Temperature monitoring cable

A portable communication system (100) comprises a portable radio (102) and a radio accessory (106) coupled through an interface cable (108). The interface cable (108) provides an electronic interface for remote access to radio functions at the radio accessory (106). The interface cable (108) further provides a temperature sensor (110) integrated therein for monitoring environmental conditions external to the portable communication system. The portable communication system (100) generates user notifications indicating extreme temperature conditions. Notifications of extreme temperature conditions may also transmitted from the portable communication system (100) to other radios, such as a land mobile radio (120), dispatch center (130), or other radio (140) operating within a communications network.

FIELD OF THE DISCLOSURE

The present invention relates to portable communication systems, and more particularly to portable communication systems operating under adverse temperature conditions in a public safety environment.

BACKGROUND

In today's public safety environment, a portable communication system typically utilizes a portable two-way radio in conjunction with a radio accessory, such as a remote speaker microphone, headset or other wired accessory. Such accessories are typically coupled to the radio via an interface cable to provide remote access to radio features, such as speaker, microphone and push-to-talk (PTT) features. These portable communication systems are often used under adverse temperature conditions, such as encountered in fire rescue, where excessive heat may cause damage to the devices. When used in a fire rescue environment, the radio accessory and interface cable tend to be more susceptible to heat damage than the radio, because the accessory and cable are typically worn externally, while the radio tends to be worn beneath protective clothing, such as a turncoat. Wearing the protective clothing may also leave the user unaware of the surrounding temperature. Maintaining communications amongst rescue personnel is extremely important in terms of physical safety of the user and proper operation of the radio devices. The ability to provide early detection and warning of undesirable temperature conditions would thus improve user safety and minimize damage to the portable system.

Accordingly, it would be desirable to have a portable communication system for operation under adverse temperature conditions.

DETAILED DESCRIPTION

Briefly, there is provided herein an improved portable communication system formed of a portable radio and radio accessory coupled through a cable. In accordance with the various embodiments of the disclosure, a temperature sensor is integrated as part of the cable to add temperature monitoring capability of the external environment. Embedding the temperature sensor within the cable's strain relief or collar, which is worn externally, allows for a more accurate temperature reading than placement in the radio which is often worn beneath a rescuer's turncoat. The cable-based sensor is multiplexed onto existing communication lines so that no changes are needed to the radio accessory. The ability to detect accurate extreme temperature thresholds is extremely beneficial to user safety, minimizing physical damage to the system and maintaining communications.

FIG. 1is a portable communication system100formed in accordance with various embodiments. Portable communication system100comprises a portable radio102powered by a battery104coupled to a radio accessory106by interface cable108. The portable radio102and battery104provide data and power to the radio accessory106via the accessory interface cable108. The portable radio102provides two-way radio communication using a radio controller, transceiver, and antenna as understood to be known in the art of two-way radio communication. The radio accessory106may comprise a remote speaker microphone (RSM), headset or other radio accessory which provides remote access to certain radio interface features, such as speaker, microphone and push-to-talk (PTT) features.

The interface cable108comprises a plurality of wires wrapped in insulation having a strain relief118at one end and a radio universal accessory interface (UAI)128at the other end. The interface cable108provides an electrical communication interface between the portable radio102and radio accessory106. In accordance with the various embodiments, a temperature sensor110is integrated as part of the cable to add temperature monitoring capability of the external environment. Embedding the temperature sensor110within the cable's strain relief118or collar114, facilitates exposure of the sensor to the external environment without adding external modules or taking up additional space at the radio accessory106. Exposure of the cable-based sensor110to the external environment allows for a more accurate temperature reading than placement in the radio which is often worn beneath a rescuer's turncoat.

The cable temperature is measured as a means of environmental monitoring to protect the health and safety of the user in extreme environments. The temperature sensor110is monitored by the portable radio102, and in response to predetermined exposure thresholds being exceeded, the radio sends a thermal emergency indicator to the user and also transmits an emergency declaration signal to another radio, such as a land mobile radio (LMR)120, a dispatch center130, another portable radio140, and/or other radios operating within a communications network. For the purposes of this application other radios receiving the emergency declaration signal may be any portable, mobile/vehicular, or stationary communication device capable of receiving a radio frequency (RF) signal. The thermal emergency condition is thus identified by the portable radio102and transmitted directly by the portable radio102to other radios without any involvement from the radio accessory106or dependence on the use position of the radio accessory. The thermal emergency indicator to the user can take the form of a display message on an accessory display116of the radio accessory106, an audible alert at a speaker of the radio accessory106, vibration alert at the radio accessory106, and/or a light emitting diode (LED)132at the radio accessory106. The thermal emergency indicator to the user can also take place at the portable radio102in the form of a display message on a radio display124of the portable radio102, an audible alert at a radio speaker122of the portable radio102, a vibration alert at the portable radio, and/or a light emitting diode (LED)134at the portable radio102. The display alerts, LED alerts, audible alerts, and vibration alerts are all examples of user interface outputs of the portable devices. Notifications of extreme temperature conditions can thus be generated locally at one or more of the portable radio and/or RSM, as well as be transmitted to other radios. Hence, the portable communication system100is configurable to allow for various types of alerts and alert locations; however the transmission control of the alerts remains with the portable radio102.

Different temperature thresholds can be set to trigger a thermal warning notification. For example, a first temperature threshold can be set for temperatures associated with being harmful to a human body, and a second temperature threshold can be set for temperatures associated with damage to the product or certain parts of the product. Thresholds indicating shutdown of different radio functions can be set. The portable radio102utilizes a time-temperature exposure metric to declare a temperature emergency and flag the portable radio102as to the potential compromised thermal condition. The tripped notifications for the various thresholds can be sent to the user. For example, the different thresholds can be indicated by different warning messages on the radio accessory display116and or portable radio display124, such as or “THERMAL ALERT 1,” “THERMAL ALERT 2,” THERMAL ALERT 3” to provide an indication of changes in the thermal condition to which the cable-based sensor110is being exposed. Likewise, the audible alerts from the speaker126of the radio accessory106or the radio speaker122of the portable radio can send different audio messages, for example: “THERMAL ALERT 1,” “THERMAL ALERT 2,” THERMAL ALERT 3.” The LED132of the radio accessory106or the LED134of the portable radio102can illuminate in different blinking patterns and/or colors for the various thermal exposure thresholds.

Integration of the temperature sensor110within the strain relief118or collar114of the interface cable108is advantageous in terms of space and providing a seamless, non-cluttered, presentation to the user, and further ensures accurate temperature measurements of the external environment since the radio accessory106tends to be worn outside of clothing. However, if an application warrants the use of additional space, then an alternative embodiment is shown in dashed lines as temperature sensor112, where the sensor is moved further down the cable. This placement provides an alternate form factor, however as long as the sensor112is exposed to the external environment, the portable communication system100still accomplishes the operable aspects discussed previously.

FIG. 2shows a block diagram200for the accessory interface cable108coupled between portable radio102and the radio accessory106, shown here as remote speaker microphone (RSM)106. Portable radio102comprises a radio controller202, a memory204and a transceiver206for two-way radio communication. The portable radio102interfaces with the cable108via the universal accessory interface (UAI)128. The strain relief118and collar114of cable108interface with the RSM106. The RSM106provides remote access to certain radio features, for example speaker, microphone and push-to-talk (PTT) features. The RSM106may optionally comprise a controller208, however some of the embodiments of the disclosure may be supported without requiring the controller208in the RSM106. The RSM106further comprises a configuration memory210. The configuration memory210is a device that provides an additional memory for storing information pertaining to the accessory such as identification ID, accessory type, and port configuration information. The configuration memory210is preferably a single-wire serial memory integrated circuit (IC) providing non-volatile storage and operating as a read-only device, which can only be read by the portable radio102. In other embodiments, the configuration memory210may comprise a multi-wire configuration memory device. The operation of the configuration memory210is independent of the RSM106.

A wired interface214runs through interface cable108providing interface lines for speaker216, microphone218, universal serial bus (USB)220, voltage bus (Vbus)222, ground (GND)224, and accessory configuration communication bus (Accy Config Bus)226. The universal serial bus (USB)220is only used in applications involving a controller208within the RSM106, and is not required for all of the embodiments. For the preferred single-wire applications, the accessory configuration communication bus226comprises a single-wire bus utilized in conjunction with a single-wire memory configuration device. For multi-wire applications, the accessory configuration communication bus226comprises a multi-wire bus utilized in conjunction with a multi-wire memory configuration device.

In accordance with the various embodiments, the cable-based sensor110is advantageously multiplexed onto existing communication lines between the portable radio102and the RSM106, so that no changes to the radio interface or RSM head are required to support the enhanced cable. The Vbus222, GND224and accessory configuration communication bus (Accy Config Bus)226preferably operate as part of the universal accessory interface (UAI) utilizing single-wire technology. The addition of the temperature sensor110does not interfere with the readout of the accessory's configuration memory210, which is stored in an additional memory IC also connected to the single-wire interface. While the single-wire embodiment is a preferred embodiment in terms of space savings, other non-single wire embodiments can be implemented and will be discussed further on.

The basis of single-wire technology is a serial protocol using a single data line plus ground reference for communication. A single-wire master initiates and controls the communication with one or more single-wire slave devices over single data line. Each single-wire slave device has a unique, unalterable, factory-programmed, 64-bit ID (identification number), which serves as device address on the single-wire bus. The 8-bit family code, a subset of the 64-bit ID, identifies the device type and functionality. Examples of architectures for interfacing a radio with an accessory and for self-configuring an accessory device using single-wire technology may be found for example in U.S. Pat. No. 7,424,312, assigned Motorola Solutions, Inc. which is herein incorporated by reference. The universal accessory interface (UAI)128on the portable radio102provides a physical and electrical interface to the configuration memory210for transferring configuration data from the portable radio102to the RSM106.

Many single-wire devices have no pin for power supply; they take their energy from the single-wire bus (parasitic supply). However, in the embodiment shown inFIG. 2, the temperature sensor110is shown optionally supplied by Vbus222. In accordance with the various embodiments, the temperature sensor110comprises a single-wire temperature sensor attached in parallel across the accessory configuration communication bus226and ground (GND)224, wherein the accessory configuration communication bus runs a single wire interface protocol between the radio controller202and the accessory's configuration memory210. Thus, the same single data line (accessory configuration communication bus226) is accessed by both the temperature sensor110and the configuration memory210.

In accordance with the various embodiments, the external temperature is monitored in a multiplexed manner Temperature readings are stored within the memory204of the portable radio102. Upon determining that the temperature has exceeded one or more predetermined thresholds, the portable radio102sends user notifications to the radio's display, and the RSM's display. The user notification to the RSM display would be sent, for example, from the portable radio102over the USB220to the RSM106. Other notifications, such as audible alerts, vibrational alerts, and LED alerts may also be used.

In operation, the portable radio102periodically polls the cable based temperature sensor110at accessory configuration communication bus226and the temperature reading is compared to a predetermined exposure threshold stored in the portable radio's memory204. The polling acquires a plurality of temperature readings, and the exposure threshold is based on, for example how long a user can withstand a certain temperature environment without bodily harm and/or how long the equipment can continue to operate. When the exposure threshold is exceeded, the portable radio102sets a compromised bit. When the compromised bit is set, the portable radio102flags a compromised condition in, for example flash memory. The notification of a thermal emergency is transmitted to a dispatch center130and/or other radios120via the radio network. Reporting the compromised condition to the user is accomplished by triggering a message on the display of the radio and/or RSM106via USB220. Other notifications, such as audible alerts, vibrational alerts, and LED alerts may also be used.

Referring toFIG. 3, there is provided a flowchart for a method300for monitoring temperature conditions using the portable communication system ofFIG. 1in accordance with the various embodiments. The method300begins at302by attaching the radio accessory to the portable radio, and performing an accessory configuration scan at304. During the configuration scan, the radio detects all the devices on the single wire bus (accessory configuration communication bus226), and in accordance with the various embodiments detecting the temperature sensor110and the configuration memory IC210. The universal accessory interface (UAI) is then configured at306based on the detected elements. If a temperature sensor is not detected at308, then the system checks for accessory detachment at310, and when such detachment is detected the method ends at320. When a temperature sensor is detected at308, the method again senses for the accessory being detached at312, and if detachment is confirmed the method ends at320. If the radio accessory is still attached to the portable radio at312, the temperature sensor is read at314and the temperature is added to a temperature history list stored in the radio's memory at316. After a predetermined delay (ts) at318, the method returns to check for accessory detachment at312. Method300thus provides a basis for storing operational temperatures into a history which can be used in conjunction with the time-temperature exposure metric which is managed by the method ofFIG. 4.

Referring toFIG. 4, there is provided a flowchart of a method400for detecting extreme temperature conditions using the portable communication system ofFIG. 1in accordance with the various embodiments. The method400begins at402by checking for previous detections of extreme temperature thresholds at404. If a temperature threshold has been tripped at404, an indication of a compromised thermal condition is displayed on the radio at420as well as displayed on the accessory at422prior to ending the process at424. As mentioned previously audible alerts, vibrational alerts, and/or LED alerts may also provide user notifications of the tripped temperature condition. The check for previous trigger alerts at404allows a user to know if a radio has been previously operating within an adverse temperature environment that might have compromised system operability. The compromised thermal condition notification is retained until reset by a user input to the radio. This notification ensures the user is aware of the potential compromised condition.

If the system has not been previously tripped by a temperature extreme at404, then the process monitors for new temperature readings at406. The first reading (N1), or group of readings, is compared to a predetermined first temperature threshold (T1). The system continues to periodically monitor temperatures of the sensor, comparing the readings to different predetermined temperature thresholds at410,412, and414. A predetermined number of readings can be taken to avoid a single reading causing a false trigger. Again, different temperature thresholds can be set for different parameters and different warning levels, such as temperatures associated as being harmful to the user, and temperatures that can cause potential damage to the devices, and exposure to certain temperatures over time. If any thresholds are exceeded then a tripped notification is stored at416and transmitted to a dispatch center and/or other radios at418as well as being displayed as a display alert (and/or LED alert, audio alert, vibration alert) at the portable radio at420and/or at the radio accessory at422.

While the preferred embodiments have thus been described in terms of single-wire technology as part of space minimization and minimizing the number of interface lines, the temperature sensor110may also be implemented as a non-single wire temperature sensor, and the configuration memory210may also be embodied in other non-single wire memory devices, such as a two-wire memory device, a three-wire memory device to name a few. The accessory configuration communication bus226can provide bi-directional data and can clock signals to and from the configuration memory device210.

Accordingly, there has been provided a portable communication system having a radio accessory coupled to a portable radio through an interface cable, the cable providing temperature monitoring of the environment external to the system. Integrating the temperature sensor within part of the cable keeps the accessory easily portable and avoids having to have the user carry additional battery-powered devices. Locating a single-wire temperature sensor within the strain relief or collar of a radio accessory, for example by locating it on an interface PCB embedded in the strain relief between the high density connector and cable wire assembly, allows the temperature monitoring to take place without having to reconfigure the accessory itself. The system can advantageously provide user notifications at the radio accessory and the portable radio. The system advantageously provides triggering radio alerts that can be monitored at a dispatch or commander's station outside of the environment, such as a fire scene, over the high reliability two-way radio network thereby providing excellent coverage. The portable communication system thus improves the ability to protect the user's mission critical communications system by warning that excessive temperatures may potentially cause a portion of the communication system to fail or harm the user.