V-DSL technology in the NBN

Transcription

1 CommsDay Melbourne Congress 2013 V-DSL technology in the NBN Wednesday 9 th October 2013 Cliff Gibson

2 Outline VDSL2 technologies which extend the capability of existing copper are expected to be included in the mix for delivery of the fixed component of the Australian NBN. Background. Extending the capability of the copper CAN. VDSL 2, how it works, capability and limitations. Potential for VDSL2 and G.fast in Australia's NBN. Desktop estimate of potential customer download speeds. Conclusions. 2

3 Background Many countries are deploying NBNs using a range of fixed and wireless technologies. VDSL2 is a major technology delivering NBNs over existing copper networks NBN is currently being rolled out in Australia to provide FTTP for 93% of the population. International NBN rollouts are employing a blend of technologies including copper. Coalition Broadband plans to continue to build NBN with planned speeds of: 25 to 100Mbps by to 100Mbps by 2019 This new NBN will employ a blend of technologies to deliver broadband to customers. The planned FTTN architecture will employ DSL technologies over copper to 70% of premises This paper focuses on DSL technologies and likely performance of them in the Australian NBN. 3

4 % of total Broadband Subscribers Current Australian broadband services At December 2012 there were 12.2Million broadband subscribers who accessed the internet at a speeds ranging from 256Kbps to over 24 Mbps reflecting the capability of the current networks 50% 45% 44% 40% 35% 35% 30% 25% 20% 15% 14% 10% 5% 2% 5% 0% Less than 256Kbps 256Kbps to 1.5 Mbps ABS Internet Activity, Australia, December Mbps to 8Mbps 8Mbps to 24Mbs Current Broadband access speed Mbps 24 Mbps or Greater 4

5 Digital Subscriber line (DSL) Copper based technology that supports most existing fixed broadband customers Digital Subscriber Line (DSL) is the family of technologies that provide digital data over the copper wires of a local telephone network. The copper telephone network was originally designed for analogue voice signals with a maximum frequency of 3.4 khz. DSL technologies employ frequencies much greater, for example, ADSL2+ supports frequencies up to 2.2 MHz, and VDSL2 supports frequencies up to 30 MHz. Problem is that the twisted pairs exhibit low pass filter properties and the longer the line the greater the attenuation. Higher speeds are only possible over short lengths of cable hence it is important to locate the DSL equipment close to the home to deliver broadband services. 5 DSL technology ITU Standard Download speed capability Asymmetric Digital Subscriber Line (ADSL). G 992.1/2 8 Mbps ADSL 2, G 992.3/4 12 Mbps ADSL 2+ G Mbps Vectored DSL (VDSL) G Mbps VDSL 2 G Mbps G fast G Gbps

6 Vectored DSL (VDSL) Theory VDSL2 Vectoring is standardized by ITU-T as G Self Far End X Talk (FEXT) cancellation vectoring for use with VDSL 2 transceivers. Works by improving the Bandwidth (B) and signal to noise ratio(s/n) which according to the Shannon Theorem will improve the channel capacity C bit/s. Relies on noise-cancellation technology, comparable in concept to the technology found in noise cancelling headphones. With VDSL2 Vectoring, the crosstalk on each line in a cable, is measured, and an anti-phase signal is applied to each line to remove the crosstalk. With VDSL2 Vectoring, every line in a cable can operate at peak performance, as if there were no other VDSL2 lines in that binder. Single entity control of all lines in a group will maximise performance. 6

7 Typical DSL technologies speeds Vary with cable distance 7 Reference Alcatel Lucent

8 VDSL 2 is being implemented now Commercial rollouts 8

9 Future DSL Developments G.fast G.fast, a new ITU broadband standard, that promises up to 1 Gbit/s over existing copper telephone cable pairs. G.fast is designed to deliver superfast downloads up to a distance of 250 meters. G.fast is expected to deliver similar services as those normally requiring fibre to the home FTTP. An important feature of G.fast is that it will enable self-installation by consumers without a technician s assistance and power feed from the customers premises. G.fast promises to provide the speed of fibre with the installation ease of ADSL2. Speeds 500Mb/s for 100m 200Mb/s for 200m 150Mb/s for 250m Standards approval expected March 2014

10 Fibre to the Node (FTTN) and VDSL2 How VDSL2 fits into the NBN Architecture FTTN uses existing copper from the existing Telstra cabinets to the premises. Install VDSL 2 equipment in street cabinets and VDSL 2 modems at the customer premises similar to current ADSL broadband services. Existing phone only services that don t take up broadband can potentially remain on copper. Performance will depend on: Copper cable length. Cable wire size. Quality of cable and cable arrangements e.g. parallel pairs, stubs. Issues Power consumption at the cabinets will likely need AC power and back up batteries but it may be possible to power feed from exchange. Commercially available VDSL 2 CPE typically does not have the 4 Ethernet and 2 phone ports on the NBN NTU. 10

11 Speeds with FTTN and VDSL 2 in Australia GQI Consulting model that estimates the speeds Obtained a file of GNAF addresses for 12m customers. Obtained a CAD file of all Distribution Areas (DA) in Australia. Used CAD to calculate the number of customers in each DA, and area of each DA. Determined the location of cabinets/pillars in each DA and calculated the distance to customers from the cabinet/pillar Determined how many customers were within certain distances from the cabinet/pillar and hence determine potential FTTN speed that could be delivered to them.

12 Telstra s CAN varies state by state e.g. NSW: > 4 million addresses,> 23K DAs, > 90% of addresses < 1km Telstra Exchange Telstra Exchange Boundary Yellow dots are Cabinet locations 12

13 The DAs up closer Telstra s CAN consists of ESAs divided into DAs which are served by pillars/cabinets A node for every few hundred addresses

14 ,000 % of Addresses within the Specified Distance Model outputs 82% of premises are <500 m from the Cabinet and could get speeds of 80Mps 100% Distance from a cabinet/pillar % of Addresses Within Specified Distance 90% 80% 70% 60% 50% 82% access 80 Mbps VDSL 2 40% 30% 20% 10% 0% Distance from a Cabinet (m) 14

15 Conclusions New and emerging technologies will deliver download data speeds approaching and in a couple of years exceeding 100 mbps. Desktop study indicated that approximately 82% of the population could get 80Mbps today with VDSL2. 90% of the population could get 25Mbps today with VDSL. Approximately 55% of the population would be able to get 100+Mbps with G.fast in the near future.