Methods and apparatus for providing enhanced optical networking service and performance which are particularly advantageous in terms of low cost and use of existing infrastructure, access control techniques, and components. In the exemplary embodiment, current widespread deployment and associated low cost of Ethernet-based systems are leveraged through use of an Ethernet CSMA/CD MAC in the optical domain on a passive optical network (PON) system. Additionally, local networking services are optionally provided to the network units on the PON since each local receiver can receive signals from all other users. An improved symmetric coupler arrangement provides the foregoing functionality at low cost. The improved system architecture also allows for fiber failure protection which is readily implemented at low cost and with minimal modification.

Broadband optical network apparatus and method

As of today Ethernet is used in the in-vehicle network mainly for two use cases: connectivity between the head unit and the rear seat entertainment (RSE) as well as faster onboard diagnostics (OBD). With the increasing bandwidth demand in driver assistance and the wish to easier interconnect the driver assistance and infotainment domains additional usage of Ethernet in the vehicle is being examined. The legacy Ethernet does only provide very limited Quality-of-Service (QoS) mechanisms so that demanding real-time in-vehicle applications cannot meet their constraints. The Audio/Video Bridging (AVB) group introduced several IEEE standards to allow audio and video applications with high QoS demands in a switched Ethernet network. Although these mechanisms were not designed for automotive use cases, they are good extensions to switched Ethernet when QoS demands exist. Therefore, an evaluation of AVB for the usage in in-vehicle networks is needed. In this work, we focus on a base mechanism of the IEEE 802.1 AVB standard, the IEEE 802.1AS time synchronization protocol and its usage in the in-vehicle network. The evaluation is performed by simulation with the network simulation tool OMNeT++ and we modifed the INET-framework with the IEEE 802.1AS capability for our purpose.

IEEE 802.1AS time synchronization in a switched Ethernet based in-car network

We review recent progress on all-optical virtual-private-network (VPN) schemes in passive optical networks (PONs). PON is a promising candidate in future access areas to provide broadband services with low cost. With all-optical virtual private network (VPN) function, PON can support efficient internetworking among end users with dedicated optical channels, thus enabling guaranteed bandwidth and enhanced security at the physical layer. Here, we discuss and compare existing schemes of all-optical VPNs in time-division-multiplexed (TDM) PONs, and also recently proposed schemes for deployment in wavelength-division-multiplexed (WDM) PONs and two-stage TDM/WDM PONs.

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All-optical virtual private network in passive optical networks

This paper proposes and experimentally demonstrates an automatic-protection-switching (APS) mechanism against distribution fiber breaks in passive optical networks (PONs). The protection of optical-network units (ONUs) that are located at the customer premises is carried out by monitoring the distribution fiber using the traffic that is transported among the customers in the PON. This configuration emulates a local area network (LAN) over the existing PON while facilitating the switching of signal transmissions to a predetermined protection path in an event of a distribution fiber break. As failure detection and APS are performed independently by each ONU in a distributed manner, the processing complexities and delays are reduced at the central office (CO). The restoration of the traffic transported between the CO and an ONU in the event of the distribution fiber break is performed by interconnecting adjacent ONUs and carrying out signal transmissions via an independent but interconnected ONU. Such a protection mechanism enables multiple adjacent ONUs to be simultaneously protected by a single ONU utilizing its maximum available bandwidth. This paper experimentally verifies the feasibility of the proposed protection mechanism in conjunction with two different LAN-emulation schemes with a 1.25-Gb/s upstream baseband transmission to the CO and a 155-Mb/s LAN data transmission on a radio-frequency carrier. The experimental results obtained from both schemes are compared, and the power budgets are calculated to analyze the scalability of each scheme.

Protection switching and local area network emulation in passive optical networks

Aspects of a method and system for utilizing a single connection for efficient delivery of power and multimedia information are provided. In this regard, power supplied and/or received over a network link may be controlled based on multimedia content communicated over the network link. The multimedia content may be converted to and/or from Ethernet frames for communication over the network link utilizing audio video bridging. The multimedia content may be raw video or may be formatted according to, for example, HDMI or DisplayPort specifications. The power supplied may be controlled by selecting one of a plurality of power classes. The selection of power class may be based on resolution of the multimedia content, whether the multimedia comprises audio and/or video, and/or based on latency targets.

Method And System For Utilizing A Single Connection For Efficient Delivery Of Power And Multimedia Information

We propose a method to implement a 155-Mb/s optical star network using existing passive optical network (PON) cable plant and demonstrate its feasibility experimentally. The light-emitting diode- (LED) based optical star network, wavelength-compatible with the asynchronous transfer mode (ATM) PON system, showed a power penalty of 1.1 dB compared to back-to-back connection. The overlay network had little effect on ATM PON signals.

An ATM PON system overlaid with a 155-Mb/s optical star network for customer networking and fiber to the premises

An N/spl times/N star coupler and N optical network units with a circulator and two fiber Bragg gratings were employed to form a fully transparent, 155 Mb/s optical star network over the existing asynchronous transfer mode (ATM) passive optical network (PON) system

A new ATM PON system suitable for local access and local private networking services

With the growth of digital media devices, researchers are developing techniques for transmission of real-time trafficover the network. Above all, network techniques that utilize Ethernet are in the limelight because of the advantages of Ethernet. A standardized network technique for isochronous traffic over Ethernet is in progress in IEEE 802.1 Audio/Video Bridge Task Group (AVB TG). This paper proposes a network technique for real-time traffic over an Ethernet model, that is, a AVB model with a synchronization method between devices. This paper proposes time synchronization and resource reservation for transmission of real-time traffic in synchronized devices. In this paper, we implement a AVB model through OPNET, and analyze the efficiency of the proposed methods.

Time Synchronization and Resource Reservation for Time-Sensitive Applications in Bridged Local Area Networks

Time and frequency alignment is critical for ensuring QoS for application such as voice, real-time video, wireless hand-off, and data over a converged access medium. To satisfy the accuracy of time synchronization, both adjusting Communication path asymmetry and ratio of frequency between the time-aware systems are important. Network Time Protocol (NTP) is not satisfies time-sensitive applications. IEEE 1588 Precision Time Protocol (PTP) and IEEE 802.1AS don’ t calculate the communication path asymmetry. We propose the Single-TimeSync frame for reducing the number of control frames, adjusting propagation delay asymmetry and ratio of frequency originated with slave time-aware station clock. We simulate with base model in OPNET.

Timing and Synchronization with Propagation Delay Symmetry and Originated Slave Clock Frequency for Ubiquitous Computing

Time and frequency alignment is critical for ensuring QoS for applications such as voice, real-time video, wireless hand-off, and data over a converged access medium. To satisfy the accuracy of time synchronization, propagation delay measurement is required between time-sensitive devices. There is existing network technology for time synchronization, such as network time protocol (NTP), IEEE 1588 precision time protocol (PTP), and IEEE 802.1AS. NTP, however, is not suitable for synchronization in time-sensitive applications. IEEE 1588 PTP and IEEE 802.1AS have problems where there are too many messages in LAN. We propose a single frame format and a method of propagation delay measurement using a single frame in bridged LANs. The experiment results show that the proposed method reduces time variation from NTP and control messages about 47% from IEEE 802.1AS.

Jong-Hoon Eom

Papers

An ATM PON system overlaid with a 155-Mb/s optical star network for customer networking and fiber to the premises

A new ATM PON system suitable for local access and local private networking services

Time Synchronization and Resource Reservation for Time-Sensitive Applications in Bridged Local Area Networks

Timing and Synchronization with Propagation Delay Symmetry and Originated Slave Clock Frequency for Ubiquitous Computing

Propagation Delay Measurement Using A Single-TimeSync Frame in Bridged Local Area Networks