Kevin Wang

Millimeter Wave Mobile Communications for 5G Cellular: It Will Work!

Recent years have witnessed the emergence of machine-to-machine (M2M) networks as an efficient means for providing automated communications among distributed devices. Automated M2M communications can offset the overhead costs of conventional operations, thus promoting their wider adoption in fixed and mobile platforms equipped with embedded processors and sensors/actuators. In this paper, we survey M2M technologies for applications such as healthcare, energy management and entertainment. In particular, we examine the typical architectures of home M2M networks and discuss the performance tradeoffs in existing designs. Our investigation covers quality of service, energy efficiency and security issues. Moreover, we review existing home networking projects to better understand the real-world applicability of these systems. This survey contributes to better understanding of the challenges in existing M2M networks and further shed new light on future research directions.The global bandwidth shortage facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks. There is, however, little knowledge about cellular mm-wave propagation in densely populated indoor and outdoor environments. Obtaining this information is vital for the design and operation of future fifth generation cellular networks that use the mm-wave spectrum. In this paper, we present the motivation for new mm-wave cellular systems, methodology, and hardware for measurements and offer a variety of measurement results that show 28 and 38 GHz frequencies can be used when employing steerable directional antennas at base stations and mobile devices.

28 GHz propagation measurements for outdoor cellular communications using steerable beam antennas in New York city

The millimeter wave frequency spectrum offers unprecedented bandwidths for future broadband cellular networks. This paper presents the worlds first empirical measurements for 28 GHz outdoor cellular propagation in New York City. Measurements were made in Manhattan for three different base station locations and 75 receiver locations over distances up to 500 meters. A 400 megachip-per-second channel sounder and directional horn antennas were used to measure propagation characteristics for future mm-wave cellular systems in urban environments. This paper presents measured path loss as a function of the transmitter - receiver separation distance, the angular distribution of received power using directional 24.5 dBi antennas, and power delay profiles observed in New York City. The measured data show that a large number of resolvable multipath components exist in both non line of sight and line of sight environments, with observed multipath excess delay spreads (20 dB) as great as 1388.4 ns and 753.5 ns, respectively. The widely diverse spatial channels observed at any particular location suggest that millimeter wave mobile communication systems with electrically steerable antennas could exploit resolvable multipath components to create viable links for cell sizes on the order of 200 m.

28 GHz millimeter wave cellular communication measurements for reflection and penetration loss in and around buildings in New York city

In this paper, we present reflection coefficients and penetration losses for common building materials at 28 GHz for the design and deployment of future millimeter wave mobile communication networks. Reflections from walls and buildings and penetration losses were measured for indoor and outdoor materials, such as tinted glass, clear glass, brick, concrete, and drywall at 28 GHz in New York City. A 400 Mega-chip-per-second sliding correlator channel sounder and 24.5 dBi steerable horn antennas were used to emulate future mobile devices with adaptive antennas that will likely be used in future millimeter wave cellular systems [1]. Measurements in and around buildings show that outdoor building materials are excellent reflectors with the largest measured reflection coefficient of 0.896 for tinted glass as compared to indoor building materials that are less reflective. We also found that penetration loss is dependent not only on the number of obstructions and distance between transmitter and receiver, but also on the surrounding environment. The greatest penetration loss containing three interior walls of an office building was found to be 45.1 dB, with 11.39 m separation between the transmitter and receiver.

28 GHz Angle of Arrival and Angle of Departure Analysis for Outdoor Cellular Communications Using Steerable Beam Antennas in New York City

Propagation measurements at 28 GHz were conducted in outdoor urban environments in New York City using four different transmitter locations and 83 receiver locations with distances of up to 500 m. A 400 mega- chip per second channel sounder with steerable 24.5 dBi horn antennas at the transmitter and receiver was used to measure the angular distributions of received multipath power over a wide range of propagation distances and urban settings. Measurements were also made to study the small-scale fading of closely-spaced power delay profiles recorded at half-wavelength (5.35 mm) increments along a small-scale linear track (10 wavelengths, or 107 mm) at two different receiver locations. Our measurements indicate that power levels for small- scale fading do not significantly fluctuate from the mean power level at a fixed angle of arrival. We propose here a new lobe modeling technique that can be used to create a statistical channel model for lobe path loss and shadow fading, and we provide many model statistics as a function of transmitter- receiver separation distance. Our work shows that New York City is a multipath-rich environment when using highly directional steerable horn antennas, and that an average of 2.5 signal lobes exists at any receiver location, where each lobe has an average total angle spread of 40.3° and an RMS angle spread of 7.8°. This work aims to create a 28 GHz statistical spatial channel model for future 5G cellular networks.

Cochlear implantation in the very young child: Long-term safety and efficacy†‡

Widespread universal newborn hearing screening has led to increased identification of infant hearing loss. Supported by improved diagnostic tools allowing more definitive diagnosis of profound sensorineural hearing loss in young children, cochlear implantation in children <12 months of age is now common. Literature supports short‐term safety and improved auditory outcomes in these young children, however long‐term data is lacking. The study examines issues of long‐term safety and efficacy in cochlear implant patients implanted <1 year of age.

Quality of life outcomes in laryngeal and oropharyngeal cancer patients after chemoradiation

OBJECTIVE: The purpose of this study was to compare quality of life issues in patients with advanced laryngeal versus oropharyngeal cancer after treatment with chemoradiation. DESIGN: A cohort study of 31 patients with laryngeal or oropharyngeal squamous cell carcinoma treated with chemoradiation completed the University of Washington quality of life instrument version 4 (UW-QOL v4). Statistical analysis was performed with Wilcoxon rank sum and chi-square tests. SETTING: Academic tertiary care center. RESULTS: Both groups reported similar impairment in the domains of swallowing, chewing, and taste. Oropharyngeal cancer patients reported significantly worse quality of life in the domain of saliva (P < 0.007). CONCLUSION: Swallowing, chewing, and taste were adversely affected by chemoradiation for both groups. Oropharyngeal patients experienced significantly worse problems with saliva than laryngeal patients. These patients reported high levels of satisfaction with health-related quality of life issues. SIGNIFICANCE: Specific head and neck subsites have different morbidities when treated with primary chemoradiation for advanced tumors.

Flat-panel computed tomography versus multislice computed tomography to evaluate cochlear implant positioning

Abstract Objective To evaluate and compare image quality between flat-panel volumetric computed tomography (fpVCT) and multislice CT (msCT) in temporal bones with cochlear implants (CIs), and to evaluate fpVCT imaging for accuracy in determining CI electrode positioning. Methods Six cadaveric temporal bones were imaged prior to CI using fpVCT. Each bone was implanted with an electrode array and rescanned in order to create radial reformatted images through each electrode contact. Electrode–modiolar interval (EMI) distances were measured. The bones were fixed and cut in order to grossly evaluate for CI intrascalar positioning and insertional trauma. Main outcome measure To compare image quality between fpVCT and msCT in temporal bones with CI, and to evaluate the utility of fpVCT in post-implantation temporal bone analysis. Results The mean EMI distances did not differ significantly between fpVCT and msCT images, while the image quality was significantly better for fpVCT. Furthermore, information about intracochlear trauma and intrascalar electrode array positioning can be ascertained using this radiographic technique. Conclusion fpVCT and msCT do not differ significantly in the evaluation of EMI distances in implanted temporal bones, but the image quality is significantly better using fpVCT. Additionally, useful information regarding intracochlear trauma, electrode depth of insertion, and intrascalar positioning can be gained from fpVCT imaging. Given the ease of use, superior image quality, improved convenience, reduced levels of radiation, and agreement with histology, fpVCT is a valuable option for post-implantation temporal bone imaging.

The diagnostic pathway of oropharyngeal squamous cell carcinoma in a large U.S. healthcare system: Diagnostic Pathway of Oropharyngeal Cancer

To examine the current diagnostic pathway of oropharyngeal squamous cell carcinoma (OPSCC) and identify factors associated with time to diagnosis.

P043: The Platysma Flap for Oral Cavity Reconstruction

2001-2006 and literature review of pharyngoesophageal injuries at a tertiary care center. Radiographic diagnostics and surgical interventions were performed. Subjects included in this study had injuries that were acute, chronic, iatrogenic, or traumatic and subsequently managed with locoregional muscle flaps. A Subjective Dysphagia Index was used to evaluate patient progress. RESULTS: Surgical intervention included the use of both sternocleidomastoid and thyrohyoid muscle flaps in the closure of pharyngoesophageal injuries. Immediate outcomes following intervention yielded return to normal diet and relief of associated symptoms. Radiographic studies conducted in the postoperative period demonstrated successful repair of injuries. Nearly three years later patients remain without symptoms of persistent injury and manifest no progression of dysphagia based on the Subjective Dysphagia Index. CONCLUSIONS: Pharyngoesophageal injuries carry a 20% mortality if they are treated within the first 24 hours and 50% if the treatment is delayed. Pharyngoesophageal injury is an entity with which the general otolaryngologist should be familiar because early diagnosis and treatment can help overcome the high rates of morbidity and mortality associated with delayed and improper treatment. The use of locoregional muscle flaps affords a durable repair for pharyngoesophageal injuries. The presenters provide stepwise logical approaches that will aide the general otolaryngologist in the diagnosis and management of pharyngoesophageal injuries.

Quality of life outcomes in the evaluation of laryngeal cancer treatments

Objectives: To evaluate the quality of life issues of patients with laryngeal cancer after treatment with either chemoradiation or total laryngectomies. Methods: A prospective study of 31 patients with a history of stage III/IV laryngeal squamous cell carcinoma treated primarily with either chemoradiation or by total laryngectomy completed the University of Washington quality of life questionnaire. Patients were identified on a volunteer basis in an academic university head and neck clinic setting. Each patient completed the above questionnaire and statistical significance was assessed by nonparametric 2-tailed test. Results: Questionnaires were completed by all 31 patients, 15 patients who underwent primary chemoradiation and 16 patients who underwent a total laryngectomy followed in most cases by radiation. Problems reported in both treatment groups without significant differences were appearance, activity, recreation, shoulder impingement, moods, anxiety, swallowing, chewing, speech, taste, and general questions. However, there were significant differences between the 2 groups in issues of speech, pain, and saliva. The laryngectomy patients reported greater impairment of speech (P = 0.04), and more pain (P = 0.05), while the chemoradiation patients suffered from decreased saliva (P = 0.08). Conclusions: Most patients with laryngeal cancer, whether treated primarily with chemoradiation or total laryngectomy, reported excellent functional outcomes and health-related quality of life issues. Speech, pain, and saliva were recorded as significant factors affecting their daily quality of life.