Personal Communication Services Research Articles

Transparent and conformal wheel-shaped fractal antenna for vehicular communication applications

In this article, a low cost, compact conformal antenna is proposed for vehicular communications applications. The concept of fractal geometry is applied in this design to make the model more attractive in its appearance as well as to attain desired bands in the vehicular communication spectrum. It is fabricated on a transparent and flexible poly vinyl chloride material of size 55 mm × 40 mm × 3 mm. The proposed antenna is intended to operate in GSM-1800/1900, Digital Communication System (DCS-1800), Personal Communication Service (PCS-1900), Universal Mobile Telecommunications System (UMTS), Long-Term Evolution (LTE2600), Industrial, Scientific, and Medical radio band (ISM 2.4G), Wireless local area network (WLAN), Bluetooth, World Interoperability for Microwave Access (WiMAX), IEEE802.11p protocol based Vehicle-to-everything, Dedicated short-range communications (DSRC) and Wireless Access in Vehicular Environments (WAVE) communications bands. The prototype of the antenna in its planar and conformal versions exhibit the wideband characteristics and their measured results show good agreement with that of obtained simulation results. The virtual analysis of platform mounted characteristics of the proposed antenna at two different locations of the vehicle (vehicle roof-top and on side-view mirror) are performed in ANSYS Savant simulation tool and the corresponding far-field radiation performance is characterized.

Combination of MIMO Antennas for Handheld Devices [Wireless Corner

With the development of the fourth-generation (4G) and fifth-generation (5G) wireless systems and the high-data transmission rate requirements, multiple-input, multiple-output (MIMO) antennas are becoming necessary in mobile terminals. Handheld mobile devices support various service standards, such as Wi-Fi, LTE, Wi-Max, personal communications service, and digital cellular systems.

Dual‐band meander‐line MIMO antenna with high diversity for LTE/UMTS router

A dual-band multiple-input multiple-output (MIMO) antenna is presented. The proposed MIMO antenna consists of two elements of meander-line antenna with an isolation improvement structure located between the two radiating antenna elements. The antennas operate in the 4G long-term evolution (LTE) (699-798 MHz) band, and Universal Mobile Telecommunications Service (UMTS) (Digital Cellular System (DCS)/Personal Communications Service (PCS)) bands (1920-2170 MHz) with | S 11 | = -6 dB (voltage standing wave ratio (VSWR) = 3) matching criteria. The measured mutual coupling is lower than -15 and -22 dB at the LTE 700 bands, and UMTS bands, respectively. The diversity performance of the envelope correlation coefficient and the mean effective gain meets the diversity criteria for mobile communications. Total radiation efficiencies range between 60 and 90% over the operating frequency bands. A prototype antenna was fabricated and tested for design verification. The simulated results are in good agreement with the measurements.

An investigation on metaheuristic techniques for solving cell to switch assignment problem

The assignment of cells to switches in a Personal Communication Services Network (PCSN) is a Non-Deterministic Polynomial Time (NP) hard problem with exponential complexity and is among the hardest combinatorial optimisation problems of great practical importance in wireless communication systems. The objective is to assign cells to switches in an optimal manner, such that the cost comprising the sum of hand-off, cabling and switching cost is minimised with reasonable accuracy in an acceptable time scale, while obeying the constraints that each cell must be assigned to exactly one switch and total load of all the cells which are assigned to a switch is below the capacity of the switch. The aim of this article is to experimentally investigate the performance of three recent metaheuristic algorithms namely Bat Algorithm (BA), Firefly Algorithm (FA) and Flower Pollination Algorithm (FPA) for solving the Cell to Switch Assignment (CSA) problem.

Ant colony prediction by using sectorized diurnal mobility model for handover management in PCS networks

Recently, mobile phones are extremely used in lifestyle. Historical records of mobile users (MUs) play an important role in predicting future movements of new visitors of the underlying registration area. Handover (handoff) is one of important quality of service (QoS) parameter that affects the continuity of the call when MUs move from a cell to its neighbors in the same registration area (RA). In this paper, a novel ant based Algorithm, has been introduced, which is called Ant Prediction Algorithm (APA). The main target of APA is to reduce handover impact on the performance of personal communication service (PCS) networks. To accomplish such aim, APA tries to minimize the number of dropped calls by predicting the long-term movement of MUs based on the Sectored Diurnal Mobility Model (SDMM). APA consists of two Parts, namely; (i) the Ant Prediction Engine (APE), which relies on the movement history of the other MUs to predict the future movement of the considered MU, and (ii) the SDMM design, which predicts the exact future sector and cell of the considered MU. Simulations have been presented to validate the proposed scheme in terms of prediction accuracy and handoff blocking probability.

Dual-Band Half-Elliptic Hoof Antenna With Mathieu Function for a Femto-Cell Network

The design of a half-elliptic hoof antenna for a femto-cell network in a multi-input multioutput system is proposed. The proposed half-elliptic hoof antenna incorporates half-elliptic surfaces, and has multiresonance frequencies in its TM modes. The half-elliptic design of the proposed antenna resonates with two main current paths, and the resonant frequency of each mode can be calculated using the Mathieu function. Moreover, an additional resonator is inserted between the half-elliptic patch and a ground to obtain additional resonance frequency and a wider bandwidth on the high band. The proposed antenna covers the frequency bands from 880 to 960 MHz and from 1710 to 2170 MHz for Global System for Mobile Communications (GSM)/Digital Cellular System (DCS)/Personal Communications Service (PCS)/International Mobile Telecommunications (IMT) with a peak gain of 6.8 dBi. To validate the design of the proposed antenna, the analysis of the antenna using the simulated and measured results is presented and discussed.

The media go-along: Researching mobilities with media at hand

This article contributes methodologically and theoretically to Christine Hine’s call for a mobilities oriented internet ethnography. First, a ‘media go-along’, combining interviews and observations of a personal communication service at hand, is developed. Research participants give verbal and visual tours, framed by the researcher’s discursively constituted invitations for orientation. Then, a theoretical framework integrating an analysis of media environment mobilities is developed. From research material on hook-up and dating apps targeting non-heterosexual men, it is shown how 1) research participants’ navigation is materially contingent upon the medium and subject to momentary purposes and styles, 2) researcher presence and access must regularly be re-inscribed discursively, and 3) mobile media analysis, based on the media go-along’s representations of verbal, material, affective, and kinetic aspects of social interaction, is useful in the analysis of socially-conditioned access to, and production of, single media practice and experience.

Numerical dosimetry of CDMA/GSM, DCS/PCS and 3G signal jammers

In this study, numerical dosimetry of a code division multiple access (CDMA)/global system of mobile, digital cellular service (DCS)/personal communications service (PCS) and third generation signal jammer working with three antennas is presented. Three anatomical full human body models of different ages and gender exposed to the signal jammer electromagnetic (EM) waves at 900, 1800 and 2100 MHz, simultaneously, are numerically modelled using a high-resolution finite-difference time-domain gridding; solved by a full-wave three-dimensional EM simulation software on a high-performance workstation machine. The average specific absorption rate (SAR) in the whole human body and the peak spatial SAR averaged over 1 g induced in the head and torso biological tissues were evaluated at different distances from the signal jammer above a ground consisting of concrete and soil layers. The maximum radiated power by the signal jammer at different distances against the human body was calculated for the safe exposure in compliance with the Institute of Electrical and Electronics Engineers (IEEE)/American National Standards Institute (ANSI)/Federal Communications Commission (FCC) standard limits.

Historical based location management strategies for PCS networks

Due to the current popularity of wireless communication, personal communication service networks have attracted a lot of attention. As mobile terminals (MTs) in such networks have the ability to communicate on the move, location management (LM) is a critical issue that should be handled carefully. Managing MTs locations is to simultaneously perform two main operations, which are; location update and paging. A good LM strategy maintains both operations with the minimum time and signaling penalties. Although several LM strategies have been introduced, they still suffer from several drawbacks. This paper introduces three novel LM strategies, which are; historical based location management (HBLM), direction based location management (DBLM) and trajectory based location management (TBLM). TBLM strategy is based on geographical position of MTs, while HBLM and DBLM are based on geographical position of MTs as well as time aspects. Visited locations are saved in MT's internal cache in the form of cell identifier as well as the corresponding time interval. Location tracking is fully supervised by the MT's current visitor location register (VLR). On the other hand, the collected location information in MT's cache is sent to VLR when MT passed through a previously defined number of cells or when a previously defined number of time periods has elapsed. In HBLM, paging is done according to the historical movements saved in VLR, while DBLM takes also MT's movement direction into consideration while in TBLM, paging is done according to the historical trajectories that MTs are used to follow. Experimental results have shown that the proposed LM strategies significantly improve MTs' tracking process as they introduce the minimum signaling penalty (for paging and registration) with an acceptable paging time delay compared with recent LM strategies.

Design of a Compact Quad-Band Slot Antenna for Integrated Mobile Devices

In order to incorporate different communication standards into a single device, a compact quad-band slot antenna is proposed in this paper. The proposed antenna is composed of a dielectric substrate, T-shaped microstrip patch with a circle slot and an inverted L-slot, and a comb-shaped ground on the back of the substrate. By adopting these structures, it can produce four different bands, while maintaining a small size and a simple structure. Furthermore, a prototype of the quad-band antenna is designed and fabricated. The simulated and measured results show that the proposed antenna can operate over the 1.79–2.63 GHz, 3.46–3.97 GHz, 4.92–5.85 GHz, and 7.87–8.40 GHz, which can cover entire PCS (Personal Communications Service, 1.85–1.99 GHz), UMTS (Universal Mobile Telecommunications System, 1.92–2.17 GHz), WCDMA (wideband code-division multiple access, 2.1 GHz), Bluetooth (2.4–2.48 GHz), WiBro (Wireless Broad band access service, 2.3–3.39 GHz), WLAN (Wireless Local Area Networks, 2.4/5.2/5.8 GHz), WiMAX (Worldwide Interoperability for Microwave Access, 2.5/3.5/5.5 GHz), and X-band SATcom applications (7.9~8.4 GHz). The proposed antenna is particularly attractive for mobile devices integrating multiple communication systems.

Low specific absorption rate microstrip patch antenna for cellular phone applications

The aim of this study is to design a new microstrip-fed patch antenna for cell phone applications. The antenna design is composed of slots and Flame Retardant 4 dielectric substrate fed by a partial ground plane and a microstrip line. The user's effects on antenna performances are also analysed using standard specific anthropomorphic mannequin head phantom. The specific absorption rate (SAR) values of the proposed antenna are evaluated for different frequency bands considering cheek position of talk mode. The proposed antenna has an impedance bandwidth of 230.4 MHz (0.725-0.95 GHz, lower band), and 522.24 MHz (1.74-2.25 GHz, upper band), which can cover global system for mobile (GSM) 900 MHz, digital communication system 1800 MHz, personal communications service 1900 MHz, GSM 1900 MHz, and universal mobile telecommunications service 2100 MHz bands. Moreover, the proposed antenna produces lower SAR values in the human head than that of a dipole antenna, helical antenna, and planar inverted-F antenna.

Triple-notch UWB monopole antenna with fractal Koch and T-shaped stub

In this study, a triple-notch ultra-wideband (UWB) monopole antenna with fractal Koch and T-shaped stub is presented. The prototype antenna is based on a circular monopole antenna with a back-plane feed line modified for 2–11GHz in an omnidirectional pattern. By implementing a combination of fractal Koch and T-shaped stub on the antenna, a triple-notch band occurred at 2, 3.5, and 5.8GHz for rejecting personal communication services (PCS), worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN). In addition to the UWB application frequency range of 3.1–10.6GHz, the final antenna covers a frequency range of 1.78–1.91GHz for GSM 1800, 2.28–3.120GHz for Wi-Fi, and 2.4GHz for Bluetooth applications with a voltage standing wave ratio (VSWR)<2. Simulated results of HFSS and CST are compared with experimental results. The dimensions of the antenna are 50mm×50mm×1.6mm. The current distribution and efficiency at notch frequency are noted for the whole frequency band, and the maximum antenna gain is between −3.5 and 6.5dBi. In this study, methods using Koch structure and T-shaped stub to achieve triple-notch antenna are implemented in three steps. In addition, the effects of T-shaped stub and fractal Koch on the magnitude of the antenna (S11) are studied.

Retraction Note to: New probabilistic models for managing user’s locations in PCS networks

Personal communication service (PCS) networks enable mobile terminals (MTs) to communicate regardless of their locations. However, in order to guarantee an efficient service delivery, MTs' real time locations should be perfectly managed. Location management (LM) includes two fundamental processes; registration and paging. The former is concerned with the reporting of the current locations of the MTs, while the latter is used to locate a MT. Both processes incur signaling cost across the wireless channel. The more the location updates, the less the paging signaling cost, thus there is a tradeoff in terms of signaling cost. Due to the scarcity of PCS wireless bandwidth, it is important to reduce that signaling cost. As The blanket paging in current mobile networks wastes a lot of wireless bandwidth, we focus on the subject of paging and try to reduce the paging signaling cost under a predefined delay bound. Our contribution can be summarized as: (i) establishing a family of probability based paging strategies; (ii) introducing a novel topology for PCS registration area, which is called the hot spot topology (HST); (iii) based on HST, a novel LM strategy, which is called Flower Based Strategy had been introduced. Experimental results had shown that that the proposed paging strategies substantially lower the signaling cost of paging compared to the blanket one with a negligible increase in paging delay.

Design of broadband dual-polarized antenna with integrated Marchand balun

A design of broadband dual-polarized antenna with low cross polarization and high isolation was presented. The antenna is composed of a cross dipole, a folded ground, two feeding networks, and a reflector. The impedance bandwidth was enhanced by utilizing the mutual coupling between the two dipoles. A kind of meandering folded Marchand balun was skillfully integrated on the support column of the antenna to excite the dipole differentially, which can deliver both balanced (within 0.5 dB) power splitting and consistent (±5°) phase shifting from 1.71 GHz to 2.17 GHz. The standing wave ratios (SWRs) of each port are less than 1.5. By using this feeding network, the antenna has good performance in isolation (> 45 dB) and cross polarization (> 30 dB) over the entire operating frequency band. Moreover, the gain (∼8.6 dB) of the proposed antenna is stable with frequency and the antenna structure is very firm due to the support column. The proposed antenna can be easily formed an array for digital cellular system (DCS), personal communications service (PCS) and 3rd generation (3G) applications.

Performance analysis of multihop communication using generalized gamma fading model

Due to ubiquitous access of personal communication services multiple communication through multihops are needed for exchange of data between source and destination across the wireless network. Recently cascade fading models have gained significance as they can model multihop relay fading channels. Generalized Gamma (GG) model being a versatile, flexible and multiparameter model has been selected here as it can generalizes commonly used fading models such as Weibull, Nakagami-m etc. Exact closed expressions of Probability Density Function (PDF) and Cumulative Distribution Function (CDF) are obtained here for the product of multiple GG random variables (RVs). Based on the derived expressions performance analysis of multihop links has been done here in terms of coefficient of variation (CV), amount of fading (AF) and Spectral efficiency and outage probability. Despite of the exact form, the expressions obtained here are in closed form, tractable and easy to evaluate.

Power Consumption Optimization of Location Management in PCS Network

In this paper, we develop an approach to optimize power consumption using solar energy and also develop an approach for storing power as backup power resource. The following aspects of this paper are 1) location management based on location update (LU) and paging method by considering the location area (LA) architecture in personal communication service (PCS) networks. 2) Try to reduce location management cost by utilizing global natural solar energy resource by solar energy harvester and 3) create a backup storage for solar energy during day—off situation.

A Hybrid Mobility Prediction (HMP) strategy for PCS networks

Recently, several high-speed applications have been emerged for personal communication service (PCS) networks. Therefore, locating mobile terminals (MTs) as they move from one place to another is the key to provide continuous services with unrestricted mobility. To maintain the continuity of service during handoffs, PCS involves the need to predict MTs' movements to cope with resource limitations and heterogeneity. Predicting MT's next location in PCS networks has become an inherently interesting and challenging problem. If we can correctly predict the next cell to which MTs are going, the performance of wireless applications, such as call admission control, QoS, and mobility management can be improved as well. Mobility prediction based on MTs' movement history has become an effective mean not only to decrease call-dropping probability, but also to shorten the handover latency. However, applying various basic prediction schemes to realistic environments has reported several limitations. Moreover, the randomness of MT's motion prevents the accurate prediction. In this paper, a Hybrid Mobility Prediction (HMP) strategy has been proposed. HMP provides flexible usage of the limited resources of PCS networks. It combines evidence from three different predictors, which are; probabilistic predictor (PP), group-based predictor (GP), and spatial predictor (SP). PP relies on Bayes theorem, GP uses ant colony optimization (ACO), while SP tries to detect the topological architecture of the current registration area to enhance the prediction process. HMP provides high accurate prediction of the next cell to which an MT is going, which avoids over reservation resulting in a waste of resources. Experimental results have shown that HMP outperforms recent prediction strategies as the amount of reserved resources is dynamically adjusted based on the predicted cell.

Trademark Disparagement &amp; Advertising Ethos-Pathos: India

This Research Paper deals with following questions of intrinsic importance qua 'trademark disparagement':1. What is 'trademark disparagement'? What acts qua trade-rivals constitute 'trademark disparagement'? 2. What is 'comparative advertising'? Can 'comparative advertising' constitute 'trademark disparagement'? Author asserts that laws qua 'comparative advertising' in India owe their existence to the following case-laws of the U.K.- a. Cable & Wireless Plc v. British Telecommunications, 1998 FSR 383 b. Barclays Bank Plc v. RBS Advanta, 1996 RPC 307, Chancery Division c. Vodafone Group Plc v. Orange Personal Communications Services Limited, 1997 FSR 34 d. British Airways Plc v. Ryanair Ltd., 2001 FSR 32To see how laws qua 'comparative advertising' are positioned in India, author compares laws prevailing in the Indian jurisdiction with laws prevailing as such in U.K. and U.S.3. What is 'generic disparagement'? Does 'generic disparagement' constitutes 'trademark disparagement'? If yes, in what cases?4. What is the difference between "Puffing" and "Trademark Disparagement"?5. What is the difference between "Passing Off" and "Trademark Disparagement"?6. What are the different tests qua ‘trademark disparagement’? How is the 'single meaning rule' different from the 'multiple meaning rule'?7. How adjudication qua ‘trademark disparagement’ has taken place in India in the light of the following case-laws:I. Reckitt & Colman of India Ltd. v. M.P. Ramachandran & Ors., 1999 PTC (19) 741II. Pepsi Co. Inc. v. Hindustan Coca-Cola Ltd., 2003 (27) PTC 305 (Del) (DB)III. Dabur India Ltd. v. Colgate Palmolive India Ltd., 2004 (29) PTC 401 (Del)IV. Karamchand Appliances (P) Ltd. v. Sh. Adhikari Brothers, 2005 (31) PTC 1 (Del)V. Dabur India Ltd. v. Wipro Limited, 2006 (32) PTC 677 (Del)VI. Unibic Biscuits India (P) Ltd. v. Britannia Industries Ltd., MANU/KA/0240/2008VII. Dabur India Ltd. v. Colortek Meghalaya (P) Ltd., (2010) 44 PTC 254 (Del) (DB)VIII. Hindustan Unilever Limited v. Cavincare Private Ltd., 2010 (44) PTC 270 (Del)

Advanced Antenna Technologies for Satellite Communications Payloads

A review of various antenna technologies suitable for satellite communications and applicable to fixed satellite, broadcast satellite, mobile communications, and personal communications services is presented. Antenna technologies suitable for generating contoured beam and multiple-beam antennas are reviewed. Design considerations for reflector antennas and feed assemblies and antenna performance in terms of coverage gain, sidelobe isolation, and cross-polar isolation are discussed. Current and future technological trends are presented in the above areas.

Nutritional Intake and Poverty in Mexico: 1984-2010

Using nutritional information of food items acquired by each household, we evaluate how Mexico’s nutritional (calorie and protein-based) poverty has changed over time. Our extensive dataset combines household surveys from 1984, 1989, 1992, 1996, 2000, 2004, 2006, 2008 and 2010. We find per capita calorie intake has decreased over time for both urban and rural households. The pattern is similar to the case of India, where a decline in calorie intake between 1983 and 2005 has been documented (Deaton & Dreze, 2009). In both urban and rural areas, nutritional poverty is increasing over time. For instance, the estimate of urban households who did not have an adequate calorie intake increased from 46% in 1984 to 64% in 2010. Unlike the case of India (Gaiha, Jha and Kulkarni, 2010), we find strong declines in calorie intake for the bottom expenditure quartile of the population, where calorie poverty in urban areas increased from 69% in 1984 to 95% in 2010. We find that increased prices of nutrients can only partly explain the calorie and protein intake drop. The decrease in intake can also be explained as consumers have shifted consumption away from food items and into other goods, such as personal care, communication, and vehicle services. Still, some of the drop in nutrient intake remains unexplained, especially for urban poor households. Our results also indicate that even though there is a decrease in per capita household calorie intake, children are obtaining a greater share of total household calories over time.