Abstract:
A device including a transmitter, a receiver and an arbiter. The transmitter transmits a first signal. The first signal has a fundamental frequency in a first frequency band of a first wireless protocol. The receiver receives a second signal. The second signal has a fundamental frequency in a second frequency band of a second wireless protocol. The first frequency band is adjacent to or at least partially overlaps the second frequency band. The arbiter allows the transmitter to transmit the first signal in the first frequency band while the receiver receives the second signal in the second frequency band. The arbiter also, if a power level of the first signal is less than a first threshold, changes: a modulation and coding scheme of the transmitter for the first signal; a modulation and coding scheme of the receiver for the second signal; or a multiple input and multiple output rank.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Non-Provisional patent application Ser. No. 14/691,131, filed on Apr. 20, 2015, which is a continuation of U.S. Non-Provisional patent application Ser. No. 13/553,146, filed on Jul. 19, 2012 (now U.S. Pat. No. 9,014,751) which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/522,149, filed on Aug. 10, 2011, entitled “Use of Signal Power Levels for In-device Co-existence Scheduling,” the disclosures thereof incorporated by reference herein in their entirety. 
    
    
     FIELD 
     The present disclosure relates generally to the field of wireless communication. More particularly, the present disclosure relates to avoiding interference between different wireless communication technologies that use adjacent or overlapping frequency bands. 
     BACKGROUND 
     The popularity of multiple wireless communication technologies for handheld platforms has created a need to integrate wireless communication technologies on a single wireless communication device. However, the frequency bands of some of these technologies are close enough to result in interference. For example, the un-licensed 2.4 GHz Industrial, Scientific and Medical (ISM) frequency band is adjacent to some of the bands used by Mobile Wireless Standards (MWS) technologies to result in adjacent channel interference. In many electronic devices such as smartphones, both ISM and MWS technologies are implemented in the same device. For example, a smartphone may employ LTE (Long Term Evolution) for phone calls, WiFi for local area networking, and Bluetooth for headsets. LTE transmissions from the smartphone will cause adjacent channel interference with incoming Bluetooth and WiFi signals. Similarly, Bluetooth and WiFi transmissions from the smartphone will cause adjacent channel interference with incoming LTE signals. This adjacent channel interference can significantly degrade performance not only at the smartphone, but also at connected MWS base stations. 
     SUMMARY 
     In general, in one aspect, an embodiment features an apparatus comprising: a transmitter configured to transmit, according to a first protocol, first wireless signals in a first frequency band; and a receiver configured to receive, according to a second protocol, second wireless signals in a second frequency band, wherein the second frequency band is adjacent to or overlaps the first frequency band; and an arbiter configured to allow the transmitter to transmit the first wireless signals according to the first protocol while the receiver receives the second wireless signals according to the second protocol responsive to at least one of i) a signal power level of the first wireless signals being less than a first signal power threshold; and ii) a signal power level of the second wireless signals being greater than a second signal power threshold. 
     Embodiments of the apparatus can include one or more of the following features. In some embodiments, the first protocol is a Mobile Wireless Standards (MWS) protocol; and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the first protocol is an Industrial, Scientific and Medical (ISM) band protocol; and the second protocol is a Mobile Wireless Standards (MWS) protocol. In some embodiments, each of the first protocol and the second protocol, is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the arbiter is further configured to change a receive mode for the receiver responsive to at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold, and ii) the signal power level of the second wireless signals not being greater than the second signal power threshold. In some embodiments, the arbiter is further configured to change at least one of a transmit mode and a signal power level for the transmitter based on at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold, and i) the signal power level of the second wireless signals not being greater than the second signal power threshold. In some embodiments, the arbiter is further configured not to allow the transmitter to transmit the first wireless signals according to the first protocol while the receiver receives the second wireless signals according to the second protocol responsive to i) a priority of the first wireless signals being less than a priority of the second wireless signals, and ii) at least one of a) the signal power level of the first wireless signals not being less than the first signal power threshold, and b) the signal power level of the second wireless signals not being greater than the second signal power threshold. Some embodiments comprise an electronic device comprising the apparatus of. 
     In general, in one aspect, an embodiment features a method comprising: transmitting, according to a first protocol, first wireless signals in a first frequency band while receiving, according to a second protocol, second wireless signals in a second frequency band that is adjacent to or overlaps the first frequency band, responsive to at least one of i) a signal power level of the first wireless signals being less than a first signal power threshold, and ii) a signal power level of the second wireless signals being greater than a second signal power threshold. 
     Embodiments of the method can include one or more of the following features. In some embodiments, the first protocol is a Mobile Wireless Standards (MWS) protocol; and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the first protocol is an Industrial, Scientific and Medical (ISM) band protocol; and the second protocol is a Mobile Wireless Standards (MWS) protocol. Some embodiments comprise changing a receive mode for receiving the second wireless signals responsive to at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold, and ii) the signal power level of the second wireless signals not being greater than the second signal power threshold. Some embodiments comprise changing at least one of a transmit mode and a signal power level for transmitting the first wireless signals responsive to at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold, and ii) the signal power level of the second wireless signals not being greater than the second signal power threshold. Some embodiments comprise not transmitting the first wireless signals while receiving the second wireless signals responsive to a priority of the first wireless signals being less than a priority of the second wireless signals and at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold; and ii) the signal power level of the second wireless signals not being greater than the second signal power threshold. 
     In general, in one aspect, an embodiment features computer-readable media embodying instructions executable by a computer in an electronic device to perform functions comprising: causing the electronic device to transmit, according to a first protocol, first wireless signals in a first frequency band while the electronic device receives, according to a second protocol, second wireless signals in a second frequency band that is adjacent to or overlaps the first frequency band, responsive to at least one of i) a signal power level of the first wireless signals being less than a first signal power threshold; and ii) a signal power level of the second wireless signals being greater than a second signal power threshold. 
     Embodiments of the computer-readable media can include one or more of the following features. In some embodiments, the first protocol is a Mobile Wireless Standards (MWS) protocol; and the second protocol is an Industrial, Scientific and Medical (ISM) band protocol. In some embodiments, the first protocol is an Industrial, Scientific and Medical (ISM) band protocol; and the second protocol is a Mobile Wireless Standards (MWS) protocol. In some embodiments, the functions further comprise: changing a receive mode for receiving the second wireless signals responsive to at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold, and ii) the signal power level of the second wireless signals not being greater than the second signal power threshold. In some embodiments, the functions further comprise: changing at least one of a transmit mode and a signal power level for transmitting the first wireless signals responsive to at least one of i) the signal power level of the first wireless signals not being less than the first signal power threshold, and ii) the signal power level of the second wireless signals not being greater than the second signal power threshold. In some embodiments, the functions further comprise: not transmitting the first wireless signals while receiving the second wireless signals responsive to i) a priority of the first wireless signals being less than a priority of the second wireless signals, and ii) at least one of a) the signal power level of the first wireless signals not being less than the first signal power threshold; and b) the signal power level of the second wireless signals not being greater than the second signal power threshold. 
     The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  shows elements of a communication system according to one embodiment. 
         FIG. 2  shows a process for the communication system of  FIG. 1  according to an embodiment that considers the signal power levels of LTE transmission and WiFi reception. 
         FIG. 3  shows a process for the communication system of  FIG. 1  according to an embodiment that considers the signal power levels of WiFi transmission and LTE reception. 
         FIG. 4  shows a process for the communication system of  FIG. 1  according to an embodiment that considers the signal power level of LTE transmission, but not the signal power level of WiFi reception. 
         FIG. 5  shows a process for the communication system of  FIG. 1  according to an embodiment that considers the signal power level of WiFi transmission, but not the signal power level of LTE reception. 
         FIG. 6  shows a process for the communication system of  FIG. 1  according to an embodiment that considers the signal power level of WiFi reception, but not the signal power level of LTE transmission. 
         FIG. 7  shows a process for the communication system of  FIG. 1  according to an embodiment that considers the signal power level of LTE reception, but not the signal power level of WiFi transmission. 
     
    
    
     The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears. 
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure provide coexistence among multiple wireless communication technologies based on the signal power levels of the wireless signals. In some cases, the wireless communication technologies use adjacent frequency bands, and so cause adjacent channel interference. For example, some bands used by Mobile Wireless Standards (MWS) technologies are adjacent to the Industrial, Scientific and Medical (ISM) frequency band. In other cases, the interference results from wireless communication technologies using frequency bands that partially or fully overlap. For example, both WiFi and Bluetooth use the ISM frequency band. 
       FIG. 1  shows elements of a communication system  100  according to one embodiment. Although in the described embodiments the elements of the communication system  100  are presented in one arrangement, other embodiments may feature other arrangements. For example, elements of the communication system  100  can be implemented in hardware, software, or combinations thereof. 
     Referring to  FIG. 1 , the communication system  100  includes a user equipment (UE)  102  capable of communications using multiple wireless technologies. The user equipment  102  can be implemented as any sort of electronic device capable of performing the functions described herein. For example, the user equipment  102  can be implemented as a smartphone, tablet computer, or the like. Elements of user equipment  102  can be implemented as one or more integrated circuits. 
     The user equipment  102  includes multiple transceivers employing different wireless technologies. In the example of  FIG. 1 , the transceivers include a Mobile Wireless Standards (MWS) transceiver and an Industrial, Scientific and Medical (ISM) band transceiver. In other embodiments, other numbers of transceivers and other combinations of wireless technologies can be employed instead. For example, the MWS transceivers can include Long Term Evolution (LTE) transceivers, Worldwide Interoperability for Microwave Access (WiMAX) transceivers, and the like, and the ISM band transceivers can include WiFi transceivers, Bluetooth transceivers, ZigBee transceivers, and the like. The transceivers can include two MWS transceivers or two ISM transceivers. The ISM band equipment can also include receive-only devices such as global positioning system (GPS) receivers, frequency modulation (FM) radio receivers, and the like. 
     In the example of  FIG. 1 , the transceivers include a WiFi media access controller (MAC)  104  and an LTE device  108 . Each transceiver communicates using one or more respective antennas. In particular, the WiFi MAC  104  uses one or more antennas  110 , and the LTE device  108  uses one or more antennas  114 . In some embodiments, one or more of the antennas  110 ,  114  can be combined. 
     The WiFi MAC  104  includes a receiver (WiFi Rx)  116  and a transmitter (WiFi Tx)  118 . The LTE device  108  includes a receiver (LTE Rx)  120  and a transmitter (LTE Tx)  122 . The WiFi MAC  104  uses antenna  110  to transmit and receive wireless WiFi protocol signals  124  (also referred to herein as WiFi signals  124 ). The LTE device  108  uses antenna  114  to transmit and receive wireless LTE protocol signals  126  (also referred to herein as LTE signals  126 ). 
     The user equipment  102  also includes an arbiter  128 . The arbiter  128  can be implemented as a processor. Processors according to various embodiments can be fabricated as one or more integrated circuits. The arbiter  128  receives information signals  130 ,  132  from the transceivers  104 ,  108 , and provides control signals  134 ,  136  to the transceivers  104 ,  108 . The arbiter  128  receives the information signals  130  from the WiFi MAC  104 , and provides the control signals  134  to the WiFi MAC  104 . The arbiter  128  receives the information signals  132  from the LTE device  108 , and provides the control signals  136  to the LTE device  108 . 
     The information signals  130 ,  132  include indications of the signal power levels of the wireless signals  124 ,  126 . In some embodiments, the information signals  130 ,  132  include indications of other factors such as the priorities of the traffic carried by the wireless signals  124 ,  126 , and the like. The indications of the signal power levels of the wireless signals  124 ,  126  can include the signal power levels of the wireless signals  124 ,  126  received by the receivers  116 ,  120 , the signal power levels of the wireless signals  124 ,  126  employed by the transmitters  118 ,  122  to transmit the wireless signals  124 ,  126 , and the like. The signal power levels can include present signal power levels, as well as planned future signal power levels. The signal power level of a wireless signal  124 ,  126  to be received by a receiver  116 ,  120  can be estimated based on system parameters, a history of received signal power levels, and the like. The history of received signal power levels can include an average of previous signal power levels, the latest instantaneous received signal power level, and the like. The signal power level of a wireless signal  124 ,  126  to be transmitted by a transmitter  118 ,  122  can be known in advance when controlled by a network, selected in advance by the transmitter  118 ,  122 , and the like. 
     The arbiter  128  employs the control signals  134 ,  136  to control the operation of the transceivers  104 ,  108 . Arbiter  128  can employ the control signals  134 ,  136  to control the signal power levels employed by the transmitters  118 ,  122 , the timing of the transmission of the transmitters  118 ,  122 , the transmission modes employed by the transmitters  118 ,  122 , the reception modes employed by the receivers  116 ,  120 , and the like. 
       FIG. 2  shows a process  200  for the communication system  100  of  FIG. 1  according to an embodiment that considers the signal power levels of LTE transmission and WiFi reception. Although in the described embodiments the elements of the process  200  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the process  200  can be executed in a different order, concurrently, and the like. Also some elements of the process  200  may not be performed, and may not be executed immediately after each other. 
     Referring to  FIG. 2 , at  202 , the arbiter  128  determines whether the signal power level of the LTE signals  126  transmitted by the LTE transmitter  122  is less than a predetermined LTE Tx signal power threshold. If yes at  202 , then at  204 , the arbiter  128  determines whether the signal power level of the WiFi signals  124  received by the WiFi receiver  116  is greater than a predetermined WiFi Rx signal power threshold. If yes at  204 , then at  206 , the arbiter  128  allows the LTE transmitter  122  to transmit the LTE signals  126  while the WiFi receiver  116  receives the WiFi signals  124 . 
     If no at  202  or  204 , then at  208 , the arbiter  128  performs arbitration. In some cases, the arbitration involves stopping the transmission of the LTE signals  126  by the LTE transmitter  122 . In other embodiments, the arbitration involves other techniques. 
     In some embodiments, arbitration involves a comparison of the priorities of the LTE signals  126  transmitted by the LTE transmitter  122  and the WiFi signals  124  received by the WiFi receiver  116 . For example, if the priority of the traffic carried by the WiFi signals  124  is greater than the priority of the traffic carried by the LTE signals  126 , then the arbiter  128  stops the transmission of the LTE signals  126  by the LTE transmitter  122 . Conversely, if the priority of the traffic carried by the WiFi signals  124  is less than the priority of the traffic carried by the LTE signals  126 , then the arbiter  128  stops the reception of the WiFi signals  124  by the WiFi receiver  116 . 
     In some embodiments, instead of stopping the transmission of the LTE signals  126  by the LTE transmitter  122  or stopping the reception of the WiFi signals  124  by the WiFi receiver  116 , the arbiter  128  reduces the signal power level of the LTE signals  126  transmitted by the LTE transmitter  122 , or changes the transmit mode of the LTE transmitter  122 , or both. The transmit modes can include modulation and coding schemes (MCS), multiple-input and multiple-output (MIMO) ranks, and the like. In some embodiments, the transmit mode selection is based on the signal power level of the LTE signals  126  transmitted by the LTE transmitter  122 . For example, the arbiter can reduce the signal power level and MCS of the LTE signals  126  transmitted by the LTE transmitter  122  such that the resulting signal power level is less than the predetermined LTE Tx signal power threshold. 
     In some embodiments, the arbiter  128  changes the receive mode of the WiFi receiver  116  instead of, or in addition to, the above actions. For example, if the scheduled WiFi receive MCS is 16QAM (quadrature amplitude modulation), the arbiter  128  can reduce the WiFi receive MCS to QPSK (quadrature phase-shift keying). 
       FIG. 3  shows a process  300  for the communication system  100  of  FIG. 1  according to an embodiment that considers the signal power levels of WiFi transmission and LTE reception. Although in the described embodiments the elements of the process  300  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the process  300  can be executed in a different order, concurrently, and the like. Also some elements of the process  300  may not be performed, and may not be executed immediately after each other. 
     Referring to  FIG. 3 , at  302 , the arbiter  128  determines whether the signal power level of the WiFi signals  124  transmitted by the WiFi transmitter  118  is less than a predetermined WiFi Tx signal power threshold. If yes at  302 , then at  304 , the arbiter  128  determines whether the signal power level of the LTE signals  126  received by the LTE receiver  120  is greater than a predetermined LTE Rx signal power threshold. If yes at  304 , then at  306 , the arbiter  128  allows the WiFi transmitter  118  to transmit the WiFi signals  124  while the LTE receiver  120  receives the LTE signals  126 . 
     If no at  302  or  304 , then at  308 , the arbiter  128  performs arbitration. In some cases, the arbitration involves stopping the transmission of the WiFi signals  124  by the WiFi transmitter  118 . In other embodiments, the arbitration involves other techniques. 
     In some embodiments, arbitration involves a comparison of the priorities of the WiFi signals  124  transmitted by the WiFi transmitter  118  and the LTE signals  126  received by the LTE receiver  120 . For example, if the priority of the traffic carried by the LTE signals  126  is greater than the priority of the traffic carried by WiFi signals  124 , then arbiter  128  stops the transmission of the WiFi signals  124  by the WiFi transmitter  118 . Conversely, if the priority of the traffic carried by LTE signals  126  is less than the priority of the traffic carried by WiFi signals  124 , then the arbiter  128  stops the reception of the LTE signals  126  by the LTE receiver  120 . 
     In some embodiments, instead of stopping the transmission of the WiFi signals  124  by the WiFi transmitter  118  or stopping the reception of the LTE signals  126  by the LTE receiver  120 , the arbiter  128  reduces the signal power level of the WiFi signals  124  transmitted by the WiFi transmitter  118 , or changes the transmit mode of the WiFi transmitter  118 , or both. The transmit modes can include MCS, MIMO ranks, and the like. In some embodiments, the transmit mode selection is based on the signal power level of the WiFi signals  124  transmitted by the WiFi transmitter  118 . For example, the arbiter can reduce the signal power level and MCS of the WiFi signals  124  transmitted by the WiFi transmitter  118  such that the resulting signal power level is less than the predetermined WiFi Tx signal power threshold. In some embodiments, the arbiter  128  changes the receive mode of the LTE receiver  120 , either instead of, or in addition to, the above actions. 
       FIG. 4  shows a process  400  for the communication system  100  of  FIG. 1  according to an embodiment that considers the signal power level of LTE transmission, but not the signal power level of WiFi reception. Although in the described embodiments the elements of the process  400  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the process  400  can be executed in a different order, concurrently, and the like. Also some elements of the process  400  may not be performed, and may not be executed immediately after each other. 
     Referring to  FIG. 4 , at  402 , the arbiter  128  determines whether the signal power level of the LTE signals  126  transmitted by the LTE transmitter  122  is less than a predetermined LTE Tx signal power threshold. If yes at  402 , then at  404 , the arbiter  128  allows the LTE transmitter  122  to transmit the LTE signals  126  while the WiFi receiver  116  receives the WiFi signals  124 . If no at  402 , then at  406 , the arbiter  128  performs arbitration, for example as described above with reference to  FIG. 2 . 
       FIG. 5  shows a process  500  for the communication system  100  of  FIG. 1  according to an embodiment that considers the signal power level of WiFi transmission, but not the signal power level of LTE reception. Although in the described embodiments the elements of the process  500  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the process  500  can be executed in a different order, concurrently, and the like. Also some elements of the process  500  may not be performed, and may not be executed immediately after each other. 
     Referring to  FIG. 5 , at  502 , the arbiter  128  determines whether the signal power level of the WiFi signals  124  transmitted by the WiFi transmitter  118  is less than a predetermined WiFi Tx signal power threshold. If yes at  502 , then at  504 , the arbiter  128  allows the WiFi transmitter  118  to transmit the WiFi signals  124  while the LTE receiver  120  receives the LTE signals  126 . If no at  502 , then at  506 , the arbiter  128  performs arbitration, for example as described above with reference to  FIG. 3 . 
       FIG. 6  shows a process  600  for the communication system  100  of  FIG. 1  according to an embodiment that considers the signal power level of WiFi reception, but not the signal power level of LTE transmission. Although in the described embodiments the elements of the process  600  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the process  600  can be executed in a different order, concurrently, and the like. Also some elements of the process  600  may not be performed, and may not be executed immediately after each other. 
     Referring to  FIG. 6 , at  602 , the arbiter  128  determines whether the signal power level of the WiFi signals  124  received by the WiFi receiver  116  is greater than a predetermined WiFi Rx signal power threshold. If yes at  602 , then at  604 , the arbiter  128  allows the LTE transmitter  122  to transmit the LTE signals  126  while the WiFi receiver  116  receives the WiFi signals  124 . If no at  602 , then at  606 , the arbiter  128  performs arbitration, for example as described above with reference to  FIG. 2 . 
       FIG. 7  shows a process  700  for the communication system  100  of  FIG. 1  according to an embodiment that considers the signal power level of LTE reception, but not the signal power level of WiFi transmission. Although in the described embodiments the elements of the process  700  are presented in one arrangement, other embodiments may feature other arrangements. For example, in various embodiments, some or all of the elements of the process  700  can be executed in a different order, concurrently, and the like. Also some elements of the process  700  may not be performed, and may not be executed immediately after each other. 
     Referring to  FIG. 7 , at  702 , the arbiter  128  determines whether the signal power level of the LTE signals  126  received by the LTE receiver  120  is greater than a predetermined LTE Rx signal power threshold. If yes at  702 , then at  704 , the arbiter  128  allows the WiFi transmitter  118  to transmit the WiFi signals  124  while the LTE receiver  120  receives the LTE signals  126 . If no at  702 , then at  706 , the arbiter  128  performs arbitration, for example as described above with reference to  FIG. 3 . 
     In various embodiments, various measures of received signal power levels can be employed. If noise and interference are not addressed, then RSRP (reference signal received power for LTE) or RSSI (received signal strength indicator) can be employed. If noise and interference are also addressed, then SNR (signal-to-noise ratio), SIR (signal-to-interference ratio), SINR (signal-to-interference-and-noise ratio), or RSRQ (reference signal received quality for LTE) can be employed. Where user equipment  102  includes a MWS transceiver and multiple ISM transceivers are employed, the ISM transmit and receive signal power levels are those of either ISM transceiver, or both at the same time. 
     The signal power thresholds discussed herein, namely the LTE Tx signal power threshold, the LTE Rx signal power threshold, the WiFi Tx signal power threshold, and the WiFi Rx signal power threshold, are programmable values, and are stored in the arbiter  128 . The signal power thresholds can be selected according to various factors such as antenna isolation and band separation between LTE and ISM, ISM and LTE receiver performance and capability, and the like. In some embodiments, the signal power thresholds for one transceiver can be dynamic values, for example as a function of the signal power level of the other transceiver. 
     For example, assume that the saturation point of the LTE receiver  120  is −25 dBm, the antenna isolation between the WiFi antenna  110  and the LTE antenna  114  is 12 dB, the RF filter attenuation between the WiFi transmitter  118  and the LTE receiver is 20 dB, the attenuation due to band separation between WiFi transmitter  118  and the LTE receiver  120  is 10 dB, and the minimum SIR required for the LTE receiver  120  is 0 dB. Then the WiFi Tx threshold can be set at −25+12+20+10=17 dBm, and the LTE Rx threshold can be set at the WiFi transmit signal power level−12−20−10+0=the WiFi transmit signal power level−42 dBm. Therefore, if the WiFi transmit signal power level&lt;17 dBm, and if the LTE receive signal power level&gt;WiFi Tx power level−42 dBm, the arbiter  128  allows WiFi transmission and LTE reception at the same time. 
     Various embodiments feature one or more of the following advantages. From the viewpoint of an MWS base station, the downlink resource is saved from engaging in unsuccessful transactions resulting from potentially high interference with ISM transmissions from the user equipment  102 . Thus the downlink resource can be used for other user equipment  102  resulting in better resource utilization efficiency for the base station. From the viewpoint of ISM devices in user equipment  102 , the ISM receive resource is saved from unsuccessful receive transactions resulting from potentially high interference with MWS uplink packets. Note these advantages are achieved without changing existing 3GPP LTE standards. 
     Various embodiments of the present disclosure can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Embodiments of the present disclosure can be implemented in a computer program product tangibly embodied in a computer-readable storage device for execution by a programmable processor. The described processes can be performed by a programmable processor executing a program of instructions to perform functions by operating on input data and generating output. Embodiments of the present disclosure can be implemented in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, processors receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer includes one or more mass storage devices for storing data files. Such devices include magnetic disks, such as internal hard disks and removable disks, magneto-optical disks; optical disks, and solid-state disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits). 
     A number of implementations have been described. Nevertheless, various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.