The mobile equipment, also known as a terminal, varies widely. Early satellite phone handsets had a size and weight comparable to that of a late 1980s or early 1990s mobile phone, but usually with a large retractable antenna. More recent satellite phones are similar in size to a regular mobile phone while some prototype satellite phones have no distinguishable difference from an ordinary smartphones. Satphones are popular on expeditions into remote areas where terrestrial cellular service is unavailable.
A fixed installation, such as used shipboard, may include large, rugged, rack-mounted electronics, and a steerable microwave antenna on the mast that automatically tracks the overhead satellites. Satellite phones have notoriously poor reception indoors, though it may be possible to get a consistent signal near a window or in the top floor of a building if the roof is sufficiently thin. The phones have connectors for external antennas that are often installed in vehicles and buildings. Some systems also allow for the use of repeaters, much like terrestrial mobile phone systems.
In some countries ruled by oppressive regimes such as Burma and Bangladesh possession of a satellite phone can be illegal as their signals will usually bypass local telecoms systems hindering censorship and wiretapping attempts.
Some satellite phones use satellites in geosynchronous orbit. These systems can maintain near-continuous global coverage with only three or four satellites, reducing the launch costs. However the satellites used for these systems are very heavy (approx. 5000kg) and therefore very expensive to build and launch. The satellites sit at an altitude of about and therefore a noticeable delay is present while making a phone call or using data services. The amount of bandwidth available on these systems is substantially higher than that of LEO systems, all three active systems provide portable satellite internet using laptop-sized terminals with speeds ranging from 60 kbits to 512 kbits.
Another disadvantage of geostationary satellite systems is that in many areas, even where a large amount of open sky is present, the line of sight between the phone and the satellite is broken by obstacles such as steep hills and forest and the user will need to find higher ground before being able to use the phone. This is not the case with Low Earth Orbit (LEO) services - even if the signal is blocked by an obstacle one can wait a few minutes until another satellite passes overhead.
Two such systems, both based in the United States started up in the late 1990s but soon went into bankruptcy after they failed to gain the number of subscribers required to fund the large satellite launch costs. They are now operated by new owners who bought the assets for a fraction of their original cost and are now both planning to launch replacement constellations supporting higher bandwidth. Data speeds for current networks are between 2200 bit/s and 9600 bit/s using a satellite handset.
While it is possible to obtain old handsets for the Thuraya, Iridium, and Globalstar networks for approximately $200, the newest handsets are still quite expensive. The iconic Iridium 9505A, although released in 2001, still sells for well over $1,000 new. Since satellite phones are purpose-built for one particular network and cannot be switched to other networks, the price of handsets varies with the performance of the network. If a satellite phone provider encounters trouble with its network the handset prices will fall, then increase once new satellites are launched. Similarly, handset prices will increase when calling rates are reduced.
Among the most expensive satellite phones are BGAN terminals, often costing several thousand dollars. However these satphones provide Broadband Internet as well as voice communications. Satellite phones are sometimes subsidised by the provider if one signs a post-paid contract but subsidies are usually only a few hundred dollars or less.
Since most satellite phones are built under license or the manufacturing of handsets is contracted out to OEM's, operators have a large influence over the selling price. Satellite networks operate under proprietary closed standards, making it difficult for manufacturers to independently make their own handsets.
Inmarsat satellite phones are issued with codes +870 through +874. In the past these codes have been allocated to different satellites but the codes +871 to +874 are due to be phased out at the end of 2008 leaving Inmarsat users with the same country code regardless of which satellite their terminal is registered with.
Low earth orbit systems including some of the defunct ones have been allocated number ranges in the International Telecommunications Union's Global Mobile Satellite System virtual country code +881. Iridium satellite phones are issued with codes +881 6 and +881 7. Globalstar, although allocated +881 8 and +881 9 use U.S. telephone numbers except for service resellers located in Brazil which use the +881 range.
Smaller regional satellite phone networks are allocated numbers in the +882 code designated for "international networks" which is not used exclusively for satellite phone networks.
Calls from satellite phones to landlines are usually around $.80 to $1.50 per minute unless special offers are used. Such promotions are usually bound to a particular geographic area where traffic is low. Globalstar is currently offering unlimited calling plans until 2010 - something almost unheard of with satellite phones but their current network is highly unreliable and could be out of service sometime in 2008..
All satellite phone networks have pre-paid plans, with vouchers ranging from $10 to $5000.
Also, terrestrial cell antennas and networks can be damaged by natural disasters. Satellite telephony can avoid this problem and be critical in natural disaster communications. Satellite phone networks themselves are prone to congestion as satellites and spot beams cover a very large area with relatively few voice channels.