single substrate and disposed in a single package.
[0050] FIG. 4 is a diagram that illustrates an exemplary time
domain approach to 4G and WiFi/BT coexistence, in accordance with
an embodiment of the invention. Referring to FIG. 4, there are
shown two consecutive WiMAX frames, Frame N and Frame N+1, which
may be associated with WiMAX communication in a system such as the
4G and WiFi/BT coexistence system 300, for example.
[0051] The first frame, Frame N, may comprise a downlink (DL)
sub-frame and an uplink (UL) sub-frame. The second frame, Frame
N+1, may also comprise a DL sub-frame and a UL sub-frame. The DL
sub-frames in both frames may have a substantially similar
structure. The UL sub-frames in both frames may also have a
substantially similar structure. For example, both DL sub-frames
may comprise 29 symbols and have a duration of about 3 milliseconds
(ms). The DL sub-frames may comprise a preamble 408, downlink and
uplink (DL/UL) medium access protocol (MAP) information 410, and DL
data protocol data units (PDUs) 412. The DL data PDUs 412 may be
structured to support multiple downlink data bursts. The MAP
information may comprise a downlink burst profile, an uplink burst
profile, and one or more physical layer control messages.
[0052] Both UL sub-frames may comprise 18 symbols and may have a
duration of about 2 ms. The UL sub-frames may comprise ranging
information 422, Channel Quality Indicator Channel (CQICH)
information 424, Hybrid Automatic Repeat Request (HARQ) information
426, and an UL data zone 420. The UL data zone 420 may be
structured to support multiple uplink data bursts.
[0053] In operation, the 4G modem 320 in the 4G and WiFi/BT
coexistence system 300 may begin processing the DL sub-frame of
Frame N. In this regard, the RX_Active signal 334 may be asserted
by the 4G modem 320 at the start of the DL sub-frame processing,
that is, at time instant TO. The 4G modem 320 may determine, based
on the downlink MAP information in the DL/UL MAP information 410,
whether there is any data that needs to be decoded in the DL data
PDUs 412. In this example, data is available to be decoded and the
4G modem 320 maintains the RX_Active signal 334 asserted until the
decoding is completed at time instant T1. While the DL sub-frame of
Frame N ends at time instant T2, the RX_Active signal 334 is
maintained deasserted by the 4G modem 320 until the start of the DL
sub-frame of Frame N+1 at time instant T6.
[0054] In response to the assertion of the RX_Active signal 334 by
the 4G modem 320, the WiFi/BT modem 310 in the 4G and WiFi
coexistence system 300 may not transmit WiFi between time instants
T0 and T1. Once the RX_Active signal 334 is deasserted, the WiFi/BT
modem 310 may transmit and/or receive WiFi until time instant
T6.
[0055] At time instant T3, the 4G modem 320 may begin processing
the UL sub-frame of Frame N. In this regard, the TX_Active signal
336 may be asserted by the 4G modem 320 at the start of the UL
sub-frame processing. The 4G modem 320 may determine, based on the
uplink MAP information in the DL/UL MAP information 410, whether
there is any data that needs to be decoded in the UL data zone 420.
In this example, no data is available to be decoded and the 4G
modem 320 maintains the TX_Active signal 336 asserted until the
processing of control information is completed at time instant T4.
While the UL sub-frame of Frame N ends at time instant T5, the
TX_Active signal 336 is maintained deasserted by the 4G modem 320
until the start of the UL sub-frame of Frame N+1 at time instant
T9.
[0056] In response to the assertion of the TX_Active signal 336 by
the 4G modem 320 during time instants T3 and T4, the WiFi/BT modem
310 may determine, in connection with a CCA operation, that the
energy detected in the physical medium is that of the WiMAX
transmission and that the physical medium may be available for WiFi
communication.
[0057] At time instant T6, the 4G modem 320 may begin processing
the DL sub-frame of Frame N+1. In this regard, the RX_Active signal
334 may be asserted by the 4G modem 320 at the start of the DL
sub-frame processing. The 4G modem 320 may determine, based on the
downlink MAP information in the DL/UL MAP information 410, whether
there is any data that needs to be decoded in the DL data PDUs 412.
In this example, there is no data that needs to be decoded and the
4G modem 320 maintains the RX_Active signal 334 asserted until the
reading of the DL/UL MAP information 410 is completed at time
instant T7. While the DL sub-frame of Frame N ends at time instant
T8, the RX_Active signal 334 is maintained deasserted by the 4G
modem 320 until the end of the UL sub-frame of Frame N+1 at time
instant T10.
[0058] In response to the assertion of the RX_Active signal 334 by
the 4G modem 320, the WiFi/BT modem 310 may not transmit WiFi
between time instants T6 and T7. Once the RX_Active signal 334 is
deasserted, the WiFi/BT modem 310 may transmit and/or receive WiFi
until time instant T10.
[0059] At time instant T8, the 4G modem 320 may begin processing
the UL sub-frame of Frame N+1. In this regard, the TX_Active signal
336 may be asserted by the 4G modem 320 at the start of the UL
sub-frame processing. The 4G modem 320 may determine, based on the
uplink MAP information in the DL/UL MAP information 410, whether
there is any data that needs to be decoded in the UL data zone 420.
In this example, there is data available to be decoded and the 4G
modem 320 maintains the TX_Active signal 336 asserted until the
data decoding is completed at time instant T10.
[0060] In response to the assertion of the TX_Active signal 336 by
the 4G modem 320 during time instants T9 and T10, the WiFi/BT modem
310 may determine, in connection with a CCA operation, that the
energy detected in the physical medium is that of the WiMAX
transmission and that the physical medium may be available for WiFi
communication.
[0061] While the time domain approach to 4G and WiFi/BT coexistence
in FIG. 4 is described in connection with WiMAX communication, the
invention need not be so limited. For example, a similar approach
may be utilized when TDD-LTE is utilized for 4 G communication. In
such instances, processing of the DL sub-frames and the UL
sub-frames may determine when to assert and deassert the RX_Active
signal 334 and/or the TX_Active signal 336, for example. A similar
approach may also be utilized when the 4 G communication is based
on FDD-LTE.
[0062] While the time domain approach to 4G and WiFi/BT coexistence
in FIG. 4 is described in connection with the high-level discrete
signaling mechanism of FIG. 3A, the invention need not be so
limited. For example, a similar mechanism or other signaling
mechanisms may be utilized to provide the functionality achieved by
the high-level discrete signaling mechanism of FIG. 3A.
[0063] In addition, while the time domain approach to 4G and WiFi/B
coexistence in FIG. 4 is described in connection with the 4G and
WiFi/BT coexistence system 300 in FIG. 3A, the invention need not
be so limited. For example, a similar approach may be implemented
in the 4G and WiFi/BT coexistence system 350 shown in FIG. 3B and
in the 4G and WiFi/BT coexistence system 370 shown in FIG. 3C.
[0064] Moreover, while the time domain approach to 4G and WiFi/BT
coexistence in FIG. 4 applies to 4G and Bluetooth coexistence, it
may also apply to 4G and ZigBee coexistence, for example.
[0065] FIG. 5 is a flow diagram that illustrates exemplary steps
for a time domain approach to 4G and WiFi/BT coexistence, in
accordance with an embodiment of the invention. Referring to FIG.
5, there is shown a flow chart 500 in which, at step 510, a 4G
modem or other like device may receive a 4G downlink sub-frame. The
4G downlink sub-frame may be associated with WiMAX communication,
with TDD-LTE communication, and/or with FDD-LTE, for example. The
4G modem may be, for example, one of the modems that support 4 G
communication as described above with respect to the 4G and WiFi/BT
coexistence systems 300, 350, and 370.
[0066] At step 520, the 4G modem may disable WiFi transmission in a
WiFi modem based on information in the 4G downlink sub-frame. For
example, WiFi transmission may be disabled until the decoding of
data in the 4G downlink sub-frame is completed. The WiFi
transmission may be disabled by asserting a signal such as the
RX_Active signal 334, for example. The WiFi modem may be, for
example, one of the modems that support WiFi communication as
described above with respect to the 4G and WiFi/BT coexistence
systems 300, 350, and 370. The disabling of the WiFi transmission
may comprise disabling baseband operations in the WiFi modem and/or
disabling a power amplifier in a WiFi front end such as the WiFi/BT
front end 330.
[0067] At step 530, the 4G modem may enable the previously disabled
WiFi transmission once the decoding of data in the 4G downlink
sub-frame is completed. At step 540, a 4G up-link sub-frame may be
received next by the 4G modem. The WiFi transmission may remain
enabled during the 4G uplink sub-frame received by the 4G modem at
step 540.
[0068] At step 550, the 4G modem may transmit for at least a
portion of the 4G uplink sub-frame and may provide an indication to
the WiFi modem of the duration of such transmission. The WiFi modem
may utilize such information in carrying out CCA operations to
determine whether energy detected in the medium is from the 4G
transmission or from some other source.
[0069] FIG. 6 is a flow diagram that illustrates exemplary steps to
aggregate uplink transmissions in a 4G and WiFi/BT coexistence
system, in accordance with an embodiment of the invention.
Referring to FIG. 6, there is shown a flow chart 600 in which, at
step 610, a WiFi modem or other like device may generate an
indication of pending WiFi transmission traffic and may send the
indication to a 4G modem. The WiFi modem may be, for example, one
of the modems that support WiFi communication as described above
with respect to the 4G and WiFi/BT coexistence systems 300, 350,
and 370. Similarly, the 4G modem may be, for example, one of the
modems that support 4 G communication as described above with
respect to the 4G and WiFi/BT coexistence systems 300, 350, and
370. The indication may be, for example, the WiFi_Data_Pending
signal 338 described with respect to FIG. 3A.
[0070] At step 620, the 4G modem, in response to such indication,
may request from a base station that the bandwidth allocation be
modified to enable WiMAX communication through bursts of data. At
step 630, based on the bandwidth allocation received from the base
station, the 4G modem may aggregate WiMAX transmission so that
transmission occurs every N frames, for example. Fewer instances of
WiMAX transmission may result in reduced WiFi interference that may
allow the WiFi modem to address the backup in WiFi transmissions.
At step 640, the WiFi modem may begin to transmit some or all of
the pending traffic.
[0071] FIG. 7 is a flow diagram that illustrates exemplary steps
during WiMAX handoff scanning in a 4G and WiFi/BT coexistence
system, in accordance with an embodiment of the invention.
Referring to FIG. 7, there is shown a flow chart 700 in which, at
step 710, a 4G modem or other like device may enter into a handoff
scanning mode. The 4G modem may be, for example, one of the modems
that support 4 G communication as described above with respect to
the 4G and WiFi/BT coexistence systems 300, 350, and 370. In such
scenario, signals from a current base station may be already weak
in relation to scan thresholds and disabling a WiFi modem during
handoff scanning may not be necessary. The WiFi modem may be, for
example, one of the modems that support WiFi communication as
described above with respect to the 4G and WiFi/BT coexistence
systems 300, 350, and 370.
[0072] At step 720, the 4G modem may scan N out of M frames
received. In this regard, the 4G modem may utilize at least the
first 2 symbols received in each of the N frames scanned. In some
embodiments of the invention, N=2 and M=20. At step 730, during
frame scanning, the 4G modem may indicate to a WiFi modem to
disregard any indication to disable WiFi transmission. When the 4G
modem generates a signal such as the RX_Active signal 334, and when
such signal is asserted on the WiFi modem during frame scanning,
the 4G modem may generate some other indication to the WiFi modem
to disregard the disabling of the WiFi transmission indicated by
the RX_Active signal 334. In some embodiments of the invention, the
4G modem may deassert the RX_Active signal 334 during frame
scanning.
[0073] The various steps described above with respect to FIGS. 5,
6, and 7 may be applied to those instances in which Bluetooth
communication is utilized instead of WiFi communication in
coexistence with 4 G communication.
[0074] Another embodiment of the invention may provide a
non-transitory machine and/or computer readable storage and/or
medium, having stored thereon, a machine code and/or a computer
program having at least one code section executable by a machine
and/or a computer, thereby causing the machine and/or computer to
perform the steps as described herein for a time domain approach to
4G WiMAX/LTE and WiFi coexistence.
[0075] Accordingly, the present invention may be realized in
hardware, software, or a combination of hardware and software. The
present invention may be realized in a centralized fashion in at
least one computer system or in a distributed fashion where
different elements may be spread across several interconnected
computer systems. Any kind of computer system or other apparatus
adapted for carrying out the methods described herein is suited. A
typical combination of hardware and software may be a
general-purpose computer system with a computer program that, when
being loaded and executed, controls the computer system such that
it carries out the methods described herein.
[0076] The present invention may also be embedded in a computer
program product, which comprises all the features enabling the
implementation of the methods described herein, and which when
loaded in a computer system is able to carry out these methods.
Computer program in the present context means any expression, in
any language, code or notation, of a set of instructions intended
to cause a system having an information processing capability to
perform a particular function either directly or after either or
both of the following: a) conversion to another language, code or
notation; b) reproduction in a different material form.
[0077] While the present invention has been described with
reference to certain embodiments, it will be understood by those
skilled in the art that various changes may be made and equivalents
may be substituted without departing from the scope of the present
invention. In addition, many modifications may be made to adapt a
particular situation or material to the teachings of the present
invention without departing from its scope. Therefore, it is
intended that the present invention not be limited to the
particular embodiment disclosed, but that the present invention
will include all embodiments falling within the scope of the
appended claims.
* * * * *