The wireless application protocol (WAP) protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are po...The wireless application protocol (WAP) protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are possibly infected with virus and worms. Though up to now there is no such attack, as the usage of script languages increases, there is a chance of malicious code injection. This paper discusses the threats with current WAP protocol, and how changes in the protocol and the increase in its usage will enable entry of real viruses. Future threat scenarios are presented along with suggestions to avoid these problems.展开更多
This research investigates a monopole patch antenna for Wi-Fi applications at 2.45 and 5.2 GHz,and WiMax at 3.5 GHz.A low-cost and flexible graphite sheet with good conductivity,base on graphite conductive powder and ...This research investigates a monopole patch antenna for Wi-Fi applications at 2.45 and 5.2 GHz,and WiMax at 3.5 GHz.A low-cost and flexible graphite sheet with good conductivity,base on graphite conductive powder and glue is used to create a radiator patch and ground plane.Instead of commercially available conductive inks or graphite sheets,we use our selfproduced graphite liquid to create the graphite sheet because it is easy to produce and inexpensive.The antenna structure is formed using a low-cost and easy hand-screen printing approach that involved placing graphite liquid on a bendable polyester substrate.This research focuses on designing and developing a low-cost,thin,light,and flexible patch antenna for wireless communication and smart glass applications.The proposed antenna utilizes CST microwave software for simulations to improve the parameters before fabrication and measurement.The simulation and measurement results for the reflection coefficients at 2.45 GHz,3.5 GHz,and 5.20 GHz are reliable and cover the required resonance frequencies,antennas gain are 1.91,1.98,and 1.87 dB,respectively.Additionally,the radiation patterns of both results are omnidirectional.In the experiments,bending the proposed patch antenna along with the cylinder with the radii of 60,40,and 25 mm yielded the same measurement results as the unbent patch antenna.展开更多
When computers and communication devices are available everywhere in the future, the categories of communication will expand to cover not only the man-man and the man-machine, but also the machine-machine (M2M) commun...When computers and communication devices are available everywhere in the future, the categories of communication will expand to cover not only the man-man and the man-machine, but also the machine-machine (M2M) communication. Someday, the traffic generated by machines will greatly exceed those of man-machine and man-man applications. Large numbers of M2M applications will need various wireless networks to support them. This paper introduces the characteristics, advantages and disadvantages of the currently available various wireless network technologies, including WiFi, Bluetooth, ZigBee, passive RFID and the 802.15 standard networks.展开更多
Wireless Sensor Network (WSN) is characterized by the dense deployment of sensor nodes that continuously observe physical phenomenon. The main advantages of WSN include its low cost, rapid deployment, self-organizat...Wireless Sensor Network (WSN) is characterized by the dense deployment of sensor nodes that continuously observe physical phenomenon. The main advantages of WSN include its low cost, rapid deployment, self-organization, and fault tolerance. WSN has received tremendous interests of various research communities,展开更多
Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless...Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.展开更多
With the rapid development and wide deployment of wireless technology, Wi-Fi signals have no longer been confined to the Internet as a communication medium. Wi-Fi signals will be modulated again by human actions when ...With the rapid development and wide deployment of wireless technology, Wi-Fi signals have no longer been confined to the Internet as a communication medium. Wi-Fi signals will be modulated again by human actions when propagating indoors, carrying rich human body state information. Therefore, a novel wireless sensing technology is gradually emerging that can realize gesture recognition, human daily activity detection, identification,indoor localization and human body tracking, vital signs detection, imaging, and emotional recognition by extracting effective feature information about human actions from Wi-Fi signals. Researchers mainly use channel state information or frequency modulated carrier wave in their current implementation schemes of wireless sensing technology, called "Walls have eyes", and these schemes cover radio-frequency technology, signal processing technology, and machine learning. These available wireless sensing systems can be used in many applications such as smart home, medical health care, search-and-rescue, security, and with the high precision and passively device-free through-wall detection function. This paper elaborates the research actuality and summarizes each system structure and the basic principles of various wireless sensing applications in detail. Meanwhile, two popular implementation schemes are analyzed. In addition, the future diversely application prospects of wireless sensing systems are presented.展开更多
文摘The wireless application protocol (WAP) protocol is now the leading standard for information services on wireless terminals like digital mobile phones. By the use of WAP, wireless devices, like mobile phones, are possibly infected with virus and worms. Though up to now there is no such attack, as the usage of script languages increases, there is a chance of malicious code injection. This paper discusses the threats with current WAP protocol, and how changes in the protocol and the increase in its usage will enable entry of real viruses. Future threat scenarios are presented along with suggestions to avoid these problems.
基金This work was supported by the RMUTT research and development fund。
文摘This research investigates a monopole patch antenna for Wi-Fi applications at 2.45 and 5.2 GHz,and WiMax at 3.5 GHz.A low-cost and flexible graphite sheet with good conductivity,base on graphite conductive powder and glue is used to create a radiator patch and ground plane.Instead of commercially available conductive inks or graphite sheets,we use our selfproduced graphite liquid to create the graphite sheet because it is easy to produce and inexpensive.The antenna structure is formed using a low-cost and easy hand-screen printing approach that involved placing graphite liquid on a bendable polyester substrate.This research focuses on designing and developing a low-cost,thin,light,and flexible patch antenna for wireless communication and smart glass applications.The proposed antenna utilizes CST microwave software for simulations to improve the parameters before fabrication and measurement.The simulation and measurement results for the reflection coefficients at 2.45 GHz,3.5 GHz,and 5.20 GHz are reliable and cover the required resonance frequencies,antennas gain are 1.91,1.98,and 1.87 dB,respectively.Additionally,the radiation patterns of both results are omnidirectional.In the experiments,bending the proposed patch antenna along with the cylinder with the radii of 60,40,and 25 mm yielded the same measurement results as the unbent patch antenna.
文摘When computers and communication devices are available everywhere in the future, the categories of communication will expand to cover not only the man-man and the man-machine, but also the machine-machine (M2M) communication. Someday, the traffic generated by machines will greatly exceed those of man-machine and man-man applications. Large numbers of M2M applications will need various wireless networks to support them. This paper introduces the characteristics, advantages and disadvantages of the currently available various wireless network technologies, including WiFi, Bluetooth, ZigBee, passive RFID and the 802.15 standard networks.
文摘Wireless Sensor Network (WSN) is characterized by the dense deployment of sensor nodes that continuously observe physical phenomenon. The main advantages of WSN include its low cost, rapid deployment, self-organization, and fault tolerance. WSN has received tremendous interests of various research communities,
文摘Distributed speech recognition (DSR) applications have certain QoS (Quality of service) requirements in terms of latency, packet loss rate, etc. To deliver quality guaranteed DSR application over wirelined or wireless links, some QoS mechanisms should be provided. We put forward a RTP/RSVP transmission scheme with DSR-specific payload and QoS parameters by modifying the present WAP protocol stack. The simulation result shows that this scheme will provide adequate network bandwidth to keep the real-time transport of DSR data over either wirelined or wireless channels.
基金supported in part by the National Natural Science Foundation of China under Key Program of NSFC (No. 61332019)NSFC (Nos. 61572304 and 61272056)Shanghai Key Laboratory of Specialty Fiber Optics and Optical Access Networks (No. SKLSFO2014-06)
文摘With the rapid development and wide deployment of wireless technology, Wi-Fi signals have no longer been confined to the Internet as a communication medium. Wi-Fi signals will be modulated again by human actions when propagating indoors, carrying rich human body state information. Therefore, a novel wireless sensing technology is gradually emerging that can realize gesture recognition, human daily activity detection, identification,indoor localization and human body tracking, vital signs detection, imaging, and emotional recognition by extracting effective feature information about human actions from Wi-Fi signals. Researchers mainly use channel state information or frequency modulated carrier wave in their current implementation schemes of wireless sensing technology, called "Walls have eyes", and these schemes cover radio-frequency technology, signal processing technology, and machine learning. These available wireless sensing systems can be used in many applications such as smart home, medical health care, search-and-rescue, security, and with the high precision and passively device-free through-wall detection function. This paper elaborates the research actuality and summarizes each system structure and the basic principles of various wireless sensing applications in detail. Meanwhile, two popular implementation schemes are analyzed. In addition, the future diversely application prospects of wireless sensing systems are presented.