which communicate with a personal navigation device pnd such as by short range wireless infrared wireline connection or other connection u2014 regardless of whether satellite signal reception assistance data reception and or position related processing occurs at the device or at the pnd also u201c mobile device u201d is intended to include all devices including wireless communication devices computers laptops etc which are capable of communication with a server such as via the internet wifi or other network and regardless of whether satellite signal reception assistance data reception and or position related processing occurs at the device at a server or at another device associated with the network any operable combination of the above are also considered a u201c mobile device u201d fig1 shows an inertial balance 10 an inertial balance 10 consists of a spring 20 such as a hacksaw blade fixed at one end 22 the other end 24 holds a mass w 30 the inertial balance 10 measures the mass w 30 by measuring the frequency of oscillations the frequency f 40 of oscillation is a function of mass the conversion between frequency and mass may be observed during calibration alternatively hooke 39 s law may be where frequency f is independent of a spring 39 s amplitude of oscillation and.