In this article, we study a generalized version of the maximum independent set and minimum dominating set problems, namely, the maximum d-distance independent set problem and the minimum d-distance dominating set problem on unit disk graphs for a positive integer d > 0. We first show that the maximum d-distance independent set problem and the minimum d-distance dominating set problem belongs to NP-hard class. Next, we propose a simple polynomial-time constant-factor approximation algorithms and PTAS for both the problems.