Abstract: Mobile device localization using audio signals is described. In an example, a mobile device is localized by receiving a first audio signal captured by a microphone located at the mobile device and a second audio signal captured from a further microphone. A correlation value between the first audio signal and second audio signal is computed, and this is used to determine whether the mobile device is in proximity to the further microphone. In one example, the mobile device can receive the audio signals from the further microphone and calculate the correlation value. In another example, a server can receive the audio signals from the mobile device and the further microphone and calculate the correlation value. In examples, the further microphone can be a fixed microphone at a predetermined location, or the further microphone can be a microphone located in another mobile device.

Abstract: A decentralized relaying algorithm for mobile devices is described. In an embodiment, a mobile device acts as a relay within a network of mobile devices and on contact with a source device downloads messages from the source according to a locally stored relaying probability for each channel of information within the network. These messages are subsequently downloaded to another device which is the end user of the message. Where the relay does not download the message from the source as a result of the decision made based on the relaying probability, a virtual message is downloaded which comprises metadata only and not the payload of the message. The relay updates the stored relaying probabilities for each channel based on locally observable information which includes feedback received from mobile devices to which the relay has downloaded messages. The feedback identifies unique paths for the payload of messages through the network.

Abstract: Mobile device localization using audio signals is described. In an example, a mobile device is localized by receiving a first audio signal captured by a microphone located at the mobile device and a second audio signal captured from a further microphone. A correlation value between the first audio signal and second audio signal is computed, and this is used to determine whether the mobile device is in proximity to the further microphone. In one example, the mobile device can receive the audio signals from the further microphone and calculate the correlation value. In another example, a server can receive the audio signals from the mobile device and the further microphone and calculate the correlation value. In examples, the further microphone can be a fixed microphone at a predetermined location, or the further microphone can be a microphone located in another mobile device.

Abstract: Control of background data transfers is described. In an embodiment, a background data transfer is controlled at a receiver node by measuring a time period taken to receive from a sender node a data sequence of the same size as a receive window. The time period is used to evaluate available network capacity, and the network capacity used to calculate a new window size. The new window size is applied and communicated to the sender node. In another embodiment, a background data transfer is controlled at a receiver node by measuring a quantity of data received from a sender node during a first control interval. The measured quantity is used to evaluate available network capacity, and the network capacity used to calculate a new receive window size and a second control interval duration. The new window size is applied for the second control interval, and communicated to the sender node.

Abstract: A decentralized relaying algorithm for mobile devices is described. In an embodiment, a mobile device acts as a relay within a network of mobile devices and on contact with a source device downloads messages from the source according to a locally stored relaying probability for each channel of information within the network. These messages are subsequently downloaded to another device which is the end user of the message. Where the relay does not download the message from the source as a result of the decision made based on the relaying probability, a virtual message is downloaded which comprises metadata only and not the payload of the message. The relay updates the stored relaying probabilities for each channel based on locally observable information which includes feedback received from mobile devices to which the relay has downloaded messages. The feedback identifies unique paths for the payload of messages through the network.

Abstract: Mobile device localization using audio signals is described. In an example, a mobile device is localized by receiving a first audio signal captured by a microphone located at the mobile device and a second audio signal captured from a further microphone. A correlation value between the first audio signal and second audio signal is computed, and this is used to determine whether the mobile device is in proximity to the further microphone. In one example, the mobile device can receive the audio signals from the further microphone and calculate the correlation value. In another example, a server can receive the audio signals from the mobile device and the further microphone and calculate the correlation value. In examples, the further microphone can be a fixed microphone at a predetermined location, or the further microphone can be a microphone located in another mobile device.

Abstract: In example methods and algorithms, a node in a wireless mesh network calculates an estimated cost for a packet flow through the node. The estimation may be based on the back-log at the node and the cost of downstream neighbor nodes for the flow. Further, selection of a downstream flow and a downstream neighbor node may be based on the estimation. A packet re-ordering algorithm is also described which intercepts packets received at a node and delays delivery of the packet to the IP layer if an earlier packet in the sequence of packets has not been received.

Abstract: A method of transmitting data across a wireless mesh network is described which uses network coding at each of the intermediate nodes between the source node and the destination node. Each intermediate node also controls the rate at which it broadcasts packets based on link congestion and the backlog of packets at each of the possible next-hop nodes for the data flow.

Abstract: Control of background data transfers is described. In an embodiment, a background data transfer is controlled at a receiver node by measuring a time period taken to receive from a sender node a data sequence of the same size as a receive window. The time period is used to evaluate available network capacity, and the network capacity used to calculate a new window size. The new window size is applied and communicated to the sender node. In another embodiment, a background data transfer is controlled at a receiver node by measuring a quantity of data received from a sender node during a first control interval. The measured quantity is used to evaluate available network capacity, and the network capacity used to calculate a new receive window size and a second control interval duration. The new window size is applied for the second control interval, and communicated to the sender node.

Abstract: A method of ranking and suggesting objects, such as tags, is described in which a group of objects are suggested to a user in relation to a particular information object, such as a web page or file. A user either selects one of the suggestions or enters an alternative object and on receipt of data identifying the particular object selected by the user, the group of suggestions is updated based on whether the object selected by the user was one of the suggestions or not. The updating of the group may also be based on other factors, such as ranking parameters associated with each of the objects.

Abstract: Methods and algorithms for path estimation in a wireless mesh network are described. In an embodiment, each node calculates its cost for a packet flow based on the back-log at the node and the cost of downstream neighbor nodes for the flow. The cost is communicated to the upstream neighbor nodes for the flow. When a node has an opportunity to transmit a packet, a flow is selected by the node based on the back-log at the node and the costs received from each of the downstream neighbor nodes. These costs are then also used to select a downstream neighbor node is selected based on the costs received from each of the downstream neighbor nodes. A packet re-ordering algorithm is also described which intercepts packets received at a node and delays delivery of the packet to the IP layer if an earlier packet in the sequence of packets has not been received.

Abstract: An end-to-end congestion control is provided that emulates a different service differentiation than the common low-normal priority. This protocol is referred to as 4CP (Competitive, Considerate Congestion Control). The target service differentiation enables provisioning of per-flow average bandwidth guarantees to “normal” traffic, but not at the expense of potentially starving the “low” priority traffic (4CP). It thus features incentive compatibility to file-transfer applications that are throughput-greedy but want to be considerate to other traffic. 4CP is implemented and configured as a sender-only adaptation of standard TCP, and requires no special network feedback. Configuration of the bandwidth guarantee is either statically configured or automatically adjusted by 4CP. The automatic mode aims to be TCP-friendly over appropriately large timescale.

Abstract: Methods of enabling user-mode prototypes in kernel-mode protocol stacks are described. A protocol stack comprises a set of kernel-mode modules. The protocol stack defines a data path for packets. At least one interception point is defined in a kernel-mode module at which a packet can be intercepted and/or inserted. In an embodiment, each packet intercepted at the interception point, or a copy of said packet, is sent to a user-mode module. The user-mode module processes the packet in some way and then returns the packet to the same, or a different, interception point in the data path. In this way, a user-mode module (which is easier to program) can be used to prototype functionality of a kernel-mode module without requiring kernel-mode code to be written.

Abstract: A cost is determined for events related to the modification of system configuration parameter values in a computing device. If the cost meets or exceeds a threshold, a challenge is presented to a user of the computing device. If the user does not answer the challenge correctly, the system configuration parameters are reverted to their original values.

Abstract: In response to the occurrence of a restricted event in a computing device, a user of the computing device is presenting with a challenge including information designed to assist in determining whether the challenge is answered by a human. If it is determined that the challenge was not answered by a human, the restricted event is counteracted.

Abstract: A method of transmitting data across a wireless mesh network is described which uses network coding at each of the intermediate nodes between the source node and the destination node. Each intermediate node also controls the rate at which it broadcasts packets based on link congestion and the backlog of packets at each of the possible next-hop nodes for the data flow.

Abstract: A method of ranking and suggesting objects, such as tags, is described in which a group of objects are suggested to a user in relation to a particular information object, such as a web page or file. A user either selects one of the suggestions or enters an alternative object and on receipt of data identifying the particular object selected by the user, the group of suggestions is updated based on whether the object selected by the user was one of the suggestions or not. The updating of the group may also be based on other factors, such as ranking parameters associated with each of the objects.

Abstract: An end-to-end congestion control is provided that emulates a different service differentiation than the common low-normal priority. This protocol is referred to as 4CP (Competitive, Considerate Congestion Control). The target service differentiation enables provisioning of per-flow average bandwidth guarantees to “normal” traffic, but not at the expense of potentially starving the “low” priority traffic (4CP). It thus features incentive compatibility to file-transfer applications that are throughput-greedy but want to be considerate to other traffic. 4CP is implemented and configured as a sender-only adaptation of standard TCP, and requires no special network feedback. Configuration of the bandwidth guarantee is either statically configured or automatically adjusted by 4CP. The automatic mode aims to be TCP-friendly over appropriately large timescale.

Abstract: In response to the occurrence of a restricted event in a computing device, a user of the computing device is presenting with a challenge including information designed to assist in determining whether the challenge is answered by a human. If it is determined that the challenge was not answered by a human, the restricted event is counteracted.

Abstract: A cost is determined for events related to the modification of system configuration parameter values in a computing device. If the cost meets or exceeds a threshold, a challenge is presented to a user of the computing device. If the user does not answer the challenge correctly, the system configuration parameters are reverted to their original values.