Dependability in wireless networks: can we rely on WiFi?

WiFi - short for "wireless fidelity" - is the commercial name for the 802.11 products that have flooded the corporate wireless local area network (WLAN) market and are becoming rapidly ingrained in our daily lives via public hotspots and digital home networks. Authentication and confidentiality are crucial issues for corporate WiFi use, but privacy and availability tend to dominate pervasive usage. However, because a technology's dependability requirements are proportional to its pervasiveness, newer applications mandate a deeper understanding of how much we can rely on WiFi and its security promises. In this article, we present an overview of WiFi vulnerabilities and investigate their proximate and ultimate origins. The intended goal is to provide a foundation to discuss WiFi dependability and its impact on current and future usage scenarios. Although a wireless network's overall security depends on the network stack to the application layer, this article focuses on specific vulnerabilities at the physical (PHY) and data (MAC) layers of 802.11 network

WiFi hot spot superdistribution : a profit scheme for WiFi access distribution

The wide-area deployment of WiFi hot spots challenges IP access providers. While new profit models are sought after by them, profitability as well as logistics for large-scale deployment of 802.11 wireless technology are still to be proven. Expenditure for hardware, locations, maintenance, connectivity, marketing, billing and customer care must be considered. Even for large carriers with infrastructure, the deployment of a large-scale WiFi infrastructure may be risky. This paper proposes a multi-level scheme for hot spot distribution and customer acquisition that reduces financial risk, cost of marketing and cost of maintenance for the large-scale deployment of WiFi hot spots

The Second International m-Libraries Conference

Keren Mills reports on a two-day conference exploring and sharing delivery of services and resources to users 'on the move,' via mobile and hand-held devices, held at UBC in Vancouver, BC, Canada, from 23 - 24 June 2009

WiFi emission-based vs passive radar localization of human targets

In this paper two approaches are considered for human targets localization based on the WiFi signals: the device emission-based localization and the passive radar. Localization performance and characteristics of the two localization techniques are analyzed and compared, aiming at their joint exploitation inside sensor fusion systems. The former combines the Angle of Arrival (AoA) and the Time Difference of Arrival (TDoA) measures of the device transmissions to achieve the target position, while the latter exploits the AoA and the bistatic range measures of the target echoes. The results obtained on experimental data show that the WiFi emission-based strategy is always effective for the positioning of human targets holding a WiFi device, but it has a poor localization accuracy and the number of measured positions largely depends on the device activity. In contrast, the passive radar is only effective for moving targets and has limited spatial resolution but it provides better accuracy performance, thanks to the possibility to integrate a higher number of received signals. These results also demonstrate a significant complementarity of these techniques, through a suitable experimental test, which opens the way to the development of appropriate sensor fusion techniques

HVAC SYSTEM REMOTE MONITORING AND DIAGNOSIS OF REFRIGERANT LINE OBSTRUCTION

A heating, ventilation, and air conditioning (HVAC) system of a building includes a refrigerant loop. A monitoring system for the HVAC system includes a monitoring device installed at the building. The monitoring device is configured to measure a first temperature of refrigerant in a refrigerant line located between a filter - drier of the refrigerant loop and an expansion valve of the refrigerant loop. The monitoring system includes a monitoring server, located remotely from the building. The monitoring server is con figured to receive the first temperature and, in response to the first temperature being less than a threshold, generate a refrigerant line restriction advisory. The monitoring server is configured to, in response to the refrigerant line restriction advisory, selectively generate an alert for transmission to at least one of a customer and an HVAC contractor

Pengaruh Penggunaan Wifi Terhadap Aktifitas Keagamaan Bagi Mahasiswa (Studi Kasus Di Kecamatan Peusangan)

Penelitian ini berjudul “Pengaruh Penggunaan Wifi Terhadap Aktifitas Keagamaan Bagi Mahasiswa (Studi Kasus Di Kecamatan Peusangan)”. Penelitian ini bertujuan untuk melihat Pengaruh Penggunaan Wifi Terhadap Aktifitas Keagamaan Bagi Mahasiswa. Terdapat tiga persoalan yang menjadi fokus kajian dalam penelitian ini, yaitu: 1) Bagaimana peranan wifi dalam menunjang pendidikan, 2) Apa saja pengaruh penggunaan wifi di warkop terhadap aktifitas keagamaan mahasiswa di Kecamatan Peusangan, 3) Bagaimana peluang dan tantangan dalam pengembangan dan peningkatan mutu pendidikan dayah salafi di Aceh. Penggunaan wafi lebih banyak digunakan sebagai sarana hiburan yaitu dengan mengakses facebook dan game-game online. Selama ini para mahasiswa umumnya lebih banyak menghabiskan waktu di warung kopi dengan mengakses internet dari pada belajar atau melakukan kegiatan yang bernilai positif, sehingga akan meninggalkan aktifitas keagamaan. Oleh karena itu, berbagai kondisi yang terjadi selama ini yang diakibatkan oleh penggunaan wifi akan diperoleh jawabannya dengan menggunakan metode penelitian lapangan (field research) dengan pendekatan kualitatif. Maka yang menjadi informan atau subyek dalam penelitian ini adalah Pemilik warkop, mahasiswa, dan tokoh masyarakat setempat. Teknik pengumpulan data yang penulis lakukan adalah dengan pengamatan, wawancara dan studi dokumentasi. Hasil penelitian ini penggunaan wi-fi selain berdampak kepada dunia pendidikan juga berdampak kepada aktifitas keagamaan, para pelajar atau mahasiswa yang terlalu lama menggunakan wi-fi mereka sering meninggalkan shalat dan bahkan pengajian agama yang menjadi bekal aqidah kepadanya. Dalam menyikapi problematika penggunaan wi-fi berlebihan yang dilakukan oleh mahasiswa harus ada gerakan pengawasan dari segenap lapisan masyarakat, tidak cukup hanya kepada petugas penegak hukum, namun masyarakat juga harus sama mengawasi penggunanan Wi-fi gratis, terutama yang ada di tempat tempat umum, seperti warung warung kopi, yang ada dipelosok kota dan gampong

E-learning tools: engaging our students?

Since Generation Z students have grown up around WIFI-laptops, video game, etc. they expect technology to be involved in teaching approaches, however students' perception towards e-learning tools indicate that 80% of students (∼180 students) prefer a face-to-face approach.(undefined