Guest editorial: advances in networking technologies for wireless internet

With the rapid revolution of wireless transmissions technologies, Internet access through wireless mobile terminals has attracted numerous attentions from not only the research community but also industry and end users. In the past 20 years, efforts contributed by fundamental research, industry standardization, and construction of infrastructure have turned the theoretic wireless internet into reality. The major approach of current wireless-internet service provisioning can be usually decomposed by two parts. Specifically, the mobile users often first connect to a telecommunication networks, typically the cellular networks or the Wi-Fi hotspots. Then, the telecommunication networks are responsible for connecting to the internet and fulfilling the data request from mobile users. This approach maximally makes use of the existing infrastructures of both wireless and wired communications networks and has efficiently accommodated current service load of wireless internet connections. However, as the demands on internet connection over wireless networks increase explosively, we face many new challenges in wireless internet service provisioning, which are introduced by the limitation on bandwidth available to internet services, the difficulty in QoS guarantees, the shortage of radio spectrum resources, the heterogeneous networking structures, and so forth. First, telecommunications networks need to accommodate the conventional text, voice call, and video call services between mobile users as well as internet services. The proportion of resources allocated for wireless internet services cannot be arbitrarily high. Second, as aforementioned, the wireless internet services need to handle hybrid wireless and wired connections with different channel features, which make QoS guarantees an unsolved problem. Moreover, the Wi-Fi connections use the industrial, scientific, and medical radio bands, which are shared by many other wireless networks. Thus, the provisioning of wireless internet services over Wi-Fi hotspots suffers from the severe spectrum shortage problem. Last but not the least, although multiple co-existing telecommunications networks bring a better chance for robust internet connection, how to take advantage of the heterogeneous connection resources with well-balanced benefit and costs has not been well addressed nor thoroughly studied. Despite the extensive research work proposed in recent years, the aforementioned issues for wireless internet still remain open problems. This special issue is targeted at addressing the urgent need in the research community as well as the industry to discuss the recent progress and future research directions on wireless Internet. The response to our Call for Papers on this special issue was overwhelming, with over 200 articles submitted from diverse places all over the world. We held a rigorous peer-review process with each paper reviewed by at least experts in corresponding research area, and finally selected nine excellent papers published in this special issue. These nine papers cover a variety of hot topics and cutting-edge technologies in wireless Internet, involving cross-layer design, QoS-provisioning, game-theoretic approach for resource allocation, cognitive femtocell, video quality enhancement over wireless channels, fair scheduling, and so forth. The first paper, Bargaining-based Spectrum Sharing in Cognitive Radio Network [1], contributed by Y. Yan et al. proposes a bilateral bargaining mechanism between two secondary users (SUs) to avoid interference to primary users. The general network scenario with multiple SUs can be decomposed into multiple pairs of bilateral bargaining accordingly. The authors model the bargaining process through dynamic finite/infinite horizon multi-stage games and identify the corresponding equilibria. As a result, spectrum sharing across SUs can be effectively achieved. In the second paper, Queuing Analyses and Statistically-bounded Delay Control for Two-hop Green Wireless Relay Transmissions [2], Q. Du et al. studies the statistically-bounded delay control and green