Nokia Corporation

Nokia Solutions and Networks Oy

Schofield Technologies, Inc.

Nokia Technologies Oy

Antti Olavi Pietiläinen

Simo Kaarlo Tammela

Yinghua Ye

Mikko Juhani Söderlund

A method, apparatus, and computer program product for operating a network node of a computer network is provided. According to an embodiment, in a first network node of a time synchronization network interconnecting the first network node with at least one second network node of the time synchronization network is detected synchronization of the first network node and the at least one second network node; and in the first network node is determined, at least one criterion for processing at least one packet of a time synchronization protocol wherein said at least one criterion is capable of causing discarding of the at least one packet of the time synchronization protocol when the at least one criterion is fulfilled.

Enhancing synchronization in computer network

A solution for detecting and recovering from a failure in a protected single-fiber passive optical network. A detector is used to detect the degradation in power level of optical signals. Furthermore, the invention discloses a variable symmetric split ratio approach to improve the number of splits (e.g. the number of ONUs). A single-fiber passive optical network is disclosed that uses a plurality of passive nodes connected in the optical fiber between the interfaces, wherein in the passive nodes 2-by-2 splitters/combiners are used to couple optical power from and into the optical fiber at a predetermined split ratio.

Single-fiber protection in telecommunications networks

This invention relates to detecting a pilot tone in an optical fiber. In the method described in the invention, computational complexity is reduced significantly by almost completely removing the need to carry out multipli-cations. To calculate certain spectral components of DFT (Discrete Fourier Transform) only a few multiplications are required. The idea is that for de-tecting one pilot tone, it is adequate to calculate one spectral component of DFT if a specific ratio can be chosen between the pilot tone frequency and the sample rate of the receiver.

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Espoo, Finland

Antti Olavi Pietiläinen