Data Distribution Management (DDM) is one of the six services provided by HLA/RTI as complementarities of Declaration/Interests Management to provide a flexible and extensive mechanism for further throttling the data placed on the network and delivered to federates based on simulated entities' interests of data. DDM is of essential importance especially for large scale distributed simulations. In the past a few years, two main types of DDM protocols have been developed, named region-based methods and grid-based methods. However, all of these techniques have their obvious drawbacks, which affect their deployment in most applications that require high performance and low overhead. In our previous work, we have proposed a dynamic grid-based DDM scheme that shows a great potential when compared to both region-based and grid-based approaches. In this paper, we wish to improve our previous scheme, which we refer to as optimized dynamic grid-based DDM, to further reduce irrelevant data that might be received by simulated entites.