GB2298547A

GB2298547A - Communciations system

Info

Publication number: GB2298547A
Application number: GB9425278A
Authority: GB
Inventors: Michael Philip Dyer; Peter John Dyke
Original assignee: Northern Telecom Ltd
Current assignee: Nortel Networks Ltd
Priority date: 1994-12-14
Filing date: 1994-12-14
Publication date: 1996-09-04
Anticipated expiration: 2014-12-14
Also published as: WO1996019089A1; EP0748574A1; GB2298547B; GB9425278D0

Description

2298547 1 COMMUNICATIONS SYSTEM 1 This invention relates to communications

systems supporting both voice services and broad band services such as broadcast video and videoon- demand. In particular, the invention relates to an apparatus and 5 method for providing subscriber access to those services.

A wide range of narrow band and broad band services are currently available via telecommunications networks. The provision of these services has been greatly facilitated by the introduction of fibre in the loop (FITL) to support these services on a wide band optical carrier. At present these services are generally limited to larger business premises where it is economic to provide a direct fibre connection to the network. However, in numerical terms the large majority of subscribers are either residential or are small business subscribers with a single line or only a small number of lines. these subscribers are coupled to the network via conventional twisted pair subscriber loops and it is generally considered to be uneconomic to replace these wired loops in the foreseeable future with the optical fibre connections that could carry the various services. There are the additional problems that different subscribers will require different services; some may require only a basic POTS service. Also, as service churn introduces new services and modifies current services, there is a potential added cost to the carrier in the introduction of new equipment and the constant need to change equipment to accommodate different service requirements. One approach to this problem has been the introduction of the service adaptive subscriber line card. However, these devices are relatively costly in terms of hardware investment and in engineer time to effect the necessary installation, and can be rendered obsolete by the introduction of new services which are outside the current service adaptive line card capabilities and/or when the subscriber changes his/her service requirements.

It is an object of the invention to minimise or to overcome these 5 disadvantages.

A further object of the invention is to provide a cost-effective network access to a subscriber via a wired subscriber loop.

According to one aspect of the invention there is provided apparatus for coupling a subscriber to a communications network via a wired subscriber loop, the apparatus including a common transceiver unit for coupling to the network and adapted to serve a plurality of subscribers each via a respective subscriber loop, and a subscriber transceiver unit or network termination unit for coupling to the respective subscriber loop and to one or more subscriber terminals, and wherein the common transceiver unit and the subscriber transceiver unit are adapted to provide service independent digital communication over the subscriber loop at downstream and upstream bit rates determined by said transceiver units.

According to another aspect of the invention there is provided a method of providing subscriber access to a communications network via a wired subscriber loop, wherein there are transceiver units one at each end of the loop, the method comprising effecting communication in a service independent digital form over the subscriber loop at downstream and upstream bit rates determined by said transceiver units.

The technique permits the provision of a wide range of services to a small business or a residential subscriber without the need to replace the conventional twisted pair subscriber loop.

Advantageously, the subscriber unit is programmable via the network so that new services and service changes can be introduced without the need to visit the subscriber premises.

Reference is here directed to our copending applications No.9408582.6 and No.9419866.0 which relate to the provision of voice and broad band services in a communications network.

An embodiment of the invention will now be described with reference to the accompanying drawing in which- Figure 1 depicts in schematic form a telecommunications network providing subscriber access over a wired subscriber loop; and Figure 2 shows in further detail the subscriber access equipment of the network of figure 1.

Referring to figure 1, there is shown in schematic form a telecommunications network in which a plurality of services including broad band services are provided over a file to the Kerb system. Typically the network incorporates a trunk network identity, a telecommunications network 11, a broadcastINVOID system 12, broad band services 13 and video on demand (VOD) services 14 and a network management system 15. All these services are coupled to a switch node generally depicted as 16. This switch node may comprise the head end of a fibre optic distribution system to subscribers. The switch node 16 is coupled to a number of primary nodes 17 each typically housed in a street cabinet. Each primary node 17 is in turn coupled to a number of street ONUs 18 which function as common transceiver units providing an interface between fibre optic transmission in the network and electrical transmission to subscribers. Each street ONU distributes signals to subscriber stations 19 over twisted pair or coaxial drops 20 using a digital transmission system which is service independent.

Referring now to figure 2, the subscriber's end of the network is shown in further detail. The subscriber station is provided with a network termination unit 21 which receives digital signals from the ONU 18 over the subscriber loop 20 and transmits digital signals back across the loop to the ONU. The network termination unit disposed at the customer premises may serve, via a broad band line card 210, various items of customer equipment such as a telephone set 22, a facsimile machine 23 and, via a set-top box 24, a television receiver 25. The unit is controlled by a processor 27 and may be powered, e.g. from the domestic electricity supply via a power supply 26.

The street ONU has an optical transmitter 31 and an optical receiver 32 for interfacing with the fibre optic network. Electronic transceivers 33 are provided one for each subscriber. Operation of the ONU is controlled by a processor 34 and electrical power is obtained e.g. from the primary node via a power supply 35. The ONU may also provide emergency electrical power to each subscriber over the subscriber loop e. g. to maintain a basic telephone service in the event of a mains power failure. In some applications, the ONU may provide the sole power source for the subscriber.

The traffic across the subscriber loop between the ONU and the network termination unit is carried in a service independent digital format at a bit rate appropriate to the nature of the traffic. This bit rate may be selected from a set of bit rates comprising e.g. 1 Mb/s, 5 Mb/s, 10 Mb/s and 25 Mb/s. The particular rate to be employed is agreed between the processors in the network termination unit and the ONU respectively. Thus, for a subscriber requiring only a POTS service, the 1 Mb/s rate could be selected as this can easily accommodate a 64 kb/s voice channel. On the other hand, a subscriber requiring e.g. three video channels could be allocated the 25 Mb/s rate. Advantageously, the customer network termination unit is software programmed via the network according to the customer service demand thereby obviating the need for engineer access to the customer premises when new services are introduced or when a change in service mix is required.

The system provides dynamic allocation of both services and bandwidth leading to "service dialtone", and allows equipment in the field and in the customer premises to be independent of service mix. This reduces operational costs associated with new service provisioning and customer churn.

1 -5.

Claims

CLAIMS:-

1. Apparatus for coupling a subscriber to a communications network via a wired subscriber loop, the apparatus including a common transceiver unit for coupling to the network and adapted to serve a plurality of subscribers each via a respective subscriber loop, and a subscriber transceiver unit or network termination unit for coupling to the respective subscriber loop and to one or more subscriber terminals, and wherein the common transceiver unit and the subscriber transceiver unit are adapted to provide service independent digital communication over the subscriber loop at downstream and upstream bit rates determined by said transceiver units.

2. Apparatus as claimed in claim 1, wherein operation of the common transceiver unit and the subscriber transceiver unit are controlled each via a respective processor.

3. Apparatus as claimed in claim 1 or 2, wherein the subscriber transceiver unit is programmable via the network.

4. Apparatus as claimed in claim 1, 2 or 3 wherein the common transceiver unit incorporates means for supplying electrical power to the subscriber transceiver unit across the subscriber loop.

5. Apparatus for coupling a subscriber to a telecommunications network substantially as described herein with reference to and as shown in the accompanying drawings.

6. A method of providing subscriber access to a communications network via a wired subscriber loop, wherein there are transceiver units one at each end of the loop, the method comprising effecting communication in a service independent digital form over the subscriber loop at downstream and upstream bit rates determined by said transceiver units.

7. A method as claimed in claim 6, including providing each subscriber with a network termination unit and programming that unit via the network.

8. A method of providing subscriber access to a communications network substantially as described herein with reference to and as shown in the accompanying drawings.