Microsoft Technology Licensing, LLC

Alain Gefflaut

Arsalan Ahmad

Laurent Bussard

Petri H Mähönen

Ulrich Müller

Zhou Wang

Andreas Steinmetzler

Todd R Manion

Sandeep Singhal

Eldar Akchurin

Alexandre De Baynast

Frank Siegemund

Matthias Neugebauer

The disclosure describes a method for programming applications for embedded systems such as sensor nodes. In an embodiment, this comprises writing embedded system applications in a high-level language such as C# or Java using a software development framework which includes a set of tools and class libraries. The class libraries contain pre-written code to carry out tasks which may be required of an embedded system. The class libraries may be extended following identification of a need for a particular function in an embedded system. Developed applications may be subsequently stored on the embedded system but executed on a gateway computing device which interacts with the embedded system. This means that the application(s) can be executed without requiring the presence of a virtual execution system located on the embedded system while allowing a high-level programming model for application programmers.

Framework for programming embedded system applications

Methods for ad-hoc trust establishment using visual verification are described. In a first embodiment, a visual representation of a shared data is generated on two or more devices and the visual representations generated can be visually compared by a user. This method can be used to verify that the correct devices are involved in a negotiation, when pre-existing trust relationships do not exist between the devices. The visual representation may, for example, comprise a picture with a number of different elements, each representing a part of the shared data. In another embodiment, a method of secure key exchange is described in which, before sharing the keys, the parties exchange information which encapsulates the key. This information can be used subsequently to check that a party has not changed the key that they are using and prevents a man in the middle attack.

Ad-hoc trust establishment using visual verification

Cognitive radio adaptation is employed in WSNs to reduce effects of RF interference. Communication channel quality is assessed locally at each node. Using beacons to propagate channel quality and node related information among the nodes of the network, channel adaptation decision is made either centrally by identifying a channel that is optimum for a majority of nodes through a tree-structure dissemination (Majority Voting Scheme) or in a distributed manner by identifying a channel where maximum interference for any node is less than maximum interference on the other channels (Veto Voting Scheme). If two channels have the same level of maximal interference, the channel with a lesser number is chosen. Channel quality assessment may be optimized based on expected interference type and/or statistical methods.

Cognitive channel adaptation in wireless sensor networks

Architecture for exposing a virtual private network of peer devices into the public domain via an overlay network. Computing devices, peripheral devices, as well as mobile devices can be physically distributed, but appear to belong to the same virtual private (or home) network, and be accessible from anywhere. Benefits include access to user media/documents from anywhere, searching of all connected devices from one location, multicast and broadcast connectivity, management of the private network and the associated policies, and device discovery on the private network from across public networks. P2P networks and ad-hoc networks can be exposed as a virtual interface, as well as the utilization of client operating systems to create the virtual network, grouping, graphing, the integration with relay services and other NAT/firewall traversal schemes, and the creation of a P2P overlay manager on a physical NIC (network interface card) address rather than a virtual address.

Private virtual LAN spanning a public network for connection of arbitrary hosts

Methods and apparatus for device virtualization and for communication between network devices are described. In one example, all devices on a first Local Area Network (LAN) which are to communicate with devices on a second Local Area Network (LAN) have a virtual presence on LAN, and all the devices on LANwhich are to communicate with devices on LANhave a virtual presence on LAN, enabling these devices to communicate as if they were located in the same LAN. In another example, a device which uses different networking protocols to other devices on a network is virtualized on its own network, along with all the devices with which it communicates. In either example, the proposed virtualization technique may ensure that virtualized devices appear like physical devices to the other devices such that no modifications of the networking protocol is necessary to interact with a virtualized device.

Device virtualization

The disclosure describes a system for active channel management in a wireless network. The system may include spectrum monitoring in order to determine channel usage within a wireless network and/or to provide a projected transmission quality for each available channel. Another aspect of the system concerns allowing nodes in a wireless network to exchange spectrum usage data. The system may include renegotiation and handover of data transmission between channels and/or different wireless technologies.

Management of a wireless network

A framework capable of providing transparent handling of network traffic in close proximity networks such as home networks is provided. A single virtual network interface is exposed to users/applications on connected devices. A virtual network interface manager determines available physical network interfaces and switches to a different physical network interface or a different configuration on the same physical network interface in a transparent manner to the communicating application(s). This enables the framework to optimize network communications for the communicating applications, devices, and users based on predefined criteria, application requirements such as different data throughput, or changing environment conditions such as interference. Network communication operations are also simplified for users since they are no longer required to have the necessary knowledge for configuring physical network interfaces manually in response to changing conditions.

Framework for optimizing and simplifying network communication in close proximity networks

A method and system for determining the bit-rate between a wireless station and one or more access points that takes into account the usage (congestion) of the access points. Each wireless station includes software and/or hardware for estimating the bit-rate between the wireless station and any available access points and provides automatic load balancing for the wireless network. Dual estimator and backpressure algorithms are utilized to better estimate the achievable bit-rate available to a wireless station associated with an access point and to provide congestion sensitive access point selection. Bandwidth estimation is provided while taking into account congestion information for building up associations to access points while automatically achieving load balancing of the traffic among available access points.

Congestion level and signal quality based estimator for bit-rate and automated load balancing for WLANS

Provided is ad-hoc creation of groups based on contextual information comprising. Two mechanisms are used to restrict valid members of a group. First, to make sure that devices are somehow related, devices provide contextual information that is compared to the contextual information provided by other devices willing to join the group. Only devices providing 'similar' contextual information are accepted as possible candidates in the group. Second, to scope the group, a time window is used to limit the duration of the group creation. In other words, access to the group is reserved to the devices that can provide similar context information to existing member of the group in a defined time window. Security properties are ensured by enabling a visual check of the list of group participants. For instance, a member can verify that the displayed pictures indeed represent the attendees of an ongoing meeting.

Ad-hoc creation of group based on contextual information

A maximum achievable bit rate estimation for the expected bit rate between a wireless client and an access point is calculated in two phases. In the first phase, the maximum achievable bit rate is estimated using signal quality information and optionally congestion level information of the access point(s) of interest. In a second phase of the bit rate estimation, the first phase estimator output is corrected by using historical information relating the estimated bit rate values to the bit rates actually experienced. In the second phase of the estimation, a repository stores known signal quality behavior of the access points so as to provide an Access Point History (APH). The APH can be implemented as a simple memory (database) entity where a record is maintained on how accurate the previous bit-rate estimations turned out to be in practice. The actual physical embodiment of APH memory is implemented using any adequate memory technology such as FLASH, local hard disk, and the like. The APH is an ordered list where Access Point ID (SSID) and MAC address are combined with the data in an experimentally known relation between the SNR and the stable throughput. This two phase technique thus provides the implicit capability to include a rough bias to throughput estimation by congestion level of the access point as well as by historical bit rate averages.

Growing community of inventors

Herzogenrath, Germany

Alain Gefflaut