"I have always aspired to play in England. This chance with Sussex will provide me with a great opportunity to learn and improve," Rana told AFP ahead of Wednesday's second Test against India here.
"I heard from greats like Wasim Akram and Waqar Younis that a bowler improves by playing in England. I would love to polish my talent there."
The 27-year-old medium pacer from Sheikhupura, Pakistan, took just one wicket in the drawn first Test against India at Mohali last week.
He has taken eight wickets in four Tests and 33 wickets in 22 one-day internationals.
Rana said he will join the Sussex staff in mid-June after Pakistan completes its tour to the West Indies.
His contract is set to last until the end of the season as Pakistan do not have any international commitments before they host England in November.
Former Pakistan leg-spinner Mushtaq Ahmed also plays for Sussex.