Abstract: A method determines a position of a target object. A window function is applied repeatedly to a first signal and a second signal of a pair of radio signals received at a pair of passive sensors from a target object while time shifting the window function during a correlation interval to produce a first windowed signal and a second windowed signal for each application. The first windowed signals are cross-correlating with the second windowed signals to determine a peak for each cross-correlation. The peaks are compared sequentially in time with a predetermined threshold to detect a first pulse in the first signal and a first pulse in the second signal. A delay between the first pulses indicative of a position of the target object.

Abstract: A method and system detects a target in a cooperative passive radar system. In each of multiple passive sensors, signals are detected that emanate from a target. Information is extracted from the signals and broadcast to other passive sensors. The sensors update parameters according to the information to improve a likelihood of receiving the signals and to increase a probability of detecting the target. The information is also transmitted to a central processor. The central processor determines a position of the target.

Abstract: A method estimates a distance between transceivers in a wireless communications network. A first time interval T is set in a transmitter and a receiver. A signal is transmitted from the transmitter to the receiver at a time t2 according to a first clock of the transmitter. The signal is received in the receiver at a time t3. Processing delays of the receivers are determined. A reply to the signal is sent from the receiver to the transmitter at a time t6 such that |t3?t6|=T. The reply is received in the transmitter at a time t7 of the first clock and a distance d between the transmitter and the receiver is determined according to d=c(|t2?t7|?T)/2, where c is the speed of light.

Abstract: According to the invention, IEEE 802.15.4a packets are used for communications, ranging and passive radar (detecting changes/motions, tracking objects in the environment) functionality. Changes and motions in the environment are detected by exploiting the specific preamble structure of the IEEE 802.15.4a packets. A sequence of packets transmitted through an environment is received. Each packet includes a preamble. The preamble in each packet is despread to update a reference multipath profile and to obtain a current multipath profile for a currently received packet. The reference multipath profile is compared with the current multipath profile to detect an object in the environment.

Abstract: A method and apparatus for transmitting a packet in a wireless communications network is presented. A packet is constructed to include synchronization header, a physical layer header, and a payload. A preamble and a start of frame delimiter is inserted in the synchronization header. Multiple pairs of cores and of suffixes are inserted in the start of frame delimiter, and then the packet is transmitted.

Abstract: A method and apparatus for transmitting a packet in a wireless communications network is presented. A packet is constructed to include synchronization header, a physical layer header, and a payload. A preamble and a start of frame delimiter are inserted in the synchronization header. Multiple fixed length ternary sequences are inserted in the start of frame delimiter in an arbitrary order, and then the packet is transmitted.

Abstract: With multiple predictors, a method dynamically allocates bandwidth to traffic having a variable data rate in a network. A first amount P-I of bandwidth is allocated in a first state of a state machine. A second amount P-II of bandwidth is allocated in a second state of the state machine, and a third amount of bandwidth P-III is allocated in a a third state of the state machine such that P-II>P-I>P-III. Cost functions are periodically evaluated to transition between the first, second, and third states of the state machine.

Abstract: A system and method selects a circuit to service an application request to transmit data over a network. The network includes one or more low and high bandwidth circuits. An average utilization is measured for each circuit in a circuit analyzer should the application request be assigned to the circuit. Then, application request is assigned to the high bandwidth circuit if the average utilization is less than a predetermined threshold, assigning to the low bandwidth circuit if the average utilization is less than one, where one is a full utilization, and declined otherwise. The threshold is one minus a guard bandwidth of the high bandwidth channel.

Abstract: A method for estimation a time-of-arrival of a radio signal is provided. The signal is an ultra-wideband (UWB) signal. The method uses kurtosis of the received signal to estimate an energy threshold of the signal. The energy threshold can be used to determine a time-of-arrival of the signal.

Abstract: A transmitted reference ultra-wide band communication signal embodied in an electromagnetic wave and configured to communicate a data value includes a first frame having a first reference pulse and a first data pulse. The first reference pulse has a reference polarity and the first data pulse has a data polarity. The first reference pulse is separated from the first reference pulse by a delay time. The reference polarity is set based on a predetermined reference value and a first pseudo-random polarity code sequence, and the data polarity is set based on the data value and a second pseudo-random polarity code sequence. A receiver configured to receive the signal, a transmitter configured to transmit the signal, and a system of transmitters and receivers are also provided.

Abstract: A method and system connects a first terminal via multiple networks to a second terminal. An environment description is acquired and parsed by a description parser into cost parameters using a set of rules. An objective function evaluates the cost parameters to determine an optimal path to connect the first terminal to the second terminal through the multiple networks using a switch. The selection of the optimal path can be done periodically during a particular application session.

Abstract: A method traces a route in a wireless network including nodes. A trace packet is generated in a tracer node. The trace packet includes addresses of a source node and a destination node in a route. The trace packet is sent from the tracer node to the source node, and then along the route to the destination node. In response to receiving the trace packet in each node along the route, a report packet is sent to the tracer node.

Abstract: A method estimates a time of arrival of a signal received in a wireless communication system. An energy in a frame of a received signal is measured to determine a block in the frame, the block representing a coarse time of arrival of the received signal. Multiple time-delayed versions of a template signal are combined with the block of the received signal to select a particular template signal. The particular template signal identifies a particular chip representing a fine time of arrival of the received signal.

Abstract: A system and method reduce power consumption in a multi-hop wireless communications network. A signal is received from a source node in an intermediate node. The signal includes a request to relay a message to a destination node. The request includes information on power requirements to relay the message either in a relay mode or a regeneration mode. If the available power at the intermediate node exceeds the power requirements, then the request is accepted. Either the relay mode or the regeneration mode is selected, based on criteria for retransmitting the message, and the message is then relayed to the destination node using the selected mode.

Abstract: A method estimates a distance between transceivers in a wireless communications network. A first time interval T is set in a transmitter and a receiver. A signal is transmitted from the transmitter to the receiver at a time t2 according to a first clock of the transmitter. The signal is received in the receiver at a time t3. Processing delays of the receivers are determined. A reply to the signal is sent from the receiver to the transmitter at a time t6 such that |t3?t6|=T. The reply is received in the transmitter at a time t7 of the first clock and a distance d between the transmitter and the receiver is determined according to d=c(|t2?t7|?T)/2, where c is the speed of light.

Abstract: A method dynamically allocates bandwidth for traffic having a variable data rate in a network. A data rate of the traffic received from the network is measured during fixed length time intervals. A predetermine number of consecutive data rates are grouped into overlapping vectors. A discrete wavelet transform is applied to each overlapping vector to determine frequency bands for each vector, and the frequency bands of each vector are analyzed to determine an associated energy of the data rate. Then, the bandwidth is allocated to the traffic according to the associated energy when the traffic is transmitted.

Abstract: A system delivers multimedia services to mobile devices via a network by first registering a mobile device with a service manager connected to the mobile device via the network. Application service providers are connected to the service manager via the network. Each application service provider is associated with particular multimedia services. An environment description to be associated with the mobile device is acquired, and a particular application service provider is identified according to the environment description, and then selected services provided by the particular application service provider are delivered to the mobile device according to the environment description via the network.

Abstract: A method signals in an ultra-wide bandwidth network. A data symbol is generated. A set of reference pulses is transmitted for the data symbol. Each reference pulse is of a different type. One data pulse is also transmitted for each reference pulse. A type of each data pulse is identical to the type of the corresponding reference pulse.

Abstract: A method of communicating information in a communication network with a plurality of hierarchically addressed nodes includes receiving communication packets identifying 1-hop neighbor node addresses, a number of on-tree neighbors of neighbor nodes transmitting the received packets, and forwarding node addresses of forwarding nodes from which information in the received packets are to be rebroadcast. Further, the method includes identifying each 1-hop neighbor node which should be a forwarding node based on stored addresses and numbers of on-tree neighbors, and producing and transmitting a rebroadcast packet including addresses of forwarding nodes. A communication network system, a communication node in a communication network, and a computer program product include similar features. Communication packets embodied in an electromagnetic wave includes an address, a number of on-tree neighbors of neighbor nodes, and forwarding nodes from which the packets are to be rebroadcast.

Abstract: A method determines a delay for rebroadcasting a packet received in a node via a channel of a wireless network. After the packet is received, the node measures a quality of the channel of the network. A broadcast degree of the receiving node is determined, and a delay for rebroadcasting the packet is set as a function of the quality and the broadcast degree.