This paper describes the requirements for the reliability of robot communication, which is an important issue for a practical use, especially in a loosely coupled environment, the wireless network and WAN, and explains how to resolve these issues using Web services based protocol "RoboLink Protocol". In order to achieve reliability under these communication conditions, this paper proposes to solve them by combining two solutions: one for the transport layer is adopting the standard reliable messaging technology, and the other for the application layer implements a transaction behavior, with a recovery process for fatal failures. And, it also provides a guideline for developers how to implement these recovery process easily in their application. And more, it reports the implementation strategy and the success of the verification for this solution using our proof-of-concept implementation developed as a plug-in handler of the Web server, and also provides the test cases.