CADSAT: Carrier Aggregation in Satellite Communication Networks

Funding source: European Space Agency
Partners: SES S.A., Betzdorf, Luxembourg
Principal investigator: Dr. Symeon Chatzinotas
Duration: 01/2018 - 01/2020

Carrier Aggregation (CA), that is the association of multiple carriers to/from a single user terminal, was introduced in release 11 of 3GPP and is a key enabling technology in terrestrial radio communications networks e.g. Long Term Evolution (LTE) Advanced with CA chipsets already available for the terrestrial market. Given the benefits in the terrestrial wireless environment, the attention for CA grows steadily also for the satellite world.

In fact, as satellite spectrum is a finite resource and user expectations for interactive data services are becoming increasingly demanding, intelligent allocation of resources and the optimum use of transponders is sought. CA could optimise the exploitation of spectrum resources and transponders, simplify multi-band traffic management and lead to a higher peak and average data rates for user terminals (e.g. in hot spots).

CA in the context of satellite can be of high interest in scenarios where a single terminal can satisfy its aggregated leased capacity demand from multiple carriers, occupying spectrum in different transponders. This approach allows leveraging of the underutilised spectrum as it minimizes gaps in the satellite transponders that are not utilized by other services. It can also improve user experience as it leads to a substantial increase in the delivered peak data rate, up to levels not possible when only a single carrier is employed. Furthermore, CA can facilitate interference management through an intelligent allocation of resources in the assignment of multiple carriers to each user.

The benefits of CA could, however, come at the cost of complexity in the satellite terminal (at various levels), the network resource manager and the satellite payload, and inevitably trade-offs are needed. For example, elements of the terminal’s transmit and receive chain (e.g. tuner, SSPA) need to be augmented/replicated, as well as extra processing capabilities are required at the physical and medium access control (MAC) layer. Additionally, re-combining data from multiple carriers (e.g. at GSE level of link-layer) adds to this complexity.

In this context, CADSAT will investigate and elaborate on the benefits and drawbacks of the application of the CA technique through the development of a Software (SW)-based “Carrier Aggregation Demonstrator” (CAD) laboratory testbed. For a set of satellite based applications and operating scenarios, the activity will aim to clarify the interest, if any, of the CA technique and potentially lead the way to its adoption for a plethora of potential satellite use cases.

Project Partners:

• SIGCOM, SnT, University of Luxembourg, Luxembourg,
• SES S.A., Betzdorf, Luxembourg

Funding Details:

• Funding Source: European Space Agency, ARTES AT Program
• Project start date: Jan 2018
• Expected End date: Jan 2020

Management Team:

• PI: Dr Symeon Chatzinotas (SnT)

Research Team:

• Dr Symeon Chatzinotas (SnT) – Project Manager
• Dr Eva Lagunas (SnT) – Technical Contact Point
• Dr Nicola Maturo (SnT)
• Dr Hayder Al-hraishawi (SnT)
• Dr Mirza Kibria (SnT)

Industrial Collaborators:

• Dr. Joel Grotz (SES)
• Dr. Jean Alain Lucciardi (SES)

Relevant Links:

• SeMIGod
• SANSA
• PreDem
• MCPRED
• MEO-MODEM

Contact:

• Dr. Eva Lagunas
• Dr. Symeon Chatzinotas