Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/444—Systems or boxes with surplus lengths
  • G02B6/4441—Boxes
  • G02B6/4448—Electro-optic

Definitions

• the present invention relates to an arrangement for connecting several optical fibres to an external connection point, such as an arrangement for connecting several optical fibres from dwellings in an apartment block to an external connection point, said arrangement including a unit for switching optical signals transported by the optical fibres between said dwellings and said arrangement and between the arrangement and said external connection point.
• optical fibre networks for dwelling places, where individual apartments are connected by optical fibres to a central unit, for example a router.
• the central unit is then connected in turn to a transport network for the transmission of information from the individual apartments/dwelling places to said transport network, for instance the Internet.
• US005872644A teaches an optical fibre access system for optical subscriber communication between dwelling places and a central unit, where each dwelling place is connected by optical fibres to one of a number of optical transmitting modules (Tx) and to one of a number of optical receiver modules (Rx), said modules being connected to a communications switch.
• Tx optical transmitting modules
• Rx optical receiver modules
• the centrally located arrangement may have the form of a cabinet, a so-called capsulation cabinet, consisting essentially of two parts: a passive part and an active part.
• the fibre optic passive part is comprised of a transition from optical 5 fibres carried in ducts, so-called microducts, from the dwelling places to a fixed cross- coupling and a switch unit.
• the electrically active part is comprised of the switch unit and a converter.
• the cabinet is constructed on the concept of coupling the passive optical fibre part and the active electronic part together and to an optical fibre network that is capable of providing subscribers with 100 Mbps fibres (SX) lines, in a simple fashion and within a
• the active part and the passive part are each disposed in respective, adjacent smaller spaces in the encapsulating cabinet, with separate doors and keys. This minimises the risk of unauthorised access to the cabinet and to sensitive components housed therein, and also allows the functions to be separated.
• the cabinet may primarily be intended to be mounted on walls inside a building, and may be fastened to a wall
• Figure 1 illustrates an optical fibre network connected to a subscriber.
• Figure 2 illustrates a switch unit for local switching of signals in the network shown in 25 Figure 1.
• Figure 3 is a perspective view of an encapsulating cabinet that includes a passive part and an active part in accordance with the invention and intended for use in the optical fibre network according to Figures 1 and 2.
• FIG. 4 is a detailed illustrated in different views of an encapsulating cabinet organiser. DESCRIPTION OF PREFERRED EMBODIMENTS
• Figure 1 illustrates an optical fibre network for connection to a subscriber.
• the fibre network is comprised of a local switching unit 101 that connects pairs of optical fibres 103 to individual subscriber/dwelling places 105 with a local optical fibre loop 107.
• the local optical fibre loop 107 is, in turn, connected to a central unit 109 which, in turn, may be connected to a transport network 11 1, such as the Internet, in a conventional manner.
• the inclusion of the local switching unit 101 affords a number of advantages over a conventional optical fibre network for subscriber connection (Fibre To The Home/FTTH).
• the local switching unit will preferably be housed in a robust casing that can be placed in a basement or in a loft or attic of a building without risk of damage to the electronic components.
• switching is effected on a local level, meaning that the traffic load to the central unit will be reduced since all traffic transmitted between subscribers connected to the same switching unit need never be sent to the central unit 109.
• the switching unit may include a CPX 201 for cross-connection of signals to/from different subscribers connected to the switching unit.
• CPX 201 is connected to a PIN diode array 203 and to a VCSEL laser array 205.
• the PIN diode array receives signals arriving at the switching unit and the VSCEL laser array 205 transmits signals from the switching unit.
• the PIN diode array and the VSCEL laser array are each connected to a respective optical fibre ribbon. These fibre ribbons are cross-connected in the CPX, so as to form receiver/transmitter pairs. Each individual pair is then connected to a given subscriber.
• the PIN diode array 203 is connected to an amplifier 207, which is connected in turn to a conventional packet-handling unit 209.
• the packet-handling unit 209 is connected to a block 211 that includes a distribution selector, appropriate filters, and preferably also support for handling a VLAN (Virtual Local Area Network).
• the block 21 1 is connected to a packet switch 213.
• the packet switch 213 is connected to a buffer 215 in which a packet outputted from the packet switch is stored while waiting to be transmitted from the switching unit.
• the buffer will preferably have support for handling different priorities relating to the transmitted packets.
• the buffer 215 is then connected to a conventional packet manager 217 and an amplifier 219, which, in turn, are connected to the VCSEL laser 205.
• the switching unit will include filters for preventing information sent to/from an individual subscriber from being received by another subscriber connected to the same switching unit. Filtering of information is also effected to prevent one subscriber disturbing another subscriber connected to the same switching unit.
• different subscribers can be given different connection qualities, providing so-called virtual networks (Virtual Local Area Network/VLAN).
• switching on local levels can be carried out, i.e. traffic to/from subscribers connected to one and the same switching unit can be cross-connected in the switching unit on local levels.
• FIG 3 shows an example of a so-called encapsulating cabinet IA and IB which includes a passive part and an active part and which is constructed in accordance with the invention for enclosing the switching unit show ⁇ in Figure 2, among other things.
• the cabinet IA and IB is shown with open doors/covers 2 A and 2B, and also in a partially separated view.
• the cabinet is preferably made of 1.5 mm lacquered steel plate and aluzinc plate, and may be painted in structured coral white.
• the passive components such as eight cassettes 3 for handling 96 optical fibres/48 fibre ribbons and an organiser, this number of optical fibres and fibre ribbons being a maximum at present.
• Incoming multiduct cables and/or microducts carrying optical fibres from different apartments in an apartment block shall be capable of being installed in the cabinet in accordance with a particular installation plan.
• Holes 4 are provided in the back piece of the cabinet for the insertion of ducts/pipes carrying optical fibres from said apartments.
• the ends of the various ducts/pipes are then placed in the organiser 5 (see Figure 4) such as to place the optical fibres in the ducts/pipes in order and to enable said fibres to be handled more easily at the transition of the fibres from the ducts/pipes to the cassettes.
• the organiser 5 may comprise a combined ladder-like holder for individual pipes or pipe-ends, where the pipe-ends can be placed parallel one above the other in recesses 17 on both sides of the holder.
• Optical fibres blown into/drawn by suction into respective ducts/pipes by means of the FTTH (Fibre To The Home) technique or by means of the FFTH (Fibre From The Home) technique are preferably numbered or marked in accordance with a prescribed numbering or marking system, for instance using marking tabs or like devices to ensure simple and precise handling ofthe optical fibres.
• the cabinet part A is sealed by means of a sealing strip 7 provided around the edges of the lid 2A.
• a bar 8 Fastened to the underside of the cabinet part 1 A is a bar 8 by means of which the cabinet can be secured to a supportive surface, such as a basement wall or some technically equivalent structure.
• the right-hand cabinet part 1 B houses the active components, such as the switching unit 9 described above with reference to Figure 2, a DC converter 10, a current supply network cable 11, and fans 12 for cooling enclosed components.
• the door opening is provided with especially made, conductive silicone packings 13, and all other openings are optimised to stop electromagnetic radiation so that the unit will satisfy so-called EMC requirements.
• the switching unit 9 can be fitted readily in the cabinet without requiring the use of tools to this end, for instance by exerting a light pressure on a pivotal locking clip.
• a cross-connection unit 14, a so-called CPX can be fitted to the switching unit 9 in the form of long 12 fibre ribbons with tension force relieving means on a front panel of the switching unit.
• eight CPX pigtails having a length of 1.8 m may extend from the switching unit to the cassettes 3, and two or four single mode pigtails for upstream traffic may extend to an external connection point.
• All pigtails may be drawn through one or more holes in an intermediate member between the passive part and the active part, preferably through a hole 16 having a diameter of 5 mm so as to fulfil EMC requirements.
• the intermediate member may comprise at least one side of one of the cabinet parts.
• the cable seals will preferably be made of rubber and the internally fitted jointing cassettes may, for instance, be made of modified PPO with fire protection class UL 94 VO.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Light Guides In General And Applications Therefor (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20278642

Family Applications (1)

Country Status (5)

Cited By (6)

Citations (2)

• 2000
  • 2000-03-01 SE SE0000671A patent/SE516274C2/sv not_active IP Right Cessation
• 2001
  • 2001-02-16 WO PCT/SE2001/000346 patent/WO2001065295A1/en not_active Application Discontinuation
  • 2001-02-16 AU AU2001236275A patent/AU2001236275A1/en not_active Abandoned
  • 2001-02-16 EP EP01908531A patent/EP1269241A1/en not_active Withdrawn
• 2002
  • 2002-08-19 NO NO20023927A patent/NO20023927D0/no not_active Application Discontinuation

Patent Citations (2)

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