Cell phones are great for use in many backcountry hiking areas, especially near populated areas (e.g., on the East and West Coasts). Going further back into the wilderness is another matter. Even though cell phones do not work reliably  in most wilderness areas, many hikers take them anyway. I take my cell phone on most trips into the backcountry just in case. To give oneself the best chance of communicating in emergencies using a cell phone, it is important to understand their operation and to learn how to maximize their capabilities. This article is designed to do just that.

Beyond the Basics of Cell Phone Operation

To not overload the carrier’s system, standard cellular phones are purposely designed as short distance communication devices. The standard transmitting power is 0.3 watts, a level that is satisfactory if the unit is a mile or less from a cell tower. Under perfect conditions, a line of sight communication with a cell tower might occur up to 50 miles or more.  However, the transmissions must be two-way. It is common in rural or backcountry areas to receive a strong signal from a cell tower, but not have enough handset power to make a voice connection. Voice communications with a cell tower over long distances can occur under the following conditions: (1) calling from a high point; (2) connecting with a cell tower near a major highway or popular National Park where they are designed to be more sensitive; (3) using a phone with either a more sensitive internal antenna or hooking to an external antenna.

The first two conditions turned out to be in operation in the summer of 2002 when a member of our party needed rescuing from a 6200-foot ridge deep in Washington’s North Cascades. The person had suffered a broken leg and ankle in a freak fall. A member of another party in our vicinity (none in our party were carrying cell phones) was able to connect, after several tries, with a 911 operator about 80 direct line miles away. The cavalry (in the form of a U.S. Navy helicopter from Whidbey Island Naval Air Station) arrived five hours later to winch the injured person aboard for a trip to the emergency room.

 

Additional Cell Phone Features Relevant to Hikers

There are several other notable features of cell phone technology that are important for hikers and backpackers in wilderness areas:
 

  • If unsuccessful in making a connection, try moving to various locations and calling at different times; make sure your body is not blocking the cell phone signals.
  • Text messaging uses less battery power than voice messaging.
  • In fringe coverage areas, emergency text messages will often be received when voice data is not (i.e., voice messaging requires more signal strength), but ironically most 911 emergency call centers are not equipped to receive text messages. (Plans to correct this situation are in the works but it will take a few years to implement them.) 
  • Send emergency text messages to several different people in hopes that some will be received and the proper authorities will be contacted.
  • Before any  text message or voice call is connected, the activated cell phone and nearest cell tower will connect with a digital handshake. Cell towers (even those from different carriers) can share this piece of data. These pieces of electronic data require very little energy to send or receive. Emergency responders can sometimes use these electronic breadcrumbs to locate a cell phone even when no call was ever completed.  This characteristic of cell phones and others are explained in a recent Backpacker.com article by Jason Stevenson: PROF. HIKE: THIS POST MIGHT SAVE YOUR LIFE. 
  • A cell phone can often be located by triangulation (“pinging”) when the phone is able to connect with at least three cell towers (very unlikely in wilderness areas).
  • If the receiving cell tower antenna receives a weak signal, it can automatically boost the power of the transmitting cell phone up to the maximum (but then your phone battery will go dead much faster).
  • If your cell battery is very low, try pressing the keys *3370#. Your cell phone will restart with its reserve power; the instrument should show a 50% increase in battery level.
  • Many cell phones have a GPS locating function that is automatically activated when calling 911. Smart cell phones with navigation technology will often be able to determine the latitude and longitude of the phone.
  • Since different cell phone providers have different coverage areas, it is prudent to carry more than one phone in the party that is activated with different cellular carriers.
  • The emergency number worldwide for Mobile is 112. If you find yourself out of the coverage area of your mobile network and there is an emergency, dial 112 and the mobile will search any existing network
  • Non-activated cell phones are required by law in the United States to connect with emergency 911 services (voice data only). In other words, don’t always recycle that old cell phone especially if it is from a carrier different from your currently activated phone. Keep it charged up and handy for emergency use.


[Acknowledgement: Thanks to Chris, an experienced two-way radio and cellular phone technician, for sharing his knowledge about cell phone operation and researching other issues relevant to this article.]

 Conserving Battery Power

Assuming that a voice data connection can be maintained, conserving battery power in an emergency is an overriding concern. To conserve batteries, consider the following:

  • Before making the call, write down all of the critical information in advance and give all of it to the 911 operator at the first contact.
  • After the initial 911 call make arrangements to turn on your phone only for short periods (e.g., five minutes before each hour).
  • Since it takes more power to transmit, encourage the 911 operator or SAR coordinating agency to call you rather than the reverse.
  • Keep the phone in a warm place to maximize the battery.
  • For smart phones, dim the screen and disable syncs and apps.
  • Since they are light in weight, consider carrying an extra battery for longer trips into the backcountry.



Noise Canceling Headsets

One notable enhancement for cell phone use in the backcountry should be considered: a lightweight headset with a background “noise canceling” feature. This enhancement would be especially useful in windy conditions with a weak signal. The headset will also enable you to hold the phone away from your body, which can block signals. I have tried my own headset in the field under windy conditions and it seems to work quite well. It could make all the difference.

 
Essentials Regarding Cell Use in Wilderness Emergencies

Here are the essentials as I understand current cell phone technology (summarized from the above information):


1.    Always carry at least one cell phone into the backcountry and preferably two or more with different carriers.
2.    Be persistent even if you always see “Failed Connection” messages.
3.    Send 911 emergency text messages to multiple individuals.
4.    Move to different locations at different times when attempting to connect.
5.    Leave your phone off most of the time to conserve battery power and keep it in a warm place.


Alternatives to Cell Phones for Wilderness Emergencies

Here is an in-depth article on this subject: Wilderness Emergency Communication Devices. 

EMERGENCIES

Carrying Cell Phones for Wilderness Emergencies