Temporal variations of IEEE 802.11b signal strengths in an in-building environment

Recent popularity of the IEEE 802.11b Wireless Local Area Networks (WLANs) in a host of current-day applications has instigated a suite of research challenges. The 802.11b WLANs are highly reliable and wide spread. In this work, we study the temporal characteristics of RSSI in the real-working environment by conducting a controlled set of experiments. Our results indicate that a significant variability in the RSSI can occur over time. Some of this variability in the RSSI may be due to systematic causes while the other component can be expressed as stochastic noise. We present an analysis of both these aspects of RSSI. We treat the moving average of the RSSI as the systematic causes and the noise as the stochastic causes. We give a reasonable estimate for the moving average to compute the noise accurately. We attribute the changes in the environment such as the movement of people and the noise associated with the NIC circuitry and the network access point as causes for this variability. We find that the results of our analysis are of primary importance to active research areas such as location determination of users in a WLAN. The techniques used in some of the RF-based WLAN location determination systems, exploit the characteristics of the RSSI presented in this work to infer the location of a wireless client in a WLAN. Thus our results form the building blocks for other users of the exact characteristics of the RSSI.

“Never Give up:” The Strengths and Strategies Used Among Undocumented College Students From Central America to Access and Persist in U.S. Higher Education

The purpose of this study was to identify the strengths and strategies that undocumented college students from Central America used to access and persist in United States higher education. A multiple-case study design was used to conduct in-depth, semi-structured interviews and document collection from ten persons residing in Illinois, Maryland, Ohio, Texas, and Washington. Yosso’s (2005, 2006) community cultural wealth conceptual framework, an analytical and methodological tool, was used to uncover assets used to navigate the higher education system. The findings revealed that participants activated all forms of capital, with cultural capital being the least activated yet necessary, to access and persist in college. Participants also activated most forms of capital together or consecutively in order to attain financial resources, information and social networks that facilitated college access. Participants successfully persisted because they continued to activate forms of capital, displayed a high sense of agency, and managed to sustain college educational goals despite challenges and other external factors. The relationships among forms of capital and federal, state, and institutional policy contexts, which positively influenced both college access and persistence were not illustrated in Yosso’s (2005, 2006) community cultural wealth framework. Therefore, this study presents a modified community cultural wealth framework, which includes these intersections and contexts. In the spirit of Latina/o critical race theory (LatCrit) and critical race theory (CRT), the participants share with other undocumented students suggestions on how to succeed in college. This study can contribute to the growing research of undocumented college students, and develop higher education policy and practice that intentionally consider undocumented college students’ strengths to successfully navigate the institution.