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为旅客列车乘务员配备备用公共地址(PA)通信系统,建立与旅客之间的通信联系是可行的。当发生紧急情况(碰撞、脱轨等),列车通信线路遭到破坏时,装备了PA/对讲电话系统的铁路旅客车厢失去了与整个列车的通信能力。这时,要求列车乘务员必须能够与旅客建立联系,向旅客说明情况,消除恐慌,避免发生对旅客和列车乘务人员造成伤害或带来其他危险的情况。美国联邦铁路局(FRA)资助了一个小企业创新研究(SBIR)项目,对铁路旅客车厢内配备备用通信系统,以便在发生列车通信线路遭受破坏或中断时发挥通信联系作用的可行性进行研究。该备用系统的供电将独立于车厢电池装置,从列车通信线路遭到破坏的那一时刻开始,可满足1小时的通话。列车乘务员及急救人员可利用手持装置通过该系统在一定的范围内从车厢内或车厢外向旅客发出指令。DFuzion,Inc.公司被指定对其建议使用的旅客无线通信系统(WPCS)的开发进行研究。WPCS通过802.11x Wi-Fi网格技术,在整个列车编组上建立容错、自修复、安全、无线移动的网格网络。WPCS利用基于网格协议的手持无线装置,通过车内无线网络接入点,最终与旅客建立联系。WPCS由可充式直流电源供电。直流电源由列车主电源充电,当失去列车主电源时,系统仍能继续工作。WPCS概念的可行性通过了多次计算机模拟试验的验证(图1),当列车通信线路网络需要服务器支持或网格网络节点被破坏时,该无线网格网络整体上能继续工作。
It is feasible to equip Passenger Train Crew with a backup public address (PA) communication system to establish communication with passengers. When an emergency (collision, derailment, etc.) occurs and the train communication line is destroyed, the railway passenger car equipped with a PA / intercom system loses its ability to communicate with the entire train. At this time, train attendants must be able to establish contact with passengers, explain the situation to passengers, eliminate panic and avoid causing injury or other hazards to passengers and train crew. The United States Federal Railroad Agency (FRA) funded a small business innovation research (SBIR) project to equip railroad passenger wagons with back-up communication systems to investigate the feasibility of communicating in the event of train lines being destroyed or disrupted. The backup system’s power supply will be independent of the compartment battery device, from the moment the train communication line is destroyed, to meet the 1 hour call. Train attendants and emergency responders can use the handheld device to issue commands to passengers from within the car or outside of the car within a certain range. DFuzion, Inc. was designated to study the development of its proposed Passenger Wireless Communication System (WPCS). WPCS uses 802.11x Wi-Fi grid technology to create fault-tolerant, self-healing, secure, wireless mobile mesh networks throughout the train fleet. WPCS utilizes a hand-held wireless device based on a mesh protocol to ultimately connect with travelers through in-vehicle wireless network access points. WPCS is powered by a rechargeable DC power supply. The DC power is charged by the main power of the train. When the main power of the train is lost, the system can still work. The feasibility of the WPCS concept has been verified by numerous computer simulations (Fig. 1), which will continue to work as a whole when the train communication line network requires server support or the mesh network node is destroyed.