Abstract: A frequency hopping spread spectrum telecommunication system is provided, which selects carrier frequencies based on the number of active slots. The duration that carriers have been employed is then based on the number of active slots (401, 402), rather than the number of frames (22). Thus, non-interfered with carriers can be used more often than interfered with carriers, thereby improving voice quality.

Abstract: A method for avoiding interference in a wireless telecommunication system is provided. The method includes providing communication between a first and second component at an initial frequency. A plurality of successive line quality indicators is determined at a line quality monitor of the first component. Consecutive line quality indicators are summed over a predetermined time to determine a slow hop count. A determination is made as to whether the slow hop count is greater than a slow hop threshold. A determination is made as to whether to provide communication with the first component at a second frequency when the slow hop count is greater than the slow hop threshold. This determination is based on a power level of the second component and a communication strength received from the second component at the first component. A signal is communicated from the first component to the second component requesting the second component to provide communication at the second frequency.

Abstract: A method and system for the wire-free transmission of data between a mobile unit and a fixed station in time slots on one of a number of carrier frequencies with fixed station and the mobile unit each respectively include both a device for outputting a predetermined sequence which prescribes the carrier frequencies of the time slots, the carrier frequencies of two successive time slots being different, and an RF module for transmitting the data in time slots, the carrier frequencies of the time slots each being prescribed by the predetermined frequency of the output device.

Abstract: Providing an audio broadcast for a TDMA system. During a single time slot, an audio message is broadcast from a base art and received at a number of portable arts. An audio broadcast command is generated by designating the single time slot and then transmitted to the plurality of portable parts. An additional portable part transmits a broadcast origination signal and the audio message to the base part which transmits the audio broadcast command to the portable parts. by assigning a time slot other than the designated time slot to a portable part, the portable part does not broadcast audio messages during the designated time slot. More than three receiving time slots and more than three sending time slots are divided out for the base art that includes the designated time slot. The audio broadcast command is transmitted during at least two of the more than three sending time slots.

Abstract: The invention relates to a method and a device for digital data radiotransmission between a fixed station (1) and at least one mobile station (2, 3) at one or several carrier frequencies (F1, F2 . . . ), wherein the data is transmitted in several time slots (Z1, Z2 . . . ) according to the time-multiplex technique. A specific amount of time is required to change from one carrier frequency to another carrier frequency using a slow-hopping HF module. The data is transmitted in an active followed by an inactive time slot during which no data is transmitted and which is sufficient for the HF module to program the frequency for the following active time slot. According to the invention, an inactive time slot is shorter than an active time slot.

Abstract: The present invention relates to a radio inter-face for a cordless small system using the 2.4 GHz ISM band. According to the present invention, a transmission system having a fixed station (1) and at least one mobile station (2, 3) is provided for this purpose, the fixed station (1) and the mobile station (2) each having devices (RF modules 4, 5) in order to transmit the data in time slots using a frequency-division multiplex method (FDMA) and a time-division multiplex method (TDMA), and with time division duplexing (TDD). As is known from DECT Standard, the data are modulated onto a carrier frequency (fx) using a GMSK modulation method. The RF modules (4, 5) in the fixed station (1) and, respectively, the mobile station (2) are in this case designed such that the carrier frequency (fx) is changed after a predetermined time period, which may correspond, for example, to the time duration of a time slot or of a transmission frame. A transmission frame in this case contains 16 time slots.

Abstract: A method and an apparatus transmits information in various carrier frequencies with frequency hopping. A table 25 with a plurality of n possible carrier frequency values fx in addresses 1 through N of the table 25 is thereby offered. Further, a sequence of random values is generated, for example in a random number generator 22, on the basis whereof a part M of the N carrier frequency values fx is read from the corresponding addresses of the table 25, whereby M?N applies. Information is subsequently transmitted in the corresponding carrier frequencies. The inventive apparatus or, respectively, the inventive method can be implemented, for example, in a mobile station and/or a base station of a mobile radiotelephone system.

Abstract: A programmable band-pass filter in a radio-frequency receiver. The band-pass filter has a bandwidth substantially covering a channel bandwidth. Once the appropriate channel in use is determined, the frequency band of the band-width filter is set to correspond to it.

Abstract: According to the invention, a mobile radio is provided for radio transmission in time-division multiplex frames, where these frames each alternatively have active time slots (Z1) in which data are transmitted, and inactive time slots (Z2) in which no data are transmitted. The time duration of the active time slots is, in this case, twice the duration of the inactive time slots. The mobile radio (1, 2) has a burst mode controller (13) which provides the time-division multiplex frame structure for transmission, and a clock preset device (18), which presets the clock rate for the burst mode controller (13). The clock rate which the clock device (18) presets for the burst mode controller (13) is twice as high during the inactive time slots (Z2) as during the active time slots (Z1).

Abstract: A system and method for call screening in a wireless telephone system. When a call is received on an answering machine (17) associated with a base part (11), the user at a portable part (12) may select a call screen button (19). The resulting signal is received at the base part (11), which then enters a broadcast mode. The incoming answering machine message is broadcast to all handsets (12, 14, 16). In a TDMA system, an audio message is broadcast from a base part (11) during a single time slot of a time division. The user at a particular portable part may then select a pick up button to pick up the call.

Abstract: The invention proposes a method and an apparatus for the radio transmission of user data, arranged in data words of a defined length, in time-division multiplex frames having active time slots in which data are transmitted and inactive time slots in which no data are transmitted. The user data are stored temporarily in a memory at a first data rate, and are read out from the memory and converted into the time-division multiplex frames at a second, greater data rate. During the time period from the beginning of an active time slot to the beginning of the subsequent active time slot, n (n=a whole number ≧1) data words of the user data are thereby respectively stored. By synchronizing the storing and the reading out of the user data, these data can be transmitted with the smallest possible delay in an arbitrarily selected time slot of the time-division multiplex frame.

Abstract: The present invention comprises a system and method for improving voice quality of cordless communications. The system comprises at least one mobile unit having circuitry for maintaining an individual communication link with a base station. The system also has logic residing in the base station for selecting a frequency to maintain the communication link, monitoring parameters relating to the quality of the frequency, and performing data correction on the frequency in response to the monitored quality of the frequency.

Abstract: The present invention is directed to a method and to a system for regulating the transmission power of a mobile station (2) of a mobile radiotelephone system in which information are transmitted in various carrier frequencies with a frequency hopping method. The fixed station (1) comprises a receiver (4) for receiving information that are transmitted from a mobile station (2). The fixed station (1) also comprises a detector (11) for detecting the transmission quality of the transmitted information. When the transmission quality is good and the information were transmitted with a high transmission power, a first message for lowering the transmission power is sent to the mobile station and, when the transmission quality is poor and the information were transmitted with a low transmission power, a second message for raising the transmission power is sent to the mobile station. The present invention serves the purpose of lowering the power consumption in a mobile station of a mobile radiotelephone system.

Abstract: A frequency downconversion receiver is provided that does not require predictive filtering for signal acquisition and synchronization. A sync block modulates a voltage-controlled oscillator (VCO) with twice the frequency of the incoming modulated receive signal. From this, the bit position of the incoming data can be determined. The value of the incoming data can be determined from whether the VCO output and the demodulator output have consecutive predetermined values.

Abstract: A method is provided for interfacing telecommunication devices. A base unit is connected to a landline for wireless communication. The base unit has a power supply operating at a power supply frequency. A mobile unit is provided for wireless communication with the base unit. The base unit is interfaced to the mobile unit using an interface protocol that has a plurality of frames. Each frame is for transmitting signals from the mobile unit to the base unit and from the base unit to the mobile unit. The frames have a specified frame length. An interference frequency is detected at either the base unit or the mobile unit. The interference frequency is compared with the power supply frequency. The frames are synchronized with the power supply and the specified frame length is adjusted based on the power supply frequency when the interference frequency and the power supply frequency are substantially the same.

Abstract: A method and system are disclosed for avoiding bad frequency subsets in a frequency hopping cordless telephone system. A base station communicates with the handsets using frequencies selected from active frequency subsets. Bad frequency subsets are avoided by monitoring the air interface between the base station and handsets for errors in active frequency subsets. Errors in each active frequency subset are counted during a short-term interval using an associated short-term error counter and during a long-term interval using an associated long-term error counter. After each short-term interval, it is evaluated whether any of the short-term error counters has a value that is greater than a defined threshold. After each long-term interval, it is evaluated whether any of the long-term error counters has a value greater than an error count for a blocked frequency subset.

Abstract: A method and system are provided for synchronizing wireless communication devices. The method and system involve providing a first unit and a second unit for communication over a wireless communication link. Further, an identical identifier is assigned to the first and second units. Also, a data message is constructed having control data. The data message includes a plurality of data bytes and a portion of the control data corresponds to the identifier. The data message is split into a plurality of message portions and the message portions are transmitted from the first unit to the second unit. The message portions are received at the second unit. Control data from the message portions is assembled to form a control message at the second unit. The identifier portion of the control message is compared with the identifier assigned to the second unit. When the identifier portion of the control message matches the identifier assigned to the second unit, the second unit enters an in-synchronization state.

Abstract: According to the invention, a method and an arrangement is provided for digital radio transmission of data between a fixed station (1) and at least one mobile station (2, 3) at one of a plurality of carrier frequencies (f1, f2, etc.) the data being transmitted in time slots (Z1, Z2 etc.) using time-division multiplex method (TDMA) and, in particular if so-called slow hopping RF modules are used, the change from one carrier frequency to another carrier frequency requiring at least a time period corresponding to one time slot. According to the invention, the data are transmitted in two successive active time slots (Z1, Z2) which are followed by an inactive time slot, in which no data are transmitted. The transmission in two successive time slots (Z1, Z2) takes place at the same carrier frequency.

Abstract: A cordless digital telephone system which allows audio broadcasts is provided. Time division multiple access (TDMA) cordless phone systems provide a base unit which is able to provide connections for a plurality of mobile units, such as handsets. With time division, the mobile units are synchronized to different time slots. A broadcast mode is provided that causes the mobile units to be placed in a receive only mode and to synchronize to the same time slot where a broadcast message is sent.

Abstract: A cordless communication system employing an air interface capable of providing both isochronous (e.g., voice) and asynchronous (e.g., data) communication is described. The air interface combines advantages of the HomeRF SWAP and WDCT protocols to provide high quality voice and data service without unnecessarily increasing the complexity of the cordless communication system.