Our work reported in this paper attempts to develop a detailed analytical model of the TCP congestion control algorithm in wide-cum-wireless environments with regular TCP traffic that could coexist with other exogenous connections such as voice and video traffic. Thus our model is unlike previous models that did not explicitly consider the impact of non-TCP traffic on the referenced TCP connection. We think that it is extremely difficult and also unnecessary to try to use a single closed-form model to accurately describe the TCP performance. Based on an approximated fluid model, we deduce the TCP throughput performance with arbitrary connection size and the coexistence of non-TCP traffic. Most previous literature on TCP models focused on steady-state TCP congestion control behavior. However, a wealth of evidence suggests that many popular TCP connections are short, often below 30 KB. This paper examines how well our proposed model could capture the behavior of short TCP connections with wireless error losses. The simulation results show that our hybrid method approximates the throughput performance of an arbitrary-sized TCP connection with wireless losses much better than other proposed models. In addition, the throughput performance of multiple TCP connections is analyzed and simulated. Based on our analysis results, we make some suggestions for TCP performance enhancement for overcoming the serious effect from wireless losses.