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Abstract

A method for maximizing the data throughput over a multi-code DS-CDMA network by controlling the number of codes assigned to each user while controlling the power budget of each user so that each users bit energy to noise ratio is met along with the quality of service and frame error rate requirements. A method is also provided for maximizing the throughput over a variable gain DS-CDMA network in which each user uses only one code and changes the data rate and power to meet quality of service requirements.


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Abstract

In a free space communication network in which different communication nodes are linked together by directed beams, a method for dynamically configuring the topology of the network allows the transmission directions of the communication nodes to be autonomously changed to communicate with a new node as dictated by the needs of the network. Moreover, the nodes can be switched from directional to broadcast and back again on an as-needed basis.


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A video encoding/decoding system based on 3D wavelet decomposition and the human perceptual model is implemented. JND is applied in quantizer design to improve the subjective quality of compressed video. The 3D wavelet decomposition helps to remove spatial and temporal redundancy and provides scalability of video quality. In order to conceal the errors that may, occur under bad wireless channel conditions, a slicing method and a joint source channel coding scenario, that combines RCPC with CRC and utilizes the distortion information to allocate convolutional coding rates are proposed.


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Abstract

Location update techniques are described. A dormant mobile node updates its location information by sending a first message over a wireless link to an access node. The access node generates a second update message in response to the first message. The second message includes a mobile node identifier and, in some embodiments is directed to the mobile node. The second message is received by a tracking agent, which updates location information corresponding to the mobile node.


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Abstract

Signal, e.g., message, security techniques are described for wireless systems. A first signal is received by an access node via a wireless link. The signal includes a first authenticator that was generated by the transmitting device, e.g., wireless terminal. The access node determines from an attribute of the signal at least some information known to both the access node and transmitting device but which was not transmitted as part of the message content. The determined information was used by the wireless terminal in generating the first authenticator.


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Abstract

Routing of packets to a mobile node in a packet switching network is controlled.


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Abstract

A system and method for optical wireless communication with fading resistance. A delayed diversity approach reduces fading significantly. Data is sent in a set of light signals (also called diverse light signals) which each have a different polarization and/or a different wavelength. The diverse light signals are also temporally different in that they are transmitted in a delayed fashion with respect to one another. In this way, each light signal is carried over a different, uncorrelated "channel" through the atmosphere.


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