Synchronicity: Pushing the envelope of fine-grained localization with distributed MIMO

Indoor localization of mobile devices and tags has received much attention recently, with encouraging fine-grained localization results available with enough line-of-sight coverage and enough hardware infrastructure. Synchronicity is a location system that aims to push the envelope of highly-accurate localization systems further in both dimensions, requiring less line-of-sight and less infrastructure. With Distributed MIMO network of wireless LAN access points (APs) as a starting point, we leverage the time synchronization that such a network affords to localize with time-difference-of-arrival information at the APs. We contribute novel super-resolution signal processing algorithms and reflection path elimination schemes, yielding superior results even in non-line-of-sight scenarios (with one to two walls separating client and APs). We implement and briefly evaluate Synchronicity on theWARP hardware radio platform using standard 20 MHz wireless LAN channels

EFFICACY OF ULTRASOUND WITH MAITLAND MOBILIZATION OVER SHORT WAVE DIATHERMY WITH MAITLAND MOBILIZATION IN IMPROVING THE FUNCTIONAL PERFORMANCE OF PATIENTS WITH PERIARTHRITIS SHOULDER

Objective: To investigate the effectiveness of ultrasound with Maitland mobilization over Short wave diathermy with Maitland mobilization in improving the functional performance of patients with Periarthritis of shoulder Design: A simple randomized controlled clinical trail Setting: The study was conducted in the department of physiotherapy in Ganga Hospital Coimbatore (India), Vinayaka Mission Hospital Salem (India). Subjects: 30 patients were selected randomly from the population using simple random sampling procedure (Lottery Method) and were divided into two equal groups. Intervention : The experimental group (n=15) were given Ultrasound with Maitland mobilization with 1 MHz in frequency, continuous mode and 1.5 W/cm 2 of intensity with 5cm 2 sized transducer for 10 minutes of treatment duration .The control group (n=15) were given Short wave diathermy with Maitland mobilization for period of 15 min with contra planar technique. Outcome measures: The functional performance was measured using Shoulder Pain and Disability Index (SPADI) scale. Results: In Group-A (Experimental Group ) and Group-B (Control Group), all data was expressed as mean ± , SD and was statistically analysed using paired 't' test and independent 't' test to determine the statistical difference among the parameters at 0.5% level of significance. Statistical data of SPADI showed that, Group-A is significantly different from Group-B with p<0.05; i.e 95% of significance. Conclusion: The post ultrasound Maitland mobilization is found more effective and beneficial than post SWD Maitland mobilization on shoulder functions in periarthritis. KEYWORDS: Maitland mobilizations, Short wave diathermy, Ultrasound, Periarthritis, Glides. Quick Response cod

The need for cross-layer information in access point selection algorithms

Abstract The low price of commodity wireless LAN cards and access points (APs) has resulted in the rich proliferation of high density WLANs in enterprise, academic environments, and public spaces. In such environments wireless clients have a variety of affiliation options that ultimately determine the quality of service they receive from the network. The state of the art mechanism behind such a decision typically relies on received signal strength, associating clients to that access point (AP) in their neighborhood that features the strongest signal. More intelligent algorithms have been further proposed in the literature. In this work we take a step back and look into the fundamental metrics that determine end user throughput in 802.11 wireless networks. We identify three such metrics pertaining to wireless channel quality, AP capacity in the presence of interference, and client contention. We modify the low level software functionality (firmware and microcode) of a commercial wireless adaptor to measure the necessary quantities. We then test, in a real testbed, the ability of each metric to capture end user throughput through a range of diverse network conditions. Our experimental results indicate that user affiliation decisions should be based on metrics that do not only reflect physical layer performance, or network occupancy, but also concretely capture MAC layer behavior. Based on the acquired insight, we propose a new metric that is shown to be highly accurate across all tested network scenarios

Medium access control for ad hoc networks with switched-beam antennas

M.S

Network Protocols for Ad-Hoc Networks with Smart Antennas

Multi-hop wireless networks or ad-hoc networks face several limiting characteristics that make it difficult to support a multitude of applications. It is in this context that we find smart antennas to find significant applications in these networks, owing to their ability to alleviate most of these limitations. The focus of my research is thus to investigate the use of smart antennas in ad-hoc networks and hence efficiently design network protocols that best leverage their capabilities in communication. There are two parts to the proposed objective of designing efficient network protocols that pertain to the nature of the smart antenna network considered, namely, homogeneous and heterogeneous smart antenna networks. Unlike heterogeneous smart antenna networks, where different devices in the network employ different antenna technologies, homogeneous smart antenna networks consist of devices employing the same antenna technology. Further, in homogeneous smart antenna networks, different antenna technologies operating in different strategies tend to perform the best in different network architectures, conditions and application requirements. This motivates the need for developing a {em unified} framework for designing efficient communication (medium access control and routing) protocols for homogeneous smart antenna networks in general. With the objective of designing such a unified framework, we start by designing efficient MAC and routing protocols for the most sophisticated of the smart antenna technologies, namely multiple-input multiple-output (MIMO) links. The capabilities of MIMO links form a super-set of those possible with other antenna technologies. Hence, the insights gained from the design of communication protocols for MIMO links are then used to develop unified MAC and routing frameworks for smart antennas in general. For heterogeneous smart antenna networks, we develop theoretical performance bounds by studying the impact of increasing degree of heterogeneity on network throughput performance. Given that the antenna technologies are already unified in the network, unified solutions are not required. However, we do develop efficient MAC and routing protocols to best leverage the available heterogeneous capabilities present in the network. We also design efficient cooperation strategies that will further help the communication protocols in exploiting the available heterogeneous capabilities in the network to the best possible extent.Ph.D.Committee Chair: Sivakumar, Raghupathy; Committee Member: Blough. Douglas; Committee Member: Ingram, Mary Ann; Committee Member: Ji, Chuanyi; Committee Member: Pratt, Thoma