Handheld satellite phones are primarily used when one is outside of cellular and landline phone service. Satellite phones are also used in time of emergency when cellular and landline phone service is disrupted or overloaded due to a natural disaster or terrorist act. First Responder Radios work well to communicate within an area of disruption, but are very limited in range and access to landlines outside the disrupted area.
During a natural disaster like hurricanes or tornados, many times the local cellular and landline service is disrupted making the movement of emergency first responders and other resources difficult without reliable communication. Satellite phones are independent of the local phone service so in many cases it is the only reliable communication source available. Communications can be made from a satellite phone to other satellites phones and calls can be made from outside the disrupted area from a landline or cellular phone to a satellite phone. The reverse is also true; a satellite phone can call within the disrupted area to any landline or cellular phone outside the disrupted area. During extreme confusion like a devastating hurricane, many believe a satellite phone could call to a landline or cellular phone within the disrupted area, which cannot be accomplished if the local communication infrastructure is disrupted.
The way a satellite phone is able to communication within an area where all other communication has been disrupted is an outbound voice call is transmitted from the handheld or fixed site satellite phone and goes up to one of the satellites, then down to a ground station outside the disrupted area and the call is transmitted to its destination by landline or cellular network. The reverse is also true; a call from a cellular network and landline network to a satellite phone would be routed to the satellite ground station and switched where it would be transmitted up to a satellite then down to the satellite phone by passing the local disrupted cellular or landline service.
During 911 there were tremendous problems making a call into or out of New York City, not necessarily because the cellular and landline phone systems had been disrupted, but was primarily because of cellular and landline system overload. The local phone system could not handle the massive volume of calls coming into and going out of New York City. Many lessons were learned after 911, one of which was the need for emergency communication by utilizing satellite phones.
The majority of satellite phones first responders prefer are the handle held phones. They are much larger than a modern cellular phone, but still have the portability of a satellite phone. Most handheld satellites phones are the size of an early cellular phone with an extra large antenna. With all handheld satellite phones you must be outside away from large structures, which include buildings and trees. You must have a majority view of the sky to receive good service. Line of site from the satellite phone antenna to a satellite must be obtained. If there is a need for a satellite phone to be used indoors or in a vehicle fixed site satellite phones would provide the solution. Fixed site satellite phones are very simple. They include an external antenna, which gives them line of site to one of the satellites and they normally include a RJ-11 connection that a standard POT phone can be connected to.
In the case of calls from an Iridium satellite phone to Iridium satellite phone the ground stations are not utilized. Calls from an Iridium satellite phone goes to one of the 66 satellites in the Iridium constellation. It is possibly passed to another Iridium satellite through interlinking transmitters, and then transmitted down to the receiving satellite phone, which could be in the same area or on the other side of the earth. Satellite technology bypasses the local cellular and landline service.
In the case of calls from a Globalstar satellite phone to a Globalstar satellite phone the ground stations are utilized. Calls from a Globalstar satellite phone goes up to one of the 48 satellites in the Globalstar constellation. The call is then relayed to one of the Globalstar ground stations where it is then passed back to one of the Globalstar satellites and is then relayed down to the receiving Globalstar satellite phone. This also bypasses the local cellular and landline service.
First responders find it necessary to communicate quickly and with reliability to save lives. Satellite phones in many cases are the only answer.