This report presents improvements of the eXplicit Control Protocol (XCP) in order to support fairness between XCP and TCP flows. Our mechanisms are based on two main components: estimations of the resources needed by XCP, and limitation of the resources taken by TCP. The set of simulations shown in this report proves that we can guarantee a fairness level between XCP and TCP. We think that our TCP-XCP fairness mechanism can be perfectly applied for Long Distance Data Grids, where senders need to transfer large volumes of data.