Welcome to this special issue of Wireless Personal Communications. This special issue constitutes a selection of best papers from the 2011 ICUFN (International Conference on Ubiquitous Future Networks) Conference. All these papers have been extended and reviewed again by 3 independent reviewers. ICUFN is an annual international conference (www.icufn. org) co-sponsored by IEEE Communications Society and organized by the KICS (Korean Information & Communications Society). The first paper is entitled “Joint Load Balancing of Radio and Transport Networks in LTE system”. Load Balancing (LB) is an important mechanism often used in the cellular networks to offload the excessive traffic from high-load cells to low-load cells. In this paper, a novel concept of joint LB of transport network (TN) and radio network (RN) is proposed for LTE system based on a network-wide unified utility to capture the QoS of TN and RN. A simple local search algorithm is used for practical application. The proposed mechanism is shown by numerical results on both GBR and non-GBR traffic to have better performance than the conventional RN-only LB solution. The second paper entitled “New QoS Resource Allocation Scheme Using GTS for WPANs” proposes a new GTS allocation scheme named unbalanced GTS allocation, which can improve the bandwidth resource efficiently. The network calculus theory based on the fluid model and greedy algorithm are applied to solve the bandwidth underutilization problem. Compared with the standard GTS allocation scheme, it shows an efficient bandwidth allocation with a QoS-guaranteed model and without breaking the standard protocol. The third paper—“Power Allocation for Two-way relay System Based on Sequential Second Price Auction” proposes a sequential second price auction as a mechanism to