CORDIS Archive
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This area is resplendent with acronyms; these will be decoded as they appear, and assembled at the end of this article in the glossary.
The article also sets the scene for the ACTS Mobile Summit in Granada, Spain on 27-29 November 1996 More information can be found on the WWW at: http://www.sics.se/~onthemove/meetings/grenada.961127.call.html
or email: acts.mobile96@tid.es
UMTS will provide high-quality services using lightweight handsets. Telephony will doubtless be the most popular service, but the UMTS concept extends to providing a full 2 Mbit/sec service on mobile links. With this kind of bandwidth, the system could support video; therefore it will be possible to have a video conference between two mobile terminals.
These figures are impressive. They imply that there will be a marked shift in the telephone "culture" of the 2010s; they also imply that there will be significant economic growth in the areas of service provision and terminal manufacture.
Reassuringly, detailed planning has been carried out to avert the prospect of scarcity in the radio frequency spectrum needed to support the UMTS service.
In the brief existence of the mobile phone in Europe - a little over ten years - there has been occasional network congestion. When a base station becomes congested, no new calls can be made. This is an unsatisfactory state of affairs; users are denied the service they are paying for, and network operators are deprived of revenue. Operators are usually quick to notice potential congestion situations and install a local base station to cope with the demand. (A little known fact is that the pay-back period for a newly-installed and well-positioned base station can be measured in months not years.) These local base stations relieve the pressure on the larger-area base stations; they may be found, say, at an airport or busy train terminus. By introducing more base stations, the radio frequency channels can be re-used further.
UMTS, in common with the first and second generation mobile phone services, has provision for automatically conserving radio frequency spectrum. The problem is that of interference. Since there is only limited bandwidth for the mobile services (50 MHz for GSM), the radio channels within this bandwidth have to be re-used. Even with widely separated base stations, there is a chance of interference when base stations are using the same radio channels.
To reduce the probability of interference, the transmitted power is adjusted, for each call, in proportion to the needs of the system. If a call is made close up to a base station, the latter instructs the mobile terminal to transmit at low power. If, on the other hand, the mobile transmitter is far from the base station, more power will be needed to provide an adequate signal at the base station. (This is why the "talk time" of mobile terminals - the life of the battery - is less in remote areas - the terminal has to transmit at a higher power level in order to reach the base station, and this uses up battery capacity.)
As the user population grows, so the number of base stations must increase in order to avoid congestion. As the number of base stations increases, the average distance to mobile terminals decreases, which means that satisfactory connections can be achieved at lower transmitted power levels. This in turn means that the level of interference owing to frequency re-use is reduced. The system can therefore compensate for growth automatically.
UMTS will operate in the 2 GHz band. It has been allocated a bandwidth of 250 MHz. This is a world-wide allocation, part of the ITU-R recommendations on spectrum planning. Owing to the nature of radio signal propagation at 2 GHz, the size of cells (i.e. the coverage area of a base station) must be smaller than in the lower-frequency systems like GSM. This is not a bad thing, because it will be able to support the ever growing population of mobile phone users. There is an important spin-off. Since the cell size is relatively small, the transmitted power levels will be correspondingly low. This will result in very little interference - in technical terms, the signal-to-noise ratio will be high. These are just the conditions needed for transmitting data at a high data rate, given the restriction on bandwidth. (Engineers will recall Shannon's theorem for maximum data rate through a noisy channel.) Put more succinctly, reducing the cell size enables the data rate to be increased, all things being equal.
A key concept of UMTS is that the bandwidth used by a mobile will be variable. A mobile phone user, twenty years from now, will have a mobile terminal capable of multimedia two-way communications. The data rate for such a terminal will depend upon the particular application being used. In all likelihood, the tariff will take into account the data rate. Broadband services will operate at 2 Mbit/sec, although in wide-area mobile applications this may be reduced to 144 Rbot/sec. (By way of comparison, note that GSM has a data rate of 9.6 Rbot/sec.)
At present, the demand for mobile communications is served by many different networks. There are a variety of applications (paging, telephony, train-based communications, etc.) for each of which there are multiple network operators; look at the transmitter masts on most hills across Europe. Although it gives encouragement to European prosperity that there should be all these services available - in a competitive environment too - it is not, technically, the best solution. Each application will have its own set of networks, and clearly this uses up a lot of precious radio frequency spectrum.
It is foreseen that there will be a convergence between fixed and mobile services. Given that the population of mobile terminals will, at some point in the medium term, exceed that of the PSTN, one must expect a perceptible shift in telephony culture. The idea of having different telephone numbers according to your location or velocity will seem quaint in twenty years time. Furthermore, there will be harmonisation of the interface between users and the mobile system: one point of contact for sales and support, one telephone bill, common operating procedures, etc.
On of the visions of UMTS is that there should be convergence of applications. Not only will this lead to better use of the available spectrum, it will lead to mobile terminals that fulfill multiple functions.
UMTS will provide the functions shown in the diagram that we have provided for you - Warning: it is a big file if you are on a slow link. The diagram is taken from the UMTS Task Force Report. [2] The axes of the diagram are Mobility versus Data rate.
A brief description of the various domains shown in the diagram is given next.
Where the project has its own Web site we have given details.
This project is studying the feasibility and acceptability of advanced security features in existing and future personal communications networks, based on trials and demonstrations. Investigations will be carried out on: the migration of existing mobile security systems to UMTS, fraud detection in UMTS, Trusted Third Parties for end-to-end services in UMTS, the capabilities of future User Identity Modules, and finally the security and integrity of billing in UMTS.
The National Electronics Technology Centre in Ireland maintains a small but useful Web site for COBUCO - see http://www.netc.ie/cobuco.html - including a glossary of terms.
The aim of the CORBUCO project is to build an UMTS system demonstrator capable of both cordless and fixed access, based on ATM (the protocol scheme used on terrestrial broadband networks) and DECT technology (used at present in digital cordless phones). Tests will be carried out to validate the UMTS concepts and to demonstrate the usability of UMTS multimedia/multi-rate services and applications in a business environment. UMTS features will be introduced by exploiting existing DECT and ATM standards, including features such as terminal, network and personal mobility. A series of UMTS cells will be built by extending an existing DECT system. These cells will be linked into one mobile island, and several will be linked into an integrated fixed and mobile network.
In EXODUS, a smooth transition path from second-generation mobile systems (such as GSM) towards UMTS will be developed, focusing on evolution of Core Network capabilities supporting both terminal and personal mobility. EXODUS aims to demonstrate terminal and personal mobility with voice, data and image applications, in both public and private operating environments. The project will also demonstrate IN (Intelligent Network) functionalities to meet UMTS requirements, and enhancements to ATM-based B-ISDN (the broadband version of ISDN) that support mobility management.
This project is demonstrating the feasibility of an intelligent multimode terminal for UMTS, capable of delivering multimedia to mobile users. Sometimes called the "soft terminal", the demonstrator model will make heavy use of digital signal processing technology to make a highly versatile unit.
There are some minimal details of FRAMES on the Web - see
http://www.e-technik.uni-kl.de/FRAMES/ for these.
The overall objective of FRAMES is to define a specification of a UMTS Multiple Access air interface, which will serve as an input towards the UMTS Standardisation process. All backward compatibility aspects to GSM and other digital mobile networks will be taken into consideration. The project will concentrate on the air interface definition to suit different operating environments and Wideband Service needs. The project's system concept will be demonstrated using a pair of base station demonstrators and Mobile Terminals.
Smith System Engineering, the leaders of MOSTRAIN, maintain a colourful and useful Web site, with an area for MOSTRAIN - see http://www.smithsys.co.uk/mostrain/ for details including of deliverables.
MOSTRAIN addresses the need for high-integrity communications services for safety-critical applications in train control. (The need for this is especially clear after several recent train crashes.) It must be ensured that the architecture of new technologies such as UMTS can be configured to deliver mobile communications to and from high speed trains. This includes such aspects as high speed handover and cell geometry (both ground-train and in-train). The characteristics of the high speed railway radio channel must be taken into account in the development of new technologies such as UMTS. One of the objectives is to ensure that new technologies are able to deliver the services required by passengers, public and railway operators, and other transport and professional radio users in general.
Sheffield University maintain an excellent Web site on MultiPort, including latest news, links to standards, and recent conferences - see http://www.shef.ac.uk/uni/projects/multiport/ for details.
Multiport is developing the infrastructure, the software and the systems to demonstrate Portable Digital Assistant (PDA) capability in a single application area, health care. The ultimate objective is to produce a UMTS-capable PDA in the health care area. Intermediate stages will incorporate wireless LAN, GSM trials and UMTS simulations
This project also has a useful and colourful Web site - see http://www.sics.se/~onthemove - with online deliverables and links to other relevant material including other projects in the ACTS Mobile area.
"On The Move" is developing and standardising a mobile Application Programme Interface (API) to facilitate use of multimedia applications. The project is developing an architecture, the Mobile Application Support Environment (MASE) to support both "mobile-aware" and "non mobile-aware" applications. Eventually, the proposed service set will be compatible with the utilisation of an underlying UMTS infrastructure. Mobile API, also being developed by the project, will allow mobile-aware multimedia applications to signal their special "quality of service" requirements (such as bandwidth and transit times) to the computing and communication subsystem below.
This project maintains a Web site - see http://www.cselt.stet.it/sonah/RAINBOW/.
RAINBOW is investigating the architectural and integration issues of the transport and mobility control functions expected for UMTS. This is being carried out using a laboratory implementation based on a conceptual design effort that is part of the Project. The radio access part of UMTS will be implemented in order to study a generic UMTS access infrastructure, able to cope with innovative radio access technique (long term view) and to guarantee a soft migration from second to third generation systems (short term view). All the local transport and control functions tied to the terminal mobility (e.g. handover) will be implemented on a platform emulating the characteristics of the adopted radio access techniques. The infrastructure will be integrated with B-ISDN and realises all the IN (Intelligent Network) based service functions needed to control the upper layer mobility procedures.
This project maintains a small Web site, similar to that for RAINBOW - see http://www.cselt.stet.it/sonah/STORMS/ for details.
This project is considering a software tool for design and planning a UMTS network. The reference environments ranges from indoor coverage (picocells) to regional coverage, such as supplied by satellite systems integrated with the terrestrial cellular structure. The spatial traffic distributions and traffic intensities considered will range from typical office/business to low density areas. The design stage will be constrained by Quality of Service targets, guided by cost optimisation criteria of: Network Elements, interconnection network(s), the data base allocation, the signalling traffic. It is also considering the positioning of current mobile networks in the UMTS perspective.
This project has a Web site at http://www.era.co.uk/div80/bc82/smartant/smartant.htm
The "TSUNAMI II" project will demonstrate that it is feasible and cost-effective to deploy adaptive antennas within the infrastructure of third generation mobile systems such as UMTS. The adaptive antenna will automatically form focused beams towards individual mobile terminals in the cell service area. This will allow frequency re-use within cells, by employing the technique of SDMA (Space Division Multiple Access). It is predicted that the spectral usage efficiency will be improved by a factor of 2 to 3 times.
This has a Web site - see http://www.fen.bris.ac.uk/elec/UMPTIDUMPTI/umptidumpti.html - the site uses "frames" so that you need to use Netscape 2.0 - or equivalent - to access it.
The UMPTIDUMPTI project is developing proposals for meeting user requirements for applications and services, usability requirements, non-conventional uses supporting social integration. It is also specifying interfaces, in particular common application programming interfaces, to system services. Furthermore, it is demonstrating the applications and services in a networked environment, eventually evolving towards a UMTS-type network, using emerging technology and equipment, adapted where necessary.
1st generation system
This term refers to the analogue mobile phone networks: TACS (UK), NMT (Scandinavia), and AMPS (US).
2nd generation system
This term refers to the digital mobile phone networks: GSM, DCS1800, PCS.
3rd generation system
The next generation of mobile communications, typified by UMTS.
CT2
Cordless Telephone system - 2. A 2nd generation cordless telephony system, used in domestic and office environments.
DECT
Digital Enhanced Cordless Telephony. The latest generation of cordless telephony, using digital transmission. The successor to CT2.
FPLMTS
Future Public Land Mobile Telecommunications Systems - see IMT-2000.
IMT-2000
International Mobile Telecommunications - 2000. The New name for the FPLMTS system, promulgated by the ITU.
ITU-R
International Telecommunications Union - Radiocommunication Sector. An agency of the United Nations that deals with regulatory matters, standardisation and spectrum allocations on a global scale.
PMR
Private Mobile Radio. This class of service is used by utilities, ambulances, police, taxis, etc. It is characterised by the way it makes maximum use of limited spectrum. It also has limited functionality (e.g. only calls between mobile to base station). Emerging systems such as TETRA offer much higher functionality PMR, with features such as access to the PSTN, priority channels and calls between mobiles and user groups.
TGMS
Third Generation Mobile Systems. Generic name for mobile telecommunication systems. UMTS is an example of a TGMS; UMTS refers to research and standardisation that is being carried out in Europe.
UMTS
Universal Mobile Telecommunications System. Research and standardisation activity taking place in Europe for the next generation of mobile communications.
WLL
Wireless in the Local Loop. This system is as an alternative to laying copper wires between the local exchange and the subscriber's location. It is being installed in several European countries. In many situations it is a much cheaper solution to providing telephone access than laying new copper cables.
By Adrian Rawlings, Euronet Associates Ltd, 01.11.1996