Satellite vs. Cellular: How They Stack Up

It’s difficult to overstate the global impact of cellular technology. The ability to wirelessly transmit both voice and data has fundamentally altered the way we live and work, creating vast opportunities for both business and public benefits. The International Telecommunication Union reports that there are roughly 8 billion active mobile cellular telephone subscriptions worldwide — more than the entire global population.

Yet, there are certain situations in which cellular communication is not feasible due to infrastructure or operational limitations. In these instances, satellite communication becomes a very dependable alternative. Many industries operating in remote areas require a combination of both satellite and cellular to ensure there are no critical gaps in communication capabilities.

In this post, we’ll compare some of the key operational, coverage and cost characteristics of cellular communications and the two main options for satellite communications.

INFRASTRUCTURE

Cellular relies upon terrestrial, or land-based, infrastructure. Transmissions are relayed through a network of fixed-location cell towers that cover a specific geographic area, typically between one mile and 20 miles depending on the terrain. The quality of your signal is often determined by proximity to a tower, which is why calls can be dropped when you move out of range. Roaming enables continuous service when moving between cellular networks.

Meanwhile, satellite services transmit signals via communication satellites orbiting the Earth. Communications satellites have transponders comprising both an integrated receiver and a transmitter. A satellite phone sends radio signals to a satellite, which then relays the signal to a land-based station that then routes the call to the Public Switched Telephone Network (PSTN).

VSAT (very small aperture terminal) and BGAN (broadband global area network) are the two most common satellite communication options. The BGAN network comprises four satellites owned by Inmarsat, while VSAT operates on the networks operated by service providers. VSAT solutions are faster and move more data, but BGAN terminals are more portable and easier to set up.

COVERAGE

The continued spread of cell towers has improved the reliability of cellular communication. There are now roughly 400,000 towers in the U.S., and tower density is expected to increase rapidly now that the FCC has eased restrictions on “small cells” — mini-cell towers that can be installed on light poles and other city infrastructure to expand connectivity options in preparation for 5G services.

However, cellular has significant limitations. In remote locations and on oceans, lakes, rivers and other waterways, tower construction is simply impossible. In addition, natural disasters, extreme weather events, cable cuts and power outages can all put towers out of commission.  During times of heavy cellular usage, such as disasters, data throughput and availability are severely limited.

Because they don’t rely upon towers and other land-based infrastructure, satellite services offer increased reliability for remote applications. Satellite also works better in remote areas and places where dense forests, mountains and even the Earth’s curvature can interfere with cellular signals. Satellite network operators are better able to manage peak usage than cellular service providers, ensuring reliable throughput and connectivity during disasters. However, heavy rain and other harsh weather conditions can affect satellite reception and cause momentary service interruptions.

Of the two primary satellite options, BGAN has the edge in coverage. The four satellites used in the BGAN network are in a geostationary orbit above the equator and synchronized with the rotation of the earth below. This makes them accessible from anywhere on the globe except the north and south poles. VSAT also uses geostationary satellites, but the coverage is not seamless because users need separate contracts on satellites owned by multiple providers.

COSTS

Cellular can be the less expensive option, although charges for usage beyond the subscribed plan can increase cellular costs dramatically. Satellite costs include the costs of deploying satellite receivers and networking gear, and ongoing costs involved with accessing the satellite. Of the two satellite options, BGAN is more expensive than VSAT.

Of course, cost is typically not the primary consideration when evaluating a satellite or cellular solution. In nearly all situations, satellite will provide much higher network availability and security than cellular. In many instances, the best approach may be a combination of VSAT for primary communications with BGAN or cellular as an emergency backup.