Networked and Embedded Systems Laboratory

Tryear

Trmonth

Trnumber

Title

Abstract

Time keeping and synchronization are important services
for networked and embedded systems. High quality timing
information allows embedded network nodes to provide
accurate time-stamping, fast localization, efficient duty cycling
schedules, and other basic but essential functions - all
of which are required for low power operation.
In this paper we present a new type of local clock source
called Crystal Compensated Crystal based Timer (XCXT)
and a number of novel algorithms that effectively utilize it to
achieve low power consumption in wireless sensor networks.
The XCXT has timing accuracies similar to timers based on
temperature compensated crystal oscillators (TCXO) but
has a lower implementation cost and requires less power.
Our initial 8MHz prototype unit, using the simplest algorithm,
achieves an effective frequency stability of ±1.2ppm
and consumes only 1.27mW. On the other hand, commercially
available TCXOs with similar stability can cost over
10 times as much and consume over 20mW.
In addition to the prototype, we will present algorithms
that will improve the XCXT’s power consumption by at least
48%, depending on application and environmental conditions.
We will also show how XCXT’s power efficiency can
be improved even further by employing clocks at different
frequency when different time granularities are required by
an application.

Filename

File

Urlpdfpaper

Urlsrcpaper

Urlpdfpresentation

Urlsrcpresentation

Urlavmedia

Urldoi

Urlpublisher

Urlgooglescholar

Urlciteseer

Pubin

Pubvol

Pubnum

Pubnum end

Pubpagefirst

Pubpagelast

Pubpagecount

Pubdate

Pubdate end

Pubplace

Publisher

Ispublic

Islabdocument

Miscattributes

Document category

Main research area

Editing document