Radio Data Networks Appointed Official Iridium Satellite Network VAR and VAM

Good News for all those frustrated with trying to get signals from remote locations over the GSM/GPRS networks as now RDN have teamed up with Iridium to offer affordable remote sensing and data delivery from anywhere to anywhere, backed up with a unique custom design and integration service and with full compliance to the European RE-D Directive that came into force earlier this year.

RDN with their unique background in the Utility and Rail Sectors already have developed a number of application Gateways that can forward and deliver a multitude of sensor and alarm data over the Iridium network.

• Analogue 4-20mA Levels

• Digital / Alarm Status Signals

• Rainfall

• Pollution Containment Valve Status

• SDI-12 Pressure and temperature from Boreholes

• AMR Meter Reading

• Pump Status and Alarms

• River & Flood Levels

Managing Director, Brian M Back stated we have looked and worked on various satellite based systems in the past. However, we have found that the traditional geostationary satellite systems such as Intelsat and Inmarsat do not provide universal coverage and cannot operate in the shadow of hills or tall buildings. Further, dish or antenna size can be significant making covert deployment or the mounting of units on street furniture impossible.

The Iridium network with its multiple LEO satellites offers universal coverage and an antenna size of just a few cm. Redundancy within the network due to the recent investment of circa $4bn dollars in new satellites also future proofs the network well into the next decade.

Now for the science:

The Iridium’s constellation consists of 66 cross-linked operational satellites, plus six in-orbit spares. The satellites operate in near-circular low-Earth orbits (LEO) about 780 km (483 miles) above the Earth’s surface. There are 11 satellites in each of six orbital planes and their orbits “crisscross” roughly over the North and South poles. The low-flying satellites travel at approximately 17,000 miles per hour, completing an orbit of the Earth in about 100 minutes. It is a function of latitude/longitude and beam coverage, but it typically takes about ten minutes for a satellite to cross the sky from horizon to horizon. Each satellite can project 48 spot beams on the Earth’s surface. The size of each spot beam is approximately 250 miles in diameter and the satellite’s full 48-beam footprint’s approximately 2,800 miles in diameter.

All spot beams and satellite footprints overlap. The network is considered a meshed constellation of interconnected, cross-linked satellites so that each satellite “talks” with the other nearby satellites in front, behind and in adjacent orbits. Thus, the satellite network – much like a cellular network – hands off voice or data communications automatically from one spot beam to another within the satellite footprint, and from one satellite to the next as they pass overhead.

The call is relayed from satellite to satellite around the constellation without touching ground until it is down-linked at an Iridium gateway and subsequently patched into the public switched telecommunication network (PSTN) or VPN for transmission to its destination. And this all happens in fractions of seconds and is completely seamless to the end user. This architecture is unique to Iridium, and it provides inherent advantages in performance and reliability over other mobile satellite services providers.

RDN Press Office 1st September 2017