CSMA/CA helper

This interface allows code from layer 2 (MAC) or higher to send packets with CSMA/CA, whatever the abilities and/or configuration of a given radio transceiver device are. More...

Detailed Description

This interface allows code from layer 2 (MAC) or higher to send packets with CSMA/CA, whatever the abilities and/or configuration of a given radio transceiver device are.

Modules
	CSMA/CA helper compile configurations

Files
file	csma_sender.h
	Interface definition for the CSMA/CA helper.

Data Structures
struct	csma_sender_conf_t
	Configuration type for backoff. More...

Functions
int	csma_sender_csma_ca_send (netdev_t *dev, iolist_t *iolist, const csma_sender_conf_t *conf)
	Sends a 802.15.4 frame using the CSMA/CA method.
int	csma_sender_cca_send (netdev_t *dev, iolist_t *iolist)
	Sends a 802.15.4 frame when medium is available.

Variables
const csma_sender_conf_t	CSMA_SENDER_CONF_DEFAULT
	Default configuration.

Function Documentation

csma_sender_cca_send()

int csma_sender_cca_send	(	netdev_t *	dev,
		iolist_t *	iolist
	)

Sends a 802.15.4 frame when medium is available.

Precondition

dev != NULL

This function is useful for sending packets without the whole CSMA/CA procedure, but after ensuring medium is available, that is after a successful CCA.

It is especially useful for broadcasting specific packets, like beacons; or for many sending packets in burst.

Warning

ATTENTION: It only tries to send the given data once. If you want the complete CSMA/CA procedure with retries, use csma_sender_csma_ca_send().

Parameters

[in]	dev	netdev device, needs to be already initialized
[in]	iolist	pointer to the data

Returns

number of bytes that were actually send out

-ENODEV if dev is invalid

-ENOMSG if pkt is invalid

-EOVERFLOW if the payload size of pkt exceeds the payload size that can be handled by the device

-ECANCELED if an internal driver error occurred

-EBUSY if radio medium was not available to send the given data

csma_sender_csma_ca_send()

int csma_sender_csma_ca_send	(	netdev_t *	dev,
		iolist_t *	iolist,
		const csma_sender_conf_t *	conf
	)

Sends a 802.15.4 frame using the CSMA/CA method.

Precondition

dev != NULL

If the transceiver can (and is configured to) do hardware-assisted CSMA/CA, this feature is used. Otherwise, a software procedure is used.

Parameters

[in]	dev	netdev device, needs to be already initialized
[in]	iolist	pointer to the data
[in]	conf	configuration for the backoff; will be set to CSMA_SENDER_CONF_DEFAULT if NULL.

Returns

number of bytes that were actually send out

-ENODEV if dev is invalid

-ENOMSG if pkt is invalid

-EOVERFLOW if the payload size of pkt exceeds the payload size that can be handled by the device

-ECANCELED if an internal driver error occurred

-EBUSY if radio medium never was available to send the given data