4550
The System was heard in the United States and Canada as one of the then-ten dance/electronic music satellite channels operated by  Sirius XM Radio  which in turn operated as one of  XM Satellite Radio  's then-five dance/electronic formatted offerings broadcasting on XM channel 82 through a legacy business relationship between 1worldspace and XM .
 subsidiaries: Sirius XM Radio, XM Satellite Radio
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
 Entity Pairs:  Sirius XM Radio, XM Satellite Radio 
Answer:
 subsidiaries: Sirius XM Radio, XM Satellite Radio