Mohan Kumar

Rochester Institute of Technology | RIT · Department of Computer Science

Pervasive networks formed by users' mobile devices have the potential to exploit a rich set of distributed service components that can be composed to provide each user with a multitude of application level services. However, in many challenging scenarios, opportunistic networking techniques are required to enable communication as devices suffer fro...

The degree of adaptiveness has a major impact on the performance of an adaptive routing method. An improved turn model-based routing method that provides a high degree of adaptiveness for a 2D mesh is presented. The proposed method reduces restrictions on the routing turns significantly and hence can provide path diversity using additional routes (...

Pervasive networks formed by users’ mobile devices have the potential to exploit a rich set of distributed service components that can be composed to provide each user with a multitude of application level services. However, in many challenging scenarios, opportunistic networking techniques are required to enable communication as devices suffer fro...

Network-on-Chip (NoC) is emerging as a promising communication paradigm to overcome bottleneck of traditional bus-based interconnects for future micro-architectures (MPSoC and CMP). One of current issue in NoC routing is the use of acyclic channel dependency graph (ACDG) for deadlock freedom prohibiting certain routing turns. Thus, ACDG reduces the...

Network on chip (NoC) is emerging as a promising solution to overcome bus bottleneck for future multi core chips. Fault tolerance and quality of service issues are potential challenges for NoCs. In this paper, we propose a cost-effective fault tolerant routing algorithm for irregular 2D mesh without use of routing tables. We use one hop visibility...

In wireless sensor networks (WSNs), resource-constrained nodes are expected to operate in highly dynamic and often unattended environments. Hence, support for intelligent, autonomous, adaptive and distributed resource management is an essential ingredient of a middleware solution for developing scalable and dynamic WSN applications. In this article...

The rapidly emerging area of pervasive computing faces many challenging research issues critical to application developers. Wide heterogeneity of hardware, software, and network resources pose veritable coordination problems and demand thorough knowledge of individual elements and technologies. In order to ease this problem and to aid application d...

An opportunistic contact between two mobile devices takes place when they are within communication range of each other. Typically, cyber-physical environments comprise a number of mobile devices that are likely to make opportunistic contacts in time and space. In the recent past, researchers have exploited opportunistic links mostly for routing and...

In opportunistic environments, tasks such as content sharing and service execution among remote devices are facilitated by relays (devices with short-range wireless connectivity) that receive data, move around, and then forward the data. To achieve high throughput, it is important to secure forwarding and provide incentives for participation by rel...

Opportunistic networks are essentially distributed networks with transient connectivity among nodes. Nodes in opportunistic networks are resource constrained, mobile and infrequently come in contact with each other. In such a distributed network, nodes may require exclusive access to a shared object or resource. Ensuring freedom from starvation is...

The physical environment is becoming more and more saturated with computing and communication entities that interact among themselves, as well as with users: virtually everything will be enabled to source information and respond to appropriate stimuli. In this technology-rich scenario, real-world components interact with cyberspace via sensing, com...

Data acquired from multiple sensors can be fused at a variety of levels: the raw data level, the feature level, or the decision level. An additional dimension to the fusion process is temporal fusion, which is fusion of data or information acquired from multiple sensors of different types over a period of time. We propose a technique that can perfo...

Wireless sensor networks (WSNs) have become an enabling technology for a wide range of applications. In contrast with traditional scenarios where static sensor nodes are densely deployed, a sparse WSN architecture can also be used in many cases. In a sparse WSN, special mobile data collectors (MDCs) are used to gather data from ordinary sensor node...

This paper proposes a middleware architecture to enable seamless content sharing in highly dynamic networks, such as those involving a number of aerial unmanned autonomous vehicles (UAVs), which are characterized by constantly changing connectivity and network topology. The proposed middleware maintains up-to-date network status as well as metadata...

Pervasive networks formed by users' mobile devices have the potential to exploit a rich set of distributed service components that can be composed to provide each user with a multitude of application level services. However, mobile and pervasive networks suffer from intermittent connectivity, disconnections and partitions, such that opportunistic n...

A series of opportunistic contacts in space and time among devices carried by mobile users, can be utilized to forward messages from one user to another in the absence of an end-to end connected path. Existing routing metrics exhibit efficient performance in either homogeneous (users have similar mobility characteristics) or specific heterogeneous...

Opportunistic networks are created dynamically by exploiting contacts between pairs of mobile devices that come within communication range. While forwarding in opportunistic networking has been explored, investigations into asynchronous service provisioning on top of opportunistic networks are unique contributions of this paper. Mobile devices are...

Most of the routing and replication algorithms for Mobile Peer to Peer (M-P2P) networks assume the network to be large and therefore, the architecture and algorithms are designed to be scalable. These algorithms however may not perform well with limited number of nodes in a network such as of UAVs. Thus, it is better to design algorithms to increas...

Support for autonomous and adaptive management is essential for many wireless sensor network (WSN) applications expected to be functioning over long periods of time. WSN management is further complicated by heterogeneity in terms of resources as well as applications deployed on those resources. In this paper, we present, Distributed Reinforcement L...

Varied context reasoning approaches are used across a variety of applications in the pervasive computing domain including: health monitoring, intrusion detection, airport security and military target tracking. The same types of context are being inferred in diverse ways across a number of platforms. For example, human activity has been inferred usi...

Service composition schemes create high-level application services by combining several basic services. Service composition schemes for dynamic, open systems, such as those found in pervasive environments, must be cognizant of the possibility of failures and attacks. In open systems, it is seldom feasible to guarantee the reliability of each node p...

Devices in pervasive systems are resource constrained, heterogeneous, mobile and personal. The devices may seek or provide such services as data compression, encryption, image analysis, query processing and other types within a local, but dynamic network. In order to enable sharing of services and resources, it is necessary that the middleware faci...

Social networking has recently flourished in popularity through the use of social websites. Pervasive computing resources have allowed people stay well-connected to each other through access to social networking resources. We take the position that utilizing information produced by relationships within social networks can assist in the establishmen...

Sparse wireless sensor networks (WSNs) are being effectively used in several applications, which include transportation, urban safety, environment monitoring, and many others. Sensor nodes typically transfer acquired data to other nodes and base stations. Such data transfer operations are critical, especially in sparse WSNs with mobile elements. In...

When two devices come into contact, albeit opportunistically, it provides a great opportunity to match services to resources, exchange information, cyberforage, execute tasks remotely, and forward messages.

Most of the routing and replication algorithms assume the network to be large and therefore, the architecture and algorithms are designed to be scalable. These algorithms however may not perform well with limited number of nodes in a network of UAVs. It is better to design and simulate such algorithms to increase the efficiency in a small network a...

Opportunistic computing has emerged as a new paradigm in computing, leveraging the advances in pervasive computing and opportunistic networking. Nodes in an opportunistic network avail of each others' connectivity and mobility to overcome network partitions. In opportunistic computing, this concept is generalised, as nodes avail of any resource ava...

Peer-to-peer (P2P) architectures are gaining popularity and importance for applications ranging from massive-scale Internet content delivery to mobile social networks. Such P2P systems must provide directory services for locating peers with the desired content and services. These directory services are themselves decentralized, such as with distrib...

The sensing context plays an important role in many pervasive and mobile computing applications. Continuing from previous work [D. Phung, B. Adams, S. Venkatesh, Computable social patterns from sparse sensor data, in: Proceedings of First International Workshop on Location Web, World Wide Web Conference (WWW), New York, NY, USA, 2008, ACM 69–72.],...

Effective security mechanisms are essential to the widespread deployment of pervasive systems. Much of the research focus on security in pervasive computing has revolved around distributed trust management. While such mechanisms are effective in specific environments, there is no generic framework for deploying and extending these mechanisms over a...

This paper examines the recovery of user context in indoor environmnents with existing wireless infrastructures to enable assistive systems. We present a novel approach to the extraction of user context, casting the problem of context recovery as an unsupervised, clustering problem. A well known density-based clustering technique, DBSCAN, is adapte...

Peer-to-peer (P2P) has become a mainstream architecture in numerous diverse distributed applications. However current P2P systems do not provide consistency guarantees under multiple reader multiple writer scenarios. Such a feature is desirable as well as necessary for supporting more diverse applications than merely file-sharing systems. In this p...

Pervasive computing environments are characterized with an array of heterogeneous devices. Within such environments, it is necessary to accommodate devices with restrictions on available resources through cooperation of devices that have greater resource availability. Traditionally, such cooperation is achieved based on information available prior...

An efficient addressing and service location scheme is essential for auto-configuration, seamless communication and collaboration among ad hoc network nodes in pervasive computing environments. In this paper, we propose an efficient and simple scheme called CoReS (Configuration and Registration Scheme), for address auto-configuration and service re...

Trust management is essential for secure node collaboration in ubiquitous computing environments for mission critical applications in military, crisis management, telemedicine and others. In this paper, we design and develop a novel hierarchical architecture called NeVo (Network of Volunteers) to facilitate trust management. The architecture uses a...

Parallel Pervasive Systems (P 2S) comprise an ad hoc network of pervasive devices such as cell phones, handheld computers, laptops, sensors and other devices that essentially form a parallel system. Most of the current work in pervasive computing and mobile adhoc networks exploit resources on remote devices to execute compute intensive tasks. In th...

In open environments, such as mobile peer-to-peer systems, participants may need to access resources from unknown users. A critical security concern in such systems is the access of faulty resources, thereby wasting the requester's time and energy and possibly causing damage to her system. A common approach to mitigating the problem involves reputa...

Mobile clients need to access information anytime, anywhere from various legacy and existing applications on the wired network with minimum effort and cost. The challenge is to support pervasive information access to disparate data sources such as World Wide Web (WWW) and databases that can provide useful information to mobile clients without burde...

Sensor fusion is concerned with gaining information from multiple sensors by fusing across raw data, features or decisions. Traditionally these fusion processes only concern fusion at specific points in time. However recently, there is a growing interest in inferring the behavioural aspects of environments or objects that are monitored by multisens...

Applications and services are increasingly dependent on networks of smart sensors embedded in the environment to constantly sense and react to events. In a typical sensor network application, information is collected from a large number of distributed and heterogeneous sensor nodes. Information fusion in such applications is a challenging research...

Research on security in peer-to-peer (P2P) systems is dominated by reputation-based solutions. These solutions propagate opinions about other peers in order to help identify the best set of peers to utilize. In this paper, we model peers with utility functions and use those functions to examine the case in which an individual peer participates in a...

In open environments, such as mobile peer-to-peer sys-tems, participants may need to access resources from users they don't know. One of the most critical security issues this raises is that the resources accessed could be faulty, thereby wasting the requester's time and energy and possibly caus-ing damage to her system. A common approach to mitiga...

With the increase in the number of mobile devices and their network capabilities, users expect transparent access to available services in their pervasive environment. However, heterogeneity and interoperability issues persist in existing mechanisms. In this paper, we present a lightweight framework, PerSON (Service Overlay Network for Pervasive En...

Service-oriented architectures (SOAs) promise to provide transparency to resource access by exposing the resources available as services. SOAs have been employed within pervasive computing systems to provide essential support to user tasks by creating services representing the available resources. The mechanism of combining two or more basic servic...

Peer-to-peer (P2P) systems are currently used in a variety of applications. File sharing applications and ad hoc networking have fueled the usage of these systems. P2P systems generate new challenges in scalability, fairness, and quality of service. Current systems often approach these challenges through incentive-based solutions and structured sys...

The paper proposes a novel improvised architecture for providing fundamental services through exploitation of node heterogeneity so that relatively stable and capable devices cooperate and assist resource-poor devices. The novel hierarchical architecture called NeVo (Network of Volunteers) uses a small subset of the volunteer nodes to perform basic...

Abstract As more and more applications with dynamic flles are introduced in peer-to-peer (P2P) systems, flle consistency maintenance becomes important. In this paper, we propose a novel flle consistency maintenance algorithm, called Update Propagation Through Replica Chain (UPTReC), for decentralized and unstructured peer-to-peer (P2P) systems. UPT...

In recent years, ubiquitous computing applications span such areas as telemedicine, banking, and transportation that require user privacy protection. The realization of context-aware ubiquitous computing exasperates existing privacy concerns. Ubiquitous computing applications demand new privacy enhancing technologies for the information and communi...

We propose a service discovery architecture called VSD (Service Discovery based on Volunteers) for pervasive computing environments. The proposed architecture exploits stable and resourceful nodes, called volunteers, that perform directory services in the network. The VSD architecture recognizes node heterogeneity in terms of mobility and capabilit...

With more and more online game players having access to broadband Internet connections and high performance computers, peer-to-peer architecture offers an attractive solution for online multiplayer game design. However, message synchronization and cheat proof are two major challenges in implementing a fully distributed peer-to-peer game system. In...

Pervasive computing paradigm is characterized by the presence of a diverse variety of computing and communicating devices. The vision of pervasive computing is to enable effective support for user tasks by utilizing the devices carried by the users and those available within the infrastructure around the users. Emergency response is very critical t...

Increasing popularity of the pervasive computing paradigm on one hand and the technological developments on the other, have paved the way for development and deployment of pervasive services in the everyday habitat. The service providers, who build, operate and manage services would want to maximize their revenues, and at the same time, the users w...

Pervasive Computing applications require continual and autonomous availability of ‘what I want’ of information acquisition and dissemination in a proactive yet unobtrusive way. Mobility and heterogeneity of pervasive environments make this problem even more challenging. Effective use of middleware techniques, such as caching, can overcome the dynam...

Caching frequently accessed data objects at the local buffer of a mobile user (MU) has been found to be very effective in improving information availability in mobile wireless environments. Several mechanisms have been proposed in the literature to address the challenging problem of cache consistency in cellular wireless networks. However, these me...

In this paper we present our system for online context recognition of multimodal sequences acquired from multiple sensors. The system uses Dynamic Time Warping (DTW) to recognize multimodal sequences of different lengths, embedded in continuous data streams. We evaluate the performance of our system on two real world datasets: 1) accelerometer data...

As the tremendous growth in peer-to-peer (P2P) applications, the issues related to file consistency become critical. In this paper, an algorithm for file Consistency Maintenance through Virtual servers (CMV) is proposed for unstructured and decentralized P2P systems. In CMV, consistency of each dynamic file is maintained by a virtual server (VS). A...

In this chapter, we have presented an overview of the enabling technologies for the emergence of pervasive computing and communication infrastructures. While the Internet will perhaps continue to be the backbone of pervasive computing, the tremendous advances in wireless mobile communications allow the creation of ubiquitous networks with very litt...

Availability of services to users and applications is a critical issue in mobile and pervasive computing environments replete with hundreds and thousands of smart devices. In such environments, devices such as sensors, embedded processors, personal servers, cell phones and PDAs have limited resources in terms of CPU, memory, communication bandwidth...

We propose an efficient scheme called CoReS (Configuration and Registration Scheme) that integrates address assignment and service location for ad hoc networks prevalent in pervasive computing environments. CoReS exploits node heterogeneity such that more capable and stable nodes serve oth- ers. CoReS allocates addresses to individual nodes locally...

We propose a service discovery architecture called VSD (service discovery based on volunteers) for heterogeneous and dynamic pervasive computing environments. The proposed architecture uses a small subset of the nodes called volunteers that perform directory services. Relatively stable and capable nodes serve as volunteers, thus recognizing node he...

In mobile computing environments, vital resources like battery power and wireless channel bandwidth impose significant challenges in ubiquitous information access. In this paper, we propose a novel energy and bandwidth efficient data caching mechanism, called GreedyDual Least Utility (GD-LU), that enhances dynamic data availability while maintainin...

The Grid is an integrated infrastructure that can play the dual roles of a coordinated resource consumer as well as a donator in distributed computing environments. In a mobile grid environment, the Grid acts as a resource hungry consumer whereas in ubiquitous computing environments, it has the inherent potential to provide services to applications...

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Several applications and services employ networks of embedded sensors to monitor events in the environment. To be effective, such applications should cope with sensor network limitations and characteristics, such as resource constraints, dynamicity and heterogeneity. In sensor network applications, there is a need for some level of fusion of inform...

Mobile Peer-to-Peer (MP2P) systems consist of mobile peers that collaborate with each other to complete application problems. Information sharing in such environments is a challenging problem due to the fundamental limitations of battery power, wireless bandwidth, and users' frequent mobility. We proposed a novel scheme, called Proximity Regions fo...

Mobile peer-to-peer (MP2P) networks consist of mobile devices that communicate with each other via short-range wireless transmissions to facilitate sharing of information among them. Such networks present a constrained communication environment due to fundamental limitations of battery power and wireless bandwidth, and users' frequent mobility. The...

Digital multimedia has gained popularity due to the huge success of the Internet. Users acquire and disseminate multimedia information using different types of devices and communication channels. On the other hand, personal devices, such as laptops, PDAs and smart phones, are not only capable of producing and rendering multimedia, but also support...

An efficient addressing scheme is necessary for auto-configuration and seamless communication in pervasive computing environments. In this paper, we propose an efficient and simple scheme called CoReS (Configuration and Registration Scheme), for address auto-configuration integrated with service registration/location in dynamic mobile ad hoc networ...

It is a challenging task to develop applications and systems that cater to the needs of ever increasing multimedia applications. Additionally, in pervasive computing environments, multimedia data needs to be delivered to heterogeneous devices with varying capabilities over a variety of communication channels. The objective of this research is to dy...

Due to deterministic and fast lookup performance, ternary content addressable memory (TCAM) has recently been gaining popularity in general policy filtering (PF) for packet classification in high-speed networks. However, the PF table update poses significant challenges for efficient use of TCAM. To avoid erroneous and inconsistent rule matching, th...

Service discovery is an important component of wireless and mobile network systems. An efficient service discovery mechanism would ensure high availability of services to users and applications, and high utilization of services. In this chapter, we discuss various issues and challenges facing the design and selection of a proper service discovery m...

In the literature, there exit two types of cache consistency maintenance algorithms for mobile computing environments: stateless and stateful. In a stateless approach, the server is unaware of the cache contents at a mobile user (MU). Even though stateless approaches employ simple database management schemes, they lack scalability and ability to su...

Abstract Mobile wireless sensor networks (MWSNs) will enable information systems to gather detailed information about the environment on an unprecedented scale. These self-organising, distributed networks of sensors, processors and actuators that are capable of movement have a broad range of potential applications, including military reconnaissance...

We propose a novel algorithm, called update propagation through replica chain (UPTReC), to maintain file consistency in decentralized and unstructured peer-to-peer (P2P) systems. In UPTReC, each file has a logical replica chain composed of all replica peers (RPs) which are defined as peers that have replicas of the file. Each RP acquires partial kn...

Caching techniques have been successfully employed to overcome some of the problems posed by disconnection and/or limited bandwidth in mobile environments. Demand driven and prefetching techniques to maintain optimal caches have been found to have limited success in such environments. We develop profile based methods to maintain and enhance data av...

In this paper, we propose a novel algorithm, called update propagation through replica chain (UPTReC), to maintain file consistency in decentralized and unstructured peer-to-peer (P2P) systems. In UPTReC, each file has a logical replica chain composed of all replica peers (RPs) which are defined as peers that have replicas of the file. Each RP acqu...

In the literature, there exit two types of cache consistency maintenance algorithms for mobile computing environments: stateless and stateful. In a stateless approach, the server is unaware of the cache contents at a mobile user (MU). Even though stateless approaches employ simple database management schemes, they lack scalability and ability to su...

Summary form only given. In mobile distributed systems, vital resources like battery power and wireless channel bandwidth impose significant challenges in ubiquitous information access. We propose a novel energy and bandwidth efficient data caching mechanism, called greedydual least utility (GD-LU), that enhances dynamic data availability while mai...

In this paper, we propose a novel caching scheme, called energy efficient cooperative caching with optimal radius (ECOR), to overcome the limitations of hybrid wireless networks such as high energy consumption, long access latency and poor load balance. In ECOR, each mobile user (MU) forms a cooperation zone with MUs in proximity to share cached da...

The fully connected network possesses extremely good topological, fault-tolerant, and embedding properties. However, due to its high degree, the fully connected network has not been an attractive candidate for building parallel computers. On the other hand, tree-based networks are popular as parallel computer networks, even though they suffer from...

Today, pervasive computing technologies are being developed to provide automated, real-time, continual, and unobtrusive user services in dynamic heterogeneous environments such as telemedicine, manufacturing, space endeavors, crisis management, and military. However, the full potential of pervasive computing cannot be realized without enabling midd...

Using Ternary Content Addressable Memory (TCAM) for general policy filtering has been gaining pop-ularity due to TCAM's deterministic and fast lookup per-formance. However, the policy table updating poses signifi-cant challenge for efficient use of TCAM for policy filtering. To avoid erroneous and inconsistent rule matching while a policy table is...

Using Ternary Content Addressable Memory (TCAM) for general policy filtering has been gaining popularity due to TCAM's deterministic and fast lookup performance. However, the policy table updating poses significant challenge for efficient use of TCAM for policy filtering. To avoid erroneous and inconsistent rule matching while a policy table is bei...

The features and applications of pervasive information community organization (PICO) - a framework for creating mission-oriented dynamic communities of autonomous software entities that perform tasks for user and devices, are discussed. It is stated that service-provisioning communities allow a high degree of transparency between users and applicat...

In this paper we introduce a novel framework for pervasive computing called PICO (Pervasive Information Community Organization). PICO allows distributed computing and communication capabilities at higher and lower levels of abstraction, resulting in a significant improvement in current models of information systems for dynamic applications such as...

We study the extent to which crashes in emerging market currencies are predictable using simple logit models based on lagged macroeconomic and financial data. To evaluate our model, we calculate trading strategies in which an investor goes long or short in the currency depending on whether crash probabilities are low or high. When we estimate the m...

In this paper, three types of cache consistency maintenance strategies involving invalidation reports (IRs) are proposed for application in mobile environments. The three strategies: homogeneous IR, inhomogeneous IR without roaming check, and inhomogeneous IR with roaming check are applied to Timestamp (TS) and Scalable Asynchronous Cache Consisten...

In this paper, we propose a novel cache consistency maintenance scheme, called Scalable Asynchronous Cache Consistency Scheme (SACCS), for mobile environments. It relies on the following three key features: (1) Use of flag bits at server and MU's cache to maintain cache consistency; (2) Use of an identifier (ID) for each entry in MUs cache after it...

TCP performance degrades with increasing round trip time (rtt) due to longer slow start periods and slower rate of increase of the congestion window. The proposed, PTS (proxy transport service) is an active network based service, that can improve the end-to-end perfor- mance of TCP connections with large rtt's. PTS also reduces the response time of...

Mobile users connected to wireless networks expect performance comparable to those on wired networks for interactive multimedia applications. Satisfying Quality of Service (QoS) requirements for such applications in wireless networks is a challenging problem due to limitations of low bandwidth, high error rate and frequent disconnections of wireles...

We propose to apply novel pervasive computing technologies to rev-olutionize manufacturing of extremely complex products such as com-mercial and defense aerospace systems. Such manufacturing systems consist of a collection of extensive manual and automated data, par-ticipation of many specialized personnel and use of distributed product data reposi...

In this paper, we investigate the potential of caching to improve QoS in the context of continuous media applications over wired best-effort networks. We propose the use of a flexible caching scheme, called GD-Multi in caching continuous media (CM) objects. An important novel feature of our scheme is the provision of user or system administrator in...

Speculative prefetching has been proposed to improve the response time of network access. Previous studies in speculative prefetching focus on building and evaluating access models for the purpose of access prediction. This paper investigates a complementary area which has been largely ignored, that of performance modeling. We analyze the performan...

In mobile environments, efficient binding update delivery results in fast adaptation to the effects of migration. The scheme discussed performs the update using IP multicast. The proposed active delivery scheme⁺ (ADS⁺) is an extension of the ADS earlier proposed by the authors. Unlike ADS, ADS⁺ does not assume the u...

This paper presents a cooperative caching architecture suitable for continuous media (CM) proxy caching in MANET environments. The proposed scheme introduces an application manager component, which is interposed between traditional Internet CM applications and the network layer. The application manager transparently performs data location and servi...