Geolink is a leading developer of mobile satellite communications systems. More than 70 percent of the earth’s surface is covered by ocean, and is therefore inaccessible to wireline and mobile phone networks. Geolink’s OceanCell GSM Solution uses maritime satellite links to allow mobile phones to be used on cruise ships, military ships, ferries, and other vessels when terrestrial GSM coverage is unavailable.

GSM Coverage

GSM (Global System for Mobile Communications) is a digital cellular phone technology based on TDMA that is the predominant system in Europe, and is also used elsewhere around the world. In fact, more than half of the world’s mobile phone population uses GSM.

Maritime Problem

Geolink had planned to deploy small GSM cells on ferry boats crossing the English Channel. The concept was relatively simple, and most pieces of the solution were readily available. All that was required was to install a small BSC (Base Station Controller) with the associated antennas on the boat, and haul the voice and
signaling traffic over satellite to an operator in Iceland.

But there was a major glitch, the weather conditions in that area would all too often hamper the communication path, and the SS7 (Common Channel Signaling System No. 7) links over the satellite were too unstable to offer reliable service. The business plan was succumbing to the forces of nature.

Maritime Solution

Geolink had the idea of changing the data transport mechanism from circuit to packet by using IP over the same satellite links. The Performance Technologies SEGway device allows GSM communications to occur transparently – even at sea – by transmitting SS7 messages over satellite from any point on earth to a mobile switch. The GSM infrastructure relies on SS7 signaling, so the SEGway devices were critical to the solution.

Small, compact, and operationally transparent, the SEGway 1100 SS7/IP Signaling Platform enables the reliable transport of SS7 messages over low cost, managed IP networks. In the case of Geolink, the SEGway devices are transporting SS7 messages over satellite to enable mobile communications in geographic locations where it would otherwise not be possible.

Licensing Considerations

Geolink’s OceanCell solution is a bit more complex than portrayed previously. It operates in international waters, and therefore is not subject to spectrum licensing. It is, however, a moving tower, and it must not operate within 15 kilometers of land. The solution is equipped with a GPS unit that regularly monitors the ship’s position in relation to the shore, and it automatically turns off the GSM pico-cells before it causes disruption to the wireless networks in the licensed areas. In an effort to minimize operational costs, Geolink is also using simple VoIP media gateways with high compression codes to lower the amount of voice traffic going over satellite.

Current Deployment

Geolink has expanded its customer base to include luxury cruise ships, and the company provides services to eight ships today. The company has plans to expand its customer base even further, and is looking at ways to scale the equipment along with the business.

Despite the initial size and costs, Geolink still managed to obtain a return on investment in less than a year with the Performance Technologies SEGway solution. With the smaller footprint and increased density currently under development, Geolink is positioned for a bright future.