X2nSat satellite gateways: Location is everything

The captain of a ship far from shore rechecks his coordinates against his planned route to ensure he makes it to port on schedule. A Midwestern hospital communicates with neighboring hospitals via sat-phone after a tornado wipes out local cell towers and landlines. A small diner is still able to process credit cards, despite unexpected maintenance knocking out their internet, keeping them from going into the red for the day. Satellites are vital to maintain a well-connected world and providing communication redundancies. What are less appreciated than these wonders of modern technology are the gateways that allow those satellites to communicate with the ground at all.

A satellite gateway (also referred to as a teleport or hub) is a ground station that transmits data to/from the national fiber network to the fleet of satellites in the sky. It houses the large antennas and equipment that convert the Radio Frequency (RF) signal to an Internet Protocol (IP) signal for terrestrial connectivity. X2nSat, veteran satellite network operator of over 20 years, owns and operates gateways out of Petaluma, California, and Las Cruces, New Mexico.

Gateway locations

Location is of the utmost importance when looking for a satellite gateway. With each generation of gateway design, the location preferences change as the satellite network advances to provide higher speeds to end users; however, certain location traits remain consistent across generations. Petaluma and Las Cruces were specifically selected by experts to excel in function not only with current gateway technology, but with the future in mind.

These are preferences for the current generation of satellites:

Mild temperatures with a very dry climate (minimal rain and no snow).
No obstructions, such as buildings or mountains, blocking any views to satellites.
Sufficient and reliable electrical supply.
Access to national fiber from a variety of Tier-1 providers such as AT&T, Verizon, Level 3, etc.
Large expanse of land for antennas as well as future infrastructure expansion.
Low probability of natural disasters such as floods, fires, tornadoes, tsunamis, hurricanes, typhoons or earthquakes.
Proximity to a good source of technical labor, such as a major university.
Free from civil unrest/war zones.

A common misconception is that gateways need to be located near population and media hubs — in North America this generally means the East Coast. Back when second generation gateways were being built, this was necessary as video content was what was primarily being transmitted. As advances in terrestrial transmission, such as fiber optics, and the needs for satellites have changed, gateways could be built in areas that better suited their technical needs, especially regarding weather and environment. The East Coast experiences high levels of annual precipitation and are prone to natural disasters such as hurricanes, blizzards, and the collateral damage that comes with them. That leaves a question: what is the ideal location for current-gen gateways? The answer is the Southwest.

Environment and weather

The Southwest is home to the most arid climate in the United States making it a prime choice for a gateway array. In addition, it contains large expanses of flat, otherwise uninhabitable land opening up the opportunity to dedicated gateway facilities and the option for future expansion without competition from other industries. An added environmental benefit for Las Cruces is its distance from the Pacific Ocean which further removes it from potential inclement weather.

Signals sent between satellites and gateways are analog meaning they are susceptible to interference caused by rain, snow, or even seemingly minor air conditions such as pressure and humidity. Dry and moderate climates allow for the strongest signal for the largest percentage of time each day. Between the Las Cruces and Petaluma, which are both capable of supporting each other’s workloads and both are located in ideal climates, services always maintain incredibly high levels of reliability.

Past gateway locations: Lessons learned

Gateways are the key infrastructure element on the ground for a satellite network. Without them, satellites are cut off from the world and become expensive pieces of metal floating through space. A typical satellite is designed for 15 to 25 years of service. This means that the operator of a gateway must use a very long time horizon in all decisions regarding the development and maintenance of the gateway.

Below are examples that have surprised or caused problems to gateway operators in the past:

Ownership and control over the land was not secure. Upon completion of a lease, the owner chooses to not renew and instead redevelop the land. Often ownership of the land can change with the new owner having different ideas on how best to make money.
Zoning of the land changes. This can prevent future development that is needed to reach new spacecraft being launched.
Neighboring developments can be built (or trees can grow), obstructing line of sight to the satellites.
Location being so isolated that fiber providers will not upgrade their networks or keep up with regular maintenance.
Insufficient room for expansion. Often gateway operators do not leave adequate growing room for expansion, including new antennas and equipment.

X2nSat studied these occurrences extensively when selecting locations for their gateway array, ensuring they would not make these mistakes which could compromise satellite service to clients.

As far as the eye can see and then some

X2nSat operates on both C-band and Ku-band, and can reach over two-thirds of the earth’s surface from both their Las Cruces and Petaluma gateways.

As shown above, the location of the gateways in Petaluma and Las Cruces are highly effective in reaching a majority of the Earth’s surface and covers some of the most remote places out there. This is again made possible by the arrays’ prime location allowing them to operate at peak efficiency and reliability.

Satellite visibility: Finding the right angle

The X2nSat Las Cruces Satellite Gateway and Network Operations Center has clear visibility to the satellite location arc for both geostationary [JS13] and low earth orbit (LEO) satellites. Unlike most gateways, the Las Cruces facility provides the space and infrastructure needed to develop new satellite networks that can provide customizable solutions for customer requirements.

[JS14] Another added benefit of the Las Cruces and Petaluma locations is the high look angle between the gateways and the satellites. The look angle describes the angle between the satellite, gateway and the Earth’s surface. The look angle increases moving towards the equator, and decreases moving north in the United States. As look angle decreases the amount of atmosphere between the gateway and the satellite increases which has deleterious effects on the signal being transferred.

Geographic Separation: Keeping Eggs in Separate Baskets

Geographic redundancy is important to ensure high availability of business critical systems across multiple locations, mitigating the risk of environmental outages.

Businesses can reduce downtime by replicating applications and data across multiple “geo-diverse” locations. Also termed as “geo-redundancy,” the data that is created or updated in a primary location is asynchronously replicated to a secondary location so that the same data exists and is readily accessible in both locations.

Ideally the gateway locations are geographically separated (California and New Mexico for example), so that should one experience a catastrophic event and cannot be restored, the secondary location can quickly and seamlessly take over the primary role. All traffic is automatically rerouted to the secondary site with minimal service downtime for users.

Due to the distance between the two sites, the risk of a single catastrophic event downing both facilities approaches zero. Natural disasters such as hurricanes and earthquakes decrease in severity exponentially as distance travelled increases on land. [JS15]

At this point it may seem like putting the most distance possible between two facilities may seem prudent, but this is only true up to a certain degree. Greater distances also mean a larger amount of fiber run between facilities. Additionally, parts and professionals cannot easily be moved between stations if they are on opposite sides of the country. All of these factors translate into greater costs. Experts at X2nSat have worked to find the optimized balance between separation for safety and proximity for cost effectiveness to provide the best services at the lowest costs.