ABSTRACT

Time synchronization is a critical piece of infrastructure for any distributed system. Distributed, wireless sensor networks make extensive use of synchronized time, but often have unique requirements in the scope, lifetime, and precision of the synchronization achieved, as well as the time and energy required to achieve it. Existing time synchronization methods need to be extended to meet these new needs. We outline the synchronization requirements of future sensor networks and present an implementation of our own low-power synchronization scheme, post-facto synchronization. 

Many PC-based operating systems use tick counting to keep time. Unfortunately, supporting this form of timekeeping accurately in a virtual machine is difficult.

Because the guest operating system keeps time by counting interrupts, time as measured by the guest operating system falls behind real time whenever there is a timer interrupt backlog. 

TABLE OF CONTENT

CHAPTER ONE

CHAPTER TWO

CHAPTER THREE

CHAPTER FOUR

CHAPTER FIVE