lwmac_internal.h

Interface definition for internal functions of LWMAC protocol.

GNRC_LWMAC_TX_CONTINUE

Flag to track if the sender can continue to transmit packet to the receiver in its TX procedure. 

1
(0x0008U)

LWMAC supports burst transmission based on the pending-bit technique. Namely, if the sender has multi packets for the same receiver, it can successively transmit its packets back to back with this flag set up, with the awareness that the receiver will also keep awake for receptions.

GNRC_LWMAC_QUIT_TX

Flag to track if the sender should quit Tx in current cycle. 

1
(0x0010U)

This flag is mainly for collision avoidance. In case a node overhears ongoing broadcast packets stream or other ongoing transmissions of other communication pairs during its wake-up period, it sets up this flag, which quits all its potential transmission attempts in this current cycle (started by the wake-up period), thus not to collide with other (neighbor) nodes’ transmissions.

GNRC_LWMAC_PHASE_BACKOFF

Flag to track if the device need to reselect a new wake-up phase. 

1
(0x0020U)

This flag is mainly for potential collision avoidance. In multi-hop scenario, it could be dangerous that a sender’s wake-up phase is close to its receiver’s, which may lead to collisions when the sender is sending to the receiver while the sender’s son nodes are also sending to the sender. To avoid this, in case a sender finds its phase close to its receiver’s, it sets up this flag and then randomly reselects a new wake-up phase.

GNRC_LWMAC_QUIT_RX

Flag to track if the device needs to quit the wake-up (listening) procedure. 

1
(0x0040U)

LWMAC adopts an auto wake-up extension scheme. That is, normally, after each data reception in the wake-up period, it extends the wake-up period to another basic duration, thus to receive more potential incoming packets, which is also correlated to the pending-bit transmission scheme to support burst transmissions to boost throughput. However, in some situations, like receiving broadcast (stream) packet, the receiver should immediately goto sleep (by setting up this flag) after one reception, thus not to receive duplicate broadcast packets.

GNRC_LWMAC_RTT_EVENT_MARGIN_TICKS

Next RTT event must be at least this far in the future. 

1
(RTT_MS_TO_TICKS(2))

When setting an RTT alarm to short in the future it could be possible that the counter already passed the calculated alarm before it could be set.

void gnrc_lwmac_set_tx_continue(gnrc_netif_t * netif, bool tx_continue)

set the lwmac_internal.h::GNRC_LWMAC_TX_CONTINUE flag of the device

Parameters

netif:ptr to the network interface
tx_continue:value for LWMAC tx-continue flag

bool gnrc_lwmac_get_tx_continue(gnrc_netif_t * netif)

get the lwmac_internal.h::GNRC_LWMAC_TX_CONTINUE flag of the device

Parameters

netif:ptr to the network interface

Return values

  • true if tx continue
  • false if tx will not continue
void gnrc_lwmac_set_quit_tx(gnrc_netif_t * netif, bool quit_tx)

set the lwmac_internal.h::GNRC_LWMAC_QUIT_TX flag of the device

Parameters

netif:ptr to the network interface
quit_tx:value for lwmac_internal.h::GNRC_LWMAC_QUIT_TX flag

bool gnrc_lwmac_get_quit_tx(gnrc_netif_t * netif)

get the lwmac_internal.h::GNRC_LWMAC_QUIT_TX flag of the device

Parameters

netif:ptr to the network interface

Return values

  • true if quit tx
  • false if will not quit tx
void gnrc_lwmac_set_phase_backoff(gnrc_netif_t * netif, bool backoff)

set the lwmac_internal.h::GNRC_LWMAC_PHASE_BACKOFF flag of the device

Parameters

netif:ptr to the network interface
backoff:value for LWMAC lwmac_internal.h::GNRC_LWMAC_PHASE_BACKOFF flag

bool gnrc_lwmac_get_phase_backoff(gnrc_netif_t * netif)

get the lwmac_internal.h::GNRC_LWMAC_PHASE_BACKOFF flag of the device

Parameters

netif:ptr to the network interface

Return values

  • true if will run phase-backoff
  • false if will not run phase-backoff
void gnrc_lwmac_set_quit_rx(gnrc_netif_t * netif, bool quit_rx)

set the lwmac_internal.h::GNRC_LWMAC_QUIT_RX flag of the device

Parameters

netif:ptr to the network interface
quit_rx:value for LWMAC lwmac_internal.h::GNRC_LWMAC_QUIT_RX flag

bool gnrc_lwmac_get_quit_rx(gnrc_netif_t * netif)

get the lwmac_internal.h::GNRC_LWMAC_QUIT_RX flag of the device

Parameters

netif:ptr to the network interface

Return values

  • true if will quit rx
  • false if will not quit rx
void gnrc_lwmac_set_dutycycle_active(gnrc_netif_t * netif, bool active)

set the sys/include/net/gnrc/lwmac/types.h::GNRC_LWMAC_DUTYCYCLE_ACTIVE flag of LWMAC

Parameters

netif:ptr to the network interface
active:value for LWMAC sys/include/net/gnrc/lwmac/types.h::GNRC_LWMAC_DUTYCYCLE_ACTIVE flag

bool gnrc_lwmac_get_dutycycle_active(gnrc_netif_t * netif)

get the sys/include/net/gnrc/lwmac/types.h::GNRC_LWMAC_DUTYCYCLE_ACTIVE flag of LWMAC

Parameters

netif:ptr to the network interface

Return values

  • true if active
  • false if not active
void gnrc_lwmac_set_reschedule(gnrc_netif_t * netif, bool reschedule)

set the sys/include/net/gnrc/lwmac/types.h::GNRC_LWMAC_NEEDS_RESCHEDULE flag of LWMAC

Parameters

netif:ptr to the network interface
reschedule:value for sys/include/net/gnrc/lwmac/types.h::GNRC_LWMAC_NEEDS_RESCHEDULE flag

bool gnrc_lwmac_get_reschedule(gnrc_netif_t * netif)

get the sys/include/net/gnrc/lwmac/types.h::GNRC_LWMAC_NEEDS_RESCHEDULE flag of LWMAC

Parameters

netif:ptr to the network interface

Return values

  • true if needs rescheduling
  • false if no need for rescheduling
int _gnrc_lwmac_transmit(gnrc_netif_t * netif, include/net/gnrc/pkt.h::gnrc_pktsnip_t * pkt)

send a packet over the network interface in LWMAC

int _gnrc_lwmac_parse_packet(include/net/gnrc/pkt.h::gnrc_pktsnip_t * pkt, gnrc_lwmac_packet_info_t * info)

Parse an incoming packet and extract important information.

Copies addresses into info, but header points inside pkt.

Parameters

pkt:packet that will be parsed
info:structure that will hold parsed information

Return values

  • 0 if correctly parsed
  • <0 on error
netopt.h::netopt_state_t _gnrc_lwmac_get_netdev_state(gnrc_netif_t * netif)

Shortcut to get the state of netdev.

Parameters

netif:ptr to the network interface

Return values

  • state of netdev
void _gnrc_lwmac_set_netdev_state(gnrc_netif_t * netif, netopt.h::netopt_state_t devstate)

Shortcut to set the state of netdev.

Parameters

netif:ptr to the network interface
devstate:new state for netdev

uint32_t _gnrc_lwmac_ticks_to_phase(uint32_t ticks)

Convert RTT ticks to device phase.

Parameters

ticks:RTT ticks

Return values

  • device phase
uint32_t _gnrc_lwmac_phase_now(void)

Get device’s current phase.

Return values

  • device phase
uint32_t _gnrc_lwmac_ticks_until_phase(uint32_t phase)

Calculate how many ticks remaining to the targeted phase in the future.

Parameters

phase:device phase

Return values

  • RTT ticks
int _gnrc_lwmac_dispatch_defer(include/net/gnrc/pkt.h::gnrc_pktsnip_t * buffer, include/net/gnrc/pkt.h::gnrc_pktsnip_t * pkt)

Store the received packet to the dispatch buffer and remove possible duplicate packets.

Parameters

buffer:RX dispatch packet buffer
pkt:received packet

Return values

  • 0 if correctly stored
  • <0 on error
struct gnrc_lwmac_packet_info_t

Type to pass information about parsing.

gnrc_lwmac_hdr_t * header

LWMAC header of packet.

gnrc_lwmac_l2_addr_t src_addr

copied source address of packet

gnrc_lwmac_l2_addr_t dst_addr

copied destination address of packet