research

DAYS has been conceptualized as a way to disseminate high volume information to a massive number of users in mobile environments. As the number of users going mobile continues to increase at phenomenal rate, it requires that one can continue to access data anytime and anywhere. Besides, there are various types of data we need to access frequently in our daily lives at different times during the day. One always need the traffic information in the morning when going out. During the move one may need the traffic information for a particular route so that he could divert himself if the current route is busy. He may also need to know about the current information regarding stocks. In any part of the day one may need to know the weather information for a particular location. In the evening or during the weekend, one may wish to access entertainment information like location of hotels, current happenings in the city or remote place, etc. Along with all these data requirement which is mostly read only, one may also require to add and update data while on the move. Most prominent among them are monetary transactions of banks. But the ratio of read-only data to write-only data is quite large. There can be two approaches for accessing read-only data. One can initiate a request to the server for the required data and wait until the request is served. There are several disadvantages in this approach. The request may not reach the server properly as it can get blocked in the queue of request. This can significantly delay the processing and subsequent arrival of data. Moreover, as the number of requests can grow exponentially, there is a lot of chance that the request queue can overflow leading to subsequent dropping of the data request. But since all these requests may need to access similar kind of data, it would be feasible to broadcast them to the users in periodic intervals rather than cater to individual request which can eventually lead to bottleneck for bandwidth. DAYS architecture thus intends to develop satellite based high volume information dissemination systems which will include both the push and pull technology to deliver data.


INFOSPACE: AN ADAPTIVE AND HYBRID BROADCAST BASED PUBLIC DATA  DISSEMINATION SYSTEM

Data dissemination through wireless channels has become a very effective way of providing required information to users. Almost all earlier works on broadcast have focused either on pure push or pull based and little attention has been given to the combined approach. There has been some significant work on data caching using broadcast to minimize latency. We believe that the latency time can be further reduced by the use of data staging and by caching data at different levels. This is our motivation and in this work we propose an innovative cellular network based public data dissemination strategy based on a new architecture. In our scheme we use an adaptive push and pull based approach where push data dynamically changes to pull data and pull data changes to push data to meet users' requirements. We show that our approach effectively utilizes limited bandwidth and frequently accessed data is managed at low latency.

 MOBILE WEB SERVICES

    WEB BAZAAR: A DATA STAGING AND WIRELESS BROADCAST BASED WEB SERVICE SYSTEM

With the advent of Internet and E-commerce, the information management paradigm has shifted. Thus, instead of legacy systems now web is used as the primary interface to manage business over the Internet and has become indispensable for disseminating information to the general public. Organizations no longer limit the scope of the web to a repository rather they use it as a powerful communication tool and also as their showcase. They find web systems more suitable in every respect than legacy systems for managing their activities because of its flexibility and universality. As a result of this, all information storage and access activities are migrating to web systems.
Recently there have been significant improvements in various aspects of mobile discipline. Powerful mobile devices are becoming more common and location tracking techniques have been improved to find the location of a mobile user with precision. The widespread use of internet, electronic shopping, mobile and wireless communication systems, etc., motivated researchers and developers to migrate all types of information and also services to the web. We, therefore, envision an all powerful web system where service provisioning is also included as one of its capabilities. The migration of web services to internet provided an excellent way to achieve application-to-application interaction which made it possible for companies to manage their business activities efficiently, economically, and with a high degree of automation. At the same time it created a continuously available pervasive market where they can enjoy their shopping, can prepare their travel planning, complete their day to day activities, and any other special activity with utmost flexibility. We call this pervasive market "Web Bazaar" which can be view as a virtual environment around us where we can find everything (items and services) close to our finger tips.

WIRELESS WEB SERVICES (WWS) SECURITY

Effective wireless application security depends on the ability to authenticate users and grant access accordingly. Existing authentication and authorization mechanisms fundamentally depend on information known to a user (password or keys), possession of an authentication device (security token or crypto card) or information derived from unique personal characteristics (biometrics). None of this is totally foolproof. Location information (latitude, longitude, height, situation.) of a mobile device or user adds a fourth and new dimension to wireless application security. It gives extra assurance to users of the wireless applications who want to perform sensitive operations such as financial transactions, access valuable information, or remotely control critical systems. It can supplement or complement existing security mechanisms. The Location Signature can still be used as a security mechanism when other systems have been compromised as it is and will always be unique for a user at any point of time. For highly sensitive wireless applications, a real time Location Signature can be generated so that authorities can trace any malicious activity back to the location of the intruder. Without the incorporation of Location Signature, it will be difficult to trace the origin of malicious activity.