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On Designing Efficient High-Speed Wireless Lans

Thesis Info

Access Option

External Link

Author

Nishat, Muhammad Kamran.

Program

PhD

Institute

Lahore University of Management Sciences

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Computer Science

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/9479/1/Kamran_Thesis_Final.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727798832

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In the last decade, wireless LANs (WLANs) based on the IEEE 802.11 standards have become ubiquitous in our daily lives. During this time we have seen more than 10-fold increase in usage and the number of wireless devices. To satisfy ever increasing demands, physical layer (PHY) data rates in WLANs have scaled from a few Mbits/sec in 802.11g to hundreds of Mbits/sec in IEEE 802.11n to over Gbits/sec in the IEEE 802.11ac standard. In addition, due to the emergence of popular online services, such as YouTube and Netflix, there has been persistent traffic growth due to real-time applications (e.g., video streaming). These trends bring about new performance challenges that are likely to become problematic for high-speed WLANs: These challenges include (a) achieving high user-level throughputs at high PHY data rates and (b) meeting the quality of service requirements of diverse applications (e.g., video streaming, web surfing, and bulk transfers) when they co-exist in a WiFi network. Due to the shared nature of the wireless medium, a carrier sensing based random access protocol is used in all 802.11-based standards. To arbitrate access to the channel, wireless access protocols introduce overheads like backoffs, preambles, and acknowledgements that lower performance efficiency at high data rates thereby resulting in low throughput. To address this inefficiency, recentWiFi standards (e.g., 802.11n/ac) allow (a) frame aggregation, whereby multiple frames are transmitted as a single aggregate frame on every channel access, and (b) block acknowledgements, whereby a single frame is to used for acknowledging the receipt of several frames. These features amortize the contention overhead over multiple frames and thus improve efficiency. At high data rates, frame aggregation introduces two challenges. First, sending large aggregate frames in a single transmission increases the opportunity cost of losing a frame, which leads to greater degradation in performance. In WiFi networks, frame losses can occur due to a weak signal, collisions, or hidden nodes. The MAC layer should respond differently to different types of losses. To achieve high performance, it is essential to infer the cause of frame loss accurately. We propose, implement and evaluate BLMon, a framework for loss differentiation that uses loss patterns within aggregate frames and their retries to achieve loss differentiation accurately and with low overhead. The second challenge arises in the presence of a mix of traffic, ranging from delay sensitive real-time applications to bulk file transfers that require high throughput. We show that using QoS mechanisms in high-speed WLANs presents a tradeoff between maximizing the performance of real-time applications and achieving high throughput. We design SlickFi; a service differentiation scheme that addresses this tradeoff and simultaneously maximizes the performance of real-time applications and network throughput. SlickFi achieves this by (a) isolating different types of traffic in non-overlapping parts of the spectrum by mapping them to different radios; and (b) adapting channel width on a per-frame basis to make efficient use of the wireless channel. The proposed solutions are readily deployable on commodity devices using only software level changes. We demonstrate the validity of our solutions by performance evaluation over a real testbed in diverse scenarios.
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اہم تدوینی اصطلاحات

موضوع2:تدوینی اصطلاحات
متن:
• تدوین کے لیے وہ تحریر جسے کوئی ترتیب دینا چاہے۔
• متن اس عبارت کو کہتے ہیں جسے آسانی سے پڑھا جا سکے اور قرات کے دوران اس کی تفہیم ہو سکے۔ متن سے ہم تاریخ یا ماضی سے تعلق رکھنے والی وہ عبارت
• مراد لیتے ہیں جس کی ترتیب مقصود ہو۔جسے دریافت کیا گیا ہو اور جو تحقیقی اہمیت کی حامل ہو۔
تدوین :
• کسی تصنیف کے مختلف نسخوں کا مقابلہ کرکے درست متن تیار کرنا
• کسی مصنف کی منتشر تخلیقات یا کسی تخلیق کے منتشر اجزائ￿ کو صحیح ترتیب سے جمع کرنا
مدون:
تدوین کا کام کرنے والا
مرتب:
کتابوں کی ترتیب دینے والا
دیوان:
وہ مجموعہ کلام جس میں شعراء کی نظمیں اور غزلیں جمع کی جاتی ہیں۔
مخطوطہ:
کسی مصنف کے ہاتھ سے لکھی ہوئی تحریر کو کہتے ہیں۔
منسوخ/قلم زد:
وہ تخلیقات یا تخلیق کا حصہ جسے مصنف نے خارج کردیا ہو۔
موازنہ:
ایک متن کے مختلف نسخوں کے اندراجات کا تقابلی مطالعہ کرکے مناسب ترین کا تعین
اختلاف نسخ:
تدوین کرتے وقت مختلف نسخوں میں جو اختلافات ملتے ہیں انھیں اختلاف نسخ کہا جاتا ہے، ان کو یک جا کردیا جاتا ہے تاکہ قاری کے سامنے دونوں صورتیں آجائیں۔
نسخہ:
کسی قلمی یا مطبوعہ کتاب کی ایک جلد کو نسخہ کہتے ہیں۔

اساسی نسخہ/بنیادی نسخہ:
کسی پرانی قلمی کتاب یا مخطوطے کے جب کئی نسخے موجود ہوں تو ان میں سے وہ نسخہ جسے بنیاد مان کر تدوین متن کی جائے اساسی نسخہ کہلاتا ہے۔
خطی نسخہ/قلمی نسخہ/دستخطی نسخہ:
مصنف کے ہاتھ کا لکھا یا ٹائپ کیا ہوا نسخہ دستخطی نسخہ کہلاتا ہے۔
آمیختہ نسخہ:
وہ نسخہ جس کا متن پہلے کے دو نسخوں سے ملا کر تیار کیا گیا ہو۔

قرآنی اصولوں کی روشنی میں معاشرتی استحکام

Islam is the religion of nature. It not only approves the social interaction among the masses, but also helps in its development towards positive ends. Islam has given natural and universal principles which help its followers to develop a harmonious society, discouraging all the attempts to divide the society into different sections. Islamic society is based upon the following fundamental principles i. E equality, harmony of thoughts, justice, amar-bilmaaruf-wa-nahi-anilmunkar (ask for good and forbid from evil), unity, sense of responsibility, virtue and evil, abolition of sectarianism & fulfillment of promises, reflecting the universality of the religion, Islam. Pakistan today, is facing various social problems like terrorism, corruption, poverty, unemployment, broken families, sectarianism, onslaught of western culture and demand of unrestricted liberty by womenfolk. The moral degradation of the society is due to the fact that the true Islamic spirit and moral teachings and trainings of Islam have not been applied with true mind and honest intentions. The moral values are ignored by the media which is the cause of great concern.

Consensual and Conflictual Political Culture in Pakistan: A Comparative Analysis of Jamaati Islami & Jamiat Ulema-I-Islam Socialization Process

This study reflects on the consensual and conflictual political culture in Pakistan and specifically in two religio-political parties i.e. Jamaat-i-Islami and Jamiat Ulema-i-Islam. It validates the argument that consensus and conflicts within political parties are because of the socialization process of their workers. It fundamentally tries to investigate the questions of “how a culture of consensus or conflict is developed through the process of socialization”. How JI and JUI socialize their workers? And “how far socialized workers in JI and JUI accommodate people of other political parties and ideologies”? The scarce literature on Jamaat-i-Islami and Jamiat Ulema-i-Islam failed to explain the political behavior of the workers of these two parties. In the political socialization scholarship, socialization is a continuous process and different agents and factors have significant roles during the whole process, which shape specific preferences of the “socialized” workers. For JI and JUI, socializing and politically educating the future citizens of the polity is the primary duty of the family. Political and social conceptions along with religious ideas and values found among members of JI and JUI are thus transmitted through, especially, parents’ in the family, more than schools, peer groups and mass media. Family transmits the parents political values and disposition to the coming generation, thus provides a continuous ideological commitment and man power to the parties. It also validates the argument that certain aspects of children’s lives, such as civic participation, shaping voting behavior and party identification etc. are in the domain of families and parents in JI and JUI affiliated families. Educational institutions established by the workers of these parties also socialize and indoctrinate the ideology of JI and JUI in the children. In terms of communicating the curricula contents and messages to the students, the role of teacher is much important. His personal values, likes and dislikes and political affiliation greatly affect the classroom discussion, learning and the intellectual growth of the youth. Student organizations (IJT and JTI) in the education institutions across Pakistan are providing a significant environment to the students and prepare them for their active political roles in the society. They work as nurseries for JI and JUI by providing them man power (socialized workers) and future leadership. Both the organizations are having regular systematic training and socialization procedures, which are missing in other contemporary student’s organizations in Pakistan. However, both JI and JUI are not much successful in utilizing the modern communication tools as compared to other political parties. The excessive commercial nature of the traditional media caught up both the parties to get maximum advantage of it in terms of propagation of their ideology and political program. Though JI is trying to fill this gap with the maximum use of social media, JUI affiliates and leadership is neither that familiar with the modern social media and communication tools nor having much involvement in the social media. D. I. Khan and Dir districts were selected for this study primarily on the basis of the parties overwhelming presence, their extensive activities in engaging their workers, their electoral gains as compared to other political parties, and lastly, in addition to belonging of the central leadership of both the parties and their electoral constituencies in these regions.