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Surveillance<br />
While there is a great deal of useful and interesting<br />
information available on the Internet, there is<br />
also a great deal of objectionable content found<br />
there as well. While parents can filter information<br />
or sit down with their youngsters in front of<br />
a stationary computer, mobile youths will often<br />
be unsupervised while using their mobile terminals<br />
putting youngsters at a greater risk to encounter<br />
unacceptable content such as violence,<br />
hate/racism, pornography, etc. One can also add<br />
the possibility of manipulative content such as<br />
marketing, which is directly aimed at youths.<br />
Functions such as content management will be<br />
important aspects to consider, as well as how<br />
much parental surveillance is necessary or<br />
acceptable to more independent and mobile<br />
youths.<br />
Technical Challenges<br />
What we have seen so far in the race towards<br />
UMTS and GPRS is the significance of technology<br />
platform choices, frequency licenses and an<br />
overall high bandwidth hype. Less has been<br />
done in order to create content and services suitable<br />
for the new mobile networks.<br />
Today, services available via SMS (short message<br />
service) include traffic reports, flight/airline<br />
information, news, information, personal reminders<br />
and much more. With the introduction<br />
of GPRS and UMTS, there will be a demand for<br />
more specialised and complex services. Youngster<br />
will take these ideas and the technology a<br />
step forward.<br />
Given the importance of location services, a presentation<br />
of the expected evolution of location<br />
services seen from the telecom operators’ viewpoint<br />
will be presented in this article. For further<br />
details please consult [2] and [3].<br />
Location Services<br />
Location awareness will be an essential technical<br />
building block in the Youngster project. Youngster<br />
will not aim to invest work in developing<br />
these methods, but rather pilot location services<br />
and test interfaces for location services. The definitions<br />
throughout this article are:<br />
• Location services (LCS) can be defined as the<br />
capability to provide the geographical location<br />
of a mobile terminal with a given QoS.<br />
• Location based services: Use of geographical<br />
location provided by LCS to enhance other<br />
services.<br />
During 2000 – 2002 mobile operators will test<br />
mobile-based systems and network-based sys-<br />
Telektronikk 1.2001<br />
tems such as Cell-ID in combination with other<br />
methods like Timing Advance (TA). These are<br />
easy to implement in today’s mobile communication<br />
systems, but offer limited accuracy, ranging<br />
from only 100 to 600 m. Multiple overlaying<br />
from different location estimates, or in the case<br />
of TA, the use of the measurement data before<br />
they are transformed to the TA standard parameter<br />
can help to improve accuracy. The multiple<br />
overlaying from different location estimates can<br />
still fail because too few base stations are accessible,<br />
especially in rural areas. These parameters<br />
are already implemented, offer a simple way to<br />
determine location, and can be used for applications<br />
with a low demand for accuracy. TA is also<br />
specified by ETSI [4] and proposed for assistance<br />
of other LCS (Location Services) methods,<br />
and as a fallback.<br />
The first implemented Mobile based Terminal<br />
location systems will use SIM application toolkit<br />
algorithms for position calculations and SMS for<br />
transmitting its location to others (e.g. communication<br />
with location servers and applications).<br />
The development will move away from SIM<br />
toolkit based systems / SMS and instead towards<br />
systems based on new WAP versions (1.2 and<br />
beyond) and/or GPRS/UMTS.<br />
Further, at the start of 2002 the strategy forecast<br />
for mobile operators will be to implement combined<br />
network-based systems like E-OTD (Enhanced<br />
Observed Time Difference) / GPS systems<br />
(Broadcast of assistance data from GPS).<br />
Combined network-based TOA (UL-ToA,<br />
Uplink Time of Arrival) / GPS assisted systems<br />
are also possible, but may eventually turn out to<br />
be too high an investment for operators.<br />
These network-based systems will:<br />
• Enable accuracy for GPS assisted systems<br />
from 10 – 100 metres;<br />
• Offer an average accuracy of 100 – 200<br />
metres for network-based E-OTD or TOA<br />
systems;<br />
• Require a minimum of three base stations and<br />
certain time synchronization between these<br />
(E-OTD)<br />
- This time synchronization will introduce<br />
other benefits such as the possibility to reduce<br />
interference caused by adjacent sites;<br />
- The requirement of at least three base stations<br />
in sight will cause problems in rural<br />
areas where the ability to reach more than<br />
one base station is lower;<br />
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