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We discuss the requirement of basic quality of service (QoS) in optical burst switched WDM networks considering their delay and loss probability. Low delay and reducing burst overlap in the electronic domain of an ingress node reduces burst loss, and hence improves (QoS). A simplified mathematical model for delay versus traffic loads considering both low and heavy traffic conditions is developed. In optical domain we have studied the delay characteristics for the offset-time-based scheme with fiber delay lines (FDLs). The minimum delay zone is shown considering the variation of channel capacity C, burst size B, offset time depending on degree of isolation, burst overlapping parameters, and token round trip time R in a metropolitan area network (MAN). Finally, numerical calculation and simulations in priority queue management for different class of service (CoS) show the results are very close, thus validating our approximate delay model. The results show the reduction for higher priority packet latency and the conditions so that low priority packets are not severely dropped. Index Terms-Optical burst transport (OBT), quality of service (QoS), delay characteristics and priority, burst overlap reduction, class isolation, metropolitan area network (MAN).

A compact Fork-shaped Microstrip patch antenna with improved bandwidth is presented in this paper. The proposed antenna is design and analysis with dielectric substrate of RT/Duroid 2.2 and substrate thickness 3.17 mm. Antenna resonates at multi band of 7.46 GHz and 4.46 GHz .The proposed antenna is optimized with ANN model .The comparison between measured, simulated and ANN results for slotted microstrip patch antenna has been discussed. The proposed antenna has been fabricated and tested in laboratory .The measured and simulated results are exhibits good agreement. The proposed antenna achieved 40.34% of bandwidth at centre frequency of 7.46 GHz with VSWR ≤ 2 and gain is 4.09dBi.