• a.

  • i.Figure 2 shows two geocoded terrestrial base stations, B1 and B2, that form part of a wireless network. X, Y and Z represent three mobile devices.

    If the location of the mobile devices is estimated by using the coordinates of the nearest base station, what will the estimated positions of X, Y and Z be?

  • ii.The method of device location considered in Part i above is not particularly accurate and in practice the estimation is done slightly differently.

    Using the material in Subsection 6.3.3, outline briefly how cell tower localisation is usually accomplished in practice. You should write as though for a non-technical audience.

  The maximum word limit for Question 6(a)(ii) is 150 words.

  (9 marks)

• b.Networks have a dual' property. They provide information that allows us to estimate our location. But in doing so we may also reveal information about our location to other parties.

  Consider each of the following scenarios and for each one explain whether it could potentially reveal information about your location to other parties.

  • i.While travelling in open country you estimate your location using the GPS built into your phone.
  • ii.While in an urban setting you switch on your phone's WiFi and it polls the various WiFi routers that it can detect within range.
  • iii.While in a shopping centre you estimate your position using a beacon-based system. In order to know the location of any particular beacon your phone uses the id code broadcast by the beacon to look up the location of the beacon in an online directory.

  The maximum word limit for all of Question 6(b) is 100 words.

  (9 marks)

0 1 2 3 4 5 6 7 8 Figure 2 Geocoded base stations and mobile devices 0 1 2 3 4 5 6 7 8 Figure 2 Geocoded base stations and mobile devices