1.1 Motivation
For the past decades communication technologies have been rapidly developed. High bandwidth and low latency wireless networks are widely used around the world, bringing additional benefits in people’s every-‐day life and assisting in making it more mobile and flexible.
Services, based on brand new communication technologies, are becoming an important functional part of the modern society. Every day more and more people rely on such services to make their phone calls, participate in videoconferences while travelling in a high-‐speed train, securely backup sensitive data, use location services in unknown environment both for business and pleasure, etc. In other words, mobility brings a new level of freedom and enriches the quality of the everyday life.
Additionally, as a result of a huge and continuously growing market of handheld appliances, the mobile devices are getting easier to get and afford.
Thank to prerequisites mentioned above, communication services are nowadays in a huge demand not only in business sector and end-‐user applications, but also in a health care environment.
Turning to the health care field, needless to say that in the recent years plenty successful projects have been completed in order to help visually impaired and blind people to use modern communication techniques equally with the sighted people. These include web browsing, emailing (both sending and receiving), and many more.
In spite of the mentioned above, it would be fair to notice that still in the most of the cases visually impaired and blind people are limited in mobility. Therefore, development of special infrastructures can not only enrich mobility of visually impaired people, but also bring additional sense of security to their lives. As mentioned in [2], “visually impaired or blind persons rely on their previous knowledge of an environment to navigate, usually getting help from guide dogs or white canes. This leaves them handicapped in achieving the desired level of mobility and context-‐awareness especially in unknown environments”.
Above all, even with traditionally accepted guidance assistants like dogs and white canes, blind people still face limitations in their usage. As fairly noticed in [7], “as societies are developed and the structure of cities is complicated, the use of both things1 became limited and restricted”.
Taking everything mentioned above into consideration, development of an infrastructure based on modern technologies could help to achieve a higher level of mobility and at the same time increase general safety of the visually impaired and blind people.
1.2 Purpose and Objectives
The purpose of this work is to propose a scenario for adopting new communication technologies together with using affordable mobile devices in order to provide assistive guidance service for visually impaired and blind people.
Based on the motivations mentioned above, the objectives for this Master thesis are the following:
• to review essential parts of related works;
• to identify the techniques that could be combined for an efficient and user-‐friendly mobile application for visually impaired/blind people;
• to specify a cloud-‐based framework for a blind navigation system 1.3 Problem statement
Although existing navigation systems partially guarantee real-‐time delivery and accuracy in traffic lights status detection, the problem of traffic lights status change prediction has not been addressed and solved. It is important to notice that prediction of traffic lights status change is an important component in an effective and safe guidance system.
When referring to system usability, there are two main types of navigation architectures for blind people: so-‐called “wearable” systems and “mobile” systems. Wearable systems consist of several hardware components combined together and are supposed to be put on a guided person. The main disadvantage in usability of these systems is that they are usually quite heavy (around 4kg). Although utilizing several hardware components allows to achieve a better accuracy and expand opportunities for useful case scenarios, these systems are not easy to wear and they may be not accepted by people for every day
1 Dogs and White canes
navigation. On the other hand, mobile types of navigation systems require only one device on a user-‐side, which guarantees a greater flexibility to a guided person. However, because of powerful hardware limitations, these systems not always can achieve same performance rate as the wearable systems. The system architecture proposed in this Master thesis addresses this issue and is aimed to find a compromise between overall system usability and system performance.
1.4 Thesis outline
The structure of this thesis is based on the determined objectives and is divided into 7 chapters.
• Chapter 1 gives the introduction to an overall view of this study; formulates purpose and objectives of this study.
• Chapter 2 focuses on theoretical background of the research and provides a literature review of the studies related to navigation systems for visually impaired/blind people.
• Chapter 3 provides detailed information about project related background, such as GPS positioning introduction, RTKLib introduction. This chapter also explains the difference between NMEA protocol and the binary protocols (like UBX). The last part of the Chapter 3 discusses Android related background together with GIS formulas and related libraries/software that are used in the proposed architecture.
• Chapter 4 describes the main requirements to the navigation system. It includes so-‐
called functional requirements and provides user case scenarios. Additionally this chapter mentions client-‐side hardware requirements.
• Chapter 5 provides information about the system architecture and implementation.
It also provides information about testing results.
• Chapter 6 gives description of testing environment and summarizes testing performance results.
• Chapter 7 summarizes the important information about the project. It includes conclusions part and future works part.