Pramita Mitra

Efficient group communications in location aware mobile ad-hoc networks

The highly dynamic and uncertain character of mobile ad-hoc networks poses significant challenges for group management. Node mobility often changes the multicast tree, and therefore, frequent updates from group members are required to refresh the multicast tree at the source node. This paper presents Courier, a group communications algorithm that uses the location and velocity of roaming nodes to provide bandwidth efficient multicast between a source and its destinations (i.e., group members) in location aware mobile environments. Toward that end, Courier offers (1) a bandwidth efficient method for location updates from group members, (2) a mobility prediction model for predicting the movement of mobile group members, and (3) an overlay multicast data distribution tree (OMDDT) construction algorithm that is guided by the mobility prediction model. Comparisons of Courier to related multicast algorithms indicate an increase in data transmission success and a decrease in overall bandwidth consumption.

Emergency response in smartphone-based Mobile Ad-Hoc Networks

Todays modern mobile devices (e.g., smartphones and tablets) present great potential for building large-scale mobile sensing and information sharing systems which can be highly beneficial to minimize the fatalities of human lives during emergency response. This paper presents a framework, called BREathing rate MONitoring (BREMON) that allows paramedics to monitor the breathing activities of multiple patients at once using their smartphones. BREMON uses the smartphone accelerometer to measure the accelerations during the breathing activities of a patient. These raw acceleration data are then processed to calculate the number of Breaths Per Minute (BPM) and periodically sent to the smartphones used by the paramedics over a multi-hop network. BREMON makes use of an underlying service sharing infrastructure, called SPontaneous Information and Resource sharing InfrasTructure (SPIRIT) that allows mobile devices to share the breathing activity data as services within the infrastructure.

Asymmetric Geographic Forwarding: Exploiting Link Asymmetry in Location Aware Routing

Geographic Forwarding GF algorithms typically employ a neighbor discovery method to maintain a neighborhood table that works well only if all wireless links are symmetric. Recent experimental research has revealed that the link conditions in realistic wireless networks vary significantly from the ideal disk model and a substantial percentage of links are asymmetric. Existing GF algorithms fail to consider asymmetric links in neighbor discovery and thus discount a significant number of potentially stable routes with good one-way reliability. This paper introduces Asymmetric Geographic Forwarding A-GF, which discovers asymmetric links in the network, evaluates them for stability e.g., based on mobility, and uses them to obtain more efficient and shorter routes. A-GF also successfully identifies transient asymmetric links and ignores them to further improve the routing efficiency. Comparisons of A-GF to the original GF algorithm and another related symmetric routing algorithm indicate a decrease in hop count and therefore latency and an increase in successful route establishments, with only a small increase in overhead.

On Improving Dynamic Source Routing for Intermittently Available Nodes in MANETs

Previous work on routing in MANETs has resulted in numerous routing protocols that aim at satisfying constraints such as minimum hop or low energy. Existing routing protocols often fail to discover stable routes between source and sink when route availability is transient, i.e., due to mobile devices switching their network cards into low-power sleep modes whenever no communication is taking place. In this paper, we introduce a stability aware dynamic source routing protocol (SA-DSR) that is capable of predicting the stability (i.e., expiration time) of multiple routes. SA-DSR then selects the route that minimizes hop count while staying available for the expected duration of packet transmission. Comparisons of SA-DSR to the original DSR (Dynamic Source Routing) protocol indicate a significant (up to 60%) increase in route discovery success rate with comparable route establishment and maintenance overheads.

Stability aware routing: exploiting transient route availability in MANETs

The highly dynamic character of a mobile ad-hoc network (MANET) poses significant challenges on network communications and resource management. Previous work on routing in MANETs has resulted in numerous routing protocols that aim at satisfying constraints such as minimum hop/distance or low energy. Existing routing protocols often fail to discover stable routes between source and sink when route availability is transient, e.g., due to mobile devices switching their network cards into low-power sleep modes whenever no communication is taking place. In this paper, we introduce a stability aware dynamic source routing protocol (SA-DSR) that is capable of predicting the stability (i.e., expiration time) of multiple routes. SA-DSR then selects the route that minimizes hop count while staying available for the expected duration of packet transmission. Comparisons of SA-DSR to the original DSR (Dynamic Source Routing) protocol indicate a significant (up to 31%) increase in successful packet transmissions with comparable route establishment and maintenance overheads.

Service sharing in mobile sensing systems

Todays modern mobile devices, (such as smart-phones and tablets) present great potential for growth of many novel, powerful, but also highly demanding applications. However, most mobile devices/users operate in isolation from one another, i.e., they are not aware of the presence of other devices in their proximity. There are numerous situations where proximity-awareness (i.e., a device is aware of other mobile devices in its neighborhood) could be used to support spontaneous sharing of resources and information, thereby enabling a variety of new application scenarios. This paper presents an architecture, called Spontaneous Information and Resource sharing InfrasTructure (SPIRIT), that allows mobile devices to create, discover, join, leave, and revoke the sharing of resources in an efficient and robust fashion. Built on top of a group communications layer for mobile devices, SPIRIT allows users or devices to express various heterogeneous services and service sharing paradigms using a novel subscription language. While the shared services can include various types of resources (e.g., network connections, CPU) and information (e.g., database entries), this papers focus is on sensor information, i.e., the information collected by the various sensors found in modern mobile devices (e.g., GPS, acceleration, light, pressure, sound, etc.).

Opportunistic Routing in Mobile Ad Hoc Networks

Routing in opportunistic mobile ad hoc networks (MANETs) is characterized by intermittent and sporadic communication opportunities between portable devices. As a result, a path between the source and the destination(s) may only exist for a brief and unpredictable period of time, thereby leading to network partition. Most existing routing approaches store data packets locally and forward them when in reach of a mobile peer that carries the data packets closer to the destination. Through a survey of recent literature, this chapter will provide an overview of the routing protocols that exploit intermittent communication opportunities for increased data transmission success in MANETs, and characterize them using the following three aspects: (1) how does the protocol discover and exploit the intermittent communication opportunities in a mobile environment? (2) How does the protocol address multicast, which is a common data dissemination pattern in an opportunistic communication environment? and (3) What kind of real-world applications are enabled by the use of opportunistic routing protocols?

Quality of Service Specifications in Small-Scale Proximity-Aware Mobile Sensor Sharing Frameworks

Proximity-awareness, that is, a mobile device being aware of the presence and capabilities of other devices in its proximity, can be beneficial in many frameworks that support spontaneous sharing of sensors available in advanced personal mobile devices (e.g., smartphones and tablets). Providing Quality of Service (QoS) guarantees in such frameworks is highly challenging because of the dynamic and loosely coupled nature of Mobile Ad Hoc Networks (MANETs). A framework called the SPontaneous Information and Resource sharing InfrasTructure (SPIRIT) has been presented before to address the challenges of proximity-aware mobile sensor sharing. SPIRIT allows mobile applications to share sensors as services in an automatic fashion by enabling the service providers and clients to express a variety of QoS specifications. This paper presents a set of mobility-aware QoS mechanisms for enabling the implementation of QoS specifications along the multihop paths between service providers and clients in highly mobile environments. Simulations in small-scale Mobile Ad Hoc Networks show SPIRIT’s ability to effectively control and manage traffic flows while maintaining desired QoS. The implications of the proposed QoS mechanisms extend beyond the scope of SPIRIT, as QoS provisioning is an important issue in many MANET frameworks and applications including Vehicular Ad Hoc Networks (VANETs).

A Novel Approach to the Design and Development of an Interactive Learning App for Automotive IVI Systems

Since its launch Ford SYNC™ with MyFord Touch™ in-vehicle infotainment (IVI) system has migrated to many vehicle programs and had multiple software updates, which presented Ford dealers with the ever-increasing challenge of training new owners effectively and efficiently. This paper presents the design, architecture and implementation of “MyFord Touch Guide”, a novel, cross-platform mobile app that delivers a unique MyFord Touch learning and familiarization experience for dealers and consumers alike. This app incorporates the production MyFord Touch graphical user interface for an interactive learning experience. Additionally, it integrates a host of video tutorials featuring a computer-animated character, which offers an insightful, personalized and self-guided tour experience of the essential features and functions of the system. MyFord Touch Guide is a cross-platform app and based on a “hybrid” app architecture that uses both native mobile and web technologies. Feedback gathered from multiple nation-wide surveys indicates that the proposed approach provides a highly effective and scalable solution towards developing a diverse range of cross-platform, interactive, mobile learning apps.Copyright

Concurrent FFT computing on multicore processors

The emergence of streaming multicore processors with multi‐SIMD (single‐instruction multiple‐data) architectures and ultra‐low power operation combined with real‐time compute and I/O reconfigurability opens unprecedented opportunities for executing sophisticated signal processing algorithms faster and within a much lower energy budget. Here, we present an unconventional Fast Fourier Transform (FFT) implementation scheme for the IBM Cell, named transverse vectorization. It is shown to outperform (both in terms of timing and GFLOP throughput) the fastest FFT results reported to date for the Cell in the open literature. We also provide the first results for multi‐FFT implementation and application on the novel, ultra‐low power Coherent Logix HyperX processor. Copyright