5G Positioning: Security and Privacy Aspects 295
4) Sending user location information to a remote location without users’ consent: this
situation is also related to the trustworthiness of an LISP, LIC or LBSP; the users
generally agree to certain distribution terms when using location engines and location services, but sometimes the distribution terms are not respected and the user
location is distributed to third parties who were not initially pre‐agreed with the
users. This situation also refers to any inappropriate use of the location information
by LBSP, LISP or LIC [76];
5) Conflictual location policies: depending on the application and service, the location
policy can vary from being user‐defined to provider‐defined or institution‐defined.
In some cases, one or several of these location policies can enter in conflict with each
other [111]. For example, an institutional policy can state that all workers in a certain
building have to be located with a certain precision within the working hours and
such information has to be kept visible only to authorized users, such as the building
management, but the LBSP policy can state that the user himself or herself can either
give permission to the location data to all or to no one. Such situations can usually be
solved if there are common and flexible agreements on the location policies between
different players in the system.
According to the study in [68], while user surveys usually show that users are highly
concerned about their privacy, and in particular their location privacy, the users are
typically not taking active steps to protect their location privacy.
13.7 Passive versus Active Positioning Concepts
The network‐centric and user‐centric localization concepts from the upper plots of
Figure 13.2 are also closely related to the concepts of “passive” and “active” positioning.
The question addressed in this section is about the feasibility of passive positioning
schemes in 5G.
There are two different definitions encountered in the literature of passive versus
active positioning:
1) Definition 1 (adopted here) [63]: Passive positioning schemes refer to the mobile‐
centric positioning schemes when the user device only receives positioning data, but
it does not send full positioning data or data that could reveal the position of the user
in a way that the user identity could be linked to that position. Such schemes can be
used, for example, in conjunction with off‐line downloaded maps to help the user
navigation or user positioning on a map. In contracts, the traditional active positioning schemes in cellular communications rely on the bi‐directional exchange of location data between the network and the mobile terminal. Such active positioning can
take place either in a network‐centric or a mobile‐centric positioning architecture,
but the network is always aware of the user location (with a certain accuracy and
time granularity) in the active schemes. For example, a passive positioning scheme
based on RSS has been recently proposed in [63]. The method, applied for WiFi‐
based positioning, relies on passively listening to WiFi beacon frames in monitor
mode, without disclosing the user device ID (or MAC address). The RSS from several transmitters is collected from those passive beacons and a probabilistic approach,
which relates the RSS to distances, is then employed to compute the user location.
4) Sending user location information to a remote location without users’ consent: this
situation is also related to the trustworthiness of an LISP, LIC or LBSP; the users
generally agree to certain distribution terms when using location engines and location services, but sometimes the distribution terms are not respected and the user
location is distributed to third parties who were not initially pre‐agreed with the
users. This situation also refers to any inappropriate use of the location information
by LBSP, LISP or LIC [76];
5) Conflictual location policies: depending on the application and service, the location
policy can vary from being user‐defined to provider‐defined or institution‐defined.
In some cases, one or several of these location policies can enter in conflict with each
other [111]. For example, an institutional policy can state that all workers in a certain
building have to be located with a certain precision within the working hours and
such information has to be kept visible only to authorized users, such as the building
management, but the LBSP policy can state that the user himself or herself can either
give permission to the location data to all or to no one. Such situations can usually be
solved if there are common and flexible agreements on the location policies between
different players in the system.
According to the study in [68], while user surveys usually show that users are highly
concerned about their privacy, and in particular their location privacy, the users are
typically not taking active steps to protect their location privacy.
13.7 Passive versus Active Positioning Concepts
The network‐centric and user‐centric localization concepts from the upper plots of
Figure 13.2 are also closely related to the concepts of “passive” and “active” positioning.
The question addressed in this section is about the feasibility of passive positioning
schemes in 5G.
There are two different definitions encountered in the literature of passive versus
active positioning:
1) Definition 1 (adopted here) [63]: Passive positioning schemes refer to the mobile‐
centric positioning schemes when the user device only receives positioning data, but
it does not send full positioning data or data that could reveal the position of the user
in a way that the user identity could be linked to that position. Such schemes can be
used, for example, in conjunction with off‐line downloaded maps to help the user
navigation or user positioning on a map. In contracts, the traditional active positioning schemes in cellular communications rely on the bi‐directional exchange of location data between the network and the mobile terminal. Such active positioning can
take place either in a network‐centric or a mobile‐centric positioning architecture,
but the network is always aware of the user location (with a certain accuracy and
time granularity) in the active schemes. For example, a passive positioning scheme
based on RSS has been recently proposed in [63]. The method, applied for WiFi‐
based positioning, relies on passively listening to WiFi beacon frames in monitor
mode, without disclosing the user device ID (or MAC address). The RSS from several transmitters is collected from those passive beacons and a probabilistic approach,
which relates the RSS to distances, is then employed to compute the user location.