Abstract: A distributed file system for devices is described. In an embodiment, each data element stored on one of the devices has an associated location and availability attribute. The location attribute is stored co-located with the data element. The availability attribute and a copy of the location attribute are stored by a metadata service. When a client on a device needs to access a data element, it sends a request to the metadata service to find the location of the data element. If the data element is available, this information is provided to the client and this may involve waking a dormant device which holds the data element. Where the data element is not available, read only access may be granted to a cached copy of the data element. Where replication is used and one of the devices holding a replica is unavailable, the system may use write off-loading.

Abstract: A distributed file system for devices is described. In an embodiment, each data element stored on one of the devices has an associated location and availability attribute. The location attribute is stored co-located with the data element. The availability attribute and a copy of the location attribute are stored by a metadata service. When a client on a device needs to access a data element, it sends a request to the metadata service to find the location of the data element. If the data element is available, this information is provided to the client and this may involve waking a dormant device which holds the data element. Where the data element is not available, read only access may be granted to a cached copy of the data element. Where replication is used and one of the devices holding a replica is unavailable, the system may use write off-loading.

Abstract: A distributed file system for devices is described. In an embodiment, each data element stored on one of the devices has an associated location and availability attribute. The location attribute is stored co-located with the data element. The availability attribute and a copy of the location attribute are stored by a metadata service. When a client on a device needs to access a data element, it sends a request to the metadata service to find the location of the data element. If the data element is available, this information is provided to the client and this may involve waking a dormant device which holds the data element. Where the data element is not available, read only access may be granted to a cached copy of the data element. Where replication is used and one of the devices holding a replica is unavailable, the system may use write off-loading.

Abstract: A distributed file system for devices is described. In an embodiment, each data element stored on one of the devices has an associated location and availability attribute. The location attribute is stored co-located with the data element. The availability attribute and a copy of the location attribute are stored by a metadata service. When a client on a device needs to access a data element, it sends a request to the metadata service to find the location of the data element. If the data element is available, this information is provided to the client and this may involve waking a dormant device which holds the data element. Where the data element is not available, read only access may be granted to a cached copy of the data element. Where replication is used and one of the devices holding a replica is unavailable, the system may use write off-loading.

Abstract: Wireless protocols in the unlicensed spectrum are developed for different requirements in terms of transmit range and power, which makes it difficult for multiple nodes having disparate transmit ranges to coexist in the same unlicensed spectrum. A short-range wireless node uses adaptive preambles to signal presence to long-range wireless nodes outside of its transmit range. In addition, a long-range wireless node detects an adapter preamble and backs-off transmissions for reservation period dedicated to short-range nodes.

Abstract: Wireless protocols in the unlicensed spectrum are developed for different requirements in terms of transmit range and power, which makes it difficult for multiple nodes having disparate transmit ranges to coexist in the same unlicensed spectrum. A short-range wireless node uses adaptive preambles to signal presence to long-range wireless nodes outside of its transmit range. In addition, a long-range wireless node detects an adapter preamble and backs-off transmissions for reservation period dedicated to short-range nodes.

Abstract: A distributed file system for devices is described. In an embodiment, each data element stored on one of the devices has an associated location and availability attribute. The location attribute is stored co-located with the data element. The availability attribute and a copy of the location attribute are stored by a metadata service. When a client on a device needs to access a data element, it sends a request to the metadata service to find the location of the data element. If the data element is available, this information is provided to the client and this may involve waking a dormant device which holds the data element. Where the data element is not available, read only access may be granted to a cached copy of the data element. Where replication is used and one of the devices holding a replica is unavailable, the system may use write off-loading.

Abstract: Methods, computer systems, and computer-storage media are provided for ranking ads. A reserve price is included in a calculation of a score to rank one or more advertisements for display. The calculation may further rely on a bid submitted by an advertiser for an advertisement, a click probability associated with the advertisement, a relevance of the advertisement to a search query and/or user, and the like. Once the reserve price is used to establish a score for one or more advertisements, a price is calculated for each of the one or more advertisements. The one or more advertisements may be displayed in an order indicated by the scores of each of the advertisements.

Abstract: Dynamic channel and transmission rate selection is described. In an example, a communication resource for transmitting data to a receiver is selected from several channels, each having several associated rates. The selection comprises storing a weighting factor for each channel/rate combination, monitoring transmission performance on a selected channel and rate, and inferring performance for other rates on the selected channel from the monitored performance. Each weighting factor is then updated using the monitored and inferred performances, and used to select a channel/rate combination for subsequent transmission. In another example, a communication device comprises a transmitter, a processor, and a memory arranged to store a weighting factor associated with each receiver, channel and rate combination.

Abstract: A data store including a file location attribute is described. In an embodiment, the location attribute for a data element, such as a file or database record, is stored with the bytes of data and records the geographic location of the data element. Writing to this attribute is limited to a single trusted entity, such as an operating system, to ensure that the location data can be trusted and when a data element is moved or replicated, the attribute is updated to reflect the new location of the data element. This location data is made available to users and applications by a metadata service which tracks the locations of data elements and responds to requests from users. Access control policies can been defined in terms of location and stored at the metadata service and the metadata service can then enforce these policies when responding to requests.

Abstract: Dynamic channel and transmission rate selection is described. In an example, a communication resource for transmitting data to a receiver is selected from several channels, each having several associated rates. The selection comprises storing a weighting factor for each channel/rate combination, monitoring transmission performance on a selected channel and rate, and inferring performance for other rates on the selected channel from the monitored performance. Each weighting factor is then updated using the monitored and inferred performances, and used to select a channel/rate combination for subsequent transmission. In another example, a communication device comprises a transmitter, a processor, and a memory arranged to store a weighting factor associated with each receiver, channel and rate combination.

Abstract: Wireless protocols in the unlicensed spectrum are developed for different requirements in terms of transmit range and power, which makes it difficult for multiple nodes having disparate transmit ranges to coexist in the same unlicensed spectrum. A short-range wireless node uses adaptive preambles to signal presence to long-range wireless nodes outside of its transmit range. In addition, a long-range wireless node detects an adapter preamble and backs-off transmissions for reservation period dedicated to short-range nodes.

Abstract: Wireless protocols in the unlicensed spectrum are developed for different requirements in terms of transmit range and power, which makes it difficult for multiple nodes having disparate transmit ranges to coexist in the same unlicensed spectrum. A short-range wireless node uses adaptive preambles to signal presence to long-range wireless nodes outside of its transmit range. In addition, a long-range wireless node detects an adapter preamble and backs-off transmissions for reservation period dedicated to short-range nodes.

Abstract: Systems, devices, and methods for associating network devices with users are described, which can facilitate establishing a secure user to network device association. In various embodiments, the disclosed subject matter facilitates devices providing indication of location and device identity to a user and recognizing the user is in the proximity of the device. The disclosed subject matter provides efficient and secure device to user association and can facilitate performing customized actions based on the nature of the association.

Abstract: A distributed file system for devices is described. In an embodiment, each data element stored on one of the devices has an associated location and availability attribute. The location attribute is stored co-located with the data element. The availability attribute and a copy of the location attribute are stored by a metadata service. When a client on a device needs to access a data element, it sends a request to the metadata service to find the location of the data element. If the data element is available, this information is provided to the client and this may involve waking a dormant device which holds the data element. Where the data element is not available, read only access may be granted to a cached copy of the data element. Where replication is used and one of the devices holding a replica is unavailable, the system may use write off-loading.

Abstract: A data store including a file location attribute is described. In an embodiment, the location attribute for a data element, such as a file or database record, is stored with the bytes of data and records the geographic location of the data element. Writing to this attribute is limited to a single trusted entity, such as an operating system, to ensure that the location data can be trusted and when a data element is moved or replicated, the attribute is updated to reflect the new location of the data element. This location data is made available to users and applications by a metadata service which tracks the locations of data elements and responds to requests from users. Access control policies can been defined in terms of location and stored at the metadata service and the metadata service can then enforce these policies when responding to requests.

Abstract: Dynamic channel and transmission rate selection is described. In an example, a communication resource for transmitting data to a receiver is selected from several channels, each having several associated rates. The selection comprises storing a weighting factor for each channel/rate combination, monitoring transmission performance on a selected channel and rate, and inferring performance for other rates on the selected channel from the monitored performance. Each weighting factor is then updated using the monitored and inferred performances, and used to select a channel/rate combination for subsequent transmission. In another example, a communication device comprises a transmitter, a processor, and a memory arranged to store a weighting factor associated with each receiver, channel and rate combination.

Abstract: Full-duplex wireless communication is described. In an embodiment, a transceiver device having a transmitter circuit and a receiver circuit receives a data packet sent over a shared communication medium. In the embodiment, the transceiver reads the header of the data packet and starts transmitting an output signal on the same shared communication medium. Embodiments are described in which, whilst the transmission of the output signal is ongoing, the transceiver receives an impaired data signal which is made up of the payload of the data packet and interference from the output signal. In the embodiment, a cancellation signal is derived from the output signal, and this is combined with the impaired data signal to remove the interference and recover the payload of the data packet.

Abstract: Full-duplex wireless communication is described. In an embodiment, a transceiver device having a transmitter circuit and a receiver circuit receives a data packet sent over a shared communication medium. In the embodiment, the transceiver reads the header of the data packet and starts transmitting an output signal on the same shared communication medium. Embodiments are described in which, whilst the transmission of the output signal is ongoing, the transceiver receives an impaired data signal which is made up of the payload of the data packet and interference from the output signal. In the embodiment, a cancellation signal is derived from the output signal, and this is combined with the impaired data signal to remove the interference and recover the payload of the data packet.

Abstract: Systems, devices, and methods for associating network devices with users are described, which can facilitate establishing a secure user to network device association. In various embodiments, the disclosed subject matter facilitates devices providing indication of location and device identity to a user and recognizing the user is in the proximity of the device. The disclosed subject matter provides efficient and secure device to user association and can facilitate performing customized actions based on the nature of the association.