摘要:
A source node estimates not only the schedule time offset of the destination node but also the clock drift of the destination node. In this way, the source node may choose very accurately the transmission start time of an information packet to this destination node so that typically only one very short preamble needs to be transmitted. The estimation of time offset and clock drift between two nodes is achieved through tone or more previous transmissions between these two nodes, in particular, information relating to these parameters is transmitted from the destination node to the source node in reply to a preamble transmitted by the source node to the destination node.
摘要:
A wireless network includes permanently powered routing nodes and intermittently operating routing nodes. A polling procedure is used for transferring routing and data information packets from a permanently powered routing node to an intermittently operating routing node. In particular, when the permanently powered routing node has to transmit an information packet to the intermittently operating routing node, it stores the information packet in a memory; it waits until the intermittently operating routing node is able to receive information packets; and then it transmits the information packet to the intermittently operating routing node, and when the intermittently operating routing node has to transmit an information packet to the permanently powered routing node, it transmits immediately the information packet to the permanently powered routing node.
摘要:
A wireless network includes permanently powered routing nodes and intermittently operating routing nodes. A polling procedure is used for transferring routing and data information packets from a permanently powered routing node to an intermittently operating routing node. In particular, when the permanently powered routing node has to transmit an information packet to the intermittently operating routing node, it stores the information packet in a memory; it waits until the intermittently operating routing node is able to receive information packets; and then it transmits the information packet to the intermittently operating routing node, and when the intermittently operating routing node has to transmit an information packet to the permanently powered routing node, it transmits immediately the information packet to the permanently powered routing node.
摘要:
A source node estimates not only the schedule time offset of the destination node but also the clock drift of the destination node. In this way, the source node may choose very accurately the transmission start time of an information packet to this destination node so that typically only one very short preamble needs to be transmitted. The estimation of time offset and clock drift between two nodes is achieved through tone or more previous transmissions between these two nodes, in particular, information relating to these parameters is transmitted from the destination node to the source node in reply to a preamble transmitted by the source node to the destination node.
摘要:
To reduce energy consumption in a duty-cycled asynchronous wireless communication network values of operation parameters, i.e. duration of the awake interval and duration of the sleep interval, of routing nodes of the network are determined and set. The network is partitioned into clusters so that each cluster comprises one cluster-head node. The energy consumption of a cluster is a function of the probability of busy channel when nodes of the cluster attempt transmission, the probability of communication collision during transmission, the duration of the awake interval and the duration of the sleep interval of its cluster-head node. Reduction of the energy consumption is carried out under predetermined values of the probability of busy channel and of the probability of communication collision and under predetermined constraint for the probability of successful transfer of data packets within the cluster and for the average delay of transfer of data packets within the cluster.
摘要:
A power efficient system architecture that exploits the characteristics of sensor networks in order to decrease the power consumption in the network. The primary characteristic of sensor networks is that the destination of all the data packets in the network is a central data collector and this central data collector, which is usually denoted as access point (AP), has unlimited transmission power and energy whereas the sensor nodes have limited battery energy and transmission power. The system uses the AP to directly synchronize and explicitly schedule the nodes' transmissions over Time Division Multiple Access (TDMA) time slots.
摘要:
Wireless transmission from sensor devices included in tires is coordinated by a receiving unit associated with the tire, or transmission coordinator. In more detail, every sensor device is made aware of an overall time window available for transmission, and based on at least this information, it calculates a dedicated timeslot for the transmission of its data within such time window. This coordinated transmission makes possible a strong reduction of the probability of collisions and transmission errors, and reduces the number of transmissions, so as to comply with the limited power resources available at each sensor device.
摘要:
A power efficient system architecture that exploits the characteristics of sensor networks in order to decrease the power consumption in the network. The primary characteristic of sensor networks is that the destination of all the data packets in the network is a central data collector and this central data collector, which is usually denoted as access point (AP), has unlimited transmission power and energy whereas the sensor nodes have limited battery energy and transmission power. The system uses the AP to directly synchronize and explicitly schedule the nodes' transmissions over Time Division Multiple Access (TDMA) time slots.