Envisioning the Next Generation Cellular Client

The cellular revolution has been accompanied by a gradual evolution in functionality. The Motorola handie-talkie introduced in the early 1940‟s was a five pound behemoth that barely worked. Contemporary phones have become ubiquitous devices that are outfitted with camera, video, GPS, internet and e-mail. Fourth generation phones are expected to provide high speed internet access for data as well as multi-media through protocols that subsume existing standards. Beyond this, the capabilities of 4G phones have not been spelled out in detail. In this paper we outline our vision of a feature rich next generation phone that is backed up by an infrastructure of service offerings

PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec

Performance Evaluation of Location Management Protocols for Mobile Ad hoc Networks

Abstract — With the availability of location based services, applications that use locations for optimal performance will require efficient location management algorithms, where user locations are kept track with minimal system overhead. Geography based routing in mobile ad hoc networks is one such application that uses location information of nodes in a network to route data packets. Previous work in this area has shown that the selection of location management protocol is critical to the performance of such routing algorithms. Many location management schemes have been proposed in literature, and in an effort to quantitatively compare the performance of some of these schemes, we carry out extensive simulations to study SLURP, SLALoM and HGRID, three grid based protocols described in literature. Our study is two pronged – to compare the performance of location management with network mobility as well as traffic load, and to evaluate the effect these protocols have on the performance of geographic routing in mobile ad hoc networks. Our results show that the Hierarchical Grid Location Management protocol (HGRID) achieves steady performance for data throughput and delay, and minimally affects the performance of geographic routing

Location management in sparse ad hoc networks

Abstract — Geometric routing using source–destination locations has been suggested as a scalable alternative to conventional routing approaches in mobile ad hoc networks. Prior studies have shown that the location of a destination can be found efficiently in large/dense ad hoc networks using intelligent location management schemes by recruiting nodes in specific unit regions of the terrain as location servers. In this work, we show that certain location management protocols that use a grid based approach suffer from the empty server region problem and that their performance can be seriously degraded with decreasing node density in sparse or irregular ad hoc networks. In order to tackle this problem, we introduce proxy based location management, a novel enhancement that can be used in conjunction with existing location management protocols to operate efficiently in sparse or irregular ad hoc networks. Extensive simulations show that proxy based location management combined with routing on an overlay graph constructed from the unit regions operates more effectively in sparse networks than SLURP/GPSR, an existing location management scheme and a geometric routing protocol that routes packets on a planar graph extracted from the unit disk graph

Sociological orbit aware location approximation and routing in manet

Abstract-In this paper, we introduce a novel concept of integrating &quot;macro-mobility&quot; information obtained from the sociological movement pattern of mobile MANET users into routing. The extraction of this mobility information is based on our observation that the movement of a mobile user exhibits a partially repetitive &quot;orbital&quot; pattern involving a set of &quot;hubs&quot; in practice. This partially deterministic movement pattern is both practical and useful in locating nodes and routing packets to them without the need for constant tracking or flooding. Leveraging on this hub-based orbital pattern, we propose a Sociological Orbit aware Location Approximation and Routing (SOLAR) protocol. Through extensive performance analysis we show that SOLAR significantly outperforms conventional routing protocols like Dynamic Source Routing (DSR) and Location Aided Routing (LAR) in terms of higher data throughput, lower control overhead, and lower end-to-end delay