Mobile phone

Smart phones have become a powerful platform for wearable context recognition. We present a service-based recognition architecture which creates an evolving classification system using feedback from the user community. The approach utilizes classifiers based on fuzzy inference systems which use live annotation to personalize the classifier instance on the device. Our recognition system is designed for everyday use: it allows flexible placement of the device (no assumed or fixed position), requires only minimal personalization effort from the user (1-3 minutes per activity) and is capable of detecting a high number of activities. The components of the service are shown in an evaluation scenario, in which recognition rates up to 97% can be achieved for ten activity classes.

Mobile marketing is set to make a big impact in Australia. However, experience from the use of email for marketing purposes demonstrates that there are a number of pitfalls that companies can fall into and which consumers react badly to. The paper examines various theoretical approaches that can be used to investigate effective m-marketing strategies. We use an adapted version of the unified view of user acceptance of IT to determine the factors that impact on the intention to participate in m-marketing. A survey of mobile phone users shows that consumers view the benefits of m-marketing as saving money, saving time and providing useful information. Consumers think that granting permission is an important factor in a decision to participate in mmarketing. In addition, financial incentives can substantially improve the level of participation. It would appear that the effort and time involved in processing m-marketing messages are not important factors in the decision to participate in m-marketing schemes.

This paper presents the socio-economic profile of households in the Family Dynamics Study (FDS) (1997-2001) and makes comparisons with the earlier Functional Groups Study (FGS) (1992-1996). For the current study, FGS villages with a high prevalence of child malnutrition were purposively selected. In each village selected, all households were included, and interviews with a structured questionnaire were conducted in April-May 1998. Incomes were generally low and incidence of poverty was high; 49.6% of the households were under the poverty line income, of which 37.2% were poor and 12.4% were hard core poor. Overall, only 23.2% of heads of households were in agricultural occupations, others being primarily waged workers and petty traders. Livestock rearing was widespread (57.8%), and most households (90.4%) owned at least one motorised vehicle, the most common being the motorcycle. The majority of households had refrigerators (73.6%), washing machines (58.8%), and televisions (91.1%); ...

Telecommunication and more specially mobile phones have the potential to provide solution to the existing information asymmetry in various lagging sectors like Agriculture. India’s agricultural sector suffers from low growth rates and low productivity. Issues in access to information is a week point at every stage of the agrisupply chain. For small farmers base economy like India, access to information can possible enable better incomes and productivity to the farmers. This paper through focus group discussions and in-depth interview with farmers in villages of India, has tried to find answers to the use and impact of mobile and mobile enabled services on agricultural productivity. The answers to these questions are of relevance to develop better policy environment conducive for the small and medium farmers and has implications for mobile operators, for information service providers, and for policy-makers. The results show that although, mobiles can act as catalyst to improving prod...

This paper presents an application, "LentInfo", which is a system used to provide information about programmes for the Festival Lent in Slovenia. The Festival Lent consists of different open-air theatre and music performances and raws more than 400,000 visitors per year. This application is based on a Hidden Markov Model (HMM) speech recogniser, and the dialogue construction and management is done using the CSDP (Common Spoken Dialogue Platform) dialogue management system. It is represented as a finite-state structure. The dialogue can be specified in a script using simple syntax description. The dialogue manager is multi-application oriented, so it can easily be upgraded for new applications. If some new concepts are needed, only new actions need be added to the existing ones. Currently, prompt messages are prerecorded, but it is also possible to include a speech synthesis system depending on the needs of the application. Error recovery during the dialogue is done with user confirmation of the recognised input speech. The results are presented for tests performed in the year 2001. The results are analyzed according to the phone type (fixed/mobile), signal to noise ratio, dialogue path, etc. Although some calls where carried out using mobile phones from noisy festival places, the performance of the system decreased only slightly under these conditions.

Around the globe, various initiatives use the mobile phone to provide financial services to those without access to traditional banks. Yet relatively little scholarly research explores the use of these m-banking/m-payments systems. This paper calls attention to this gap in the research literature, emphasizing the need for research focusing on the context(s) of m-banking/mpayments use. Presenting illustrative data from exploratory work with small enterprises in urban India, it argues that contextual research is a critical input to effective "adoption" or "impact" research. Further, it suggests that the challenges of linking studies of use to those of adoption and impact reflect established dynamics within the Information and Communication Technologies and Development (ICTD) research community. The paper identifies three crosscutting themes from the broader literature-amplification vs. change, simultaneous causality, and a multidimensional definition of trust-each of which can offer increased theoretical clarity to future research on m-banking/m-payments systems. Notes on contributors Jonathan Donner is a researcher in the Technology for Emerging Markets Group at Microsoft Research, where he studies the social and economic impacts of mobile communication technologies in developing countries. Camilo Tellez is a doctoral student in the department of Information Systems at the London School of Economics and Political Science, where he specializes in IT for development issues. m-banking Pre-publication draft. Edits possible.

Computer vision applications for mobile phones are gaining increasing attention due to several practical needs resulting from the popularity of digital cameras in today's mobile phones. In this work, we consider the task of face detection and authentication in mobile phones and experimentally analyze a face authentication scheme using Haar-like features with Ad-aBoost for face and eye detection, and Local Binary Pattern (LBP) approach for face authentication. For comparison, another approach to face detection using skin color for fast processing is also considered and implemented. Despite the limited CPU and memory capabilities of today's mobile phones, our experimental results show good face detection performance and average authentication rates of 82% for small-sized faces (40×40 pixels) and 96% for faces of 80×80 pixels. The system is running at 2 frames per second for images of 320×240 pixels. The obtained results are very promising and assess the feasibility of face authentication in mobile phones. Directions for further enhancing the performance of the system are also discussed.

In this paper, we propose a framework for content collection and connection enabled by public large screens and mobile phones. Making people express their stories will encourage their active attitudes toward information management. With the proposed framework, we aim to overcome difficulties on managing flooding information. We applied the framework on two practice oriented systems and held workshops using them.

A lot has been done in the use of Information and Communication Technology (ICT) in business yet very little in solving agricultural problems in developing countries. The problem addressed in this paper is the integration of widely available knowledge, processing and providing effective delivery for countries with low ICT infrastructure. Data was collected from small-scale farmers, meteorologists, agricultural extension officers and a research station and analyzed. From this, a suitable knowledge based model was developed. In order to evaluate the model, a prototype was developed and used in tests with sample data. The results reveal that the best way of disseminating agro-meteorological information to small scale farmers is using an integrated knowledge management system and mobile phone technology.

At work and at leisure people perform various visual search tasks, e.g. they search for a particular icon in software tools, on Web sites or on mobile phones. With an increasing number of items, visual search becomes difficult. Recently, it has been suggested that the so-called contextual cueing effect, which is known from psychological experiments, can be applied to improve visual search performance. Contextual cueing leads to decreased search times for target objects within familiar context configurations. It is assumed that associations between context configurations and target locations are learned implicitly and then used to guide the allocation of attention to the relevant object. In accordance with demands for interface consistency, this mechanism could be interesting for the development of user interfaces. The present study investigated which object features (e.g. color or orientation) can establish the learning process. The results show that implicit learning of color and orientation arrangements are possible, but the transfer to configuration with changed features depends on the recent learning history. Implications of these results are discussed with respect to the design of user interfaces.

The growing need of the driving public for accurate traffic information has spurred the deployment of large scale dedicated monitoring infrastructure systems, which mainly consist in the use of inductive loop detectors and video cameras. On-board electronic devices have been proposed as an alternative traffic sensing infrastructure, as they usually provide a cost-effective way to collect traffic data, leveraging existing communication infrastructure such as the cellular phone network. A traffic monitoring system based on GPS-enabled smartphones exploits the extensive coverage provided by the cellular network, the high accuracy in position and velocity measurements provided by GPS devices, and the existing infrastructure of the communication network. This article presents a field experiment nicknamed Mobile Century, which was conceived as a proof of concept of such a system. Mobile Century included 100 vehicles carrying a GPS-enabled Nokia N95 phone driving loops on a 10-mile stretch of I-880 near Union City, California, for 8 hours. Data were collected using virtual trip lines, which are geographical markers stored in the handset that probabilistically trigger position and speed updates when the handset crosses them. The proposed prototype system provided sufficient data for traffic monitoring purposes while managing the privacy of participants. The data obtained in the experiment were processed in real-time and successfully broadcast on the internet, demonstrating the feasibility of the proposed system for real-time traffic monitoring. Results suggest that a 2-3% penetration of cell phones in the driver population is enough to provide accurate measurements of the velocity of the traffic flow.

A variety of cutting edge applications for mobile phones exploit the availability of phone sensors to accurately infer the user activity and location to offer more effective services. To validate and evaluate these new applications, appropriate and extensive datasets are needed: in particular, large sets of traces of sensor data (accelerometer, GPS, micro-phone, etc.), labelled with corresponding user activities. So far, such traces have only been collected in short-lived, smallscale setups. The primary reason for this is the difficulty in establishing accurate ground truth information outside the laboratory. Here, we present our vision of a system for largescale sensor data capturing, leveraging all sensors of todays smart phones, with the aim of generating a large dataset that is augmented with appropriate ground-truth information. The primary challenges that we address consider the energy cost on the mobile device and the incentives for users to keep running the system on their device for longer. We argue for leveraging the concept of the checkin -as successfully introduced in online social networks (e.g. Foursquare) -for collecting activity and context related datasets. With a checkin, a user deliberately provides a small piece of data about their behaviour while enabling the system to adjust sensing and data collection around important activities.

Rising concern over the poor level of blood-pressure (BP) control among hypertensive patients has prompted searches for novel ways of managing hypertension. The objectives of this study were to develop and pilot-test a home BP tele-management system that actively engages patients in the process of care.Phase 1 involved a series of focus-group meetings with patients and primary care providers to guide the system’s development. In Phase 2, 33 diabetic patients with uncontrolled ambulatory hypertension were enrolled in a 4-month pilot study, using a before-and-after design to assess its effectiveness in lowering BP, its acceptability to users, and the reliability of home BP measurements.The system, developed using commodity hardware, comprised a Bluetooth-enabled home BP monitor, a mobile phone to receive and transmit data, a central server for data processing, a fax-back system to send physicians’ reports, and a BP alerting system. In the pilot study, 24-h ambulatory BP fell by 11/5 (±13/7 SD) mm Hg (both P < .001), and BP control improved significantly. Substantially more home readings were received by the server than expected, based on the preset monitoring schedule. Of 42 BP alerts sent to patients, almost half (n = 20) were due to low BP. Physicians received no critical BP alerts. Patients perceived the system as acceptable and effective.The encouraging results of this study provide a strong rationale for a long-term, randomized, clinical trial to determine whether this home BP tele-management system improves BP control in the community among patients with uncontrolled hypertension.

Abstract: Each mobile phone with a built-in CMOS sensor can inherently be seen as sophisticated optical sensor being able to analyze its environment in terms of visual events and its own mobility. Due to mass production their price decreases steadily, although their processing capacity increases. Mobile phones are usually attached to people, who are driven by mobility. We define activities arising from this mobility as internal activities in contrast to external activities, that are caused by visual events. Both activities can be recognized by measuring the sensor’s optical flow. We present a method to identify internal activities based on optical flow measurements and probabilistic reasoning. We implement a lifelogging application, running on a Linux-based mobile phone, that can detect internal activities such as moving left-hand, right-hand or walking with a recognition rate of 80%. While standing still external activities are recognized using object detection. 1

The need for increased individual mobility has resulted in a significant and continuous increase of road traffic density. More and more, the roads are getting congested. Modern Intelligent Transportation Systems (ITS) are offering methods to avoid these congestions. However, this requires a dense surveillance system of sensors that is very costly. Thus, due to financial constraints, not all roads are

This article presents the Mobile Century field experiment, performed on February 8, 2008, to demonstrate the feasibility of a prototype location-based service: real-time traffic estimation using GPS data from cellular phones only. Mobile Century consisted of 100 vehicles carrying a GPS-equipped Nokia N95 cell phone driving loops on a 10-mile stretch of I-880 between Hayward and Fremont, California. The data obtained in the experiment was processed in real-time and broadcasted on the internet for 8 hours. Travel time and velocity contour estimates were shown in real-time using a privacy-preserving architecture developed to provide this new service in an environment acceptable to users and participants. The quality of the data proves to be accurate against data obtained independently from the experiment. The experiment also shows that it is not necessary to have a high proportion of equipped vehicles to obtain accurate results, confirming that GPS-enabled cell phones can realistically be used as traffic sensors, while preserving individuals' privacy.

Recent developments in publically available webbased Geographical Information Systems (GIS) and the availability of low-cost integrated General Packet Radio Service (GPRS)/Global Positioning Systems (GPS) modem have enabled the development of embedded stand-alone home monitoring systems. This paper presents the design, implementation and testing of a home-monitoring system that utilizes online Map from a GIS in conjunction with the readily available public satellite-based GPS, and GPRS mobile networks. In addition to detecting intruders, the system allows a home owner to remotely monitor various critical home sensors status including those tied to fire, flooding, and gas leaks. Home owners can monitor their homes via their mobile phone or by using the Internet. This system can also be utilized by security firms, civil defense organizations and municipalities to continuously monitor and locate troublesome spots in residential neighborhoods and compounds using free GIS Maps 1 .

Multimodal interaction is becoming common in many kinds of devices, particularly mobile phones. If care is not taken in design and implementation, there may be latencies in the timing of feedback in the different modalities may have unintended effects on users. This paper introduces an easy to implement multimodal latency measurement tool for touchscreen interaction. It uses off-the-shelf components and

In current authoring tools for location-aware applications the designer typically places trigger zones onto a map of the target environment and associates these with events and media assets. However, studies of deployed experiences have shown that the characteristics of the usually invisible ubiquitous computing infrastructure, especially limited coverage and accuracy, have a major impact on an experience. We propose a new approach in which designers work with three layers of information: information about the physical world, information about digital media, but also visualizations of ubiquitous infrastructure. We describe the implementation of a prototype authoring tool that embodies this approach and describe how it has been used to author a location-based game for mobile phones called Tycoon. We then outline the key challenges involved in generalizing this approach to more powerful authoring tools including acquiring and visualizing infrastructure data, acquiring map data, and flexibly specifying how digital content relates to both of these.

The evolution of information and communications technology, together with the increasing use of electronic commerce, phones and mobile applications, have facilitated mobile payments to become an alternative payment method for buyers and vendors. Mobile payments offer various opportunities to business environment and became a starting point in the transition from electronic to mobile. This paper aims to analyze the present situation of the mobile payment methods and to identify the effects that mobile payment systems have on electronic commerce.

Mobile phones have been shown effective in several public health domains. However, there are few evaluations of the effectiveness of mobile health in health promotion. Also, although many studies have referenced behavioral theory, none appears to have explicitly tested theoretical assumptions or demonstrated mechanisms of change. More robust evaluation models that incorporate theory and measurement of behavioral mediators are needed. As in all public health programs, mobile health operates within a social ecological context. For example, organizational- and individual-level programs seek to influence health and health care practices and individual health behaviors. New programs such as Text4baby demonstrate how theory and explicit testing of mediators can be incorporated in evaluations. There are challenges and opportunities facing mHealth evaluations given the nature of the mobile channel. Mobile communication is ubiquitous, available at all times and places, and thus experimental control is often difficult. Natural experiments using variation in dosage of mHealth and place- or location-based designs may increase experimental control. Text4baby is a text messaging program that provides prenatal care messages to pregnant women and new mothers. It uses a partnership model with health care facilities often serving as local implementation partners. The authors review a case example of the evaluation of Text4baby at Madigan Army Medical Center. Participants were randomized to usual prenatal care plus text messaging or usual care alone. The evaluation has a theoretical model of behavior change and measures mediators as well as behavioral outcomes. Results will inform how behavioral theory works within mobile health programs.

Today, people are making use of several devices for communications, for accessing multi-media content services, for data/information retrieving, for processing, computing, etc.: examples are laptops, PDAs, mobile phones, digital cameras, mp3 players, smart cards and smart appliances. One of the most attracting service scenarios for future Telecommunications and Internet is the one where people will be able to browse any

This paper presents the socio-economic profile of households in the Family Dynamics Study (FDS) (1997-2001) and makes comparisons with the earlier Functional Groups Study (FGS) (1992-1996). For the current study, FGS villages with a high prevalence of child malnutrition were purposively selected. In each village selected, all households were included, and interviews with a structured questionnaire were conducted in April-May 1998. Incomes were generally low and incidence of poverty was high; 49.6% of the households were under the poverty line income, of which 37.2% were poor and 12.4% were hard core poor. Overall, only 23.2% of heads of households were in agricultural occupations, others being primarily waged workers and petty traders. Livestock rearing was widespread (57.8%), and most households (90.4%) owned at least one motorised vehicle, the most common being the motorcycle. The majority of households had refrigerators (73.6%), washing machines (58.8%), and televisions (91.1%); ...

This paper describes an ingenious way of using Bluetooth-Enabled Mobile Phones to control the PC applications with the help of a Software Application, which is based on Client Server architecture. The application "Application Remote Control using Bluetooth" or (ARC) along with the Mobile Phone possess the ability to control various Software Applications such as Windows Media Player and Microsoft PowerPoint Slideshows. It can also control electrical devices such as LEDs, fans using parallel (LPT) port of the PC, and PC monitor.

Over the last decade the mobile phone has become a rapidly emerging technology presenting both opportunities and challenges to many areas of the social landscape, including higher education. The purpose of this study was to explore some of the challenges associated with mobile phones in college classrooms. A sample of faculty and students was surveyed to assess the extent to which the technology is considered a serious source of distraction in the classroom, concerns about use of the technology for cheating, and attitudes about policies restricting it from ringing and being used during class. Collectively, participants reported strong perceptions of ringing as a problem and support for formal policies restricting mobile phones in college classrooms. Faculty/student status was not related to any of the attitude measures, but age consistently was. Younger participants tended to be more tolerant of mobile phone interruptions during class and reported less support for policies restricting ringing and use. The discussion offers implications and avenues for future research.

The paper presents an empirical model of acceptance of mobile phones by elderly people. It is based on an extension of the widely used TAM-Technology Acceptance Model and aims specifically at investigating the relationship among intrinsic and extrinsic motivations to use. The data consists of 740 questionnaires from people over 65 years old. The validated model shows that intrinsic motivations play an important role albeit always mediated by utilitarian motives. Similarly, it emerges a strong influence of the reference social group (children and relatives) in increasing the utilitarian values of the use of mobile phones. These findings suggest that mobile phone usage by elderly might not be, after all, too much different, from a motivational point of view, from that of younger or adult people.

This work confers an application which makes possible to use a Bluetooth enabled mobile phone to remote control home appliances such electric fan, LEDs and stepper motor, connected to the personal computer. It can also be used to control other computer applications such as multimedia players and facilitates the user while giving presentation on slides. It is a client-server based application which makes use of powerful java technology to achieve its end. The program works on a variety of Bluetooth enabled mobile phone and is compatible with majority of Bluetooth stacks.

INTRODUCTION: Mobile phone dependence has become an emerging public health problem. This cross-sectional study was conducted to find out the mobile phone involvement and dependence among undergraduate medical students in a Medical College of West Bengal, India. MATERIALS AND METHODS: A study was conducted at IQ City Medical College, Durgapur, District Burdwan, West Bengal, India, during July–August 2015 among 252 undergraduate medical students. Involvement and dependence were elicited by mobile phone involvement questionnaire (MPIQ) and mobile phone dependence questionnaire (MPDQ), respectively. Statistical Package for the Social Sciences (SPSS) software (version 19.0) was used for analysis. RESULTS: About 14.9% of students were being highly involved with their mobile phone. The mean score of MPIQ was greatest in domain 5, i.e. euphoria followed by domain 2, i.e. behavioral salience and then domain 4, i.e. conflict with other activities. About 19.4% of males and 11.1% of females had...

The power of the handheld electronics devices continues to increase because packaging advances reduce their size even as more features are added and enhanced. The computational fluid dynamics (CFD) numerical simulation is performed on thermal management of the mobile phone using a heat storage unit (HSU) filled with the phase change material (PCM). The chips and HSU are embedded in an epoxy polymer casing. The PCM absorbs the heat dissipation from the chips and stores as latent heat to maintain the chip temperature below the allowable service temperature. Eight cases of simulations are carried out with or without PCM at several power dissipations. The use of PCM in mobile phone has shown to be effective in keeping the chip temperature down to acceptable level for certain duration.

The present research investigated and studied students&#x27; representations about daily life technologies, in a prospect of studying technology in Greek primary education. In the research participated 60 Greek primary school students aged 9 to 12 years old. Re- search data were collected through semi-structured, personal, clinical-type interviews. Each interview investigated student&#x27;s conceptions and views about the following thematic areas: the

Mobile visualisation of map-based information is a difficult task. Designers of such systems must contend with the limitations of mobile devices in terms of hardware, screen size and input mechanisms. These problems are exacerbated by the nature of spatial data, where a large information space needs to be presented and manipulated on a small screen. In this paper, a prototype adaptive mobile map-based visualisation system, called MediaMaps, is presented. MediaMaps allows users to capture, location-tag, sort and browse multimedia in a map-based view. MediaMaps was designed to adapt the information visualised, the map-based visualisations and the supporting user interface. The results of an international field study, in which participants used MediaMaps on their personal mobile phones for a three-week period, are also presented. These results show that the adaptations implemented achieved high levels of accuracy and user satisfaction and successfully addressed some of the limitations ...

We examine the emotional impact caused to victims of bullying in its traditional form, both directly and indirectly, as well as bullying inflicted by use of new technologies such as mobile phones and the Internet. A sample of 1,671 adolescents and young people responded to a questionnaire which asked if they had been victims of various forms of bullying, as well as the emotions this caused. The results show that although traditional bullying affected significantly more young people than cyberbullying, the latter affected one in ten adolescents. Analysis of the emotions caused showed that traditional bullying produced a wide variety of impacts, with the victims being divided into five different emotional categories, while indirect bullying and cyberbullying presented a narrower variety of results with the victims being classifiable into just two groups: Those who said that they had not been emotionally affected and those who simultaneously suffered from a wide variety of negative emotions. The influence of age, gender, and severity on each emotional category is also analyzed.

The explosion of mobile phones into a region that, until recently, was nearly devoid of telecommunications infrastructure provides a valuable opportunity to explore the potential effects of information and communication technology on various economic and social outcomes. This article focuses specifically on the potential influence that mobile phones will exert on corruption in Africa. Two distinct empirical analyses test the

The trajectory from alcohol use to alcohol use disorders in adolescence is yet to be understood. Momentary sampling may assist in capturing &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;real-time&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; data on young people&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s alcohol use and associated motivational factors. This paper aims to review the feasibility and usefulness of a mobile phone momentary sampling program to capture data about alcohol use and related behaviours. Two studies were conducted: a school-based study with 18 Year 9 and 11 students and a clinical study with eight high-risk adolescent drinkers. Participants answered questions about their daily activities, alcohol use, stressors and negative mood four times a day for 1 week using a mobile phone momentary sampling program. In the school-based study, 61% of participants reported drinking alcohol. On drinking days participants spent less time studying (14% vs. 26%), more time sleeping or resting (35% vs. 12%) and more time hanging out (21% vs. 11%) than on non-drinking days. In the high-risk sample, 88% of participants reported drinking alcohol. On drinking days, these participants spent a greater proportion of their waking time with their boyfriend or girlfriend (19.2% vs. 6%) and generally had higher negative mood than on non-drinking days. The current mobiletype program was well suited to capturing data on alcohol use in younger, school-attending adolescents. However, to capture alcohol use in older adolescents who lead less routine lives, it is necessary to make some amendments including targeting particular behaviours and symptoms. Recommendations for future studies are proposed.

This paper examines the effects of systematic and random errors in recall and of selection bias in case-control studies of mobile phone use and cancer. These sensitivity analyses are based on Monte-Carlo computer simulations and were carried out within the INTERPHONE Study, an international collaborative case-control study in 13 countries. Recall error scenarios simulated plausible values of random and systematic, non-differential and differential recall errors in amount of mobile phone use reported by study subjects. Plausible values for the recall error were obtained from validation studies. Selection bias scenarios assumed varying selection probabilities for cases and controls, mobile phone users, and non-users. Where possible these selection probabilities were based on existing information from non-respondents in INTERPHONE. Simulations used exposure distributions based on existing INTERPHONE data and assumed varying levels of the true risk of brain cancer related to mobile phone use. Results suggest that random recall errors of plausible levels can lead to a large underestimation in the risk of brain cancer associated with mobile phone use. Random errors were found to have larger impact than plausible systematic errors. Differential errors in recall had very little additional impact in the presence of large random errors. Selection bias resulting from underselection of unexposed controls led to J-shaped exposure-response patterns, with risk apparently decreasing at low to moderate exposure levels. The present results, in conjunction with those of the validation studies conducted within the INTERPHONE study, will play an important role in the interpretation of existing and future case-control studies of mobile phone use and cancer risk, including the INTERPHONE study.