Mobile Intelligence

5.5 CONCLUSIONS AND FUTURE TRENDS

In this chapter, we first gave a review of the current cross-layer design approaches in a wireless environment for performance improvement and then presented a review of recently proposed cooperative caching schemes in a MANET environment for improving data accessibility. After that, we introduced our cluster-based cooperative caching scheme, which fully adopted cross-layer design approach to improve performance and make systems more adaptive. From the above experimental results and other cooperative caching schemes, we can see that cooperative caching is an efficient approach in a MANET environment for reducing data query delay and improving data accessibility, and the employment of cross-layer design approach in a MANET environment makes system more efficient and adaptive. We also presented a prefetching scheme that is integrated into the cooperative caching system to further improving the caching performance. In certain conditions, our prefetching scheme greatly reduces the query delay. However, there are still some challenges.

First of all, although cross-layer design is regarded as an effective way to improve performance in wireless computing environment, Kawadia and Kumar [42] pointed out three problems introduced in using cross-layer design approach. First, due to the great success of strict layered architecture in the Internet, it has become the default network architecture of wireless networks, although cross-layer design is a violation ...