diff --git a/examples/6tisch/timesync-demo/Makefile b/examples/6tisch/timesync-demo/Makefile new file mode 100644 index 000000000..cd18192d0 --- /dev/null +++ b/examples/6tisch/timesync-demo/Makefile @@ -0,0 +1,24 @@ +CONTIKI_PROJECT = node +all: $(CONTIKI_PROJECT) + +CONTIKI=../../.. + +PLATFORMS_EXCLUDE = sky nrf52dk native + +# force Orchestra from command line +MAKE_WITH_ORCHESTRA ?= 0 +# force Security from command line +MAKE_WITH_SECURITY ?= 0 + +MAKE_MAC = MAKE_MAC_TSCH +MODULES += os/services/shell + +ifeq ($(MAKE_WITH_ORCHESTRA),1) +MODULES += os/services/orchestra +endif + +ifeq ($(MAKE_WITH_SECURITY),1) +CFLAGS += -DWITH_SECURITY=1 +endif + +include $(CONTIKI)/Makefile.include diff --git a/examples/6tisch/timesync-demo/README.md b/examples/6tisch/timesync-demo/README.md new file mode 100644 index 000000000..cf130ee73 --- /dev/null +++ b/examples/6tisch/timesync-demo/README.md @@ -0,0 +1,18 @@ +This is a demonstration of application-level time synchronization using TSCH. + +In a TSCH network, all nodes are synchronized to a global time counter maintained +by the coordinator. This fact can be exploited to measure properties such as latency. + +The modes periodically send their detected network uptime to the coordinator. +The coordinator receives these packets, prints its local network uptime +and the time difference. This time difference is equal to the end-to-end latency, +which includes both the time to prepare the packet, the time until an appropriate +slot in the TSCH schedule, the over-the-air time (negligible). If the packet +does not arrive with the first attempt, it also includes the retransmission time. + +The nodes in this example do not have any notion of the wall-clock time. +That would need additional synchronization between the TSCH network and an external clock source. +For example, one can periodically distribute UNIX timestamps over the UART interface +on the border router to implement this feature. Alternatively, the data collected from +the TSCH network can be timestamped with just TSCH timestamps, and them on the external gateway +these timestamps could be converted to wall-clock time. \ No newline at end of file diff --git a/examples/6tisch/timesync-demo/node.c b/examples/6tisch/timesync-demo/node.c new file mode 100644 index 000000000..408421cec --- /dev/null +++ b/examples/6tisch/timesync-demo/node.c @@ -0,0 +1,139 @@ +/* + * Copyright (c) 2015, SICS Swedish ICT. + * Copyright (c) 2018, University of Bristol - http://www.bristol.ac.uk + * 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. + * + */ +/** + * \file + * A RPL+TSCH node demonstrating application-level time syncrhonization. + * + * \author Atis Elsts + * Simon Duquennoy + */ + +#include "contiki.h" +#include "net/routing/routing.h" +#include "net/netstack.h" +#include "net/ipv6/simple-udp.h" +#include "net/mac/tsch/tsch.h" +#include "lib/random.h" +#include "sys/node-id.h" + +#include "sys/log.h" +#define LOG_MODULE "App" +#define LOG_LEVEL LOG_LEVEL_INFO + +#define UDP_CLIENT_PORT 8765 +#define UDP_SERVER_PORT 5678 + +#define SEND_INTERVAL (60 * CLOCK_SECOND) +/*---------------------------------------------------------------------------*/ +static struct simple_udp_connection client_conn, server_conn; + +PROCESS(node_process, "RPL Node"); +AUTOSTART_PROCESSES(&node_process); +/*---------------------------------------------------------------------------*/ +static void +udp_rx_callback(struct simple_udp_connection *c, + const uip_ipaddr_t *sender_addr, + uint16_t sender_port, + const uip_ipaddr_t *receiver_addr, + uint16_t receiver_port, + const uint8_t *data, + uint16_t datalen) +{ + uint64_t local_time_clock_ticks = tsch_get_network_uptime_ticks(); + uint64_t remote_time_clock_ticks; + + if(datalen >= sizeof(remote_time_clock_ticks)) { + memcpy(&remote_time_clock_ticks, data, sizeof(remote_time_clock_ticks)); + + LOG_INFO("Received from "); + LOG_INFO_6ADDR(sender_addr); + LOG_INFO_(", created at %lu, now %lu, latency %lu clock ticks\n", + (unsigned long)remote_time_clock_ticks, + (unsigned long)local_time_clock_ticks, + (unsigned long)(local_time_clock_ticks - remote_time_clock_ticks)); + } +} +/*---------------------------------------------------------------------------*/ +PROCESS_THREAD(node_process, ev, data) +{ + static struct etimer periodic_timer; + int is_coordinator; + uip_ipaddr_t dest_ipaddr; + + PROCESS_BEGIN(); + + is_coordinator = 0; + +#if CONTIKI_TARGET_COOJA + is_coordinator = (node_id == 1); +#endif + + if(is_coordinator) { + NETSTACK_ROUTING.root_start(); + } + + /* Initialize UDP connections */ + simple_udp_register(&server_conn, UDP_SERVER_PORT, NULL, + UDP_CLIENT_PORT, udp_rx_callback); + simple_udp_register(&client_conn, UDP_CLIENT_PORT, NULL, + UDP_SERVER_PORT, NULL); + + NETSTACK_MAC.on(); + + etimer_set(&periodic_timer, random_rand() % SEND_INTERVAL); + + while(1) { + PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&periodic_timer)); + + if(tsch_is_coordinator) { + break; + } + + if(NETSTACK_ROUTING.node_is_reachable() && NETSTACK_ROUTING.get_root_ipaddr(&dest_ipaddr)) { + /* Send network uptime timestamp to the DAG root */ + uint64_t network_uptime; + network_uptime = tsch_get_network_uptime_ticks(); + simple_udp_sendto(&client_conn, &network_uptime, sizeof(network_uptime), &dest_ipaddr); + LOG_INFO("Sent network uptime timestamp %lu to ", (unsigned long)network_uptime); + LOG_INFO_6ADDR(&dest_ipaddr); + LOG_INFO_("\n"); + } else { + LOG_INFO("Not reachable yet\n"); + } + + /* Add some jitter */ + etimer_set(&periodic_timer, SEND_INTERVAL + - CLOCK_SECOND + (random_rand() % (2 * CLOCK_SECOND))); + } + + PROCESS_END(); +} +/*---------------------------------------------------------------------------*/ diff --git a/examples/6tisch/timesync-demo/project-conf.h b/examples/6tisch/timesync-demo/project-conf.h new file mode 100644 index 000000000..f787b8dfe --- /dev/null +++ b/examples/6tisch/timesync-demo/project-conf.h @@ -0,0 +1,83 @@ +/* + * Copyright (c) 2015, SICS Swedish ICT. + * Copyright (c) 2018, University of Bristol - http://www.bristol.ac.uk + * 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. + * + */ + +/** + * \author Simon Duquennoy + * Atis Elsts + */ + +#ifndef __PROJECT_CONF_H__ +#define __PROJECT_CONF_H__ + +/* Set to enable TSCH security */ +#ifndef WITH_SECURITY +#define WITH_SECURITY 0 +#endif /* WITH_SECURITY */ + +/* USB serial takes space, free more space elsewhere */ +#define SICSLOWPAN_CONF_FRAG 0 +#define UIP_CONF_BUFFER_SIZE 160 + +/*******************************************************/ +/******************* Configure TSCH ********************/ +/*******************************************************/ + +/* IEEE802.15.4 PANID */ +#define IEEE802154_CONF_PANID 0x81a5 + +/* Do not start TSCH at init, wait for NETSTACK_MAC.on() */ +#define TSCH_CONF_AUTOSTART 0 + +/* 6TiSCH minimal schedule length. + * Larger values result in less frequent active slots: reduces capacity and saves energy. */ +#define TSCH_SCHEDULE_CONF_DEFAULT_LENGTH 3 + +#if WITH_SECURITY + +/* Enable security */ +#define LLSEC802154_CONF_ENABLED 1 + +#endif /* WITH_SECURITY */ + +/*******************************************************/ +/************* Other system configuration **************/ +/*******************************************************/ + +/* Logging */ +#define LOG_CONF_LEVEL_RPL LOG_LEVEL_WARN +#define LOG_CONF_LEVEL_TCPIP LOG_LEVEL_WARN +#define LOG_CONF_LEVEL_IPV6 LOG_LEVEL_WARN +#define LOG_CONF_LEVEL_6LOWPAN LOG_LEVEL_WARN +#define LOG_CONF_LEVEL_MAC LOG_LEVEL_WARN +#define LOG_CONF_LEVEL_FRAMER LOG_LEVEL_WARN +#define TSCH_LOG_CONF_PER_SLOT 0 + +#endif /* __PROJECT_CONF_H__ */ diff --git a/os/net/mac/tsch/tsch-slot-operation.c b/os/net/mac/tsch/tsch-slot-operation.c index a801bc92e..4397a4805 100644 --- a/os/net/mac/tsch/tsch-slot-operation.c +++ b/os/net/mac/tsch/tsch-slot-operation.c @@ -52,6 +52,7 @@ #include "net/queuebuf.h" #include "net/mac/framer/framer-802154.h" #include "net/mac/tsch/tsch.h" +#include "sys/critical.h" #include "sys/log.h" /* TSCH debug macros, i.e. to set LEDs or GPIOs on various TSCH @@ -126,9 +127,10 @@ struct tsch_packet *dequeued_array[TSCH_DEQUEUED_ARRAY_SIZE]; struct ringbufindex input_ringbuf; struct input_packet input_array[TSCH_MAX_INCOMING_PACKETS]; +/* Updates and reads of the next two variables must be atomic (i.e. both together) */ /* Last time we received Sync-IE (ACK or data packet from a time source) */ static struct tsch_asn_t last_sync_asn; -clock_time_t last_sync_time; /* Same info, in clock_time_t units */ +clock_time_t tsch_last_sync_time; /* Same info, in clock_time_t units */ /* A global lock for manipulating data structures safely from outside of interrupt */ static volatile int tsch_locked = 0; @@ -347,6 +349,33 @@ get_packet_and_neighbor_for_link(struct tsch_link *link, struct tsch_neighbor ** return p; } /*---------------------------------------------------------------------------*/ +uint64_t +tsch_get_network_uptime_ticks(void) +{ + uint64_t uptime_asn; + uint64_t uptime_ticks; + int_master_status_t status; + + if(!tsch_is_associated) { + /* not associated, network uptime is not known */ + return (uint64_t)-1; + } + + status = critical_enter(); + + uptime_asn = last_sync_asn.ls4b + ((uint64_t)last_sync_asn.ms1b << 32); + /* first calculate the at the uptime at the last sync in rtimer ticks */ + uptime_ticks = uptime_asn * tsch_timing[tsch_ts_timeslot_length]; + /* then convert to clock ticks (assume that CLOCK_SECOND divides RTIMER_ARCH_SECOND) */ + uptime_ticks /= (RTIMER_ARCH_SECOND / CLOCK_SECOND); + /* then add the ticks passed since the last timesync */ + uptime_ticks += (clock_time() - tsch_last_sync_time); + + critical_exit(status); + + return uptime_ticks; +} +/*---------------------------------------------------------------------------*/ /** * This function turns on the radio. Its semantics is dependent on * the value of TSCH_RADIO_ON_DURING_TIMESLOT constant: @@ -623,7 +652,7 @@ PT_THREAD(tsch_tx_slot(struct pt *pt, struct rtimer *t)) tsch_timesync_update(current_neighbor, since_last_timesync, drift_correction); /* Keep track of sync time */ last_sync_asn = tsch_current_asn; - last_sync_time = clock_time(); + tsch_last_sync_time = clock_time(); tsch_schedule_keepalive(); } mac_tx_status = MAC_TX_OK; @@ -882,7 +911,7 @@ PT_THREAD(tsch_rx_slot(struct pt *pt, struct rtimer *t)) int32_t since_last_timesync = TSCH_ASN_DIFF(tsch_current_asn, last_sync_asn); /* Keep track of last sync time */ last_sync_asn = tsch_current_asn; - last_sync_time = clock_time(); + tsch_last_sync_time = clock_time(); /* Save estimated drift */ drift_correction = -estimated_drift; is_drift_correction_used = 1; @@ -1014,6 +1043,13 @@ PT_THREAD(tsch_slot_operation(struct rtimer *t, void *ptr)) /* End of slot operation, schedule next slot or resynchronize */ + if(tsch_is_coordinator) { + /* Update the `last_sync_*` variables to avoid large errors + * in the application-level time synchronization */ + last_sync_asn = tsch_current_asn; + tsch_last_sync_time = clock_time(); + } + /* Do we need to resynchronize? i.e., wait for EB again */ if(!tsch_is_coordinator && (TSCH_ASN_DIFF(tsch_current_asn, last_sync_asn) > (100 * TSCH_CLOCK_TO_SLOTS(TSCH_DESYNC_THRESHOLD / 100, tsch_timing[tsch_ts_timeslot_length])))) { @@ -1115,10 +1151,14 @@ void tsch_slot_operation_sync(rtimer_clock_t next_slot_start, struct tsch_asn_t *next_slot_asn) { + int_master_status_t status; + current_slot_start = next_slot_start; tsch_current_asn = *next_slot_asn; + status = critical_enter(); last_sync_asn = tsch_current_asn; - last_sync_time = clock_time(); + tsch_last_sync_time = clock_time(); + critical_exit(status); current_link = NULL; } /*---------------------------------------------------------------------------*/ diff --git a/os/net/mac/tsch/tsch-slot-operation.h b/os/net/mac/tsch/tsch-slot-operation.h index b1c05697b..22547a2c9 100644 --- a/os/net/mac/tsch/tsch-slot-operation.h +++ b/os/net/mac/tsch/tsch-slot-operation.h @@ -56,7 +56,7 @@ extern struct tsch_packet *dequeued_array[TSCH_DEQUEUED_ARRAY_SIZE]; extern struct ringbufindex input_ringbuf; extern struct input_packet input_array[TSCH_MAX_INCOMING_PACKETS]; /* Last clock_time_t where synchronization happened */ -extern clock_time_t last_sync_time; +extern clock_time_t tsch_last_sync_time; /* Counts the length of the current burst */ extern int tsch_current_burst_count; diff --git a/os/net/mac/tsch/tsch.h b/os/net/mac/tsch/tsch.h index db23b4851..8674ee31a 100644 --- a/os/net/mac/tsch/tsch.h +++ b/os/net/mac/tsch/tsch.h @@ -226,6 +226,12 @@ void tsch_schedule_keepalive(void); * Schedule a keep-alive immediately */ void tsch_schedule_keepalive_immediately(void); +/** + * Get the time, in clock ticks, since the TSCH network was started. + * + * \return The network uptime, or -1 if the node is not part of a TSCH network. + */ +uint64_t tsch_get_network_uptime_ticks(void); /** * Leave the TSCH network we are currently in */ diff --git a/os/services/shell/shell-commands.c b/os/services/shell/shell-commands.c index c8b7d862e..2d0bdfed0 100644 --- a/os/services/shell/shell-commands.c +++ b/os/services/shell/shell-commands.c @@ -584,8 +584,12 @@ PT_THREAD(cmd_tsch_status(struct pt *pt, shell_output_func output, char *args)) } else { SHELL_OUTPUT(output, "none\n"); } - SHELL_OUTPUT(output, "-- Last synchronized: %lu seconds ago\n", (clock_time() - last_sync_time) / CLOCK_SECOND); - SHELL_OUTPUT(output, "-- Drift w.r.t. coordinator: %ld ppm\n", tsch_adaptive_timesync_get_drift_ppm()); + SHELL_OUTPUT(output, "-- Last synchronized: %lu seconds ago\n", + (clock_time() - tsch_last_sync_time) / CLOCK_SECOND); + SHELL_OUTPUT(output, "-- Drift w.r.t. coordinator: %ld ppm\n", + tsch_adaptive_timesync_get_drift_ppm()); + SHELL_OUTPUT(output, "-- Network uptime: %lu seconds\n", + (unsigned long)(tsch_get_network_uptime_ticks() / CLOCK_SECOND)); } PT_END(pt);