Stratospheric Communication System Mac Layer Mobile Switching Algorithm

Stratospheric Telecommunication platform communication systems are an important part of the future global communication infrastructures. There is possibility it will become a auxiliary wireless communication system for the mobile communication system on ground and the satellite communication system. One of the main technology need to be resolve is the handover technology, the management of handover will be one of the key factors that influence the system performance. So the article will research the handover method for Stratospheric Telecommunication platform and try to accomplish and improve the performance of the platform on the basis of analysis of the platform's network architecture.First of all, we introduced the original handover method for the platform which already exist and give a detail description to the handover style and handover process.Then, added something which weren't make out but were absolutely necessary like handover decision algorithm, the communication method between BS, the allocation message up grade for MS, the operation after handover failure and the allocation strategy for slots before and after a MS's handover in BS, defined the management messages'formats which were mentioned in the original handover method but weren't defined. All of above is for a complete, scientific handover process.Next, the article analyzed the factors which influenced several main performance indexes like success rate, put forward methods like using reserved bandwidth and choose BS which has light load as the target BS to improve the success rate; using none collision ranging and pre-register method to reduce the handover delay; let serve BS transmit data packet to target BS in order to eliminate the packet loss in the process of handover.After that, this article constructed a system simulation model by OPNET according to frame format and handover method presented before. On the basis of this model, realized the process of a MS handover between different BS, compared the different performance of handover decision algorithms, that is, RSS, RSSH, RSST, RSSHT, and come to the conclusion that RSSHT has the best performance. Then compared the success rate, handover delay, packet loss in the downlink before and after optimization. According to the analysis of the result, we can see the method this article presented can reduce the handover failure rate and the handover delay, and eliminate the packet loss in the downlink, so the performance of the system can be improved.