The contention-based multi access schemes of wireless networks impose difficulties in achieving predictable service quality, especially in multi-hop deployments. In order to offer advanced network services such as flow admission control, the residual capacity of the wireless links should be accurately estimated. In this report, we discuss two proposals as solutions to this problem. The first proposal developed by SABU is a passive residual capacity estimation algorithm that can be implemented in all Wi-Fi (802.11b/g) based platforms. With this algorithm it is possible to obtain more efficient and reliable admission control and routing decisions in wireless access and mesh networks. The second proposal developed by UBP is an intrusive method, more tuned towards WSNs and MANETs, which require active resource estimation methods. Another improvement by SABU presented here is a novel and practical load-based association scheme for WiFi access networks, so that available bandwidth resources are used optimally, in a more balanced and fair manner.