Abstract: Among other disclosed subject matter, a method includes obtaining, in a mobile device, power information indicating a detected power of respective signals received from multiple transmitters. The method includes determining a location of the mobile device using a formula that uses: locations of the multiple transmitters, a first function of the power information and a second function of respective locations of the multiple transmitters. The method can include recording the determined location.

Abstract: Among other disclosed subject matter, a method includes obtaining, in a mobile device, power information indicating a detected power of respective signals received from multiple transmitters. The method includes determining a location of the mobile device using a formula that uses: locations of the multiple transmitters, a first function of the power information and a second function of respective locations of the multiple transmitters. The method can include recording the determined location.

Abstract: Systems and methods for activating a mobile device for use with a service provider are described. In one exemplary method, a mobile device having a currently inserted SIM card may be prepared for activation using a signing process in which an activation server generates a signed activation ticket encoded with SIM policy data that corresponds to the combination of the device and one of a number of SIM cards belonging to a set of SIM cards defined by the SIM policy data. The activation ticket is securely stored on the mobile device. In another exemplary method the mobile device may be activated in an activation process in which the device verifies an activation ticket against information specific to the device and SIM card in accordance with the SIM policy in the activation ticket, and initiates activation when the verification of the activation ticket is successful.

Abstract: Systems and methods for activating a mobile device for use with a service provider are described. In one exemplary method, a mobile device having a currently inserted SIM card may be prepared for activation using a signing process in which an activation server generates a signed activation ticket encoded with SIM policy data that corresponds to the combination of the device and one of a number of SIM cards belonging to a set of SIM cards defined by the SIM policy data. The activation ticket is securely stored on the mobile device. In another exemplary method the mobile device may be activated in an activation process in which the device verifies an activation ticket against information specific to the device and SIM card in accordance with the SIM policy in the activation ticket, and initiates activation when the verification of the activation ticket is successful.

Abstract: A number of devices co-located at a geographic location can broadcast and receive tokens. Tokens can be exchanged using a communication link having limited communication range. Tokens that are received by a device can be stored locally on the device and/or transmitted to a trusted service operating remotely on a network. In some implementations, the tokens can be stored with corresponding timestamps to assist a trusted service in matching or otherwise correlating the tokens with other tokens provided by other devices. The trusted service can perform an analysis on the tokens and timestamps to identify devices that were co-located at the geographic location at or around a contact time which can be defined by the timestamps. A group can be created based on results of the analysis. Users can be identified as members of the group and invited to join the group.

Abstract: Among other disclosed subject matter, a method includes obtaining, in a mobile device, power information indicating a detected power of respective signals received from multiple transmitters. The method includes determining a location of the mobile device using a formula that uses: locations of the multiple transmitters, a first function of the power information and a second function of respective locations of the multiple transmitters. The method can include recording the determined location.

Abstract: Among other disclosed subject matter, a method includes detecting that a location is to be determined. The method includes selecting at least one among multiple location determination techniques based on a selection criterion. The method includes causing the location to be determined using the selected location determination technique.

Abstract: Systems and methods for activating a mobile device for use with a service provider are described. In one exemplary method, a mobile device having a currently inserted SIM card may be prepared for activation using a signing process in which an activation server generates a signed activation ticket encoded with SIM policy data that corresponds to the combination of the device and one of a number of SIM cards belonging to a set of SIM cards defined by the SIM policy data. The activation ticket is securely stored on the mobile device. In another exemplary method the mobile device may be activated in an activation process in which the device verifies an activation ticket against information specific to the device and SIM card in accordance with the SIM policy in the activation ticket, and initiates activation when the verification of the activation ticket is successful.