Efficient Routing of Star–Ring Hybrid Topology with Optical Add and Drop Multiplexer in DWDM System

This paper investigates the performance of star–ring hybrid topology networks with optical add and drop multiplexer (OADM) in dense wavelength division multiplexing (DWDM) system with 0.8 nm channel spacing at different bit rates (5, 10 and 15 Gbps) in terms of bit error rate (BER), quality factor and optical signal-to-noise ratio (OSNR). OADM has the capability to add and drop the new channels and provides the wavelength routing between star and ring topologies. It is observed that the hybrid topology supports 128 users on upper and lower ends with 150 km distance between the nodes of ring network without dispersion compensating fiber.

OXADM dalam Sistem Keselamatan Rangkaian Cincin Metropolitan

Pemultipleks Tambah Gugur Silang Optik (OXADM) merupakan satu peranti optik hibrid baru yang dihasilkan melalui gabungan dua peranti asal, iaitu Pemultipleks Tambah Gugur Optik (OADM) dan Sambung Silang Optik (OXC). Ianya telah dibangunkan berdasarkan kajian terhadap kelemahan peranti sedia ada dengan beberapa ciri baru dan menarik telah dimasukkan. OXADM diperkenalkan untuk meningkatkan tahap keselamatan dalam rangkaian cincin. Dengan adanya ciri ‘Pengumpulan’ membolehkan perlindungan multipleks diaktifkan di mana kesemua isyarat yang melalui nod optik akan dikumpulkan di atas satu talian perlindungan/persediaan sekiranya berlaku kerosakan pada talian bekerja dalam rangkaian optik cincin. Antara skema perlindungan lain yang diperkenalkan oleh OXADM ini adalah perlindungan linear dan perlindungan cincin. OXADM membenarkan isyarat membuat pusingan secara ‘U’ secara dalaman untuk mengkuarantinkan kawasan kerosakan daripada kawasan yang selamat. Kedua–dua ciri inilah yang membezakan OXADM dengan peranti–peranti sebelumnya. Dengan adanya peranti OXADM ini membolehkan sebarang kerosakan yang berlaku dalam rangkaian optik dapat dipulihkan segera dengan mengaktifkan skema perlindungan yang sesuai berdasarkan jenis dan lokasi kerosakan yang berlaku. OXADM ini merupakan peranti pertama yang mengintegrasikan ketiga–tiga jenis mekanisme keselamatan rangkaian di dalam satu peranti. Kata kunci: OXADM; skema keselamatan; rangkaian cincin; simulasi, perkakasan The Optical Cross Add & Drop Multiplexer (OXADM) is a new hybrid optical device which has the combination of the original Optical Add And Drop Multiplexer (OADM) and Optical Cross Connect (OXC) devices. OXADM is developed based on the study on the demerits of the existing devices and new features are added to the device. OXADM is introduced to increase the survivability in ring architecture network. With its ‘Accumulation’ feature enable the multiplexing protection scheme can be activated where all the signals pass through an optical node are multiplexed onto a single path as a protection/preparation in case breakdown happens at the working line in an optical ring network. Other protection schemes provided by OXADM are the Linear Protection and Ring Protection. OXADM enable the signal to route internally as U turn to segment the breakdown area from the safe area. Both features have differentiated the OXADM with the previous existing device. With this new OXADM device, any breakdown happens in an optical network can be quickly fixed by activating the appropriate protection scheme based on the type and the location of the breakdown. OXADM device is known as the first device that integrates all three network safety mechanisms onto a single device. Key words: OXADM; protection scheme; ring network; simulation; hardware