T. Ozugur

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This paper addresses load balancing algorithms for the wireless links to solve the fairness problem, where stations are not able to gain access equally to the shared wireless medium according to the current medium access control protocols. The fairness problem occurs mostly because of the existence of hidden stations and the presumption of a non-fully(More)
In this paper, we first propose four-layer optimization for UMTS coverage area: (i) cell-oriented intra-SGSN layer, which is optimized RA areas covering the intra-SGSN signaling cost, paging cost and RA load balancing, (ii) RA-oriented intra-MSC layer, which is optimized location areas covering the intra-MSC signaling cost and LA load balancing,(iii)(More)
In this paper, we evaluate the performance of infrared communication methods using repetition-rate coding over L-PPM wireless links to provide reliable infrared transmission throughout the indoor environments. All receivers adapt the communication data rate by monitoring the channel, and they instruct transmitters to use highest rate if it is possible.(More)
Instant Messaging (IM) emerges as a powerful communication tool, not just for teenagers but also in the enterprise. After enjoying the early benefits of the " raw " presence IM provides, we are now beginning to leverage the power of presence in combination with telephony and collaboration tools. Most " information workers " today routinely use a computer(More)
Provisioning dynamic traffic is a major challenge in wavelength-routed networks. While the routes of connections are mainly determined by using global state information, different connections that share the same link may still compete for the same resources. These conflicts can cause significant blocking, a problem that becomes more serious as traffic(More)
In this paper, we propose a congestion control algorithm, referred to as Upstream Resource Management Propagation algorithm for label-switched Optical Burst Switching to provide congestion control in GMPLS control-plane infrastructure. The algorithm controls the transmission control between congested node and the ingress Edge Routers. The congested node(More)
We design a protocol for paging (tracking agent based paging or TAP) IEEE 802.11 wireless LAN hosts. Mobile nodes in IEEE 802.11 BSS constitute a layer-2 paging area. The tracking agent (TA) is in charge of the paging state, and TA continuously updates the paging state after each layer-2 handoff. Paging on the wireless link is done by extended beacons, and(More)
In this paper, the use of packet-level acknowledgements in the infrared medium access control layer is discussed. The infrared link access control protocols use Go-Back-N automatic repeat request (ARQ) scheme currently, and any ARQ scheme is optional in the medium access control layer. The advantages and disadvantages of using Stop-and-Wait ARQ scheme in(More)
In this paper, we use prediction algorithms to estimate the behavior of VBR video traac based on statistical short-term earthquake prediction methods. The probabilistic estimation of future inter-arrival times of peak values of MPEG-VBR video stream is considered in terms of Bayes theorem, and the Bayesian analysis of peak rate sample is evaluated on the(More)