María Freire | Researcher
Last June 15th, Gradiant organized a seminar under the title “The satellite role in the mobile communications arena”. Although information on the event has been made available in previously published news, subjects as interesting for the future of satellite communications as the ones discussed are worthy of being exposed in more detail in this article.
Satellite communications are shaping up as the ideal complement of 4G terrestrial mobile network. This convergence will allow users to enjoy advanced broadband communication services in mobile situations with greater coverage. Currently, up to four possible scenarios are identified, distinguished by two aspects:
• User terminal: terrestrial or dual (terrestrial-satellite).
• Satellite-user interface: direct or indirect link. If indirect, it is a backhaul satellite technology with an intermediate link between satellite and user.
To achieve making quality of service as independent of the user’s location as possible, adopted solutions in the same scenario can differ according to the area: urban, rural or remote.
The first scenario consists of using the LTE + e-MBMS terrestrial mobile network with satellite backhaul. As a second possibility, the mobile operator can decide to extend the LTE terrestrial mobile network using S-MIM and DVB-SH satellite technologies. In this way, a user in a semi-urban area has 4G connectivity (LTE) and reception of video, audio and data (DVB-SH), whereas in a remote area, LTE connectivity is lost and replaced with S-MIM satellite access. The third scenario, similar to the preceding one, only substitutes DVB-SH by e-MBMS. Nevertheless, satellite technology continues being behind e-MBMS, providing the services to the mobile operator so it can offer coverage in inaccessible areas. As last option, a satellite operator can increase its offer by including multimedia content distribution and mobile services using S-LTE (LTE version for satellite) + S-eMBMS.
The success of any of the previous scenarios depends on the achievement of key objectives:
• Convergence with terrestrial mobile networks, integrating into one solution all the services requested by the users, as multimedia content broadcast.
• Creation of a sustainable business.
These scenarios will give support to applications in different markets, from aeronautical, providing internet access in airplanes, to mobile terrestrial, offering TV in mobile devices. Being aware of the important role that these networks will play in the future, Gradiant keeps a close monitoring of the evolution of these technologies, and currently participates as well in different projects directly related to LTE, S-MIM and DVB-SH.