Abstract: A location of a mobile device within a network is determined. The network includes a plurality of fixed nodes. A method includes receiving, at the plurality of fixed nodes, receive messages transmitted from the mobile communication device. Each of the plurality of fixed nodes generates a receive count stamp for each receive message corresponding to a local counter value at the receipt of the receive message. At each of the plurality of fixed nodes, the method includes processing the receive count stamps to calculate a set of pseudo-ranges between the respective fixed node and the mobile device, and measuring multipath delay included within the set of pseudo-ranges. Based on the measurement, the multipath delay is removed from the set of pseudo-ranges to determine a range estimate between the mobile device and each of the fixed nodes. Based on the range estimates, a location of the mobile device is calculated.

Abstract: A location aware intelligent transportation system determines ranges between a plurality of communication devices, including at least one mobile communication device. A method includes receiving receive messages transmitted from a plurality of other communication devices. Each receive message includes a transmit count stamp corresponding to a remote counter value. The mobile communication device generates a receive count stamp for each receive message. The method includes dynamically associating and disassociating the mobile communication device with a plurality of sub-groups of the plurality of other communication devices. The associating and disassociating are based at least in part on receiving receive messages from a predetermined number of other communication devices for each sub-group.

Abstract: Space-time solutions are determined by exchanging pings among nodes in a network. Each ping includes a current space-time state of the transmitting node, which includes the transmitting node's currently estimated location and corrected time (as a count stamp). A particular node in the network receives pings from the other nodes in the network and uses the data in the received pings to estimate its own current position and to correct its own free-running clock relative to a common system time. As a service to the network, the particular node then transmits its corrected time (as a count stamp) and estimated position to the other nodes. In some embodiments, the space-time solutions discussed herein are used as backup to other navigation systems, such as the Automatic Dependent Surveillance—Broadcast (ADS-B) system.

Abstract: Space-time solutions are determined by exchanging pings among nodes in a network. Each ping includes a current space-time state of the transmitting node, which includes the transmitting node's currently estimated location and corrected time (as a count stamp). A particular node in the network receives pings from the other nodes in the network and uses the data in the received pings to estimate its own current position and to correct its own free-running clock relative to a common system time. As a service to the network, the particular node then transmits its corrected time (as a count stamp) and estimated position to the other nodes. In some embodiments, the space-time solutions discussed herein are used as backup to other navigation systems, such as the Automatic Dependent Surveillance-Broadcast (ADS-B) system.

Abstract: A method solving for unknown location values and clock rate values of one or more nodes of a network of nodes communicating with one another entails associating multiple transmitting nodes and receiving nodes that produce, respectively, ping transmit events and ping receive events by receiving and associating receive count stamps to the ping transmit events. Ping event values corresponding to ping events relating to associated ones of the ping transmit events and the ping receive events are generated and accumulated. Solutions for transmit and receive node clock rate values and node location values relating to the transmit and receive ping events at arbitrary times within a harmonic block time interval are generated from the grouped, accumulated ping event values. The generated solutions for one of the associated multiple nodes are a function of the ping transmit events and ping receive events produced by the others of the associated multiple nodes.

Abstract: Space-time solutions are determined by exchanging pings among nodes in a network. Each ping includes a current space-time state of the transmitting node, which includes the transmitting node's currently estimated location and corrected time (as a count stamp). A particular node in the network receives pings from the other nodes in the network and uses the data in the received pings to estimate its own current position and to correct its own free-running clock relative to a common system time. As a service to the network, the particular node then transmits its corrected time (as a count stamp) and estimated position to the other nodes. In some embodiments, the space-time solutions discussed herein are used as backup to other navigation systems, such as the Automatic Dependent Surveillance-Broadcast (ADS-B) system.

Abstract: A space-time calibration system and method implement space-time solutions, in which, in one preferred embodiment, a single node determines its own space-time solutions based on other network nodes with which the single node communicates. In other preferred embodiments, space-time solutions for the node can be generated using other resources in the network. The disclosed system and method enable reliable, precise object positioning particularly for environments where the Global Positioning System (GPS) is blocked or subject to interference such as within the urban core.

Abstract: A system for determining location and timing information in a cellular network includes a space-time calibration unit (SCU) and a plurality of nodes in communication with the SCU. Each node includes a node ping driver that receives frame synchronization information from a respective subset of cell sites, and associates the frame synchronization information with respective receive count stamps generated using a local node clock. The system also includes a user handset that includes a handset ping driver that receives the frame synchronization information from a serving cell site and one or more neighbor cell sites, and associates the frame synchronization information with respective receive count stamps generated using a local handset clock. The SCU uses the information from the node and handset ping drivers to determine a handset location.

Abstract: The location of one or more mobile nodes in a wireless local area network (WLAN) is determined. Nodes in the WLAN include respective ping drivers to generate ping event values related to transmit count stamps and receive count stamps for wireless messages exchanged between the nodes. Each wireless message is associated with a transmit offset corresponding to an expected transmit time. A sorting module groups the ping event values and produces a difference between the respective receive count stamps and the transmit count stamps for each wireless message. Based on the sorted ping event values, the sorting module generates transmit offset values relating to the transmit offsets. A space-time calibration unit generates, from the sorted differences and the transmit offset values, a clock rate solution and a location solution for at least one of the nodes in the WLAN.