U.S. patent application number 16/430999 was filed with the patent office on 2020-12-10 for method and device to minimize interference in a converged lmr/lte communication device.
The applicant listed for this patent is MOTOROLA SOLUTIONS, INC. Invention is credited to BRADLEY M. HIBEN, BRUCE D. MUELLER, JOHN B. PRESTON.
Application Number | 20200389902 16/430999 |
Document ID | / |
Family ID | 1000004158011 |
Filed Date | 2020-12-10 |
United States Patent
Application |
20200389902 |
Kind Code |
A1 |
HIBEN; BRADLEY M. ; et
al. |
December 10, 2020 |
METHOD AND DEVICE TO MINIMIZE INTERFERENCE IN A CONVERGED LMR/LTE
COMMUNICATION DEVICE
Abstract
A method and converged LMR/LTE communications device provide for
minimizing interference in the converged LMR/LTE communications
device that operates in a land mobile radio (LMR) narrowband
communication system and a long term evolution (LTE) broadband
communication system. The converged LMR/LTE communications device
detects, using an electronic processing device, that the converged
LMR/LTE communications device is operating in the first LTE band
and the first LMR band. The converged LMR/LTE communications device
determines that a first LMR received signal strength indicator
(RSSI) at the converged LMR/LTE communications device is less than
a first LMR threshold signal strength and disables at least one LTE
application based upon the first LMR RSSI being less than the LMR
threshold signal strength.
Inventors: |
HIBEN; BRADLEY M.; (GLEN
ELLYN, IL) ; MUELLER; BRUCE D.; (PALATINE, IL)
; PRESTON; JOHN B.; (PLANTATION, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MOTOROLA SOLUTIONS, INC |
Chicago |
IL |
US |
|
|
Family ID: |
1000004158011 |
Appl. No.: |
16/430999 |
Filed: |
June 4, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 72/087 20130101;
H04B 17/318 20150115; H04W 72/082 20130101; H04W 72/0453 20130101;
H04W 76/30 20180201; H04W 28/0257 20130101 |
International
Class: |
H04W 72/08 20060101
H04W072/08; H04W 72/04 20060101 H04W072/04; H04W 28/02 20060101
H04W028/02; H04W 76/30 20060101 H04W076/30; H04B 17/318 20060101
H04B017/318 |
Claims
1. A method for minimizing interference in a converged LMR/LTE
communications device that operates in a land mobile radio (LMR)
narrowband communication system and a long term evolution (LTE)
broadband communication system, the method comprising: determining
a first LMR received signal strength indicator (RSSI) at the
converged LMR/LTE communications device; determining a first LTE
Reference Symbol Receive Power (RSRP) at the converged LMR/LTE
communications device; determining whether an intersection of the
first LMR RSSI and the first LTE RSRP falls within an interference
range on a predetermined graph, the predetermined graph based upon
an LMR frequency band and an LTE frequency band that the converged
LMR/LTE communications device is currently utilizing; and
decreasing bit rate for LTE transmissions for the converged LMR/LTE
communications device responsive to determining that the
intersection of the first LMR RSSI and the first LTE RSRP is within
the interference range.
2. The method of claim 1, wherein the step of decreasing comprises
setting a capped bit rate for LTE transmissions for the converged
LMR/LTE communications device.
3. The method of claim 2, wherein the capped bit rate is decreased
to a predetermined bit rate, the predetermined bit rate limiting
LTE uplink transmitted signal interference.
4. The method of claim 2, the method further comprising the step of
utilizing the capped bit rate to limit the bit rate.
5. The method of claim 4, wherein the bit rate comprises a
predetermined percentage of the capped bit rate.
6. The method of claim 1, wherein the step of decreasing comprises
disabling an LTE application on the converged LMR/LTE
communications device.
7. The method of claim 6, wherein the step of disabling an LTE
application on the converged LMR/LTE communications device
comprises disabling the LTE application using a destination IP
address of the LTE application.
8. The method of claim 6, wherein the step of disabling an LTE
application on the converged LMR/LTE communications device
comprises instructing the LTE application to stop producing LTE
traffic for a first period of time.
9. The method of claim 1, wherein the LMR frequency band comprises
the 700 MHz band and wherein the LTE frequency band is band 14.
10. The method of claim 1, wherein the LMR frequency band comprises
the 700 MHz band and wherein the LTE frequency band is band 13.
11. The method of claim 1, wherein the LMR frequency band comprises
the 800 MHz band and wherein the LTE frequency band is band 5.
12. The method of claim 1, wherein the LTE frequency band comprises
one of Band 5, Band 13, or Band 14.
13. The method of claim 12, the method further comprising the step
of detecting that the converged LMR/LTE communications device has
transitioned to a band other than one of Band 5, Band 13, or Band
14.
14. The method of claim 13, the method further comprising the step
of increasing the bit rate for LTE transmissions for the converged
LMR/LTE communications device.
15. The method of claim 1, wherein the LTE transmissions comprise
location update data and non-location data, and wherein the step of
decreasing the bit rate for LTE transmissions comprises decreasing
the bit rate for the non-location data.
16. A converged LMR/LTE communications device for minimizing
interference when operating in a land mobile radio (LMR) narrowband
communication system and a long term evolution (LTE) broadband
communication system, the converged LMR/LTE communications device
comprising: a processor that performs: determining a first LMR
received signal strength indicator (RSSI) at the converged LMR/LTE
communications device; determining a first LTE Reference Symbol
Receive Power (RSRP) at the converged LMR/LTE communications
device; determining whether an intersection of the first LMR RSSI
and the first LTE RSRP falls within an interference range on a
predetermined graph, the predetermined graph based upon an LMR
frequency band and an LTE frequency band that the converged LMR/LTE
communications device is currently utilizing; and decreasing bit
rate for LTE transmissions for the converged LMR/LTE communications
device when responsive to determining that the intersection of the
first LMR RSSI and the first LTE RSRP is within the interference
range.
17. The converged LMR/LTE communications device of claim 16,
wherein the step of decreasing comprises setting a capped bit rate
for LTE transmissions for the converged LMR/LTE communications
device.
18. The converged LMR/LTE communications device of claim 17,
wherein the processor is further configured to utilize the capped
bit rate to limit the bit rate, and wherein the bit rate comprises
a predetermined percentage of the capped bit rate.
19. The converged LMR/LTE communications device of claim 16,
wherein the step of decreasing comprises disabling an LTE
application on the converged LMR/LTE communications device.
20. The converged LMR/LTE communications device of claim 16,
wherein the LTE transmissions comprise location update data and
non-location data, and wherein the step of decreasing the bit rate
for LTE transmissions comprises decreasing the bit rate for the
non-location data.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to mobile devices,
which are also called Mobile Stations (MS) in cellular system
terminology or User Equipment (UE) in cellular systems specified by
the Third Generation Partnership Project (3GPP) or Portable Devices
or even just Portables in Land Mobile Radio (LMR) community. In
particular, certain mobile devices, commonly referred to as
converged communication devices, or simply converged devices, can
operate on multiple communication systems, even communication
systems that utilize different portions of the RF spectrum. These
mobile devices can utilize, for example, Land Mobile Radio (LMR)
for voice communications and cellular Long Term Evolution (LTE) for
data communications.
[0002] However, utilizing these two RF bands can result in
interference, which can hamper communications and even prevent
usable communication from occurring. This problem can be worse when
the LMR signal is weak, especially in correspondence with certain
LTE frequency bands.
[0003] Therefore, a need exists for a method and system to minimize
interference in a converged communications device. More
particularly, a need exists for a method and system to minimize
interference in a converged communications device that operates in
an LMR narrowband communication system and an LTE broadband
communication system.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0004] The accompanying figures, where like reference numerals
refer to identical or functionally similar elements throughout the
separate views, which together with the detailed description below
are incorporated in and form part of the specification and serve to
further illustrate various embodiments of concepts that include the
claimed invention, and to explain various principles and advantages
of those embodiments.
[0005] FIG. 1 depicts a system diagram of a communication system in
accordance with an exemplary embodiment of the present
invention.
[0006] FIG. 2 depicts the spectrum environment of the communication
system in accordance with an exemplary embodiment of the present
invention.
[0007] FIG. 3 depicts a schematic of a converged communication
device in accordance with an exemplary embodiment of the present
invention.
[0008] FIG. 4 depicts a graph in accordance with an exemplary
embodiment of the present invention.
[0009] FIG. 5 depicts a flowchart in accordance with an exemplary
embodiment of the present invention.
[0010] FIG. 6 depicts a flowchart in accordance with an exemplary
embodiment of the present invention.
[0011] Skilled artisans will appreciate that elements in the
figures are illustrated for simplicity and clarity and have not
necessarily been drawn to scale. For example, the dimensions of
some of the elements in the figures may be exaggerated relative to
other elements to help to improve understanding of embodiments of
the present invention.
[0012] The apparatus and method components have been represented
where appropriate by conventional symbols in the drawings, showing
only those specific details that are pertinent to understanding the
embodiments of the present invention so as not to obscure the
disclosure with details that will be readily apparent to those of
ordinary skill in the art having the benefit of the description
herein.
DETAILED DESCRIPTION OF THE INVENTION
[0013] In accordance with an exemplary embodiment, data flow and
data rate of an LTE modem are modified based upon channel
conditions. For example, LTE applications can be enabled or
disabled according to channel conditions. Applications that cause
low amounts of interference, such as location update messages, are
preferably enabled under more channel conditions than applications
that generate a high amount of interference, such as streaming
video. As a result, LTE and LMR can be operated simultaneously over
at least a part of the coverage area rather than in strict
exclusion of one or the other.
[0014] Factors taken into consideration when determining whether to
slow or stop some or all LTE data transfers include the LTE RSRP
(Reference Symbol Receive Power), the LMR RSSI (Receive Signal
Strength Indicator), the LTE Band, and the LMR channel. In
accordance with exemplary embodiments, the LTE bands impacted are
bands 5, 13, and 14. As channel conditions improve, additional
applications are preferably enabled. The combination of LMR band,
LTE band, signal strength, transmit power, as well as data
transmission characteristics are each inputs into a function to
preferably predict interference likelihood.
[0015] In a further exemplary embodiment, the data rate is
controlled using Quality of Service (QoS) priority to data streams
from applications to prioritize their transmission.
[0016] In accordance with an exemplary embodiment, all applications
are allowed regardless of channel conditions for LTE bands 2, 4 and
12, since these LTE bands typically do not interfere with LMR radio
frequencies.
[0017] FIG. 1 depicts a system diagram of a communication system
100 in accordance with an exemplary embodiment of the present
invention. Communication system 100 preferably includes a converged
LMR/LTE communication device 101, an LMR narrowband communication
system 103, and an LTE broadband communication system 105.
[0018] Converged LMR/LTE communication device 101 is coupled with
LMR narrowband communication system 103, and an LTE broadband
communication system 105. Converged LMR/LTE communication device
101 is sometimes referred to as a subscriber unit. It should be
understood that communication system 100 would typically include a
plurality of communication devices, but only one, converged LMR/LTE
communication device 101 is depicted in FIG. 1 for clarity.
[0019] LMR narrowband communication system 103 is a
person-to-person voice communication system comprising two-way
radio transceivers which can be mobile, installed in vehicles, or
portable. LMR communication networks are widely used by public
safety and first responder organizations such as police, fire, and
ambulance services, and other governmental organizations. LMR
narrowband communication system 103 can alternately be designed for
private commercial use. Most LMR communication networks are
half-duplex, with multiple mobile devices sharing a single radio
channel, so only one mobile device can transmit at a time. The
mobile device is normally in receiving mode so the user can hear
other radios on the channel. When a user wants to talk, for example
in a talkgroup call, the user presses a push to talk button on his
mobile device, which turns on the transmitter of the mobile device.
LMR narrowband communication system 103 preferably includes
dispatch consoles, data applications, and RF conventional or
trunked sites. LMR narrowband communication system 103 includes
various network elements that assist in facilitating communication,
such as base stations and controllers, but they are not shown for
clarity purposes.
[0020] LTE broadband communication system 105 is a cellular network
that supports packet switching over an-IP network. LTE broadband
communication system 105 preferably includes System Architecture
Evolution (SAE), which includes an Evolved Packet Core (EPC)
network. Together LTE and SAE comprise the Evolved Packet System
(EPS). LTE broadband communication system 105 also preferably
comprises an eNodeB (evolved node B), an MIME (Mobile Management
Entity), an HSS (Home Subscriber Server), an SGW (Serving GateWay),
and a PGW (Packet data network GateWay).
[0021] FIG. 2 depicts the spectrum environment 200 that results in
interference from LTE to LMR. The environment shown is specifically
a portion of the U.S. 700 MHz and 800 MHz frequency bands which are
used for LMR and cellular services. LMR channels typically use
narrow bandwidth technologies such as APCO Project 25 that use 25
kHz or 12.5 kHz channels. The cellular bands employ several
technologies but are shifting to LTE over time. The frequency
limits of the various service allocations are shown by the numbers
201 which are given in MHz.
[0022] FIG. 2 shows that an exemplary LMR communication system 103
utilizes base stations at tower site 205 that transmits signals 206
on frequencies in LMR receive bands 207 and 208. At the same time,
LTE transmitters in transmit bands 210 transmit LTE signals 211 to
a cellular site 212. The LMR receivers can preferably receive
signals 206 weaker than -110 dBm while the LTE transmitters can
preferably transmit signals 211 at power levels up to +23 dBm. In
this exemplary embodiment, the frequency gap 213 between LMR
receive and LTE transmit bands is only 2 MHz wide, which is not
enough for practical filters to attenuate out of band emissions 214
sufficiently to eliminate interference from the LTE transmitters to
the LMR receivers in converged device 101.
[0023] FIG. 3 shows converged communication device 101 in
accordance with an exemplary embodiment. LMR radio 301 and LTE
radio 302 are used give converged communication device 101 wireless
connectivity to systems 103 and 105. Systems 103 and 105 provide
many services, such as Internet connectivity and voice dispatch
service. LMR and LTE radios are well known in the art and are
available as modules and chipsets. Radios 103 and 105 are used to
send and receive data from output port 330, which represents the
user interface of converged communication device 101 which may use
audio, visual, other wireless protocols such as Wi-Fi and
Bluetooth, button pushes, knob and switch positions, haptics and
screen touches to provide media to the user and receive media and
control information from the user.
[0024] LMR Radio 301 receives electronic signals from one or more
wired or wireless communication networks, such as LMR narrowband
communication system 103 and LTE broadband communication system
105, or from other communication devices.
[0025] Converged communication device 101 preferably includes
processor 303 which executes methods to minimize interference in
converged LMR/LTE communications device 101. Processor 303 may
include a microprocessor, application-specific integrated circuit
(ASIC), field-programmable gate array, or another suitable
electronic device. The processor preferably includes a database 305
that can include one or more non-transitory computer-readable
media, and may include a program storage area and a data storage
area. The program storage area and the data storage area can
include combinations of different types of memory, as described
herein. In the embodiment illustrated, database 304 stores, among
other things, instructions for the processor to carry out the
methods.
[0026] The processor executes applications 321 that provide useful
content and functions for the device user. Examples of applications
are location update, voice command, image transfer, streaming
voice, streaming video and firmware download. The applications
utilize a communications stack provided by processor 303 which
preferably includes a UDP/TCP layer 322 and an IP layer 323. A
traffic control function 324 is provided by the operating system
which may be Android or another suitable mobile operating system.
The traffic control function can limit throughput in general or to
individual UDP/TCP ports and thus reduce or even stop traffic from
going to the LTE radio 302 over interface 325.
[0027] The traffic control function responds to input 320 from
interference methods block 304. Interference methods block 304
preferably determines the throughput to allow in response to input
310 from the LMR radio and input 311 from the LTE radio. Input 310
may comprise a received signal strength indication (RSSI) that
indicates the signal strength of the desired LMR signal. In
addition, input 310 may include the frequency of the LMR channel
that is being received and the whether the LMR radio is receiving
call or transmitting. Input 311 may include the reference symbol
received power (RSRP), which is used by the transmitter power
control circuit of the LTE radio. In addition, input 311 may
include the band that the LTE radio is using at the present time.
Inputs 310 and 311 are used in interference method 304 along with
information stored in database 304 to determine the throughput that
the traffic control function shall allow such that interference
from LTE transmissions are reduced to an acceptable level.
[0028] In an alternative exemplary embodiment, interference methods
304 activates and deactivates applications over interface 321
rather than limiting throughput with traffic control. In this case,
database 305 stores information about each application and the
degree of interference produced given the values of inputs 310 and
311 and activates only the applications that can send data over LTE
without resulting in unacceptable interference. In this exemplary
embodiment, interface 320 is not used.
[0029] In either case, the interference is controlled without
directly controlling the MAC or PHY layers of either LMR radio 301
or LTE radio 302. On the contrary, the interference is reduced by
control of the data input to LTE radio 302 responsive to the
channel conditions of the radio paths as represented by signals 310
and 311.
[0030] FIG. 4 depicts a graph 400 in accordance with an exemplary
embodiment of the present invention. Graph 400 depicts the LTE
Signal Strength along X axis 410 and the LMR Signal Strength along
Y axis 420. In the exemplary embodiment depicted in FIG. 4, the LTE
Signal Strength and the LMR Signal Strength are measured in dBm. In
the exemplary embodiment depicted in FIG. 4, the LMR frequency is
774 MHZ and the LTE band is Band 13. Graph 400 shows the LMR signal
strength required for a given set of parameters. In an exemplary
embodiment, these parameters include the LMR frequency, the LTE
band, an LTE data profile, and LMR/LTE antenna coupling. It should
be understood that a similar graph can be produced with any set of
parameters listed above.
[0031] It should be understood that the RSSI and RSRP are
indications of the received signal strength. Therefore, a higher
signal strength received generally means that the mobile device is
near the base station. Since the mobile device is located near the
base station, the power needed to transmit a signal to the base
station is relatively low when the received strength is high.
Conversely, when the received signal strength is low, the mobile
device is most likely not near the base station, and will
correspondingly need to transmit signals to the base station at a
relatively high power.
[0032] Graph 400 is preferably created by utilizing a testing
converged LMR/LTE communication device. In accordance with an
exemplary embodiment, the testing converged LMR/LTE communication
device is programmed for the LMR frequency and the LTE band being
evaluated. In this exemplary embodiment, the testing converged
LMR/LTE communication device is testing uplink data utilizing
eighty byte packets, such as short messages. For each LMR RSSI and
LTE RSRP, the point at which a 1% audio impact rate is plotted on
the graph. This process is repeated a sufficient number of times
such that a threshold line 450 can be generated.
[0033] Threshold line 450 separates two ranges, interference range
440 and noninterference range 430, from each other. When a
converged device, such as converged LMR/LTE communication device
101, is within noninterference range 430 LTE transmissions could be
transmitted without modification. When converged device, such as
converged LMR/LTE communication device 101, is within interference
range 440, the bit rate for transmissions from converged LMR/LTE
communication device 101 are decreased. In a first exemplary
embodiment, the bit rate is decreased to zero by blocking all LTE
transmissions from converged LMR/LTE communication device 101. In a
second exemplary embodiment, certain LTE applications are disabled
while others remain enabled, thereby decreasing the transmission
bit rate for converged LMR/LTE communication device 101. In a third
exemplary embodiment, the transmission bit rate for LTE
transmission of converged LMR/LTE communication device 101 is
decreased. By decreasing the LTE transmission bit rate, the
interference present for LMR communications is lowered. This is
especially important for LMR voice, since LMR voice may be used for
public safety voice communications, and it is extremely
disadvantageous to have interference disrupting such important
voice communications.
[0034] In accordance with an exemplary embodiment, a set of graphs
similar to graph 400 are used. In this exemplary embodiment, the
additional graphs would be for the used LMR frequency and LTE band
and would preferably go from full data rate LTE to a minimum
useable data rate, with a plurality of data rates between full data
rate and the minimum useable data rate. An exemplary set of graphs
may include graphs for LMR frequencies 769 MHz, 772 MHz, 774 MHz,
775 MHz with LTE bands 13 and 14, LMR frequencies of 851 MHz, 852
MHz 854 MHz, 857 MHz and 860 MHz with LTE band 5, data profiles of
80 byte messages (Small Messages application), 15 kilobyte messages
(such as a voice based inquiry system), 130 kilobyte message (such
as an Image Transfer application), fifty 80 byte packets-per-second
(such as a Voice Streaming uplink application), thirty 1500 byte
packets-per-second (such as a Video Streaming uplink application),
10 Megabyte download (such as an over-the-air (OTA) Update
application), and 10 dB antenna isolation. In this exemplary
embodiment, there would be seventy eight graphs, which are
preferably stored in database 305 in a form suitable for processor
303 to read and perform interference methods 304. Interpolation may
be used to account for frequencies, data profiles and signal
strengths that are between those stored in database 305.
[0035] In an exemplary embodiment, the full data rate graph would
have the smallest noninterference range. Using the parameters
above, it would be determined if the converged LMR/LTE
communication device is in that noninterference range. If it is
not, the current parameters would be compared against each of the
graphs for this LMR frequency and LTE band combination. Once the
parameters indicate that the converged LMR/LTE communication device
is located within a noninterference range for a graph, preferably
set the bit rate to the corresponding bit rate.
[0036] Upon reaching the graph with the minimum useable data rate,
if the converged LMR/LTE communication device is not within the
noninterference range on this graph, set the LTE data rate to zero,
effectively turning off LTE transmissions. This process would be
repeated periodically, as the conditions can change over time.
[0037] Thus, interference is preferably managed without access to
the LTE or LMR scheduling algorithms, without deactivating the LTE
modem, and without switching bands or rerouting application data.
In accordance with an exemplary embodiment, as converged LMR/LTE
communication device 101 moves throughout the coverage area it will
have more LTE throughput when it is closer to LMR and/or LTE base
sites but will have only slightly reduced LMR audio quality because
no more than 1% of the LTE messages impact the audio quality.
[0038] FIG. 5 depicts a flowchart in accordance with an exemplary
embodiment of the present invention.
[0039] Converged LMR/LTE communication device 101 determines (501)
a first LMR RSSI.
[0040] Converged LMR/LTE communication device 101 determines (502)
a first LTE RSRP.
[0041] Converged LMR/LTE communication device 101 determines (503)
other parameters necessary for this flowchart. In an exemplary
embodiment, these parameters include antenna coupling and an
allowable data rate.
[0042] Converged LMR/LTE communication device 101 determines (504)
if the intersection of the first LMR RSSI and the first LTE RSRP on
graph 400 is within the noninterference range 430 for the LMR
frequency, the LTE band currently being used by converged LMR/LTE
communication device 101, and the other parameters determined at
step 503.
[0043] If converged LMR/LTE communication device 101 is within the
noninterference range 430 as determined at step 504, converged
LMR/LTE communication device 101 is in an area and with parameters
that will allow converged LMR/LTE communication device 101 to
transmit LTE data with an acceptable amount of interference.
Converged LMR/LTE communication device 101 decreases (506) the bit
rate for LTE transmissions to the level that was determined at step
503. The process then ends (599).
[0044] If converged LMR/LTE communication device 101 was not in a
noninterference range as determined at step 504, then converged
LMR/LTE communication device 101 is in an area that will not allow
acceptable LTE transmissions. Converged LMR/LTE communication
device 101 determines (505) if it is at a minimum useable data
rate. If so, then no lower data rates for LTE transmissions will be
acceptable, and since the current parameters do not allow
acceptable LTE transmissions, converged LMR/LTE communication
device 101 sets (507) the LTE data rate to zero. This effectively
stops LTE transmission from converged LMR/LTE communication device
101. The process then ends (599).
[0045] If converged LMR/LTE communication device 101 determines at
step 505 that it is not at the minimum useable data rate, then
there are lower data rates that could be acceptable, and the
process returns to step 501 to continue the process.
[0046] FIG. 6 depicts a flow chart of a method for minimizing
interference in a converged LMR/LTE communications device that
operates in a land mobile radio (LMR) narrowband communication
system and a long term evolution (LTE) broadband communication
system. The steps depicted below are preferably carried out by
processor 303 in Converged LMR/LTE communication device 101.
[0047] FIG. 6 depicts an exemplary embodiment depicting three
general conditions. In the first condition, generally depicted in
decision blocks 602 and 612, the converged LMR/LTE communications
device is operating at band 14 in the LTE broadband communication
system and is operating in the 700 MHz band in the LMR narrowband
communication system. In the second condition, generally depicted
in decision blocks 603-606 and processes 613, 615, and 616, the
converged LMR/LTE communications device is operating at band 13 in
the LTE broadband communication system and is operating in the 700
MHz band in the LMR narrowband communication system. In the third
condition, depicted in process 613, the converged LMR/LTE
communications device is operating at band 4 in the LTE broadband
communication system and is operating in the 800 MHz band in the
LMR narrowband communication system.
[0048] Converged LMR/LTE communication device 101 determines (601)
the LTE band currently being used. In an exemplary embodiment,
converged LMR/LTE communication device 101 determines the LTE band
currently being used by making a software system call to the
operating system, for example, an Android operating system
operating on processor 305.
[0049] Converged LMR/LTE communication device 101 determines (602)
if the LTE band is Band 14. If the LTE band is Band 14, Converged
LMR/LTE communication device 101 determines (612) if first
parameters are met. In accordance with an exemplary embodiment,
first parameters are met when the RSRP is greater than or equal to
-95 dBm or if RSSI is greater than or equal to -100 dBm. RSRP is
the power of the LTE Reference Signals spread over the full
bandwidth and narrowband. A minimum of 20 dB SINR (of the S-Synch
channel) is needed to detect RSRP/RSRQ. At some point converged
LMR/LTE communication device 101 is so far from the LTE site that
the LTE signal has insufficient signal strength, which typically
occurs at RSRP of around -120 dBm.
[0050] If the first parameters are met as determined in step 612,
Converged LMR/LTE communication device 101 enables (613) all LTE
applications. In an exemplary embodiment, this is accomplished by
setting the uplink bit rate to unlimited. If the first parameters
are not met as determined in step 612, Converged LMR/LTE
communication device 101 determines (622) if the RSSI is greater
than or equal to -100 dBm.
[0051] If the RSSI is greater than or equal to -100 dBm as
determined at step 622, Converged LMR/LTE communication device 101
enables (632) a first subset of LTE Applications. In accordance
with an exemplary embodiment, the first subset of LTE applications
comprises small messages, Virtual Partner messages, streaming video
uplinks, streaming voice uplinks, and Over-the-Air (OTA) updates.
In a second exemplary embodiment, the first subset of LTE
applications comprises LTE application that have an uplink bit rate
less than 380 kbps. The process then ends (699).
[0052] If the RSSI is not greater than or equal to -100 dBm as
determined at step 622, Converged LMR/LTE communication device 101
determines (642) if the RSRP is greater than or equal to -120
dBm.
[0053] If the RSRP is greater than or equal to -120 dBm as
determined at step 642, Converged LMR/LTE communication device 101
enables (652) a fourth subset of LTE Applications. In accordance
with an exemplary embodiment, Converged LMR/LTE communication
device 101 enables small messages, streaming voice uplink, OTA
Updates, and sets the uplink bit rate to 32 kbps. The process then
ends (699).
[0054] If the RSRP is not greater than or equal to -120 dBm as
determined at step 642, Converged LMR/LTE communication device 101
blocks (626) all LTE transmissions. In accordance with an exemplary
embodiment, this is the equivalent of setting the uplink bit rate
to zero, which means that all ports are blocked effectively
blocked. The process then ends (699).
[0055] If the LTE band is not Band 14 as determined at step 602,
Converged LMR/LTE communication device 101 determines (503) if the
LTE band is Band 13. If the LTE band is not Band 13, Converged
LMR/LTE communication device 101 enables (613) all LTE
applications.
[0056] If the LTE band is not Band 14 as determined at step 602,
Converged LMR/LTE communication device 101 determines (604) if
second parameters are met. Second parameters are preferably met
when the RSSI is greater than or equal to -80 dBm and if the RSRP
is greater than or equal to -65 dBm or if the RSSI greater than or
equal to -2.4 times the RSRP times -236 dBm and if the RSRP is less
than or equal to -65 dBm.
[0057] If the second parameters are met as determined at step 604,
Converged LMR/LTE communication device 101 enables (613) all LTE
applications.
[0058] If the second parameters are not met as determined at step
604, Converged LMR/LTE communication device 101 determines (605) if
third parameters are met. Third parameters are preferably met when
the RSSI is greater than or equal to -90 dBm and the RSRP is
greater than or equal to -65 dBm or the RSSI is greater than or
equal to -2.0 time the RSRP -220 dBm and the RSRP is less than or
equal to -65 dBm. If the third parameters are met as determined at
step 605, Converged LMR/LTE communication device 101 enables (615)
a second subset of LTE applications. In accordance with an
exemplary embodiment, the second set of LTE applications comprises
streaming voice uplinks, Virtual Partner messages, and OTA updates.
In accordance with a second exemplary embodiment, the second subset
of LTE applications comprises LTE applications that have an uplink
bit rate of less than 32 kbps.
[0059] If the third parameters are not met as determined at step
605, Converged LMR/LTE communication device 101 determines (606) if
fourth parameters are met. Fourth parameters are preferably met
when the RSSI is greater than or equal to -1000 dBm and the RSRP is
greater than or equal to -95 dBm or the RSSI is greater than or
equal to -4.0 time the RSRP -220 dBm and the RSRP is less than or
equal to -95 dBm.
[0060] If the fourth parameters are met as determined at step 606,
Converged LMR/LTE communication device 101 enables (616) a third
subset of LTE applications. In accordance with an exemplary
embodiment the third subset of LTE applications comprises small
messages. In accordance with a second exemplary embodiment, the
third subset of LTE applications comprises LTE applications that
have a bit rate less than 680 bps.
[0061] If the fourth parameters are not met as determined at step
606, Converged LMR/LTE communication device 101 blocks (626) all
LTE transmissions. In accordance with an exemplary embodiment, this
is the equivalent of setting the uplink bit rate to zero, which
means that all ports are blocked effectively blocked. The process
then ends (699).
[0062] In the foregoing specification, specific embodiments have
been described. However, one of ordinary skill in the art
appreciates that various modifications and changes can be made
without departing from the scope of the invention as set forth in
the claims below. Accordingly, the specification and figures are to
be regarded in an illustrative rather than a restrictive sense, and
all such modifications are intended to be included within the scope
of present teachings. The benefits, advantages, solutions to
problems, and any element(s) that may cause any benefit, advantage,
or solution to occur or become more pronounced are not to be
construed as a critical, required, or essential features or
elements of any or all the claims. The invention is defined solely
by the appended claims including any amendments made during the
pendency of this application and all equivalents of those claims as
issued.
[0063] Moreover in this document, relational terms such as first
and second, top and bottom, and the like may be used solely to
distinguish one entity or action from another entity or action
without necessarily requiring or implying any actual such
relationship or order between such entities or actions. The terms
"comprises," "comprising," "has", "having," "includes",
"including," "contains", "containing" or any other variation
thereof, are intended to cover a non-exclusive inclusion, such that
a process, method, article, or apparatus that comprises, has,
includes, contains a list of elements does not include only those
elements but may include other elements not expressly listed or
inherent to such process, method, article, or apparatus. An element
preceded by "comprises . . . a", "has . . . a", "includes . . . a",
"contains . . . a" does not, without more constraints, preclude the
existence of additional identical elements in the process, method,
article, or apparatus that comprises, has, includes, contains the
element. The terms "a" and "an" are defined as one or more unless
explicitly stated otherwise herein. The terms "substantially",
"essentially", "approximately", "about" or any other version
thereof, are defined as being close to as understood by one of
ordinary skill in the art, and in one non-limiting embodiment the
term is defined to be within 10%, in another embodiment within 5%,
in another embodiment within 1% and in another embodiment within
0.5%. The term "coupled" as used herein is defined as connected,
although not necessarily directly and not necessarily mechanically.
A device or structure that is "configured" in a certain way is
configured in at least that way, but may also be configured in ways
that are not listed.
[0064] It will be appreciated that some embodiments may be
comprised of one or more generic or specialized electronic
processors (or "processing devices") such as microprocessors,
digital signal processors, customized processors and field
programmable gate arrays (FPGAs) and unique stored program
instructions (including both software and firmware) that control
the one or more processors to implement, in conjunction with
certain non-processor circuits, some, most, or all of the functions
of the method and/or apparatus described herein. Alternatively,
some or all functions could be implemented by a state machine that
has no stored program instructions, or in one or more application
specific integrated circuits (ASICs), in which each function or
some combinations of certain of the functions are implemented as
custom logic. Of course, a combination of the two approaches could
be used.
[0065] Moreover, an embodiment can be implemented as a
computer-readable storage medium having computer readable code
stored thereon for programming a computer (e.g., comprising an
electronic processor) to perform a method as described and claimed
herein. Examples of such computer-readable storage mediums include,
but are not limited to, a hard disk, a CD-ROM, an optical storage
device, a magnetic storage device, a ROM (Read Only Memory), a PROM
(Programmable Read Only Memory), an EPROM (Erasable Programmable
Read Only Memory), an EEPROM (Electrically Erasable Programmable
Read Only Memory) and a Flash memory. Further, it is expected that
one of ordinary skill, notwithstanding possibly significant effort
and many design choices motivated by, for example, available time,
current technology, and economic considerations, when guided by the
concepts and principles disclosed herein will be readily capable of
generating such software instructions and programs and ICs with
minimal experimentation.
[0066] The Abstract of the Disclosure is provided to allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, it can be seen that various
features are grouped together in various embodiments for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter lies in less than all features of a single
disclosed embodiment. Thus the following claims are hereby
incorporated into the Detailed Description, with each claim
standing on its own as a separately claimed subject matter.
* * * * *