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Network, IEEE

Issue 2 • Date March 1989

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Displaying Results 1 - 5 of 5
  • Non-coherent photonic frequency-multiplexed access networks

    Publication Year: 1989 , Page(s): 4 - 12
    Cited by:  Papers (19)  |  Patents (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (737 KB)  

    Noncoherent WDMA/FDMA (wavelength-division multiaccess/frequency-division multiaccess) networks that use tunable filters to select channels are considered. They have the same sensitivity as direct-detection networks, which is about 10 dB less than coherent networks. However, the noncoherent networks are much less complicated, which makes them interesting for multiaccess applications, where cost is more important than sensitivity. The direct-detection sensitivity is sufficient to allow as many as 1000 channels. Some recent research network experiments and progress on essential components for realizing noncoherent FDMA networks are reviewed.<> View full abstract»

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  • Frequency division multiplexed optical networks using heterodyne detection

    Publication Year: 1989 , Page(s): 13 - 20
    Cited by:  Papers (11)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (709 KB)  

    The optical heterodyne process is described. Because the best attainable system gain (transmitter power divided by receiver sensitivity) is only about 50 dB for lightwave systems, as compared with values approaching 100 dB at radio frequencies, it is extremely important in building an optical network (such as a local area network, or LAN) to minimize excess tap losses. It is shown that a star coupler provides a nearly ideal means for interconnecting a multiterminal network. Three areas in which problems unique to optical systems have been discovered are discussed. Theses are transmitters for coherent optical systems, optical frequency determination and control, and polarization control and optical receivers. Experimental progress is briefly discussed.<> View full abstract»

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  • Combining frequency-division and code-division multiplexing in a high-capacity optical network

    Publication Year: 1989 , Page(s): 21 - 30
    Cited by:  Papers (22)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (909 KB)  

    The combination of frequency division and code division multiplexing in a multiaccess network such that the beneficial aspects of each technique mitigate the shortcomings of the other is addressed. The feasibility and expected performance of the resulting hybrid network are examined. CDMA (code-division multiple access) is used to eliminate the need for laser frequency control, which is required for pure FDMA (frequency-division multiaccess) schemes. On the other hand, an FDMA-like mutual avoidance scheme exploits the limited tunability available to keep signals away from one another as much as possible, relieving the need for CDMA to protect against more than the occasional crossover of one interfering signal. This significantly limits the amount of spectral spreading required. The use of the hybrid network for high-bit-rate and low-bit-rate applications is discussed. The power budget for a local network utilizing a star coupler is outlined.<> View full abstract»

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  • Emerging optical code-division multiple access communication systems

    Publication Year: 1989 , Page(s): 31 - 39
    Cited by:  Papers (39)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (725 KB)  

    All-optical systems, which perform signal processing functions optically so that the signal conversion from optical to electrical is done only when desired, are considered. Three such schemes are discussed, namely, fiber-optic code-division multiple-access (CDMA) systems, neuromorphic CDMA systems, and ultrashort-light-pulse CDMA systems. Fiber-optic CDMA systems in which incoherent optical signal processing techniques are used to establish optical CDMA systems are first examined. In particular, a novel class of sequences for incoherent fiber-optic CDMA systems, called optical orthogonal codes, are discussed. The codes are then applied to neuromorphic optical systems, and various applications of the networks are examined. Recent experiments that demonstrate the ability to encode and decode extremely fast, femtosecond optical pulses and that suggest the possibility of ultrahigh-speed CDMA systems based on ultrashort light pulses are described.<> View full abstract»

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  • Network, transport, and switching integration for broadband communications

    Publication Year: 1989 , Page(s): 40 - 51
    Cited by:  Papers (15)  |  Patents (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (966 KB)  

    It is shown how the development of technologies causes shifts in the relative use of space-, time-, and frequency-division multiplexing. Novel and integrated versions of these for integrated optical networks are examined. Synchronous and asynchronous transfer nodes are defined and discussed. The use of fixed-length and variable-length packets is considered. Mechanisms of switching in the space, time, and frequency domains are described.<> View full abstract»

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Aims & Scope

IEEE Network covers topics which include: network protocols and architecture; protocol design and validation; communications software; network control, signaling and management; network implementation (LAN, MAN, WAN); and micro-to-host communications.

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Editor-in-Chief
Xuemin (Sherman) Shen, PhD
Engineering University of Waterloo