Contiki-NG
tsch-timeslot-timing.c
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1/*
2 * Copyright (c) 2018, RISE SICS.
3 * All rights reserved.
4 *
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29 * This file is part of the Contiki operating system.
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31 */
32
33/**
34 * \file
35 * IEEE 802.15.4 TSCH timeslot timings
36 * \author
37 * Simon Duquennoy <simon.duquennoy@ri.se>
38 *
39 */
40
41/**
42 * \addtogroup tsch
43 * @{
44*/
45
46#include "contiki.h"
47#include "net/mac/tsch/tsch.h"
48
49/**
50 * \brief TSCH timing attributes and description. All timings are in usec.
51 *
52 * CCAOffset -> time between the beginning of timeslot and start of CCA
53 * CCA -> duration of CCA (CCA is NOT ENABLED by default)
54 * TxOffset -> time between beginning of the timeslot and start of frame TX (end of SFD)
55 * RxOffset -> beginning of the timeslot to when the receiver shall be listening
56 * RxAckDelay -> end of frame to when the transmitter shall listen for ACK
57 * TxAckDelay -> end of frame to the start of ACK tx
58 * RxWait -> time to wait for start of frame (Guard time)
59 * AckWait -> min time to wait for start of an ACK frame
60 * RxTx -> receive-to-transmit switch time (NOT USED)
61 * MaxAck -> TX time to send a max length ACK
62 * MaxTx -> TX time to send the max length frame
63 *
64 * The TSCH timeslot structure is described in the IEEE 802.15.4-2015 standard,
65 * in particular in the Figure 6-30.
66 *
67 * The default timeslot timing in the standard is a guard time of
68 * 2200 us, a Tx offset of 2120 us and a Rx offset of 1120 us.
69 * As a result, the listening device has a guard time not centered
70 * on the expected Tx time. This is to be fixed in the next iteration
71 * of the standard. This can be enabled with:
72 * TxOffset: 2120
73 * RxOffset: 1120
74 * RxWait: 2200
75 *
76 * Instead, we align the Rx guard time on expected Tx time. The Rx
77 * guard time is user-configurable with TSCH_CONF_RX_WAIT.
78 * (TxOffset - (RxWait / 2)) instead
79 */
80
82 1800, /* CCAOffset */
83 128, /* CCA */
84 2120, /* TxOffset */
85 (2120 - (TSCH_CONF_RX_WAIT / 2)), /* RxOffset */
86 800, /* RxAckDelay */
87 1000, /* TxAckDelay */
88 TSCH_CONF_RX_WAIT, /* RxWait */
89 400, /* AckWait */
90 192, /* RxTx */
91 2400, /* MaxAck */
92 4256, /* MaxTx */
93 10000, /* TimeslotLength */
94};
95
96/** @} */
uint16_t tsch_timeslot_timing_usec[tsch_ts_elements_count]
TSCH timeslot timing elements in micro-seconds.
Definition: tsch-types.h:145
const tsch_timeslot_timing_usec tsch_timeslot_timing_us_10000
TSCH timing attributes and description.
Main API declarations for TSCH.