I was looking for LTE signal strength myself and found this unanswered question. Here is how I did it.
There is a string passed with the onSignalStrengthsChanged call that has a pile of numbers in it separated by spaces. Counting the word "SignalStrength:" as 0, LTE signal strength is the 8th element. I'll leave it to you on how to parse the string to just get this number.
can anyone share some sample code to get LTE parameters, how to pass the above values to get required output. all other methods are availables except LTE.