Cellular Phone Network Research Articles

Human mobility characterization from cellular network data

Anonymous location data from cellular phone networks sheds light on how people move around on a large scale.

Are information technology-based systems the way forward for diabetes management in Asia?

Are information technology-based systems the way forward for diabetes management in Asia?

L(p, q)-Labeling and Integer Flow on Planar Graphs

Given a graph G and two non-negative integers p and q, an L(p, q)-labeling c of G is an assignment of non-negative integers to the vertices of G such that, for any two vertices u and v, |c(u)-c(v)| ≥ p if d(u, v)=1 and |c(u)-c(v)| ≥ q if d(u, v)=2. The L(p, q)-labeling problem arises from a variation of the channel assignment problem. We establish a connection between the L(p, q)-labeling of the planar graph G and the integer flow on the dual graph of G. This provides us with an alternative and potentially more effective way to minimize the edge span of L(p, q)-labelings for planar graphs by using a graph flow approach. As examples, we apply this approach to determine the minimum edge spans of the L(p, q)-labelings for some typical finite planar lattices, including the square lattice, triangular lattice, hexagonal lattice as well as some other lattices consisting of various regular polygons, some of which arise from the design of planar regions for cellular phone networks. Our flow-based approach is also expected to have some further applications in optimizing the other measures for the L(p, q)-labeling problem.

Data from telecommunication networks for incident management: An exploratory review on transport safety and security

Problems such as traffic congestion and environmental sustainability are forcing us to review our long-term plans for transport, whose aim should be to develop and improve safety, security and effectiveness of the transportation systems. The consequences of traffic accidents are not only limited to road travellers (congestion, delays), but may also affect the area surrounding the incidents, for instance, the release of chemical substances. The lack of a real-time assessment of the mobility consequences of an incident, as well as of its wider consequences for the surrounding area, in terms of security and safety, hampers the decision-makers ability to respond effectively to an incident and to manage its consequences.After recognizing the great potential of electronic data in supporting traffic management and interpreting space–time geography, the paper focuses on the use of data obtained from cellular-phone networks in supporting incident management, with particular attention to transport safety and security. The literature review, coupled with the description of some illustrations of applications in the city of Amsterdam, allows highlighting the advantages and limitations of this technology in the field of transport safety and security.

Key Management Protocols for Secure Wireless Multimedia Services: A Review

With the growth of multimedia services over wireless systems, the security of communication over cellular mobile phone networks, wireless access networks, and unreliable mobile ad-hoc networks is becoming a challenging issue. Secure communication implies data confidentiality and integrity, along with authentication, bringing with it commercial viability and protection of intellectual property. Innovatory key management protocols, specialized for multimedia exchange, are now under active development. Such protocols accelerate the key management process in order not to introduce additional latency, especially at start-up time, to what are real-time services. Whereas encryption algorithms are, for reasons of open scrutiny and validation, not a subject of confidentiality, a shared secret, the session key, must be confidential and that session key relies on the existence of a secret permanent key. If a server can successfully distribute keys to remote clients without interception, the greater becomes the chance of secure communication, even though no side channel and no physical exchange of keys are required. Therefore, the focus of this review is to highlight: the key generation mechanisms, interaction with associated key management protocols; and the strength of key-management protocols against security attacks. In addition, the paper reviews recent patents on multimedia key management and also examines counter-measures present in key-management protocols against known key and data attacks. Keywords: Key management, mobile networks, multimedia, security protocols, m-commerce, MBMS, 3GPP, Cryptography, MACs, HMAC, PKI, IPTV, MCU, MANETs, MIKEY

Estimating the Quality of Service of Underground Transit Systems with Cellular Network Data

This paper shows that the particular conditions in which a cellular phone network is operated underground can make it capture a significant part of particular events like entries in tunnels. With the help of the mobile network operator Orange, some experiments have been conducted in Paris’ underground transit system. Results show that good estimates of dynamic quantities, such as travel time, passenger flow and train occupancy, can be derived from cellular data. Those estimates are used to compute two quality of service indicators: the interstation passenger density per train, and the passenger delay between an origin and a destination.

Viability of a coastal tracking and distress beacon system based on cellular phone networks

In this study a multiplatform communication system based on cellular phone networks is introduced, and the viability of its radio segment is verified. The main purpose of this beacon system is to provide real-time positioning of the coastal fleet ships or boats that habitually move in the maritime zones named A1, and to automate the distress alert signal generation.The objective of the proposed system is not to substitute but to complement other safety systems operating within very high frequency (VHF) range to increase the security of navigation in coastal areas, which will facilitate the work of maritime search and rescue teams by improving accuracy in the position tracking of boats. A measurement campaign was conducted at sea and land level to determine the viability of this GSM/GPRS-based system in terms of cellular signal power strength, data rate and error probability. Measurement outcomes have been compared with those provided by the ITU-R Recommendation P.1546-2. Results confirm its viability in terms of radio coverage and quality of service. The influence of evaporating ducts phenomena on the propagation model is discussed.

Optimizing a realistic large-scale frequency assignment problem using a new parallel evolutionary approach

This article analyses the use of a novel parallel evolutionary strategy to solve complex optimization problems. The work developed here has been focused on a relevant real-world problem from the telecommunication domain to verify the effectiveness of the approach. The problem, known as frequency assignment problem (FAP), basically consists of assigning a very small number of frequencies to a very large set of transceivers used in a cellular phone network. Real data FAP instances are very difficult to solve due to the NP-hard nature of the problem, therefore using an efficient parallel approach which makes the most of different evolutionary strategies can be considered as a good way to obtain high-quality solutions in short periods of time. Specifically, a parallel hyper-heuristic based on several meta-heuristics has been developed. After a complete experimental evaluation, results prove that the proposed approach obtains very high-quality solutions for the FAP and beats any other result published.

A realtime and continuous assessment of cortisol in ISF using electrochemical impedance spectroscopy

This study describes the functioning of a novel sensor to measure cortisol concentration in the interstitial fluid (ISF) of a human subject. ISF is extracted by means of vacuum pressure from micropores created on the stratum corneum layer of the skin. The pores are produced by focusing a near infrared laser on a layer of black dye material attached to the skin. The pores are viable for approximately three days after skin poration. Cortisol measurements are based on electrochemical impedance (EIS) technique. Gold microelectrode arrays functionalized with Dithiobis (succinimidyl propionate) self-assembled monolayer (SAM) have been used to fabricate an ultrasensitive, disposable, electrochemical cortisol immunosensor. The biosensor was successfully used for in vitro measurement of cortisol in ISF. Tests in a laboratory setup show that the sensor exhibits a linear response to cortisol concentrations in the range 1pM to 100nM. A small pilot clinical study showed that in vitro immunosensor readings, when compared with commercial evaluation using enzyme-linked immunoassay (ELISA) method, correlated well with cortisol levels in saliva and ISF. Further, circadian rhythm could be established between the subject's ISF and the saliva samples collected over 24h time-period. Cortisol levels in ISF were found reliably higher than in saliva. This research establishes the feasibility of using impedance based biosensor architecture for a disposable, wearable cortisol detector. The projected commercial in vivo real-time cortisol sensor device, besides being minimally invasive, will allow continuous ISF harvesting and cortisol monitoring over 24h even when the subject is asleep. Forthcoming, this sensor could be interfaced to a wireless health monitoring system that could transfer sensor data over existing wide-area networks such as the internet and a cellular phone network to enable real-time remote monitoring of subjects.

Prioritization Schemes in Queuing Handoff and New Calls to Reduce Call Drops in Cellular Systems

This paper proposes different queuing scenarios to avoid dropping of handoff and new calls in a cellular phone network, which is essential when the network has certain restrictions on the available frequencies. This limitation degrades the performance of the system and more sites are required to achieve the desired capacity and coverage. However, this leads to a higher percentage of call drops during handoff. This paper presents a queuing technique for both new and handoff calls to reduce the probability of call drop in such a system, leading to improvement in QoS. The proposed scenarios show better system performance. The blocking probability is reduced from 2% down to 0.04% for queuing handoff calls and from 2% to 1.14% when queuing new calls using the same technique. The four different presented approaches are: 1) only new calls are queued; 2) only handoff calls are queued; 3) by using all available channels; 4) by using only half. The queuing size also plays an important role for both new and handoff calls.

Shooter Localization in Wireless Microphone Networks

Shooter localization in a wireless network of microphones is studied. Both the acoustic muzzle blast (MB) from the gunfire and the ballistic shock wave (SW) from the bullet can be detected by the microphones and considered as measurements. The MB measurements give rise to a standard sensor network problem, similar to time difference of arrivals in cellular phone networks, and the localization accuracy is good, provided that the sensors are well synchronized compared to the MB detection accuracy. The detection times of the SW depend on both shooter position and aiming angle and may provide additional information beside the shooter location, but again this requires good synchronization. We analyze the approach to base the estimation on the time difference of MB and SW at each sensor, which becomes insensitive to synchronization inaccuracies. Cramér-Rao lower bound analysis indicates how a lower bound of the root mean square error depends on the synchronization error for the MB and the MB-SW difference, respectively. The estimation problem is formulated in a separable nonlinear least squares framework. Results from field trials with different types of ammunition show excellent accuracy using the MB-SW difference for both the position and the aiming angle of the shooter.

An Informing Service Based on Models Defined by Its Clients

Introduction Services that offer up to date information to their customers are blossoming, and their coverage is ever more extensive. In many parts of the world, it is now possible to be informed almost immediately that something has happened that either affects you or interests you in other ways. Cellular phone networks have added another dimension to the already impressive advances the Internet contributed to these possibilities of knowing what is happening. is also true that not all information received will be useful or even interesting. Thus, ample opportunities arise in the field of Informing Science (IS) to improve the informing processes. fields that comprise IS can achieve this, if the focus is to their clientele with information in a form, format, and schedule that maximizes its effectiveness (Cohen, 1999). This paper describes the informing service called FLAG, which is an acronym for Cash Flow in Agribusinesses, since it was designed specifically for that sector in Mexico, though it may just as well serve entrepreneurs of other business sectors and in any other country. Its features were designed so that the resulting service would have almost every one of the quality of information attributes cited in the Informing Science literature. In a previous paper, Cohen (1997) had remarked that the definition of IS points to three interrelated components: the client (who has a task to perform that requires information for its completion), the delivery system (for providing information), and the informing environment that creates information to aid the clients complete their tasks. FLAG initially addressed the four primary attributes of information suggested by Gackowski (2005). It must be interpretable, of significant impact, timely available and credible. In particular, timely access to information that significantly impacts the client's business, plays a fundamental role, since it may constitute a significant competitive advantage. Specifically, in the context of a business environment, Gackowski adds the all important cost elements to these attributes, formulating them in terms of the information's use in decision making or carrying out specific actions that take advantage of the information obtained. The information must be interpretable at a non-excessive cost, should be ready on time, must be credible, which implies that it must be objective, unbiased, accurate, correct, accurate and current, and must be presented in a way suitable for the receiver, so that it can be interpreted easily and without error. However, the concept of actionably timely available, formulated in that paper, is probably the most important attribute of the information a businessman needs: information that arrives too late to make a difference looses its significance. Hence, it was adopted as the guiding principle of FLAG. Additionally, since the importance of cost considerations cannot be overstated, the system would have to provide an efficient way to determine when to obtain data and which of its clients needed to be informed when changes occurred. And once again, the client will be empowered to participate actively in this determination. Birdsall (2009) formulates it concisely: The role of the client can be considered from at least two perspectives: (1) as a participant in the use of an informing process; (2) as a participant in the process of designing and developing an informing process. Of course some of the other attributes of an informing service are essential. use of mathematical models addresses mainly--but not exclusively--that the information must be interpretable and of significant impact. On the other hand, the nature of the service as a centralized mechanism for many customers to use it, should provide credibility, currency, and accurateness, especially through the careful selection of its information sources, but also through the use of the appropriate tools to obtain current values of the data it furnishes to its customers. …

Generating Origin–Destination Matrices from Mobile Phone Trajectories

This paper presents a method for generating origin–destination (O-D) matrices with the use of floating phone data, that is, data generated from mobile phones moving through a study area. Mobile phone signals recorded in the cellular phone network are used to derive time–space trajectories of moving mobile phone devices. The start and end points of each trajectory determine the origin and destination zone. Link counts are used to project the sample of mobile phone movements to the broader movement of cars, trucks, and rail passengers. With results of a clustering process of traffic counts, O-D matrices for typical traffic days are computed. The resulting O-D matrices can be used for a long-term traffic state forecast.

Evaluation of traffic data obtained via GPS-enabled mobile phones: The Mobile Century field experiment

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 h. 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. Data presented in this article can be downloaded from http://traffic.berkeley.edu.

A new generation network: Beyond the Internet and NGN

This article describes requirements and fundamental technologies to enable the provision of a new generation network beyond the Internet and the next generation network, both of which are based on IP protocols. Although the Internet has grown into a social infrastructure and the NGN will replace legacy telephone networks and cellular phone networks in the near future, it is time to start R&D on revolutionary network technologies and clean-slate designed architecture beyond the IP structure. Here some R&D activities for a new generation network are shown. This article is a revised version of the author's presentation in the First ITU-T Kaleidoscope Academic Conference held in Geneva last May.

Telecommunications in North Korea: Has Orascom Made the Connection?

IntroductionTelecommunications are one of the basic building blocks of a modern economy. In a world of globalized competition, economic development can be hamstrung by inferior telecommunications. But the formation of telecommunications policy poses a challenge for authoritarian regimes: while improvements in telecommunications can contribute to material prosperity, and by extension, political legitimacy, they may also contribute to a loss of control over information flows and enhance the ability of challengers to organize against the incumbent regime.These opposing tendencies are manifest in contemporary North Korea. The country's dilapidated telecommunications capability lags well behind world standards. The country's physical infrastructure is lacking and decrepit, with a considerable share of the general infrastructure dating back to the Japanese colonial period. Most of the modern infrastructure installed by Soviets or based on Soviet or Chinese designs is from the 1950s and 1960s. For security purposes, much of the power and telecom transmission network is buried, hampering successful maintenance. If ever there was a country that could benefit from a telecommunications upgrade, it is the DPRK.The country faces both external and self-imposed internal constraints on telecommunications modernization, however. Externally, North Korea is one of the few remaining socialist states and the most militarized country in the world. It is embroiled in a diplomatic conflict over its nuclear ambitions. The upshot is that it is subject to COCOM (Coordinating Committee for Multilateral Export Controls) restrictions under the Wassenaar Agreement, impeding its ability to import stateof-the-art technology.More fundamentally, government policies reveal an ambivalent attitude, driven by conflicting goals of modernization and control. In an attempt to make a great leap forward, the government has seized upon the promotion of information technology as a strategic priority, with P'yongyang at the top of a vertical technology hierarchy. Yet the regime repeatedly reverses field when its insecurity and instinct for control trumps development, as illustrated by the country's multiple false starts in establishing its cellular phone network, the single most frequently identified problem in doing business in North Korea in a recent survey of Chinese businesses operating there. What emerges is the primacy of political over economic concerns. Policy implicitly regards telecommunications development as a means of earning hard currency rents rather than as a tool to enhance economic efficiency and competitiveness.This paper reviews the state of North Korea's telecommunications infrastructure, though the data invoked should be considered highly provisional. Most of the information is regarded as state secrets, and some data maintained from putatively authoritative sources (e.g., statistics reported through the United Nations system) are probably estimates or have been fabricated by reporting sources. The paper also provides a brief history of North Korean telecommunications policies in a variety of settings, paying particular attention to the recent decision to authorize yet another foreign cellular provider, in this instance the Egyptian firm Orascom Telecom, to provide nationwide cellular service, potentially leapfrogging from North Korea's dilapidated existing systems to a modern system. The theme that emerges from this review is of a government that tends to place a higher value on political control than economic development. Attempts at modernization are subject to reversal at times of heightened insecurity over loss of control, yet the Orascom deal holds forth the prospect of things working out differently this time.InfrastructureLandlinesNorth Korea reports having approximately 1.1 million phone lines, amounting to less than five mainlines per 100 inhabitants. Most of these are installed in government offices, collective farms, and state-owned enterprises (SOEs), with only perhaps 10 percent controlled by individuals or households. …

Income as a determinant of the acquisition of cellular products and services by tertiary students

Cellular phones are not seen as a luxury for a select few but have become a necessity for every person and obtained for a multitude of reasons (Mutula, 2002). Students, similar to other consumers, use and consume cellular communication products and services. Profitable opportunities exist should products and services be developed to meet the specific expectations and requirements of the student cellular communication market. One element that has an influence is their available income. Information on the influence of income can help cellular telecommunication ventures to develop marketing plans for the student market. The purpose of this study was to determine whether there were any differences between high- and low-income group students in their selection of a cellular phone brand or network operator. Two hypotheses were set to determine if there would be any significant differences between the two income groups once independent decision making was possible.

Solving large-scale real-world telecommunication problems using a grid-based genetic algorithm

This article analyses the use of a grid-based genetic algorithm (GrEA) to solve a real-world instance of a problem from the telecommunication domain. The problem, known as automatic frequency planning (AFP), is used in a global system for mobile communications (GSM) networks to assign a number of fixed frequencies to a set of GSM transceivers located in the antennae of a cellular phone network. Real data instances of the AFP are very difficult to solve owing to the NP-hard nature of the problem, so combining grid computing and metaheuristics turns out to be a way to provide satisfactory solutions in a reasonable amount of time. GrEA has been deployed on a grid with up to 300 processors to solve an AFP instance of 2612 transceivers. The results not only show that significant running time reductions are achieved, but that the search capability of GrEA clearly outperforms that of the equivalent non-grid algorithm.

Implementation and Integration of Prehospital ECGs Into Systems of Care for Acute Coronary Syndrome

Clinical case: A 58-year-old woman called 9-1-1 with acute onset of chest pain that had persisted for 30 minutes. She had a history of hypertension, hyperlipidemia, and type 2 diabetes mellitus but no previous history of myocardial infarction or heart failure. Her medications included aspirin, atorvastatin, lisinopril, and metoprolol. Paramedics were dispatched, and a prehospital ECG demonstrated 3- to 4-mm ST-segment elevation in leads I, aVL, and V2 through V6 (Figure 1). Her examination revealed a regular pulse of 90 bpm, a blood pressure of 100/60 mm Hg, clear lungs, and normal heart sounds with no murmurs. Paramedics interpreted the prehospital ECG and activated the catheterization laboratory en route to the hospital. On hospital arrival, the patient was transported directly to the catheterization laboratory. Coronary angiography demonstrated an occluded proximal left anterior descending artery, which was successfully treated with balloon angioplasty and a stent. The pertinent time intervals were as follows: paramedic dispatch to balloon time, 56 minutes; paramedic arrival at the scene to balloon time, 46 minutes; hospital door to balloon time, 23 minutes. Her biomarkers revealed a peak troponin T of 2.42 ng/mL and a peak creatine kinase muscle-brain isoenzyme of 26.8 ng/mL. An echocardiogram demonstrated normal left ventricular ejection fraction of 55%, with mild anterior hypokinesis, and the patient was discharged on hospital day 3. Figure 1. Prehospital ECG. American Heart Association national guidelines,1–3 as well as other consensus and scientific statements,4–11 recommend that emergency medical services (EMS) acquire and use prehospital ECGs to evaluate patients with suspected acute coronary syndrome. Despite these recommendations, prehospital ECGs are used in fewer than 10% of patients with ST-segment–elevation myocardial infarction (STEMI),12,13 and this rate has not substantially changed since the mid-1990s. Furthermore, even when a prehospital ECG is acquired, the information is often not …

An Implementation of Wireless Medical Image Transmission System on Mobile Devices

The advanced technology of computing system was followed by the rapid improvement of medical instrumentation and patient record management system. The typical examples are hospital information system (HIS) and picture archiving and communication system (PACS), which computerized the management procedure of medical records and images in hospital. Because these systems were built and used in hospitals, doctors out of hospital have problems to access them immediately on emergent cases. To solve these problems, this paper addressed the realization of system that could transmit the images acquired by medical imaging systems in hospital to the remote doctors' handheld PDA's using CDMA cellular phone network. The system consists of server and PDA. The server was developed to manage the accounts of doctors and patients and allocate the patient images to each doctor. The PDA was developed to display patient images through remote server connection. To authenticate the personal user, remote data access (RDA) method was used in PDA accessing the server database and file transfer protocol (FTP) was used to download patient images from the remove server. In laboratory experiments, it was calculated to take ninety seconds to transmit thirty images with 832 x 488 resolution and 24 bit depth and 0.37 Mb size. This result showed that the developed system has no problems for remote doctors to receive and review the patient images immediately on emergent cases.