Browsing by Author "Safak, Aysel"

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Alternative Enhancement of Associativity Based Routing (Aeabr) for Mobile Networks
(Springer, 2010) Preveze, Barbaros; Safak, Aysel; 17573; 06.03. Elektrik-Elektronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This study proposes an alternative enhancement for the Enhanced Associativity Based Routing (EABR) method which is a derivation of ABR (Associativity Based Routing) by relative speed and relative distance estimation using the received power strength (RPS) of the nodes. In this study, it is shown that EABR outperforms some other well known protocols. The performance of EABR is improved in terms of number of route reconstructions (RRC) and connected status percentage (CSP). Message overhead and bandwidth utilization is also investigated.
Citation - WoS: 1
Citation - Scopus: 3
Comparative Analysis of Novel Long Life Routing Methods in Mobile Networks
(Ieee, 2010) Safak, Aysel; Preveze, Barbaros; 17573; 06.03. Elektrik-Elektronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
In this study we propose two novel ABR extended Long Life Routing Methods called Alternative enhancement for Enhanced Associativity Based Routing (AEABR) and Associativity Tick Averaged ABR (ATAABR) methods which are also modifications of Associativity Based Routing (ABR). Comparison of these associativity based long Life routing algorithms in Mobile Networks are done for route speeds, life times and outage times Since ABR at most focuses on power strength, it will be preferable in most systems to establish long life routes from source to destination considering the power constraints. It is shown in this paper that, the novel algorithms that we propose provide better life time, link speeds and outage time results than EABR (Enhanced Associativity Based Routing) method and other relay selection algorithms taken into consideration in this work. It's illustrated that the performance of EABR method, is really better than other relay selection algorithms for number of Route reconstructions (RRC) or relay changes and Connected Status Percentage (CSP). On the other hand it has also been illustrated that AEABR and ATAABR improve the connection stability of EABR by keeping the connection outage time at lower levels where ATAABR require less modification on algorithm and needs less computation time. AEABR improves either connection outage times or number of RRC. During this analysis message overhead and bandwidth wastage of each algorithm is also investigated. The proposed algorithms can be used in designing a unicast mobile network having power constraints to provide longer path life and lower number of route reconstructions.
Citation - WoS: 2
Citation - Scopus: 5
Throughput Maximisation of Different Signal Shapes Working on 802.16e Mobile Multihop Network Using Novel Cognitive Methods
(Springer-verlag Berlin, 2010) Preveze, Barbaros; Safak, Aysel; 06.03. Elektrik-Elektronik Mühendisliği; 06. Mühendislik Fakültesi; 01. Çankaya Üniversitesi
This study proposes cognitive methods for managing the multimedia packet traffic of 802.16e system providing the dynamic spectrum sharing by TDM & OFDMA under heavy traffic conditions. The cognitive techniques are used in order to maximize the throughput of a system having different signal shapes such as video, voice or data packets. All real time voice and video packets transmissions have been provided with full success where the loss rate of data packets has been minimized using the cognitive methods. By these methods buffers are managed successfully for the given parameters, optimum buffer sizes have been formulized and it's shown that we brought the throughput up to its calculated theoretical limits for multi-hop mobile wimax (802.16e).