151 lines
5.3 KiB
C
151 lines
5.3 KiB
C
/**
|
|
* \addtogroup sys
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \defgroup timesynch Implicit network time synchronization
|
|
* @{
|
|
*
|
|
* This crude and simple network time synchronization module
|
|
* synchronizes clocks of all nodes in a network. The time
|
|
* synchronization is implicit in that no explicit time
|
|
* synchronization messages are sent: the module relies on the
|
|
* underlying network device driver to timestamp all radio messages,
|
|
* both outgoing and incoming. The code currently only works on the
|
|
* Tmote Sky platform and the cc2420 driver.
|
|
*
|
|
* Every node has an authority level, which is included in every
|
|
* outgoing packet. If a message is received from a node with higher
|
|
* authority (lower authority number), the node adjusts its clock
|
|
* towards the clock of the sending node.
|
|
*
|
|
* The timesynch module is implemented as a meta-MAC protocol, so that
|
|
* the module is invoked for every incoming packet.
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* Copyright (c) 2007, Swedish Institute of Computer Science.
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Header file for a simple time synchronization mechanism
|
|
* \author
|
|
* Adam Dunkels <adam@sics.se>
|
|
*/
|
|
|
|
#ifndef TIMESYNCH_H_
|
|
#define TIMESYNCH_H_
|
|
|
|
#include "net/mac/mac.h"
|
|
#include "sys/rtimer.h"
|
|
|
|
/**
|
|
* \brief Initialize the timesynch module
|
|
*
|
|
* This function initializes the timesynch module. This
|
|
* function must not be called before rime_init().
|
|
*
|
|
*/
|
|
void timesynch_init(void);
|
|
|
|
/**
|
|
* \brief Get the current time-synchronized time
|
|
* \return The current time-synchronized time
|
|
*
|
|
* This function returns the current time-synchronized
|
|
* time.
|
|
*
|
|
*/
|
|
rtimer_clock_t timesynch_time(void);
|
|
|
|
/**
|
|
* \brief Get the current time-synchronized time, suitable for use with the rtimer module
|
|
* \return The current time-synchronized rtimer time
|
|
*
|
|
* This function returns the (local) rtimer-equivalent
|
|
* time corresponding to the current time-synchronized
|
|
* (global) time. The rtimer-equivalent time is used for
|
|
* setting rtimer timers that are synchronized to other
|
|
* nodes in the network.
|
|
*
|
|
*/
|
|
rtimer_clock_t timesynch_time_to_rtimer(rtimer_clock_t synched_time);
|
|
|
|
/**
|
|
* \brief Get the synchronized equivalent of an rtimer time
|
|
* \return The synchronized equivalent of an rtimer time
|
|
*
|
|
* This function returns the time synchronized equivalent
|
|
* time corresponding to a (local) rtimer time.
|
|
*
|
|
*/
|
|
rtimer_clock_t timesynch_rtimer_to_time(rtimer_clock_t rtimer_time);
|
|
|
|
/**
|
|
* \brief Get the current time-synchronized offset from the rtimer clock, which is used mainly for debugging
|
|
* \return The current time-synchronized offset from the rtimer clock
|
|
*
|
|
* This function returns the current time-synchronized
|
|
* offset from the rtimer arch clock. This is mainly
|
|
* useful for debugging the timesynch module.
|
|
*
|
|
*/
|
|
rtimer_clock_t timesynch_offset(void);
|
|
|
|
/**
|
|
* \brief Get the current authority level of the time-synchronized time
|
|
* \return The current authority level of the time-synchronized time
|
|
*
|
|
* This function returns the current authority level of
|
|
* the time-synchronized time. A node with a lower
|
|
* authority level is defined to have a better notion of
|
|
* time than a node with a higher authority
|
|
* level. Authority level 0 is best and should be used by
|
|
* a sink node that has a connection to an outside,
|
|
* "true", clock source.
|
|
*
|
|
*/
|
|
int timesynch_authority_level(void);
|
|
|
|
/**
|
|
* \brief Set the authority level of the current time
|
|
* \param level The authority level
|
|
*/
|
|
void timesynch_set_authority_level(int level);
|
|
|
|
#endif /* TIMESYNCH_H_ */
|
|
|
|
/** @} */
|
|
/** @} */
|