Many network applications, e.g., industrial control, demand Ultra-Low Latency (ULL). However, traditional packet networks can only reduce the end-to-end latencies to the order of tens of milliseconds. The IEEE 802.1 Time Sensitive Networking (TSN) standard and related research studies have sought to provide link layer support for ULL networking, while the emerging IETF Deterministic Networking (DetNet) standards seek to provide the complementary network layer ULL support. This article provides an up-to-date comprehensive survey of the IEEE TSN and IETF DetNet standards and the related research studies. The survey of these standards and research studies is organized according to the main categories of flow concept, flow synchronization, flow management, flow control, and flow integrity. ULL networking mechanisms play a critical role in the emerging fifth generation (5G) network access chain from wireless devices via access, backhaul, and core networks. We survey the studies that specifically target the support of ULL in 5G networks, with the main categories of fronthaul, backhaul, and network management. Throughout, we identify the pitfalls and limitations of the existing standards and research studies. This survey can thus serve as a basis for the development of standards enhancements and future ULL research studies that address the identified pitfalls and limitations.

KEYWORDS dynamic surface control (DSC), explosion of complexity, extended state observer (ESO), quadrotor unmanned aerial vehicle (UAV), unmeasurable velocity statesRecently, the control of a quadrotor unmanned aerial vehicle (UAV) has received considerable attention from the research community due to its significant characteristics in rapid maneuverability, precise hovering, and low-cost manufacturability with reduced mechanical complexity, thereby providing a well-suited mission platform for a variety of applications from military and civilian scenarios, including small-area monitoring, surveillance, detection in restricted terrains, and reconnaissance and mapping after disasters. [1][2][3] However, how to develop an effective robust flight controller that performs well in practice while ensuring asymptotic stability in theory is still a significant challenge because of the following essential reasons. 4 (i) The quadrotor UAV only 2700 Damping matrices = diag(k x ,k y ,k z ) = diag(0.01, 0.01, 0.01) Nms 2 = diag(k ,k ,k ) = diag(0.012, 0.012, 0.012) Nms 2 J Inertial matrix J = diag(J 1 ,J 2 ,J 3 ) = diag(0.016, 0.016, 0.016) kgm 2 l Distance from each rotor 0.4 m to the center of mass c Force-to-moment factor 0.05

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