Itron Gmbh

E.f. Johnson Company

Howard N Brace

Keith W Barnes

Thomas F Uhling

Imad Jamil

Donald R Bauman

Philip A Keefer

Michael E Mihelich

Fabrice Monier

Kalvinder Pal Singh

Garten Haeska

One embodiment of the present invention sets forth a technique for communicating within a network. The technique includes receiving, by a first node in a mesh network at a first receive time, a first beacon from a second node in the mesh network, the first beacon including a first network time associated with the second node; determining, by the first node, a first transmission time of a first unicast message to the second node based on (a) the first receive time, (b) the first network time, and (c) a unicast interval between consecutive unicast listening times on the second node; and transmitting, by the first node, the first unicast message to the second node at the first transmission time.

Unicast transmissions in mesh network nodes

One embodiment of the present disclosure sets forth a technique for resolving beaconing conflicts within a network. The technique includes detecting, by a first node in a network, a first scheduling conflict between a first time when a first beacon is to be transmitted from the first node and a first listening window when a second beacon is expected to be received from a second node in the network; determining, by the first node in response to detecting the first scheduling conflict and based on an expected transmission time for the second beacon and a position of the second node in the network, an alternate listening window during which to listen for a third beacon from the second node; and listening, by the first node, for the third beacon from the second node during the alternate listening window.

Resolving beacon transmission and receipt conflicts in mesh network nodes

A network system includes a main network implementing a conventional network protocol and a subtree of battery-powered nodes implementing a custom network protocol. The main network and the subtree are managed according to different subtree parameters. When a root node receives a request by a battery-powered node to join the subtree, the root node determines whether to allow the battery-powered node to join based on the subtree parameters for the subtree before sending a response to the battery-powered node.

Network protocol for battery powered devices within a wireless network

Techniques for performing time synchronization within a network include a method comprising: determining, by a first node, a receive time at which a periodic beacon from a second node is expected to be received based on timing information associated with the second node; determining, by the first node, a first listening window for the periodic beacon based on the receive time and one or more of a drift uncertainty associated with an anticipated drift in a correction of a timing error between the first node and the second node or a jitter uncertainty associated with timing jitter in the first node or the second node; and listening, by the first node, for the periodic beacon during the first listening window.

Time synchronization of mesh network nodes

One embodiment of the present invention sets forth a technique for performing time synchronization within a network. The technique includes detecting a first scheduling conflict between a first transmission time associated with a first periodic beacon from a first node in the network and a second transmission time associated with a second periodic beacon from a second node in the network. The technique also includes determining a first alternate transmission time associated with the first periodic beacon based on a position of the first node in the network and the first transmission time. The technique further includes transmitting the first periodic beacon at the first transmission time, and transmitting an alternate periodic beacon at the first alternate transmission time.

Resolving beacon transmission conflicts in mesh network nodes

One embodiment of the present invention sets forth a technique for performing time synchronization within a network. The technique includes detecting a first scheduling conflict between a first transmission time associated with a first periodic beacon from a first node in the network and a first listening window associated with receiving a second periodic beacon from a second node in the network. The technique also includes determining a first alternate transmission time for the second periodic beacon based on a second transmission time associated with the second periodic beacon and a position of the second node in the network and calculating a second listening window associated with transmission of the second periodic beacon from the second node at the first alternate transmission time. The technique further includes listening for the second periodic beacon during the second listening window.

A battery-powered device (BPD) node compresses certificate chains to generate compressed certificate chains. The BPD node includes a compression dictionary that indexes various data entries that occur across many certificate chains and/or repeat within a particular certificate chain. The BPD node compresses a given certificate chain by replacing data entries within the given certificate chain with indices to corresponding data entries in the compression dictionary. The indices are smaller in size than the corresponding data entries. A neighboring BPD node also includes the compression dictionary and decompresses a compressed certificate chain by replacing indices included in the compressed certificate chain with the indexed data entries stored in the compression dictionary. Performing certificate exchanges with compressed certificate chains reduces the amount of limited battery power that is depleted during certificate exchanges, thereby extending BPD node operational lifetime and helping to prevent the need for premature battery replacement.

Certificate chain compression to extend node operational lifetime

One embodiment of the present invention sets forth a technique for communicating within a network. The technique includes receiving, from a first node in the network and at a first receive time, a first periodic beacon that includes a first network time associated with the first node. The technique also includes determining a first transmission time of a first unicast message to the first node based on the first network time and a unicast interval between consecutive unicast listening times on the first node. The technique further includes transmitting the first unicast message to the first node at the first transmission time.

One embodiment of the present invention sets forth a technique for performing time synchronization within a network. The technique includes receiving, from a first node in the network and at a first receive time, a first periodic beacon that includes a first network time associated with the first node. The technique also includes determining a second receive time at which a second periodic beacon from the first node is to be received based on the first network time and the first receive time. The technique further includes calculating a first listening window for the second periodic beacon based on the second receive time, a first jitter uncertainty, and a first drift uncertainty, and listening for the second periodic beacon during the first listening window.

A network system includes a main network implementing a conventional network protocol and a BPD subtree implementing a custom network protocol. The main network comprises a plurality of MPD nodes, the conventional network protocol being configured for MPD nodes. The BPD subtree comprises a plurality of BPD nodes, the custom network protocol being configured for BPD nodes. The custom network protocol defines smaller and simpler subtrees relative to the conventional network protocol. As a result, the custom network protocol defines less complex functions relative to the conventional network protocol, including functions for discovery, messaging, and loop management. A root node of the BPD subtree is connected with an MPD node of the main network and one or more descendant nodes of the BPD subtree. The root node implements the conventional network protocol and the custom network protocol.

A method and apparatus for providing priority access for users in a transmission trunked communication system, including a plurality of distributive radio network terminal (RNT) switches and a unique signaling protocol and a switching protocol especially adapted for communication of control signals in the subaudio band for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities.

Priority system for a wide area transmission trunked communication system

A land mobile transmission trunked communication system is provided with a unique switching protocol arrangement among repeaters that are networked to one or more external communication networks. The land mobile transmission trunked communication system includes a plurality of transceivers for transmitting and receiving transmission trunked radio communications over one or more radio channels. The transceivers communicate with a selected one of a plurality of repeaters to establish transmission trunked radio communications on a preassigned radio channel. The unique switching protocol arangement includes a switch that is operably connected to each repeater and selectively communicates information signals between a repeater and an external communication network. A bus system is operably connected to each repeater and to the switch for communicating control signals among all of the repeaters and the switch. The control signals include an indication for each repeater which is controlled by that repeater and by the switch as to free channel availability. Because the mechanism for controlling indications of free channel availability is operationally separate from the switch, the repeaters continue to provide transmission trunked communications to the transceivers in the event of a failure of the switch.

Method and apparatus for a distributive wide area network for a land

A method and apparatus for distributively interconnecting a plurality of land mobile trunked transmission communication systems into a wide area network includes a plurality of distributive radio network terminal (RNT) switch and a unique signaling protocol and a switching protocol especially adapted for communication of control signals in the subaudio band for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities.

Method and apparatus for a remote network switch for a land mobile

A land mobile transmission trunked communication system is provided with an enhanced control signal protocol. The land mobile transmission trunked communication system includes a plurality of transceivers for transmitting and receiving transmission trunked radio communications over one or more radio channels. The transmission trunked radio communications comprises an information signal having either voice information, data information, or both, and a control signal. The transceivers communicate with a selected one of a plurality of repeaters to establish transmission trunked radio communications on one of the preassigned set of the radio channels between the repeater and one or more transceivers. The enhanced signaling protocol and switching protocol are especially adapted for communicating control signals in the subaudio band to interconnect a plurality of transmission trunked communication systems into a wide area network. The enhanced switching and signaling protocol provide an expanded feature set of radio communication capabilities.

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Waseca, MN, United States of America

Howard N Brace