Use of portable radios, mobile phones and EPIRBs

  • Mobile phones
  • Radio systems
  • Ethics of mobile phone and portable radio use
  • EPIRBs

When travelling in remote areas it is sometimes necessary to carry some form of radio for contact with the outside world. Obviously, for those of us who carry a pack on our back this form of communication needs to be light and compact and contain its own power source. With these restrictions in mind, a brief description is given of some of the technologies available, together with their advantages and disadvantages.

Portable radio communication devices

Most of the technologies described here use the Ultra High Frequency (UHF) end of the radio spectrum, and space wave radio propagation. This means that these radio signals rely on line of sight transmission. This is like having a light in total darkness— the light will be able to be seen from a very great distance, as long as nothing gets in the way. If something is in the way, some light may refract off other objects so you may still see some light but it will not be as intense. Therefore, it is important that you use your radio or phone in a position where you have the best chance of radio access to a base station or other user. This may involve climbing to the top of a hill or contouring around a spur.

Some other tips for use include:

  • always keep the antenna vertical
  • speak slowly and clearly
  • electronics and water don’t mix—keep your radio or phone dry, and try to make it watertight
  • carry your radio or phone with the battery disconnected when not in use – this will prevent the battery going flat and also prevent more damage if the unit does get wet, but you may lose information stored in memories, such as phone numbers
  • keep batteries warm in temperatures below about 10° to retain charge and ensure they can release stored charge
  • never trust the safety of yourself or your party solely to a radio or phone.

Mobile phones

Mobile phones for communications in the bush

Mobile phones can often be used for communications in the bush and other remote areas. It is recommended that parties carry at least one mobile phone.

All mobiles are not equal. Do some research to determine which mobile phone will be the best for the places you are likely to use it.

Some points to consider are:

  • Check the rating for good reception (e.g. Telstra's "blue tick")
  • A phone that can take an external antenna (there are a few) can get improved reception
  • Check the rated battery life of the phone - both standby and talk time. A phone battery that only lasts a day is a major limitation
  • Choose a phone with inbuilt GPS and/or location services. These can be used for reporting your location, and in some cases for emergency services to track your phone.
  • A waterproof or splashproof phone is desirable for outdoors use. Some example are a Sonim (GSM) and a Motorola Defy (Next G).
  • Phones with resistive touch screens can be difficult to operate if your fingers get sweaty

Networks and carriers

  • A phone without network coverage is useless. Several network operators service mainly cities and urban areas and have poor or non-existent coverage in remote areas.
  • In general, the Telstra NextG network has the best coverage, although call rates and data charges are often higher than competitors
  • Some operators such as Three (now merged with Vodafone) have roaming agreements with Telstra, however they may not get the full coverage or services offered by Telstra's NextG network.
  • Check the coverage offered by network providers carefully before you select one. Look for coverage maps rather than relying on "% of the population covered" statistics.
  • Satellite phones have the best network coverage, but these are expensive to buy and use. While in theory these phones can be used anywhere, they are dependent on their particular satellite network for coverage. On occasions, some satellite phones do not have access to their network.

Phone usage

  • Keep the phone turned off when its not needed. Mobiles operating outside of network coverage will keep "polling" for a base station and will use more power. You can also put the phone into "flight mode" which turns of the network connection.
  • Store the phone in a waterproof pouch that it can be also be used in, or buy a waterproof phone.
  • Turn off Bluetooth, WiFi and GPS functions if they are not needed - they consume extra power.
  • The GPS in some phones relies on the mobile network to render maps, while some phones have maps stored inside them.
  • Most maps in phones are not ideal for bushwalking as they don't have enough detail.
  • You can often get reception from high ground. If you don't have reception, it is worth walking onto a ridge, or further onto a summit.
  • SMS messages use much less power than talking; if you are running low send information via SMS
  • If you are lost and/or in an emergency situation, call 000 and ask for Police. See for more information.

Smart phone applications

While smart phones such as iPhones and Android-based phones often use more power and are more bulky than conventional mobile phones, can run useful applications. Some applications that may be useful include:

  • Inserty (Android): Insert current GPS coordinates in an SMS
  • My Tracks (Android): Record track logs and upload to Google maps
  • CoordTransform (Android): Convert between Lat Lon to UTM coordinates
  • GPS Tracker (Android): Track the location of the phone (requires network coverage)

In summary

Remember, there is no guarantee that a mobile phone will work, so they should not be relied upon for safety or communications. A mobile phone is no substitute for navigation skills, a map, compass, GPS and Personal Locator Beacon. However, with network coverage they can be a useful addition to your safety gear.


The content of this page comes directly from the excellent Bush Search and Rescue Victoria website and is offered here in keeping with BSAR's Creative Commons Attribution/Share-Alike License

BSAR Disclaimer

Satellite phones

Satellite phones (satphones) can be very useful for emergency communications - when they are able to connect via their satellite network.

The major advantage of a satphone is that you have two-way communications and can convey information about your situation by voice or SMS. Unlike an PLB or Spot device, you can get confirmation that your message has been received. Some satphones also now support email. SMS and email communications can be much cheaper than voice communication.

Disadvantages of a Satphone include:

  • You must acquire a satellite from the phone's network provider for it to function.
  • Calls to the Satphone can be very expensive
  • Calls from the Satphone can also be expensive, although prepaid options now offer no ongoing fees or flagfall or roaming charges or minimum spend and call rates of $1.20+GST to any landline anywhere in the world and half that for an SMS or email text message.
  • Not all makes/models have an "emergency button" to call a programmed emergency number
  • The phone cannot send a distress message (like and EPIRB/PLB can) that is picked up by commercial and search and rescue aircraft
  • May not be usable within a moving vehicle. An external antenna may be available for some models to overcome this.
  • Can be slow to acquire satellites and may not work under a dense tree canopy.


Inmarsat IsatPhone Pro

An example of a satphone availabe in Australia is the Inmarsat IsatPhone Pro:

  • Dimensions: 17 cm x 5.3 cm x 3.8 cm Weight 277.8 g
  • Shock resistance: 2.2 m (7.22') drop test Operating range -20°C to 55°C
  • Talk time: Up to 8 hours Standby time: Up to 100 hours
  • Network: 3 geostationary (GEO) satellites in fixed orbit 32,000 km from Earth on the equator, one above PNG, one above Africa and one just south of Mexico. There is no reception in polar regions.
  • Requires GPS fix and network registration to operate.
  • Bluetooth supported for connection to headsets.
  • Users can view their GPS coordinates (lat, long) and send them via SMS or email.
  • Contacts can be uploaded from and synchronised with a computer using supplied software and MS Outlook.
  • SMS messages can be sent to IsatPhone Pro phones for free from
  • No SOS button (that can be programmed to send SMS to specified contacts)

ISatphone Pros can be obtained in Australia from GMDAS +61 8 9331 0000. A $119 prepaid option with calls valid for two years is available from time to time.

The Australian Government is also currently offering a subsidy for the purchase of a Satphone for eligible users:

    • You must apply for the subsidy before you buy the phone
    • You must specify the dealer you intend to buy the phone from on the form - it is best to source a copy of the form from the dealer.



  • To place an emergency call in Australia (normally 000) from a satphone, the number is +61 2 9002 0900.
  • Use the phone where you have a clear view of the sky, keep it still and point the antenna upwards.
  • Keep the phone turned off when not in use to preserve its battery life.



The content of this page comes directly from the excellent Bush Search and Rescue Victoria website and is offered here in keeping with BSAR's Creative Commons Attribution/Share-Alike License

BSAR Disclaimer

Radio systems

UHF radio
UHF Citizen’s Band (CB) radios are commonly used by farmers and other people in rural areas and will often provide better communication than a mobile phone. While still restricted to line of sight usage, the effective coverage is dramatically increased by the use of a simple repeater network. Repeaters are generally sited in high locations and work by receiving on one channel and transmitting on another. Channels 1–8 are set aside for repeater use; Channel 5 is reserved for emergency use. Handheld units are available.

VHF (Very High Frequency) CB radio
Commonly used by truck drivers and four-wheel drive users, hand-held CB radios are limited by power restraints, antenna size and the lack of a repeater network. It is sometimes possible to skip (or bounce) signals off the ionosphere over very long distances, but this is not reliable especially with a hand-held unit.

VHF trunk radio
These are repeater networks used by emergency services and government departments which can provide very good coverage and access to the telephone network. A trunk radio is quite expensive but may be a viable option for groups who can justify the expense and require a reliable system with good coverage.

Ethics of mobile phone and portable radio use

Issues associated with the ethics of mobile phone and portable radio use in the bush (and nearly everywhere else, it seems) tend to crop up with increasing frequency. The main issues usually stem from the motivation of many outdoors enthusiasts to ‘get away from it all’, and the fact that insensitive use of mobile phones can interfere with the sense of isolation they seek. This, of course, relates to using the phone, not carrying it!

Many school groups require the leader to carry a mobile phone or other functioning communication equipment, and often ban them from the packs of students. This is probably sensible from a weight basis as well as behaviour control concerns. With groups of adults, it can be difficult to prevent inappropriate phone use, but asking the offender privately to use the mobile phone away from the rest of the group will often work wonders. Many leaders who carry phones routinely (or on particular trips) do so discreetly, often only telling one other experienced group member of its presence, and limiting the use to emergency situations only.

Emergency Position Indicating Radio Beacons (EPIRBs)

EPIRBs are emergency radio transmitters which, when triggered, send an automatic signal on frequencies monitored worldwide by aircraft and satellites. In Australia, emergency response to these signals is coordinated by the Rescue Coordination Centre of the Australian Maritime Safety Authority in Canberra, which despatches the most suitable emergency response organisation available. Small hand-held units weighing less than 250 g are now available for around $250, and can also be hired. Undoubtedly, EPIRB use has saved lives, through appropriate emergency response to distress signals. They also have some weaknesses, of which all users should be aware:

  • The signal may not be received from deep valleys or under dense canopies.
  • Triggering an EPIRB sends an emergency signal ‘we are in grave and immediate danger to life’. There is no ‘we are in a spot of bother or may be a bit lost’ message option.
  • Once triggered, the signal cannot be cancelled by the user, although false alarms can be notified to the Maritime Safety Authority on 1800 641 792.
  • EPIRBs transmit only. You cannot seek advice, send a specific message, know that the message has been received or even that the signal was successfully transmitted.
  • Searches triggered by EPIRBs are generally undertaken from the air, so groups should make every effort to be visible to searchers in aircraft.

EPIRBs should be regarded as a last resort, and groups need to make every effort to be self reliant in dealing with any emergencies which may arise.