Browsing by Author "Ferdous, Hasan Shahid"

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A study on the challenges and importance of vehicular network in the context of Bangladesh
(© 2011 Institute of Electrical and Electronics Engineers Inc., 2011) Naz, Farah; Chowdhury, Tanzina Akter; Sabah, Sanjida Hossain; Ferdous, Hasan Shahid
The emergence of vehicular ad-hoc network (VANET) has provided the vital answer to vehicular communications. VANET can be either infrastructure based or simply lacking any. In our paper, we have dealt with an exemplary network that requires the presence of no such agent. VANET acts in a way applying any of the three methods: it either exchanges information between vehicle to vehicle, vehicles to roadside units and lastly the roadside units themselves exchange data through the communication channel. Previously, its operation was dependent on only WiMAX and WiFi to a large extent, but new breakthroughs have found VANET being thoroughly reliant on WAVE. We found that VANET has many challenges both on a global scale and for Bangladesh too. We identified the unique challenges posed by the lack of infrastructure, poverty and other issues present in a third world country. We have tried to address and provide a basic overview about all these restrictions in this paper and finally, we have also talked about a demonstration software we created to show the necessity and application of vehicular network in the reason - helping people in avoiding roads with traffic jams.
Cognitive radio wireless networks
(BRAC University, 2011-04) Joyantee, Tasnia Jahed; Iqbal, Niaz; Das, Ipshita; Ferdous, Hasan Shahid; Sabah, Sanjida Hossain
Standards groups and regulatory bodies around the world are increasingly seeking new ways of using, allowing access to, or allocating spectrum. In most parts of the world, cellular network bands are overloaded, but amateur radio and paging frequencies are not. Independent studies performed in some countries confirmed that observation, and concluded that spectrum utilization depends strongly on time and place. Moreover, fixed spectrum allocation prevents rarely used frequencies (those assigned to specific services) from being used by unlicensed users, even when their transmissions would not interfere at all with the assigned service. This was the reason for allowing unlicensed users to utilize licensed bands whenever it would not cause any interference (by avoiding them whenever legitimate user presence is sensed). This paradigm for wireless communication is known as cognitive radio.
Design challenges and scope for cognitive radio wireless networks in Bangladesh
(© 2011 Institute of Electrical and Electronics Engineers Inc., 2011) Jahed, Tasnia; Das, Ipshita; Iqbal, Niaz; Sabah, Sanjida Hossain; Ferdous, Hasan Shahid
Standards groups and regulatory bodies around the world are increasingly seeking new ways of using and allowing access to allocating spectrum. In most parts of the world, cellular network bands are overloaded, but amateur radio and paging frequencies are not. Independent studies performed in some countries confirmed that observation, and concluded that spectrum utilization depends strongly on time and place. Moreover, fixed spectrum allocation prevents rarely used frequencies (those assigned to specific services) from being used by unlicensed users, even when their transmissions would not interfere at all with the assigned service. In this research we studied the frequency usage pattern of a large telecom company to identify the possibility of establishing a cognitive radio network using their licensed band. Experimental simulation results shows that a carefully designed network will boost the throughput significantly.
Performance comparison of medium access control schemes for IEEE 802.11
(BRAC University, 2012-04) Ahmed, Lubna; Alam, Mahjabeen; Kabir, Amran; Ferdous, Hasan Shahid
IEEE 802.11 specifies a set of protocols for a wireless LAN defined by IEEE which covers the physical and data link layer. Nowadays, IEEE 802.11 based WLAN has a widespread and ubiquitous use in providing wireless connectivity to several electronic devices like cell phones, laptops, gaming devices and so on. All these devices operate on the same medium and contend with each other in order to access the medium. All devices using the IEEE 802.11 Standard adopt a basic MAC scheme called the distributed coordination function (DCF) whose key function is contention resolution. The Binary Exponential Backoff (BEB) scheme is used to access the medium and deliver packets over a wireless network. However, the performance and efficiency of IEEE 802.11 DCF scheme is a matter of question as the number of contending stations are increasing everyday. In this paper we make a detailed study of the performance comparison between DCF, CONTI, k-EC and PREMA, which are various contention resolution schemes proposed in various independent researches. The criteria for performance comparison that we will use are collision rate, throughput and average delay between successful transmissions. Also, in this paper we are going to propose an unsaturated model for the contention schemes whose implementation and performance is consistent with the saturated mode used in the above contention schemes. Furthermore, we compare the performance for each of the contention resolution schemes in the unsaturated mode.
Performance comparison of medium access control schemes for IEEE 802.11
(© 2012 Institute of Electrical and Electronics Engineers Inc., 2012) Kabir, Amran B M Zohrul; Alam, Mahjabeen A.; Ahmed, Lubna; Sabah, Sanjida Hossain; Ferdous, Hasan Shahid
The distributed coordination function (DCF) of the IEEE 802.11 standard based medium access control has drawn significant interest from the researchers in the past decade. Many proposals of its performance analysis and modifications to remove its limitations are proposed. In this paper we are considering some recent proposals to make a detailed study of the performance comparison between DCF, CONTI, k-EC, and PREMA, which are various contention resolution schemes proposed in various independent researches. The criteria for performance comparison that we use are collision rate, throughput, and average delay between successful transmissions. Also, we consider queuing delay using an exponential on-off based unsaturated model for these protocols whose implementation and performance is consistent with the saturated mode used in the above contention schemes.
Survey on the clustering schemes of mobile ad-hoc Wireless Sensor Network (WSN)
(BRAC University, 9/4/2012) Ahmed, Mushrif; Sarker, Rakesh; Ferdous, Hasan Shahid; Sabah, Sanjida Hossain
This report aims to do a complete study on the different clustering algorithms of an ad-hoc wireless sensor network and compare them. In this paper we have understood, what are the basics of the 802.11 protocol, what is a wireless ad-hoc sensor network , what is a Mobile Ad-hoc Network (MANET), and details of Clustering . We have further understood what is clustering, why it is necessary, and the different clustering schemes. Among these we have understood their clustering process, the cluster maintenance, benefits and drawbacks , and finally compared them with each other . In our thesis we work with four clustering scheme and try to find out their formation and cluster head selection process time. We have understood these various concepts by extensive study of IEEE papers and acquiring information from the internet. We hope that our report will aid anyone seeking to understand information on this topic and be a concise compilation of information for their research or study.