NeTS: Small: Collaborative Research: Learning to help: Trading spectrum ownership for performance

与大多数现有的动态频谱接入（DSA）的范例，主要用户（PU）和次要用户（SU）之间强加了一个“敌人”的关系，这个项目研究了一个新的DSA范例，鼓励PU和SU互相帮助，通过交易频谱所有权，以提高整体性能。具体而言，本项目设计了两种不同的方案：（1）Give-And-Take（GAT）和（2）网络编码+次用户中继（NC+SR）。前者不需要改变PU的无线电或协议栈，而后者假设PU和SU能够执行网络编码。在GAT中，SU帮助递送PU的业务，并且作为回报，SU被允许以破坏PU的方式接入许可频谱。帮助构成“给予”部分，破坏性频谱接入构成“索取”部分。在NC+SR中，SU帮助在PU之间中继PU业务。当中继PU分组时，SU中继节点可以经由网络编码将SU分组编码到PU分组上，使得SU分组在PU分组上得到“搭便车”。GAT和NC+SR都保证PU和SU的性能得到改善。本课题主要研究这两种方案的协议设计和性能优化问题。该项目的结果预计将鼓励现有的授权用户接受DSA，以进一步提高无线网络的容量。该项目支持一个合作研究小组，并涉及研究生和本科生，特别是代表性不足的少数民族学生，在研究。

In contrast with most existing dynamic spectrum access (DSA) paradigms which impose a `foe' relationship between primary users (PUs) and secondary users (SUs), this project investigates a new DSA paradigm which encourages PUs and SUs to help each other by trading spectrum ownership for improved overall performance. Specifically, this project designs two different schemes: (1) Give-And-Take (GAT) and (2) Network Coding + Secondary User Relay (NC+SR). The former does not need to change the radio or the protocol stack of PUs, while the latter assumes that PUs and SUs are capable of performing network coding. In GAT, SUs help deliver the traffic of PUs and in return are allowed to access licensed spectrum in a manner disruptive to PUs. The help constitutes the `give' part, and the disruptive spectrum accesses constitute the `take' part. In NC+SR, SUs help relay PU traffic between PUs. When relaying PU packets, SU relay nodes may encode SU packets onto PU packets via network coding, so that SU packets get a `free ride' on PU packets. Both GAT and NC+SR promise the improved performance of PUs as well as SUs. The project studies the issues of protocol design and performance optimization of the two schemes. Results from this project are expected to encourage incumbent licensed users to embrace DSA to further improve the capacity of wireless network. The project sustains a collaborative research team, and involves both graduate and undergraduate students, particularly the underrepresented minority students,in research.