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Toppage > Activities > Symposium Fiscal 2006 ITS Info-communications Forum Symposium Report 5. Lecture 3 Wireless Technology in a Ubiquitous Age Seiichi Sampei Professor, Graduate School of Engineering Osaka University <Abstract> In the first 50 years of its 100-year history, wireless communications was used only in limited fields. However, following the dissemination of mobile telephone use (1995-2000), wireless technologies have become strong tools for the advancement of multimedia. Historically speaking, in the 1960s and 70s, the use of wireless technologies in generally known communications environments consisted only of television, radio, radar, amateur radio communications, etc. However, since the 1990s, new applications such as POS (Point of Sales) systems, new-generation mobile telephones, car navigation systems, and remote sensing systems have made wireless technologies more and more popular. After the year 2000, RFID (Radio Frequency Identification) and sensor networks appeared. Today, our theme, ITS (Intelligent Transport Systems), and the IT (information technologies) and radar technologies incorporated in it, are used in our daily lives. The reliability of wireless communications has been one of our concerns. Additionally, the quality of wireless communications was considered to be poor. This was mainly due to propagation path characteristics, which made it very difficult to design a wireless system, especially in the 1980s. But as the era changed, compliance paradigms shifted as well. In the 1990s, when the handheld-type mobile telephone (digital system) was standardized, the system design strategy was to apply narrowband transmission technologies to prevent channel distortion caused by the propagation path. However, the design strategy changed-from narrowband to wideband-because increasing the transmission bandwidth can mitigate rapid fluctuation of the received signal level as the result of energy dispersion in the frequency domain. Therefore, we found that the transmission quality of wireless communication systems could be stabilized by increasing the bandwidth. Of course, the bandwidth has limitations due to spectrum allocation by authorities. So, residual signal level fluctuation needs to be suppressed using other means such as diverse technologies. As a result of these technological innovations, it was confirmed that we could use technologies to improve the transmission quality of wireless communication systems. The 1990s to 2000 was the era of research and development for what is now referred to worldwide as third-generation systems; a time when we fought furiously at the global level, and our ideas changed to take a positive initiative against fading. Triggering that paradigm shift was the transmission power control currently used in CDMA (Code Division Multiple Access) systems; in other words, controlling the transmitter could overcome fading problems. Moreover, the use of embedded propagation path measuring schemes made it possible to introduce adaptive control in both the transmitter and receiver, whereby it was possible to flexibly control the influence of fading (i.e., equivalent creation of fade-free conditions). With this, the Shannon Theory (Shannon Limit), introduced 50 years earlier, finally became reality. The abovementioned is the background for today's advances in broadband wireless technologies. After 2000, the concept changed even further. We now have technologies that give fading phenomena a major role in wireless technologies, whereas it was the most serious troublemaker beforehand. An example is MIMO (Multiple Input/Multiple Output) transmission. This is also a part of the drastic change of wireless communication systems from band-limited systems to power-limited systems. More simply, how to design a wireless system under power-limited conditions is the most important challenge for future ubiquitous systems. We have entered a multimedia era where various technologies are being utilized. For example, in the area of mobile telephone development, voice communication technologies introduced in first-generation systems are still being used, and e-mail and Web capabilities such as i-mode and EZ-Web that appeared in second-generation systems have led to the exponential spread of devices such as cameras being built into mobile telephones. This can be said to be one of the footholds of multimedia at that point in time. Next, locations services that allow subscribers to access various information from databases using mobile communications devices were introduced, and video/movie and music download services appeared along with third-generation systems. Based on these activities, multimedia services being provided by third-generation mobile telephone carriers are presently moving in the direction of broadband applications. Technological progress has been supported by the mobile telephone up to now. The main reason for using wireless technologies in the past was that "no cords were required." However, nowadays, wireless is used not only to transfer information, but also to identify the conditions of something or transmit information (i.e., unlike the Internet, from which information is mainly obtained). Sensor networks and ITS are more active systems that receive and send data via networks in a more interactive way. The difficulty at this time is creating networks that obtain the necessary information when it is needed. Non-contact, such as measuring something without any contact, is another important requirement. It is important to note that wireless technologies of this kind can be utilized for many things in our daily lives. An important point is that people should not be conscious of the system's existence; not only the computer, but the network as well. That is, ensuring that the required information is received in the desired form without being aware of the system. "Ubiquitous" does not mean that everything is connected; it means having a system, infrastructure and various things that enable information that is needed to be accessed in a timely manner. From now on, it is important that ubiquity focus on personal space, enabling individuals to create personalized data. What is meant here is that space can be utilized jointly to a wider extent. As for individual space, one can have his/her own private space and share common space. It is vital that ubiquity not only offers the connection, but also enables individuals to jointly share the space. The roles of ITS in a ubiquitous network society are providing "safety and security" and "traffic information," tasks that require the most advanced technologies using radio waves. Regarding information, a receiver cannot obtain information until it is provided, so the important mission for the receiver in a ubiquitous network society is how to utilize the information received. A collision accident must certainly have a causal relationship. When driving a vehicle, it is commonly said that a driver who is not used to driving in dense traffic watches only the vehicle immediately in front of him/her. If that inexperienced driver is asked to pay attention to the vehicle two cars ahead, it is possible that the driver would focus on only that vehicle. In this sense, the time series of information and precise methods for receiving information are very important. The information must be provided instantly, and that information must be correct and understood. As a definition of ITS, it is an info-communications system for realizing a smooth traffic system by understanding the necessary circumstances quickly and corresponding accordingly at any location. Regarding the role of radio waves in ubiquitous networks, it can be said that sensing functions (i.e. measurement functions) utilizing radio waves are well utilized for many systems and technologies. I understand that ITS is a system in which these functions are emphasized and focused. From this time onward, ITS will be playing an important role as a part of the ubiquitous network society. It is said that it will be a cornerstone in U-Japan (Ubiquitous Japan), and that is my expectation too.
5. Lecture 3 Wireless Technology in a Ubiquitous Age Seiichi Sampei Professor, Graduate School of Engineering Osaka University <Abstract> In the first 50 years of its 100-year history, wireless communications was used only in limited fields. However, following the dissemination of mobile telephone use (1995-2000), wireless technologies have become strong tools for the advancement of multimedia. Historically speaking, in the 1960s and 70s, the use of wireless technologies in generally known communications environments consisted only of television, radio, radar, amateur radio communications, etc. However, since the 1990s, new applications such as POS (Point of Sales) systems, new-generation mobile telephones, car navigation systems, and remote sensing systems have made wireless technologies more and more popular. After the year 2000, RFID (Radio Frequency Identification) and sensor networks appeared. Today, our theme, ITS (Intelligent Transport Systems), and the IT (information technologies) and radar technologies incorporated in it, are used in our daily lives. The reliability of wireless communications has been one of our concerns. Additionally, the quality of wireless communications was considered to be poor. This was mainly due to propagation path characteristics, which made it very difficult to design a wireless system, especially in the 1980s. But as the era changed, compliance paradigms shifted as well. In the 1990s, when the handheld-type mobile telephone (digital system) was standardized, the system design strategy was to apply narrowband transmission technologies to prevent channel distortion caused by the propagation path. However, the design strategy changed-from narrowband to wideband-because increasing the transmission bandwidth can mitigate rapid fluctuation of the received signal level as the result of energy dispersion in the frequency domain. Therefore, we found that the transmission quality of wireless communication systems could be stabilized by increasing the bandwidth. Of course, the bandwidth has limitations due to spectrum allocation by authorities. So, residual signal level fluctuation needs to be suppressed using other means such as diverse technologies. As a result of these technological innovations, it was confirmed that we could use technologies to improve the transmission quality of wireless communication systems. The 1990s to 2000 was the era of research and development for what is now referred to worldwide as third-generation systems; a time when we fought furiously at the global level, and our ideas changed to take a positive initiative against fading. Triggering that paradigm shift was the transmission power control currently used in CDMA (Code Division Multiple Access) systems; in other words, controlling the transmitter could overcome fading problems. Moreover, the use of embedded propagation path measuring schemes made it possible to introduce adaptive control in both the transmitter and receiver, whereby it was possible to flexibly control the influence of fading (i.e., equivalent creation of fade-free conditions). With this, the Shannon Theory (Shannon Limit), introduced 50 years earlier, finally became reality. The abovementioned is the background for today's advances in broadband wireless technologies. After 2000, the concept changed even further. We now have technologies that give fading phenomena a major role in wireless technologies, whereas it was the most serious troublemaker beforehand. An example is MIMO (Multiple Input/Multiple Output) transmission. This is also a part of the drastic change of wireless communication systems from band-limited systems to power-limited systems. More simply, how to design a wireless system under power-limited conditions is the most important challenge for future ubiquitous systems. We have entered a multimedia era where various technologies are being utilized. For example, in the area of mobile telephone development, voice communication technologies introduced in first-generation systems are still being used, and e-mail and Web capabilities such as i-mode and EZ-Web that appeared in second-generation systems have led to the exponential spread of devices such as cameras being built into mobile telephones. This can be said to be one of the footholds of multimedia at that point in time. Next, locations services that allow subscribers to access various information from databases using mobile communications devices were introduced, and video/movie and music download services appeared along with third-generation systems. Based on these activities, multimedia services being provided by third-generation mobile telephone carriers are presently moving in the direction of broadband applications. Technological progress has been supported by the mobile telephone up to now. The main reason for using wireless technologies in the past was that "no cords were required." However, nowadays, wireless is used not only to transfer information, but also to identify the conditions of something or transmit information (i.e., unlike the Internet, from which information is mainly obtained). Sensor networks and ITS are more active systems that receive and send data via networks in a more interactive way. The difficulty at this time is creating networks that obtain the necessary information when it is needed. Non-contact, such as measuring something without any contact, is another important requirement. It is important to note that wireless technologies of this kind can be utilized for many things in our daily lives. An important point is that people should not be conscious of the system's existence; not only the computer, but the network as well. That is, ensuring that the required information is received in the desired form without being aware of the system. "Ubiquitous" does not mean that everything is connected; it means having a system, infrastructure and various things that enable information that is needed to be accessed in a timely manner. From now on, it is important that ubiquity focus on personal space, enabling individuals to create personalized data. What is meant here is that space can be utilized jointly to a wider extent. As for individual space, one can have his/her own private space and share common space. It is vital that ubiquity not only offers the connection, but also enables individuals to jointly share the space. The roles of ITS in a ubiquitous network society are providing "safety and security" and "traffic information," tasks that require the most advanced technologies using radio waves. Regarding information, a receiver cannot obtain information until it is provided, so the important mission for the receiver in a ubiquitous network society is how to utilize the information received. A collision accident must certainly have a causal relationship. When driving a vehicle, it is commonly said that a driver who is not used to driving in dense traffic watches only the vehicle immediately in front of him/her. If that inexperienced driver is asked to pay attention to the vehicle two cars ahead, it is possible that the driver would focus on only that vehicle. In this sense, the time series of information and precise methods for receiving information are very important. The information must be provided instantly, and that information must be correct and understood. As a definition of ITS, it is an info-communications system for realizing a smooth traffic system by understanding the necessary circumstances quickly and corresponding accordingly at any location. Regarding the role of radio waves in ubiquitous networks, it can be said that sensing functions (i.e. measurement functions) utilizing radio waves are well utilized for many systems and technologies. I understand that ITS is a system in which these functions are emphasized and focused. From this time onward, ITS will be playing an important role as a part of the ubiquitous network society. It is said that it will be a cornerstone in U-Japan (Ubiquitous Japan), and that is my expectation too.
<Abstract> In the first 50 years of its 100-year history, wireless communications was used only in limited fields. However, following the dissemination of mobile telephone use (1995-2000), wireless technologies have become strong tools for the advancement of multimedia. Historically speaking, in the 1960s and 70s, the use of wireless technologies in generally known communications environments consisted only of television, radio, radar, amateur radio communications, etc. However, since the 1990s, new applications such as POS (Point of Sales) systems, new-generation mobile telephones, car navigation systems, and remote sensing systems have made wireless technologies more and more popular. After the year 2000, RFID (Radio Frequency Identification) and sensor networks appeared. Today, our theme, ITS (Intelligent Transport Systems), and the IT (information technologies) and radar technologies incorporated in it, are used in our daily lives. The reliability of wireless communications has been one of our concerns. Additionally, the quality of wireless communications was considered to be poor. This was mainly due to propagation path characteristics, which made it very difficult to design a wireless system, especially in the 1980s. But as the era changed, compliance paradigms shifted as well. In the 1990s, when the handheld-type mobile telephone (digital system) was standardized, the system design strategy was to apply narrowband transmission technologies to prevent channel distortion caused by the propagation path. However, the design strategy changed-from narrowband to wideband-because increasing the transmission bandwidth can mitigate rapid fluctuation of the received signal level as the result of energy dispersion in the frequency domain. Therefore, we found that the transmission quality of wireless communication systems could be stabilized by increasing the bandwidth. Of course, the bandwidth has limitations due to spectrum allocation by authorities. So, residual signal level fluctuation needs to be suppressed using other means such as diverse technologies. As a result of these technological innovations, it was confirmed that we could use technologies to improve the transmission quality of wireless communication systems. The 1990s to 2000 was the era of research and development for what is now referred to worldwide as third-generation systems; a time when we fought furiously at the global level, and our ideas changed to take a positive initiative against fading. Triggering that paradigm shift was the transmission power control currently used in CDMA (Code Division Multiple Access) systems; in other words, controlling the transmitter could overcome fading problems. Moreover, the use of embedded propagation path measuring schemes made it possible to introduce adaptive control in both the transmitter and receiver, whereby it was possible to flexibly control the influence of fading (i.e., equivalent creation of fade-free conditions). With this, the Shannon Theory (Shannon Limit), introduced 50 years earlier, finally became reality. The abovementioned is the background for today's advances in broadband wireless technologies. After 2000, the concept changed even further. We now have technologies that give fading phenomena a major role in wireless technologies, whereas it was the most serious troublemaker beforehand. An example is MIMO (Multiple Input/Multiple Output) transmission. This is also a part of the drastic change of wireless communication systems from band-limited systems to power-limited systems. More simply, how to design a wireless system under power-limited conditions is the most important challenge for future ubiquitous systems. We have entered a multimedia era where various technologies are being utilized. For example, in the area of mobile telephone development, voice communication technologies introduced in first-generation systems are still being used, and e-mail and Web capabilities such as i-mode and EZ-Web that appeared in second-generation systems have led to the exponential spread of devices such as cameras being built into mobile telephones. This can be said to be one of the footholds of multimedia at that point in time. Next, locations services that allow subscribers to access various information from databases using mobile communications devices were introduced, and video/movie and music download services appeared along with third-generation systems. Based on these activities, multimedia services being provided by third-generation mobile telephone carriers are presently moving in the direction of broadband applications. Technological progress has been supported by the mobile telephone up to now. The main reason for using wireless technologies in the past was that "no cords were required." However, nowadays, wireless is used not only to transfer information, but also to identify the conditions of something or transmit information (i.e., unlike the Internet, from which information is mainly obtained). Sensor networks and ITS are more active systems that receive and send data via networks in a more interactive way. The difficulty at this time is creating networks that obtain the necessary information when it is needed. Non-contact, such as measuring something without any contact, is another important requirement. It is important to note that wireless technologies of this kind can be utilized for many things in our daily lives. An important point is that people should not be conscious of the system's existence; not only the computer, but the network as well. That is, ensuring that the required information is received in the desired form without being aware of the system. "Ubiquitous" does not mean that everything is connected; it means having a system, infrastructure and various things that enable information that is needed to be accessed in a timely manner. From now on, it is important that ubiquity focus on personal space, enabling individuals to create personalized data. What is meant here is that space can be utilized jointly to a wider extent. As for individual space, one can have his/her own private space and share common space. It is vital that ubiquity not only offers the connection, but also enables individuals to jointly share the space. The roles of ITS in a ubiquitous network society are providing "safety and security" and "traffic information," tasks that require the most advanced technologies using radio waves. Regarding information, a receiver cannot obtain information until it is provided, so the important mission for the receiver in a ubiquitous network society is how to utilize the information received. A collision accident must certainly have a causal relationship. When driving a vehicle, it is commonly said that a driver who is not used to driving in dense traffic watches only the vehicle immediately in front of him/her. If that inexperienced driver is asked to pay attention to the vehicle two cars ahead, it is possible that the driver would focus on only that vehicle. In this sense, the time series of information and precise methods for receiving information are very important. The information must be provided instantly, and that information must be correct and understood. As a definition of ITS, it is an info-communications system for realizing a smooth traffic system by understanding the necessary circumstances quickly and corresponding accordingly at any location. Regarding the role of radio waves in ubiquitous networks, it can be said that sensing functions (i.e. measurement functions) utilizing radio waves are well utilized for many systems and technologies. I understand that ITS is a system in which these functions are emphasized and focused. From this time onward, ITS will be playing an important role as a part of the ubiquitous network society. It is said that it will be a cornerstone in U-Japan (Ubiquitous Japan), and that is my expectation too.
The reliability of wireless communications has been one of our concerns. Additionally, the quality of wireless communications was considered to be poor. This was mainly due to propagation path characteristics, which made it very difficult to design a wireless system, especially in the 1980s. But as the era changed, compliance paradigms shifted as well. In the 1990s, when the handheld-type mobile telephone (digital system) was standardized, the system design strategy was to apply narrowband transmission technologies to prevent channel distortion caused by the propagation path. However, the design strategy changed-from narrowband to wideband-because increasing the transmission bandwidth can mitigate rapid fluctuation of the received signal level as the result of energy dispersion in the frequency domain. Therefore, we found that the transmission quality of wireless communication systems could be stabilized by increasing the bandwidth. Of course, the bandwidth has limitations due to spectrum allocation by authorities. So, residual signal level fluctuation needs to be suppressed using other means such as diverse technologies. As a result of these technological innovations, it was confirmed that we could use technologies to improve the transmission quality of wireless communication systems.
The 1990s to 2000 was the era of research and development for what is now referred to worldwide as third-generation systems; a time when we fought furiously at the global level, and our ideas changed to take a positive initiative against fading. Triggering that paradigm shift was the transmission power control currently used in CDMA (Code Division Multiple Access) systems; in other words, controlling the transmitter could overcome fading problems. Moreover, the use of embedded propagation path measuring schemes made it possible to introduce adaptive control in both the transmitter and receiver, whereby it was possible to flexibly control the influence of fading (i.e., equivalent creation of fade-free conditions). With this, the Shannon Theory (Shannon Limit), introduced 50 years earlier, finally became reality. The abovementioned is the background for today's advances in broadband wireless technologies. After 2000, the concept changed even further. We now have technologies that give fading phenomena a major role in wireless technologies, whereas it was the most serious troublemaker beforehand. An example is MIMO (Multiple Input/Multiple Output) transmission. This is also a part of the drastic change of wireless communication systems from band-limited systems to power-limited systems. More simply, how to design a wireless system under power-limited conditions is the most important challenge for future ubiquitous systems.
We have entered a multimedia era where various technologies are being utilized. For example, in the area of mobile telephone development, voice communication technologies introduced in first-generation systems are still being used, and e-mail and Web capabilities such as i-mode and EZ-Web that appeared in second-generation systems have led to the exponential spread of devices such as cameras being built into mobile telephones. This can be said to be one of the footholds of multimedia at that point in time. Next, locations services that allow subscribers to access various information from databases using mobile communications devices were introduced, and video/movie and music download services appeared along with third-generation systems. Based on these activities, multimedia services being provided by third-generation mobile telephone carriers are presently moving in the direction of broadband applications. Technological progress has been supported by the mobile telephone up to now.
The main reason for using wireless technologies in the past was that "no cords were required." However, nowadays, wireless is used not only to transfer information, but also to identify the conditions of something or transmit information (i.e., unlike the Internet, from which information is mainly obtained). Sensor networks and ITS are more active systems that receive and send data via networks in a more interactive way. The difficulty at this time is creating networks that obtain the necessary information when it is needed. Non-contact, such as measuring something without any contact, is another important requirement. It is important to note that wireless technologies of this kind can be utilized for many things in our daily lives.
An important point is that people should not be conscious of the system's existence; not only the computer, but the network as well. That is, ensuring that the required information is received in the desired form without being aware of the system. "Ubiquitous" does not mean that everything is connected; it means having a system, infrastructure and various things that enable information that is needed to be accessed in a timely manner. From now on, it is important that ubiquity focus on personal space, enabling individuals to create personalized data. What is meant here is that space can be utilized jointly to a wider extent. As for individual space, one can have his/her own private space and share common space. It is vital that ubiquity not only offers the connection, but also enables individuals to jointly share the space.
The roles of ITS in a ubiquitous network society are providing "safety and security" and "traffic information," tasks that require the most advanced technologies using radio waves. Regarding information, a receiver cannot obtain information until it is provided, so the important mission for the receiver in a ubiquitous network society is how to utilize the information received.
A collision accident must certainly have a causal relationship. When driving a vehicle, it is commonly said that a driver who is not used to driving in dense traffic watches only the vehicle immediately in front of him/her. If that inexperienced driver is asked to pay attention to the vehicle two cars ahead, it is possible that the driver would focus on only that vehicle. In this sense, the time series of information and precise methods for receiving information are very important. The information must be provided instantly, and that information must be correct and understood. As a definition of ITS, it is an info-communications system for realizing a smooth traffic system by understanding the necessary circumstances quickly and corresponding accordingly at any location.
Regarding the role of radio waves in ubiquitous networks, it can be said that sensing functions (i.e. measurement functions) utilizing radio waves are well utilized for many systems and technologies. I understand that ITS is a system in which these functions are emphasized and focused. From this time onward, ITS will be playing an important role as a part of the ubiquitous network society. It is said that it will be a cornerstone in U-Japan (Ubiquitous Japan), and that is my expectation too.