Samir K. Sadhukhan

Learn More
e-business organizations are heavily dependent on distributed 24X7 robust information computing systems, for their daily operations. To secure distributed online transactions, they spend millions of dollars on firewalls, anti-virus, intrusion detection systems, digital signature and encryption. Nonetheless, a new virus or a clever hacker can easily(More)
In conventional UMTS cellular networks, during deployment usually a set of NodeBs is assigned to one Radio Network Controller (RNC), and a set of RNCs to one Serving GPRS Support Node (SGSN) for data services, as well as to one Mobile Switching Centre (MSC) for voice services. Operators thus far have considered single-homing of RNCs to MSCs/SGSNs (i.e.,(More)
In real-life scenario where users mostly know their destinations a priori, their movement is not purely random (as assumed in random walk model); rather it is somewhat direction-based and depends on the present location and the final destination. For instance, an office goer often returns home in the evening (i.e., mobility is diurnal). While no existing(More)
Search in cyclic AND/OR graphs was traditionally known to be an unsolved problem. In the recent past several important studies have been reported in this domain. In this paper, we have taken a fresh look at the problem. First, a new and comprehensive theoretical framework for cyclic AND/OR graphs has been presented, which was found missing in the recent(More)
WDM networks are increasingly gaining popularity as the backbone networks all over the world. In WDM network planning, electronic equipments like ADMs contribute heavily towards the capital expenditure of the network (Each ADM costs $50,000-$200,000).In WDM rings, determining minimum number of ADMs is NP-Hard. All the previous works have focused on(More)
2.5 cellular network topology involves grouping of NodeBs into Radio Network Controllers (RNCs), RNCs into serving GPRS support nodes (SGSNs), and RNCs into mobile switching centres (MSCs), so as to minimize the total cost of operation (TCO) including equipment cost, cable cost, installation cost, cost of call setup and handoff cost. The problem has been(More)
Next generation wireless technologies offer various services from voice call to full motion pictures and even to high speed internet access. Consequently, the service providers (SP) armed with different wireless technologies (like 2.5G/3G/LTE) would require an adequate and significant amount of spectrum bandwidth for satisfying the need of their customers.(More)
We consider a scenario where a single service provider (SP) owns multiple access networks (ANs) of different (not necessarily competing) technologies. It employs an entity, called spectrum controller (SC), which manages the common pool of spectrum and is responsible for distributing the spectrum to individual ANs in a fair manner. Since the available(More)
3G Cellular networks typically consist of a group of NodeBs connected to a Radio Network Controller (RNC), and a group of RNCs to a Serving GPRS Support Node (SGSNs) as well as to a Mobile Switching Centre (MSCs). Post deployment planning of such network is to re-plan the connectivity among the above mentioned network elements with an objective to minimize(More)