NeTS: Medium: Full Duplex Wireless

无线网络假设无线电是半双工的。在给定的频率上，半双工无线电可以发送或接收，但不能同时发送和接收。该项目反驳了这一长期存在的假设;它展示了如何使用现成的商品组件构建能够在同一频率上同时发送和接收的无线电。 该设计基于两个关键思想。第一，是模拟电路的设计，其可以执行自适应信号反转，即，获取输入RF信号并产生其精确的反转，并且以编程方式调整反转信号上的衰减和延迟以匹配接收信号所经历的自干扰。 这使得宽带全双工无线电的设计，可以处理高达20 dBm的发射功率。其次，该项目利用全双工原语设计了用于控制和数据的实时双向通道，以及更复杂的模式，如链。通过在消息中散布控制和数据信息，节点可以对信道的变化做出实时的动态反应。上述两个原语-全双工操作和实时双向控制信道-可以帮助解决无线网络中许多长期存在的基本问题，包括隐藏终端、比特率自适应、网络拥塞、资源分配和不公平性。该项目将为WiFi风格的网络生产一个原型全双工无线电，并通过实验展示它如何提高其性能，此外，所有设计也将通过研究出版物和开源硬件设计公开。

Wireless networking assumes that radios are half-duplex. On a given frequency, a half-duplex radio can either transmit or receive, but not both at the same time. The project disproves this long-held assumption; it shows how a radio that can transmit and receive simultaneously on the same frequency can be built using commodity off-the-shelf components. The design is based on two key ideas. First, is the design of analog circuits that can perform adaptive signal inversion, i.e. take an input RF signal and produce its exact inverse, and programmatically adapt the attenuation and delay on the inverted signal to match the self-interference experienced by the received signal. This enables the design of wideband full duplex radios that can handle transmit powers upto 20dBm. Second, the project exploits the full duplex primitive to design a real-time bidirectional channel for control and data, as well as more complex patterns such as chains. By interspersing control and data information in a message, nodes can dynamically react to channel changes in real-time.The above two primitives - full-duplex operation and a real-time bidirectional control channel - can help solve many long-standing fundamental problems in wireless networks, including hidden terminals, bitrate adaptation, network congestion, resource allocation and unfairness. The project will produce a prototype full duplex radio for WiFi style networks and show experimentally how it can improve their performance, further all designs will also be made public through research publications and open-source hardware designs.