Security and privacy of a user of a wireless device may be attacked by a malicious party. One class of attacks is based on a passive attacker listening to timing advance signals transmitted to a device that is executing an attach process. Also, a user of a device may prefer that a mobile network not track the user's geographic position within a cell or base station coverage area.
The Third Generation Partnership Project (3GPP) standards development organization has developed and continues to develop a set of standards referred to as Long Term Evolution (LTE). Some embodiments disclosed herein are illustrated with respect to the 3GPP LTE standards. Further details of LTE standards can be found in i) 3GPP 36.213 v14.2.0, March 2017, “Physical layer procedures,” (hereinafter “3GPP 36.213”), ii) 3GPP 36.211 v14.2.0, March 2017, “Physical channels and modulation,” (hereinafter “3GPP 36.211”), iii) 3GPP 36.321, v14.2.0, March 2017, “Medium Access Control (MAC) protocol specification,” (hereinafter “3GPP 36.321”), iv) 3GPP 36.331, v14.2.0, March 2017, “Radio Resource Control (RRC) Protocol Specification,” (hereinafter “3GPP 36.331”), v) 3GPP 36.133 v14.3.0, March 2017, “Requirements for support of radio resource management,” (hereinafter “3GPP 36.133”), and vi) 3GPP TS 36.300 v11.1.0, March 2012, “Overall Description” (hereinafter “3GPP 36.300”).
In general, a base station tower may be used by an MNO to operate one or more sectors, using directional antennas. A common arrangement is to use antennas with a 120 degree beam pattern and maintain three sectors from a single tower at a given frequency band. From the point of view of the MNO, a cell is a geographic region served by one base station or one sector. The signals observed in that geographic region, from the point of view of a UE, may be referred to as a cell.
A base station in an LTE system is generally referred to as an eNodeB. A UE may also be referred to as a wireless device or device herein.