摘要:
A hybrid communication network for a transportation safety system includes a fixed wired nodes and mobile wireless nodes. Because the wired nodes operate independently packets transmitted by the wired nodes to the wireless nodes need to be synchronized. A downlink travel time for downlink packets traveling from a controller to the wireless nodes is determined. Then, the controller schedules downlink data intervals (DDI) based on the downlink travel time; and transmits downlink packets to the wireless nodes during the DDI, such that a latency requirement of the transportation safety system is satisfied.
摘要:
A hybrid communication network for a transportation safety system includes a wired network including a set of fixed nodes. Each fixed node includes a wired interface for connecting the fixed node to the wired network and at least one wireless interface. The set of fixed nodes further includes a head node at a first end of the wired network connected to a controller, a terminal node at a second end of the wired network, and a set of relay nodes arranged between the head node and the terminal node. A wireless network includes a set of mobile nodes and a set of fixed nodes connected to the wired network. Each mobile node includes at least one of the wireless interfaces, and each mobile node is arranged in a moveable car.
摘要:
In a network for a safety system in a transportation system, the transportation system includes a shaft and a car arranged in the shaft. A first wall node is at a first end of the shaft and a second wall node is at a second end of the shaft to communicate safety messages with the car. Each wall node includes at least one wireless transceiver connected to one or more antennas. Each car in the shaft includes at least two wireless transceiver connected to one or more antennas, wherein the first transceiver of the car uses a first frequency and the second transceiver of the car uses a second frequency to communicate each safety messages in duplicate. A wired backbone connects the set of wall nodes to a controller of the safety system of the transportation system.
摘要:
A hybrid communication network for a transportation safety system includes a fixed wired nodes and mobile wireless nodes. Because the wired nodes operate independently packets transmitted by the wired nodes to the wireless nodes need to be synchronized. A downlink travel time for downlink packets traveling from a controller to the wireless nodes is determined. Then, the controller schedules downlink data intervals (DDI) based on the downlink travel time; and transmits downlink packets to the wireless nodes during the DDI, such that a latency requirement of the transportation safety system is satisfied.
摘要:
In a network for a safety system in a transportation system, the transportation system includes a shaft and a car arranged in the shaft. A first wall node is at a first end of the shaft and a second wall node is at a second end of the shaft to communicate safety messages with the car. Each wall node includes at least one wireless transceiver connected to one or more antennas. Each car in the shaft includes at least two wireless transceiver connected to one or more antennas, wherein the first transceiver of the car uses a first frequency and the second transceiver of the car uses a second frequency to communicate each safety messages in duplicate. A wired backbone connects the set of wall nodes to a controller of the safety system of the transportation system.
摘要:
A method for transmitting information in a communication network of multiple nodes, in which information transmission is partitioned into successive superframes, and in which each superframe is partitioned into a beacon period followed by a data period, which may consist of a contention free period (CFP), and each beacon period and CFP of the data period is partitioned into timeslots. The method includes allocating to at least a first node of the multiple nodes a designated timeslot in which to transmit data in at least one of a plurality of superframes, and allocating to at least a second node of the multiple nodes the same designated timeslot in which to transmit information during at least one subsequent superframe.
摘要:
A method for transmitting information in a communication network of multiple nodes, in which information transmission is partitioned into successive superframes, and in which each superframe is partitioned into a beacon period followed by a data period, which may consist of a contention free period (CFP), and each beacon period and CFP of the data period is partitioned into timeslots. The method includes allocating to at least a first node of the multiple nodes a designated timeslot in which to transmit data in at least one of a plurality of superframes, and allocating to at least a second node of the multiple nodes the same designated timeslot in which to transmit information during at least one subsequent superframe.
摘要:
A method and system broadcasts an alert packet in a wireless multi-hop network of nodes. An event is sensed in a source node of the network, and an alert packet is broadcast in response to sensing the event. The alert packet is received in a set of candidate nodes within a broadcast range of the source node. Each candidate node infers a distance between the candidate node and the source node based on a receive power of the received alert packet, and determines a priority for rebroadcasting the alert packet, wherein the priority is based on the distance to minimizing a probability of collisions while rebroadcasting the alert packet and extend a range of the rebroadcasting.
摘要:
A method and system broadcasts an alert packet in a wireless multi-hop network of nodes. An event is sensed in a source node of the network, and an alert packet is broadcast in response to sensing the event. The alert packet is received in a set of candidate nodes within a broadcast range of the source node. Each candidate node infers a distance between the candidate node and the source node based on a receive power of the received alert packet, and determines a priority for rebroadcasting the alert packet, wherein the priority is based on the distance to minimizing a probability of collisions while rebroadcasting the alert packet and extend a range of the rebroadcasting.
摘要:
A method performs handover of a mobile station (MS from a current base station (BSC) connected to a target base station (BST) via a backbone in a Worldwide interoperability for Microwave Access (WiMAX) mobile communication network. The MS, before handover, transmits a Connection Identifier Request (CID-REQ) to the BST via the BSC, and receiving a Connection Identifier Response (CID-RSP) from the BST via the BSC. The MS, before handover, transmits a Subscriber Station (SS) Basic Capability Request (SBC-REQ), and receives a SS Basic Capability Response (SBC-RSP) from the BST via the BSC. Then, the MS transmits a Ranging Request (RNG-REQ) to the BST, and receives a Ranging Response (RNG-RSP) from the BST. During the handover, the MS transmits a Registration Request (REG-REQ) to the BST, and receives a Registration Response from the BST to establish the connection between the MS and the BST.