Current mobile interaction is not well designed with con- sidering mobility. Usability of a mobile service is degraded while on the move, since users can not pay enough attention to the service in such a dynamic and complicated mobile context. In this paper, we propose the mobile service de- sign framework, which improves the mobility by decreasing the user's cognitive load. Our approach provides two in- teraction modes (i.e. simple interaction mode and normal interaction mode) to mobile services so that the user can retrieve important information with less attention. More- over, the service's events are simplified to support several modalities, and thus the user can be notified in the most suitable way according to the situation. In order to evaluate the feasibility of our approach through field experiments, we have developed a pedestrian navigation service as a part of the framework. The results showed that the simple interac- tion mode successfully decreased the user's attention to the service. Also, future directions for further improvements are discussed based on feedbacks from subjective comments.