Patent application number | Description | Published |
20110086664 | METHODS AND APPARATUS FOR SCALING TRANSMIT POWER OF SIGNALS IN WIRELESS COMMUNICATIONS - Methods and apparatus of varying transmit power of signals for increasing system throughput and spectral reuse in an unlicensed spectrum are disclosed. One method includes transmitting from a first mobile device to a second mobile device a request to send (RTS) signal having a first transmit data power level based on a channel gain between the first mobile device and the second mobile device, receiving, at the first mobile device, a clear to send (CTS) signal from the second mobile device, and transmitting data at the first transmit data power level from the first mobile device to the second mobile device. | 04-14-2011 |
20110149799 | METHODS AND APPARATUS FOR SUPPORTING MULTI-HOP PEER DISCOVERY IN PEER-TO-PEER WIRELESS NETWORKS - Methods and apparatus for supporting multi-hop peer discovery in peer-to-peer wireless networks are disclosed. One method supports multi-hop peer discovery using a first peer having a first unique identification code. The method includes decoding a second peer discovery signal to obtain a second unique identification code and a second local identification code of a second peer received during a peer-to-peer discovery channel, determining whether to select the second peer based on a predetermined criterion; and transmitting a first peer discovery signal having the first unique identification code, the second local identification code and a hop count when the predetermined criterion is satisfied. | 06-23-2011 |
20110207418 | METHODS AND APPARATUS FOR MEASURING AND/OR USING TRANSMITTER AND/OR RECEIVER IQ IMBALANCE INFORMATION AND/OR DC OFFSET INFORMATION - A wireless communications device, e.g., a mobile node supporting direct peer to peer communications, performs a self-calibration of one or more of: receiver IQ imbalance, transmitter IQ imbalance, receiver DC offset, and transmitter DC offset. The wireless communications device, operating in calibration mode, intentionally sets the oscillator frequency used for downconversion in its receiver module to a different frequency than the oscillator frequency used for upconversion in its transmitter module. A first baseband signal, e.g., a single tone test signal, is input to the transmitter module and an upconverted transmit signal is generated. The transmit signal is routed via a feedback loop to the receiver, which performs a downconversion operation. Power and/or phase measurements of the signals output from the downcoversion are used to determine IQ imbalance compensation information and DC offset compensation information. The determined compensation information is used subsequently when operating in a communications mode of operation. | 08-25-2011 |
20110222515 | METHODS AND APPARATUS FOR SUPPORTING SYNCHRONIZATION BETWEEN GROUPS OF DEVICES - Methods and apparatus related to supporting rapid synchronization between groups of wireless communications devices are described. Described methods and apparatus are well suited for use in peer to peer wireless communications systems in which a plurality of ad hoc peer to peer networks may be formed, each ad hoc network operating with its own notion of time. As two groups of devices, having different notions of time, come within proximity of one another, a wireless communications device of a first group detects the presence of a member of a second group. The wireless device determines that network timing re-synchronization is to be performed by one of the first and second groups and transmits a re-synchronization alert signal on a dedicated resource. Subsequently, the wireless device transmits a timing synchronization signal in accordance with new timing. Intended devices, which detect the alert signal and timing synchronization signal, adjust their internal timing. | 09-15-2011 |
20110249631 | METHODS AND APPARATUS FOR CHANNEL SELECTION IN A PEER TO PEER NETWORK - Various embodiments relate to using available spectrum for peer to peer communications and for selecting which of several possibly available channels should be used. Various methods and apparatus are well suited to peer to peer networks in which channel usage decisions are made in a decentralized manner. A wireless terminal generates a list of potential available channels to be used for peer to peer communications, e.g., based on FCC information and/or local sensing. Channels are filled in accordance with a predetermined channel ordering. A wireless terminal migrates between the channels in accordance with changes in the number of peer devices using a channel. The network, in a distributed manner, changes the number of channels in use at a location in response to changes in numbers of active peer devices at a location. | 10-13-2011 |
20110250916 | METHODS AND APPARATUS FOR DETERMINING AND ASSIGNING SPECTRUM FOR WIRELESS COMMUNICATIONS - Methods and apparatus for determining band availability and/or allocating one or more frequency bands to a communications device for wireless communications are described. In different locations and/or at different times different frequency bands, e.g., band corresponding to unused TV channels, may be available for allocation. Various described methods and apparatus are well suited for supporting local peer to peer networks in an environment in which a plurality of different technologies are supported. A centralized control device determines and allocates a frequency band to a wireless terminal for use at a given location and at a given time, e.g., for peer to peer communications using a particular technology supported by the wireless terminal. The centralized control device uses database information and information received from a plurality of wireless terminals in making frequency band allocation decisions, performing load balancing, and/or performing interference management. | 10-13-2011 |
20110274094 | METHODS AND APPARATUS FOR ESTIMATING A GEOLOCATION OF A WIRELESS COMMUNICATIONS DEVICE - The methods and apparatus described herein are used to perform indoor and urban geolocation positioning. One method of estimating a geolocation of one of a first wireless device or a second wireless device includes receiving, at the first wireless device, a signal from the second wireless device, determining, at the first wireless device, a physical characteristic of the received signal, and determining, at the first wireless device, a region on a map representing a geolocation of the first wireless device or the second wireless device based on the physical characteristic of the received signal, a state transition matrix and a state occupancy vector. | 11-10-2011 |
20110292884 | METHODS AND APPARATUS SUPPORTING LOAD BALANCING IN A WIRELESS COMMUNICATIONS SYSTEM - Methods and apparatus supporting load balancing in a wireless communications system implementing decentralized control are described. Different channels, e.g., unused TV channels, are available in different locations for use for communications. Various communications technologies, e.g., WiFi, 3G Blue-Tooth, etc., may be supported by a communications device and may be allowed to be used on the available channels. A wireless communications device evaluates its current local environment, e.g., estimating potential rates that it may use and/or estimating latency, for each of a plurality of available alternative channel/technology combinations. The wireless communications device selects a channel and technology combination to use as a function of its estimates. The wireless communications device uses its selected channel and technology combination for communications, e.g., for peer to peer communications including direct peer to peer traffic signaling as part of a local peer to peer network. | 12-01-2011 |
20120008618 | METHODS AND APPARATUS FOR TIMING SYNCHRONIZATION USING MULTIPLE DIFFERENT TIMING SIGNAL SOURCES - A wireless terminal detects timing signals from different local timing signal sources. The wireless terminal selects from the plurality of detected timing signal sources two timing signal sources in accordance with a predetermined timing signal source priority ordering. In some embodiments, the wireless terminal intentionally selects two timing signal sources which are not synchronized with respect to one another. The wireless terminal determines a first set of peer communications time intervals corresponding to a first selected timing signal source and a second set of peer communications time intervals corresponding to a second selected timing signal source. The wireless terminal transmits a peer to peer signal, e.g., a peer discovery signal, during at least one of the first set of peer communications time intervals. The wireless terminal transmits a peer to peer signal, e.g., a peer discovery signal, during at least one of the second set of peer communications time intervals. | 01-12-2012 |
20120014471 | METHODS AND APPARATUS FOR MINIMIZING INTER-SYMBOL INTERFERENCE IN A PEER-TO-PEER NETWORK BACKGROUND - The methods and apparatus described herein are used to operate a wireless device. One method of operating a wireless device includes filtering a first set of digital samples using a first filter at a first time to generate a first signal, transmitting the first signal, filtering a second set of digital samples using a second filter at a second time to generate a second signal, and transmitting the second signal. In one embodiment, an apparatus for operating a wireless device includes a processor configured to filter, at a first wireless device, a first set of digital samples using a first filter at a first time to generate a first signal, transmit, from the first wireless device, the first signal, and filter, at the first wireless device, a second set of digital samples using a second filter at a second time to generate a second signal. | 01-19-2012 |
20120020234 | METHODS AND APPARATUS FOR USE IN PEER TO PEER COMMUNICATIONS DEVICES AND/OR SYSTEMS RELATING TO RATE SCHEDULING, TRAFFIC SCHEDULING, RATE CONTROL, AND/OR POWER CONTROL - Methods and apparatus related to peer to peer communication networks are described. Embodiments directed to methods and apparatus for establishing traffic data transmission rates and/or transmission power levels between wireless terminals is described. Embodiments direct to methods and apparatus of making decisions whether or not to transmit as a function of the received power of the received response signals are also described. Transmission of pilot signals after granting of a transmission request and a decision to transmit traffic data has been made occurs in some embodiments. Rate information to be used in determining a traffic rate may be received in response to the pilot signal from a peer to peer (P2P) device. | 01-26-2012 |
20120056785 | METHODS AND APPARATUS FOR INCREASING THE RELIABILITY OF SIGNAL REFERENCE MAPS FOR USE IN POSITION DETERMINATION - A mobile wireless device receives a set of fingerprint prediction maps, e.g., RF signal prediction maps, and corresponding probability metrics, e.g., indicative of map reliability. A fingerprint prediction map is an expected signal measurement map corresponding to a parameter or parameters to be measured and a area given a set of expected conditions. At different times, e.g., due to different conditions, a different map in the set of fingerprint prediction maps may be more likely to be accurate. The mobile wireless device updates the probability metrics, associated with different alternative maps in the set of maps, as a function of one or more of: known information, sensor readings, measurements, detected information, and position determination. The mobile wireless device determines its current position using fingerprint predication maps and one or more updated probability metrics. | 03-08-2012 |
20120057646 | METHODS AND APPARATUS FOR ENCODING AND TRANSMITTING MOBILE DEVICE LOCATION INFORMATION - Methods and apparatus for communicating the location of a mobile wireless communications device are described. Codewords, e.g., values or sets of bits, are selected from a codebook mapping different codewords to corresponding pieces of location information. In a first approach location information is communicated by using codewords from different codebooks with the product, e.g., intersection of location information provided by the codewords, providing relatively detailed location information using relatively few bits. In a second approach user specific codebooks are defined for individual users. The codewords in the codebook corresponding to a particular user map to locations the individual specific user is likely to frequent. In another approach codewords are transmitted at different power levels and/or using different coding rates. Received codewords corresponding to a device may be used in combination to determine the location or refine the understanding of the device location. | 03-08-2012 |
20120058733 | METHODS AND APPARATUS FOR USING MOBILE DEVICES AS LOCATION ANCHOR POINTS - Mobile devices are used as temporary location anchor points, e.g., to supplement fixed location permanent location anchor points, in a wireless communications system in which mobile device locations are determined. A mobile device receives a command or request to operate as a location anchor point. In some embodiments, the command includes time information indicating the amount of time the mobile device is to operate as a location anchor point. In some embodiments, a mobile device operating as a location anchor point reports a received signal strength measurement along with information identifying the device from which the signal was received to a network element, e.g., a location server node. In some embodiments, a mobile device operating as a location anchor point broadcasts a signal providing location information. The mobile device receives compensation for operating as a location anchor point. Compensation may be monetary, services, or benefits provided by the network. | 03-08-2012 |
20120058745 | ADVERTISING METHODS AND APPARATUS FOR USE IN A WIRELESS COMMUNICATIONS SYSTEM - Methods and apparatus related to communicating advertisements and/or service announcements to devices in a communications system are described. In various embodiments mobile devices are used as mobile advertisement transmission platforms. Advertisements may be downloaded to the wireless communications device along with transmission constraints. Transmission of an advertisement is made when a transmission constraint, e.g., target audience constraint is satisfied. The wireless terminal may change its transmission frequency, coding rate and/or other transmission characteristics to satisfy a transmission constraint and/or optimize revenue. The mobile device reports advertisements transmissions to a network device, e.g., advertisement server and the owner of the device is compensated for the transmissions. Transmission constraints may involve a number of devices to be reached, the type of devices to be reached, and/or other constraints relating to the demographics of device users. Information may be obtained from peer discovery signals and used to determine if a constraint is satisfied. | 03-08-2012 |
20120182144 | METHODS AND APPARATUS FOR DISTRIBUTED LEARNING OF PARAMETERS OF A FINGERPRINT PREDICTION MAP MODEL - In accordance with various embodiments, mobile wireless devices which use prediction maps, e.g., RF prediction maps, to determine their location also contribute to the updating and distribution of parameters relating to prediction map generation. After a device determines its location, it uses the signal measurements used in determining the device's location to determine updated parameters which can be used in generating signal prediction maps in the future. The generated parameters are then transmitted to another device for use in generating prediction maps and/or distribution to other devices. In this manner parameters corresponding to a particular location can be updated and distributed without the need for a survey team and/or dedicated equipment. The devices using the prediction map become the devices which also aid in the updating of the parameters used to facilitate generation of a prediction map at some future time. In some embodiments, statistical information corresponding to the updated parameters is also generated and communicated. | 07-19-2012 |
20120184219 | METHOD AND APPARATUS FOR LEARNING OF THE PARAMETERS OF A FINGERPRINT PREDICTION MAP MODEL - Signal measurements are received, e.g., by a network device such as a location determination server, and a location of a mobile device to which the signal measurements correspond is determined. The measurements are also used to update parameters used to generate a signal prediction map. The signal prediction map, generated using the updated parameters, is then used for determining the position of another mobile device. In some embodiments parameter updating is performed when the location of a device is determined to a predetermined degree of certainty but not when the position of a mobile device is determined with a lower degree of certainty. Parameters used for generating prediction maps are updated, e.g., refined, based on signals collected for use in determining the location of a device without the need to conduct an updated survey and/or take signal measurements specifically for the purpose of updating prediction map parameters. | 07-19-2012 |
20120184286 | METHODS AND APPARATUS FOR MOBILE DEVICE LOCATION DETERMINATION - Methods and apparatus for resolving an ambiguity with regard to a mobile device's location are described. In various embodiments, when a level of ambiguity with regard to the location of a mobile device is detected, and the level of ambiguity is above a threshold, an ambiguity resolution request signal is generated and transmitted. In this manner, a wireless terminal needing help in determining its location reliably may request such help but at other times may determine its own location without assistance. In some embodiments the ambiguity resolution request signal includes information, e.g., location probabilities, on one or more locations which are under consideration as possible locations of the mobile device. A device responding to the ambiguity resolution request provides information allowing the mobile device confronted with a location ambiguity to eliminate at least on location under consideration or to generate a new probability for one or more locations under consideration. | 07-19-2012 |
20120184287 | METHODS AND APPARATUS FOR MOBILE DEVICE BASED LOCATION DETERMINATION IN A COMMUNICATIONS SYSTEM - Methods and apparatus related to determining location of mobile devices based on signals and/or location history information received from other mobile devices are described. In various embodiments mobile devices monitor signals from other devices. Mobile devices store signal measurement information along with time stamp information and information identifying the device from which a measured signal was received. In various embodiments a mobile communications device which determines its location with reasonable accuracy, e.g., to within a predetermined distance or some other accuracy metric, transmits location history information indicating one or more past locations, and optionally the device's current location, and the times it was at the indicated locations. Reliability information is communicated with the time and location information in some embodiments. A device receiving the location history log can determine and/or refine its understanding of its own location and the location of other devices at different points in time. | 07-19-2012 |
20120184301 | METHODS AND APPARATUS FOR DETERMINING MOBILE DEVICE LOCATION IN A COMMUNICATIONS SYSTEM - Methods and apparatus related to determining location of one or more mobile devices based on signals received by mobile device and signals received by fixed devices such as access points (APs) in a communications system are described. In accordance with various embodiments, mobile devices, e.g., peer devices, measure one or more signal characteristics, e.g., received signal power level, of signals received from peer devices and report this information along with information identifying the peer devices to which individual signal measurements correspond. The time of the signal measurements is also reported allowing a location determination server to time align signal measurements made by multiple different devices, e.g., mobile devices and access points, and use signals measurements from the multiple devices to determine the location of one or mobile devices, e.g., at one or more points in time, with more accuracy than if AP signal measurement alone were used. | 07-19-2012 |
20120249372 | METHODS AND APPARATUS FOR TRIGGERING COOPERATIVE POSITIONING OR LEARNING IN A WIRELESS NETWORK - One or more bits are used in peer discovery signals to signal a device's ability and/or willingness to participate in a cooperative manner with regard to one or more mobile device location determination related operations. In some embodiments, the one or more bits are located at predetermined locations within a header portion of a peer discovery signal. Different bits, in some embodiments, are associated with different specific cooperative location determination related operations. The peer discovery signal is transmitted, e.g., broadcast, periodically or on some predetermined basis by a mobile wireless communications device. In this manner, a device listening to the peer discovery signals can determine other devices' willingness to perform particular location discovery related operations with very little signaling overhead. | 10-04-2012 |
20120276863 | AUTOMATIC GAIN CONTROL IN A WIRELESS COMMUNICATION NETWORK - Techniques for performing automatic gain control (AGC) at a terminal in a wireless communication network are described. In an aspect, the terminal may use different receiver gain settings to receive different types of signals in different time intervals. The terminal may determine a receiver gain setting for each signal type and may use the receiver gain setting to receive signals of that signal type. In another aspect, the terminal may determine a receiver gain setting for a future time interval based on received power levels for peer terminals expected to transmit in that time interval. The terminal may measure received power levels of signals received from a plurality of terminals. The terminal may determine a set of terminals expected to transmit in the future time interval and may determine the receiver gain setting for the future time interval based on the measured received power levels. | 11-01-2012 |
20130065620 | METHOD AND APPARATUS FOR INCREASING THE RATE OF PEER DISCOVERY IN A SYNCHRONIZED PEER TO PEER WIRELESS NETWORK - Various methods and apparatus are directed to communicating peer discovery information in an efficient manner. A wireless device which has received peer discovery information from multiple peer devices in its vicinity combines received peer discovery information and transmits a signal communicating the combined information. In some embodiments, the combining includes performing a linear combination. The transmitted signal including the combined peer discovery information corresponding to multiple devices facilitates the recovery of peer discovery information by peer devices which may be out of direct peer to peer communications range to one of the devices whose information was used to produce the combined signal. Different peer devices may be able to recover different peer discovery information from the same combined signal. Thus the wireless device may effectively relay a first peer discovery message to one peer device and a second peer discovery message to another peer device via the same combined signal. | 03-14-2013 |
20130100947 | METHODS AND APPARATUS FOR TIMING SYNCHRONIZATION USING MULTIPLE DIFFERENT TIMING SIGNAL SOURCES - A wireless terminal detects timing signals from different local timing signal sources. The wireless terminal selects from the plurality of detected timing signal sources two timing signal sources in accordance with a predetermined timing signal source priority ordering. In some embodiments, the wireless terminal intentionally selects two timing signal sources which are not synchronized with respect to one another. The wireless terminal determines a first set of peer communications time intervals corresponding to a first selected timing signal source and a second set of peer communications time intervals corresponding to a second selected timing signal source. The wireless terminal transmits a peer to peer signal, e.g., a peer discovery signal, during at least one of the first set of peer communications time intervals. The wireless terminal transmits a peer to peer signal, e.g., a peer discovery signal, during at least one of the second set of peer communications time intervals. | 04-25-2013 |
20130150073 | METHODS AND APPARATUS FOR UPDATING INFORMATION USED IN GENERATING A SIGNAL PREDICTION MAP - A set of signal prediction map generation parameters, used to generate a signal prediction map to determine mobile device location, are initially modeled as large variance random variables. A network device, e.g., a server, receives estimated positions of mobiles and corresponding signal measurements, e.g., received signal power measurements, taken at those estimated positions by the mobiles. Received signal measurement information and corresponding estimated position information from a mobile is used to update one or more of the signal prediction map generation parameter distributions. After multiple updates to a distribution of a signal prediction map generation parameter, the network node transmits a prediction parameter update signal communicating the new distribution of the signal prediction parameter to be subsequently used by the mobile devices in the system when generating a signal prediction map and estimating its position. | 06-13-2013 |
20130183999 | METHOD AND APPARATUS FOR MULTI-RESOLUTION ADAPTIVE POSITIONING - Various embodiments are directed to methods and apparatus for mobile device position determination and the efficient communication of mobile device position related information. In different areas different types of reference signals may be available to be used by a mobile device for position determination. Some types of references signal may be well suited for short range in an indoor environment, e.g., audio signals, Bluetooth signals and Wi-Fi signals, while other types of signals may be well suited for an outdoor environment, e.g., GPS signals and cellular base station signals. Different types of signals may facilitate different possible resolution accuracies for a position determination. In various embodiments, in different areas within a geographic coverage region, different sets of reference signals are available to be used by a mobile wireless device to determine its position. In some embodiments, different position determination resolutions are used in different area as a function of the reference signal type which is available. | 07-18-2013 |
20130281142 | METHODS AND APPARATUS FOR CHANNEL SELECTION IN A PEER TO PEER NETWORK - Various embodiments relate to using available spectrum for peer to peer communications and for selecting which of several possibly available channels should be used. Various methods and apparatus are well suited to peer to peer networks in which channel usage decisions are made in a decentralized manner. A wireless terminal generates a list of potential available channels to be used for peer to peer communications, e.g., based on FCC information and/or local sensing. Channels are filled in accordance with a predetermined channel ordering. A wireless terminal migrates between the channels in accordance with changes in the number of peer devices using a channel. The network, in a distributed manner, changes the number of channels in use at a location in response to changes in numbers of active peer devices at a location. | 10-24-2013 |
20140006787 | METHOD AND APPARATUS FOR RESTRICTING ACCESS TO A WIRELESS SYSTEM | 01-02-2014 |
20140029471 | NETWORK-ASSISTED PEER DISCOVERY - Techniques for transmitting information in a long term evolution (LTE) wireless communication network are disclosed. A base station may receive a first user equipment (UE) expression and first UE location information of a UE seeking peers. The base station may also receive a second UE expression and second UE location information of at least one of the peers. In accordance with the first and second UE expressions and the first and second UE location information, the base station may match ones of the peers proximate to the UE. The base station may transmit, using a data exchange efficiency technique, information to alert the UE to the presence of the peers. This transmission may comprise wide area network (WAN)-specific signaling. | 01-30-2014 |
20140126911 | METHODS AND APPARATUS FOR COMMUNICATING INFORMATION USING VISIBLE LIGHT SIGNALS AND/OR RADIO SIGNALS - A user equipment (UE) device includes a VLC receiver including a photodiode and a radio receiver. The UE device supports a plurality of alternative technologies, communications protocols, and/or frequencies. During a first mode of operation, e.g., a discovery mode, a low reverse bias voltage value is applied to the photodiode. The low reverse bias voltage is adequate to support the recovery of small amounts of communicated information, and the power consumed by the battery of the UE device is relatively low. During discovery, information communicated includes, e.g., a light transmitter ID, an access point ID, services available at the access point, configuration information for a light receiver and/or for an auxiliary radio receiver. During a second mode of operation, e.g., a data traffic mode, the reverse bias voltage applied to the photodiode is set to a high reverse bias voltage to support higher data rate using VLC. | 05-08-2014 |
20140153923 | METHODS AND APPARATUS FOR COMMUNICATIONS USING VISIBLE LIGHT COMMUNICATIONS SIGNALING IN COMBINATION WITH WIRELESS RADIO SIGNALING - Various exemplary methods and apparatus are directed to using Visible Light Communication (VLC) in a downlink, e.g., a supplemental downlink, in combination with a wireless radio downlink/ uplink pair. A gateway is coupled, via a wireline link, to a VLC access point. In some embodiments, the gateway includes a wireless radio base station. A user equipment device detects a visible light signal from the VLC access point, and transmits a radio signal to a communications device, e.g., a gateway including a base station or a macro base station, indicating that the UE device is in a VLC coverage area. The gateway configures the VLC access point to serve as a supplemental wireless cell which supports downlink communications. The gateway sends traffic signals to the VLC access point, via the wireline, which are converted by the VLC access point into VLC signals which are transmitted. The UE device receives VLC downlink traffic signals and transmits a corresponding acknowledgment signal via an uplink radio channel. | 06-05-2014 |
20140241730 | METHOD AND APPARATUS FOR POWER-EFFICIENT JOINT DIMMING AND VISIBLE LIGHT COMMUNICATION - A method, an apparatus, and a computer program product for communication are provided. The apparatus obtains a message for communication using visible light communication (VLC) through a light emitting diode (LED) luminary device and formats the message using a synchronization signal followed by one or more data signals. The synchronization signal and/or the one or more data signals are modulated using a Frequency Shift Keying (FSK) modulation scheme. The apparatus further receives a dimming level value associated with a brightness of light to be emitted from the LED luminary device, generates a waveform with frequencies based on the formatted message and a duty cycle for the LED luminary device based on the dimming level value, and sends the generated waveform to the LED luminary device for communication using VLC. | 08-28-2014 |
20140255036 | METHODS AND APPARATUS FOR USING VISIBLE LIGHT COMMUNICATIONS FOR CONTROLLING ACCESS TO AN AREA - Methods and apparatus for controlling access to secure areas are described. Time varying values are generated from access device identifiers, e.g., door identifiers. The time varying value, e.g., a hashed door identifier value, is transmitted as a VLC signal by a luminaire near the door to which the hashed identifier corresponds. A mobile detects the transmitted hashed door identifier value and sends an access request via a wireless signal, e.g., a radio signal. The access request includes a value generated from the received hashed door identifier and a mobile device identifier. A control device determines, from information in the access request and stored information indicating which mobile devices have authority to access which doors, if access should be granted to the door corresponding to the hashed access device identifier from which the received information was generated. The received information may be hash of the mobile identifier and hashed door identifier. | 09-11-2014 |
20140270796 | METHOD AND APPARATUS OF DECODING LOW-RATE VISIBLE LIGHT COMMUNICATION SIGNALS - Methods and apparatus related to the detection of low-rate visible light communication (VLC) signals and the recovery of information communicated by the VLC signals are described. Various methods and apparatus are well suited for embodiments in which a device, e.g., a smartphone, including a camera which uses a rolling shutter. The rolling shutter facilitates the collection of different time snapshots of a received low rate time varying VLC signal with different pixel rows in the image sensor of a frame corresponding to different time snapshots. In some embodiments, demodulation is used to recover and identify a single tone being communicated in a frame from among a plurality of possible alternative tones that may be communicated, each different tone corresponding to a different set of information bits. | 09-18-2014 |
20140375982 | DETERMINATION OF POSITIONING INFORMATION OF A MOBILE DEVICE USING MODULATED LIGHT SIGNALS - Methods, systems, and devices are described for determining positioning information of a mobile device using modulated light signals. A modulated light signal may be received from each of at least one light source. Each modulated light signal may be decoded to obtain identification information identifying the at least one light source. An angle of arrival of each modulated light signal may also be identified. Each angle of arrival of may be associated with an identified light source. | 12-25-2014 |
20150036016 | METHODS AND APPARATUS FOR DETERMINING THE ORIENTATION OF A MOBILE PHONE IN AN INDOOR ENVIRONMENT - A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus captures one or more images of at least a first indicator and a second indicator, identifies the first indicator based on first identifying information and identifies the second indicator based on second identifying information, and determines an orientation of the mobile device based on the captured one or more images of the at least the first indicator and the second indicator. | 02-05-2015 |