"Current rate" may be given as 0xFFFFFFFF in "WDS Get Channel Rates" if "unknown" or "n/a" because this will always happen whenever there is no current network connection.

Instead of returning a data rate of 4294967295bps, we should report "unknown".

[14 2月 2019, 09:29:36] [Debug] [/dev/cdc-wdm1] received generic response (translated)...
<<<<<< QMUX:
<<<<<<   length  = 77
<<<<<<   flags   = 0x80
<<<<<<   service = "wds"
<<<<<<   client  = 34
<<<<<< QMI:
<<<<<<   flags       = "response"
<<<<<<   transaction = 1
<<<<<<   tlv_length  = 65
<<<<<<   message     = "Get Channel Rates" (0x0023)
<<<<<< TLV:
<<<<<<   type       = "Result" (0x02)
<<<<<<   length     = 4
<<<<<<   value      = 00:00:00:00
<<<<<<   translated = SUCCESS
<<<<<< TLV:
<<<<<<   type       = "Channel Rates" (0x01)
<<<<<<   length     = 16
<<<<<<   value      = FF:FF:FF:FF:FF:FF:FF:FF:80:D1:F0:08:00:CA:9A:3B
<<<<<<   translated = [ channel_tx_rate_bps = '4294967295' channel_rx_rate_bps = '4294967295' max_channel_tx_rate_bps = '150000000' max_channel_rx_rate_bps = '1000000000' ]
<<<<<< TLV:
<<<<<<   type   = 0x10
<<<<<<   length = 36
<<<<<<   value  = 02:00:00:00:FF:FF:FF:FF:00:00:00:00:FF:FF:FF:FF:00:00:00:00:00:00:00:00:00:00:00:00:E8:03:00:00:00:00:00:00

Channel data rates:
	Current TX rate: 4294967295bps
	Current RX rate: 4294967295bps
	Max TX rate:     150000000bps
	Max RX rate:     1000000000bps