Passing Large dataset through WCF service

Hi frieds, I have created WCF service from where I am returning a dataset having more than 50000 rows and 25 columns. When I request the data from the WCf service it requires about 5000 ms to get the dataset. The time required for to create dataset in service is less than 400 ms. about 4600 ms required to transfer data across WCF service boundry to client application. I am using NetTcpBinding for the WCf service. Anyone has any idea how can I improve the performance of WCF service? Thanks in advance. Regards, Satish Jadhav.