地空协同传输理论与方法

关新平　陈彩莲　化存卿　张有光　高强

摘要：本研究针对我国中长期科技发展规划对大型飞机的重大战略需求，研究飞行器在复杂条件下进近可视导航所需的空地通信网络基础科学问题。根据飞行器在不同飞行阶段的运动特点及对通信的需求差异，本研究从两个方面展开研究：巡航区飞行器的混合式地空蜂窝网络；进近飞行器可靠通信的机场终端区无线mesh网络。重点研究了网络的基本组成和实现机理，并进行大规模的试验和验证；为可视导航技术创新提供基础理论支持。 在混合式地空蜂窝网络架构中，空中飞行器组成自组织网络，地面VHF基站与区域管制中心联网，整合所有导航、管制及服务相关信息。飞行器可与地面VHF基站通信，获取所有与安全飞行相关的信息，并及时向地面提供自身的飞行数据；飞行器之间可自由通信，保证周围态势信息的及时获取，缩小安全间隔，减少基站通信负荷。为建立具有可扩展、可重构特性的空地协同传输体系，本研究围绕该混合式地空蜂窝网络架构，本研究着重研究了网络系统容量分析方法及异构网络下多域协同编码技术，提出网络系统容量分析方法。优化空地数据链网络结构，获得较高传输可靠性和较强复用能力，提高系统容量。 另一方面，在全天候、高交通密度和各种复杂的机场建筑布局情况下，保证飞行器和地面车辆在机场的安全、有序及快速运行是机场运行的重要目标，也是提高机场对飞行器架次的处理能力、效率及安全的先决条件。因此，本研究在机场表面建立的无线mesh网络利用运行在场面上的飞行器、车辆、地勤人员及场面设备等作为通信节点，并在跑道周边布设传感器节点等，旨在快速、准确地传输塔台对飞行器、车辆和地面人员的指挥调度信息。利于实现安全、高效、高速、有序的民航航站空侧交通管理工作，在全天候条件下能够对航站交通进行科学的管理。由于机场终端区存在各种复杂的机场建筑，使得机场表面无线通信受多径效应干扰严重，因此本研究采用协作通信技术，利用场面塔台和目标节点间的空闲节点进行信号的中继转发，有效提高传输的可靠性。同时，为满足突发事件报告对传输实时性的要求，提出了基于虚拟Agent 的事件报告传输机制，有效减小传输时延。

关键词：空地数据链系统；航空自组网；网络容量；可扩展性；异构信息传输；协作通信

Abstract：In this project， we propose an Aeronautical Ad-hoc network （AANET） architecture based on several ？ight paths， whereby the aircrafts in the cruise stage can get the information from the ground with the aid of ground stations and aircrafts can communicate with each other through multi-hop relays for information sharing and critical situational awareness. To improve the scalability and reconfiguration capability of the air-ground communication system， we investigate the method of analyzing the network capacity and propose a multi-domain collaborative network coding technology for heterogeneous information transmission. Due to the special structure of AANET， existing results on conventional mobile ad hoc networks are not applicable for determining the capacity scaling law of this network model. We prove an upper bound on the per-node capacity and construct a simple transmission scheduling scheme to achieve the lower bound， in this way， the capacity of the AANET is derived. The reason for the construction of the Airport Surface Wireless Mesh networks comes from several aspects. Top of the list comes lack of flexibility in existing airport communications infrastructure and underground cabling is expensive to deploy. Particularly， most of the aging infrastructures are costly to maintain and vulnerable； also， existing cabling infrastructure are not always available at all airports； the integration of communication is limited， resulting the lack of network connectivity. Moreover， current NAS modernization and anticipated “NextGen” Air Traffic System increase demands for CNS information sharing stakeholders. Therefore， Airport Surface Wireless Mesh networks integrates data from existing airport infrastructures， such as ASDE-X sensors， runway incursion prevention system， weather and wake sensors， constructing an information pool that can be used for controllers， pilots， airlines， ramp， deicing as well as service and emergency dispatch， et al. As a consequence， wireless mobile airport surface communications can greatly benefits the reliability， secure integration of voice/video/data at all airport locations. And enables “SWIM” networked integration of data sources and users， allows flexible， expandable， affordable deployment at airports of all sizes， while at the same time reduces VHF spectrum congestion.

Keywords：air-ground data link system； aeronautical ad-hoc network； network capacity； scalability； heterogeneous information transmission； cooperative communication