Differences between のに, 関わらず, にも関わらず, and のにも関わらず


In this sentence:

> だれとも電話をする必要がない **のにも関わらず** 、私はその小さな物体が欲しくてたまらなかったものだ。

How can I parse のにも関わらず?  
I know にも関わらず means "in spite of" but so does のに and 関わらず. So why use の in
にも関わらず?

Also, what is the function of も in this sentence?




Whether it has も makes important difference. (noun)に関わらず means "regardless of
(noun)" while (noun/stem of na-adj, verb, i-adj)にも関わらず means "in spite of", as
is already mentioned.

As for の, you need it to norminalize a verb when it connects to に関わらず, and
it's virtually optional when it comes to にも関わらず. However you can rephrase
interrogative clauses like 行くか行かないかに関わらず as 行く行かないに関わらず.




Whether it has も makes important difference. (noun)に関わらず means "regardless of
(noun)" while (noun/stem of na-adj, verb, i-adj)にも関わらず means "in spite of", as
is already mentioned.

As for の, you need it to norminalize a verb when it connects to に関わらず, and
it's virtually optional when it comes to にも関わらず. However you can rephrase
interrogative clauses like 行くか行かないかに関わらず as 行く行かないに関わらず.

