지금 잠시 통화 괜찮으신가요? = Can you talk for a little while now? (expects an affirmative answer) 지금 통화하기(가) 곤란하신가요/어려우신가요? 그러시면 다음에 통화해요. (more neutral - makes it easy to decline) = Is it a bad time to talk on the phone? If so, we'll do it next time. 지금 통화하기 곤란하시면/어려우시면/불편하시면 다음에 (통화)해요. (same, in one sentence) = If it's a bad time for you to talk, we'll do it some other time. (곤란하다 = awkward/difficult, 어렵다 = difficult, 불편하다 = inconvenient/bothersome). "지금 통화하기 불편하실까요?"" is similar, but I think 하신가요 (present tense) sounds better than 하실까요? (future or tenseless possibilities) in this case. I hope that answers your question. If not, please feel free to ask again.