中文摘要：

为实现矿井机车无人驾驶系统，必须解决机车在矿井巷道轨旁AP之间的切换时延问题。典型的切换过程包括MAC层切换和网络层切换，其中MAC层切换包括扫描、认证和重关联3个阶段，其中扫描阶段占切换时延的90％以上，传统的切换机制采用全扫描方式，时延较高，难以满足实时性应用对切换时延的要求。由于AP位置固定且机车的位置可通过定位算法获取到，因此提出基于位置的无缝切换机制，该机制在非连续多个AP出现故障情况下，根据建立的AP信息链表，都能保证机车在确定的位置选择合适的AP进行MAC层切换，在MAC层切换的同时根据网络路由的需要进行网络层切换过程。通过仿真验证表明该切换机制能够降低切换时延60％以上，实现机车在轨旁AP之间的切换延时满足实时系统对时延的要求，实现无缝切换。

英文摘要：

In order to achieve the goal of mine locomotive unmanned system , it is necessary to solve the problem of handoff delay caused by the locomotive in mine laneway move from one access point to another one .A typical handoff process includes the MAC layer handoff and the network layer handoff .And the MAC layer handoff consists of three phases： scan, authentication and re-association.More than 90%of handoff delay is caused by scan phase.The tradi-tional handoff mechanism can cause high handoff delay by using full-scan method which is difficult to meet the re-quirements of the real-time applications.Since the position of the access points is fixed and the position of the loco-motive can be obtained by positioning algorithm, Location Based Seamless Handoff Mechanism is presented to solve the problem.According to the access point information list established by the locomotive , the mechanism can ensure that the locomotive can choose the appropriate access point to make the MAC layer handoff at the specified location in the condition of discontinuous multiple access point’s failure case.According to the network route, the network layer handoff can be made at the same time .The simulation validates that the mechanism reduces at least 60% of the handoff delay.Ultimately the goal is achieved and the requirements of the delay for real-time systems are met.