Patent Application
20170290032
A trunked communication system, such as a Land Mobile Radio (LMR) system, is one in which mobile or portable user terminals, such as mobile telephones, portable or mobile radios (herein collectively referred to as “radios”) can communicate via a network infrastructure. The network infrastructure generally includes fixed installations, for example, one or more fixed base stations and/or various sub-systems that manage and control the system. The radios operating in trunked communication systems share radio frequency (RF) communication channels (also referred to as traffic/data channels) and are configured to send and receive calls and other data on shared traffic channels. A site controller, for example a base station, manages transmissions sent from radios on free traffic channels whose availability is determined by the site controller. The site controller assigns one or more channels as the “control channel”, wherein on the control channel the site controller transmits, to the radios, system information and other data associated with the shared traffic channels.
Each radio may be configured to communicate with a group of radios (referred to herein as a talk group). For example, a radio used by a firefighter may be affiliated with a firefighter talk group and a radio used by a police officer may be affiliated with a police talk group. In some circumstances, members of a talk group may transmit location data, sensor information or other short data to other talk group members. For example, in a fire emergency scene, firefighters may want to transmit location data so that each firefighter in the firefighter talk group is aware of the locations of other firefighters in the firefighter talk group at the emergency scene. In another example, police officers in a police talk group may also want to transmit location data to other talk group members to, for example, respond faster to back-up calls. In some current implementations, each talk group is periodically assigned a downlink data channel that is used to transmit location data to talk group members. When the communication system includes a large number of talk groups, a significant number of the downlink data channels that could otherwise be used to transmit calls between radios are used to transmit location data to talk group members.
Accordingly, there is a need for an improved method and apparatus for tracking short messages of talk group members.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views, together with the detailed description below, are incorporated in and form part of the specification, and serve to further illustrate embodiments of concepts that include the claimed invention, and explain various principles and advantages of those embodiments.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
Some embodiments are directed to methods and apparatuses for tracking short messages of talk group members. A subscriber device joins a talk group and receives, via a control channel, parameters defining a plurality of assigned downlink data transmission periods associated with the talk group on a downlink short data channel. The subscriber device determines from the parameters when a next downlink short data transmission for devices in the talk group will be transmitted on the downlink short data channel. The subscriber device switches to the downlink short data channel during the next transmission period.
At or subsequent to registering with system 100, each of radios 102 may join one or more talk groups. For example, radios 102a-102d may join a first talk group 106a, radios 102e-102i may join a second talk group 106b, radios 102j-102m may join a third talk group 106c; and radios 102o-102x may join a fourth talk group 106d. Radios 102 may transmit, for example, on a periodic basis or during a specified period, short data including, for example, location data, telemetry data and/or biometrics data to controller 104. For example, each radio may obtain its current location from a global positioning satellite (GPS) and/or via a triangulation process and transmit the obtained location data to controller 104 on a periodic basis or during a specified period.
Subsequent to receiving short data transmitted from radios 102a-102o, controller 104 may aggregate the received short data by talk group 106. For instance, controller may aggregate the short data received from radios 102a-102d in first talk group 106a, controller may aggregate the short data received from radios 102e-102i in second talk group 106b, controller may aggregate the short data received from radios 102j-102m in third talk group 106c, and controller may aggregate the short data received from radios 102o-102x in fourth talk group 106d. Controller 104 is thereafter configured to transmit the aggregated short data to radios 102 during transmission periods assigned to each talk group 106. For instance, controller 104 may send the location data associated with radios 102a-102d during a transmission period assigned to first talk group 106a on the short data channel; controller 104 may send the location data associated with radios 102e-102i during a transmission period assigned to second talk group 106b on the short data channel; controller 104 may send the location data associated with radios 102j-102m during a transmission period assigned to third talk group 106c on the short data channel; and controller 104 may send the location data associated with radios 102o-102x during a transmission period assigned to fourth talk group 106d on the short data channel. Controller 104 may transmit the location data for each talk group in a transmission period assigned to the talk group on the shared and dedicated downlink short data channel according to, for example, a Time Division Multiple Access (TDMA) access scheme. Each time slot/transmission period may have a fixed span of, for example, 200 ms.
At or subsequent to registering with system 100, each radio 102 is provided information about a transmission period (for example, time slot information) on the short data channel for its associated talk group(s). Each radio 102 may also receive a mapping table that maps each talk group to a specific transmission period on the short data channel. The mapping table may be modified based on changes to the number of talk groups, based on additions of new talk groups, based on removal of existing talk groups, based on additions of radios to existing talk group(s), or for some other reason. In an embodiment, controller 104 may transmit a talk group Trunked Signaling Block (TSBK) message (also referred to herein as a location control message or a control message) on a control channel to update information in the mapping table. The location control message may include parameters defining a plurality of assigned downlink data transmission periods associated with talk groups on the short data channel.
Controller 104 uses the aggregated location data, among other information, to configure the parameters of the location control message. Based on the parameters transmitted in the location control message, each radio 102 is configured to determine a specific downlink data transmission period when controller 104 is to transmit location data for each talk group. Therefore, the location control message may, for example, provide time slot synchronization information so that each radio 102 may switch to the short data channel during a transmission period when controller 104 is configured to send short data for the talk group to which the radio belongs.
Location control message 200 may be broadcast periodically or intermittently on the control channel. Location control message 200 may also be broadcasted when there is a change in the mapping table that maps each talk group to a specific transmission period on the short data channel. Subsequent to receiving location control message 200, each radio 102 uses information in location control message 200 to determine the total number of time slots on the short data channel and the span of each time slot. Using the information in total slot number field 202 and slot time span field 204, each radio 102 may calculate the time period including all time slots on the short data channel (i.e., the total number of transmission periods on the short data channel). Considering that subsequent to registering with system 100 each radio 102 is provided the time slot(s) for its associated talk group(s), when each radio 102 receives location control message 200, the radio may use the information in location control message 200 to determine when its next talk group location information is to be transmitted on the short data channel (i.e., the radio may use the information location control message 200 to determine the upcoming transmission period for its talk group).
Using the example above where there are four talk groups 106, controller 104 may broadcast the aggregated location information for radios in each talk group 106 in four corresponding time slots in each repeating block of time slots on the short data channel. For example, controller 104 may send the aggregated location information for the first talk group 106a (i.e., the talk group including radios 102a-102d) in time slot 1 of a repeating block of time slots; controller 104 may send the aggregated location information for the second talk group 106b (i.e., the talk group including radios 102e-102i) in time slot 2 of the repeating block of time slots; controller 104 may send the aggregated location information for the third talk group 106c (i.e., the talk group including radios 102j-102m) in time slot 3 of the repeating block of time slots; and controller 104 may send the aggregated location information for the fourth talk group 106d (i.e., the talk group including radios 102o-102x) in time slot 4 of the repeating block of time slots.
In an embodiment, each radio 102 may use the following formula to calculate a beginning of an upcoming transmission period on the short data channel when the aggregated location information for its talk group members is to be transmitted:
a beginning of an upcoming transmission period=(a target time slot−a current time slot−1)*a slot time span+a next time slot gap,
The processor 503 may include a code read-only memory (ROM) 512 for storing data for initializing system components of radio 500. The processor 503 may further include a microprocessor 513 coupled, by the common data and address bus 517, to one or more memory devices, such as a read only memory (ROM) 514, a random access memory (RAM) 504, and/or a static memory 516. One or more of ROM 514, RAM 504 and flash memory 516 may be included as part of processor 503 or may be separate from, and coupled to, the processor 503.
Communications unit 502 may include an RF interface 509 configurable to communicate with network components and other user equipment within its communication range. Communications unit 502 may include one or more broadband and/or narrowband transceivers 508, such as an Long Term Evolution (LTE) transceiver, a Third Generation (3G) (3GGP or 3GGP2) transceiver, an Association of Public Safety Communication Officials (APCO) Project 25 (P25) transceiver, a Digital Mobile Radio (DMR) transceiver, a Terrestrial Trunked Radio (TETRA) transceiver, a WiMAX transceiver perhaps operating in accordance with an IEEE 802.16 standard, and/or other similar type of wireless transceiver configurable to communicate via a wireless network for infrastructure communications. Communications unit 502 may also include one or more local area network or personal area network transceivers such as Wi-Fi transceiver perhaps operating in accordance with an IEEE 802.11 standard (e.g., 802.11a, 802.11b, 802.11g), or a Bluetooth transceiver. The transceivers may be coupled to a combined modulator/demodulator 510. The one or more memory devices 512, 514 and 516 are configured to store non-transitory computer-executable instructions to perform a set of functions such as one or more of the steps set forth in
Communications unit 702 may include a wired or wireless input/output I/O interface 709 configurable to communicate with network components and other user equipment. Communications unit 702 may include one or more broadband and/or narrowband transceivers 708, such as an Long Term Evolution (LTE) transceiver, a Third Generation (3G) (3GGP or 3GGP2) transceiver, an Association of Public Safety Communication Officials (APCO) Project 25 (P25) transceiver, a Digital Mobile Radio (DMR) transceiver, a Terrestrial Trunked Radio (TETRA) transceiver, a WiMAX transceiver perhaps operating in accordance with an IEEE 802.16 standard, and/or other similar type of wireless transceiver configurable to communicate via a wireless network for infrastructure communications. Communications unit 702 may also include one or more local area network or personal area network transceivers such as Wi-Fi transceiver perhaps operating in accordance with an IEEE 802.11 standard (e.g., 802.11a, 802.11b, 802.11g), or a Bluetooth transceiver. Still further, the communication unit 702 may additionally or alternatively include one or more wireline transceivers 708, such as an Ethernet transceiver, a Universal Serial Bus (USB) transceiver, or similar transceiver configurable to communicate via a twisted pair wire, a coaxial cable, a fiber-optic link or a similar physical connection to a wireline network. The transceivers may be coupled to a combined modulator/demodulator 710. The one or more memory devices 712, 714 and 716 are configured to store non-transitory computer-executable instructions to perform a set of functions such as one or more of the steps set forth in
In the foregoing specification, specific embodiments have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present teachings.
The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
Moreover in this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a”, “has . . . a”, “includes . . . a”, “contains . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element. The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein. The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%. The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically. A device or structure that is “configured” in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
It will be appreciated that some embodiments may be comprised of one or more generic or specialized processors (or “processing devices”) such as microprocessors, digital signal processors, customized processors and field programmable gate arrays (FPGAs) and unique stored program instructions (including both software and firmware) that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of the method and/or apparatus described herein. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used.
Moreover, an embodiment can be implemented as a computer-readable storage medium having computer readable code stored thereon for programming a computer (e.g., comprising a processor) to perform a method as described and claimed herein. Examples of such computer-readable storage mediums include, but are not limited to, a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a ROM (Read Only Memory), a PROM (Programmable Read Only Memory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM (Electrically Erasable Programmable Read Only Memory) and a Flash memory. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2014/090966 | 11/13/2014 | WO | 00 |
