Research of next generation LEO satellite networks which have high affinity with the Internet

近年来，许多研究人员研究了无处不在的网络，它允许所有用户在任何时间、任何地点访问任何类型的信息。在这些网络中，低地球轨道卫星网络预计将发挥关键作用，主要是由于它们的低传播延迟。本研究的目的是研究与互联网有高度亲和力的下一代近地轨道卫星网络的基础技术。我们按照原计划研究了以下四项基础技术：低轨道卫星直接与地面终端通信。由于低轨道卫星移动速度快，切换频繁，移动管理包生成频繁。因此，无线电资源被浪费了。为此，我们提出了一种基于地理信息和LEO卫星轨道的低成本移动管理技术。在低轨卫星网络中应用TCP/IP协议，由于存在传输延迟等现象，难以实现效率和公平性。因此，我们提出了一种强调效率和公平性的协议。该协议可以通过卫星跳数来预测往返时间，从而计算出合适的数据速率。为了在低轨道卫星网络中提出一种安全技术，我们提出了一种减少路由攻击对自组织网络影响的方案。我们需要在未来的低轨道卫星网络中扩展这一方案。我们提出了一种交通控制方案，使相邻的卫星能够明确地交换有关其拥塞状态的信息。在这种方案中，流量负荷是分散的，这样就不会把它集中在某一颗卫星上。上述提出的方案为下一代LEO卫星网络系统奠定了基础，并将为实现无缝网络环境做出重大贡献。从而达到了本研究的目的。

In recent years, a lot of researchers have studied ubiquitous networks that allow all users to access information of any kind at any time, from anywhere. In those networks, LEO (Low Earth Orbit) satellite networks are expected to play a key role, mainly due to their low propagation delay. The purpose of this research is to study fundamental technologies in nest generation LEO satellite networks which have high affinity with the Internet. We researched the four following fundamental technologies as originally planned:1. LEO satellites communicate directly with ground terminals. Since LEO satellites move quickly, handover occurs frequently and mobility management packets are generated often. As a result, radio resources are wasted. So, we proposed a low-cost mobility management technology based on geographic information and LEO satellite orbit.2. If TCP/IP is applied to LEO satellite networks, efficiency and fairness are difficult to achieve due to propagation delay and other phenomenon. So we proposed a high efficiency and fairness emphasizing protocol. This protocol enables calculation of a suitable data rate with predicting round trip time by satellite hop counts.3. To propose a security technology on LEO satellite networks, we proposed a scheme that reduces the impact of routing attack on ad-hoc networks. We need to extend this scheme for LEO satellite networks in the future.4. We proposed a traffic control scheme that enables neighboring satellites to explicitly exchange information on their congestion status. In this scheme, traffic load is distributed so as not to concentrate it on any certain satellite.The above proposed schemes serve as a foundation for the next generation LEO satellite network system, and will contribute largely to the implementation of a seamless network environment. Therefore, the purpose of this research was accomplished.