Boingo Wireless is an American company that provides global Wi-Fi services.

When you connect an iPhone to a wi-fi network, the iPhone remembers that network and will automatically attempt to connect to it in the future. This is a great feature for wi-fi networks you trust and use frequently. But mistakes happen. If you connect to the wrong network at a coffee shop, your iPhone will automatically attempt to join that network every time you visit the coffee shop in the future. And if the password for a known network changes, your iPhone might have trouble connecting to it.

What's the solution? Telling your iPhone to forget the wi-fi network. Forgetting a network will remove the network's password and prevent your iPhone from joining it automatically in the future.

Here's how to tell your iPhone to forget a wireless network:

1. From the home screen, tap Settings.
   
   
2. Tap Wi-Fi. The window shown below appears.
   
   
3. Locate the wireless network you want the iPhone to forget, and then tap the blue arrow next to the network name. The window shown below appears.
   
   
4. Tap Forget this Network. The iPhone will forget the wireless network.

You have successfully told your iPhone to forget the wi-fi network. The iPhone will not attempt to connect to the network in the future. And if the network required a password, that password has been forgotten.

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Meet Your Macinstructor

Matt Cone, the author of Master Your Mac, has been a Mac user for over 20 years. A former ghost writer for some of Apple's most notable instructors, Cone founded Macinstruct in 1999, a site with OS X tutorials that boasts hundreds of thousands of unique visitors per month. You can email him at: matt@macinstruct.com.

Wireless sensor networks have attracted much attention because of many applications in the fields of industry, military, medicine, agriculture, and education. In addition, the vast majority of researches has been done to expand its applications and improve its efficiency. However, there are still many challenges for increasing the efficiency in different parts of this network. One of the most important parts is to improve the network lifetime in the wireless sensor network. Since the sensor nodes are generally powered by batteries, the most important issue to consider in these types of networks is to reduce the power consumption of the nodes in such a way as to increase the network lifetime to an acceptable level. The contribution of this paper is using topology control, the threshold for the remaining energy in nodes, and two of the meta-algorithms include SA (Simulated annealing) and VNS (Variable Neighbourhood Search) to increase the energy remaining in the sensors. Moreover, using a low-cost spanning tree, an appropriate connectivity control among nodes is created in the network in order to increase the network lifetime. The results of simulations show that the proposed method improves the sensor lifetime and reduces the energy consumed.

The increasing ubiquity of low-cost wireless sensors in smart homes and buildings has enabled users to easily deploy systems to remotely monitor and control their environments. However, this raises privacy concerns for third-party occupants, such as a hotel room guest who may be unaware of deployed clandestine sensors. Previous methods focused on specific modalities such as detecting cameras but do not provide a generalizable and comprehensive method to capture arbitrary sensors which may be "spying" on a user. In this work, we seek to determine whether one can walk in a room and detect any wireless sensor monitoring an individual. As such, we propose SnoopDog, a framework to not only detect wireless sensors that are actively monitoring a user, but also classify and localize each device. SnoopDog works by establishing causality between patterns in observable wireless traffic and a trusted sensor in the same space, e.g., an inertial measurement unit (IMU) that captures a user's movement. Once causality is established, SnoopDog performs packet inspection to inform the user about the monitoring device. Finally, SnoopDog localizes the clandestine device in a 2D plane using a novel trial-based localization technique. We evaluated SnoopDog across several devices and various modalities and were able to detect causality 96.6% percent of the time, classify suspicious devices with 100% accuracy, and localize devices to a sufficiently reduced sub-space.

A wireless communication system including a sender apparatus having a plurality of transmitting antennas that performs MIMO transmission of a plurality of data blocks; and a receiver apparatus that receives the plurality of data blocks. The sender apparatus transmits a process number via a control channel different from a data channel to the receiver apparatus, and wherein when the MIMO diversity transmission is performed, the receiver apparatus performs HARQ processing in the received data blocks based on not a process number which prevents the data blocks from competing but the received process number from the sender apparatus.

A method of generating a code sequence in a wireless communication system is disclosed. More specifically, the method includes recognizing a desired length of the code sequence, generating a code sequence having a length different from the desired length, and modifying the length of the generated code sequence to equal the desired length. Here, the step of modifying includes discarding at least one element of the generated code sequence or inserting at least one null element to the generated code sequence.

A method of interacting with data at a wireless communication device is provided. The wireless communication device has access to a first set of capabilities. Data is received at the wireless communication device via a wireless transmission. The data represents visual content that is viewable via a display device. A graphical user interface, including a delayed action selector, is provided via the display device. An input is received within a limited period of time after displaying the delayed action selector. The input is associated with a command to delay execution of an action with respect to the data until the wireless communication device has access to a second set of capabilities. The action is not supported by the first set of capabilities but is supported by the second set of capabilities. An indication of receipt of the input is provided at the wireless communication device.

The invention relates to compressed data transmission in wireless data communication. Disclosed are methods and apparatuses for transporting residue of vehicle position data via a wireless network. A disclosed method for transporting residue of vehicle position data via a wireless network, includes the steps of: receiving data for updating residue encoding schema from a monitoring server; constructing a residue encoding schema based on the data, thereby producing a constructed residue encoding schema; and storing the constructed residue encoding schema such that the constructed residue encoding schema will become the current residue encoding schema; where: the constructed residue encoding schema is constructed such that each residue of the constructed residue encoding schema corresponds to a code; and the constructed residue encoding schema is constructed such that a residue having a relatively high probability of occurrence corresponds to a code of relatively short length.

Vehicle event recorder systems are arranged to be in constant communication with remote servers and administrators via mobile wireless cellular networks. Vehicle event recorders equipped with video cameras capture video and other data records of important events relating to vehicle use. These data are then transmitted over special communications networks having very high coverage space but limited bandwidth. A vehicle may be operated over very large region while maintaining continuous communications connections with a remote fixed server. As such, systems of these inventions may be characterized as including a mobile unit having: a video camera; a microprocessor; memory; an event trigger; and mobile wireless transceivers, and a fixed network portion including: mobile wireless cellular network, a protocol translation gateway, the Internet and an application-specific server.

An apparatus and method control a connection between peripheral devices in a control server of a wireless communication system providing an IP-based communication service. The method for controlling the connection between peripheral devices includes registering at least one device in a group list classified by user identification information. The method also includes, if a control node including a user identifier of the group list requests a control of any one device included in the group list, checking an IP address of the device that is requested to be controlled by the control node. The method further includes sending a control command of the control node using the IP address.

The disclosure is directed to a system and method for establishing a secured wireless connection allowing the exchange of information between a wireless device and aircraft equipment. The secured wireless access system may require a user controlling the wireless device to interact with an onboard interface to initiate a connection. The user may be further required to enter a randomly generated security passcode to pair the mobile device to the aircraft equipment. Further security measures may be implemented, such as tiered user access levels restricting certain equipment and/or information based upon a user identity of the user requesting access.

A medical device, comprising first and second components coupled via a first wireless link; and a third component coupled to the first device via a second wireless link. The device implements a communication scheme in which transmissions via the second wireless link occur during a time period that is interleaved between periods including transmissions via the first link.

A wireless access system and, more particularly, a method and apparatus for more efficiently performing zone switch are disclosed. The method of performing zone switch by an advanced mobile station (AMS) in a mixed-mode advanced base station (ABS) which operates in a mixed mode of a broadband wireless access system includes receiving a ranging response (RNG-RSP) message including system information of an AMS support zone from a legacy zone (LZone) of the ABS, and performing ranging to the AMS support zone using the system information.

A method for operating a base station in a wireless communication system in order to support a plurality of characteristics is provided. The method includes allocating resource periods for respective characteristics, transmitting system information including information on the characteristics, transmitting a reference signal with the characteristic corresponding to the relevant resource period through at least one of the resource periods, and receiving feedback information determining channel qualities for all of the characteristics.

In general, to provide acknowledgment information by a first wireless device, the first wireless device sends repeated instances of acknowledgment information in respective first and second frame structures, in response to receipt of first information from a second wireless device. In addition, the first wireless device also sends further acknowledgment information in the second frame structure that is responsive to second information received from the second wireless device.

A mobile wireless communications device may include a portable housing, a circuit board carried by the portable housing, a wireless communications circuit carried by the circuit board, and an audio circuit carried by the circuit board. The mobile wireless communications device may further include an antenna assembly including an antenna carrier frame coupled to the circuit board and defining a cavity therein, and an antenna element carried on the antenna carrier frame and having a plurality of spaced apart signal feed points coupled to the wireless communications circuit. In addition, an audio transducer may be carried within the cavity of the antenna carrier frame and coupled to the audio circuit.

[Problem] To provide a wireless station, a determination apparatus, a wireless communication system, a determination method, and a storage medium which can carry out appropriate interference causing control in a secondary system adaptively to an actual environment with no change in a configuration of a primary system. [Means to solve the problem] A wireless station includes a determination means to determine at least one monitoring station measuring a wireless signal, which is transmitted by the wireless station and which causes interference to another system, out of plural wireless stations of a wireless communication system to which the wireless station belongs.

A wireless communication device is configured for performing uplink transmission power control. The wireless communication device includes a processor and instructions stored in memory. The wireless communication device performs uplink transmission power control for multiple regulated frequency bands or component carriers. The wireless communication device determines a total transmission power for at least one component carrier and allocates transmission power to at least one antenna.

Methods and apparatuses for acquiring/providing available channel information using Generic Advertisement Service (GAS) protocol in a wireless local area network (WLAN) are disclosed. AP (Access Point) station has a capability to acquire information for available channels from a database using a specific protocol related to an operation within the White Space (e.g. Access Network Query Protocol (ANQP)). And, non-AP station can retrieve the information for available channels by transmitting a Generic Advertisement Service (GAS) initial request frame to the AP station, wherein the GAS initial request frame comprises an Advertisement Protocol Element whose element ID indicates the specific protocol, and receiving a GAS initial response frame comprising a White Space Map (WSM) the specific protocol. The WSM comprises one or more white space channel units, and each of the white space channel units comprises a channel number field indicating one of the available channels and a power constraint field indicating a maximum allowable power on the indicated channel.

A method and system are provided for controlling uplink transmission power in a wireless communication system. At least one of a plurality of downlink carriers and a plurality of uplink carriers are aggregated, and the plurality of downlink carriers and the plurality of uplink carriers are mapped between a User Equipment (UE) and a network in the wireless communication system. A message relating to uplink carrier transmission power is received at the UE from the network via a downlink carrier. Uplink transmission power of one or more uplink carriers is controlled in accordance with the message and aggregation and mapping of at least one of the downlink carrier and the one or more uplink carriers.

Methods, systems, and devices are described for communicating physical layer wireless parameters over an application programming interface. A wireless modem of a wireless device may measure at least one physical layer wireless parameter. The wireless modem may report the at least one physical layer wireless parameter to an application running on the wireless device over an application programming interface between the wireless modem and the application. A behavior of the application may be adapted to control wireless communications between the application and a network based on the at least one physical layer wireless parameter reported by the wireless modem. Other aspects, embodiments, and features are also claimed and described.

In a wireless base station, a specific information receiver receives specific information delivered from a higher-level device to a wireless terminal. A specific information deliverer delivers the specific information to the wireless terminal via multiple physical channels activated in a wireless base station. Where a common channel via which information is periodically broadcast to multiple wireless terminals and a shared channel of which available radio resources are allocated to wireless terminals to transmit voice data and the like to the terminals are activated in the wireless base station, for example, the specific information deliverer can deliver the specific information using the common channel if the wireless terminal is in a standby state, and can deliver the specific information using the shared channel if the wireless terminal is in a communicating state.

A wireless communication system is provided that includes a wireless communication device in wireless communication with a base station and mobile stations. The wireless communication device includes first and second transceivers coupled to each other. The first transceiver is coupled to an antenna and is operable to communicate with the base station, which is also in wireless communication with other wireless communication devices. The second transceiver is coupled to another antenna and is in wireless communication with the plurality of mobile stations. The first transceiver receives a first signal from the base station intended for a one of the mobile stations, and in response the second transceiver transmits the first signal to the mobile station. The second transceiver receives a second signal from the mobile station intended for the base station, and in response the first transceiver transmits the second signal to the base station.

The invention concerns a method for optimizing antenna pattern assignment for a first wireless communication device forming a wireless network with at least one second wireless communication device, each of said communication device being equipped with a multi-sector antenna, an antenna pattern being a combination of said antenna sectors, said communication devices being adapted for sending a request and for receiving a response using a current antenna pattern assignment, said method comprising a step of: evaluating by said first communication device a first value;sending by said first communication device to said second communication device a broadcast request comprising said valuereceiving by said first communication device, a response to said broadcast request, said response being sent by said second communication device, said response depending on a second value evaluated by said second device;Switching or not, by said first communication device, to a new antenna sector assignment depending on said response; According to the invention the first value is evaluated by minimizing a first local function according to the received signal strength received by said first communication device having said current antenna pattern assignment and the second value is evaluated by minimizing a second local function according to the received signal strength received by said second communication device for its own current antenna pattern assignment.

The invention relates to a method for configuring a mobile device capable of reproducing, for a user, multimedia content previously provided by a remote content server. The invention relates to using a client installed on said electronic device to relay authentication requests between a card, preferably complying with the provisions of the Mobile Commerce Extension standard, and an authentication server that is accessible via an access point.

A system administrator of a wireless LAN 100 manipulates a personal computer PC1 to change a WEP key. The personal computer PC1 authenticates a memory card MC as genuine under management of the system administrator. In the case of the authenticated memory card MC, changed setting information, as well as a previous WEP key before the change of the setting information, is written into the memory card MC. The system administrator then inserts this memory card MC into a memory card slot of a printer PRT1. The printer PRT1 authenticates the memory card MC as genuine under management of the system administrator. In the case of the authenticated memory card MC, the setting information is updated. This arrangement effectively relieves the user's workload in setting wireless communication devices, while ensuring the sufficiently high security.

A secret stream of bits begins by receiving a public random stream contained in a wireless communication signal at a transmit/receive unit. The public random stream is sampled and specific bits are extracted according to a shared common secret. These extracted bits are used to create a longer secret stream. The shared common secret may be generated using JRNSO techniques, or provided to the transmit/receive units prior to the communication session. Alternatively, one of the transmit/receive unit is assumed to be more powerful than any potential eavesdropper. In this situation, the powerful transmit/receive unit may broadcast and store a public random stream. The weaker transmit/receive unit selects select random bits of the broadcast for creating a key. The weaker transmit/receive unit sends the powerful transmit/receive unit the selected bit numbers, and powerful transmit/receive unit uses the random numbers to produce the key created by the weaker transmit/receive unit.

A secret key generation apparatus and method are provided. The secret key generation apparatus includes at least one antenna, amplification/phase controllers, a transceiver, and a random signal controller. The antenna receives a wireless signal from a counterpart terminal that performs wireless communication. The amplification/phase controllers control the amplification gain and phase of the wireless signal that is received via at least one antenna. The transceiver measures the status of a wireless channel using the wireless signal having the controlled amplification gain and phase, determines parameters based on results of the measurement, and generates a secret key based on results of the determination. The random signal controller controls the amplification/phase controllers so that the amplification gain and phase are adjusted whenever the transceiver generates a secret key.

A method and a playback control device are provided. The method, performed by the playback control device, includes: receiving a first request to playback a first data of a first wireless multimedia data type having a first priority; and playing back the first data if no other data of a wireless multimedia data type having a priority higher than the first priority is received.

A wireless communication terminal includes a communication status measurement element for measuring communication status data representing a communication status of the self terminal at the time of wireless communications; a reference data storage element for storing respective pieces of preset reference data representing communication statuses of a terminal which can be measured at respective locations at the time of wireless communications, in association with respective pieces of location data identifying the respective locations, and a location specifying element for comparing the communication status data measured by the communication status measurement element with the respective pieces of reference data stored in the reference data storage element, and based on the comparison result, specifying a location corresponding to the location data associated with a particular piece of reference data as a location of the self terminal.

Techniques for determining time of arrivals (TOAs) of signals in a wireless communication network are described. Each cell may transmit (i) synchronization signals on a set of contiguous subcarriers in the center portion of the system bandwidth and (ii) reference signals on different sets of non-contiguous subcarriers distributed across the system bandwidth. A UE may determine TOA for a cell based on multiple signals transmitted on different sets of subcarriers. The UE may perform correlation for a first signal (e.g., a synchronization signal) from the cell to obtain first correlation results for different time offsets. The UE may perform correlation for a second signal (e.g., a reference signal) from the cell to obtain second correlation results for different time offsets. The UE may combine the first and second correlation results and may determine the TOA for the cell based on the combined correlation results.

Multi-pattern transmission of frames. The method of operations comprises transmitting a first portion of a frame using a first radiation pattern. The frame comprises one or more preambles and a single data portion associated with the one or more preambles. Thereafter, an operation is conducted to switch the radiation pattern from the first radiation pattern, used to produce the first portion of the frame, to a second radiation pattern. A second portion of the same frame is produced using the second radiation pattern.

Techniques for positioning access points and terminals in WLANs and other wireless networks are described. For access point positioning, measurements are obtained for at least one access point in a WLAN. The measurements may be based on transmission sequences (e.g., beacon frames) transmitted periodically by each access point. The measurements may be made by multiple terminals at different locations or a single mobile terminal at different locations. The location of each access point is determined based on the measurements and known locations of the terminal(s). For terminal positioning, measurements for at least one access point in a WLAN are obtained. The location of the terminal is determined based on the measurements and known location of each access point. The measurements may be round trip time (RTT) measurements, observed time difference (OTD) measurements, time of arrival (TOA) measurements, signal strength measurements, signal quality measurements, etc.

Described herein are improved configurations for a wireless power transfer involving photovoltaic panels. Described are methods and designs that use electric energy from a photovoltaic module to energize at least one wireless energy source to produce an oscillating magnetic field for wireless energy transfer. The source may be configured and tuned to present an impedance to a photovoltaic module wherein said impedance enables substantial extraction of energy from said photovoltaic module.

A wireless power feeder feeds power from a feeding coil L2 to a receiving coil L3 by wireless using a magnetic field coupling between the feeding coil L2 and the receiving coil L3. The feeding coil L2 is formed so as to be rotated. A power transmission control circuit supplies AC power to the feeding coil L2 to make the feeding coil L2 feed the AC power to the receiving coil L3. The power transmission control circuit rotates the feeding coil L2 to change the opposing area between the feeding coil L2 and the receiving coil L3 as viewed in the axis direction of the feeding coil L2 to thereby adjust the AC power to be supplied from the feeding coil L2 to the receiving coil L3.

A transmit pad inspection device includes a magnetic coupling device, which includes an inductive circuit that is configured to magnetically couple to a primary circuit of a charging device in a transmit pad through an alternating current (AC) magnetic field. The inductive circuit functions as a secondary circuit for a set of magnetically coupled coils. The magnetic coupling device further includes a rectification circuit, and includes a controllable load bank or is configured to be connected to an external controllable load back. The transmit pad inspection device is configured to determine the efficiency of power transfer under various coupling conditions. In addition, the transmit pad inspection device can be configured to measure residual magnetic field and the frequency of the input current, and to determine whether the charging device has been installed properly.

A wireless access device in a wireless network, whether a known or unknown entity, can be located using a geolocation system according to the present invention. A signal strength is determined by a wireless intrusion detection system (WIDS) node in a wireless network for each wireless access device that it detects. Based on the signal strength, an approximate distance from the node is determined, which, in one embodiment corresponds to a radius of a circle around the node. To account for error, an approximation band of the circle is calculated that will allow a user to determine the approximate location of the device within the wireless network.

The invention relates to a universal wireless trainable transceiver unit with integrated bidirectional wireless interface functionality, and a method for same. Using a scan, push button or untrained channel mode, a user may enter into a wireless bidirectional interface mode of a trainable transceiver. The interface mode allows a user to select a sub-set of modes that include diagnostics, flash and vehicle interface. Each mode provides the trainable transceiver to communicate wirelessly in a bidirectional manner with another remote device.

A wireless camera apparatus includes a power supply track and a wireless camera device detachably installed on the power supply track. The wireless camera device has a camera module and a linking module fixed on the camera module. The linking module has a connecting unit and a conductive unit electrically connected to the camera module. When the wireless camera device is installed on the power supply track, the connecting unit is coupled to the power supply track, and the conductive unit is electrically connected to the power supply track. Thus, the instant disclosure provides the wireless camera apparatus, which is adjustable to any position of the power supply track according to the user's demand. Besides, the instant disclosure further provides a wireless camera device.

Aspects and embodiments of the present invention provide a system for obtaining, processing and managing data from an implanted sensor. In some embodiments, a patient or other persons can use a flexible antenna to obtain data from the implanted sensor. The flexible antenna includes at least one transmit loop and at least one receive loop. The transmit loop is adapted to propagate energizing signals to the implanted sensor. The receive loop is adapted to detect a response signal from the implanted sensor. The transmit loop includes a capacitor formed by a discontinuous area. The capacitor is adapted to allow the loop to be tuned. The flexible antenna can communicate with a patient device that collects the data from the implanted sensor, creates a data file and transmits the data file to a remote server over a network. A physician or other authorized person may access the remote server using an access device.

Methods and apparatus for computing the carrier frequency of a transmitter using frequency modulated digital data to compensate for frequency shifting of the transmitter and the receiver local oscillators and for bandwidth adjustment of the receiver's filter. In particular, methods and apparatus are disclosed for binary systems transmitting “1” and “0” data using decoded or undecoded received signals.

An exemplary system for managing the deployment of a seismic data acquisition system uses a module configured to execute a plurality of task in the field by receiving one or more seismic devices. The module may include a power source that provides electrical power to the seismic devices. The module may also include a processor programmed to retrieve data stored in the seismic devices, perform diagnostics, facilitate inventory and logistics control, configure seismic devices and update data or pre-programmed instructions in the seismic device.

Next generation pervasive wireless ecosystems and mobile information apparatus are herein disclosed and enabling millions of users to migrate to pervasive digital living and enterprise. Wireless communications may include the mobile information apparatus accessing wireless local area network or by direct wireless communication. The mobile information apparatus may include a wireless unit compatible with Bluetooth and/or IEEE802.11. Mobile information apparatus may conduct a local area wireless search within short distances for discovering wireless devices in its vicinity, receive an attribute related to the discovered wireless device, establish secure wireless communication with the discovered wireless device, and transfer or synchronize digital content or applications to/from the discovered wireless device. The discovered wireless device may be other mobile apparatus, wireless televisions, wireless audio devices, wireless speakers, wireless printers, among others, in a digital living room or office. Mobile apparatus may be smart phones, information pads, or laptops with touch sensitive screen interface.

A transaction is preprocessed wirelessly in response to a wireless transaction preprocessing user device being in a queue for a point-of-transaction. The transaction that was preprocessed is then completed in response to the wireless transaction preprocessing user device reaching the point-of-transaction. Financial transactions and/or purchase of goods and/or services may thereby be preprocessed wirelessly and then completed at a point-of-transaction. Related devices and computer program products are also disclosed.

A method that utilizes software and hardware mechanisms to meet the FCC requirement for a U-NII antenna to be an integral part of the device in which it operates, while providing wireless ready U-NII devices and CRUable U-NII radios. Enhancements are made to the software BIOS, including the inclusion of a table of approved radio-antenna PCI ID pairs to create an authentication scheme that verifies and authenticates the radio and antenna combination as being an FCC-approved unique coupling during boot-up of the system. The BIOS also comprises an OEM field that stores an encrypted secret key utilized to complete a second check of the radio model placed in the device. During boot up of the device, the PCI ID pairs from the BIOS are compared against the PCI ID of the radio and the secret key is checked against the radio model. Only a system with an approved combination of radio and antenna is allowed to complete the boot process, indicating an FCC approved device-antenna-radio combination under the “integral” requirement.

A method of transmitting a training signal in a Wireless Local Area Network (WLAN) system includes generating one or more first training signals for a first destination station and one or more second training signals for a second destination station by applying a mapping matrix P to a training signal generation sequence, mapping the first training signals and the second training signals to a plurality of antennas according to an antenna mapping matrix, and performing Inverse Fast Fourier Transform (IFFT) on each of the first training signals and the second training signals mapped to the plurality of antennas and transmitting the training signals through the plurality of antennas.

In a wireless network, plural downlink signals from plural base stations are transmitted to a terminal. The plural downlink signals all carry the same information to the terminal. The terminal provides feedback on the downlink channels. The feedback provides information on the taps of the channels. The amount of information fed back is constrained. Based on the feedback, transmission parameters of the downlink signals are adjusted. The process of transmitting, providing feedback, and adjusting the parameters continue so that the energy of the downlink signal is enhanced at the terminal location and suppressed elsewhere. Beam forming can be used to further suppress the energy signature at locations other than the terminal location.

In order to transmit a large amount of data in series at a time with a MIMO communication scheme while avoiding deterioration of decoding characteristics due to change over time by a channel matrix, a wireless communication system uses an open-loop type and a closed-loop type of MIMO communication modes in combination and switches to the open-loop MIMO communication mode in response to the information that the amount of data to be transmitted at a time has exceeded a predetermined amount of bits or a predetermined transmission time during data transmission under the closed-loop MIMO communication mode. By discontinuing useless closed-loop MIMO communication and switching to the open-loop MIMO communication mode that is better than Zero-forcing, the decoding characteristics are prevented from simply becoming deteriorated.

A direct feeding apparatus for impedance matching of a wireless power transmission device includes a helical type resonator, and a feeding unit configured to directly feed power to a region having a relatively small current value as compared to a center of a conductive line of the resonator.

The invention relates to a monitoring system for monitoring a state of a door lock mechanism of a door or of a closure of a storage space of a means of transportation, comprising a generator and a sensor/actuator. The generator produces electrical energy from vibration energy, and the sensor detects the state of the door lock mechanism. The sensor uses the kinetic energy that is produced by the actuation of the door lock to generate an electrical signal, which is then transmitted to a microcontroller.