Prior art

The prior art for US patent 9736618, "Techniques for sharing relative position between mobile devices," includes numerous patent documents that generally pertain to location-based services and tracking. The priority date of US9736618 is April 4, 2005. Therefore, any patent document filed before this date is considered prior art under 35 U.S.C. § 102 (AIA).

A review of the patent citations listed on Google Patents for US9736618 reveals a significant number of prior art references, particularly in the domain of wireless tracking systems, location-based group services, and emergency notification systems for mobile devices. Many of these citations are related, often being continuations or divisionals from the same original applications.

The most relevant prior art references, based on their titles and early filing dates, are detailed below, along with an analysis of which claims of US9736618 they potentially anticipate.

Most Relevant Prior Art References

US20020102980A1: User location system for mobile radio network
- Full Citation: US20020102980A1, "User location system for mobile radio network," invented by Bahl et al., published August 1, 2002.
- Publication/Filing Date: Filed August 1, 2001; Published August 1, 2002.
- Brief Description: This patent application describes a system for determining the location of mobile units within a mobile radio network, primarily using base station signal information. The location data is processed by a location server and can be delivered to various location-aware applications, which may then push information back to the mobile unit.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 1: This reference describes a system where a mobile device couples to a server via a wireless network (a mobile radio network), collects position data (derived from base station signals), and the server processes this data for use by applications. While it emphasizes a single mobile unit's location for an application rather than mutual two-way sharing between two specific user devices, the core elements of server-mediated location determination and delivery are present. The '618 patent's unique aspect of mutual exchange between two user devices might differentiate it from this prior art, which focuses on providing a mobile unit's location to an application.
US20040063445A1: Location-based group services
- Full Citation: US20040063445A1, "Location-based group services," invented by Smith et al., published April 1, 2004.
- Publication/Filing Date: Filed October 2, 2002; Published April 1, 2004.
- Brief Description: This patent application details a system and method for providing location-based services to members of a group. It involves creating user profiles with group memberships, receiving location information for these members, and delivering location-based services or alerts based on their location and group affiliation. This includes displaying other group members' locations.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 1: This reference directly anticipates the fundamental concept of Claim 1. It describes a system where members of a group (analogous to "first wireless device" and "second wireless device") have their locations collected and delivered, effectively facilitating the exchange of position data among them via a server. The '618 patent explicitly refers to "Buddy Lists" and "groups" for location sharing, which is a direct overlap. [cite: The provided patent text states "the process of the invention only allows exchanging and mapping of position data with persons on a Buddy ListTM programmed into a Buddy WatchTM (synonym for Buddy TrackerTM) device", and also refers to "adding groups and members".]
  - Claim 18: This prior art introduces "location-based group services," which implies managing groups and potentially defining roles. However, the abstract of US20040063445A1 does not explicitly disclose a hierarchical arrangement where a "supervisor" cannot be removed from a group by "employees" and requires a specific passcode for such an action, as specified in Claim 18. This specific level of access control and unremovable supervisor function in the '618 patent would likely distinguish it. [cite: The provided patent text states "Only the supervisor or parent will have the necessary password to remove himself from a Buddy List or watch list."].
  - Claim 20: While this reference deals with group services, its abstract does not describe location sharing functionality being specifically configured to be active only during defined working hours (e.g., Monday to Friday), which is a key limitation of Claim 20.
US20040180678A1: Location based system with zone alert
- Full Citation: US20040180678A1, "Location based system with zone alert," invented by Lin et al., published September 16, 2004.
- Publication/Filing Date: Filed March 12, 2003; Published September 16, 2004.
- Brief Description: This patent application describes a location-based system designed to monitor the geographical position of a mobile device and trigger alerts when the device enters or leaves predefined zones. These "zone alerts" can automatically send notifications to designated recipients, serving purposes such as parental monitoring.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 1: This reference broadly covers the steps of a mobile device collecting position data and a system/server processing it for notifications. It doesn't explicitly detail mutual, two-way location sharing between two user devices, but it does show a system for collecting and acting on location data. The '618 patent discusses "position alert data" which can trigger an alarm if a child's position deviates from a specified location, directly aligning with the "zone alert" concept. [cite: The provided patent text states "position alert data can be configured to send an alarm signal to a parent if a child's position gets too close to a specified location or too far from the home location or some other location."].
  - Claim 10: While US20040180678A1 addresses location-based alerts for monitoring, it does not explicitly disclose the specific "personal bread crumbs" mode of Claim 10. Claim 10 involves a server sending an "Are you OK?" message, initiating a timer, and if no timely response is received, automatically sending distress messages. This specific interactive and unresponsive-trigger mechanism is not apparent in the abstract of this prior art.
US20050181829A1: System and method for using wireless device for enabling and sharing of position tracking of other wireless devices
- Full Citation: US20050181829A1, "System and method for using wireless device for enabling and sharing of position tracking of other wireless devices," invented by Du et al., published August 18, 2005.
- Publication/Filing Date: Filed February 13, 2004; Published August 18, 2005.
- Brief Description: This patent application describes a system and method where a wireless device user can enable and share their position tracking information with other authorized wireless devices, and simultaneously view the positions of those other authorized wireless devices. It emphasizes user control and secure exchange of location information.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 1: This reference appears to directly anticipate Claim 1 of US9736618. Its description of "enabling and sharing of position tracking of other wireless devices" and the ability to "view the position of other authorized wireless devices" directly maps to the mutual exchange of position data between a first and second wireless device via a server, as defined in Claim 1.
US20050215264A1: Method and system for location tracking, notification, and emergency services for mobile devices
- Full Citation: US20050215264A1, "Method and system for location tracking, notification, and emergency services for mobile devices," invented by Du et al., published September 29, 2005.
- Publication/Filing Date: Filed March 24, 2004; Published September 29, 2005.
- Brief Description: This patent application describes a comprehensive system offering location tracking, event-based notifications, and emergency services for mobile devices. It can track device locations, send notifications for events (e.g., emergency button activation), and provide location data to emergency responders.
- Potential Anticipation (35 U.S.C. § 102):
  - Claim 1: Given its broad scope of "location tracking, notification, and emergency services for mobile devices," and shared inventorship with US20050181829A1 (which explicitly describes mutual sharing), this patent likely anticipates the general method of Claim 1 where devices exchange location data through a server.
  - Claim 10: This reference's focus on "emergency services" and "notification" suggests a strong overlap with the intent of Claim 10. However, Claim 10 is very specific about the "personal bread crumbs" mode, where an "Are you OK?" message is sent, a timer monitors for a response, and lack of a timely response triggers automated distress messages. While this prior art would cover sending location to emergency services upon an event (like a button press), it is not clear from the abstract if it includes the particular sequence of an inquiry, an ignored inquiry (timeout), and subsequent distress messages, which are distinctive features of Claim 10. A detailed review of the full patent text would be necessary to ascertain if these specific elements are present.

Most Relevant Prior Art References

Other Cited Prior Art Documents (Filed before April 4, 2005)