Abstract:
Systems and methods are disclosed for extending the communication range of mobile communication devices. A long-range radio device is controlled by a control application on a host smartphone. The long-range radio device provides signal paths for two different radios, one employing a long-range (LoRa) modulation format, and another employing a high data-rate encoding such as FSK. The system provides graceful degradation in data rate as radio link distance increases and received signal strength decreases. In addition to switching between radios, variable compression and buffering are used to adapt usage to supportable data rates. Voice, other audio, video, text, binary, and other data formats are supported, as also a wide range of co-resident host apps. Unidirectional and bidirectional links can be used.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit of U.S. Provisional Application No. 62/302,086, filed Mar. 1, 2016, entitled LONG-RANGE VOICE AND DATA TRANSMISSION USING LORA MODULATION AND SENSITIVITY-ENHANCING BUFFERING TECHNIQUES, and is also a Continuation-in-Part of U.S. patent application Ser. No. 15/436,405, filed Feb. 17, 2017, entitled COUPLING OF RADIO HARDWARE WITH A MOBILE DEVICE ACTING AS A SOFTWARE DEFINED RADIO, which is a Continuation of U.S. patent application Ser. No. 14/645,171, filed Mar. 11, 2015, entitled COUPLING OF RADIO HARDWARE WITH A MOBILE DEVICE ACTING AS A SOFTWARE DEFINED RADIO, which claims the benefit of U.S. Provisional Application No. 61/951,953 filed Mar. 12, 2014, entitled COUPLING OF RADIO HARDWARE WITH A MOBILE DEVICE ACTING AS A SOFTWARE DEFINED RADIO, filed Mar. 12, 2014. All of the above are incorporated herein by reference, in their entirety. 
     
    
     FIELD 
       [0002]    The present disclosure relates to device-to-device voice and data transmission and more specifically to voice over LoRa. 
       BACKGROUND 
       [0003]    The effective range of device-to-device voice and data transmission is affected by many factors including transmit power, antenna characteristics, receiver sensitivity and system cost. Range limitations define the usable coverage area for radio communications with greater range generally equating to better user experience. As the range of a radio system decreases, so too does its usability, adoption, and commercial viability. 
         [0004]    Present solutions to the problem of range limitations in wireless voice and data communications typically include increasing the transmit power, increasing the gain of the transmit and/or receive antenna, and leveraging low-noise architectures to increase receiver sensitivity. In mobile applications, increasing the gain of the antenna is not always possible due to form-factor constraints. As mobile applications are frequently power-constrained, increasing the transmit power results in perceptibly reduced battery life, to the detriment of device longevity and user experience. There are regulatory limits to the maximum allowable transmit power, so arbitrarily increasing the transmit power to achieve greater range is not considered a viable solution. 
         [0005]    Present solutions optimize singularly for range, seeking to maximize the range without consideration for how functionality can be adapted to best suit varying operating conditions. This fails to recognize that multiple operating modes can be utilized to provide the best overall user experience. Accordingly, there is a need for improved technologies to support radio communication over extended ranges and poor conditions, consistent with battery and power constraints of portable devices, and without compromising performance in favorable or intermediate conditions. 
       SUMMARY 
       [0006]    In summary, the detailed description presents innovations in the art of wireless communication to/from a mobile device and between mobile devices, providing a greatly extended communication range without compromising full-featured performance at short distances, while respecting the battery life constraints that are critical for mobile devices. 
         [0007]    In a first aspect, a long-range radio device is disclosed that provides two or more radios for uni- or bi-directional communication under varying conditions. In examples, a LoRa radio is provided for intermediate-range to long-range and low-data rate operation, and an FSK radio is provided for short- to intermediate-range and higher maximum data rates. The long-range radio device can be operated as an adjunct to another communication or computing device such as a smartphone. 
         [0008]    In a second aspect, a software control application is provided for a host device such as a smartphone to interface with and control the long-range radio device. The software control application can be embodied in a non-transitory computer-readable medium, or can be embodied in a host device such as a smartphone. The software control application is operable to interface with existing apps on the host device, a GPS or location/satnav device on the host device, a local interface such as Bluetooth. The software control application can be provided together with a encoder/decoder/compressor/decompressor subsystem for processing voice and other data. 
         [0009]    In another aspect, a system is described combining the long-range radio device, the host software control application, and other optional host modules. In a fourth aspect, a radio link is described comprising two such systems. 
         [0010]    In another aspect, methods of operation is provided including transmit-side and receive-side operation, including LoRa and FSK or other radio signaling, and including voice, other audio, video, and other data types. 
         [0011]    In another aspect, methods are provided to utilize one or more of a variety of inputs to determine and switch between operating modes of the aforementioned communication system. These inputs can include received signal strength readings, and GPS or another location-finding or satnav subsystem. Besides switching between FSK and LoRa radios, the LoRa operating mode can be controlled, and the data rate, compression parameters, and associated buffering can be controlled. 
         [0012]    The disclosed embodiments have other advantages and features which will be more readily apparent from the detailed description, the appended claims, and the accompanying figures (or drawings). A brief introduction of the figures follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The Figures and the following description relate to preferred embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of what is claimed. 
           [0014]    Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable, similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments of the disclosed system (or method) for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. 
           [0015]      FIG. 1  illustrates one embodiment of components of an example machine able to read instructions from a machine-readable medium and execute them in a processor (or controller). 
           [0016]      FIG. 2  illustrates an example system according to the disclosed technologies. 
           [0017]      FIG. 3  illustrates a relationship between distance and received signal strength. 
           [0018]      FIG. 4  illustrates a flowchart for operating methods according to the disclosed technologies. 
           [0019]      FIG. 5  is an exploded perspective view of a long range radio device able to be coupled with a mobile device according to the teachings of the present disclosure. 
           [0020]      FIG. 6  is a block diagram of a representative embodiment of the electronic functional components necessary for a long range radio system. 
           [0021]      FIG. 7  is a block diagram of an example embodiment of a dual-band radio system. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIG. 1  and the following description relate to preferred embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of the embodiments. 
         [0023]    Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable, similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. 
       CONFIGURATION OVERVIEW 
       [0024]    Embodiments of a disclosed system, method, and computer readable storage medium enable communication between mobile devices, or between a mobile device and a fixed station. In some embodiments, a control application on a smartphone controls a proximate long-range radio device supporting two radio standards, one of which is a long-range or low-power technology such as LoRa. The control application receives voice or data from an interface or app of the smartphone, and forwards the voice or data after processing to the long-range radio device for encoding and transmission to a remote radio station. 
         [0025]    In some embodiments, the remote receiving radio station is substantially similar to the transmitting station. A received radio signal is decoded and forwarded to a smartphone, where a control app processes the received signal and delivers the received signal to an app or interface on the remote smartphone, thus completing the communication path. Information can similarly be transmitted in the reverse direction from the remote station to the local station. 
         [0026]    The control app can switch between a long-range/low-power radio and higher data rate radio as one or both stations move, or conditions change for other reasons. 
       COMPUTING MACHINE ARCHITECTURE 
       [0027]      FIG. 1  is a block diagram illustrating components of an example machine able to read instructions from a machine-readable medium and execute them in a processor (or controller). Specifically,  FIG. 1  shows a diagrammatic representation of a machine in the example form of a computer system  100  within which instructions  124  (e.g., software) for causing the machine to perform any one or more of the methodologies discussed herein may be executed. In alternative embodiments, the machine operates as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine may operate in the capacity of a server machine or a client machine in a server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. 
         [0028]    The machine may be a server computer, a client computer, a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular telephone, a smartphone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions  124  (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute instructions  124  to perform any one or more of the methodologies discussed herein. 
         [0029]    The example computer system  100  includes a processor  102  (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a digital signal processor (DSP), one or more application specific integrated circuits (ASICs), one or more radio-frequency integrated circuits (RFICs), or any combination of these), a main memory  104 , and a static memory  106 , which are configured to communicate with each other via a bus  108 . The computer system  100  may further include graphics display unit  110  (e.g., a plasma display panel (PDP), a liquid crystal display (LCD), a projector, or a cathode ray tube (CRT) , a light-emitting diode display (LED), an organic light-emitting diode display (OLED), a quantum diode light-emitting diode display (QD-LED), or an electrophoretic display). The computer system  100  may also include alphanumeric input device  112  (e.g., a keyboard), a cursor control device  114  (e.g., a mouse, a trackball, a joystick, a motion sensor, or other pointing instrument), a storage unit  116 , a signal generation device  118  (e.g., a speaker), and a network interface device  820 , which also are configured to communicate via the bus  108 . 
         [0030]    The storage unit  116  includes a non-transitory machine-readable medium  122  on which is stored instructions  124  (e.g., software) embodying any one or more of the methodologies or functions described herein. The instructions  124  (e.g., software) may also reside, completely or at least partially, within the main memory  104  or within the processor  102  (e.g., within a processor&#39;s cache memory) during execution thereof by the computer system  100 , the main memory  104  and the processor  102  also constituting machine-readable media. The instructions  124  (e.g., software) may be transmitted or received over a network  126  via the network interface device  120 . 
         [0031]    While machine-readable medium  122  is shown in an example embodiment to be a single medium, the term “machine-readable medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, or associated caches and servers) able to store instructions (e.g., instructions  124 ). The term “machine-readable medium” shall also be taken to include any medium that is capable of storing instructions (e.g., instructions  124 ) for execution by the machine and that cause the machine to perform any one or more of the methodologies disclosed herein. The term “machine-readable medium” includes, but not be limited to, data repositories in the form of solid-state memories, optical media, and magnetic media. Specific examples of machine-readable media include non-volatile memory, including by way of example semiconductor memory devices (e.g., Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), and flash memory devices); magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The term computer-readable storage media does not include signals and carrier waves. The term computer-readable storage media can refer to non-transitory storage media. In addition, the term computer-readable storage media does not include communication ports. 
       LONG-RANGE VOICE AND DATA TRANSMISSION 
       [0032]    Example embodiments relate to sending (or transmitting) compressed or uncompressed voice and data using a combination of Frequency-Shift Keying (FSK), Long Range (LoRa) modulation and intelligent buffering. FSK and LoRa modems are functionally similar, but differ markedly in performance. FSK is a comparatively unencumbered modulation scheme. LoRa realizes lower maximum data rates owing to the degree to which the transmit spectrum is spread. The LoRa architecture allows a lower-cost and lower-power device in a smaller form factor to send voice and data over longer ranges. In some examples, bands near 900 MHz can be used, while in other examples, disclosed technology can be adapted for use on other frequency bands, including, but not limited to, VHF and UHF bands, or other bands such as 10 MHz-88 MHz, 88 MHz-108 MHz, 108 MHz-500 MHz, 500 MHz-900 MHz, 900 MHz-1 GHz, 1 GHz-2.4 GHz, 2.4 GHz-2.5 GHz, 2.5 GHz-5 GHz, 5 GHz-6 GHz, 6 GHz-10 GHz, or 10 GHz-100 GHz. 
         [0033]      FIG. 2  illustrates an example system  200  according to the disclosed technologies. This example embodiment includes an application  220  hosted on a smartphone  210  and operable to control system operation, and a long-range radio device  250  housing the radio system along with device subsystems to support the configuration and operation of the radio  250 . 
         [0034]    An example of a smartphone computing architecture (in part or whole) is described with  FIG. 1  and the corresponding computer system  100 . In some embodiments, certain components depicted as hosted within smartphone  210  can be incorporated within long-range radio device  250  and vice versa. Also included in smartphone  210  are a positioning subsystem  212 , a local interface  249 , and a user interface  214  comprising microphone  215 , touchscreen  217 , and speaker  219 . The positioning subsystem  212  can be a GPS block  212  as depicted, or an alternative such as GLONASS, Galileo, Beidou, Compass, Doris, IRNSS, or QZSS. One of ordinary skill will also appreciate that microphone  215  and speaker  219  can be implemented as stereo or array devices using amplifiers and transducers integrated within smartphone  210  or housed externally, for example in a headset (not shown). Similarly, touchscreen  217  can be implemented or augmented by a keypad, a keyboard, buttons, an external display including goggles or an augmented reality display, or annunciators. The smartphone  210  can host a variety of applications (“apps”)  230   a - n  that can process, generate, or receive voice or other data. Such apps can include messaging apps, phone apps, camera and imaging apps, entertainment apps, financial apps, location apps, mapping apps, medical apps, security apps, sensing apps, storage apps, video apps, or other services. Smartphone  210  also hosts compression subsystem  224 , which can include vocoder block  224  for compressing or decompressing voice or audio data, and a data de/compressor block  226  for compressing or decompressing other types of data. Compression subsystem can include a range of encoders/decoders suitable for different signal types. One of ordinary skill will appreciate that compression/decompression capabilities can additionally or alternatively be built-in to any one or more of apps  230   a - n.    
         [0035]    Turning to the long range radio device  250  in  FIG. 2 , among included device subsystems are an interface  251  to the smartphone  210 , a controller subsystem  260  incorporating a local microprocessor or microcontroller  262  and a signal strength monitor  264 , a transceiver subsystem including modems  281  and  285 , and a power subsystem  270  incorporating a battery  272 , battery management circuitry  274 , and power regulation circuitry  276 . Long-range radio device  250  communicates with smartphone  210  using a dedicated connection between local interface  251  and a corresponding interface  249  on the smartphone  210 . The connection between the smartphone  210  and long-range radio device  250  may be wired or wireless and use any protocol or standard with sufficient bandwidth for transmitting voice, data and command/control instructions. In one example embodiment, a Bluetooth Classic interface is used to connect the smartphone  210  and the device  250 . 
         [0036]    In addition to the microprocessor or microcontroller  262  shown, the controller subsystem  260  can incorporate an architecture similar to architecture  100  shown in  FIG. 1 , including any one or more of the components shown in  FIG. 1 . Also shown in  FIG. 2  is a signal strength monitor  264 , which can provide an indication of received signal strength, which in turn can be used to make a determination to switch between FSK and LoRa communication. One of ordinary skill will appreciate that signal strength monitor  264  depicted as part of the controller subsystem  260  can be incorporated within transceiver subsystem  280 , or can be distributed between these two subsystems. The controller subsystem  260  receives commands and data from control application  220  via the local connection between local interfaces  249 ,  251 . Commands are acted upon and/or responded to as appropriate for each command; data is forwarded to transceiver subsystem  280  for transmission to a remote system  298 . The controller subsystem  260  forwards data received from the remote system  298  via transceiver  280  to control application  220  over the same local connection. The controller subsystem  260  also reports and responds to the control application  220  over the local connection. 
         [0037]    In addition to LoRa modem  281  and FSK modem  285 , the transceiver subsystem  280  includes transmit/receive signal chains (comprising components such as one or more of amplifiers, filters, transducers, mixers, up-converters, down-converters)  282 ,  286 , and antennae  283 ,  286 . Although the radio components are shown as separate for the LoRa and FSK radio signal paths, one of ordinary skill will appreciate that one or more components can be shared between these signal paths. For example, the modems  281 ,  285  can be fabricated on the same silicon die and can even share circuit blocks. For example, through the use of wideband or multi-band RF or microwave components, antennae or signal chain components can also be shared between LoRa or FSK signal paths. One of ordinary skill will further appreciate that the discussion above is not limited to LoRa and FSK: in embodiments using additional or alternative radio technologies or standards, all of the above considerations are applicable. 
         [0038]    Control application  220  running on the host smartphone  210  configures the operating parameters of the radio device  250 , acquires the voice or text data that is to be transmitted by a user  201 , optionally compresses it using a vocoder (voice)  226  or general-purpose compression block (data)  228 , and controls display or playback of received data and voice transmissions for the user  201 . The smartphone application  220  enables the buffering of voice and data in low-bandwidth operating modes as it has access to sufficient storage in buffer  222  to record and slowly transmit large messages. Furthermore, the smartphone control application  220  allows for changes to the vocoder  226 , data compression block  228 , protocol, and modulation schemes through configuration of application  220 , or by a software update to an application (such as the control application  220 , the compression subsystem  224 , the local interface  249 , or another module) on the smartphone  210 . 
         [0039]    Configuration of the radio device  250  can include: configuring the receive mode of the radio (e.g. frequencies used, demodulation scheme used, scanning capabilities or single frequency use, etc.); configuring the transmit mode of the radio (e.g. frequencies used, modulation scheme used, whether transmitting is allowed, etc.); determining what types of filtering are used for signal processing (both radio frequency and audio frequency and other relevant signal enhancement), determining what type of interference mode is utilized (e.g. error correction method for spread spectrum techniques, identification of cooperating radios, etc.); determining signal detection functionalities (similar to filtering, but often incorporating more complex analyses); generating power adjustment methods (e.g. adapting signal strength relevant to atmospheric conditions or proximity of the second radio communication device); determining appropriate battery mode (e.g. specifying how the radio device power subsystem  270  is managed in conjunction with the power needs of radio device  250 ); determining appropriate antenna mode (e.g. antenna selection, pre-amplification, etc.); and other configurable or controllable aspects of radio communication. 
       EXAMPLE USE OF DUAL RADIOS 
       [0040]    The system described herein provides increased voice and data range primarily through improved receiver sensitivity. Receiver sensitivity is improved relative to other radio systems by use of a LoRa modulation technique and by reduced digital data rate. The maximum bit rate of an RF channel is proportional to the bandwidth of the modulated spectrum. Spreading the spectrum enables detection at a lower signal-to-noise ratio (SNR). The sensitivity of a radio receiver is directly proportional to the minimum SNR, so as this minimum SNR decreases so too does the numerical value of sensitivity (where a lower number corresponds to better performance). 
         [0041]      FIG. 3  depicts a graph  300  showing a relationship  310  between distance (plotted on the horizontal axis in  FIG. 3 ) and received signal strength (plotted on the vertical axis). Distance represents a line-of-sight distance from a transmitter, such as remote system  298  and a receiver such as in long distance radio device  250 . The transmitter power and channel conditions are presumed to be unvarying along the curve  310 . Under some conditions, received signal power varies as 1/D 2 , where D is the abovementioned distance. Operating conditions for FSK and LoRa radios are indicated on the graph  300  as follows. FSK radio sensitivity is indicated by horizontal line  322 , and indicates the minimum signal strength required for signal reception at a specified maximum bit error rate (BER) which can be 10 −3 , 10 −6 , 10, 10 −12 , or any other value or sub-range within 10 −1 -10 −15 ; the maximum BER can be specified on the raw signal or after processing with e.g. error-correcting codes. Generally, the FSK radio can be successfully operated at signal strengths greater than or equal to the sensitivity line  322 , as indicated by the arrow “FSK.” This operating region also corresponds to distances less than or equal to a maximum FSK range shown by vertical line  324 . Similarly, LoRa radio sensitivity is indicated by horizontal line  332 , and indicates the minimum signal strength required for signal reception at a maximum bit error rate specified in similar manner as for the FSK radio. Thus, the LoRa radio can be operated at signal strengths greater than or equal to the sensitivity line  332 , as indicated by the arrow “LoRa.” This operating region also corresponds to distances less than or equal to a maximum LoRa range shown by vertical line  334 . 
         [0042]    One of ordinary skill will appreciate that higher data rates are possible for greater signal strengths; this is indicated on the graph  300  by arrow  340 . Furthermore, the sensitivity lines  322 ,  332  are also data rate dependent; sensitivity can be lowered (improved) for lower data rates as described elsewhere herein. 
         [0043]    Turning back to  FIG. 2 , the long-range radio device  250  of system  200  includes both FSK and LoRa modems. In one embodiment, the LoRa modem  281  and FSK modem  285  reside on the same silicon and are selectable at runtime. The LoRa modulation technique uses a combination of chirp spread spectrum (CSS) and direct sequence spread spectrum (DSSS) to enable reception of signals of very low signal-to-noise ratio (sub-unity). Digital data rate reductions are achieved through the use of various compression techniques or through the introduction of latency to the transmission process. One byproduct of reducing the amount of data to be sent through the use of compression is that the data can be transmitted more slowly. Reducing the amount of data allows more reliable detection of weak signals by the receiver. If the data rates are slower than the data rates for real-time voice transmission, the audio may not be played back as it is received. A buffering process is used to store the voice message on the transmitting system, transmit it slowly to the other device over the RF channel, and play it back once the entire message has been received. 
         [0044]    The disclosed technique accounts for variability in link quality caused by many factors, most notably users moving closer to, or further away from one another. Existing technologies present with a static solution conceding that the performance of the radio system is fixed by the operating environment. By including both LoRa and FSK, enhanced user experience and greater functionality is provided by adapting the modulation scheme and data rates to optimally suit current conditions. Functionality is selectively enabled or disabled based on observed operating conditions in order to provide higher performance. For example, if users are in close proximity, the users may negotiate a transition from LoRa to FSK to enable high-bandwidth data transfer, switching back to LoRa modulation when the transfer is complete. If users are near or beyond the limits of the FSK radio, operation remains on LoRa and data rates scale in inverse proportion to distance of separation. When data rates are sufficiently reduced to preclude real-time voice operation, the application transitions from real-time to buffered mode wherein latency is intentionally introduced to allow continued communication. 
         [0045]    Two methods for estimating range are used: direct observation using shared geolocation data and estimation based on received signal strength. Each of the example method may be executed on a machine, for example, the computer system  100  described in  FIG. 1 . The methods may be embodied as software. The software may be referenced as computer program code or code segments and may be comprised of one or more instructions, e.g., instructions  124 . 
         [0046]    Continuing with the method, the received signal strength is directly measurable by the radio receiver, and decreases with increasing range. Since environmental factors other than range can affect the received signal strength, the received signal strength is used as a proxy for range. Operating mode adjustments are made regardless of what specific factor affects the received signal strength. Based on the range estimation, a modulation scheme is chosen. The range thresholds used for determining modulation configuration and other radio parameters are programmable. As transmit power and other important factors directly or indirectly affecting received signal strength may vary, with temperature for example, it is desirable to be able to modify these thresholds in situ. Thus the functionality of the system is scaled in response to a changing operating environment. Although voice data, text message data, and geolocation data are disclosed herein, any data of interest that is compatible with data throughput constraints can be accommodated. 
         [0047]    Alternatively or additionally, thresholds can be implemented directly on the received signal strength. Thresholds can be implemented with hysteresis, so that a threshold (distance, or received power) for transitioning to a LoRa radio can be set to a different value than for a reverse transition to a FSK radio. 
         [0048]    The radio parameters that are configured by the smartphone application  220  include transmit power, center frequency, frequency hop sequencing, bandwidth, spreading factor, etc. The complete set of configurable parameters will be specific to each different radio integrated circuit. 
       EXAMPLE OPERATING METHOD 
       [0049]      FIG. 4  illustrates a flowchart  400  for operating methods according to the disclosed technologies. The operating flow of the system is described as follows with additional reference to  FIG. 2 . The left-hand side of flowchart  400  represents process blocks performed by control application  220 , with separate columns for audio signal flow (including voice) and data signal flow. The right-hand side of flowchart  400  represents process blocks performed by long-range radio device  250 , with separate columns for LoRa signaling and FSK signaling. Additionally, dashed line  450  separates a transmitting system (above the line  450 ) from a receiving system (below the line  450 ). In this way, flowchart  400  depicts several distinct operations flows. 
         [0050]    A user  201  speaks into the microphone  215  on the smartphone  210  (or into an attached headset, not shown) and the voice signal is digitized and received at  410  by control application  210 . The digitized voice signal is encoded and/or compressed ( 420 ) by software in the vocoder block  226  resulting in a substantial reduction in signal bandwidth. The compressed voice signal is packetized within the framework of a custom protocol for transmission ( 430 ) to the radio device. This transmission is enabled by a Bluetooth connection between local interface  249  on the smartphone  200  and corresponding local interface  251  on the radio device  250 . Upon reception at the long-range radio device  250 , the local control microprocessor  262  within the radio device  250  processes the packet according to the aforementioned protocol and relays the voice data to the radio transceiver  280  for transmission. As described herein, either a LoRa radio or an FSK radio can be used according to the operating conditions and control logic. When the LoRa radio is selected, the data is encoded ( 441 ) in a LoRa modem  281 , processed through Tx signal chain  282 , and transmitted ( 447 ) via antenna  283 . Similarly, when the FSK radio is selected, the data is encoded ( 443 ) in a LoRa modem  285 , processed through Tx signal chain  286 , and transmitted ( 449 ) via antenna  287 . 
         [0051]    The process works in reverse for the reception of voice signals. Here a remote receiving system  298  will be described having similar structure  200  as the transmitting system at which process blocks  410 - 449  are performed; one of ordinary skill will appreciate that the same reference numbers are used for description solely for purpose of illustration, and that in typical embodiments, the receiving system and the transmitting system are distinct. 
         [0052]    According to operating mode, LoRa signals are received ( 451 ) at antenna  283 , processed through Rx signal chain  282  and decoded in LoRa decoder  281  to reach controller subsystem  260  of a receiving radio device  250 . Alternatively, FSK signals are received ( 453 ) at antenna  287 , processed through Rx signal chain  286  and decoded in LoRa decoder  285  to reach the controller subsystem  260 . The local microprocessor  262  packages data or audio (including voice) received by the radio transceiver  280  and transmits ( 460 ) the packaged data to the smartphone application  220  using the Bluetooth connection between local interfaces  251  and  249 . Upon reception ( 465 ) at the smartphone, the data is processed according to the type of application data that was received. Voice data is decoded ( 470 ) using vocoder block  226  to recreate the original voice message and reproduced or played ( 490 ) out the device speaker  219  (or attached headset, not shown) for the user  201  to hear. The voice message can optionally be stored ( 480 ) on the receiving smartphone  210 . In cases where buffering is used, the buffering is implemented on the host smartphone  210  using buffer  222 . 
         [0053]    The operating flow of process blocks  410 - 490  has been described particularly with regard to a voice signal, which may also involve phone apps  230   b  or instant messaging apps  230   c  on both transmitting and receiving systems. An operating flow for other audio signals similarly follows process blocks  410 - 490 , however the audio encoding/decoding can be performed by encoders/decoders that are not voice-specific. A wide range of audio encoders/decoders can be used, following lossy standards such as AAC, MP3, SBC, or Vorbis, or following lossless standards such as ALAC, APE, FLAC, TTA, or WMAL. 
         [0054]    The operating flow of data signals is similar to that described for voice signals above. On the transmit side, the control application  220  receives a data signal at  415 , which may be sourced from any app  230   a - n,  from the operating system of smartphone  210 , or by the user&#39;s entry via touchscreen  217 , another user input device, or from an externally attached storage device. At  420 , the data signal is compressed by data compressor  228 . The subsequent operating flow from process blocks  430 - 465  proceeds substantially similarly to that described above for voice signals, using either LoRa or FSK signal path according to the configuration and operating conditions. At process block  475 , on a receiver smartphone  210 , the data signal is decoded by decompressor  228 , following which the data signal can be optionally stored ( 485 ) or reproduced ( 495 ). Reproduction of the data signal can take the form of text or graphical display on e.g. touchscreen  217 . In some embodiments or configurations, the received data can be stored at  485  without decompression. 
         [0055]    Geolocation data is provided by the GPS block  212  included in the operating system software. Voice encoding and compression is implemented in software or firmware, by vocoder block  226 . In one embodiment, a G.729 vocoder algorithm is used. Received text messages are stored in the smartphone application and displayed on touchscreen  217 . Received voice messages are able to be played in real-time when as they are received, and/or stored for playback later, at the user&#39;s convenience. 
       ADDITIONAL EXAMPLES 
       [0056]      FIG. 5  is an exploded illustration  500  of an exemplary long-range radio device  520  operable in conjunction with a mobile device  512 . A protective case  502  encloses components and, in some examples, can be configured to receive and releasably secure a mobile device  512 . An antenna  504  is coupled to the protective case  502 , which in certain embodiments may be fixed in an extended form from the case  502 , while in other embodiments may be collapsible to reside within the case  502  when not in use and extended when in use. In other embodiments, the antenna  504  may be incorporated entirely within the case  502 . Radio electronics or device  506  exist embedded within the case  502 , and in some embodiments, a rechargeable battery  508  may further be embedded within the case  502 . The radio electronics  506  embedded in the case  502  may include those illustrated in  FIG. 2 , for example a radio controller  260 , transceiver  280 , etc. 
         [0057]    The protective case  502  allows the radio electronics  506  to communicatively couple with the mobile device  512  as previously noted, with some embodiments using a direct connection  510  as an interface to connect the mobile device  512  and radio electronics  406 . The mobile device  512  and radio electronics  506  may be connected in a wired or a wireless configuration. In the wired configuration (illustrated in  FIG. 5 ), the interface connector  510  includes an opening through which a connection such as a USB cord or the like may be threaded, the connection corresponding to a data port of the mobile device  506 . Alternatively, the communication device  500  may include a port which connects directly with the data port of the mobile device. It should be noted that various makes and models of mobile devices  512  will have varying data port configurations, and the cases  502  and connectors  510  of the present disclosure may be configured and manufactured to accommodate those makes and models. In other embodiments, connector  510  is absent, and a long-range radio device similar to  520  is wireles sly coupled to mobile device  512 . The wireless connection may be made using Bluetooth® technology, Wi-Fi, or other technology known in the art. 
         [0058]    Thus, the complete protective case  502  is a single unit consisting of multiple assembled components which, in conjunction, allow for wireless or wired coupling of a mobile device to a long-range radio device. In some embodiments, mobile devices  512  for use with the case  502  can have unique dimensions, connection types, and connector locations, and as such each case  502  may have mobile device-specific configurations. 
         [0059]      FIG. 6  is a block diagram of a representative embodiment  600  of the electronic functional components necessary to interact with a long range radio system. An RF circuit  602  includes the circuitry necessary for long-range communication capabilities, as previously described. The RF circuit  602  interconnects to an onboard controller circuit  604  via DC power and analog signals as well as control signals, as indicated. The onboard controller circuit  604  can interconnect with voltage and power circuits  606 , also via DC power and control signals as indicated. Finally, if a rechargeable battery  608  is further connected, it is interconnected with the voltage and charge system  606 . These components are connected via the onboard controller  604  to the mobile device  610 , which manifests the software component of the long-range radio. 
         [0060]      FIG. 7  is a functional descriptive circuit diagram of one possible embodiment of a dual band long-range radio  700 , which can be a software-defined radio. Component  702  represents the transmit-receive switching and various frequency band selection capabilities of the antenna. Components  704  are representative of the various filtering, amplification, and control circuits for sending and receiving radio signals. Components  706  show two transmitter and receiver bands, A and B, of which additional bands may be used as desired. Component  708  provides the software interface point for the various control and analog/digital conversions. This control point  708  interfaces with the mobile device  710 , manifesting the software component of the long range radio system  700 . 
       ADDITIONAL FEATURES 
       [0061]    In some embodiments, two communicating stations are substantially similar; each station can be mobile, and can include a smartphone hosting a control app and having a variety of other apps and interfaces, together with a long-range radio device as described. Both stations can be capable of bidirectional communication. However, many other configurations can also be supported by the disclosed technologies. In examples, one station can be a fixed station, such as a base station, access point, or server. In examples, one station can be integrated, with control app and long-range radio integrated in a single housing. In examples, a mobile station can run its control app on a laptop, tablet, or other portable computing device, or on a computing device mounted on a vehicle. In examples, two communicating stations can be enabled for only unidirectional communication between control apps, with limited bidirectional link-layer signaling between the long-range radio units, for the purpose of negotiating connections and switching between radio standards. In examples, unidirectional signaling can be supported from a mobile station to a fixed station with no reverse communication at all: the mobile station can select between radio standards based on the distance between its location and the known location of the fixed station, while the fixed station can listen on both radio channels. 
         [0062]    In some embodiments, a mobile station according to disclosed technologies can be powered by a battery, such as lithium-ion, lithium polymer, alkaline, nickel cadmium, nickel metal hydride, or lead-acid. However, battery power is not a requirement. A mobile station can be powered by solar power, a fuel cell, a thermoelectric generator, a portable fossil fuel generator, an energy harvester, or even a small sealed transportable autonomous reactor. 
         [0063]    In some embodiments, communication between a smartphone or other host device and its associated long-range radio is performed using Bluetooth®, however other wired and wireless technologies can be used. Among wireless technologies, DECT, IEEE 802.11 (including a, b, g, n, y, ac, or ad clauses), IEEE 802.15, IrDA, Near Field Communication (NFC), Ultra Wideband, Wireless USB, or ZigBee standards can also be used. Among wired standards, Firewire, IEEE 802.3 (Ethernet family), IEEE 1901, Thunderbolt, or USB can be used. Optical technologies such as Li-Fi or IEEE 802.15.7 can also be used. 
         [0064]    In embodiments, signals may be encoded and/or decoded multiple times over the communication path from a transmitting app at a first station to a receiving app at a second station. As described herein, the control app at a transmitting station can route a speech signal to a vocoder which can encode the signal to achieve compression and bandwidth reduction. Correspondingly, at a receiving station the control app can route a received signal to a vocoder to recover the speech signal. Data signals can similarly be compressed (and decompressed) by any of a variety of data compression function blocks. Thus, baseband encoding/decoding can be performed at a station, for example by a smartphone, for the purpose of compression/decompression. In embodiments, baseband coding can additionally or alternatively provide encryption/decryption. The baseband coding functionality can be dynamically varied according to selected radio, distance, received signal strength, remaining battery life, or other parameters. 
         [0065]    As described herein, the long-range radio device can perform encoding on a signal to be transmitted according to a selected radio standard. In examples, the signal can be encoded using CSS for LoRa transmission, or using frequency-shift keying for FSK transmission. Thus, radio encoding/decoding can be performed at a long-range radio device for the purpose of modulation. In embodiments, encoding/decoding can also perform security functions, such as frequency-hopping, or signal spreading. 
         [0066]    Additional signal encoding/decoding can also be performed, for example over a Bluetooth® or other local link. 
         [0067]    In some embodiments, the location of a smartphone is obtained from a GPS module integrally incorporated within the smartphone. However, other location finders can be used with the disclosed technologies, including subsystems, modules, services, and/or auxiliary units using any satellite navigation (satnav) technologies reported herein, or other radio, celestial, inertial, or magnetic position finding technologies. 
         [0068]    The present disclosure often refers to a mobile device or cellular telephone as a smartphone. It should be understood that the term smartphone encompasses other forms of mobile computing devices. A “mobile device” is any portable device normally utilized for communication, specifically not including any device with existing capabilities using LoRa modulation, as described for example in SemTech Application Note AN1200.22 dated May 2015. Such devices may include cellular telephones or any other device operable over the cellular telephone network, tablet computers, laptop computers, music players, and any other devices which can make use of the internet (either wired or wireless, such as Wi-Fi, WiMAX, LTE, etc.), or other similar devices normally utilized for communication and can contain a microphone and speaker or equivalent, e.g. via a plug-in or connectable via wireless technologies (e.g. Bluetooth®), and also capable of executing software. An exemplary smartphone is a mobile device which allows the user to modify the functionality to personalize the set of software applications which can be executed on the mobile device. Such applications may include a World Wide Web (WWW or web) browser, camera and video recording capabilities, tracking and logging software (e.g. vehicle mileage tracking), and global positioning software for location-finding, as well as multimedia applications for watching movies or listening to music. Further, the applications may include vendor-specific content, such as restaurant reviews or television programming. Practically any type of software application may be created for use on a smartphone. 
       ADDITIONAL CONFIGURATION CONSIDERATIONS 
       [0069]    Throughout this specification, plural instances may implement components, operations, or structures described as a single instance. Although individual operations of one or more methods are illustrated and described as separate operations, one or more of the individual operations may be performed concurrently. Additionally, the operations may be performed in an order other than the order illustrated. Structures and functionality presented as separate components in example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter herein. 
         [0070]    Certain embodiments are described herein as including logic or a number of components, modules, or mechanisms. Modules may constitute either software modules (e.g., code embodied on a machine-readable medium or in a transmission signal) or hardware modules. A hardware module is tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. In example embodiments, one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware modules of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or application portion) as a hardware module that operates to perform certain operations as described herein. 
         [0071]    In various embodiments, a hardware module may be implemented mechanically or electronically, and may be configured to perform certain operations either permanently or temporarily. For example, a hardware module may comprise dedicated circuitry or logic that is permanently configured (e.g., as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC)) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (e.g., as encompassed within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. It will be appreciated that the decision to implement a hardware module mechanically, in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations. 
         [0072]    The various operations of example methods described herein may be performed, at least partially, by one or more processors (e.g., as described with  FIG. 1 ) that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Whether temporarily or permanently configured, such processors may constitute processor-implemented modules that operate to perform one or more operations or functions. The modules referred to herein may, in some example embodiments, comprise processor-implemented modules. 
         [0073]    The one or more processors may also operate to support performance of the relevant operations in a “cloud computing” environment or as a “software as a service” (SaaS). For example, at least some of the operations may be performed by a group of computers (as examples of machines including processors), these operations being accessible via a network (e.g., the Internet) and via one or more appropriate interfaces (e.g., application program interfaces (APIs).) 
         [0074]    The performance of certain of the operations may be distributed among the one or more processors, not only residing within a single machine, but deployed across a number of machines. In some example embodiments, the one or more processors or processor-implemented modules may be located in a single geographic location (e.g., within a home environment, an office environment, or a server farm). In other example embodiments, the one or more processors or processor-implemented modules may be distributed across a number of geographic locations. 
         [0075]    Some portions of this specification are presented in terms of algorithms or symbolic representations of operations on data stored as bits or binary digital signals within a machine memory (e.g., a computer memory as described with  FIG. 1 ). These algorithms or symbolic representations are examples of techniques used by those of ordinary skill in the data processing arts to convey the substance of their work to others skilled in the art. As used herein, an “algorithm” is a self-consistent sequence of operations or similar processing leading to a desired result. In this context, algorithms and operations involve physical manipulation of physical quantities. Typically, but not necessarily, such quantities may take the form of electrical, magnetic, or optical signals capable of being stored, accessed, transferred, combined, compared, or otherwise manipulated by a machine. It is convenient at times, principally for reasons of common usage, to refer to such signals using words such as “data,” “content,” “bits,” “values,” “elements,” “symbols,” “characters,” “terms,” “numbers,” “numerals,” or the like. These words, however, are merely convenient labels and are to be associated with appropriate physical quantities. 
         [0076]    Unless specifically stated otherwise, discussions herein using words such as “processing,” “computing,” “calculating,” “determining,” “presenting,” “displaying,” or the like may refer to actions or processes of a machine (e.g., a computer) that manipulates or transforms data represented as physical (e.g., electronic, magnetic, or optical) quantities within one or more memories (e.g., volatile memory, non-volatile memory, or a combination thereof), registers, or other machine components that receive, store, transmit, or display information. 
         [0077]    As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
         [0078]    Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. For example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this regard. 
         [0079]    As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). 
         [0080]    In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise. 
         [0081]    Upon reading this disclosure, those of ordinary skill in the art will appreciate still additional alternative structural and functional designs through the disclosed principles of the embodiments. Thus, while particular embodiments and applications have been illustrated and described, it is to be understood that the embodiments are not limited to the precise construction and components disclosed herein. Various modifications, changes and variations which will be apparent to those skilled in the art may be made in the arrangement, operation and details of the method and apparatus disclosed herein without departing from the spirit and scope as defined in the appended claims.