LoRaPHY.h

00001 /**
00002  *  @file LoRaPHY.h
00003  *
00004  *  @brief An abstract class providing radio object to children and
00005  *         provide base for implementing LoRa PHY layer
00006  *
00007  *  \code
00008  *   ______                              _
00009  *  / _____)             _              | |
00010  * ( (____  _____ ____ _| |_ _____  ____| |__
00011  *  \____ \| ___ |    (_   _) ___ |/ ___)  _ \
00012  *  _____) ) ____| | | || |_| ____( (___| | | |
00013  * (______/|_____)_|_|_| \__)_____)\____)_| |_|
00014  *   (C)2013 Semtech
00015  *  ___ _____ _   ___ _  _____ ___  ___  ___ ___
00016  * / __|_   _/_\ / __| |/ / __/ _ \| _ \/ __| __|
00017  * \__ \ | |/ _ \ (__| ' <| _| (_) |   / (__| _|
00018  * |___/ |_/_/ \_\___|_|\_\_| \___/|_|_\\___|___|
00019  * embedded.connectivity.solutions===============
00020  *
00021  * \endcode
00022  *
00023  * Description: LoRa PHY layer
00024  *
00025  * License: Revised BSD License, see LICENSE.TXT file include in the project
00026  *
00027  * Maintainer: Miguel Luis ( Semtech ), Gregory Cristian ( Semtech ) and Daniel Jaeckle ( STACKFORCE )
00028  *
00029  * Copyright (c) 2017, Arm Limited and affiliates.
00030  * SPDX-License-Identifier: BSD-3-Clause
00031  *
00032  */
00033 
00034 #ifndef MBED_OS_LORAPHY_BASE_
00035 #define MBED_OS_LORAPHY_BASE_
00036 
00037 #include "lorawan/LoRaRadio.h"
00038 #include "lorawan/system/LoRaWANTimer.h"
00039 #include "lorawan/lorastack/phy/lora_phy_ds.h"
00040 #include "platform/NonCopyable.h"
00041 
00042 class LoRaPHY : private mbed::NonCopyable<LoRaPHY> {
00043 
00044 public:
00045     virtual ~LoRaPHY();
00046 
00047     /** Stores a reference to Radio object.
00048      *
00049      * Application is responsible for constructing a 'LoRaRadio' object
00050      * which is passed down to the PHY layer.
00051      *
00052      * @param radio    a reference to radio driver object
00053      */
00054     void set_radio_instance(LoRaRadio& radio);
00055 
00056     /** Puts radio in sleep mode.
00057      *
00058      * Requests the radio driver to enter sleep mode.
00059      */
00060     void put_radio_to_sleep(void);
00061 
00062     /** Puts radio in standby mode.
00063      *
00064      * Requests the radio driver to enter standby mode.
00065      */
00066     void put_radio_to_standby(void);
00067 
00068     /** Puts radio in receive mode.
00069      *
00070      * Requests the radio driver to enter receive mode for a given time or to
00071      * enter continuous reception mode.
00072      *
00073      * @param is_rx_continuous    if true, sets the radio to enter continuous
00074      *                            reception mode.
00075      *
00076      * @param max_rx_window       duration of receive window
00077      */
00078     void setup_rx_window(bool is_rx_continuous, uint32_t max_rx_window);
00079 
00080     /** Delegates MAC layer request to transmit packet.
00081      *
00082      * @param buf    a pointer to the data which needs to be transmitted
00083      *
00084      * @param size   size of the data in bytes
00085      */
00086     void handle_send(uint8_t *buf, uint8_t size);
00087 
00088     /** Enables/Disables public network mode.
00089      *
00090      * Public and private LoRaWAN network constitute different preambles and
00091      * Net IDs. This API isused to tell the radio which network mode is in use.
00092      *
00093      * @param set    true or false
00094      */
00095     void setup_public_network_mode(bool set);
00096 
00097     /** Provides a random number from radio.
00098      *
00099      * Returns a 32-bit random unsigned integer value based upon RSSI
00100      * measurements.
00101      *
00102      * @return    a 32-bit long random number
00103      *
00104      */
00105     uint32_t get_radio_rng();
00106 
00107     /**
00108      * @brief calculate_backoff Calculates and applies duty cycle back-off time.
00109      *                          Explicitly updates the band time-off.
00110      *
00111      * @param joined                Set to true, if the node has already joined a network, otherwise false.
00112      * @param last_tx_was_join_req  Set to true, if the last uplink was a join request.
00113      * @param dc_enabled            Set to true, if the duty cycle is enabled, otherwise false.
00114      * @param channel               The current channel index.
00115      * @param elapsed_time          Elapsed time since the start of the node.
00116      * @param tx_toa                Time-on-air of the last transmission.
00117      */
00118     void calculate_backoff(bool joined, bool last_tx_was_join_req, bool dc_enabled, uint8_t channel,
00119                            lorawan_time_t elapsed_time, lorawan_time_t tx_toa);
00120 
00121     /**
00122       * Tests if a channel is on or off in the channel mask
00123       */
00124     bool mask_bit_test(const uint16_t *mask, unsigned bit);
00125 
00126     /**
00127       * Tests if a channel is on or off in the channel mask
00128       */
00129     void mask_bit_set(uint16_t *mask, unsigned bit);
00130 
00131     /**
00132       * Tests if a channel is on or off in the channel mask
00133       */
00134     void mask_bit_clear(uint16_t *mask, unsigned bit);
00135 
00136     /** Entertain a new channel request MAC command.
00137      *
00138      * MAC command subsystem processes the new channel request coming form
00139      * the network server and then MAC layer asks the PHY layer to entertain
00140      * the request.
00141      *
00142      * @param channel_id The channel ID.
00143      * @param new_channel A pointer to the new channel's parameters.
00144      *
00145      * @return bit mask, according to the LoRaWAN spec 1.0.2.
00146      */
00147     virtual uint8_t request_new_channel(int8_t channel_id, channel_params_t * new_channel);
00148 
00149     /** Process PHY layer state after a successful transmission.
00150      * @brief set_last_tx_done Updates times of the last transmission for the particular channel and
00151      *                         band upon which last transmission took place.
00152      * @param channel The channel in use.
00153      * @param joined Boolean telling if node has joined the network.
00154      * @param last_tx_done_time The last TX done time.
00155      */
00156     virtual void set_last_tx_done(uint8_t channel, bool joined, lorawan_time_t last_tx_done_time);
00157 
00158     /** Enables default channels only.
00159      *
00160      * Falls back to a channel mask where only default channels are enabled, all
00161      * other channels are disabled.
00162      */
00163     virtual void restore_default_channels();
00164 
00165     /** Processes the incoming CF-list.
00166      *
00167      * Handles the payload containing CF-list and enables channels defined
00168      * therein.
00169      *
00170      * @param payload Payload to process.
00171      * @param size Size of the payload.
00172      *
00173      */
00174     virtual void apply_cf_list(const uint8_t* payload, uint8_t size);
00175 
00176     /** Calculates the next datarate to set, when ADR is on or off.
00177      *
00178      * @param restore_channel_mask    A boolean set restore channel mask in case
00179      *                                of failure.
00180      *
00181      * @param dr_out                  The calculated datarate for the next TX.
00182      *
00183      * @param tx_power_out            The TX power for the next TX.
00184      *
00185      * @param adr_ack_counter         The calculated ADR acknowledgement counter.
00186      *
00187      * @return True, if an ADR request should be performed.
00188      */
00189     bool get_next_ADR(bool restore_channel_mask, int8_t& dr_out,
00190                       int8_t& tx_power_out, uint32_t& adr_ack_counter);
00191 
00192     /** Configure radio reception.
00193      *
00194      * @param [in] config    A pointer to the RX configuration.
00195      *
00196      * @param [out] datarate The datarate index set.
00197      *
00198      * @return True, if the configuration was applied successfully.
00199      */
00200     virtual bool rx_config(rx_config_params_t * config, int8_t* datarate);
00201 
00202     /** Computing Receive Windows
00203      *
00204      * For more details please consult the following document, chapter 3.1.2.
00205      * http://www.semtech.com/images/datasheet/SX1272_settings_for_LoRaWAN_v2.0.pdf
00206      * or
00207      * http://www.semtech.com/images/datasheet/SX1276_settings_for_LoRaWAN_v2.0.pdf
00208      *
00209      *                 Downlink start: T = Tx + 1s (+/- 20 us)
00210      *                            |
00211      *             TRxEarly       |        TRxLate
00212      *                |           |           |
00213      *                |           |           +---+---+---+---+---+---+---+---+
00214      *                |           |           |       Latest Rx window        |
00215      *                |           |           +---+---+---+---+---+---+---+---+
00216      *                |           |           |
00217      *                +---+---+---+---+---+---+---+---+
00218      *                |       Earliest Rx window      |
00219      *                +---+---+---+---+---+---+---+---+
00220      *                            |
00221      *                            +---+---+---+---+---+---+---+---+
00222      *Downlink preamble 8 symbols |   |   |   |   |   |   |   |   |
00223      *                            +---+---+---+---+---+---+---+---+
00224      *
00225      *                     Worst case Rx window timings
00226      *
00227      * TRxLate  = DEFAULT_MIN_RX_SYMBOLS * tSymbol - RADIO_WAKEUP_TIME
00228      * TRxEarly = 8 - DEFAULT_MIN_RX_SYMBOLS * tSymbol - RxWindowTimeout - RADIO_WAKEUP_TIME
00229      *
00230      * TRxLate - TRxEarly = 2 * DEFAULT_SYSTEM_MAX_RX_ERROR
00231      *
00232      * RxOffset = ( TRxLate + TRxEarly ) / 2
00233      *
00234      * RxWindowTimeout = ( 2 * DEFAULT_MIN_RX_SYMBOLS - 8 ) * tSymbol + 2 * DEFAULT_SYSTEM_MAX_RX_ERROR
00235      * RxOffset = 4 * tSymbol - RxWindowTimeout / 2 - RADIO_WAKE_UP_TIME
00236      *
00237      * The minimum value of RxWindowTimeout must be 5 symbols which implies that the system always tolerates at least an error of 1.5 * tSymbol.
00238      */
00239     /*!
00240      * Computes the RX window timeout and offset.
00241      *
00242      * @param [in] datarate         The RX window datarate index to be used.
00243      *
00244      * @param [in] min_rx_symbols   The minimum number of symbols required to
00245      *                              detect an RX frame.
00246      *
00247      * @param [in] rx_error         The maximum timing error of the receiver
00248      *                              in milliseconds. The receiver will turn on
00249      *                              in a [-rxError : +rxError] ms interval around
00250      *                              RxOffset.
00251      *
00252      * @param [out] rx_conf_params  Pointer to the structure that needs to be
00253      *                              filled with receive window parameters.
00254      *
00255      */
00256     virtual void compute_rx_win_params(int8_t datarate, uint8_t min_rx_symbols,
00257                                        uint32_t rx_error,
00258                                        rx_config_params_t  *rx_conf_params);
00259 
00260     /** Configure radio transmission.
00261      *
00262      * @param [in]  tx_config    Structure containing tx parameters.
00263      *
00264      * @param [out] tx_power     The TX power which will be set.
00265      *
00266      * @param [out] tx_toa       The time-on-air of the frame.
00267      *
00268      * @return True, if the configuration was applied successfully.
00269      */
00270     virtual bool tx_config(tx_config_params_t* tx_config, int8_t* tx_power,
00271                            lorawan_time_t* tx_toa);
00272 
00273     /** Processes a Link ADR Request.
00274      *
00275      * @param [in]  params          A pointer ADR request parameters.
00276      *
00277      * @param [out] dr_out          The datarate applied.
00278      *
00279      * @param [out] tx_power_out    The TX power applied.
00280      *
00281      * @param [out] nb_rep_out      The number of repetitions to apply.
00282      *
00283      * @param [out] nb_bytes_parsed The number of bytes parsed.
00284      *
00285      * @return The status of the operation, according to the LoRaMAC specification.
00286      */
00287     virtual uint8_t link_ADR_request(adr_req_params_t* params,
00288                                      int8_t* dr_out, int8_t* tx_power_out,
00289                                      uint8_t* nb_rep_out,
00290                                      uint8_t* nb_bytes_parsed);
00291 
00292     /** Accept or rejects RxParamSetupReq MAC command
00293      *
00294      * The function processes a RX parameter setup request in response to
00295      * server MAC command for RX setup.
00296      *
00297      * @param [in] params    A pointer to rx parameter setup request.
00298      *
00299      * @return The status of the operation, according to the LoRaWAN specification.
00300      */
00301     virtual uint8_t accept_rx_param_setup_req(rx_param_setup_req_t* params);
00302 
00303     /**
00304      * @brief accept_tx_param_setup_req Makes decision whether to accept or reject TxParamSetupReq MAC command.
00305      *
00306      * @param ul_dwell_time The uplink dwell time.
00307      * @param dl_dwell_time The downlink dwell time.
00308      *
00309      * @return True to let the MAC know that the request is
00310      *         accepted and MAC can apply TX parameters received
00311      *         form Network Server. Otherwise false is returned.
00312      */
00313     virtual bool accept_tx_param_setup_req(uint8_t ul_dwell_time, uint8_t dl_dwell_time);
00314 
00315     /** Processes a DlChannelReq MAC command.
00316      *
00317      * @param channel_id The channel ID to add the frequency.
00318      * @param rx1_frequency The alternative frequency for the Rx1 window.
00319      *
00320      * @return The status of the operation, according to the LoRaWAN specification.
00321      */
00322     virtual uint8_t dl_channel_request(uint8_t channel_id, uint32_t rx1_frequency);
00323 
00324     /** Alternates the datarate of the channel for the join request.
00325      *
00326      * @param nb_trials    Number of trials to be made on one given data rate.
00327      *
00328      * @return             The datarate to apply .
00329      */
00330     virtual int8_t get_alternate_DR(uint8_t nb_trials);
00331 
00332     /** Searches and sets the next available channel.
00333      *
00334      * If there are multiple channels found available, one of them is selected
00335      * randomly.
00336      *
00337      * @param [in]  nextChanParams Parameters for the next channel.
00338      *
00339      * @param [out] channel The next channel to use for TX.
00340      *
00341      * @param [out] time The time to wait for the next transmission according to the duty cycle.
00342      *
00343      * @param [out] aggregatedTimeOff Updates the aggregated time off.
00344      *
00345      * @return Function status [1: OK, 0: Unable to find a channel on the current datarate].
00346      */
00347     virtual lorawan_status_t set_next_channel(channel_selection_params_t* nextChanParams,
00348                                               uint8_t* channel, lorawan_time_t* time,
00349                                               lorawan_time_t* aggregatedTimeOff);
00350 
00351     /** Adds a channel to the channel list.
00352      *
00353      * Verifies the channel parameters and if everything is found legitimate,
00354      * adds that particular channel to the channel list and updates the channel
00355      * mask.
00356      *
00357      * @param [in] new_channel A pointer to the parameters for the new channel.
00358      * @param [in] id          Channel ID
00359      *
00360      * @return LORAWAN_STATUS_OK if everything goes fine, negative error code
00361      *         otherwise.
00362      */
00363     virtual lorawan_status_t add_channel(channel_params_t * new_channel, uint8_t id);
00364 
00365     /** Removes a channel from the channel list.
00366      *
00367      * @param [in] channel_id Index of the channel to be removed
00368      *
00369      * @return True, if the channel was removed successfully.
00370      */
00371     virtual bool remove_channel(uint8_t channel_id);
00372 
00373     /** Puts the radio into continuous wave mode.
00374      *
00375      * @param [in] continuous_wave   A pointer to the function parameters.
00376      *
00377      * @param [in] frequency         Frequency to transmit at
00378      */
00379     virtual void set_tx_cont_mode(cw_mode_params_t * continuous_wave,
00380                                   uint32_t frequency = 0);
00381 
00382     /** Computes new data rate according to the given offset
00383      *
00384      * @param [in] dr The current datarate.
00385      *
00386      * @param [in] dr_offset The offset to be applied.
00387      *
00388      * @return     The computed datarate.
00389      */
00390     virtual uint8_t apply_DR_offset(int8_t dr, int8_t dr_offset);
00391 
00392     /**
00393      * @brief reset_to_default_values resets some parameters to default values
00394      * @param params Pointer to MAC protocol parameters which will be reset
00395      * @param init If true, most of the values will be modified
00396      */
00397     void reset_to_default_values(loramac_protocol_params *params, bool init = false);
00398 
00399 public:
00400     /**
00401      * @brief get_next_lower_tx_datarate Gets the next lower datarate
00402      * @param datarate Current TX datarate
00403      * @return Lower datarate than given one or minimum if lower cannot be found anymore
00404      */
00405     int8_t get_next_lower_tx_datarate(int8_t datarate);
00406 
00407     /**
00408      * @brief get_minimum_rx_datarate Gets the minimum RX datarate supported by a device
00409      * @return Minimum RX datarate
00410      */
00411     uint8_t get_minimum_rx_datarate();
00412 
00413     /**
00414      * @brief get_minimum_tx_datarate Gets the minimum TX datarate supported by a device
00415      * @return Minimum TX datarate
00416      */
00417     uint8_t get_minimum_tx_datarate();
00418 
00419     /**
00420      * @brief get_default_tx_datarate Gets the default TX datarate
00421      * @return default TX datarate
00422      */
00423     uint8_t get_default_tx_datarate();
00424 
00425     /**
00426      * @brief get_default_tx_power Gets the default TX power
00427      * @return Default TX power
00428      */
00429     uint8_t get_default_tx_power();
00430 
00431     /**
00432      * @brief get_max_payload Gets maximum amount in bytes which device can send
00433      * @param datarate A datarate to use
00434      * @param use_repeater If true repeater table is used, otherwise payloads table is used
00435      * @return Maximum number of bytes for payload
00436      */
00437     uint8_t get_max_payload(uint8_t datarate, bool use_repeater = false);
00438 
00439     /**
00440      * @brief get_maximum_frame_counter_gap Gets maximum frame counter gap
00441      * @return Maximum frame counter gap
00442      */
00443     uint16_t get_maximum_frame_counter_gap();
00444 
00445     /**
00446      * @brief get_ack_timeout Gets timeout value for ACK to be received
00447      * @return ACK timeout
00448      */
00449     uint32_t get_ack_timeout();
00450 
00451     /**
00452      * @brief get_default_rx2_frequency Gets default RX2 frequency
00453      * @return RX2 frequency
00454      */
00455     uint32_t get_default_rx2_frequency();
00456 
00457     /**
00458      * @brief get_default_rx2_datarate Gets default RX2 datarate
00459      * @return RX2 datarate
00460      */
00461     uint8_t get_default_rx2_datarate();
00462 
00463     /**
00464      * @brief get_channel_mask Gets the channel mask
00465      * @param get_default If true the default mask is returned, otherwise the current mask is returned
00466      * @return A channel mask
00467      */
00468     uint16_t* get_channel_mask(bool get_default = false);
00469 
00470     /**
00471      * @brief get_max_nb_channels Gets maximum number of channels supported
00472      * @return Number of channels
00473      */
00474     uint8_t get_max_nb_channels();
00475 
00476     /**
00477      * @brief get_phy_channels Gets PHY channels
00478      * @return PHY channels
00479      */
00480     channel_params_t * get_phy_channels();
00481 
00482     /**
00483      * @brief is_custom_channel_plan_supported Checks if custom channel plan is supported
00484      * @return True if custom channel plan is supported, false otherwise
00485      */
00486     bool is_custom_channel_plan_supported();
00487 
00488 public: //Verifiers
00489 
00490     /**
00491      * @brief verify_rx_datarate Verifies that given RX datarate is valid
00492      * @param datarate Datarate to check
00493      * @return true if given datarate is valid, false otherwise
00494      */
00495     bool verify_rx_datarate(uint8_t datarate);
00496 
00497     /**
00498      * @brief verify_tx_datarate Verifies that given TX datarate is valid
00499      * @param datarate Datarate to check
00500      * @param use_default If true validation is done against default value
00501      * @return true if given datarate is valid, false otherwise
00502      */
00503     bool verify_tx_datarate(uint8_t datarate, bool use_default = false);
00504 
00505     /**
00506      * @brief verify_tx_power Verifies that given TX power is valid
00507      * @param tx_power Power to check
00508      * @return True if valid, false otherwise
00509      */
00510     bool verify_tx_power(uint8_t tx_power);
00511 
00512     /**
00513      * @brief verify_duty_cycle Verifies that given cycle is valid
00514      * @param cycle Cycle to check
00515      * @return True if valid, false otherwise
00516      */
00517     bool verify_duty_cycle(bool cycle);
00518 
00519     /**
00520      * @brief verify_nb_join_trials Verifies that given number of trials is valid
00521      * @param nb_join_trials Number to check
00522      * @return True if valid, false otherwise
00523      */
00524     bool verify_nb_join_trials(uint8_t nb_join_trials);
00525 
00526 protected:
00527     LoRaPHY(LoRaWANTimeHandler &lora_time);
00528 
00529     /**
00530      * Verifies the given frequency.
00531      */
00532     virtual bool verify_frequency(uint32_t freq);
00533 
00534 
00535     /**
00536      * Verifies, if a value is in a given range.
00537      */
00538     uint8_t val_in_range(int8_t value, int8_t min, int8_t max);
00539 
00540     /**
00541      * Verifies, if a datarate is available on an active channel.
00542      */
00543     bool verify_channel_DR(uint8_t nbChannels, uint16_t* channelsMask, int8_t dr,
00544                            int8_t minDr, int8_t maxDr, channel_params_t * channels);
00545 
00546     /**
00547      * Disables a channel in a given channels mask.
00548      */
00549     bool disable_channel(uint16_t* channel_mask, uint8_t id, uint8_t max_channels);
00550 
00551     /**
00552      * Counts number of bits on in a given mask
00553      */
00554     uint8_t count_bits(uint16_t mask, uint8_t nb_bits);
00555 
00556     /**
00557      * Counts the number of active channels in a given channels mask.
00558      */
00559     uint8_t num_active_channels(uint16_t* channel_mask, uint8_t start_idx,
00560                                 uint8_t stop_idx);
00561 
00562     /**
00563      * Copy channel masks.
00564      */
00565     void copy_channel_mask(uint16_t* dest_mask, uint16_t* src_mask, uint8_t len);
00566 
00567     /**
00568      * Updates the time-offs of the bands.
00569      */
00570     lorawan_time_t update_band_timeoff(bool joined, bool dutyCycle, band_t * bands,
00571                                        uint8_t nb_bands);
00572 
00573     /**
00574      * Parses the parameter of an LinkAdrRequest.
00575      */
00576     uint8_t parse_link_ADR_req(uint8_t* payload, link_adr_params_t* adr_params);
00577 
00578     /**
00579      * Verifies and updates the datarate, the TX power and the number of repetitions
00580      * of a LinkAdrRequest.
00581      */
00582     uint8_t verify_link_ADR_req(verify_adr_params_t* verify_params, int8_t* dr,
00583                                 int8_t* tx_pow, uint8_t* nb_rep);
00584 
00585     /**
00586      * Computes the symbol time for LoRa modulation.
00587      */
00588     double compute_symb_timeout_lora(uint8_t phy_dr, uint32_t bandwidth );
00589 
00590     /**
00591      * Computes the symbol time for FSK modulation.
00592      */
00593     double compute_symb_timeout_fsk(uint8_t phy_dr);
00594 
00595     /**
00596      * Computes the RX window timeout and the RX window offset.
00597      */
00598     void get_rx_window_params(double t_symbol, uint8_t min_rx_symbols,
00599                               uint32_t rx_error, uint32_t wakeup_time,
00600                               uint32_t* window_timeout, int32_t* window_offset);
00601 
00602     /**
00603      * Computes the txPower, based on the max EIRP and the antenna gain.
00604      */
00605     int8_t compute_tx_power(int8_t txPowerIndex, float maxEirp, float antennaGain);
00606 
00607     /**
00608      * Provides a random number in the range provided.
00609      */
00610     int32_t get_random(int32_t min, int32_t max);
00611 
00612     /**
00613      * Get next lower data rate
00614      */
00615     int8_t get_next_lower_dr(int8_t dr, int8_t min_dr);
00616 
00617     /**
00618      * Get channel bandwidth depending upon data rate table index
00619      */
00620     uint8_t get_bandwidth(uint8_t dr_index);
00621 
00622     uint8_t enabled_channel_count(bool joined, uint8_t datarate,
00623                                   const uint16_t *mask, uint8_t* enabledChannels,
00624                                   uint8_t* delayTx);
00625 
00626     bool is_datarate_supported(const int8_t datarate) const;
00627 
00628 protected:
00629     LoRaRadio *_radio;
00630     LoRaWANTimeHandler &_lora_time;
00631     loraphy_params_t phy_params;
00632 };
00633 
00634 #endif /* MBED_OS_LORAPHY_BASE_ */