More and more handsets manufactured today are being equipped with WLAN modules, allowing users to access VoIP service whenever they are within the coverage of WLAN service area. One of the greatest challenges for such dual-mode (say GSM and WiFi) handsets to support ubiquitous communication is the ability to maintain session continuity so a phone call established through one mode can be transfe...

While evolving mobile technologies bring millions of users closer to the vision of information anywhereanytime, device battery depletions still hamper the quality of experience to a great extent. The energy consumption of data transmission is highly dependent on the traffic pattern, and we argue that designing energy efficient data transmissions starts by energy awareness. Our work proposes Ene...

Computer networking often pushes the limit of available bandwidth. Although bandwidth speed has historically increased 10 fold in recent years, reusing existing materials to achieve comparable results to installing new infrastructure is typically preferred. Moreover, the failure of one high speed link results in a significant drop in a network’s instantaneous bandwidth. Bandwidth aggregation al...

We propose WiPLUS – a system that enables WiFi to deal with the stealthy invasion of LTE-U into the frequency bands used by WiFi. Using solely MAC layer information extracted passively, during runtime, out of the hardware registers of the WiFi NIC at the WiFi access point, WiPlus is able to: i) detect interferring LTE-U signals, ii) compute their duty-cycles, and iii) derrive the effective medi...

To construct a WiFi positioning system, dedicated individuals usually gather radio scans with ground truth data. This laborious operation limits the widespread use of WiFi-based locating system. Off-the-shelf smartphones have the capability to scan radio signals from WiFi Access Points (APs). In this paper we propose a scheme to construct a map of WiFi AP positions autonomously without ground t...

In this article we present probabilistic methods to determine the position using the WiFi signal with the use of a classic mobile phone with built-in WiFi. (Probabilistyczne metody określania położenia za pomocą sygnału WiFi). Słowa kluczowe: lokalizacja, wifi, gps, metody probabilistyczne

Sensor networks play an important role to enhance indoor mobile applications. The sensor network for human detection in a house, for example, cooperates with a mobile application and automatically controls home appliances. To realize such enhancement in a vast indoor environment such as in a building, we face a sensor localization problem. We need to get location of huge number of sensor nodes ...

We propose WiPLUS – a system that enables WiFi to deal with the stealthy invasion of LTE-U into the frequency bands used by WiFi. Using solely MAC layer information extracted passively, during runtime, out of the hardware registers of the WiFi NIC at the WiFi access point, WiPLUS is able to: i) detect interfering LTE-U signals, ii) compute their dutycycles, and iii) derive the effective medium ...

The quest for higher data rates in WiFi is leading to the development of standards that make use of wide channels (e.g., 40MHz in 802.11n and 80MHz in 802.11ac). In this paper, we argue against this trend of using wider channels, and instead advocate that radios should communicate over multiple narrow channels for efficient and fair spectrum utilization. We propose WiFi-NC, a novel PHY-MAC desi...

Can WiFi signals be used for sensing purpose? The growing PHY layer capabilities of WiFi has made it possible to reuse WiFi signals for both communication and sensing. Sensing via WiFi would enable remote sensing without wearable sensors, simultaneous perception and data transmission without extra communication infrastructure, and contactless sensing in privacy-preserving mode. Due to the popul...