RTNS is a friendly conference with a great sense of community that presents excellent opportunities for collaboration. The purpose of the conference is to share ideas, experiences and informations among academic researchers, developers and service providers in the field of real-time systems and networks. RTNS 2013 will be in Sophia Antipolis which is located on the French Riviera, close to Nice (28km), Cannes (12km) and Antibes (8km). RTNS 2013 is the 21st edition of the conference formerly known as RTS (Real-Time Systems, Paris). The first 12 editions of RTS were french-speaking events held in Paris in conjunction with the RTS Embedded System exhibition. Since its 13th edition, the conference language of RTNS has been english.