SummaryThe integration of the Mobile Ad Hoc Networks (MANETs) into 4G systems will help to increase the networking flexibility and coverage of existing infrastructure networks. One of the crucial challenges is modifying existing reactive ad hoc routing protocols to support external routing operations. This paper contributes thorough protocol extensions for connecting DSR-based MANETs with the Internet (DSR-IE). DSR routing protocol is extended to effectively support External Route Discovery and External Route Maintenance functions. In particular, a novel External Route Discovery scheme, Comprehensive External Route Judgment, (CERJ) is proposed. Mobile IP is utilized to manage seamless data services. Finally, OPNET simulation models are developed to demonstrate the implementability and effectiveness of the proposed schemes.