New combined WiMAX/DSRC infrastructure design for efficient vehicular networking

Abstract

Abstract In this article, a new infrastructure of a combined Worldwide Interoperability for Microwave Access (WiMAX) and Dedicated Short-Range Communications (DSRC) link layer is proposed with the purpose of reducing simultaneous WiMAX connections. WiMAX offers wide area connectivity of vehicles to ground-based base stations, while DSRC offers relatively shorter communication that allows for vehicles in proximity of each other to communicate directly. The proposed design uses the fact that WiMAX amendments support the concept of a WiMAX relay node, and substitutes the WiMAX relay nodes with nodes that are capable of both WiMAX and DSRC communications. This change allows for the number of WiMAX connections to be concentrated while supporting more subscribing users via WiMAX tunnelled over DSRC relay. The focus of this design is on the use case of providing broadband Internet access to a large number of DSRC capable vehicles in a WiMAX served region. The design uses DSRC as a WiMAX tunnel, but with changes to the WiMAX protocol, specifically network entry and handover processes are redesigned to have different behaviour only when operating over DSRC. Network entry over DSRC modifications are described and illustrated with comparison to existing WiMAX standards. Handover process facilitated over both WiMAX and DSRC layers are described, illustrated and are also standard compliant. Unified modeling language is used to assist with the explanations of the components to improve understanding of the design in relation to existing WiMAX standards. In addition to standard WiMAX operability, the design can also support WiMAX data subscription using a software-defined WiMAX radio via DSRC relay connectivity. This proposed design improves WiMAX communication by reducing the number of WiMAX connections between vehicles. We plotted the throughput of various cluster sizes of WiMAX only mobile relay, versus our proposed DSRC-enabled WiMAX mobile relay in order to show the efficiency benefit of our design. We also provide a simulated curve of percentage improvement efficiency for varying amount of active users. We show that as the total number of users in the system increases, our proposed system significantly improves the overall system efficiency, especially in heavily congested traffic.