煤矿井下灾后救援网络重构与应急数据流传输关键问题研究

Now available monitor networks in coal mines are mainly deployed for disaster warning. However, once coal mine disasters take place, the power system and network infrastructures will be seriously destroyed. This project proposes to utilize available wireless base stations and wireless terminals in disaster area in reconstructing the wireless emergency rescue network. And the theory of emergency data transmission will be also studied. First, we propose a topology reconstruction scheme for emergency networks based on Wi-Fi Direct protocol. And we classify the emergency data flow into the following three categories. The first is the uplink flow which is used to recover the disaster field information. The second is the intra-network flow which is used to convey information between the trapped miners and the rescue equipments. And the third is the downlink flow which is used to convey the relief information from the ground rescue system to underground trapped miners. To ensure the badly wrecked terminals can timely upload their sensing information to the secure terminals before losing the sensing ability, we propose a delay based network Quality of Service (QoS) differentiation scheme for the uplink flows. Considering most of proximate trapped miners are in need of the same relief information, we propose a Device-to-Device (D2D) based wireless multicast scheme to improve the energy efficiency for the intra-network and downlink flows. Thus, the working time of the emergency network can be prolonged to support rescue operation. The proposed coal mine rescue network has the function complementation to existing coal mine monitor networks, and they have compatible network protocols. So the cooperative operation of these two types of networks will greatly improve the safety production in coal mines.

现有的矿山监控网络以灾害预警为主,而灾害事故的发生将对井下电力系统和网络设施造成较大破坏.项目提出利用灾后可用的无线基站和终端重构覆盖灾区的应急通信网络,并研究应急数据流传输的关键问题.首先,提出基于WiFi-Direct的应急网络拓扑重构方案,并将井下应急数据流分为上行(还原灾区的现场状况),网内(协助灾区矿工和避险系统的信息交互)和下行数据流(地面救援指令向灾区的传送)三类.此后,针对上行应急数据流研究基于时延的网络QoS区分机制,使受损严重的应急终端能在其信息获取能力丧失前将感知的事故现场信息传送至安全终端.最后,考虑到相邻的被困矿工通常需要相同的救援信息,项目针对网内和下行应急数据流研究基于无线组播和D2D协作重传的能耗节省方案,延长应急网络的救援支撑时间.所研究的矿山应急网络与现有的矿山监控网络具有较大的功能互补性和协议兼容性,它们的协同工作将为煤矿井下作业提供更高的安全保障.

本项目研究煤矿井下灾后救援网络重构与应急数据流传输关键问题。首先，应用D2D中继技术改善矿井超宽带无线通信系统的误码率性能，并研究误码率最低的中继节点部署策略。研究结果说明采用所提出的最优中继节点部署策略，可以在不增加节点能量消耗的前提下将多跳D2D通信的误码率降低3~5dB。其次，研究了应急通信网络中基于时域半双工的D2D中继方案，构建基于时域半双工中继的D2D通信模式，实现了应急通信网络中D2D通信的正交信道复用，获得了比传统集中式基站通信更高的频谱利用效率和数据吞吐量。然后，研究应急通信网络中基于时域全双工的D2D中继方案，全双工中继能够实现蜂窝通信和D2D通信的共信道频谱复用，理论上能够获得比半双工中继高一倍的频谱资源利用率。所构建的基于全双工中继的D2D通信模式，实现了蜂窝通信和D2D通信的共信道复用，获得了更高的频谱利用率和数据吞吐量。接下来，研究了嵌入M2M的矿山应急网络中高能效的发射功率和传输时隙分配方案，设计了M2M群组内网关和终端的发射功率协同控制方法，减小了M2M终端的能耗并满足M2M通信的最小时延要求。最后，研究了虚拟矿山网络中基于效用函数和价格机制的频谱资源分配方案，通过迭代搜索资源分配的均衡价格，实现对VCN频谱资源的最优化分配，达到最大化CNO和VSP网络收益的目的。