Abstract: A wireless multi-hope network of nodes including data nodes and at least one sink node. The data nodes include battery-powered nodes (BPNs) having active and sleep periods and mains-powered nodes (MPNs) having only active periods, wherein each data node transmits the packets only within corresponding active periods. A BPN includes a transceiver for transmitting and receiving data packets and a processor for determining a schedule of active and sleep periods of the BPN independently from the active and sleep periods of other data nodes in the network and independently from commands transmitted by the sink node, and a battery for providing energy to the transceiver and the processor. The processor switches the transceiver ON and OFF according to the schedule.

Abstract: A method assigns backhaul links in a cooperative wireless network including a control unit (CU) connected to a set of access points (APs) by a set of backhaul links, and wherein the APs are connected to an end user by wireless channels. A reliability of each backhaul link is determined to produce a set of reliabilities. A distance between each AP and the end user is determined to produce a set of distances. Using the set of reliabilities and the set of distances, probabilities of successful reception of a message transmitted from the CU to the end user via the backhaul links and the wireless channels are determined. Then, the backhaul links are assigned according to the probabilities of successful reception of the message by the end user.

Abstract: A method and system determines a location of a device by first measuring, in a receiver of the device, received signal strength (RSS) levels of reference signals transmitted by a set of access points (APs) arranged in an enclosed environment. An expectation maximization procedure is initialized with a uniform distribution of path loss coefficients of the set of APs. An expectation of a joint log-likelihood of the RSS levels is evaluated with respect to the uniform probability distribution of the path loss coefficients, and then updated iteratively until a termination condition is satisfied to produce final path loss coefficients. The location of the device is then based on the RSS levels and the final path loss coefficients.

Abstract: A method for decoding data symbols modulated with a corresponding codeword from a constellation set of codewords expands the constellation set of codewords with a set of basis functions to produce a basis-expanded constellation set and projects projecting a received modulated data symbol onto orthogonal complements of the basis expanded constellation set to obtain a set of distance metric of a generalized likelihood ratio test (GLRT) for each codeword of the constellation set. The set of basis functions includes a Fourier exponential basis function in a frequency domain, a Legendre polynomial basis function in a time domain, and a Fourier-Legendre product basis function in the frequency domain. The method selects a codeword corresponding to a minimal distance metric or a maximal correlation metric and decodes the data symbol from the received modulated data symbol using the codeword.

Abstract: Nodes in a network are clustered by first determining, in each node, a cluster head capability (CHC). The CHC is broadcasting, directly or indirectly, until all nodes have received the CHCs. Each node nominates, one or more candidate cluster heads based on the CHCs, and then, in each node, at least one cluster head is selected from the candidate cluster head nodes based on maximal CHCs.

Abstract: A method for synchronizing a node to a data sink determines a first time of receiving by the node a packet transmitted by a neighboring node and a second time of receiving by the data sink or a synchronized neighboring node the packet transmitted by the neighboring node. The node is synchronized to the data sink based on the difference between the first time and the second time.

Abstract: A method and system use capacity-approaching rateless code to communicate multimedia data even with very short codewords, such as 64 bits or less, via erasure and noise channels. The method provides a way to design the edge degree distribution of rateless codes for any arbitrary channel. Based on an equivalent metric of decoding behavior in any channels, the degree distribution of a rateless code such as Luby-transform codes and raptor codes is optimized based on in-process status of decoding. A regularized least-squares optimization is used to avoid erroneous decoding. Multiple feedbacks can further improve the performance.

Abstract: A method separates a multi-component signal by first estimating parameters of the signal. Then, using periodicity-based algebraic separation and energy-based demodulation, the signal is separated into components according to the parameters and constraints. Last, a Teager-Kaiser energy detector is applied to each component to provide a direct current signal for each component, and the constraint for each component used by the separating.

Abstract: A method detects narrow band interference in wireless networks by first thresholding each block of samples to produce thresholded samples. The samples are normalized frequency magnitudes obtained from a spectrum of a wireless signal in a channel. Each block of the thresholded samples is summed to produce a thresholded value for each block. Then, thresholded values are autocorrelated to determine whether a bandwidth of the wireless signal is consistent with narrow band interference.

Abstract: A method detects symbols in a signal received via a wireless channel by generating a statistical model for each symbol, and determining contribution from all other symbols in the signal as an expected interference. The expected interference is subtracted from the signal to obtain an interference-free signal. Then, the symbol is inferred based on the statistical model and the interference-free signal.

Abstract: A method discovers neighboring nodes in a wireless network of nodes. The nodes include a set of concentrators acting as IPv6 routers and a set of sensor nodes acting as IPv6 hosts. The sensor nodes can also act as relay nodes. In each node, a 64-bit interface ID is configured using a 48-bit MAC address. In each node, a unique IPv6 link-local address is configured using the 64-bit interface ID. In each node, the neighboring nodes are discovered by transmitting unsolicited Neighbor Advertisement (NA) messages. A Router Advertisement (RA) messages is distributed from the concentrators to the sensor nodes meters by using the relay nodes. In each node, a unique IPv6 address is configured and registered at the concentrators by using the relay nodes.

Abstract: Packets are transmitted by a server to mobile nodes in a coverage area of a wireless network using a coverage and reliability map, which indicates qualities and reliabilities of links between the server and the nodes. When a new packet is received in the server, the server transmits the packet if a current load of the packets including the new packet is less than a peak load constraint. Otherwise, the new packet is delayed for one time slot. Packets are transmitted according to associated priorities.

Abstract: A method detects symbols in a signal received via a wireless channel by generating a statistical model for each symbol, and determining contribution from all other symbols in the signal as an expected interference. The expected interference is subtracted from the signal to obtain an interference-free signal. Then, the symbol is inferred based on the statistical model and the interference-free signal.

Abstract: A method and system realize reliable wireless communications in non-coherent multiple-input multiple-output (MIMO) doubly-selective channels. The method uses Grassmannian space-time-frequency block codes and an iterative generalized likelihood ratio test (GLRT) with a multi-dimensional basis expansion model (BEM), decision reordering, and a fixed number of surviving candidates. The computational complexity of a non-coherent MIMO equalizer becomes linear as a function of a code length and a size of a modulation alphabet. The codebook, the alphabet size, the bit labeling, and the block power are optimized using worst-case channel statistics or instantaneous channel states. The method can use soft-information feedback from error correction codes, such as low-density-parity-check codes to improve performance.

Abstract: A method detects narrow band interference in wireless networks by first thresholding each block of samples to produce thresholded samples. The samples are normalized frequency magnitudes obtained from a spectrum of a wireless signal in a channel. Each block of the thresholded samples is summed to produce a thresholded value for each block. Then, thresholded values are autocorrelated to determine whether a bandwidth of the wireless signal is consistent with narrow band interference.

Abstract: A method transmitting packets in a wireless network including a node, a first data sink and a second data sink is disclosed. The method performs a synchronization of the node with the first data sink and the second data sink and transmits first data packets from the node to the first data sink at a first allocated time synchronized with the first data sink. Next, the method transmits second data packets from the node to the second data sink at a second allocated time synchronized with the second data sink. The first and the second data packets are transmitted without updating the synchronization.

Abstract: A method for synchronizing a node to a data sink determines a first time of receiving by the node a packet transmitted by a neighboring node and a second time of receiving by the data sink or a synchronized neighboring node the packet transmitted by the neighboring node. The node is synchronized to the data sink based on the difference between the first time and the second time.

Abstract: A method separates a multi-component signal by first estimating parameters of the signal. Then, using periodicity-based algebraic separation and energy-based demodulation, the signal is separated into components according to the parameters and constraints. Last, a Teager-Kaiser energy detector is applied to each component to provide a direct current signal for each component, and the constraint for each component used by the separating.

Abstract: A method discovers neighboring nodes in a wireless network of nodes. The nodes include a set of concentrators acting as IPv6 routers and a set of sensor nodes acting as IPv6 hosts. The sensor nodes can also act as relay nodes. In each node, a 64-bit interface ID is configured using a 48-bit MAC address. In each node, a unique IPv6 link-local address is configured using the 64-bit interface ID. In each node, the neighboring nodes are discovered by transmitting unsolicited Neighbor Advertisement (NA) messages. A Router Advertisement (RA) messages is distributed from the concentrators to the sensor nodes meters by using the relay nodes. In each node, a unique IPv6 address is configured and registered at the concentrators by using the relay nodes.

Abstract: A method discovers routes for forwarding packets from source nodes (sources) to sink nodes (sinks) in a wireless network, wherein some neighboring sources act as relay nodes. Each source measures a rate of receiving control messages from each neighboring node. Then, the data packets are forwarded from a particular source to the sink via the neighboring nodes having a lowest rate.