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With the advancement of information technology, the traffic and scale of airborne networks, especially the military airborne networks, are growing rapidly. How to efficiently schedule the airborne network traffic to improve the bandwidth utilization and meet the quality of service (QoS) needs of different services have become an urgent issue to be addressed. Software-defined networking (SDN) is a new network paradigm, which completely separates the network control plane and data plane, and controls the network logically. With these new features, it is possible for SDN to control network flows with higher efficiency and flexibility. However, existing airborne network equipment does not support the SDN technology, and it is difficult to upgrade the equipment in a short period. Therefore, it becomes necessary to study the traffic scheduling method considering a heterogeneous scenario with the coexistence of SDN airborne nodes and traditional IP-based airborne nodes. This paper puts forward a dynamic traffic scheduling algorithm for heterogeneous software-defined airborne network, which can improve the bandwidth utilization and network transmission efficiency of airborne networks.

In this paper, the performances of mixed free-space optical (FSO)/radio frequency (RF) systems are presented based on the decode-and-forward relaying. The Exponentiated Weibull fading channel with pointing error effect is adopted for the atmospheric fluctuation of FSO channel and the RF link undergoes the Nakagami-m fading. We derived the analytical expression for cumulative distribution function (CDF) of equivalent signal-to-noise ratio (SNR). The novel mathematical presentations of outage probability and average bit-error-rate (BER) are developed based on the Meijer's G function. The analytical results show an accurately match to the Monte-Carlo simulation results. The outage and BER performance for the mixed system by decode-and-forward relay are investigated considering atmospheric turbulence and pointing error condition. The effect of aperture averaging is evaluated in all atmospheric turbulence conditions as well.

Aiming at the problem of the effective connectivity of a large number of mobile combat units in the future aeronautic swarm operation, this paper proposes an idea of using UAV(Unmanned Aerial Vehicle) to build, and studies the deployment of the network. User coverage and network connectivity are important for a relay network planning which are studied separately in traditional ways. In order to effectively combine these two factors while the network’s survivability is taken into account. Firstly, the concept of node aggregation degree is proposed. Secondly, a performance evaluation parameter for UAV relay network is proposed based on node aggregation degree, then analyzes the lack of deterministic deployment and presents one a PSO (VFA-PSO) deployment algorithm based on virtual force. Finally, compared with the existing algorithms, the validity and stability of the algorithm are verified. The experimental results show that the VFA-PSO algorithm can effectively improve the network coverage and the survivability of the network under the premise of ensuring the network connectivity, and has better deployment effect.

A 3×10 12 n/s source of 14 MeV neutrons is described in this paper. The neutrons are produced by the T(d,n) 4 He reaction under a 30 mA, 300 keV deuteron beam bombarding a water-cooled, rotating titanium-tritide target. The size of the beam spot on the target is 1.8 cm, and at the distance of closest approach to the source a neutron flux of 5×10 11 n/cm 2 s is obtained.

This paper describes a new type of electron and ion source under low gas pressure. Pulsed electron beams with a current density greater than 106A/cm2 with total current up to several hundred amperes and pulsed ion beams of the order of amperes were produced by this device. A model of the field escalation effect is proposed to explain the discharge mechanism in the multiplate chamber. It is expected that this device may have a lot of applications .