Paramvir Bahl

Bio: Paramvir Bahl is an academic researcher from Microsoft. The author has contributed to research in topics: Wireless network & Communication channel. The author has an hindex of 38, co-authored 127 publications receiving 4704 citations.

Fault detection and diagnosis

Abstract: A network troubleshooting framework is described. In an implementation, a method includes detecting discrepancy in operation of a network by supplying data that describes the network to a network simulation so that the network simulation provides an estimation of network performance. A determination is made as to whether the estimation of network performance differs from observed network performance of the network. A root cause of the discrepancy is diagnosed by injecting one or more of a plurality of faults into the network simulation until the estimation of network performance approximates the observed network performance.

Systems and methods for locating mobile computer users in a wireless network

Abstract: System and methods for locating a computer user are described wherein the computer either periodically updates a network server with its location, or updates the network server when asked by the server to do so. The network server can be a mobile computer. The user's computer determines its physical location using a location tracker service and then transmits this location information to the server, which stores it in its memory. The information stored includes the physical location of the computer, the time when the location was identified, a name identifying the user of the computer, and an indicator, which indicates whether or not the user was active on the computer during a specified time interval prior to the transmission. The location of the user is deemed to be the last known location of the computer used by the user. If the user is logged onto more than one computer, the location of the user is deemed to be the last known location of the computer that indicates the user as being active.

Selecting a wireless networking technology on a device capable of carrying out wireless network communications via multiple wireless technologies

Abstract: Criteria-driven methods and a framework are disclosed that facilitate configuration/selection of one or more wireless network interfaces/networks for carrying out wireless communications on a computing device The wireless network interface selection and coexistence driver architecture described herein facilitates automated selection of a particular mode of network access based upon status information provided by a set of network interface drivers associated with particular network interfaces and wireless technologies Furthermore, a criteria-driven interface/network selection framework is described that is potentially invoked in a variety of situations including, but not limited to, when an application is invoked or to select another interface/network to avoid detected interference

Methods and systems for providing variable rates of service for accessing networks, methods and systems for accessing the internet

Abstract: Systems and methods for providing network access, e.g. Internet access, are described. An architecture includes a host organization network through which network access is provided. The host organization network can be advantageously deployed in public areas such as airports and shopping malls. An authentication/negotiation component is provided for authenticating various users and negotiating for services with service providers on behalf of the system users. The authentication/negotiation component can include one or more specialized servers and a policy manager that contains policies that govern user access to the Internet. An authentication database is provided and authenticates various users of the system. An access module is provided through which individual client computing devices can access the Internet. In one embodiment, the access module comprises individual wireless access points that permit the client computing devices to wirelessly communicate data packets that are intended for the Internet. In one aspect, users are given a variety of choices of different service levels that they can use for accessing the Internet. The service levels can vary in such things as bandwidth allocation and security measures. The various service levels can be purchased by the users using their computing devices.

System and method for concurrent operation of a wireless device in two disjoint wireless networks

Abstract: A system and method for wireless network communications provides a “dual-mode” wireless device that operates concurrently as a member of two disjoint wireless networks, such as an infrastructure (“IS”) network and an ad hoc (“AH”) network. The dual-mode device has a wireless controller driver inserted in its networking stack (e.g., the stack comprising of the Network and NDIS drivers) that exposes two virtual wireless network adapters, one for the first wireless network and one for the second wireless network. Each virtual wireless network adapter has an associated queue for queuing packets in the flow for the corresponding wireless network mode. The wireless controller driver controls the switching of the network mode. In one embodiment where the two networks include an IS network and an AH network, the mode switching is triggered by poll signals transmitted by an access point of the IS network. When the mode is switched from operating in the first network to operating in the second network, the first virtual network adapter is disabled and the second virtual network adapter is enabled, and the queued packets in the queue for the second virtual network adapter are transmitted over the second wireless network.

Display screen or portion thereof with graphical user interface

Abstract: Newness and distinctiveness is claimed in the features of ornamentation as shown inside the broken line circle in the accompanying representation.

Proximity detector in handheld device

Abstract: Proximity based systems and methods that are implemented on an electronic device are disclosed. The method includes sensing an object spaced away and in close proximity to the electronic device. The method also includes performing an action in the electronic device when an object is sensed.

Indoor localization without the pain

Abstract: While WiFi-based indoor localization is attractive, the need for a significant degree of pre-deployment effort is a key challenge. In this paper, we ask the question: can we perform indoor localization with no pre-deployment effort? Our setting is an indoor space, such as an office building or a mall, with WiFi coverage but where we do not assume knowledge of the physical layout, including the placement of the APs. Users carrying WiFi-enabled devices such as smartphones traverse this space in normal course. The mobile devices record Received Signal Strength (RSS) measurements corresponding to APs in their view at various (unknown) locations and report these to a localization server. Occasionally, a mobile device will also obtain and report a location fix, say by obtaining a GPS lock at the entrance or near a window. The centerpiece of our work is the EZ Localization algorithm, which runs on the localization server. The key intuition is that all of the observations reported to the server, even the many from unknown locations, are constrained by the physics of wireless propagation. EZ models these constraints and then uses a genetic algorithm to solve them. The results from our deployment in two different buildings are promising. Despite the absence of any explicit pre-deployment calibration, EZ yields a median localization error of 2m and 7m, respectively, in a small building and a large building, which is only somewhat worse than the 0.7m and 4m yielded by the best-performing but calibration-intensive Horus scheme [29] from prior work.

Administration of protection of data accessible by a mobile device

Abstract: The protection of data on a client mobile computing device by a server computer system such as within an enterprise network or on a separate mobile computing device is described. Security tools are described that provide different security policies to be enforced based on a location associated with a network environment in which a mobile device is operating. Methods for detecting the location of the mobile device are described. Additionally, the security tools may also provide for enforcing different policies based on security features. Examples of security features include the type of connection, wired or wireless, over which data is being transferred, the operation of anti-virus software, or the type of network adapter card. The different security policies provide enforcement mechanisms that may be tailored based upon the detected location and/or active security features associated with the mobile device. Examples of enforcement mechanisms are adaptive port blocking, file hiding and file encryption.