The objectives of “The role of Satellite in converged mobile/fixed/broadcasting environments” are to investigate:
- Seamless video delivery to the end user across different access technologies.
- Maintaining the integrity and wherever applicable, adapting and enriching the quality of the video media across the whole distribution chain.
- Considering advanced encoding technologies such as Scalable Video Coding (VCM), Multi-View Coding (MVC) in the video adaptation and enrichment process.
- Matching these application-level features with the specifics of the integrated network architecture.
Breaking this up into further details, the following general issues are to be treated in the study:
- Definition of integration scenarios and service requirements for satellite and terrestrial LTE networks.
- Investigation of different integrated network architectures with a special focus on video centric solutions.
- Validation of the proposed solutions for a selected number of representative use cases via end-2-end simulations.
- Formulation of recommendations for future work such as the setup of reference test bed implementations for experiments at scale and dissemination of the main results to relevant fora (e.g., standardisation bodies).
The study aims to answer the following two central questions:
- What are the trade-offs between using LTE and satellite network transport technology to supply the end user with multimedia data?
- What is the impact and benefit of using advanced video technologies and video/network adaptation techniques for offering seamless video delivery?
“Scenario definition” is the second phase of WP2000. Based on the topics found useful in Phase 1 of this WP, the relevant integration scenarios (including the associated service offerings) will be specified and analysed (using only a top-level view on the (air) interfaces). This analysis will contain a critical as to what extra benefit is obtained by the satellite in these scenarios (i.e. whether the use of the satellite on top of a terrestrial LTE appears commercially sensible).
Also, in the 4th phase of WP3000, referred to as “Architecture comparison,” different proposed solutions will be compared. This includes discussion of potential gains over existing systems in terms of feasibility and cost-benefit-analysis of deployment, service availability/coverage, resource usage, and additional service offerings. Following this, most promising solution(s) for each approach based on the outcome of the comparison will be identified. These solutions will be then kept as reference architectures for the remainder of the study.
For integration purposes, two major scenarios exist:
S1: Usage of satellite for backhauling in an LTE network:
Scenario S1 can offer an advantage over a terrestrial-only backhaul network, if the connection via other carriers (e.g., directional microwave transmission, cable, fibre) is either more costly or impractical due to other reasons. Especially directional microwave transmission is used very often in cellular networks. Hence, a satellite for backhaul could only be interesting for very remote cells. Another motivation for satellite backhaul are moving (femto-)cells, like LTE eNBs in trains, planes or coaches, which currently do not fit into a conventional terrestrial LTE(-A) infrastructure. Payload from such cells could be backhauled by a satellite much more easily than using a terrestrial connection.
One example of S1
S2: Usage of satellite for direct reception and transmission by the User Equipment:
Here, one of the potentially largest advantages for the integration of the satellite is that it offers additional frequency bands to be used by the mobile users:
- L-band 1452-1492 MHz.
- S-band 2170-2200 MHz for downlink plus 30 MHz for uplink.
- Moreover globally in S-band:
- 2500-2520 MHz (downlink – plus 20 MHz for uplink).
- 2520-2670 MHz (satellite broadcast shared with terrestrial services).
Proposed converged application layer architecture
The architecture definition of a converged application layer assuming hybrid lower layer network interfaces to 3GPP LTE, as well as to DVB satellite systems, such as DVB-S2, -SH or the emerging -NGH is an important and central task of this study. Convergence between satellite and cellular network systems will inherently depend on the ability of a system to control data and media flows over the different access technologies.
As depicted in the figure, the system stack of a converged multimedia delivery system with underlying LTE/SAT access technologies is depicted.
System stack of a converged LTE/SAT system
click for larger image
The project is organized in 5 main Work Packages.
- WP1000 is devoted to project management and quality assurance of the project deliverable.
- WP2000: the integration scenarios for satellite and terrestrial LTE networks that are of relevance for the study will be defined. In parallel, specific service requirements for the integration scenarios will be identified and explained in detail.
- WP3000 deals with the definition and selection of suitable end-2-end architectures.
- WP4000: Individual partners then prepare their contributions to the overall end-2-end simulation platform. These components will be integrated and evaluated.
- WP5000 is devoted to the formulation of explicit recommendations based on the results and analysis done. Concrete dissemination activities at standardization bodies are not part of this project due to the limited time frame.