by Sung Chi Wan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 59-[63]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Design Issues in Mobile Communication Systems --- p.1 / Chapter 1.2 --- Radio Resource Management --- p.2 / Chapter 1.2.1 --- Constraint: Radio Interference --- p.2 / Chapter 1.2.2 --- Objective: High Capacity and Good Quality --- p.3 / Chapter 1.3 --- Channel Assignment --- p.3 / Chapter 1.3.1 --- Static Channel Assignment --- p.4 / Chapter 1.3.2 --- Dynamic Channel Assignment --- p.5 / Chapter 1.4 --- Review of Previous Results and Motivation --- p.6 / Chapter 1.5 --- Outline of the Thesis --- p.8 / Chapter 2 --- Static Channel Assignment --- p.9 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.2 --- Problem Formulation --- p.10 / Chapter 2.3 --- Pure Co channel Interference Case --- p.12 / Chapter 2.4 --- Systems of Special Structure --- p.16 / Chapter 2.5 --- Generalization of SP --- p.22 / Chapter 2.6 --- A Lower Bound for the General Case --- p.23 / Chapter 2.7 --- Numerical Examples --- p.25 / Chapter 2.8 --- Summary --- p.29 / Chapter 3 --- Dynamic Channel Assignment --- p.30 / Chapter 3.1 --- Introduction --- p.30 / Chapter 3.2 --- Distributed Packing Algorithm --- p.31 / Chapter 3.3 --- Performance Evaluation --- p.33 / Chapter 3.4 --- Summary --- p.38 / Chapter 4 --- Single-Channel User-Capacity Calculations --- p.39 / Chapter 4.1 --- Introduction --- p.39 / Chapter 4.2 --- Capacity as a Performance Measure --- p.40 / Chapter 4.3 --- Capacity of a Linear Celluar System --- p.41 / Chapter 4.4 --- Capacity of a 3-stripe Cellular System --- p.44 / Chapter 4.5 --- Summary --- p.46 / Chapter 5 --- Conclusion --- p.47 / Chapter 5.1 --- Summary of Results --- p.47 / Chapter 5.2 --- Suggestions for Further Research --- p.48 / Appendix --- p.49 / Chapter A --- On the Optimality of Sequential Packing --- p.49 / Chapter A.1 --- Graph Multi-coloring Problem --- p.49 / Chapter A.2 --- Sequential Packing Algorithm --- p.51 / Chapter A.3 --- Optimality of Sequential Packing --- p.52 / Chapter A.4 --- Concluding Remarks --- p.55 / Chapter B --- Derivation of the Capacity of 3-stripe system --- p.56 / Bibliography --- p.59

Intelligent devices such as smart phones, smart watches, virtual reality (VR) headsets and personal exercise devices have become integral elements of accessories used by many people. The ability of these devices to verify or identify the user could be applied for enhanced security and user experience customization among other things. Almost all these devices have built-in inertial sensors such as accelerometer and gyroscope. These inertial sensors respond to the movements made by the user while performing day to day activities like walking, getting up and sitting down. The response depends on the activity being performed and thus can be used for activity recognition. The response also captures the user's unique way of doing the activity and can be used as a behavioral biometric for verification or identification. The acceleration (accelerometer) and rate of rotation (gyroscope) are recorded in the device coordinate frame. But to determine the user's motion, these need to be converted to a coordinate frame relative to the user. In most situations the orientation of the device relative to the user can neither be controlled nor determined reliably. The solution to this problem requires methods to remove the dependence on device orientation while comparing the signals collected at different times. In a vast of majority of research to date, the performance of authentication algorithms using inertial sensors have been evaluated on small datasets with few tens of subjects, collected under controlled placement of the sensors. Very often stand alone inertial sensors have been used to collect the data. Stand alone sensors afford better calibration, while the sensors built into smart devices offer little or no means of calibration. Due to these limitations of the datasets used, it is difficult to extend the results from these research to realistic performance with a large number subjects and natural placement of off-the-shelf smart devices. This dissertation describes the Kabsch algorithm which is used to achieve orientation invariance of the recorded inertial data, enabling better authentication independent of device orientation. It also presents the Vector Cross Product (VCP) method developed to achieve orientation invariance. Details of a realistic inertial dataset (USF-PDA dataset) collected with commercial smart phones placed in natural positions and orientations using 101 subjects are given. The data includes sessions from different days on a subset of 56 subjects. This would enable realistic evaluation of authentication algorithms. This dataset has been made publicly available. The performance of five methods that address the orientation dependence of signals are compared to a baseline that performs no compensation for orientation of the device. The methods as a part of a overall gait authentication algorithm are evaluated on the USF-PDA dataset mentioned above and another large dataset with more than 400 subjects. The results show that the orientation compensation methods are able to improve the authentication performance on data with uncontrolled orientation to be close to performance on data collected with controlled orientation. The Kabsch method shows the highest improvement.

With the development of hardware, mobile phone has become a feature-rich handheld device. Built-in camera and Bluetooth technology are supported in most current mobile phones. A real-time image processing experiment was conducted with a SonyEricsson P910i smartphone and a desktop computer. This thesis describes the design and implementation of a system which uses a mobile phone as a PC mouse. The movement of the mobile phone can be detected by analyzing the images captured by the onboard camera and the mouse cursor in the PC can be controlled by the movement of the phone.

<p>MindMe is an aid for people with cognitive memory impairments. The aid is completely new and has been</p><p>developed within this bachelor thesis, no product of this nature could be found on the market before. The</p><p>idea came from Niclas Jarhäll, CEO of Mutual Benefits. Mutual Benefits were also partners in the project.</p><p>The project was carried out by us in cooperation with Bachelor of Science in Innovation Engineering</p><p>students Malin Albertsson and Victoria Hedman at Halmstad university. The aid consists of a mobile phone</p><p>and a number of tags. The goal was for the mobile phone and tag to set of their alarms when they get a</p><p>certain distance apart.</p><p>It is the technical part of the project that will be discussed in this paper and it was divided in two parts,</p><p>prototype development and software for the mobile phone.</p><p>The project resulted in a prototype and an application for the mobile phone. The prototype and mobile phone</p><p>set of their alarms when they come to far apart. The user has the option to change settings in the mobile</p><p>phone application that affects both phone and tag and to add/remove tags. Both application and tag meet the</p><p>requirements set in the technical specification.</p>

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This thesis investigates the suitability of global navigation satellite system (GNSS) signals for cellular phone location. The requirement is to determine and report the location of a phone during an emergency call.<p> The thesis analyzes acquisition and tracking techniques suitable for very weak signals as received by a cellular phone indoors. The L1 and L5 signals from GPS satellites and the L1 signal from Galileo satellites are considered. It is shown that long integration times and coherent integration are required for the weakest expected signals. Long coherent integration times require a precise knowledge of the Doppler shift due to the range rate of the satellite. The tolerance to Doppler shift can be increased by using FFTs in the analysis of the data. Non-coherent averaging techniques improve the Doppler tolerance but compared to coherent averaging, the loss of signal to noise ratio is too large for the weakest signals.<p> Coherent averaging of the GPS L1 signal requires data removal that can be accomplished with assistance from the cellular network. The GPS L5 and Galileo L1 signals include a data-less or pilot channel. The GPS L5 pilot channel includes a 20 bit Neuman Hoffman code with a bit period of 1 ms. This code has to be acquired or removed before coherent averaging. Similarly the Galileo pilot channel includes a 25 bit short code.<p> Once code acquisition has been accomplished, it is necessary to track the signals from at least four satellites for long enough to compute a position estimate. A discussion of tracking techniques is included to show the signal to noise ratio limitations for adequate tracking accuracy.<p> The results show that GNSS signals are suitable for cellular phone location in a large number of situations. Increased receiver sensitivity would permit location in additional situations. In rural situations GNSS may be the only available option.

Advertising through smart phone applications is one of the fastest growing categories in advertising nowadays. Branded game-apps on mobile phones have several very innovative and attractive aspects, they physically engage their customers into a game, creating on a first level an entertainment but mainly they are advertising their products and the brand’s name. Many studies have been written on gaming, customer engagement and marketing strategies, but only few studies has been written on the convergence of mobile phone technology, gaming and marketing. This research is investigating to which extend this innovative way of marketing can be considered as an efficient marketing strategy. In order to get an insight from both sides of the market, semi-structured interviews have been lead with phone-app experts and users. Similar answers were formulated by both the producers and the users, leading me to the conclusion that a game-app is engaging the users into an overall positive dialogue with the brand. The contribution of this exploratory study is a greater understanding of the phenomenon of branded game-apps, in relation to previous studies on marketing, game mechanisms and brand-consumer relationships.

MindMe is an aid for people with cognitive memory impairments. The aid is completely new and has been developed within this bachelor thesis, no product of this nature could be found on the market before. The idea came from Niclas Jarhäll, CEO of Mutual Benefits. Mutual Benefits were also partners in the project. The project was carried out by us in cooperation with Bachelor of Science in Innovation Engineering students Malin Albertsson and Victoria Hedman at Halmstad university. The aid consists of a mobile phone and a number of tags. The goal was for the mobile phone and tag to set of their alarms when they get a certain distance apart. It is the technical part of the project that will be discussed in this paper and it was divided in two parts, prototype development and software for the mobile phone. The project resulted in a prototype and an application for the mobile phone. The prototype and mobile phone set of their alarms when they come to far apart. The user has the option to change settings in the mobile phone application that affects both phone and tag and to add/remove tags. Both application and tag meet the requirements set in the technical specification.

Malware in smartphones is growing at a significant rate. There are currently more than 250 million smartphone users in the world and this number is expected to grow in coming years.  In the past few years, smartphones have evolved from simple mobile phones into sophisticated computers. This evolution has enabled smartphone users to access and browse the Internet, to receive and send emails, SMS and MMS messages and to connect devices in order to exchange information. All of these features make the smartphone a useful tool in our daily lives, but at the same time they render it more vulnerable to attacks by malicious applications.  Given that most users store sensitive information on their mobile phones, such as phone numbers, SMS messages, emails, pictures and videos, smartphones are a very appealing target for attackers and malware developers. The need to maintain security and data confidentiality on the Android platform makes the analysis of malware on this platform an urgent issue.  We have based this report on previous approaches to the dynamic analysis of application behavior, and have adapted one approach in order to detect malware on the Android platform. The detector is embedded in a framework to collect traces from a number of real users and is based on crowdsourcing. Our framework has been tested by analyzing data collected at the central server using two types of data sets: data from artificial malware created for test purposes and data from real malware found in the wild. The method used is shown to be an effective means of isolating malware and alerting users of downloaded malware, which suggests that it has great potential for helping to stop the spread of detected malware to a larger community.  This thesis project shows that it is feasible to create an Android malware detection system with satisfactory results.

This thesis investigates the suitability of global navigation satellite system (GNSS) signals for cellular phone location. The requirement is to determine and report the location of a phone during an emergency call.<p> The thesis analyzes acquisition and tracking techniques suitable for very weak signals as received by a cellular phone indoors. The L1 and L5 signals from GPS satellites and the L1 signal from Galileo satellites are considered. It is shown that long integration times and coherent integration are required for the weakest expected signals. Long coherent integration times require a precise knowledge of the Doppler shift due to the range rate of the satellite. The tolerance to Doppler shift can be increased by using FFTs in the analysis of the data. Non-coherent averaging techniques improve the Doppler tolerance but compared to coherent averaging, the loss of signal to noise ratio is too large for the weakest signals.<p> Coherent averaging of the GPS L1 signal requires data removal that can be accomplished with assistance from the cellular network. The GPS L5 and Galileo L1 signals include a data-less or pilot channel. The GPS L5 pilot channel includes a 20 bit Neuman Hoffman code with a bit period of 1 ms. This code has to be acquired or removed before coherent averaging. Similarly the Galileo pilot channel includes a 25 bit short code.<p> Once code acquisition has been accomplished, it is necessary to track the signals from at least four satellites for long enough to compute a position estimate. A discussion of tracking techniques is included to show the signal to noise ratio limitations for adequate tracking accuracy.<p> The results show that GNSS signals are suitable for cellular phone location in a large number of situations. Increased receiver sensitivity would permit location in additional situations. In rural situations GNSS may be the only available option.