RFID Security Solution And Vertical Handoff Algorithms For EXPO Application

In this paper, we discuss the RFID security solution and mobile node'svertical handoff algorithms in heterogeneous wireless networks based on the2010 EXPO application system. RFID is now widely deployed in variousareas, such as manufacture, military, logistics and daily life. But theinformation is transmitted by air, which issues a great challenge on privacyand security of RFID system. We fist review the existing RFID systemsecurity mechanisms,with a focus on cryptographic mechanism.Weaknesses or flaws in these protocols are examined．Then, we propose a bidirectionalauthentication with alias mechanism. This mechanism providesboth forward and backward security, and is easy to implement with low cost.The paper also analyze the system performance from security, computationcomplexity, resource requirement, all of which indicate that this is anapplicable RFID security solution.On the other hand, to evaluate the performance of the existing verticalhandoff algorithms in heterogeneous wireless networks, we establish a set ofperformance evaluation models based on mobile node's different motionmodels. Also, matching rate and ping-pong rate are chosen to be the majortwo metrics to evaluate the performance of the vertical handoff algorithms.After that, based on the proposed models and metrics, we compare theperformance of two existing vertical handoff algorithms: hysteresisalgorithm and dwelling-timer algorithm. According to the simulation results,we discuss the advantages and drawbacks of the existing algorithm.Moreover, we propose a novel vertical handoff algorithm, dynamic DTalgorithm based on the mobile node's motion history. In this algorithm, weintroduce and define ping-pong evading period, and the triggering thresholdcan be adjusted adaptively according to the trend of mobile node's motion. Then we evaluate the performance of the new algorithm at the samesimulation platform. Although the new algorithm can achieve betterperformance at low speed scenarios, the improvement at relatively highspeed scenarios is limited. We find that the major factor which limits theimprovement is the dichotomy of increasing the matching rate anddecreasing the ping-pong rate under the same triggering threshold.Therefore, we introduced dual-decision process to modify the dynamicDT algorithm. The revised algorithm uses different processes to adjust thetriggering threshold according to the state whether mobile node is in pingpongevading period. The simulation results show that the performance ofthe rived algorithm is much better at both low and high speed and it meets theneeds of the application in EXPO scenariosFinally, we conclude the results and analysis of the whole thesis, andsome prospects are presented.