This class encapsulates/stores all relevant information about quality of a link, including average received signal strength (RSS), last RSS, link margin, and link quality. More...

#include <src/core/thread/link_quality.hpp>

Public Types
enum	{ kInfoStringSize = 50 }

Public Member Functions
	LinkQualityInfo (void)
	This constructor initializes the object.

void	Clear (void)
	This method clears the all the data in the object.

void	AddRss (int8_t aNoiseFloor, int8_t aRss)
	This method adds a new received signal strength (RSS) value to the average. More...

int8_t	GetAverageRss (void) const
	This method returns the current average signal strength value. More...

uint16_t	GetAverageRssRaw (void) const
	This method returns an encoded version of current average signal strength value. More...

const char *	ToInfoString (char *aBuf, uint16_t aSize) const
	This method converts the link quality info to NULL-terminated info/debug human-readable string. More...

uint8_t	GetLinkMargin (int8_t aNoiseFloor) const
	This method returns the link margin. More...

uint8_t	GetLinkQuality (void) const
	Returns the current one-way link quality value. More...

int8_t	GetLastRss (void) const
	Returns the most recent RSS value. More...

Static Public Member Functions
static uint8_t	ConvertRssToLinkMargin (int8_t aNoiseFloor, int8_t aRss)
	This method converts a received signal strength value to a link margin value. More...

static uint8_t	ConvertLinkMarginToLinkQuality (uint8_t aLinkMargin)
	This method converts a link margin value to a link quality value. More...

static uint8_t	ConvertRssToLinkQuality (int8_t aNoiseFloor, int8_t aRss)
	This method converts a received signal strength value to a link quality value. More...

static int8_t	ConvertLinkQualityToRss (int8_t aNoiseFloor, uint8_t aLinkQuality)
	This method converts a link quality value to a typical received signal strength value . More...

Detailed Description

This class encapsulates/stores all relevant information about quality of a link, including average received signal strength (RSS), last RSS, link margin, and link quality.

Member Enumeration Documentation

§ anonymous enum

anonymous enum

Enumerator

kInfoStringSize

Max chars needed for the info string representation (.

See also: ToInfoString())

Member Function Documentation

§ AddRss()

void ot::LinkQualityInfo::AddRss	(	int8_t	aNoiseFloor,
		int8_t	aRss
	)

This method adds a new received signal strength (RSS) value to the average.

Parameters

[in]	aNoiseFloor	The noise floor value (in dBm).
[in]	aRss	A new received signal strength value (in dBm) to be added to the average.

§ ConvertLinkMarginToLinkQuality()

uint8_t ot::LinkQualityInfo::ConvertLinkMarginToLinkQuality ( uint8_t aLinkMargin )

static

This method converts a link margin value to a link quality value.

Parameters

[in] aLinkMargin The Link Margin in dB.

Returns: The link quality value (0-3).

§ ConvertLinkQualityToRss()

int8_t ot::LinkQualityInfo::ConvertLinkQualityToRss	(	int8_t	aNoiseFloor,
		uint8_t	aLinkQuality
	)

static

This method converts a link quality value to a typical received signal strength value .

Note: only for test

Parameters

[in]	aNoiseFloor	The noise floor value (in dBm).
[in]	aLinkQuality	The link quality value in [0, 3].

Returns: The typical platform rssi.

§ ConvertRssToLinkMargin()

uint8_t ot::LinkQualityInfo::ConvertRssToLinkMargin	(	int8_t	aNoiseFloor,
		int8_t	aRss
	)

static

This method converts a received signal strength value to a link margin value.

Parameters

[in]	aNoiseFloor	The noise floor value (in dBm).
[in]	aRss	The received signal strength value (in dBm).

Returns: The link margin value.

§ ConvertRssToLinkQuality()

uint8_t ot::LinkQualityInfo::ConvertRssToLinkQuality	(	int8_t	aNoiseFloor,
		int8_t	aRss
	)

static

This method converts a received signal strength value to a link quality value.

Parameters

[in]	aNoiseFloor	The noise floor value (in dBm).
[in]	aRss	The received signal strength value (in dBm).

Returns: The link quality value (0-3).

§ GetAverageRss()

int8_t ot::LinkQualityInfo::GetAverageRss ( void ) const

inline

This method returns the current average signal strength value.

Returns: The current average value or OT_RADIO_RSSI_INVALID if no average is available.

§ GetAverageRssRaw()

uint16_t ot::LinkQualityInfo::GetAverageRssRaw ( void ) const

inline

This method returns an encoded version of current average signal strength value.

The encoded value is the average multiplied by a precision factor (currently -8).

Returns: The current average multiplied by precision factor or zero if no average is available.

§ GetLastRss()

int8_t ot::LinkQualityInfo::GetLastRss ( void ) const

inline

Returns the most recent RSS value.

Returns: The most recent RSS

§ GetLinkMargin()

uint8_t ot::LinkQualityInfo::GetLinkMargin ( int8_t aNoiseFloor ) const

inline

This method returns the link margin.

The link margin is calculated using the link's current average received signal strength (RSS) and average noise floor.

Parameters

[in] aNoiseFloor The noise floor value (in dBm).

Returns: Link margin derived from average received signal strength and average noise floor.

§ GetLinkQuality()

uint8_t ot::LinkQualityInfo::GetLinkQuality ( void ) const

inline

Returns the current one-way link quality value.

The link quality value is a number 0-3.

The link quality is calculated by comparing the current link margin with a set of thresholds (per Thread spec). More specifically, link margin > 20 dB gives link quality 3, link margin > 10 dB gives link quality 2, link margin > 2 dB gives link quality 1, and link margin below or equal to 2 dB yields link quality of 0.

In order to ensure that a link margin near the boundary of two different link quality values does not cause frequent changes, a hysteresis of 2 dB is applied when determining the link quality. For example, the average link margin must be at least 12 dB to change a quality 1 link to a quality 2 link.

Parameters

[in] aNoiseFloor The noise floor value (in dBm).

Returns: The current link quality value (value 0-3 as per Thread specification).

§ ToInfoString()

const char * ot::LinkQualityInfo::ToInfoString	(	char *	aBuf,
		uint16_t	aSize
	)		const

This method converts the link quality info to NULL-terminated info/debug human-readable string.

Parameters

[out]	aBuf	A pointer to the string buffer.
[in]	aSize	The maximum size of the string buffer.

Returns: A pointer to the char string buffer.

The documentation for this class was generated from the following files:

src/core/thread/link_quality.hpp
src/core/thread/link_quality.cpp

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

§ anonymous enum

Member Function Documentation

§ AddRss()

§ ConvertLinkMarginToLinkQuality()

§ ConvertLinkQualityToRss()

§ ConvertRssToLinkMargin()

§ ConvertRssToLinkQuality()

§ GetAverageRss()

§ GetAverageRssRaw()

§ GetLastRss()

§ GetLinkMargin()

§ GetLinkQuality()

§ ToInfoString()