Pervasive computing offers environments in which user needs or tasks are fulfilled without demanding their attention. Context-aware service composition is a central aspect to achieving this, in which services are discovered and composed in response to context to meet user needs. Since pervasive computing environments are inherently dynamic and heterogeneous, context-aware service composition is a complex and challenging task. There are many research challenges in the field of service composition and some of them have already been met. However, from the literature we have identified some other important research challenges in service composition domain and proposed a service composition comparison framework. In this paper, we provide the review on the state-of-the-art in the field of service composition of heterogeneous services and compare them against proposed comparison framework.