WO2008088295A2

WO2008088295A2 - Device and method for reduction of operational losses

Info

Publication number: WO2008088295A2
Application number: PCT/SI2008/000004
Authority: WO
Inventors: Matjaz Kolar
Original assignee: Telekom Slovenije D.D.
Priority date: 2007-01-17
Filing date: 2008-01-15
Publication date: 2008-07-24
Also published as: SI22463A; WO2008088295A3

Abstract

Device and method for reduction of operational losses of telecommunication connection solves problem of lack of appropriate bandwidth at final user and providing thereof. The telecommunication operators have soon discovered that decrease in income from existing services (ISDN/PSTN, Internet access...) could not be covered solely by expanding the customer base. Introduction of new services is base for providing of new income. Few years ago 'triplet play' was coined as a word describing package of services including television, telephone services and Internet using wide band network. New kind of services - in particular video (IPTV, VoD...), on-line games,... introduces extraordinary pressure on the operators requiring band width, low response time and introduction of mechanisms enabling sorting of traffic based on priority (QoS). The problem arises as for complete modernization the equipment at the user would need to be changed. The technical problem which is solved with this invention is therefore reduction of operation losses whereas the users can keep their equipment which is solved by erecting at least one xDSL board close to cable terminal.

Description

Device and method for reduction of operational losses

Field of Technology

Telecommunication, data transfer

Technical Problem

Problem to be solved by the present invention is lack of appropriate band width at the final user and its provisions. The telecommunication operators have soon discovered that decrease in income from existing services (ISDN/PSTN, Internet access ...) could not be covered solely by expanding the customer base. Introduction of new services is base for providing of new income. Few years ago "triplet play" was coined as a word describing package of services including television, telephone services and Internet using wide band network. New kind of services - in particular video (IPTV, VoD ...), on-line games, ... introduces extraordinary pressure on the operators requiring band width, low response time and introduction of mechanisms enabling sorting of traffic based on priority (QoS). The problem arises as for complete modernization the equipment at the user would need to be changed. The technical problem which is solved with this invention is therefore reduction of operation losses whereas the users can keep their equipment.

State of the Art

Current architecture of the wide band access which is based on copper conduits is shown in Fig. 1. The figure shows that existing PSTN/ISDN services are joined to wide band services on the splitter, then travel together on the pair (of wires) to cable terminal, and through house installations to the splitter. There, the signal is separated and travels toward DSL modem and ISDN/PSTN equipment. As seen in the figure there is IP BAN (DSLAM - wide band concentrator) which is comprised of aggregation switch and user subscriber boards onto which 32/48 users can be connected. The user subscriber boards are connected to the aggregation switch via Ethernet interfaces (there is also redundancy structure with two switches where each board is connected to primary and redundancy switch).

To provide for necessary bit velocity (speed) in copper access networks one faces problems which are consequence of physical limitations of transfer through copper conduits. Following Shanon theorem one can given band width W and signal/noise ratio (for predetermined BER) achieve bit velocity (R) as given by the equation:

^'bit I s

R = C -UOg₂ (I ₊ ^) = W - 1Og₁ (I + ^-) C = I - W SNR = ^- 1 "N "N Hz P_u

Based on this equation one discovers that bit speed R can be increased in several ways:

with increased band width W and upper border frequency. However, with increase of upper border frequency the operation losses increase (the power of useful signal Ps decreases) which causes the lowering of ration SNR (Signal to Noise Ratio). With increase of the frequency the overhearing loss decreases and in consequence the power of noise increases (P_N) - therefore the ratio SNR additionally decreases, and consequently the SNR additionally decreases and consequently the bit speed, R.

Reduction of noise can be in particular cases achieved with optimum choice of pairs in such a way to ensure minimum influence (interference) of system from neighboring pairs. Actually the systems which are spectrally overlapping are connected to pairs which are as much geometrically apart as possible insofar conditions within the cable allow that. This approach is actual only for solving of individual critical cases, general solution in form of introduction of technologies MIMO, CDMA₅ vectorization ... in deregulated environment (several operators or DSLAM in same access cable) is practically not achievable.

The operational losses increase also with distance between node of operator (DSLAM) and user equipment (modem). Because of this the strength of useful signal (P_s) decreases which results in reduction of SNR and bit speed R. This reduction can be decreased if distance between the node and user equipment is decreased.

In practice one finds also increase of users and their need for higher bit speeds (transmission of video contents) which are in fact two completely different requirements which additionally complicate conditions for copper wire transfer.

Description of new invention

Device and method for reduction of operation losses solves above referenced technical problem by decreasing of distance between operator node and operator equipment reduces operational losses.

For purposes of this application the following abbreviations known in state of the art are used:

IP-BAN Internet Protocol Broadband Access Node

BAN Broadband Access Node xDSL x Digital Subscriber Line (x stands for any, ADSL, VDSL, VDSLl,

VDSL2+, SHDSL or other appropriate technology over digital subscriber line)

IPTV Television over IP network (protocol IP)

VoD Video-on-demand

ISDN Integrated Services Digital Network

PSTN Plain Old Service Telephone Network

QoS Quality of Service

BER Bit Error Rate

MIMO Multiplay Input Multiplay Output

CDMA Code Division Multiplay Access

DSLAM Digital Subscriber Line Multiplexer E/O electro-optical converter

CPE Customer Premises Equipment

SIP Session Initiation Protocol

Softswitch implementation with associated component where the signalization and switching between VOIP (Voice over IP) equipment is performed

DC/DC Direct Current/ Direct Current

AC/DC Alternate Current/ Direct Current

SFP optical module with two fibers

The essence of new invention is setting up xDSL boards of IP BAN in immediate vicinity of existing cable terminals, preferably in high-rise buildings and multi- apartment buildings. xDSL boards are known in state of the art and are therefore not specially described, usually they are in aggregate switch within public telephone central switchboard. Connection between aggregate switch of BAN and the user's board is completed via optical network. Some of the building blocks of IP BAN have anticipated ports which enable input of optical SFP modules whereas some need some degree of intervention. New solution according to invention can be seen in Fig. 2.

Assembly of user's xDSL board can be achieved preferably in two ways:

1. The user's board is mounted (assembled) into specially prepared doors of cable cabinet, for purposes of this application also denoted as "cable terminal (CT)" with passive refrigerator on the outside.

2. The user's board is mounted into special housing in immediate vicinity of CT. The housing of the user's board and CT are interconnected via metal channel.

The example of modified doors of cable object is seen in Fig. 3.

After board installation the optical fibers are connected whereas the user's board is connected with aggregate switch using optical connection (E/O converter).

On appropriate connectors (rails) inside CT on one side the house installation is terminated while on the side of the network the ports of xDSL board are terminated on the connectors (rails) whereby the elastic connection of xDSL broadband port on arbitrary connection of house installation (user's) exit is enabled. For existing PSTN/ ISDN services the functions of the node are emulated in CPE equipment (emulation of PSTN/ ISDN port), whereby they are transferred over SIP protocol to Softswitch (in this architecture the splitters are not needed).

The supply of the user's board is implemented preferably remote over copper pairs which are released and can be used for power supply after the user (house installation) takes advantage of connection directly onto the user's board which has been transferred onto the building (object) - as illustrated in Fig.2. For purposes of remote supply in preferred embodiment 10 pairs are released (meaning that in preferred embodiment 10 broadband users per each location is needed) through which 150W of power is ensured (the consumption of 32 port board is 70W). To reduce the losses one should consider DC/DC converters for remote supply. Invention according to the patent is therefore further characterized by remote power supply of at least one xDSL user's board in vicinity of at least one cable terminal, using copper pairs which have been released from use because of start of use of optical cable.

In some cases in vicinity CT one finds connecting point to public electric supply system network. In such case local power supply station can be erected, this supply station used for power supply of vicinity buildings as shown in Fig. 4. In such case the invention is additionally characterized by having multiple apartment building or plurality thereof supplied with power from central power supply in vicinity of connecting point to public electric supply system network.

Below the essence of the invention is further explained with description of figures whereas the figures form integral part of this patent application.

Figure 1 shows state of the art: symbol for Triple Play as descriptor of complex telecommunication technology despite the patent is not limited to this technology 1, aggregate switch with user's boards 2, physical depiction of boards 3, DSLAM 4, backbone network 5, public telecommunication central 6, users in multiple apartment building 7, equipment at particular user whereas the equipment comprises of at least one of the following: modem, computer, telephone, television set 8, copper pairs 9, cable terminal 10.

Figure 2 shows new invention as follows: symbol for Triple Play as descriptor of complex telecommunication technology 1, aggregate switch with user's boards 2, physical depiction of boards 3, DSLAM 4, backbone network 5, public telecommunication central 6, users in multiple apartment building 7, equipment at particular user whereas the equipment comprises of at least one of the following: modem, computer, telephone, television set 8, copper pairs 9, cable terminal 10, symbolic way of transfer from the aggregate switch to just before cable terminal 11, optical fibers 12, xDSL user's subscriber board 13, AC/DC converter 14.

Figure 3 shows solution of cable cabinet, namely DC/DC converter for remote power supply 15, the rails used for connection to DSL ports of the board and termination of house installation 16, copper pairs for remote power supply 10, xDSL subscriber board 13, E/O converter 17, optical fiber 12.

Figure 4 shows solution of power supply of the neighborhood 18.

Claims

PATENT CLAIMS

1. Device for reduction of operational losses of telecommunication connection between telecommunication services operator and user, characterized in that it comprises aggregate switch (2), connection between aggregate switch (2) and at least subscriber xDSL board (13) in essentially immediate vicinity of at least one cable terminal (10) using optical fibre or plurality thereof (12).

2. Device according to claim 1, characterized in that the multiple apartment building or plurality thereof is supplied from central power supply unit in vicinity of connecting point of public electrical supply network.

3. Device according to any of the preceding claims, characterized in that the power supply of at least one xDSL subsrcriber board (13) in vicinity of at least one cable terminal (10) is implemented remotely with copper pairs (9) which have been released by using connection via optical fibre or plurality thereof (12).

4. Device according to any of the preceding claims, characterized in that elastic xDSL broadband port with any exit of house installation is enabled by terminating house installation on rails (16) of cable terminal (10) on one side, and by terminating ports of xDSL board (13) on rails (16) of cable terminal (10) on another side

5. Device according to any of the preceding claims, characterized in that for existing PSTN/ISDN services functions of a node are emulated in CPE equipment (emulation of PSTN/ISDN port), and further that they are transmitted over SIP protocol to Softswitch.

6. Method for reduction of operational losses of telecommunication connection between telecommunication services operator and user, characterized in that at least one xDSL board (13) is transferred into immediate vicinity of at least one cable terminal (10) and is connected to public telecommunication switch (6) or aggregate switch (2) by means of optical fibre or plurality thereof (12).