الاستخبارات في العهد المكي: دراسة تحليلية

Security is most important need of every state and community. Surveillance and keeping eye on the enemy are the core responsibilities of every state. All the absolute qualities of a leader can be found in The Holy Prophet (P.B.U.H). Therefore, the first nucleus of security education was in Makkah and expanded with the expansion of the Da’wah till the declaration of Madina as a Islamic state. There are various studies on the subject of surveillance, but they did not cover all aspects of Sīrah in Makkī era regarding the various steps and methods of surveillance. This article investigates how the Holy Prophet (P.B.U.H) maintained the security measures during Makkī era to ensure the security of all his companions and followers. In the First section of this article definition and history of intelligence was discussed, followed by the various techniques of surveillance used in different occasions by the Prophet (P.B.U.H). The last section of the article focused on the techniques used in Makkī era. The article further elaborates the practical steps taken by Prophet (P.B.U.H) to secure his companions and their families from the opponents to the extent possible, like migration to Habash and finally to Madina which concluded in establishment of a free state for Muslims.

Interference and Capacity Analysis in Wireless Mesh Network

CSMA based MAC protocols are known to incur throughput imbalance when employed in multi hop wireless networks and existing literature lacks efficient MAC protocol for wireless mesh networks. Accurate modeling of interference and its affect on throughput of flows in the WMN is critical in designing future wireless networking protocols. This thesis performs a thorough analysis of interference and capacity in wireless multi hop network based on CSMA/CA MAC behavior. It is hypothesized that accurate modeling of interference at MAC level can maximize overall network capacity. In first part of thesis, twenty five unique possible two flow topologies have been classified into six categories based on MAC layer behavior and per flow throughput and closed form expressions for occurrence probabilities of the identified categories have been derived with particular observation that carrier sensing range based categories have high occurrence probability and cannot be ignored. MAC behavior of each category is discussed. In the second iii iv part, accurate computation of conditional packet loss probability and busy time is done based on geometrical configuration of the interfering links and also predicted per-flow throughput while addressing CSMA’s coordination problem. Unlike previous work, our analytical throughput model can clearly differentiate between links interfering from transmission range and carrier sensing range. Analytical and empirical results demonstrate improved accuracy, indicate throughput imbalances and provide better understanding of CSMA based protocol behavior in multi-hop wireless networks that can be used to design fair, scalable, and efficient MAC layer protocols.