We consider the problem of bulk data transfers and bandwidth sharing in the context of grid infrastructures. Grid computing empowers high-performance computing in a large-scale distributed environment. Network bandwidth, which makes the expensive computational and storage resources work in concert, plays an active role on carrying grid applications traffic. Due to specific traffic patterns and application scenarios, grid network resource management encounters new challenges. From the bandwidth sharing perspective, this article looks at network bandwidth shared among computing and storage elements. Referred to as short-lived, grid data requests with transmission window and volume are scheduled in the network. By manipulating the transmission window, the request accept rate and network resource utilization are to be optimized. The formulated optimization problem is proven NP-complete. Associated with proposed heuristics, simulations are carried out to illustrate the pros and cons of ...