Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Pattern Recognition and Machine Learning

We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

Unmanned aerial vehicles (UAVs) have enormous potential in the public and civil domains. These are particularly useful in applications, where human lives would otherwise be endangered. Multi-UAV systems can collaboratively complete missions more efficiently and economically as compared to single UAV systems. However, there are many issues to be resolved before effective use of UAVs can be made to provide stable and reliable context-specific networks. Much of the work carried out in the areas of mobile ad hoc networks (MANETs), and vehicular ad hoc networks (VANETs) does not address the unique characteristics of the UAV networks. UAV networks may vary from slow dynamic to dynamic and have intermittent links and fluid topology. While it is believed that ad hoc mesh network would be most suitable for UAV networks yet the architecture of multi-UAV networks has been an understudied area. Software defined networking (SDN) could facilitate flexible deployment and management of new services and help reduce cost, increase security and availability in networks. Routing demands of UAV networks go beyond the needs of MANETS and VANETS. Protocols are required that would adapt to high mobility, dynamic topology, intermittent links, power constraints, and changing link quality. UAVs may fail and the network may get partitioned making delay and disruption tolerance an important design consideration. Limited life of the node and dynamicity of the network lead to the requirement of seamless handovers, where researchers are looking at the work done in the areas of MANETs and VANETs, but the jury is still out. As energy supply on UAVs is limited, protocols in various layers should contribute toward greening of the network. This paper surveys the work done toward all of these outstanding issues, relating to this new class of networks, so as to spur further research in these areas.

Survey of Important Issues in UAV Communication Networks

Power Aware Routing in Mobile Ad Hoc Networks

Cognitive radio (CR) technology is envisaged to solve the problems in wireless networks resulting from the limited available spectrum and the inefficiency in the spectrum usage by exploiting the existing wireless spectrum opportunistically. CR networks, equipped with the intrinsic capabilities of the cognitive radio, will provide an ultimate spectrum-aware communication paradigm in wireless communications. CR networks, however, impose unique challenges due to the high fluctuation in the available spectrum as well as diverse quality-of-service (QoS) requirements. Specifically, in cognitive radio ad hoc networks (CRAHNs), the distributed multi-hop architecture, the dynamic network topology, and the time and location varying spectrum availability are some of the key distinguishing factors. In this paper, intrinsic properties and current research challenges of the CRAHNs are presented. First, novel spectrum management functionalities such as spectrum sensing, spectrum sharing, and spectrum decision, and spectrum mobility are introduced from the viewpoint of a network requiring distributed coordination. A particular emphasis is given to distributed coordination between CR users through the establishment of a common control channel. Moreover, the influence of these functions on the performance of the upper layer protocols, such as the network layer, and transport layer protocols are investigated and open research issues in these areas are also outlined. Finally, a new direction called the commons model is explained, where CRAHN users may independently regulate their own operation based on pre-decided spectrum etiquette.

/pdf/crahns-cognitive-radio-ad-hoc-networks-1odtmohw8e.pdf

CRAHNs: Cognitive radio ad hoc networks

Practical design and performance solutions for every ad hoc wireless networkAd Hoc Wireless Networks comprise mobile devices that use wireless transmission for communication. They can be set up anywhere and any time because they eliminate the complexities of infrastructure setup and central administration-and they have enormous commercial and military potential. Now, there's a book that addresses every major issue related to their design and performance. Ad Hoc Wireless Networks: Architectures and Protocols presents state-of-the-art techniques and solutions, and supports them with easy-to-understand examples. The book starts off with the fundamentals of wireless networking (wireless PANs, LANs, MANs, WANs, and wireless Internet) and goes on to address such current topics as Wi-Fi networks, optical wireless networks, and hybrid wireless architectures. Coverage includes: Medium access control, routing, multicasting, and transport protocols QoS provisioning, energy management, security, multihop pricing, and much more In-depth discussion of wireless sensor networks and ultra wideband technology More than 200 examples and end-of-chapter problemsAd Hoc Wireless Networks is an invaluable resource for every network engineer, technical manager, and researcher designing or building ad hoc wireless networks.

Ad Hoc Wireless Networks: Architectures and Protocols

primary challenge in responding to both natural and man-made disasters is communication. This has been highlighted by recent disasters such as the 9/11 terrorist attacks and Hurricane Katrina [2, 5, 6]. A problem frequently cited by responders is the lack of radio interoperability. Responding organizations must work in concert to form a cohesive plan of response. However, each group—fire, police, SWAT, HazMat—com-municates with radios set to orthogonal frequencies , making inter-agency communications extremely difficult. The problem is compounded as more local, state, and federal agencies become involved. The communication challenges in emergency response go far beyond simple interop-erability issues. Based on our research, practical observation of first responder exercises and drills, and workshop discussions, we have identified three categories of communication challenges: technological, sociological, and organizational. These three major areas are key to developing and maintaining healthy and effective disaster communication systems. The primary technological challenge after a disaster is rapid deployment of communication systems for first responders and disaster management workers. This is true regardless of whether the communications network has been completely destroyed (power, telephone, and/or network connectivity infrastructure), or, as in the case of some remote geographic areas, the infrastructure was previously nonex-istent. Deployment of a new system is more complicated in areas where partial communication infrastructures remain, than where no prior communication networks existed. This can be due to several factors including interference from existing partial communication networks and the dependency of people on their prior systems. Another important obstacle to overcome is the multi-organizational radio interoperability issue. To make future communication systems capable of withstanding large-or medium-scale disasters, two technological solutions can be incorporated into the design: dual-use technology and built-in architectural and protocol redundancy. Dual-use technology would enable both normal and emergency operational modes. During crises, such devices would work in a network-controlled fashion, achieved using software agents within the communication

Communication challenges in emergency response

An ad hoc wireless network (AWN) is a collection of mobile hosts forming a temporary network on the fly, without using any fixed infrastructure. Characteristics of AWNs such as lack of central coordination, mobility of hosts, dynamically varying network topology, and limited availability of resources make QoS provisioning very challenging in such networks. In this paper, we describe the issues and challenges in providing QoS for AWNs and review some of the QoS solutions proposed. We first provide a layer-wise classification of the existing QoS solutions, and then discuss each of these solutions.

/pdf/quality-of-service-provisioning-in-ad-hoc-wireless-networks-2n3sxhm5la.pdf

Quality of service provisioning in ad hoc wireless networks: a survey of issues and solutions

Ad hoc wireless networks are self-organizing dynamic topology networks formed by a collection of mobile nodes through radio links. Minimal configuration absence of infrastructure and quick deployment make them convenient for emergency situations other than military applications. Multicasting plays a very crucial role in the application of Ad hoc networks. As the number of participants increases scalability of the multicast protocol becomes an important issue. Among the existing multicast protocols On Demand Multicast Routing Protocol (ODMRP) perfo exhibits a high packet delivery ratio even at high mobility. But ODMRP suffers from higher control overhead as the network size and the number of sources increase.In this paper we propose an efficient multicast routing protocol for Ad hoc wireless networks. This protocol reduces the control overhead by dynamically classifying the sources into Active and Passive categories. The control overhead is significantly reduced by about 30% compared to ODMRP which contributes to the scalability of the protocol. We study the effectiveness of the proposed multicast routing protocol by simulation studies and the results show that the multicast efficiency is increased by 10--15% and packet delivery ratio is also improved at high network load.

/pdf/a-dynamic-core-based-multicast-routing-protocol-for-ad-hoc-4udjck0vwf.pdf

A dynamic core based multicast routing protocol for ad hoc wireless networks

Multi-hop cellular network (MCN) is an architecture proposed by Lin and Hsu (see INFOCOM 2000. IEEE, 2000) for wireless communication & MCNs combine the benefits of having a fixed infrastructure of base stations and the flexibility of ad-hoc networks. They are capable of achieving much higher throughput than current cellular systems, which can be classified as single-hop cellular networks (SCNs). This work concentrates on MCNs and SCNs using the IEEE 802.11 standard for wireless LANs. We provide a general overview of the architecture and the issues involved in the design of MCNs, in particular the challenges to be met in the design of a routing protocol. We extend the work of Lin and Hsu to enhance the throughput of such networks further. We propose a routing protocol for use in such networks. We conduct extensive experimental studies on the performance of MCNs and SCNs under various load conditions (both TCP and UDP). Then studies clearly indicate that MCNs with the proposed routing protocol are a viable alternative for SCNs, in fact they provide much higher throughput.

B. S. Manoj

Papers

Ad Hoc Wireless Networks: Architectures and Protocols

Communication challenges in emergency response

Quality of service provisioning in ad hoc wireless networks: a survey of issues and solutions

A dynamic core based multicast routing protocol for ad hoc wireless networks

Multi-hop cellular networks: the architecture and routing protocols