In this letter the development and testing of an open enterprise Wi-Fi solution based on virtual APs, managed by a central WLAN controller is presented. It allows seamless handovers between APs in different channels, maintaining the QoS of real-time services. The potential scalability issues associated to the beacon generation and channel assignment have been addressed. A battery of tests has been run in a real environment, and the results are reported in terms of packet loss and delay.

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It is often said that the Internet is ubiquitous in our daily lives, but this holds true only for those who can easily access it. In fact, billions of people are still digitally-disconnected, as bringing connectivity to certain zones does not make a good business case. The only solution for these unsatisfied potential users is to directly undertake the building of the infrastructure required to obtaining access to the Internet, typically forming groups in order to share the corresponding cost. This article presents a global classification and a summary of the main characteristics of different Alternative Network deployments arisen in the last years with an aim to provide Internet services, in places where mainstream network deployments do not exist or are not adequate solutions. The "Global Access to the Internet for All" Research Group of the Internet Research Task Force, where all authors actively participate, is interested in documenting these emerging deployments. As an outcome of this work, a classification has converged by consensus, where five criteria have been identified and, based on them, four different types of Alternative Networks have been identified and described with real-world examples. Such a classification is useful for a deeper understanding of the common characteristics behind existing and emerging Alternative Networks.

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This paper analyzes and compares two different video conference solutions, widely used in corporate and home environments, with a special focus on the mechanisms used for adapting the traffic to the network status. The results show how these mechanisms are able to provide a good quality in the hostile environment of the public Internet, a best effort network without delay or delivery guarantees. Both solutions are evaluated in a laboratory, where different network impairments (bandwidth limit, delay, and packet loss) are set, in both the uplink and the downlink, and the reaction of the applications is measured. The tests show how these solutions modify their packet size and interpacket time, in order to increase or reduce the sent data. One of the solutions also uses a scalable video codec, able to adapt the traffic to the network status and to the end devices.

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Frame aggregation is widely used in 802.11 WLANs in order to provide a significant throughput improvement. However, the latency increase that comes as a counterpart can reduce the quality experienced by the users of applications with real-time constraints. This letter explores the throughput vs. latency tradeoff in the context of central controlled solutions (e.g. SDWNbased). First, a scenario with a single Access Point is used to illustrate the problem, and to propose two possible solutions. Then, a centralized algorithm that dynamically (de)activates aggregation is tested in a scenario with a number of APs. The results show that aggregation parameters can be tuned in order to keep latency in low levels, with a low throughput penalty.