Incorrect LoRaWAN AS923 frequency range

[ouoam]

Description of defect

Mbed-os limit AS923 frequency range to 923.00 - 928.00 MHz. But in RP002-1.0.3 LoRaWAN® Regional Parameters. AS923 frequency range is 915.00 - 928.00 MHz

This defect happen from commit 4432ad9

mbed-os/features/lorawan/lorastack/phy/LoRaPHYAS923.cpp

Line 191 in 4432ad9

static const band_t AS923_BAND0 = {100, AS923_MAX_TX_POWER, 0, 0, 0, 923000000, 928000000}; // 1.0 %

But before above commit can use 915.00-928.00 MHz

mbed-os/features/lorawan/lorastack/phy/LoRaPHYAS923.cpp

Lines 311 to 320 in 5d98839

	static bool VerifyTxFreq( uint32_t freq )
	{
	// Not checking the radio drivers here as all radio drivers
	// always return true. Just check for Asia-Pacific band here
	if( ( freq < 915000000 ) || ( freq > 928000000 ) )
	{
	return false;
	}
	return true;
	}

Another similar issues #13844

Target(s) affected by this defect ?

All LoRaWAN devices using AS923 region setting.

Toolchain(s) (name and version) displaying this defect ?

Any toolchain

What version of Mbed-os are you using (tag or sha) ?

mbed-os-6.15.0

What version(s) of tools are you using. List all that apply (E.g. mbed-cli)

Mbed Studio 1.4.3

How is this defect reproduced ?

Use AS923 region and dump channels after join when the CFList is known to contain frequencies lower than 923MHz.
More in #13844