Vtech Telecommunications Limited

Vtech Communications Limited

Milosh Koprivica

Sukhdeep Singh Hundal

Ralph Tischler

Sarkis Teghararian

Dion Michael Horvat

A technique for time domain avoidance of communications link interference sources characterized by intermittent, periodic short bursts of energy. A transmitting source can be assigned two time slots within a time domain multiple access data frame over which each data packet can be transmitted. The time slots are separated by a duration greater than that of an interference burst, such that an interference burst does not affect both time slots in any given frame. Therefore, the data packet can be received on at least one of the two assigned time slots. Transmitter power consumption can be reduced by calculating the timing of the periodic interference bursts, and only transmitting a data packet on one of the two assigned time slots that will not coincide with an interference burst in each frame. Communications link capacity can be improved during the presence of interference by synchronizing the data frame to the timing of the interference bursts. The bursts then occupy fixed time slots in each data frame, enabling standard single time slot transmissions for the remaining communications channels in the data frame.

Communications apparatus and method to avoid interference

Method for avoiding interference in a digital communication system

A system and method for avoiding mutual interference between two communications system is disclosed. One embodiment of the invention provides a system that includes a fixed unit and a portable unit. The fixed unit has a fixed transceiver. The portable unit has a portable transceiver. The fixed transceiver and the portable transceiver are members of a first RF system of the first RF system. The portable transceiver is configured to communicate with the fixed transceiver via a first RF link of the first RF system. The system further includes an additional transceiver. The additional transceiver is configured to communicate with a headset via a second RF link of a second RF system. The system further includes a processor that is coupled to one of the fixed transceiver, the portable transceiver, and the additional transceiver. The processor is configured to avoid interference between the first RF link and the second RF link. The interference can be avoided by coordination between the first RF system and the second RF system. Alternatively, the interference can be avoided using signal or timing information from the second RF system. For example, RSSI obtained by the first RF system can be used to estimate or derive timing information of the second RF system, which can then be used by the first RF system to avoid interference with the second RF system.

System and method for avoiding interference between two communications systems

A method for reducing interference from a wireless communications system. The interference threshold is set based on a quality criterion that can be measured during operation of the system. The quality criterion is measured during system operation. Preferably, a separate quality criterion measurement is performed for each of an uplink and a downlink of the wireless communications system. The quality criterion is compared to the information containing the set interference threshold. A breach of the interference threshold for the uplink or the downlink is determined when the measurement indicates that the measured quality criterion is sufficiently poor that operation of the system should be modified. Upon determination of an interference breach in either the uplink or downlink, the system initiates an asymmetric enhanced mode operation in which redundant data transmission is established over the link exhibiting the interference breach, while standard, non-redundant transmission continues on the other link.

System and method for asymmetric enhanced mode operation in a digital communication system

A system and method for avoiding interference between two communications system is disclosed. A preferred embodiment of the invention provides a method that obtains frequency information associated with a first RF link between a handset of a cordless telephone and a headset. Using the frequency information, the method then generates an RF channel for a second RF link between the handset and a base unit of the cordless telephone. The RF channel is different from one or more RF channels associated with the first RF link. Preferably, the headset is a Bluetooth headset. Preferably, the first RF link is a Bluetooth RF link. Preferably, the second RF link is a WDCT RF link.

System and method for avoiding interference among multiple wireless systems

A reliable data communications protocol for the broadcast of long messages over a noisy medium, such as a frequency hopping communications link with multiple interferors. Long length messages are divided into a plurality of subpackets, each of which incorporates an error detection mechanism. A message integrity field is calculated based upon the contents of the subpackets, and is stored within one of the plurality of subpackets. The subpackets are transmitted two or more times. Each subpacket is stored by a recipient if received without error, and the recipient calculates a message integrity field based upon the stored subpackets. When the calculated message integrity field corresponds to the message integrity field received within the subpackets, the long message is deemed properly transmitted, reassembled from the plurality of subpackets, and processed appropriately.

Broadcast in a wireless communications system

A method for identifying interferers in a radio communication band, such as the 2.4 GHz ISM band, uses a priori information of the interferers such as channel structure, channel frequency and channel bandwidth. Measured RSSI can be used to detect and identify interferers. RSSI measurements can be made at multiple frequencies within a channel of the interferer. Randomization of RSSI measurements improves the likelihood of interferer detection and identification if such interferer is present. Metrics other than RSSI can be used.

System and method for identifying interferes in a communication spectrum

A method of dynamic channel allocation in a frequency hopping communications system is disclosed providing improved efficiency and reliability. During the course of communications between a plurality of transceivers over a frequency hopping wireless communications link, a transceiver begins evaluating the performance of each channel in the hop sequence, starting at a fixed point in the sequence. The transceiver proceeds sequentially through the hop sequence, until a channel fails to satisfy a predetermined quality criterion. A channel which fails to satisfy the quality criterion is considered bad, and substituted with a replacement channel from a set of available channels via an unacknowledged channel replacement command. The channel evaluation process is subsequently reinitiated beginning anew at the fixed point in the hop sequence, thus operating to maintain a set of consecutive good channels.

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Richmond, CA, United States of America

Milosh Koprivica