ATL: an adaptive transport layer suite for next-generation wireless Internet

The next-generation wireless Internet (NGWI) is expected to provide a wide range of services including high-speed data and real-time multimedia to mobile users. To realize this expectation, a diverse set of challenges need to be addressed, which are posed by heterogeneous wireless networking environments within NGWI and the according application requirements. Furthermore, the architectural heterogeneities must be captured dynamically, while mobile users may roam during their connection duration. Current existing transport layer protocols have been developed for a specific network paradigm in mind, e.g., for wireless local area networks (WLANs), micro/macro wireless systems, or for satellite systems. Using these existing different transport layer protocols for NGWI to support global roaming of mobile users is not a practical solution due to processing and memory constraints of wireless terminals. Thus, there is a need for a unified adaptive transport layer protocol suite which can address the architectural heterogeneities for roaming mobile users and achieve the best performance for NGWI. In this paper, a unified adaptive transport layer (ATL) suite is introduced for NGWI which incorporates a new adaptive transport protocol (TCP-ATL) for reliable data transport and a new adaptive rate control protocol (RCP-ATL) for multimedia delivery in the NGWI. According to the requested service type, i.e., reliable data or multimedia, ATL selects the appropriate protocol. Both TCP-ATL and RCP-ATL, deploy a new adaptive congestion control method that dynamically adjusts the protocol configurations according to the current wireless network paradigms depending where the mobile user currently resides. Hence, the unified adaptive ATL protocol suite achieves high-throughput performance in all of underlying heterogeneous wireless architectures, i.e., WLANs, micro, macro, or satellite environments. Moreover, the developed adaptive congestion control explicitly takes fairness into consideration. Performance evaluation via simulation experiments reveals that the ATL protocol suite addresses the challenges posed by the NGWI and significantly improves the performance for reliable data and multimedia transport in NGWI.