Browse Prior Art Database

Method of Determining Timestamp without User Setting the Time

IP.com Disclosure Number: IPCOM000214385D
Publication Date: 2012-Jan-24
Document File: 3 page(s) / 26K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for calculating the correct timestamp for data created on a device by maintaining a simple counter/clock on the device. The device later calculates the correct timestamp relative to a second device (e.g., a computer). The second device, having a more reliable clock mechanism, samples the device's clock/counter system and extrapolates the data to determine and assign each file's correct timestamp for creation.

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Method of Determining Timestamp without User Setting the Time

Mobile devices such as cameras have clocks to associate data (e.g., pictures, videos) with timestamps. These timestamps are often inaccurate because the user fails to correctly set the device's clock. This is especially true for devices that do not connect to the Internet establish the standard time. Correctly setting the clock becomes the user's burden when they first purchase the device or when the device loses power for an extended period of time. The result is inaccurate timestamps associated with data created on the device.

Related prior art includes:


• Tracking time usage on a disconnected client over a period of time [1]


• Interpolated timestamps in high-speed data capture and analysis [2]


• Localizing a remote event timestamp from a network device with an independent clock method and apparatus [3]

Disclosed is a method for calculating the correct timestamp for data created on a device by maintaining a simple counter/clock on the device. The device later calculates the correct timestamp relative to a second device (e.g., a computer). The second device, having a more reliable clock mechanism, samples the device's clock/counter system and extrapolates the data to determine and assign each file's correct timestamp for creation.

The prior art uses more complex techniques to calculate timestamps. For example, both devices must have an established networking protocol to relay timestamps to each other, adding requirements to both devices. This idea relies on simplicity: the mobile device must perform only two functions:


1. Associate each file with a "counter" snapshot

2. Report its current "counter" over some communication protocol, such as a Universal Serial Bus (USB), when requested

Advantages to this system over having the user set the time include:


• Avoids relying on the user to correctly set the time


• The device's clock is relative to itself. It does not need to express time in terms of hours, minutes, seconds, etc.


• Because the device's clock is simple (only requires consistent counter), it can potentially save battery life


• The time is established relative to a remote device (e.g., a computer), which is more likely to have a reliable time

In the preferred embodiment, the device has a simple counter or clock. The only requirement of this clock is that it moves forward in consistent intervals. The counter does not need to be relative to hours, minutes, seconds, etc.

1. When the device creates a data file, it captures a snapshot of the current counter and associates it with the data file


2. The user connects the device to a computer to offload its file contents using e.g.

1


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USB

3. The computer samples the device's current counter twice. In doing so, the computer establishes the device's tick interval relative to its own sense...