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.

Abstract: Methods and apparatus for combined wireless telephony and data communication of the present invention include providing a Home RF transceiver and a WDCT transceiver in a common enclosure and synchronizing the operation of the Home RF transceiver to specific time slots in the WDCT TDM frame. More particularly, the Home RF transceiver is prevented from transmitting whenever the WDCT transceiver is receiving and is prevented from receiving whenever the WDCT transceiver is transmitting. This effectively prevents the Home RF transceiver from interfering with the WDCT transceiver and vice versa. According to a presently preferred embodiment, synchronization is keyed to the repeating WDCT TDM frame but is dynamically adjustable based on the actual use of bandwidth by the WDCT devices. Thus, when there is no telephony traffic, the Home RF transceiver has full bandwidth. For each WDCT telephone call in progress, no more than {fraction (1/12)} of the Home RF transceiver bandwidth is sacrificed.

Abstract: A cordless digital telephone system which allows call screening 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. In this way, an incoming call can be recorded substantially simultaneously with being broadcast to any number of mobile units, any of which can elect to pick up the incoming call. Once so elected, the base station is reset to a standard mode thereby permitting an uninterrupted conversation between a caller and a user of the mobile unit as a callee.

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 cordless communication system for use in a wireless network that is capable of providing efficient use of available frequency spectrum within a given physical space is disclosed. The cordless communication system is comprised of a central unit and at least two remote units that are capable of direct communication with each other via wireless connections assigned and coordinated by the central unit.

Abstract: A frequency hopping cordless telephone system is provided, including a base station and one or more mobile units. The base station and mobile units are adapted to determine if a carrier frequency has been interfered with. If so, and if a next frame has slots available, the lost slot(s) are resent, along with those next in queue. A ring buffer memory is provided to receive both the resent slot(s) and the current one. The slots are read into the memory at a first rate and read out at a higher rate.

Abstract: 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.

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: 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 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: The present invention comprises a system for mobile communications. The system comprises a base station (12) having logic for evaluating parameters relating to the quality of individual communication links (14a-17a) between the base station (12) and each of a plurality of mobile units and selecting those parameters that optimize the quality of the communication link (14-17) for each individual mobile unit. The system also comprises circuitry residing in each mobile unit for establishing an optimized communication link (14-17) with the base station (12). 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 (14a-17a) between a base station (12) and each of the plurality of mobile units are monitored.

Abstract: A method and system for table implemented frequency selection in a frequency hopping cordless telephone system is provided. A first table comprising an array of sequence numbers is maintained. A second table comprising an array of channel numbers is also maintained. A sequence number is selected from the first table by using a table arrangement number and a subset counter. A channel number is selected from the second table using the sequence number and an index counter. A selected frequency is derived from the channel number and the subset counter.

Abstract: A method and system are disclosed for shifting frequency subsets to avoid base station interference in a frequency hopping cordless telephone system. A base station communicates with the handsets using frequencies selected from active frequency subsets. Frequency subsets are shifted to avoid interference by selecting frequencies initially from a defined number of active frequency subsets where each of the active frequency subsets is used before repeating an active frequency subset. The number of active frequency subsets is then changed for a defined period of time to change the period with which the active frequency subsets are used. After the defined period of time, the number of active frequency subsets is returned to the defined number of active frequency subsets.

Abstract: Carrier signals received by a receiver architecture for an amplitude spectrum of the carrier signal prescribed by the employment of the receiver architecture even given small modulation indices, a low-noise amplifier (VS) preceding a synthesizer (SYN) of the receiver is either turned off dependent on the field strength received with the carrier signal or is fashioned such that the maximum output power of the amplifier (VS) at the possible amplitude spectrum of the carrier signal never lies above the compression point of the mixer/mixers in the synthesizer (SYN).