Abstract: A method of acknowledged communication in a network includes transmitting a message to at least one node of the network, wherein the message is transmitted in each of a plurality of broadcast rounds that overlap one another according to a predetermined broadcast schedule, receiving the message by the at least one node, and transmitting an acknowledgement of the message from the at least one node, wherein the acknowledgement is transmitted in each of a plurality of collection rounds that overlap one another according to a predetermined collection schedule.

Abstract: A system and method for operating a wireless network provides for sending a wakeup tone, periodically waking up from a sleep mode to listen for the wakeup tone, upon receiving the wakeup tone, listening for at least one second tone, the at least one second tone being one of (i) a tone in a frequency different from the wakeup tone and (ii) a pattern of tones including at least one frequency different from the wakeup tone, and upon receiving the at least one second tone, performing an action based on the at least one second tone.

Abstract: A method for providing electronic communications between wireless nodes includes wirelessly transmitting data from a transmitting one of the nodes to a plurality of receiving ones of the nodes. A respective first acknowledgment tone is wirelessly transmitted from each of the receiving nodes to the transmitting node and to each other one of the receiving nodes. Each first acknowledgment tone is transmitted in response to the respective receiving node receiving the transmitted data. Each of the first acknowledgment tones is transmitted in a respective, unique time slot. At least one second acknowledgment tone is wirelessly transmitted from at least one of the nodes to each other one of the nodes. The second acknowledgment tone is transmitted dependent upon whether a group of received first acknowledgment tones matches a group of expected-to-be-received first acknowledgment tones.

Abstract: A method of operating wireless devices includes providing a plurality of sender nodes each having a respective message to wirelessly send to a receiver node. A probability distribution is assigned to a plurality of frequency channels such that a respective probability of selection is assigned to each frequency channel. At least two of the probabilities of selection are unequal. A respective frequency channel is probabilistically selected for each of the sender nodes according to the probability distribution. The messages are wirelessly sent from the sender nodes to the receiver node in the selected frequency channels. The receiver node is used to sample a first one of the frequency channels and a second one of the frequency channels. The second frequency channel has a higher respective probability of selection than the first frequency channel.

Abstract: A method of synchronizing wireless devices includes establishing a recurring sequence of frequency channels at which the wireless devices are to communicate. The frequency channels are divided into a plurality of groups. Synchronization information is transmitted at a respective first frequency channel in each of the groups of frequency channels during a first sampling time period. One of the groups of frequency channels is selected. A wireless device is used to sample each of the frequency channels in the selected group during the first sampling time period. Non-synchronization information is transmitted after the first sampling time period. Synchronization information is transmitted at a next respective frequency channel in each of the groups of frequency channels during a next sampling time period. The next sampling time period occurs after the transmitting of the non-synchronization information.

Abstract: A wireless networking method includes providing a plurality of different sets of wireless links and a plurality of wireless nodes. The nodes are in mutual bidirectional wireless communication via the wireless links. Each of the links enables the communication between a respective pair of the nodes. Information is transmitted to a selected one of the nodes from each of other ones of the nodes via a first of the sets of the wireless links. The step of transmitting information to the selected one of the nodes from each of other ones of the nodes is repeated via each of other ones of the sets of the wireless links, respectively.

Abstract: Embodiments of a link assessment and frequency monitoring system for use in wireless sensor networks are described. In one embodiment, each frequency utilized by links coupling two or more nodes in the network is sampled to determine a noise measure for each frequency. A correlation measure based on the distance between the noise measures for each pair of frequencies is determined. The frequencies are then clustered into a number of groups of frequencies based on the correlation measure between each pair of frequencies, such that the number of groups is less than the total number of frequencies. A representative frequency for each group of frequencies is selected, and a link quality assessment for each pair of nodes in the network is performed for the representative frequency of each group of frequencies.

Abstract: A system and method for operating a wireless network provides for sending a wakeup tone, periodically waking up from a sleep mode to listen for the wakeup tone, upon receiving the wakeup tone, listening for at least one second tone, the at least one second tone being one of (i) a tone in a frequency different from the wakeup tone and (ii) a pattern of tones including at least one frequency different from the wakeup tone, and upon receiving the at least one second tone, performing an action based on the at least one second tone.

Abstract: A method and system for determining a location of at least one stationary node of a wireless network, which includes providing a predetermined path within a geographic space of the wireless network, prior to localization, moving a mobile node along the predetermined path, measuring a network parameter with respect to the mobile node as it moves along the predetermined path, and performing a localization scheme to estimate the location of the at least one stationary node using the measured network parameter.

Abstract: A method of acknowledged communication in a network includes transmitting a message to at least one node of the network, wherein the message is transmitted in each of a plurality of broadcast rounds that overlap one another according to a predetermined broadcast schedule, receiving the message by the at least one node, and transmitting an acknowledgement of the message from the at least one node, wherein the acknowledgement is transmitted in each of a plurality of collection rounds that overlap one another according to a predetermined collection schedule.

Abstract: A method and system for adaptively monitoring a communication link of a wireless sensor network, which includes measuring a quality of the communications link at a beginning of the monitoring period and at an end of the monitoring period, decreasing the monitoring period if a change in the quality of the communication link measured at the beginning and end of the monitoring period exceeds a predefined threshold value, and increasing the monitoring period if the measured quality is essentially the same at the beginning and end of the monitoring period.

Abstract: A method of reducing an energy consumption of a wireless network, the method including periodically entering a sleep mode by a receiver node, broadcasting a signal simultaneously across a wide band frequency range, upon waking up from the sleep mode, listening by the receiver node to only a first narrow part of the wide band frequency range, the receiver node subsequently either returning to sleep if a signal strength of the broadcasted signal is less than a predefined signal strength threshold, or staying awake for an additional period of time if the signal strength of the broadcasted signal is greater than the predefined signal strength threshold.

Abstract: A method and system for determining a location of at least one stationary node of a wireless network, which includes providing a predetermined path within a geographic space of the wireless network, prior to localization, moving a mobile node along the predetermined path, measuring a network parameter with respect to the mobile node as it moves along the predetermined path, and performing a localization scheme to estimate the location of the at least one stationary node using the measured network parameter.

Abstract: Embodiments of a link assessment and frequency monitoring system for use in wireless sensor networks are described. In one embodiment, each frequency utilized by links coupling two or more nodes in the network is sampled to determine a noise measure for each frequency. A correlation measure based on the distance between the noise measures for each pair of frequencies is determined. The frequencies are then clustered into a number of groups of frequencies based on the correlation measure between each pair of frequencies, such that the number of groups is less than the total number of frequencies. A representative frequency for each group of frequencies is selected, and a link quality assessment for each pair of nodes in the network is performed for the representative frequency of each group of frequencies.

Abstract: Network node control is described that includes node wakeup scheduling that reduces the energy consumption of levels of nodes and reduces the delay of information transfer through the network. The node wakeup scheduling includes a crossed ladder pattern that combines two wakeups in one level. The node wakeup scheduling also includes an adaptive version of the crossed ladder pattern that changes the wakeup patterns of the crossed ladder over time to provide uniform energy savings. The network node control also includes the use of multiple trees to transfer information through a network. This multi-parent node assignment assigns multiple parents with different wakeup schedules to each node in the network. This multi-parent assignment reduces the delay in transmission of information through the network and also increases energy efficiency in the nodes.

Abstract: A technique for determining an arbitrary delay in a source code word propagated over a channel that introduces the arbitrary delay in the source code word to produce a received code word. The technique is based upon a multiple-shift algorithm to determine the delay by a coarse synchronization process to locate synchronization as contained within a composite code pattern, and a fine synchronization process to pinpoint the delay by examining shifts in the source code word used to form the composite code pattern.

Abstract: A technique for determining an arbitrary delay in a source code word propagated over a channel that introduces the arbitrary delay in the source code word to produce a received code word. The technique is based upon a multiple-shift algorithm to determine the delay by a coarse synchronization process to locate, synchronization as contained within a composite code pattern, and a fine synchronization process to pinpoint the delay by examining shifts in the source code word used to form the composite code pattern.