Ericsson s mobile location solution
We live in a changing world. Landscapes and skylines shift as cities expand and new buildings are erected. People are also changing: over time we tend to dress differently, modify our habits, find new interests, and refine our views on music, politics, and so on. On the face of it, everything is in a state of change. Moreover, the pace at which change occurs seems to be picking up. Under the surface, however, many fundamental constants remain, oblivious to external change the changing world of fashion preys on human vanity (a constant); and the recent shift from wired to wireless or mobile communication is indicative of mankind s as yet unfulfilled need to communicate (another constant).
In other words, although our physical environment or our outward expression and behavior fluctuate, our innermost needs which are the drivers of change do not. This is why Homer s The Iliad and The Odyssey, Shakespeare s Hamlet, and Strindberg s Miss Julie remain timeless and poignant: these works speak to our innermost (and oftentimes hidden) needs. They relate to values, such as love, respect, comfort, and so forth. No matter how much we seem to have changed, it can be argued that our basic needs do not. How fortunate we are to live in an age when technology is maturing to the point that it can offer services that fulfill these basic needs. The mobile location solution is just the sort of breakthrough that addresses needs through personal, customized services.
In this article, the author describes some of the driving forces behind mobile location solutions and introduces the main service categories and their target groups. He then gives an overview of Ericsson s technical solution, which allows operators to achieve immediate and 100% market penetration.
Mobile location solution (MLS) is Ericsson s name for a location system, including applications, that determines the geographic position of mobile subscribers and provides them with relational information and services (Figure 1).
In the early days of telecommunications, we called to a specific location in the hope that the party with whom we wanted to speak would come to the phone. With mobile telephony, however, we know to whom we are calling, but not necessarily his or her whereabouts. Other recent developments, such as the growth and development of information technology and databases (that is, the Internet and associated portals), have introduced completely new prerequisites for the use of information technology. Looking ahead, by combining positional mechanisms with location-specific information, we can offer truly customized personal communication services through the mobile phone or other mobile devices.
In the USA, legal aspects have acted as the driving force behind GSM positioning standardization. The main player in this market has been the Federal Communications Commission (FCC). Organizations that represent fire brigades, hospitals and other emergency centers have also participated in formulating the FCC requirements. Authorities and industry have agreed on the pace and standards for positioning systems that will serve the market. The requirements have not been completely finalized, but an outline and characteristics have been specified: the FCC regulations differentiate between terminal-based (handset-based) and network-based solutions. A terminal-based positioning solution (Box B) relates to positioning intelligence that is stored in the terminal or its SIM card. These kinds of positional mechanism require a new terminal, a new SIM card, or both. In practice, this means that once the system has been installed, subscribers will have to replace their handsets or SIM cards to benefit from it. Market penetration will increase gradually as handsets and SIM cards are replaced over a period of, say, four to five years. Examples of terminal-based solutions are the network-assisted global positioning system (A-GPS), SIM toolkit, and enhanced observed time difference (E-OTD).
By contrast, network-based positioning solutions (Box C) do not require positioning intelligence to be built into the handset (mobile terminal), which means that market penetration is 100% from the day the system or service is launched. Examples of network-based solutions include the cell global identity and timing advance (CGI+TA) and uplink time of arrival (UL-TOA) methods. Because terminal- and network-based positioning systems have different characteristics, the FCC has stipulated separate requirements for each. Today, the only methods that satisfy these requirements are the UL-TOA solution, which is representative of a network-based system, and the A-GPS solution, which is representative of a terminal-based system.
Outside the USA, the development of positioning systems is mainly driven by commercial considerations. These considerations, however, are every bit as strong as the legal aspects that drive the development in the USA. There are three main commercial reasons why operators would invest in positioning services:
Reduced costs operators who introduce positioning systems can optimize their networks to trace unsuccessful calls. With this information, they can adapt their networks (without waste or overdimensioning) to match calling patterns.
Increased revenues the potential of commercial services that use positioning information is truly infinite. What is more, professional and private subscribers are willing to pay for these services.