Siemens Information & Communication Mobile, LLC

Siemens Communications, Inc.

Siemens Aktiengesellschaft

Siemens Information & Communication Networks, Inc.

Juergen Kockmann

Uwe Sydon

Olaf Dicker

Paulus Sastrodjojo

Sheng Guan

Gerhard Siemens

Holger Steinbach

Hermann-Josef Terglane

Peter Schliwa

Elie Antoun Jreij

Anton Kruk

James S Umstetter

Andreas Mueller

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 (), rather than the number of frames (). Thus, non-interfered with carriers can be used more often than interfered with carriers, thereby improving voice quality.

System and method for adaptive carrier occupancy in a frequency hopping spread spectrum system

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.

Method and system for power-conserving interference avoidance in communication between a mobile unit and a base unit in a wireless telecommunication system

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.

Audio broadcast in cordless digital system

The invention relates to a method and a device for digital data radiotransmission between a fixed station () and at least one mobile station () at one or several carrier frequencies (F, F. . . ), wherein the data is transmitted in several time slots (Z, Z. . . ) 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.

Method and device for effective data radio transmission

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.

Programmable radio receiver bandpass filter for cordless/wireless systems

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 (Z ) in which data are transmitted, and inactive time slots (Z ) 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 ( ) has a burst mode controller ( ) which provides the time-division multiplex frame structure for transmission, and a clock preset device ( ), which presets the clock rate for the burst mode controller ( ). The clock rate which the clock device ( ) presets for the burst mode controller ( ) is twice as high during the inactive time slots (Z ) as during the active time slots (Z ).

Method, mobile station and base station for transmitting signals

A system and method for call screening in a wireless telephone system. When a call is received on an answering machine ( ) associated with a base part ( ), the user at a portable part ( ) may select a call screen button ( ). The resulting signal is received at the base part ( ), which then enters a broadcast mode. The incoming answering machine message is broadcast to all handsets ( ). In a TDMA system, an audio message is broadcast from a base part ( ) 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.

System and method for answering machine call screening in a cordless digital system

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.

Method and system for improving voice quality in cordless communications

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.

Method and system for avoiding periodic bursts of interference in wireless communication between a mobile unit and a base unit

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. A blocked frequency subset is then substituted for an active frequency subset if an associated short-term error counter is greater than the defined threshold or if a long-term error counter is greater than the error count for a blocked frequency subset.

Method and system for avoiding bad frequency subsets in a frequency hopping cordless telephone system

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. When the identifier portion of the control message is different from the identifier assigned to the second unit, the second unit enters an out-synchronization state. At least one prior control message is searched for the identifier assigned to the second unit when the second unit is in the out-synchronization state. A matching identifier is synchronized with when the matching identifier is found in the prior control messages. When the prior control messages are free of the identifier, the second unit resynchronizes with the first unit.

Method and system for wireless communication incorporating distinct system identifier bytes to preserve multi-frame synchronizaton for systems with limited control channel bandwidth

According to the invention, a method and an arrangement is provided for digital radio transmission of data between a fixed station ( ) and at least one mobile station ( ) at one of a plurality of carrier frequencies (f , f , etc.) the data being transmitted in time slots (Z , Z 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 (Z , Z ) which are followed by an inactive time slot, in which no data are transmitted. The transmission in two successive time slots (Z , Z ) takes place at the same carrier frequency. If the method or the arrangement according to the invention are used for the purpose of matching the DECT standard to the US-American ISM band, six time slots for transmitting from the fixed station to at least one mobile station can be followed by six time slots for transmitting from the at least one mobile station ( ) to the fixed station ( ).

Method and device for radio transmission of data by means of frequency hops

A method and system are provided for wireless communication. A base unit and a mobile unit are provided which are operable to communicate over an air interface having a plurality of channels. The method and system further include transmitting from the mobile unit a message on a selected channel for a first predetermined time. The channels are scanned at the base unit. Also, the message is detected at the base unit on the selected channel and the selected channel is used as an initial channel for a wireless communication link between the mobile unit and the base unit.

System and method for synchronization concept for 2.4 GHz direct sequence spread spectrum cordless telephone system

The present invention comprises a system for mobile communications. The system comprises a base station (,) having logic for evaluating parameters relating to the quality of individual communication links (,) between the base station (,) and each of a plurality of mobile units and selecting those parameters that optimize the quality of the communication link (,) for each individual mobile unit. The system also comprises circuitry residing in each mobile unit for establishing an optimized communication link (,) with the base station (,). In accordance with another aspect of the present invention, a method is disclosed for mobile communications comprising three steps. In step one, parameters representative of transmission quality for individual communication links (,) between a base station (,) and each of the plurality of mobile units are monitored. In steps two, the parameters for each of the individual communication links (,) are evaluated to determine the optimum quality for each link. In step three, transmission attributes are selected in response to the evaluated parameters to optimize the transmission quality of each link.

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Duesseldorf, Germany

Juergen Kockmann