Performance improvements of multiple access modes for tactical data link system

Abstract

Link-16 is an improved data link which is used to exchange tactical information. There are three types of access modes allocating time slots in the Link-16: dedicated access, contention access, and time slot reallocation access mode. Each mode has an inherent problem. This thesis proposes three schemes that overcome the problem of conventional access modes. Two access modes are suggested to enhance the existing contention access mode in link-16, and the other is a totally new access mode based on dynamic resource allocation. The contention access mode in the Link-16 has a possibility of collision. Thus, it is impossible to guarantee the success of transmission. In addition, it can not support Non-Real-Time Variable Bit Rate (nrt-VBR) service. Therefore, we propose two enhanced contention access schemes, namely adaptive power control scheme and channel monitoring scheme. Adaptive power control scheme is that the high priority platform use relatively higher power than the low priority platforms to improve the transmission priority of the high priority platform. Channel monitoring scheme is that platforms which is transmitting the nrt-VBR traffic can utilize the same time slots in the next frame. Adaptive power control scheme is directly applicable to the contention access mode maintaining backward compatibility, and channel monitoring scheme is newly applicable to the contention access mode for supporting the nrt-VBR service in the next generation. Second, we propose a novel access mode for the Link-16. The new dynamic resource access mode can overcome the drawback of the existing access modes, and it can provide variable time slot-on-demand service and priority service in the next generation. Simulations are executed to verify the improvement of enhanced contention access mode and dynamic resource access mode compared with the conventional access modes. Simulation results show that the enhanced contention access mode could improve ...