be up to vs request

be up to

verb
  • To do or be involved in doing; to do (often something mischievous or inappropriate). 

  • To depend on, to be the choice of. 

request

verb
  • To ask (somebody) to do something. 

  • To ask for (something). 

noun
  • A message sent over a network to a server. 

  • Act of requesting (with the adposition at in the presence of possessives, and on in their absence). 

  • Condition of being sought after. 

  • A formal message requesting something. 

How often have the words be up to and request occurred in a corpus of books? (source: Google Ngram Viewer )