Status date

The proposed solution would provide End-users, equipped with a standard UMTS terminal, with a number of interesting services such as: TV channel customised for mobile customer (e.g. to follow local or important sport events), personalised streaming of data (e.g. personalised multimedia newspaper), access to satellite ISP (Internet Service Providers).

At the moment of project start, the technical solution existed only on the paper and no experiments have been done yet, for this reason a preliminary work must be performed in order to have the necessary elements to present the solution to the potentially interested subjects (i.e. Telecom Operators, Satellite Operators and Content Providers).

The project objectives therefore are the following:

1) Providing a detailed Technical Feasibility Analysis
2) Providing a Commercial Feasibility Analysis
3) Carrying on some experiments in order to test eventual practical problems related to the solution proposed.

The solution surely sounds good and seems to allow a very efficient distribution of a particular class of services and contents through UMTS access networks; however such qualitative feeling must be enforced. If the project objectives will be met at the end of the project, the idea which is at the basis of World-Link will be ready to be promoted.

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The eventual success of the World-Link concept is depends essentially on the choice of three subjects: Telecom Operators, Satellite Operators and Content Providers. For this reason the key issues of the project coincides with their main puzzles:

1. Is the technology reliable?
2. What about the costs of the solution?
3. Are the end-users interested to services supported by World-Link concept?

Only if we will be able to move significant steps in the direction of clarifying these fundamental issues, World-Link architecture will be adopted.


The benefits brought by the project should consist in the demonstration that World-Link architecture is very convenient for the delivery of a set of important services to UMTS Customers.
World-Link concept should be preferable to potential existing competitor systems with respect to the provision of those services which require a broadcast / multicast transmission.
The proposed system appears, first of all, convenient from the costs point of view.
Other expected point strength of the World-Link concept are: 

  • fast deployment, 

  • easy interconnection with different Content Providers 

  • flexibility in service planning.

Obviously all these benefits assume a relevant weight only in case that End-user services requiring broadcast / multicast transmission to mobile customers are an important segment of the overall mobile service offer. This is why a binding market analysis will be carried out.


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The integration between UMTS access technology and GeoSat Systems for telecommunications require the insertion, in each base station necessary for UMTS coverage, of a parabolic satellite antenna (pointed towards a pre selected Geo-Sat) and an equipment box able to adapt satellite transmission stream to the suitable UMTS Channel (which uses a terrestrial frequency). The above mentioned box has to be interconnected through the appropriate open UMTS interfaces to the UMTS network, in order to allow the UMTS operator to manage the offered services.

The solution proposed has no impact on the satellites and no specific impact on UMTS standards; it can be seen as an add-on technology which allows exploiting the advantages of Geo-Sat Systems for telecommunications also in the context of 3G mobile services.

Because of the large number of UMTS sites required for coverage (Hundreds of thousands in Europe!) it is important to underline that in case of broadcast/multicast transmission, the satellite mean is very competitive in terms of costs in comparison with equivalent terrestrial alternatives because it illuminates all sites with a single transmission.

Together with the traditional network elements, it is fundamental to consider in the high level architecture at least a Service Centre. It is a server able to support a variety of services based on the distribution of contents to the UMTS customers. Since 3G services won't be merely communication services between two users, such nodes will play a very important role in the delivery of 3G services.

The reported figure illustrates the actual UMTS high level architecture which is thought to be used to deliver a large number of internet-based multi-media services. In addition to the known UMTS architectu


Project Plan is directly related with project objectives, therefore in addition to WP 1000 (Management & Control) there are three other WPs, each of one focused on one of the declared objectives.

WP 2000 (Technical Feasibility Analysis) will cover the first four months.
WP 3000 (Experimental Analysis) will start at the end of the Technical Feasibility Analysis and will finish at the end of the project.
WP 4000 (Commercial Feasibility Analysis) will last all the duration of the project.

Current status

The ESA Project: SME-1-AAS "WORLD-LINK" is now completed. "Technical Feasibility Analysis" has shown that no decisive technical problems have significant impact against the adoption of the "World-Link" option.

The most important technical conclusion, which has emerged, is that standardisation activities too have started to consider some architectures compatible with World-Link. This is a very important and positive element: in fact the support of standards is the best guarantee of technical feasibility. Since 3GPP groups are currently working, standardization trends are constantly monitored and no standardization obstacles seem to be on the way of emerging.

The output of "Technical Feasibility Analysis" has allowed the prosecution to the "Experimental Phase" as planned at the beginning of the project. In particular it has been investigated the impact of the delays and transmission errors (introduced by the satellite link) on the correct working of the interface protocols defined for the connection of the base stations to the network; the experimental activities have given useful elements for the eventual real implementation of the "World-Link" concept.

A public service demonstration using real network apparatus has also been perepared using the Siemens test-plants. The scope of this demonstration is mainly promoting the idea which lies under the "World-Link" concept.

The "Commercial Feasibility Analysis" is also arrived to at an important conclusion: end-user services, which are conveniently supported by World-Link architecture, have been identified, they belong to the so called class of the MBMS (Multicast Broadcast Mobile Services), and a "Cost Analysis" of the possible solutions able to support such services has been completed. It has been shown that the "World-Link" option is cheaper both of any terrestrial CDN option or of any solution based on combination of UMTS network with external DVB/DAB infrastructures.

A "Market Analysis" has been carried too; it has been based on interviews to a number of decision makers representatives of the various subjects which must face the market. The main outcome of such analysis is that all industries involved - or simply interested - in UMTS see the MBMS as an important segment of the whole UMTS offer.