Adaptive Call Admission Control in Wireless Multimedia Network

Authors: Marjan Bozinovski and Liljana Gavrilovska

Abstract: There is a tremendous growth of broadband multimedia services  in mobile cellular networks. Call admission control (CAC) is the most  significant issue in quality of service (QoS) provisioning for these services.  We propose an adaptive CAC, which upgrades the upper limit  (UL) scheme and is verified through the simulation.  The proposed algorithm allows each cell to accept a new call if the  estimated average differential of each multiclass handoff  failure probability is non-positive.  The generic form of the algorithm is independent of cellular network structure.

An Architecture For The Effective Support Of Adaptive Context-Aware Applications

Authors: Christos Efstratiou, Keith Cheverst, Nigel Davies and Adrian Friday

Abstract:  Mobile applications are required to operate in environments characterised  by change. More specifically, the availability of resources and  services may change significantly during a typical period of system  operation. As a consequence, adaptive mobile applications need to be  capable of adapting to these changes to ensure they offer the best  possible level of service to the user. Our experiences of developing and  evaluating adaptive context-aware applications in mobile environments has  led us to believe that existing architectures fail to provide the necessary  support for such applications. Moreover, we believe that current research  in this area is also failing to address the core requirements of this  class of application, i.e. the need to support coordinated action between  application and system components and the resolution of conflicts caused  by the need to adapt to multiple contextual triggers. In this paper, we  discuss the shortcomings of existing approaches and present work on our own  architecture that has been designed to meet the key requirements of  context-aware adaptive applications.

Bandwidth-Conserving Cache Validation Schemes in a Mobile Database System

Authors: Hyunchul Kang and Sangmin Lim

Abstract: Due to advance of wireless communication technology, data service in mobile  computing environment has become a reality, and efficient mobile data management  is more demanded. Caching at a mobile host could conserve the limited wireless  bandwidth while reducing the query response time, and yet cache consistency  needs to be maintained. The basic cache consistency scheme is for the server to  periodically broadcast an invalidation report that identifies the  updated data objects so that the mobile hosts may purge  the stale data objects from their caches.  In case that long period of disconnection prevents a reconnecting mobile host  from guaranteeing validity of its cache based solely on the invalidation report  received, the mobile host could request the server to check validity of its cache.  In this paper, we propose a set of new cache validation schemes called  2PCV (2 Phase Cache Validation), 1PCV (1 Phase Cache Validation), and  BCV (Broadcast Cache Validation) that can efficiently conserve the bandwidth both  in cache validation and query processing afterwards. Our schemes (1) avoid false  invalidation, (2) are not forced to discard the entire cache at any case, (3) do not  require the server to maintain the update history other than that necessary for the  periodic broadcasting of the invalidation report, and (4) effectively deal with  the situation when the contention on the wireless channels for cache validation is severe.  The performance of our schemes is evaluated through the detailed simulation experiments.

A Mobility Framework for Ad Hoc Wireless Networks

Authors: Xiaoyan Hong, Taekjin Kwon, Mario Gerla, Daniel Lihui Gu and Guangyu Pei

Abstract:   Mobility management in ad hoc wireless networks faces many challenges.  Mobility constantly causes the network topology to change. In order to  keep accurate routes, the routing protocols must dynamically readjust to  such changes. Thus, routing update traffic overhead is tremendously  increased. Different mobility patterns have in general different impact  on a specific network protocol or application. Consequently the network  performance will be strongly influenced by the nature of the mobility  pattern. In the past, mobility models were rather casually used to  evaluate network performance under different routing protocols. Here, we  propose a universal mobility framework, Mobility Vector Model, which can  be used for recreating the various mobility patterns produced by  different applications. Case studies on optimal transmission range as a  function of mobility and on network performance under various mobility  models are presented in the paper. Simulation results show that  excessively large transmission range will not improve network performance  significantly. There is an optimal range between 1-2 times the mean node  distance for free space channel. Also, simulation results show that  different mobility models produce different performance for a variety of  routing protocols (AODV,DSR,FSR). When choosing routing protocols for  ad hoc network applications, performance studies using multiple mobility  models are recommended. The Mobility Vector model can provide a realistic  and flexible framework for reproducing various models.

Personal Workflow Management in Support of Pervasive Computing

Authors: San-Yih Hwang, Jeng-Kuen Chiu, and Wan-Shiou Yang

Abstract:  As mobile devices are getting powerful, reliable, and inexpensive,  more and more personal services have been introduced to individuals  via their mobile devices. These services enable users to perform a  broad range of activities at any time and anywhere. While a lot of  research and development effort has been focusing on extending the  cope of activities that can be carried out in mobile devices,  no attempt has been made to provide process-oriented services.  In this paper, we propose a personal workflow management system that  enables the specification and execution of personal processes. This  system helps manage and execute these processes, serving the role of  planning, coordinating, and reminding task executions so as to  accomplish predefined personal goals. Activities of a process are  related through their data dependencies, which are specified via a  formal model called metagraph. The analytical capability of  metagraphs makes it easy to answer many process related inquiries.  We propose an SQL-like language and a set of operations for the  specification of possible inquiries. Research issues on the  implementation of a personal workflow management system are also  discussed.

An Agent-Based Architecture using XML for Mobile Federated Database Systems

Authors: Carlos Sanchez,  Lee Gruenwald

Abstract: We advocate the use of agents to model a system that allows us to integrate  and protect information stored in both mobile and fixed devices, while trying  to preserve a consistent authorization state. We propose a system called HAFS,  which makes use of an object oriented data model to enforce security across  the mobile federation and XML as a language to represent and exchange the  common meta-data among agents.

Operating System and Algorithmic Techniques for Energy  Scalable Wireless Sensor Networks

Authors: Amit Sinha,  Anantha P. Chandrakasan

Abstract:  An system-level power management technique for massively  distributed wireless microsensor networks is proposed. A  power aware sensor node model is introduced which enables  the embedded operating system to make transitions to different  sleep states based on observed event statistics. The adaptive  shutdown policy is based on a stochastic analysis and renders  desired energy-quality scalability at the cost of latency and  missed events. The notion of algorithmic transformations that  improve the energy quality scalability of the data gathering  network are also analyzed.

Towards a Programmable Mobile IP

Authors: Alvin T.S. Chan,  Dan He, Siu Nam Chuang

Abstract:  This paper describes the design and implementation of a highly configurable and robust Mobile IP framework that employs active networking principles. Through the provision of open programmable interfaces and execution environment, new mobile services or application-specific customized services can be rapidly developed and deployed within the Mobile IP networking environment. ANTS [11] is being employed as the baseline active network execution environment for the implementation of our programmable Mobile IP framework. In particular, we have extended ANTS considerably to export mobile IP native interfaces to support mobile specific functionalities. The design of our active Mobile IP framework is currently implemented over the Linux operating system. The programmable framework is applied to the Mobile IP agent nodes namely, the mobile node, foreign agent, home agent and correspondent node. To demonstrate the ease of designing and deploying new mobile services, this paper describes the setup of an experiment to implement an active route optimization service. 

Towards Sensor Database Systems

Authors: Philippe Bonnet, Johannes Gehrke, Praveen Seshadri

Abstract: Sensor networks are being widely deployed for measurement, detection and surveillance  applications. In these new applications, users issue long-running queries over a combination  of stored data and sensor data. Most existing applications rely on a centralized system  for collecting sensor data. These systems lack flexibility because data is extracted in  a predefined way; also, they do not scale to a large number of devices because large  volumes of raw data are transferred regardless of the queries that are submitted. In our  new concept of sensor database system, queries dictate which data are extracted from the  sensors. In this paper, we define a model for sensor databases. Stored data are  represented as relations while sensor data are represented as time series. Each  long-running query formulated over a sensor database defines a persistent view, which  is maintained during a given time interval. We also describe the design and implementation  of the COUGAR sensor database system. We detail how sensor data are represented and how  sensor queries are formulated and evaluated.

Storage and Retrieval of Moving Objects

Authors:  Hae Don Chon, Divyakant Agrawal, Amr El Abbadi

Abstract: Information management for advanced transportation systems is significantly  complex, since it requires maintaining dynamically changing information  associated with moving objects.  Updating current locations of moving objects every time they move is not  a realistic solution. In this paper, we investigate the problem and  provide a data model with which we can store, index, and retrieve  future locations of moving objects in an efficient manner.  Each moving object has four independent variables which allow us to predict  its future location:  a starting location, a destination, a starting time, and an initial velocity.  To understand the underlying complexity of the problem, we investigate and  categorize the configurations where only one or two variables can vary.  Based on that understanding, we choose a configuration which is to some extent  restrictive, but still can be used in a wide variety of realistic settings.  After developing a data model, we conduct performance study and show  that our model has much less overhead in processing range queries compared to  other proposed approaches.

ENERGY-EFFICIENT TRANSACTION MANAGEMENT FOR REAL-TIME MOBILE DATABASES  IN AD-HOC NETWORK ENVIRONMENTS

Authors: Le Gruenwald  Shankar M. Banik

Abstract: In an ad-hoc mobile network architecture, all mobile hosts (MHs) are connected with each other through  a wireless network that has a frequently changing topology. This type of architecture is used in many  applications such as battlefields and disaster recovery where it is difficult or not feasible to depend  on a static wired communication infrastructure. These applications are usually time-critical where many  of their transactions must not only be executed correctly but also within their deadlines. In addition,  the MHs in this environment are not connected to unlimited power supplies and may store data that can be  shared by other MHs. Existing mobile database transaction management techniques do not consider the ad-hoc  network characteristics, real-time constraints, and energy limitation. This paper reviews these existing  techniques, identifies issues that need to be addressed in  this new environment, and propose approaches for solutions.

Increasing Concurrency of Transactions  using Delayed Certification in Mobile DBMSs

Authors: IlYoung Chung and Chong-Sun Hwang

Abstract:   In mobile client-server database systems, caching of frequently accessed  data is an important technique that will reduce the contention on the  narrow bandwidth wireless channel. As the server in mobile environments  may not have any information about the state of its clients' cache(stateless  server), using broadcasting approach to transmit the list of updated data to  numerous concurrent mobile clients is an attractive approach. In this paper,  a new concurrency control protocol is proposed to reduce aborts of  concurrent transactions. The proposed protocol can improve the throughput of  transactions by increasing the number of transactions which can be committed  by the server during the same broadcasting interval. For this, with the  proposed protocol, the server delays the certification of transactions  until the next broadcasting point. The protocol adopts adaptive broadcasting  as the way of sending invalidation reports, which shows stable performance  by choosing appropriate broadcasting strategy between synchronous and  asynchronous broadcastings. We study the performance of the proposed  protocol by means of simulation experiments.

Optimized Scheduling on Broadcast Disks

Authors: Jeong-Hyon Hwang(contact author)  SungHo Cho  Chong-Sun Hwang

Abstracts:   Since the advent of wireless networks and portable computing  devices, push-based data delivery has been discussed as an  attractive communication framework for wireless environments. This  paper focuses on the way of scheduling that leads to the minimum  access delay for a hierarchical push-based data broadcast  mechanism. This mechanism, called ``Broadcast Disks'', partitions  data items into a number of logical disks spinning at different  speeds and superimposes the disks on a single broadcast channel.  In this paper, we mathematically model the Broadcast Disks program  generation and suggest concrete design principles for deciding (a)  how many disks to use, (b) how to segment data items  into disks based on the user access patterns, and (c) how to  determine the relative spinning speeds for disks in order to  minimize the average access delay. In addition, we present  our simulation study that substantiates the optimality of the  suggested algorithms with detailed analyses.

Performance Modeling of Layered-Data Delivery for Mobile Users  through Broadcast / On-Demand Hybrid Communication

Authors:  Kenya Sato, Soichi Hasegawa, Shigeaki Tagashira,  Keizo Saisho, and Akira Fukuda

Abstract: The rapidly expanding technology of portable personalized computing  devices and wireless data networks has recently given mobile clients  the capability of accessing multimedia data through personal cellular  phone networks. The problems encountered with the networks, which we  refer to as the on-demand network, are bandwidth and scalability.  Meanwhile, digital satellite/terrestrial data broadcasting services  are available or will become available in the near future. Although  broadcast data delivery is scalable and has wide bandwidth, the  drawback of broadcast methods requires the clients to wait for the  required data to appear.   In this paper, we propose an efficient layered-data delivery system  through multiple heterogeneous networks, which are on-demand and  broadcast. Layered data are composed of (1) common parts available or  useful to many clients, and (2) personalized parts for individual  clients. The system sends the personalized parts through on-demand  networks and the common parts through broadcast networks. A  performance model of the system consisting of a client and two servers  (broadcast and on-demand) connected to two Ethernet segments is also  implemented and evaluated. The evaluation results show that our  proposed system works effectively under certain conditions.

iSwitch, New Mechanism of E-Commerce Service

Speaker: Zhu Chaoxiang, Assistant of General Manager of Reaserch & Development Center of Liming

Abstract:  iSwitch Corporation(Liming Network Systems) is a high technology company engaged in the design, sale and service of its main product, the iSwitch e-commerce platform.  The original concept and design of the e-commerce platform were entirely conceived by Liming Network Systems Co., a principal subsidiary of iSwitch with operations in Shenzhen, China.  Liming was a pioneer in China's IT industry, and it has been credited with the design and implementation of the inaugural networks used in the Shenzhen and Shanghai stock exchanges in the early 90s.
In 1997, the concept of iSwitch was born.  A commercial product was launched in March 2000, after successful proof of concept in consultation with some of world's largest IT manufacturers and telecom operators.  Generally speaking, iSwitch allows service providers to provision for mobile and other new services without having to pay for the high costs of start up and maintenance of these services.  All the application development work is being done by iSwitch and resides at the platform.  Service providers will only need to pay a nominal fee for hook-up to the platform, plus other fees that can be arranged based on transaction volume.  When a user connects to iSwitch, he or she can immediately access the favorite applications, such as mobile stock trading.  At the same time, because the platform is also connected to many other applications, the same user can also access these other applications as well.  In this context, iSwitch can be viewed as a natural e-commerce market place, where it is convenient for users and service providers to meet and conduct transactions in almost real time.  With application driving usage and vise versa, the effect could be quite explosive.


CC/PP For Content Negotiation and Contextualization

Authors: LALITHA SURYANARAYANA, JOHAN HJELM

Speaker: Lalitha Suryanarayana is a Senior Member of Technical Staff at SBC Technology Resources, the applied R&D arm of SBC Communications, a global communications leader. Her research interests include defining network and device agnostic architectures for interactive and collaborative applications for wireless and Internet. She is an active contributor to the CC/PP working group in the World Wide Web Consortium, and participates in the WAP-W3C Coordination efforts. As an Acting Chair, she is currently also leading the User Agent Profile specifications effort in the WAP Forum. Recently, she has co-authored a popular book titled "WAP - Writing Applications for the Mobile Internet

Abstract:The proliferation of Internet capable devices supporting a variety of user-interface paradigms and modalities brings forth the challenge of rendering content in a suitable format that is tailored to the device characteristics and user preferences. In order to enable such content customization, there is a need for a standardized capabilities-and-content negotiation mechanism that will allow clients accessing the web to assert their capabilities to the server serving the content. This paper discusses Composite Capabilities/ Preferences Profile (CC/PP), a protocol-independent extensible framework that can be used for communicating any meta data information such as device and document profiles. We describe WAP User Agent Profiles as a use case, where CC/PP is a core technology for enabling the convergence of the mobile web with the classic web. We also recommend the framework for conveying contextualized information to enable context based environmental adaptation in the future.

On-line service adaptation for mobile and fixed terminal devices

Authors:  Jari Korva (jari.korva@vtt.fi) - contact author,  Johan Plomp (johan.plomp@vtt.fi), and  Petri Maatta (petri.maatta@vtt.fi)

Abstract:   This paper reports on the dynamic adaptation of multimedia services  for both mobile and fixed terminal devices. The adaptation is done based  on the device features and includes both the adaptation of the  presentation format (e.g. HTML, WML, SMS, E-mail and speech driven  browsers) as well as the multimedia contents. The services are defined  in XHTML with some extensions. In this paper, we mainly focus on the  considerations involved in the development of the adaptation methodology.  The architecture of the system is also briefly described. The research is  part of the Princess project, a joint project of Oulu University and  VTT Electronics.

A Secure Context Service for Pervasive Computing

Authors: J Smith Doss, Maria Ebling, Guerney Hunt, Renee Kovales,
Hui Lei, Gregory Stewart, Robert Sundstrom

Speaker: Dr. Hui Lei (Research Staff Member, IBM T. J. Watson Research Center)

Hui Lei is a member of the research staff at IBM's T. J. Watson Research Center. His research interests include pervasive computing, data management, and distributed systems. He holds a M.S. in Computer Science from Courant Institute, New York University, and a Ph.D. in Computer Science from Columbia University.

Abstract: Technology trends are making an explosive amount of information accessible to users anytime and anywhere. However, user mind-share devoted to computing concerns is unlikely to increase. The problem of limited human attention may be alleviated by obtaining and exploiting information on the context of computing. Context awareness brings a number of benefits. It enables targeted and personalized access by delivering the right information to the right place and at the right time. It allows user intention to be inferred and user distraction reduced. It supports the dynamic discovery of useful resources to relieve the constraints in a pervasive computing environment. When a future context is anticipated, it may also be possible to prefetch information and thus improve user-perceived access latency.

The potential wide applicability and copiousness of contextual information
suggest the need for an independent context service. Such a context service should provide an extensible framework for gathering and supplying a large variety of environmental aspects, a standard API through which applications can submit requests for desired information, and a global data model that provides structure for accessing and reasoning about contexts. Since contextual information is inherently private and sensitive, a context service also needs to provide a mechanism that gives information owners, not service operators, complete control of who may access the information.
Needless to say, the access control mechanism must be user-friendly in order to be effective.

We have been experimenting with a prototype context service to address the above challenges. Our prototype uses a form metaphor for the exchange of contextual information. Each form embodies a collection of attributes related to some aspect of the physical or virtual environment. An application requests information by partially filling out a form and asking the context service to return the completed and matching forms. The application also specifies what action the service should take when no matching information is immediately available, where the options are block, return, and set a callback. Access control is at the granularity of form fields and based on the user groups defined by the information owner. Internally, the context service includes a configurable set of context drivers, each of which handles one form type. A mediator component dispatches incoming requests to the responsible drivers. Among the context
drivers that have been written are one that derives users' physical whereabouts and activities from their respective calendar entries, and one that tracks users' instant messaging on-line status.


A Map-Based Hoarding Mechanism for Location-Dependent Information Systems

Authors: Uwe Kubach and Kurt Rothermel

Abstract:  In mobile environments, information systems are often accessed  through wireless WANs. Thus the users often have to cope with  difficulties such as low bandwidth, high delay, and frequent  disconnections. Hoarding is an efficient method to overcome these  difficulties. The idea is to transfer information, which is probably  needed by the user in the near future, in advance, so that it is  already stored on the user's mobile device when it is actually  accessed. In this paper, we present a hoarding mechanism that is  location-aware, i.e.\ it uses information about the users'  geographic locations in order to predict the information items they  will access. The mechanism is based on the use of wireless LANs,  so-called info-stations. These info-stations are used to transfer  the information items that have been selected for hoarding to the  users' mobile devices. In contrast to existing location-aware  hoarding approaches, our mechanism is more flexible. Therefore, we  claim that it can be applied in any location-dependent information  system. Its flexibility allows our mechanism to use different  sources of information about the users' locations and even  additional, new sources can be integrated easily.

Multicast Micro-mobility Management

Authors: Vincent Magret, Vinod Kumar Choyi

Abstract: Mobile IP [RFC2002] offers a neat support to mobile users, indeed they can roam from one network to another quite easily. Although the concept suffers from a major drawback when the user's movement profile imposes a high frequency of handoffs. Mobile IP requires the mobile node to inform its home agent of its new location every time it changes its point of attachment. The concept, which is sometime referred as macro-mobility is not suitable when it is intended that there will be frequent handoffs. The term micro-mobility defines an extension to the base concept, by hiding the location of the mobile node to the home agent. The mobile node's location is kept as a local matter of the wireless domain infrastructure visited. This document presents a new protocol designs to handle micro-mobility.

Dynamic remote update adapting wireless network connection states

Authors: Sung Hun Nam(contact author), Chong Sun Hwang

Abstracts: To maintain cache consistency at mobile clients, server broadcasts updated information. The broadcasting information is nvalidation or propagation. However, invalidation of frequently accessed data causes many cache requests. Although propagation can reduce cache requests, it is easily damaged by outer interference under unstable connection state of wireless network. The larger message is, the higher probability of damage. To resolve these problems, we suggest remote update algorithm that dynamically selects invalidation or propagation message according to wireless network connection states. It broadcasts propagation message for frequently accessed data in order to reduce cache request under stable connection state. Under unstable connection states, it only broadcasts invalidation message to reduce the probability of damaging message. Consequently, under any connection states, our scheme follows superior scheme between invalidation and propagation.

ADAPTIVE DELIVERY OF MULTIMEDIA DATA IN HETEROGENEOUS AND MOBILE ENVIRONMENTS

Authors: Mqhele Nzama, Alexander Ng and Arkady Zaslavsky

Abstract: This paper discusses the sources of variability in heterogeneous and mobile networks that make it difficult for traditional applications to work properly. In addition we investigate the problems associated with delivering multimedia content to clients with varying capabilities. We present adaptivity as a tool to extend the lifetime of critical applications as well as a technique to meet client variability. To this end we have developed a prototype that reduces dependency on scarce resources experienced in mobile environments. The adaptation space framework is used to provide a flexible and consistent design strategy.

Designing Electronic Forms in Web Applications: Integration of Web Components

Authors: Soroush Sedaghat

Abstract: This paper suggests an innovative and practical approach for designing electronic forms (e-forms) to assist user-friendly collection of accurate data in Web environments.

Hashing Moving Objects

Authors: Zhexuan Song, Nick Roussopoulos

Abstract: In many real-life applications, the objects are both spatial and temporal referenced. The objects which continuously change their location are called moving objects. With the development of wireless communication and positioning technology, it becomes necessary to store and index moving objects in database. Due to the complexity of the problem, many pure spatial index structures are unable to handle large volume of moving objects. In this paper, we proposed a new idea based on hashing technique: using buckets to hold moving objects. The database does not make any change until an object moves into a new bucket. Therefore, the database update cost is greatly reduced. Then, we extended the existing system structure by inserting a filter layer between the position information collectors and the database and we presented four different methods based on the new system structure. Performance experiments were performed to evaluate different aspects of our indexing techniques, and the conclusions are included in the paper.

Quasi-Consistency and Caching with Broadcast Disks

Authors: Rashmi Srinivasa, Sang H. Son

Abstract: The challenges ensuing from the asymmetric communication capabilities of a mobile environment have led to an increased interest in broadcast-based data dissemination. Among the concurrency control techniques proposed for transactional clients in broadcast environments, Broadcast Concurrency Control using Timestamp Interval (BCC-TI) has been demonstrated to be more efficient than a simple adaptation of optimistic concurrency control with forward validation. In this paper, we explore two different ways of improving concurrency control performance in broadcast environments - caching and a weaker consistency criterion. We add client-side caching to BCC-TI, and demonstrate that caching causes an improvement in the average response time of a mobile transaction. We propose a new concurrency control technique called Quasi-TI that enforces a weaker correctness criterion called quasi-consistency. Quasi-TI is an attractive concurrency control technique for applications for which serializability is unnecessary and too expensive to enforce. We introduce a new caching algorithm called PIT, and study the effects of both a traditional caching algorithm and of the PIT caching algorithm, on the performance of Quasi-TI. Through simulation experiments, we demonstrate that the proposed techniques achieve good performance for workloads with certain characteristics.

Optimistic Scheduling Algorithm for Mobile Transactions based on Reordering

Author: SungSuk Kim, Chong-Sun Hwang, HeonChang Yu and SangKeun Lee

Abstract: With the advances in wireless communication and its related technologies, there are a lot of research efforts which intend to utilize mobile computers as a processing unit, rather than just a terminal. That is, the algorithms with which mobile users can execute their jobs have been developed. In this paper, we propose transaction processing algorithms in the broadcast environment. The server periodically broadcasts all the data objects. We take an optimistic approach for mobile transactions because (a) it needs a small number of messages for maintaining transactional consistency, and (b) it can make use of broadcasting facilities from the servers. However, the more the data conflicts occur, the more mobile transactions are aborted due to optimistic execution. Therefore, we also use a reordering technique to reduce the number of aborted transactions; that is, whenever conflicts are found from broadcast information, the system try to determine the operation orders as far as the decision may not violate transactional consistency, not just aborting the mobile transactions unconditionally. By using reordering technique, mobile computers can process both read-only transaction and update transaction while maintain the serializability as the correctness criterion for transaction processing. The proposed algorithms- O-Post algorithm for update transaction and O-Pre algorithm for read-only transaction -do not need much information from the server to maintain the consistency. Finally, we also evaluate the performance behavior through simulation study.


 

Design and Implementation of an Information Announcement Toolkit for Mobile Computers

Authors: S. Tagashira, K. Saisho, and A. Fukuda

Abstract: An information announcement system from mobile computers has been proposed. Announcing information from mobile computers has problems unlike that from stationary computers. Stable services from a mobile computer cannot be provided because of the problems. We discuss the problems and the facilities required to address them. This paper proposes an information announcement system which can realize the facilities, and a software toolkit that supports the construction of the system. The proposed system has the following features: in order to provide stable services from mobile computers, the system provides a toolkit which can address the problems in mobile environments, and the toolkit allows a wide variety of legacy network applications designed for stationary environments to be adapted to mobile environments easily and smoothly. This paper designs and implements the toolkit. Moreover, we illustrate that two applications, a web system and an Internet TV telephone system, are constructed as examples, and the applications can be adapted to the mobile environment with little programming overhead by using the toolkit.

Serving Spatial Location Information over the Internet

Authors: Haitao Tang, Mari Korkea-aho, Jose Costa-Requena, Jussi Ruutu

Speaker: Haitao Tang (haitao.tang@nokia.com) is an R&D staff member in Nokia Research Center (Helsinki). He received his M.S. degree in communication and electronic systems in 1986, and his Doctor of Science degree in computer science and engineering in 1998. He has continuously worked in IP networking and applications since 1992.

Nokia is the world leader in mobile communications. Backed by its experience, innovation, user-friendliness and secure solutions, the company has become the leading supplier of mobile phones and a leading supplier of mobile, fixed and IP networks. By adding mobility to the Internet Nokia creates new opportunities for companies and further enriches the daily lives of people. Nokia is one of the most broadly held companies in the world with listings on six major exchanges.

Abstract: This paper proposes a concept of serving spatial location information over IP networks. It clarifies and explores the requirements and solutions to realize the concept. The crucial issues elaborated with solutions are: definitions of target and its location, its naming requirements and mechanisms, its roaming among location servers, location request routing, acquiring spatial location information in a reliable, secure, and scalable manner over IP networks. Recently, issues of location-based applications have been raised in the IP community. This paper contributes to a cutting edge effort for supporting such applications over IP networks.

High Performance Data Broadcasting: A Comprehensive System's Perspective

Authors: P. Triantafillou, R. Harpantidou, and M. Paterakis

Abstract: Broadcast scheduling algorithms have received a lot of attention recently, since they are important for supporting mobile/ubiquitous computing. However, a comprehensive system's perspective towards the development of high performance broadcast servers is very much lacking. With this paper we attempt to fill this gap. We contribute four novel scheduling algorithms that ensure the proper interplay between broadcast and disk scheduling in order to attain high performance. We also examine a cache management scheme, which enjoys superior performance. We study comprehensively the performance of the broadcast server, as it consists of the broadcast scheduling, the disk scheduling, and the cache management algorithms. Our results show that the contributed algorithms outperform the algorithms, which currently define the state of the art. Furthermore, one of our algorithms is shown to enjoy considerably higher performance, under all values of the problem and system parameters (such as the skew of access distributions, the system load, the data object sizes, cache- and disk-intensive workloads, etc.). An important conclusion of this study is that broadcast scheduling algorithms have only a small effect on the overall broadcast system performance, a fact that necessitates the refocusing of related research.

Event Engine for Adaptive Mobile Computing

Authors: Shiow-yang Wu and H. S. Cinatit Chao

Abstract: To cope with the highly resource constrained and dynamically changing mobile computing environment, we propose an architecture which employs an active event engine to detect current resource and environment status, inform registered applications about status changes, and provide a suite of actions for application adaptation. Preliminary implementation and evaluation results demonstrate that the event engine can successfully detect the registered events and invoke application specified actions to bring the system to a desired state.

Effects and Performance of Content Negotiation Based on CC/PP

Authors: Kinuko Yasuda, Takuya Asada and Tatsuya Hagino

Abstract: We describe our investigation of the effectiveness of Web content negotiation using CC/PP. CC/PP is a proposed specification for user-side content negotiation framework to comply with various clients; with respect to user-agent capabilities and user preferences. CC/PP is based on common technologies such as XML and HTTP extension and is expected to provide a generic content negotiation solution for both existing Web clients and new types of ones such as Web-capable cellular phones. However, currently CC/PP has no implementation and its performance has not been known. We have implemented a mobile Web browser which is capable of CC/PP to verify the performance of its content negotiation. We also implemented an experimental CC/PP proxy which converts Web contents to investigate CC/PP's power on intermediate nodes. In order to examine the optimal settings of CC/PP, we compared the real time performance of CC/PP with inline encoding and with indirect reference, with profile cache and without cache, and with normal profile-diffs and with abbreviated profile-diffs. We also investigate whether content conversion using CC/PP enhances the network performance despite CC/PP overhead caused by its verbosity. The result shows that the use of indirect reference and abbreviating profile-diffs have dramatic effects on elapsed time improvements when the connection between the client and the proxy is as narrow as cellular phones. On the other hand, when the connection is wider than that, the use of indirect reference does not improve performance. We also demonstrate that caching profile at the proxy results few improvements. For all our tests, the retrieval of Web contents with content conversion using CC/PP outperformed the normal retrieval without CC/PP under all network environments tested. The result confirms that CC/PP is an effective solution for general content conversion.

Multi-resolution Web Document Browsing ina Distributed Agent Environment

Authors: Stanley Yau, Hong Va Leong, Antonio Si.

Abstract: A mobile environment is characterized by low communication bandwidth and poor network connectivity. Accessing web documents in a mobile environment is inefficiency and ineffective. We have presented a multi-resolution transmission and browsing mechanism for web documents, in which a web document is partitioned into multiple units. Units with higher information content will be transmitted earlier. This enables a mobile user to explore the more content-bearing portion of the document and terminate the transmission of an irrelevant document sooner. This provides a means to deal with the low bandwidth problem. In this paper, we employ a mobile agent model to combat the problem of poor network connectivity. A mobile agent represents a software proxy to a mobile user. It has the capability to migrate to a base station that is currently serving a mobile user. This establishes a virtual connection to the user. The mobile user could assume that the connection seldom gets broken and thus, does not need to concern about the connectivity issue. The agent, acting on behalf of the user, travels along the wired network to carry out its tasks and collect results, which are then returned to the user at the end of the itinerary of the agent. We have integrated the multi-resolution transmission mechanism with the mobile agent model into a prototype of a mobile web browser. The prototype is embedded within a more general framework of Distributed Agent Environment (DAE), which supports mobile agent in a mobile environment. We have conducted experimental study, comparing performance between conventional mobile client/server model and mobile agent model in accessing a database server through both wireless and wired networks.

Soft Ad-Hoc Networking

Authors: Tao Zhang, and Wai Chen

Speaker: Dr. Tao Zhang is Director of Mobile Packet Networking Research at Telcordia Technologies (formerly Bellcore), New Jersey, USA. Dr. Zhang has been leading and conducting research, development and consulting on mobile wireless Internet, wireline Internet, WDM and ATM networks. Dr. Zhang has 11 pending U.S. patents in several critical areas of mobile packet networking: soft handoff in all-IP (Internet Protocol) wireless networks, resource management, dynamic allocation of IP addresses to mobile stations, and the design of IP-based wireless base stations. Dr. Zhang is the recipient of the Telcordia CEO Award that recognizes the Company's most exceptional teams and individuals who have achieved a significant business success. Before joining Telcordia (then Bellcore) in 1995, Dr. Zhang was a strategic network designer for major financial services companies including Citibank, Dow Jones and Lehman Brothers, where he was responsible for designing advanced networks and software systems for global financial services. Dr. Zhang received his Ph.D. degree in computer engineering from the University of Massachusetts Amherst in 1993.

Telcordia Technologies was formerly known as Bellcore, which served as a center for technological innovation and expertise to the Bell operating companies since 1984. Telcordia holds hundreds of patents, including key patents for broadband data communications technologies like SONET, ADSL, AIN, ATM, ISDN, Frame Relay, SMDS, and video-on-demand. Eighty percent of the U.S. telecommunications network depends on software invented, developed, implemented, or maintained by Telcordia. Today, Telcordia conducts research, provides software and consulting for the telecommunications industry worldwide.

Abstract: Existing ad-hoc routing mechanisms require nodes to maintain network topologies, large routing tables, and/or end-to-end paths. Consequently, they have limited scalability and face a dilemma between scalability and performance. This paper proposes a new approach for ad-hoc networking - Soft Ad-Hoc Networks - that eliminates the need for nodes to maintain network topologies, routing tables or end-to-end paths. This paper proves that 1) soft networks are feasible, i.e., it is virtually assured that packets will find their ways to their destinations; 2) soft networks have less routing and transport overhead than the existing ad-hoc routing mechanisms under many practical network conditions; and 3) soft networks could achieve the best possible end-to-end delay performance among all known ad-hoc networking approaches with little adverse impact on its high scalability.

Location Based Services with Oracle9i AS Wireless Edition

Speaker: Mr. Ho was previously a member of Oracle's database development group where he was responsible for the database index code for Oracle version 6, 7, and 8. He has authored several papers and courses dealing with Oracle server performance and management. He has also represented Oracle Corporation at the Transaction Processing Performance Council's online transaction processing benchmark committee (TPC-C). Mr. Ho is currently responsible for the deployment of Oracle's Mobile and Embedded Products throughout the Asia-Pacific region. Mr. Ho holds degrees in computer science from U.C. Berkeley and Stanford University and has been awarded several U.S. patents for various database innovations.

Abstract:

Open Platforms for Mobile Internet Applications

Speaker: Samuel Li, Senior Manager, Nokia China

Abstract: Nokia has introduced Nokia mPlatform solution, an open platform including the standard Application Interface (AI) for mobile internet application developers and mobile operators to develop and implement mobile Internet services. An open application interface brings several significant advantages: it enables seamless services because applications are integrated to work together; Applications can be created within various developer communities and services can be easily mixed and matched to be market and user segment specific with both local and general content; Open application interfaces also utilizes the network assets, such as location, authentication and billing information. With Nokia mPlatform solution as an enabling layers, mobile operators and service provider can now start to build a trusted position with their mobile Internet portals and tailor news services according to market and consumer demands. The popular services extends to information on demand, entertainment, mobile commerce (mobile banking, stocking, ticketing, lottery), enterprise services, and personal trust services. To further boost mobile Internet applications and services, Nokia has initiated and managed Nokia Artuse Developers Programs (NADP) to help developers work together with mobile operators. Operating globally, the NADP focuses on boosting the development of attractive value-added services on standard technologies, such as WAP. This program suits any application developer or content provider/packager with the ambition to develop applications and services relating to mobile Internet and messaging. In addition to WAP, this program supports messaging technologies, such as Smart Messaging and Computer Interface for Messaging Distribution (CIMD). For further information, please visit http://www.forum.nokia.com to join NADP program.

Universal Tuner: Exploring the Role of Mobile Streaming Video
In Pervasive Computing Scenarios

Authors: Dr. Richard Han (Research Staff Member,IBM Thomas J. Watson Research Center)

Speaker: Richard Han (rhan@watson.ibm.com) is a Research Staff Member in the pervasive multimedia / mobile applications group at the IBM T.J. Watson Research Center. He received his B.S. degree in electrical engineering with distinction from Stanford University in 1989, and his Ph.D. degree in electrical engineering from the University of California at Berkeley in 1997. He has continuously conducted research in mobile multimedia networking since 1994, when he contributed to Berkeley's seminal InfoPad
wireless multimedia project. His research interests include distributed mobile applications and wireless multimedia coding.

Abstract: This talk will focus on our exploration of the role of mobile streaming video in pervasive computing scenarios. Three important trends are emerging: a proliferation of pervasive computing devices; wireless connectivity to the Internet and Web; and streaming packet video over the Internet. We believe that these trends will converge, resulting in a host of new mobile applications that take advantage of streaming video
to wireless handhelds in a variety of scenarios. Questions of interest to the pervasive computing community include:
(1) How will people use pervasive access to video anytime, anywhere?
(2) What kind of infrastructure is needed to support such applications?

Moving Objects Databases: Issues and Possible Solutions

Speaker: Ouri Wolfson's main research interests are in database systems, distributed
systems, transaction processing, and mobile computing. He received his B.A. degree in mathematics, and his Ph.D. degree in computer science from Courant Institute of Mathematical Sciences, New York University, in 1984. He is currently a Professor in the Department of Electrical Engineering and Computer Science at the University of Illinois at Chicago, where he directs the Databases and Mobile Computing Laboratory. He is also a consultant to Argonne National Laboratory, to the US Army Research Laboratories, and to the Center of Excellence in Space Data and Information Sciences at NASA. Before joining the University of Illinois he has been on the computer science faculty at the Technion and Columbia University, and he has been a Member of Technical Staff at Bell Laboratories.

Ouri Wolfson authored over seventy publications in leading journals and conference proceedings. He is an editor of the ACM/URSI/Baltzer Wireless Networks Journal, a Member of the ACM SIGMOD Digital Review Editorial Board and a guest editor of the ACM/Baltzer Journal on Special Topics in Mobile Networks. From 1991 to 1996 he served as a National Lecturer for the Association of Computing Machinery professional society. He participated in numerous conferences (including ACM-SIGMOD, VLDB, PODS, ICDE, NGITS, ICDCS, MOBIDATA, DOOD, SSD, GIS, PDIS, CIKM) as a program committee member, keynote speaker, session chairman, and panelist. Most recently he was the program committee co-chair of the First International Workshop on Satellite-based Information Systems (Wosbis), and the general co-chair of the Second
International Workshop on the same topic. He was also the General co-Chairman of the IEEE Knowledge and Data Engineering Exchange Workshop, and he serves on the Advisory Committee of the NSF Center of Research Excellence in Science and Technology, at Florida A&M University. His work has been funded by the National Science Foundation, Air Force Office of Scientific Research, Defense Advanced Research Projects Agency, NATO, US Army, the New York State Science and Technology Foundation, Hughes Research Laboratories, and Informix Co.

Abstract: Consider applications of a database that models information about moving
objects and their location. For example, given a database representing the location of taxi-cabs, a typical query may be: retrieve the free cabs that are currently within 1 mile of a customer at 33 N. Michigan Ave.. Military applications utilizing moving objects databases arise in the context of the digital battlefield, and civilian ones arise in transportation systems and in systems that track mobile computers for providing context
awareness.

Currently, moving objects database applications are being developed in an ad hoc fashion. Database Management System (DBMS) technology provides a potential foundation upon which to build these applications, however, there is a critical set of needed capabilities that are lacking in existing DBMS's. These include support for continuously changing data, for integrated spatial and temporal information, and for uncertainty management. The objective of our Databases fOr MovINg Objects (DOMINO) project is to build an envelope containing these capabilities on top of existing DBMS's. In this talk I will describe the problems addressed by the project, and our proposed solutions.

Toward a Mobile, Multimedia Lifestyle: A Glimpse Inside Microsoft Research China

Abstract: As the types of mobile devices proliferate and wireless transmission bandwidth increase, it will become possible to access multimedia content on mobile devices from anywhere and at any time. There are several technical issues related to this type of scenarios. They are: 1) transmission of multimedia content; 2) organization of multimedia content; 3) accessing multimedia content on mobile devices. In this talk, I will describe ongoing research efforts at Microsoft Research, China in these three areas and demonstrate prototypes which illustrate our research results thus far.

Speaker: Eric Chang joined Microsoft Research, China in July, 1999 and is the research manager of the speech group. Eric was one of the founding members of the Research group at Nuance Communications, a pioneer in natural speech interface software for telecommunication systems. While at Nuance, Eric worked on various projects involving confidence score generation, acoustic modeling, and robust speech detection. He also led the technical effort to develop the Japanese version of the Nuance product. This project led to the world's first deployed Japanese natural language speech recognition system.

Eric has also developed speech recognition algorithms at M.I.T. Lincoln Laboratory, invented a new circuit optimization technique at Toshiba ULSI Research Center, and conducted pattern recognition research at General Electric Corporate Research and Development Center.

Eric graduated from M.I.T. in 1995 with a Ph.D. degree, in 1990 with Master and Bachelor degrees, all in the field of electrical engineering and computer science. While at M.I.T., he was inducted into the honorary societies Tau Beta Pi and Sigma Xi.

Eric has published papers in the fields of speech recognition, neural networks, and genetic algorithms in various journals and conferences. He is the author of several granted and pending patents. His research interests are spoken language understanding, machine learning, and signal processing.

Microsoft Research, China was founded to establish a presence for Microsoft in the world's most populous country and fastest-growing economy. Microsoft Research, China's ambition is to become a world-class computer science laboratory in Asia and to attract the most talented young Chinese researchers to work in the lab. Dr. Ya-Qin Zhang, a world-renowned scientist and business executive, currently heads up Microsoft Research China as the Managing Director. The former managing director, Dr. Kai-Fu Lee, an internationally-acclaimed scientist and business leader, is being promoted to vice president at Microsoft's main headquarters in Redmond where he will focus on developing the user interface of Microsoft's next generation of software and services, Microsoft. Net. Since its founding on November 5, 1998 Microsoft Research, China has attracted nearly 70 technical talents and over 200 visiting scientists and students from China and around the world. MSR China has set an ambitious research agenda highlighting three areas:

Location-Targeted Wireless Advertising

Authors: Hwa-Pyng Tzeng (Director, Network Management Technologies Department
Verizon Laboratories)

Speaker: Hwa-Pyng Tzeng (htzeng@gte.com) is Director of the Network Management Technologies Department in Verizon Laboratories, responsible for systems and solutions that give a competitive advantage to the service quality and network operations efficiency of Verizon and affiliates. He has applied advanced software technologies to emerging telecommunication network management challenges and create industry-leading systems to manage network faults, performance, and service level agreements for productivity and market responsiveness. He received his B.S. degree from National Taiwan University, Taiwan, and the M.S. degree from The University of Massachusetts at Amherst. He has 15 years of IT development and management experiences. Before joining Verison Laboratories (formally GTE Labs), he has worked for various companies such as Peritus Software Services, Inc., Bull Information Systems, Inc., and Parametric Technology, Inc.

Abstract: This talk introduces a system intended to help advertisers to deliver their advertisement to mobile users dynamically and effectively. Location information of individual mobile users will be continuously collected and used to drive the advertisement dispatch. Customer relationship management tools can be integrated with the system as important business analysis assistance to discover and verify targeted advertisement rules. The advertising engine uses these rules to identify the most promising prospective customers for a dvertisers and to deliver the advertisement to the selected customers in a timely fashion.  The benefit of using this system is three-fold: as advertisers, their advertisements are guaranteed to deliver to potential customers at the right time and through the right channel; from the wireless service provider's point of view, providing this value-added service will help to improve customer loyalty and reduce churn rate; as mobile phone customers, they will enjoy highly targeted, location and time sensitive advertisements whenever they want them. A prototype of the location-targeted advertisement system will be demonstrated in this presentation.