Underwater multi-hop communications network

Patent metadata

Field	Value
Publication number	US-2016134433-A1
Application number	US-201414898440-A
Country	US
Kind code	A1
Filing date	Jun 13, 2014
Priority date	Jun 14, 2013
Publication date	May 12, 2016
Grant date	—

Abstract

A multi-hop ad hoc communications network may allow optical communications between underwater nodes. Each node may be fitted with environmental sensors. Each node may collect data from the sensors and transmit the data to other nodes in the network according to a time division multiple access (TDMA) scheme. The data may propagate through a series of child and parent nodes to reach a master node. The master node may have a wired connection for power and data transfer.

First claim

What is claimed is:

1 . An apparatus, comprising:
a master node; and an ad hoc network comprising at least one remote node, each remote node comprising:
a power source;
a transmitter comprising a light source;
a receiver;
a sensor; and
a processor,
wherein the processor is configured to:
identify a communications path to the master node through at least one other remote node of the ad hoc network;
obtain data from the sensor;
receive, through the receiver, other sensor data from at least one other remote node of the ad hoc network;
relay, through the transmitter, the sensor data and the other sensor data to the master node according to a time division multiple access (TDMA) scheme along the communications path; and
dynamically reconfigure the communications path when the ad hoc network changes.

2 . The apparatus of claim 1 , in which the transmitter is a wireless transmitter.

3 . The apparatus of claim 1 , in which the communications path comprises a path to the master node through at least two neighboring remote nodes of the ad hoc network, and in which the processor is configured to relay the sensor data to the at least two neighboring remote nodes according to a point-to-multipoint scheme.

4 . The apparatus of claim 1 , in which the receiver comprises at least one of a photodiode, a phototransistor, a photomultiplier, a charge-coupled device (CCD), and a complimentary metal-oxide-semiconductor (CMOS) circuits.

5 . The apparatus of claim 1 , in which the processor of each of the plurality of remote nodes is further configured to receive a clock time at a start of a data collection cycle in the TDMA scheme.

6 . The apparatus of claim 5 , in which the processor of each of the plurality of remote nodes is further configured to activate a sleep mode at the end of the data collection cycle in the TDMA scheme.

7 . The apparatus of claim 1 , in which the master node is wired to a communications network and is wired to a power supply.

8 . The apparatus of claim 1 , in which the sensor comprises at least one of a temperature sensor, a pH sensor, a dissolved O 2 sensor, a backscatter sensor, a camera, an ambient light sensor, an autofluorescence sensor, an accelerometer, a conductivity sensor, and a pressure sensor.

9 . The apparatus of claim 1 , in which the light source comprises a 473-nanometer blue light emitting diode (LED).

10 . The apparatus of claim 1 , in which the master node comprises a photo-multiplier tube (PMT) configured to amplify light signals received from the light source of the at least one remote node.

11 . A method, comprising:
receiving, by a processor of a remote node of an ad hoc network, data from a sensor; identifying, by a processor, a communications path to a master node through at least one other remote node of the ad hoc network; receiving, by the processor, other sensor data from at least one other node of the ad hoc network; transmitting, through a transmitter of the remote node by the processor, the sensor data and the other sensor data through the communications path according to a time division multiple access (TDMA) scheme; and dynamically reconfiguring, by the processor, the communications path when the ad hoc network changes.

12 . The method of claim 11 , in which the step of transmitting comprises wirelessly transmitting through an optical interface.

13 . The method of claim 11 , in which the step of transmitting according to the TDMA scheme comprises identifying a time slot in a time frame corresponding to the remote node.

14 . The method of claim 11 , further comprising transmitting, through the transmitter, a clock time to at least one other node of the ad hoc network.

15 . The method of claim 11 , in which the step of identifying the communications path comprises:
seeding a tree with n 0 as the master node; populating the tree with n i nodes between the remote node and the master node; and tracing the communications path through at least one other node of the ad hoc network to the master node.

16 . The method of claim 15 , further comprising storing, at the remote node, information regarding the ad hoc network.

17 . The method of claim 16 , further comprising:
receiving, from at least one other remote node of the ad hoc network, the tree comprising information regarding a plurality of remote nodes in the ad hoc network; and propagating the tree from the remote node to at least one other remote node of the ad hoc network.

18 . The method of claim 16 , further comprising storing, at the remote node, level information regarding a number of hops from the remote node to the master node.

19 . The method of claim 11 , in which the sensor data comprises at least one of temperature data, pH data, dissolved O 2 data, backscatter data, and ambient light data.

20 . The method of claim 11 , further comprising transmitting, through the transmitter of the remote node, the sensor data and the other sensor data to a second at least one other remote node of the ad hoc network according to a point-to-multipoint scheme.

Assignees

• Univ Arizona State

Inventors

• Youngbull Cody
• Ganger David
• Mora Andres
• Richa Andrea
• Zhang Jin
• Zhou Chenyang
• Hu Xinhui

Classifications

• H04L45/48

  Routing tree calculation · CPC title

• H04W76/046

  Electricity · mapped topic

• H04L12/4035 Primary

  in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit (TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64) · CPC title

• H04W84/18

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title

• H04B7/2643

  using time-division multiple access [TDMA] (H04B7/2615, H04B7/2618 take precedence) · CPC title