see also:

• risk management when camping
• letting others know where you are - location tracking
• radio basics
• navigation management for hikers
• getting a weather forecast when camping or off-grid
• global positioning system (GPS) / global navigation satellite systems (GNSS)
• satellites and their radio signals

• this page is all about options on how to call for help or communicate with others when your cellular mobile service is not available
• I have not included satellite phones - these are quite expensive and have their place but possibly now superseded by Starlink tech
• Sending text messages on LoRa mesh radio networks such as “meshtastic” or “reticulum” is a new technology but probably not helpful at this stage unless you are in a group (see bottom of page)
• you could go old school and use torches to signal Morse Code - but not many know this any more
• a whistle and mirror are very useful to signal to potential rescuers who may have trouble finding you in thick bushland

• mobile phone boosters which use a wired connection to a single mobile handset are illegal in Australia (but approved cellular mobile repeaters which communicate with multiple handsets using radiofrequency energy and not wires are permitted)
• thus there are legal mobile phone “repeaters” as per https://www.acma.gov.au/list-exempt-repeaters which includes the below:
• these can increase your call and data quality when in low reception areas (will not work if there is no reception though)
• obviously you need a mobile phone with cellular network subscription to one of the networks
• generally do not access metropolitan 5G as these are not needed in this situation - accesses remote and rural 5G NR Low Band instead - bands include 700L/ 850/ 900/ 1800/ 2100 and 2600 Mhz. 700Mhz band is not supported on the Vodafone Network.
• Cel-Fi R41 ROAM CEL-FI GO 5G 4G Vehicle Car Marine Smart Cellular Mobile Signal Booster
  • works on Telstra, Optus and Vodafone networks - user selects which network
  • 18W power usage via 12V DC, requires ground cabling
  • approved models: Cel-Fi ROAM R41-YB 1/3/5/7/8/26/28L
  • https://www.redfleetsafety.com.au/shop/product/88442/r41-roam-cel-fi-go-5g-4g-vehicle-car-marine-smart-cellular-mobile-signal-booster-telstra-optus-mvno/ $AU785 starter pack with internal server antenna which is the one which communicates with your smartphone - still need to buy the external antenna
  • additional higher power external car antenna options
• Telstra have their own versions but only work with Telstra networks

• NOT useful for emergency communications due to limited coverage
• generally not worth carrying while solo hiking, except for group management purposes
  • the GME XRS location services of GME XRS CB radios allows sending your GPS to your colleague with a GME XRS so if you c=get separated you can more easily find each other without needing mobile services - but you will need each device connected by Bluetooth to a smartphone or similar with their XRS Connect app installed and maps previously downloaded.
• they are popular with truckies and caravanners for highway safety usages, 4WD convoys and for groups of hunters
• great for 4WDers who need short distance comms with spotters to assist in recovery operations or just navigating the best path to drive when the track is difficult
• see radio basics

• you will need a phone capable of doing so eg. iPhone 14 or later or Samsung S25 or later
• you cannot send/receive images or videos
• Apple satellite txts
  • if using an iPhone 14 or later with iOS 18 or later, Apple allows emergency SOS txt messages in various countries including Australia mainly via Globalstar LEO satellites but in July 2025, Apple made a deal with SpaceX so guess that will be coming soon if you have iOS 18.3 or later and are in the US on T-Mobile (will also soon have image/video messages in the near future according to Musk)
    • for SMS, you must initiate the conversation unless the recipient is an emergency contact or part of your Family Sharing group
• Telstra SpaceX txts
  • alternatively, if you are on a Telstra UpFront Plan, you can send/receive satellite text messages via Starlink LEO satellites - the network banner should read Telstra SpaceX if it finds satellites
    • coverage in Australia is line of sight outdoors excluding the Australian Radio Quiet Zone in Western Australia and remote offshore territories and islands of Australia.
    • Not suitable for use in emergencies. Does not support one-way messaging e.g., emergency broadcast messaging.
    • see https://www.telstra.com.au/coverage-networks/mobile-technology/satellite-to-mobile

• much more affordable than a satellite phone, a satellite communicator just sends txt messages - no voice.
• a satellite communicator requires a satellite service subscription although usually you can just get a 1 month subscription relatively cheaply (eg. $AU54 annual fee plus $AU25 for a month on Iridium freedom plan) and this will allow a certain number of free messages with extra messages and premium weather messages (hourly forecasts instead of 6hrly plus more days) charged.
• example:
  • iPhone 14 Emergency Call now has satellite communication functionality
    • has automatic car crash detection and fall detection (if used with Apple watch)
    • can just use the two side buttons held down to initiate a satellite SOS call via GlobalStar satellite network
    • a satellite icon will display if it can access satellite when you do not have cellular access
    • there is a practice demo mode as you do need to aim it at a satellite and there is a graphic display to assist
    • will also send your Apple health record details as well as battery level on phone, GPS location and elevation
    • see https://www.youtube.com/watch?v=ilXq-POO4d0
  • Garmin satellite communicator devices
    • this require a subscription to the Iridium Satellite network which lets you send and receive custom and preset text messages or emails with a delivery confirmation.
    • requires clear view of the sky to function
    • can Bluetooth pair with your smartphone via the Earthmate app to provide a user interface for texting, maps, location sharing etc
    • can do two way messaging to other InReach devices
    • can contact GEOS emergency services to activate rescue and get advice via the SOS feature
    • can update a Garmin mapShare webpage to display to friends and family where you are by optionally sending track points at 10 minutely intervals and they can also request a location data to be sent to them.
    • every inReach device comes with free access to a cloud-powered portal to plan your trips with routes and waypoints, create preset messages and quick texts, sync and manage your device settings, update your firmware, download additional TOPO maps, link your social media accounts, store all your location tracking data
    • turn off Bluetooth and Ant+ to save battery, plus keep it turned off if you don't need to do tracking;
    • having tracking on uses more battery but does mean your family and friends can see where you are and if you do fall off a cliff and can't activate the SOS at least they can see where you were!
      • an alternate method is to send them manual preset messages every so often which will save battery power.
    • eg. Garmin InReach Mini
      • 20 days use in power saving mode (Extended tracking mode)
      • for most people this will be a better buy than the much larger, heavier Explore model
      • see YouTube review and how to set up
    • Garmin InReach Explorer
      • adds preloaded DeLorme® TOPO maps with onscreen GPS routing plus built-in digital compass, barometric altimeter and accelerometer
      • NOT great for navigation using the maps! Need to create navigation routes on website BEFORE hiking and you must put in a series of way points to create straight line routes - no good for winding trails!
      • NOT compatible with other Garmin maps!
      • see review on Youtube
      • NB. SE version is slightly cheaper and yellow but does not come with maps or the built-in digital compass, barometric altimeter and accelerometer
  • ZOLEO Global Satellite Communicator
    • no user interface requires Bluetooth to smartphone
    • basic $AU32/mth plan with Iridium
    • creates a dedicated Australian mobile phone number and email address for messaging

• you will need a satellite phone plus satellite sim card and a plan which tend to be quite expensive subscriptions
• Iridium satellite service
  • The Iridium network is a Low Earth Orbit (LEO) satellite constellation consisting of constantly moving satellites
  • Iridium 9555/9575 phone plans usually start at $AU65/month which includes $15 of calls/sms/data; outgoing calls cost $1.98/min; incoming calls are free; can suspend service at $15/mth; min cost is $50 connect fee + 1 month charge;
  • see https://www.pivotel.com.au/plans-iridium-satellite-phone-plans.html
  • Iridium Go ($1699) WiFi hotspot turns your smartphone into a satellite phone
• Inmarsat satellite service
  • Inmarsat operates Geostationary (GEO) satellite networks which utilise a smaller number of satellites, and each satellite provides satellite coverage to a fixed area of the Earth.
  • IsatPhone 2 plan ($1,599.00 RRP) - cheaper than Iridium and start at $AU43/mth but all calls are charged extra
  • does not have as global a coverage as Iridium as the satellites are mainly near the equator and may not be as effective at high latitudes

• Starlink satellite network
  • coverage in 2022 includes “nearly all of Australia and NZ”, most of USA and Europe, Brazil, Chile and Japan
  • require a clear view of the sky to connect
  • aims for global mobile phone service after 2023.
  • Starlink for Recreational Vehicles
    • vehicle mounted or portable standing satellite dish designed for in-motion use (standard Starlink gear is not made for in-motion use)
    • as at 2022, initial cost $AU450 then $AU174/month and you have the ability to pause and un-pause service at any time and is billed in one-month increments, allowing users to customize their service to their individual travel needs.

• this device has ONE JOB only - to send a continuous radio distress signal if you activate it
• latest batteries lasts around 7 years usually
• they need to be registered with the local radio beacon service
• the main downside is they will not activate if you fall off a cliff !
• in Australia, the GME MT610G Accusat GPS Personal Locator Beacon is highly recommended as it is Australian made, has a Sydney factory replaceable 7 yr life battery - most others you have to buy a new device at end of life! check the battery exp date before you buy one!

• the big disadvantage for hikers is that it is highly unlikely there is another device in range unless you are traveling as a group, especially if you are not near the top of a mountain
• so it probably is more of a interesting concept for private groups rather than useful survival tool as it currently stands in 2025
• of course you could set up devices along your route to transmit further but these will need to be powered and weatherproofed
• advantages of this are the devices are cheap, no subscriptions are needed, and it does not need a mobile phone reception, satellite phone or internet to work and devices generally run on 5V USB power only
• you can buy devices which allow private and public text encrypted messages to be sent over a mesh network of transceivers using radio waves
  • NB. “channels” are virtual chatrooms, and not physical radio frequencies like on some other radio devices.
  • you can potentially connect to more distant people via the internet if a device on the mesh is connected to the internet and if you allow MQTT in your settings
• by default, your GPS location is transmitted to everyone via Channel 0 and GPS could be in-built, or via a connected smartphone - you can stop this being sent or only sent to your private group
• each region usually has a set radio frequency for all users
  • in Australia, ensure your Meshtastic devices are configured to use the 915 MHz band and preferably the same frequency slot (usually slot 20) to ensure they can communicate with each other
  • see https://meshtastic.au/wp/?page_id=47 for getting started info for Australia
  • as of June 2025, there were only 17 devices showing up in Victoria, and all were within 80km of Melbourne - see https://meshmap.net/
• for this to work, you will need to be in signal range of the next device and this depends upon:
  • size of your antenna and the nearest device antennae
  • length of coax cable connecting device to antenna (long cables lose a lot of signal)
  • geography (valleys will generally not work well)
  • weather
• you can connect some meshtastic devices to smartphones via BT or USB and use the smartphone to send/receive messages as well as visually see on a map where the other devices in range are including your contacts - see https://meshtastic.org/docs/software/android/usage/
• see also https://www.youtube.com/@Meshtastic
• another similar tech is reticulum
  • has the added advantage over meshtastic you can send files or images
  • uses software on your smartphone such as SideBand which needs to be “side-load” installed as it is not from a usual app store
  • uses BT enabled devices to connect to LoRa as with meshtastic but firmware flashed with RNode instead of Meshtastic
  • see https://www.youtube.com/watch?v=BsAMeMp1hlg
• another similar tech is Chatterbox:
  • see https://www.youtube.com/watch?v=S7-fSyYMR0Q for example of using multiple LoRa devices including a repeater node when hiking - uses ChatterBox and T-Deck

• this technology has been developed not only for privacy but in the event of war or disasters when the internet and phone services may go down and locals need to communicate
• unfortunately Bluetooth LE (Low Energy) has much lower bandwidth than classic Bluetooth so it cannot send audio, images or video, but it can send txt and devices can act as both master and slave at the same time, which is very peer-to-peer friendly and does not require prior pairing
• Bluetooth LE only works to 300m max line of sight (usually much less) and if a recipient isn’t nearby, the message hops from one local phone (with the app) to another phone (with the app) until it reaches its destination phone (with the app)
• nearly all the latest mobile devices now have Bluetooth LE which can even have bidirectional communications with other nearby Bluetooth LE enabled devices even if devices are turned off apparently - this is how Find My Phone works - it relies on your phone being near another phone which is then connected to the internet
• as with radio mesh networks outlined above, you can now also get Bluetooth LE mesh network apps for your devices without needing a separate radio mesh device as is required for LoRa mesh networks
• no user names are needed, no subscriptions, no log ins are required, messages are not stored or traceable, works in Aeroplane mode as only uses Bluetooth LE (which must be turned on for the app to work)
• Briar app
  • encrypted messages via Bluetooth if internet not available;
  • Android phone app but no plans for an iOS app
• Berty Messenger app
  • encrypted messages via Bluetooth based on their Wesh network tech
  • Android and iOS apps - see https://berty.tech/messenger/ - Android version not currently available due to security issues
• BitChat app
  • announced in July 2025, created by Jack Dorsey, one of the founders of Twitter
  • you need to download the BitChat app onto your device
  • it will then find any other devices on the extended mesh Bluetooth LE network and you can send and receive encrypted text messages although July 2025 version “Private message and channel features have not received external security review and may contain vulnerabilities”
  • if ther are only two devices with the app on, it appears to work up to 40m line of sight from one device to another as long as comms has not dropped out - may need to reboot the apps as initial app seems buggy in that respect ³⁾

• these act like 2-way radios BUT they use cellular networks to send messages - NOT traditional radio
• hence not useful for remote campers without cellular network coverage but they usually have GPS functionality