Increasing HF radio communication capacity to support real time video

This paper proposes an algorithm to increase the performance of high frequency (HF) wireless networks. The solution and results presented in this paper will contribute to achieve a reliable communication system to support real time video packet communications, encoded at about 8 kbps using the H.264 video coding standard. In addition to allowing civil/amateur communications, HF bands are also used for long distance wireless military communications. Therefore, our work is based on NATO Link and Physical layer standards, STANAG 5066 and STANAG 4539, respectively. At each HF channel, a typical transmission bandwidth is about 3 kHz centered at a carrier around 20 MHz with the resulting throughput of up to 12800 bps. This very low bit rate imposes itself serious challenges for reliable and low delay real time multimedia communications. Thus, this paper discusses and presents a solution to increase the performance of real time HF communication systems using channel diversity with a novel and simple combination technique, which is an alternative to soft combining and maximum ratio combining. With our HF channel diversity scheme, the packet loss, on average, is decreased by 15% in comparison to a single channel.