Abstract:
A system and method for using subnet relations to determine paging areas, for performing authentication and association, and to activate access network interfaces in wireless communication devices in a heterogeneous access network. Paging areas are generated using subnet relations by determining mobility agent servers within a predetermined number of subnet relations from a last active mobility agent server. Authentication and association are also accomplished using subnet relations. Access network interfaces can also be turned on and off based on subnet relations thereby conserving battery power.
Abstract:
A data transmission system has a base station and at least one mobile station. Data packets are interchanged between the base station and the mobile station using a time slot method. In this case, first measures are used for transmission of a first part of a data packet at a predetermined first symbol rate and at a first transmission frequency, and second measures are used for transmission of a second part of the data packet at a second symbol rate and at a second transmission frequency.
Abstract:
An economical, reliable, robust and easy to use multi-user voice communication system and method suitable for use in rapidly evolving tactical or hazardous situations continuously permits each user to hear every voice communication occurring among the other users, no matter when each user speaks, and no matter how many users try to speak at once. One may characterize this as a wearable party-line radio network, because it works like a wireless party-line telephone service in that all users continuously hear every speaker, even when speaking simultaneously. The system is transportable and operable without requiring any set-up procedure or installation of a central hub or router for controlling a varying number of users when moving. Each user carries a transceiver handset with one transmitter and two or more transceivers tuned to the other transmitters in a group.
Abstract:
The present invention relates to a method of controlling at least one transmission parameter of a connection between a transmitting station (BS) and receiving station (MS0. The method comprises the steps of receiving at the receiving station a transmission signal from the transmitting station, determining from the received transmission signal whether there exists a power up requirement or a power down requirement, and monitoring the distribution of the power up and power down requirements over a period. If a predefined form of the distribution is detected, the quality target of the connection is changed. The present invention relates also to an arrangement and a receiving station for implementing the method.
Abstract:
Techniques for efficient W-CDMA modulation are disclosed. In one aspect, a multiplexing/coding chain for use in modulation such as that defined by the W-CDMA specification is disclosed. In another aspect, transport blocks are processed and concatenated, utilizing memory efficiently. This aspect has the further benefit of preparing transport channels for efficient subsequent processing. It also allows for ease of interface with the transport channel source. In another aspect, the use of repeated channel coding is used in lieu of an interleaver memory to provide channel coding and interleaving. These aspects, collectively, yield the advanced benefits of a system, such as W-CDMA, in a hardware efficient manner. The techniques described herein apply equally to both access points and access terminals. The techniques are not limited to W-CDMA systems; they are quite suitable to other systems requiring the various benefits the invention offers. Various other aspects of the invention are also presented.
Abstract:
A wireless communication system (200, 300, 400, 500) mitigates the effects of excess timing delay caused by varying lengths of communication paths. In one general implementation, a transition communication path (206, 323, 329) is used to transfer a time-advanced version of a timing reference signal so that the cumulative time delay at a transition cell (209, 325, 331) is reduced. In another general implementation, the timing reference signal is time-advanced in all communication paths (403-411), and selected communication paths (403-407) include a time delay means (423-427, 503-507) such that the cumulative time delay at an area (421) near a target coverage area (130) is reduced. By reducing the cumulative time delay at the area (421) near the target coverage area (130), a handoff of a communication of a mobile station (128) into the target coverage area (130) can be performed.
Abstract:
A communications system and network wherein communications links between subscribers are established by retrodirective oscillating loops between each subscriber and a node station. Provision is also made for establishment of links between nodes so that remotely located subscribers can communicate. Information is transmitted between subscribers by using a mixing process in the node whereby information transmitted from one subscriber to the node is transferred at the node to a carrier signal transmitted between the node and another subscriber.
Abstract:
An adaptive transmitter power control for use in satellite communications systems. The power control provides real-time adjustment of satellite transponder power on the basis of received signal quality so as to overcome the effects of rapid onset signal attenuation occurring within the system, such as would be caused by a rainstorm. The communication system includes at least two ground stations communicating with one another via a satellite transponder whose power output is functionally dependent upon received signal strength. The level of transmitter power utilized by the satellite is adjusted by adjusting the power level of the signal transmitted to the satellite by at least one of the ground stations. At least another of the ground stations includes a quality monitor which responds to soft decisions generated by the ground station in demodulating the signal received from the power controlled ground station via the satellite repeater. The quality monitor makes a real-time determination of the quality of the received signal on the basis of the magnitude of these soft decisions. Transmitter power adjustment commands are generated in accordance with this determination. In systems wherein the primary data communicated between the stations is encoded in an error-correcting code, the power adjustment commands are communicated to the power controlled ground station by intentionally inserting errors in the error-correcting coded data.
Abstract:
A space diversity PCM-TDMA telecommunication system using a stationary communication satellite, in which fixed delay circuits are respectively inserted in the sending side and the receiving side of one route at a control equipment, while variable delay circuits are inserted in the sending side and the receiving side of the other route at the control equipment, so that electrical length of one route from the satellite to the control equipment may be the same as that of the other route from the satellite to the control equipment through the route including connection links between the two sites. Diversity switching can be performed with no duplication and lack of signals in accordance with the above construction.
Abstract:
A satellite up link diversity switch system. A beacon or reference signal received from the satellite at two locations separated in an east-west direction. Diversity logic compares the two signals received and switches the output of a UHF transmitter to whichever antenna is receiving the stronger signal at the time.