Determining the (inner) boundary of a region
The algorithm starts with every mote broadcasting a message to its neighbors stating if it has detected the region. Every time a mote receives a message, it checks the received value with its own. If a mote detects it is within the region and receives a message from a neighbor that is not, it transitions into the BNDY state.
Code designed by Matt Duckham. Additional coding by Alan Both.
Copyright 2011, 2012 Matt Duckham
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License http://www.gnu.org/licenses/ for more details.
The formal specification procedure used for all the protocols on this site is based on the standard distributed systems approach of Nicola Santoro (see Santoro, N. Design and Analysis of Distributed Algorithms. Wiley, Hoboken, NJ. 2007.) For more details on the protocol specification style, please refer to the book accompanying book for this website, Decentralized Spatial Computing: Foundations of Geosensor Networks.
;; Copyright 2011, 2012 Matt Duckham ;; ;; This program is free software: you can redistribute it and/or modify ;; it under the terms of the GNU General Public License as published by ;; the Free Software Foundation, either version 3 of the License, or ;; (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public License ;; along with this program. If not, see <http://www.gnu.org/licenses/>. __includes["../gsn.nls" "../env.nls"] ;; Define a new breed of turtle called motes breed [motes mote] ;; Each mote can store the local variable s which is the sensed value. motes-own [s] ;; System setup and initialization to initialize make-single-region RegionSize ;; Create the region if NetworkStructure = "UDG" [create-udg] ;; Create UDG network if NetworkStructure = "GG" [create-udg create-gg] ;; Create GG network if NetworkStructure = "RNG" [create-udg create-rng] ;; Create RNG network ask motes [ ifelse [region] of patch-here = ["A"] [set s 1] ;; When region detected, s equals 1 [set s 0] ;; When region not detected, s equals 0 become "INIT" ;; Set all motes to state INIT ] end ;; Runs the boundary algorithm to go ask motes [ step ] mote_labels ;; Changes the labels of the motes based on the MoteLabel dropdown list tick end ;; ;; Mote protocols ;; ;; Step through the current state to step if state = "INIT" [ step_INIT stop ] if state = "IDLE" [ step_IDLE stop ] if state = "BNDY" [ step_BNDY stop ] end ;; Broadcast sensed value to neighbors. to step_INIT broadcast (list "PING" s) ;; Broadcast PING with sensed value become "IDLE" end ;; When a mote receives a message it determines if it's on the boundary of the region. to step_IDLE if has-message "PING" [ ;; Receiving PING let msg received "PING" let s' item 1 msg ;; Received sensed value if s' != s and s = 1 [ ;; Check if node is in the region, but adjacent to node outside become "BNDY" ] stop ] end ;; The BNDY state does not respond to messages. to step_BNDY end ;; Changing the labels of the motes based on the MoteLabel dropdown list to mote_labels ask motes [ if MoteLabel = "none" [set label ""] ;; Hide the label if MoteLabel = "mote id" [set label who] ;; Show mote id if MoteLabel = "sensed value" [set label s] ;; Show sensed value ] end
The NetLogo procedures for this applet can be downloaded directly as: Protocol4.14.nlogo
All the NetLogo simulation models for this book depend on two library files: gsn.nls and env.nls
These files should be placed in the parent directory of the .nlogo file (and are common to all the .nlogo models on this website).