# US 2021/0243674 A1 · Routing method and device of mobile ad-hoc networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0243674 A1 - Document ID: US20210243674A1 - Status: Published application - Kind: A1 - Application number: 16/777,388 - Filed: 2020-01-30 - Published: 2021-08-05 - Earliest claimed: 2020-01-30 - Assignees: Mage Networks Inc. - Applicants: Mage Networks Inc. - Inventors: Mohamed Ammar Al Masri; Sayed-Amr El-Hamamsy; Ahmed N. Zaki - Web page: https://patentgrep.com/patent/US20210243674A1 ## CPC - H04W 40/12: based on transmission quality or channel quality - H04W 40/248: {Connectivity information update} - H04W 40/244: {using a network of reference devices, e.g. beaconing} - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A network construction method, a routing method and device of mobile ad-hoc networks are provided. The mobile ad-hoc network includes a plurality of nodes, each node communicating with its neighbors via communication links. The routing method comprises the following steps: each node identifying a link quality with each of its neighbors by providing marks based on a hysteresis-based link quality marking mechanism; each node identifying a link operationality with each of its neighbors by evaluating a score calculated from the marks; and each node reconstructing routes with its neighbors by filtering route construction messages related to the link operationality of the neighbors. ## Claims ### Claim 1 A routing method of a mobile ad-hoc network, the mobile ad-hoc network including a plurality of nodes, each node communicating with at least one neighbor via at least one communication link, the method comprising: each node transmitting an advertisement; each node identifying a link quality with each of the at least one neighbor providing at least one mark based on a link quality metric; each node identifying a link operationality with each of the at least one neighbor by evaluating a score calculated from the at least one mark; and each node reconstructing at least one route with the at least one neighbor by filtering at least one route construction message related to the link operationality of the at least one neighbor. ### Claim 2 (depends on 1) The routing method according to claim 1, wherein the link quality metric is hysteresis-based. ### Claim 3 (depends on 1) The routing method according to claim 1, wherein the step of identifying the link quality further comprises: comparing the link quality metric received from the advertisement of the at least one neighbor with a high threshold and a low threshold. ### Claim 4 (depends on 3) The routing method according to claim 3, wherein the link quality metric comprises: marking the link quality as high when the link quality metric exceeds the high threshold; marking the link quality as low when the link quality metric falls below the low threshold; marking the link quality as high when the link quality metric falls below the high threshold, and before the link quality metric falls below the low threshold; marking the link quality as low when the link quality metric rises above the low threshold, and before the link quality metric exceeds the high threshold; and marking the link quality as low if a timeout timer for receiving the advertisement expires before receiving a new advertisement from the at least one neighbor. ### Claim 5 (depends on 3) The routing method according to claim 3, wherein the link quality metric is selected from at least one of: a received signal strength indicator (RSSI), a Bit Error Rate (BER), a Signal to Noise Ratio (SNR), a Signal to Noise and Interference Ratio (SNIR), and any combination thereof. ### Claim 6 (depends on 4) The routing method according to claim 4, wherein the low threshold is selected to be higher than a sensitivity of a recipient node. ### Claim 7 (depends on 5) The routing method according to claim 5, wherein the step of identifying link operationality further comprises: comparing the score with a score-operational (SOP) criterion and with a Score-Non-Operational (SNOP) criterion. ### Claim 8 (depends on 7) The routing method according to claim 7, wherein the step of identifying link operationality further comprises: identifying a link-from-neighbor operationality and a link-to-neighbor operationality. ### Claim 9 (depends on 8) The routing method according to claim 8, wherein the step of identifying the link-from-neighbor operationality comprises: marking the link-from-neighbor as directionally Operational (OP) when the score meets the SOP criterion; marking the link-from-neighbor as directionally Non-Operational (NOP) when the score meets the SNOP criterion; and keeping the link-from-neighbor as a previous status when the score does not meet the SOP criterion and the SNOP criterion. ### Claim 10 (depends on 9) The routing method according to claim 9, wherein the step of identifying the link-to-neighbor operationality comprises: marking the link-to-neighbor as directionally NOP when each node does not find each node's own IP address in the advertisement; marking the link-to-neighbor as Going-Non-Operational (GNOP) when the score to the at least one neighbor meets the SNOP criterion when each node finds each node's own IP address in the advertisement; and marking the link-to-neighbor as directionally OP when the score to the at least one neighbor does not meet the SNOP criterion when each node finds each node's own IP address in the advertisement. ### Claim 11 (depends on 9) The routing method according to claim 9, wherein the score to the at least one neighbor is calculated based on the link quality metric of an advertised last j marks. ### Claim 12 (depends on 10) The routing method according to claim 10, wherein the score to the at least one neighbor is calculated based on the link quality metric of an advertised last j−1 marks and assuming that the jth mark has a low-quality. ### Claim 13 (depends on 8) The routing method according to claim 8, wherein a link-with-neighbor is marked as bidirectionally OP when both link-from-neighbor and link-to-neighbor meet the OP criterion. ### Claim 14 (depends on 8) The routing method according to claim 8, further comprises: broadcasting a Route Failure Message (RFM) when a link-with-neighbor is marked as NOP. ### Claim 15 (depends on 8) The routing method according to claim 8, wherein the step of identifying link operationality further comprises: determining the link-from-neighbor operationality and the link-to-neighbor operationality under data packet transmission failure. ### Claim 16 (depends on 15) The routing method according to claim 15, wherein the step of determining the link-from-neighbor operationality and the link-to-neighbor operationality under data packet transmission failure further comprises: increasing a packet retransmission counter by 1 when a data packet transmission has failed; increasing a dropped packet counter by 1 when the data packet retransmission counter exceeds a predetermined number of retransmission tries, R; and marking both the link-to-neighbor and the link-from-neighbor as NOP when the dropped packet counter exceeds a predetermined number of dropped packets, N. ### Claim 17 (depends on 16) The routing method according to claim 16, further comprise: retransmitting data packet when the data packet retransmission counter is below the predetermined number of retransmission tries, R. ### Claim 18 (depends on 16) The routing method according to claim 16, further comprise: resetting the packet retransmission counter, and retransmitting data packet when the dropped packet counter is below the predetermined number of dropped packets, N. ### Claim 19 (depends on 14) The routing method according to claim 14, wherein the step of filtering route construction messages comprises responding to a Seek Route Message (SRM) from the at least one neighbor and responding to the RFM from the at least one neighbor. ### Claim 20 (depends on 19) The routing method according to claim 19, wherein responding to SRM comprises: discarding the received SRM when each node receives an SRM over a NOP link-with-neighbor; and discarding the received SRM if the link-to-neighbor is marked as GNOP when each node receives an SRM over an OP link-with-neighbor. ### Claim 21 (depends on 18) The routing method according to claim 18, wherein responding to the RFM comprises: discarding the received RFM when each node receives the RFM over the NOP link-with-neighbor. ### Claim 22 (depends on 19) The routing method according to claim 19, wherein responding to the RFM comprises: when each node receives the RFM over an OP link-with-neighbor, marking the link-to-neighbor as NOP if the RFM has each node's own IP address among a list of non-reachable destinations; and invalidating the route using that link. ### Claim 23 (depends on 1) A mobile device comprising a non-transitory computer readable medium storing instructions to cause the mobile device to execute the method of claim 1. ### Claim 24 (depends on 1) A mobile ad-hoc network comprising a plurality of nodes, each node communicating with the at least one neighbor according to the routing method of claim 1. ### Claim 25 A mobile ad-hoc network comprising: a plurality of point of attachment (PoA) forming a coverage area, each PoA configured to provide a communication link for a mobile node; each PoA identifying a link quality metric for the communication link with the mobile node; the plurality of PoA located such that: when the mobile node is within the coverage area, the mobile node has at least one operational link with at least one PoA of the plurality of PoA; when the mobile node moves within the area of coverage, the at least one operational link is degrading and the communication link with at least one other PoA is improving; and when the mobile node has only one operational link, a travel time for the mobile node to travel between the PoA with the operational link to the at least one other PoA is less than a time for the mobile node to mark the operational link as non-operational and select the communication link as operational. ### Claim 26 (depends on 25) The mobile ad-hoc network according to claim 25, wherein the link quality metric is hysteresis-based. ### Claim 27 (depends on 25) The mobile ad-hoc network according to claim 25, each PoA compares the link quality metric received from an advertisement with a high threshold and a low threshold. ### Claim 28 (depends on 27) The mobile ad-hoc network according to claim 27, wherein the link quality metric comprises: marking a link quality as high when the link quality metric exceeds the high threshold; marking the link quality as low when the link quality metric falls below the low threshold; marking the link quality as high when the link quality metric falls below the high threshold, and before the link quality metric falls below the low threshold; marking the link quality as low when the link quality metric rises above the low threshold, and before the link quality metric exceeds the high threshold; and marking the link quality as low if a timeout timer for receiving the advertisement expires before receiving a new advertisement. ### Claim 29 (depends on 25) The mobile ad-hoc network according to claim 25, wherein the link quality metric is selected from at least one of: a received signal strength indicator (RSSI), a Bit Error Rate (BER), a Signal to Noise Ratio (SNR), a Signal to Noise and Interference Ratio (SNIR), and any combination thereof. ### Claim 30 (depends on 27) The mobile ad-hoc network according to claim 27, wherein the low threshold is selected to be higher than a sensitivity of the mobile node. ### Claim 31 (depends on 27) The mobile ad-hoc network according to claim 27, wherein the at least one operational link is identified by: comparing a score with a score-operational (SOP) criterion and with a Score-Non-Operational (SNOP) criterion. ### Claim 32 (depends on 31) The mobile ad-hoc network according to claim 31, wherein the at least one operational link is identified by: identifying a link-from-neighbor operationality and a link-to-neighbor operationality. ### Claim 33 (depends on 32) The mobile ad-hoc network according to claim 32, wherein the link-from-neighbor operationality comprises: marking the link-from-neighbor as directionally Operational (OP) when the score meets the SOP criterion; marking the link-from-neighbor as directionally Non-Operational (NOP) when the score meets the SNOP criterion; and keeping the link-from-neighbor as a previous status when the score does not meet the SOP criterion and the SNOP criterion. ### Claim 34 (depends on 33) The mobile ad-hoc network according to claim 33, wherein the link-to-neighbor operationality comprises: marking the link-to-neighbor as directionally NOP when each PoA does not find each PoA's own IP address in the advertisement; marking the link-to-neighbor as Going-Non-Operational (GNOP) when the score to the at least one neighbor meets the SNOP criterion when each PoA finds each PoA's own IP address in the advertisement; and marking the link-to-neighbor as directionally OP when the score to the at least one neighbor does not meet the SNOP criterion when each PoA finds each PoA's own IP address in the advertisement.