Abstract: Devices, systems and method for enabling radio communications between a plurality of users are disclosed herein. In an embodiment, a mobile tactical device includes a radio connection interface, a first frequency converter, a frequency filter, and a second frequency converter. The radio connection interface is configured to receive a first radio communication having a mobile frequency from a mobile radio. The first frequency converter is configured to convert the mobile frequency to an intermediate frequency. The frequency filter is configured to pass or reject the intermediate frequency. The second frequency converter is configured to convert the intermediate frequency to an assigned transmission frequency for transmission of the first communication when the intermediate frequency passes the at least one frequency filter.

Abstract: A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory.

Abstract: A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory.

Abstract: A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory.

Abstract: A system and method for wireless communication between a plurality of subscriber units and a base station, the base station communicating information signals from an originating source to a destination subscriber unit over a channel at an assigned one of a plurality of frequencies using repetitive time frames, each said time frame comprising a sequence of time slots. The channel is defined as having the same one or more time slots from the sequence of time slots in one or more of the time frames. The base station includes a central processing unit capable of assigning a duration of time for the information signals being sent to the destination subscriber unit. The duration equals the duration of one or more time slots in the same frame. The central processing unit maintains a memory of which time slots of each time frame have been assigned and provides the time slot assignment, and therefore channel assignment, by consulting said memory.

Abstract: An approach for synchronizing operation of a first communications terminal with operation of a second communications terminal involves establishing a communications link between the first communications terminal and the second communications terminal, the communications link being defined by a communication standard; and synchronizing a first clock coupled to the first communications terminal with a second clock coupled to the second communications terminal by receiving a time standard signal into the first communications terminal independently of the communication standard. This approach can be implemented using a first clock; a first communications terminal coupled to the first clock; a second clock; a second communications terminal coupled to the second clock; a communications link defined by a communication standard; and a transmitter transmitting a time standard signal independently of the communication standard to the first clock and setting the first clock in response to the time standard signal.

Abstract: An approach for synchronizing operation of a first communications terminal with operation of a second communications terminal involves establishing a communications link between the first communications terminal and the second communications terminal, the communications link being defined by a communication standard; and synchronizing a first clock coupled to the first communications terminal with a second clock coupled to the second communications terminal by receiving a time standard signal into the first communications terminal independently of the communication standard. This approach can be implemented using a first clock; a first communications terminal coupled to the first clock; a second clock; a second communications terminal coupled to the second clock; a communications link defined by a communication standard; and a transmitter transmitting a time standard signal independently of the communication standard to the first clock and setting the first clock in response to the time standard signal.

Abstract: An approach for synchronizing operation of a first communications terminal with operation of a second communications terminal involves establishing a communications link between the first communications terminal and the second communications terminal, the communications link being defined by a communication standard; and synchronizing a first clock coupled to the first communications terminal with a second clock coupled to the second communications terminal by receiving a time standard signal into the first communications terminal independently of the communication standard. This approach can be implemented using a first clock; a first communications terminal coupled to the first clock; a second clock; a second communications terminal coupled to the second clock; a communications link defined by a communication standard; and a transmitter transmitting a time standard signal independently of the communication standard to the first clock and setting the first clock in response to the time standard signal.

Abstract: Control functions are integrated into the digital signal processing (DSP) chip functioning as the central processor unit (CPU) for the subscriber's cellular telephone unit, eliminating the microcontroller and other support chips. The integration provided is not a physical integration combining the DSP and microcontroller chips into a single chip architecture, but rather a logical (i.e., software) integration. A real time preemptive executive controls the execution of the different functions and the messaging between them. The amount of code that has to run on the DSP chip acting as the CPU is larger than the address space of the DSP chip, so the code memory is divided into banks with only one bank being activated at a time. It is the job of the real time executive to activate the banks as required to control the various functions.

Abstract: A communication system that communicates between a base station and a mobile station over a wireless rf channel. The communication system uses a novel protocol for transmitting a data frame in which an 8-bit data byte is divided into two 4-bit data nibbles. Each data nibble is assigned a 4-bit sequence number to form a transmission byte. By determining the sequence number of any transmission byte or series of transmission bytes, the beginning and the end of a data frame can be determined. A CRC check indicates when a data frame has been received successfully. The protocol does not require the use of unique start-of-frame (SOF) and end of-frame (EOF) characters. Also, the system implements a majority vote algorithm that collects data from successively transmitted copies of a given data frame and performs a majority vote to determine a mostly likely received data pattern. The protocol allows the system to achieve an improvement analogous to a 1.5 to 2.

Abstract: A multisubscriber unit is disclosed for use of in a digital cellular communication system to communicate with a base transceiver station and eventually to switched telephone network. The multisubscriber unit connects to a plurality of individual subscriber telephones. It includes a plurality of upconverters, modulators, downconverters, demodulators speech compressors, speech decompressors, and voice activity detectors that are assigned to a subscriber telephone upon detection of an off hook signal from the telephone. Preferably, upon the detection of data to be transmitted, to channel allocation is requested from a pool of time division multiple access channels in a digital speech interpolation pool.

Abstract: A digital cellular communication system in which fixed subscribers and mobile subscribers share base transceiver stations, base station controllers and mobile switching centers to communicate with the switched telephone network. Mobile subscribers communicate using any cellular radio protocol, while the fixed subscribers communicate via a multi-subscriber unit (MSU) using the inventive air interface. The MSU system uses digital speech interpolation to transmit speech spurts between subscribers and the switched telephone network. Preferably, time division multiple access channels in a digital speech interpolation pool are allocated and deallocated on a speech spurt basis.

Abstract: Cumulative timers are used in a cellular telephone to record total mobile "ON" time and total transmitter "ON" time. These "ON" times are periodically stored in long term nonvolatile memory. The period is chosen such that a time-limited number of write cycles of the nonvolatile memory are not exceeded over the life of the dual mode subscriber unit. As a consequence of utilizing periodic updates, rather than power-up event driven updates, solves this problem of the limited lifetimes of the nonvolatile memory device is solved. The use of the cumulative timers and its related computational method in a mobile telephone permits factory personnel to calculate actual mean time between failure data based upon customer returns. Timer information provided by the cumulative timers and computational method may also be used to indicate warranty fraud.