# US 12,119,999 B2 · Routing protocol method for underwater acoustic sensor networks based on layering and source location privacy

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,119,999 B2
- Document ID: US12119999B2
- Status: Granted
- Kind: B2
- Application number: 18/516,741
- Filed: 2023-11-21
- Published: 2024-03-28
- Granted: 2024-10-15
- Earliest claimed: 2023-03-20
- Assignees: Qinghai Normal University
- Applicants: Qinghai Normal University
- Inventors: Xiujuan Du; Xiaojing Tian
- Web page: https://patentgrep.com/patent/US12119999B2

## CPC

- H04L 41/12: Discovery or management of network topologies
- H04B 11/00: Transmission systems employing ultrasonic, sonic or infrasonic waves
- H04B 13/00: Transmission systems characterised by the medium used for transmission, not provided for in groups H04B3/00 - H04B11/00
- H04L 67/12: specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
- Y02D 30/70: in wireless communication networks
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04B: TRANSMISSION
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

A routing protocol method for Underwater Acoustic Sensor Networks (UASNs) based on layering and source location privacy (SLP) is provided. (1) A proxy area is selected randomly by a source node. (2) A packet is delivered from the source node to the proxy area through a forwarding probability-based multipath routing algorithm, and a layer-based priority is given to candidate neighbor nodes to alleviate a long detour problem. (3) A proxy node in the proxy area is selected randomly. (4) The packet is delivered from the proxy node to a sink node through the forwarding probability-based multipath routing algorithm. (5) Steps (1) to (4) are repeated until the source node is changed or an adversary finds a position of the source node.

## Claims

### Claim 1

A routing protocol method for underwater acoustic sensor networks (UASNs) based on layering and source location privacy (LSLP) s, comprising:
selecting randomly a proxy area by a source node;
delivering a packet from the source node to the proxy area through a forwarding probability-based multipath routing algorithm; and giving a layer-based priority to candidate neighbor nodes to alleviate a long detour problem;
selecting randomly a proxy node in the proxy area;
delivering the packet from the proxy node to a sink node through the forwarding probability-based multipath routing algorithm; and
repeating the previous steps;
wherein the step of selecting randomly the proxy node comprises:
(a) establishing a three-dimensional (3D) coordinate system with the sink node as a center node; making position information of the sink node public across a network; and dividing a 3D underwater space into four quadrants based on the 3D coordinate system;
(b) converting position information of an underwater node into a 3D coordinate centered on the sink node during a network initialization process;
(c) assuming that a layer of the source node is Ls, such that a layer of the proxy area is expressed as:
Lp=INT(Ls/2);
wherein Lp is the layer of the proxy area; and the proxy area contains all nodes in the layer Lp;
(d) dividing the proxy area into a first subarea, a second subarea, a third subarea, and a fourth subarea by the 3D coordinate system;
wherein if the source node is in one of the four quadrants, proxy areas in the other three of the four quadrants become candidate proxy areas; and a random number Q is set in a range from 0 to 3, and a target proxy area is selected according to a value of the random number Q; and
(e) after the packet is delivered from the source node to a first node in the target proxy area, randomly selecting the number of hops of the packet in the proxy area based on the random number Q, wherein a node reached by a last hop is the proxy node.

### Claim 2 (depends on 1)

The routing protocol method of claim 1, wherein the forwarding probability-based multipath routing algorithm is performed through steps of:
selecting, by a sending node, neighbor nodes whose layers are not greater than a layer of the sending node as the candidate neighbor nodes; and
selecting, by the sending node, a best next hop by calculating a forwarding probability of the candidate neighbor nodes; wherein the forwarding probability depends on a node density and a residual energy of the candidate neighbor node;
a forwarding probability P(i,j) of a candidate neighbor node j of a sending node i is expressed as:
P(i,j)=αe(j)+βd(j);
wherein α and β are weight coefficients, and α+β=1; d(j) represents a node density of the candidate neighbor node j; e(j) represents a ratio of a residual energy ER(j) of the candidate neighbor node j to an initial energy Einit of the candidate neighbor node j, and is expressed as:
e
⁡
(
j
)
=
E
R
(
j
)
E
init
;
the node density of the candidate neighbor node j is expressed as:
d
⁡
(
j
)
=
❘
"\[LeftBracketingBar]"
Nc
⁡
(
j
)
❘
"\[RightBracketingBar]"
∑
x
=
0
❘
"\[LeftBracketingBar]"
Nc
⁡
(
i
)
❘
"\[RightBracketingBar]"
❘
"\[LeftBracketingBar]"
Nc
⁡
(
x
)
❘
"\[RightBracketingBar]"
;
wherein Nc(j) represents a set of candidate nodes of the candidate node j; |Nc(j)| represents the number of the candidate nodes of the candidate node j; and
∑
x
=
0
❘
"\[LeftBracketingBar]"
Nc
⁡
(
i
)
❘
"\[RightBracketingBar]"
❘
"\[LeftBracketingBar]"
Nc
⁡
(
x
)
❘
"\[RightBracketingBar]"
represents the number of candidate neighbor nodes of all candidate neighbor nodes of the sending node i.

### Claim 3 (depends on 1)

The routing protocol method of claim 1, further comprising:
screening a candidate neighbor node of a sending node that is close to the proxy area through the following steps:
(A) setting a coordinate of a sending node A as (xs, ys, zs); selecting a coordinate of a sphere center O as (a,b,c); wherein the sphere center O is a coordinate point of the sending node A closest to a quadrant in which the proxy area is located;
(B) calculating a sphere radius R; wherein the sphere radius R is a maximum of a distance Rmin and a communication radius Rc; and the distance Rmin represents a distance between the sending node A and the sphere center O, expressed as:
Rmin=sqrt((a−xs){circumflex over ( )}2+(b−ys){circumflex over ( )}2+(c−zs){circumflex over ( )}2);
the sphere radius R is expressed as:
R=max(Rmin,Rc);
(C) screening the candidate neighbor node close to the proxy area; assuming that a set of the candidate neighbor node close to the proxy area is V, the sending node A has i candidate neighbor nodes, and coordinates of the i candidate neighbor nodes are expressed as (xi, yi, zi); wherein a node whose distance from the sphere center O is less than or equal to the sphere radius R is the candidate neighbor node of the sending node A close to the proxy area; and the set V is expressed as:
V={(xi,yi,zi)|sqrt((a−xi){circumflex over ( )}2+(b−yi){circumflex over ( )}2+(c−zi){circumflex over ( )}2)<=R}.

### Claim 4 (depends on 3)

The routing protocol method of claim 3, wherein the layer-based priority comprises:
Priority 1: the sending node preferentially selects the candidate neighbor node that is close to the proxy area; and
Priority 2: compared to a layer of the sending node, the candidate neighbor node with a smaller layer is preferentially selected;
wherein the sending node first selects candidate neighbor nodes that satisfy the priority 1, finds candidate neighbor nodes that satisfy the priority 2 from the candidate neighbor nodes that satisfy the priority 1, and selects a node with the highest forwarding probability from the candidate neighbor nodes that satisfy both the priority 1 and the priority 2 as a best next hop according to the forwarding probability-based multipath routing algorithm.