This paper proposes adaptive transmit window control based on both location of mobile stations and traffic load for channel state based packet transmissions in CDMA cellular downlink communications. The proposed scheme constrains downlink packet transmissions by employing a transmit window individually given to each mobile station. The transmit window size is adjusted by using the optimum threshold value, which is selected with regard to both the mobile locations and the traffic load. The simulation results show that the proposed scheme improved the transmission delay and fairness of service compared with the conventional scheme.

This paper deals with optimizing end-to-end window control algorithms that achieve proportional fairness in the long run, and also investigating their steady state and transient or short-term fairness. An abstracted stochastic model of a bottlenecked connection is employed and the window control is designed to minimize the buffer queue variance while keeping the mean queue level at a target value, taking the round-trip delay into account. An optimal minimum variance window control algorithm and its generalized version are derived with the major aim of reducing the window size fluctuations. A relation between the generalized version and the (p, 1) proportionally fair algorithm is investigated. Also we derive the stability limits of the generalized minimum variance window control algorithm which can be useful during network design. The effects of both the target queue length and a weighting parameter on the steady state and short-term fairness, as measured by Jain's fairness and short-term fairness indices, calculated over short time intervals, are investigated by simulation. The generalized algorithm has better fairness properties as compared to existing algorithms such as that employed in TCP Vegas.

The current congestion control mechanism for TCP with ECN suffers from the oscillation of the window size and the unfair sharing of network resources. These problems are caused by the insufficient information about the congestion level of a network and the different round trip time (RTT) among the connections respectively. In this paper, we propose a new window control algorithm for TCP with ECN to avoid the oscillation of the window size and to achieve the fairness among the connections.

In this paper, we propose the window-based congestion control mechanism using explicit feedback in TCP over ATM ABR service. The proposed scheme is based on notifying the network status as the free buffer length at the congested link to the IP station which informs the window rate by modifying the receivers' advertised window field in TCP ACK returning to the source. Results from simulation show that our proposed algorithm improves the fairness and stability of TCP connections in general network environments even if they have the different round trip times.