Huawei's technology support mixed FTTN and ADSL deployment

Stuart Corner
Tuesday, 29 April 2008 12:38

Business IT - Technology

The question of whether a fibre to node network can be deployed without cutting off all exchange based ADSL services through a node has been the subject of much debate. Huawei claims that its latest product will enable operators to do exactly this.

Using VDSL2 to deliver services over the last few metres of copper from the fibre node to the customer can create crosstalk interference that will compromise the performance of the ADSL services running from the exchange. Internode managing director Simon Hackett recently challenged   what he described as a myth, central to the current debate in Australia about a future fibre to the node access network: namely that all services running over copper from a current node in the network must be cut over to FTTN simultaneously.

Hackett conceded that "operating VDSL2 equipment mid way along copper cable runs from an exchange creates interference, if it is done at full transmit power over the full spectral mask available," but said that this is not necessary. "VDSL2 deployment performance far in excess of the NBN target performance does not at all depend on operating at full transmit power over the entire spectral mask concerned."

Now Huawei Technologies has released a product which it claims will support the deployment of mixed technology access networks. According to Huawei: "Ensuring reliable performance of copper is an increasing challenge faced by operators to guarantee quality of experience for end-users. Multiple FTTX network topologies with different copper lengths and aging copper loops increase the maintenance effort required, adding to the overall OPEX. Issues arising out of crosstalk and interference seriously impact the performance of DSL, and affect the service rollout."

Huawei's answer is Xpert LAS, billed as "the industry's first hybrid access line assurance solution." Huawei claims that "typically the Xpert LAS improves ADSL2+/ VDSL2 performance by over 30 percent...[and] helps operators to expand their IPTV offerings or other bandwidth-consuming services in the copper bundle."

Huawei says that Xpert LAS "implements the leading DSM (Dynamic Spectra Management) technology based on its innovative APO (Associated Performance Optimisation) algorithm, to solve the DSL crosstalk & interference bottleneck in an efficient and practical way."

DSM is a relatively new technique for optimising performance of DSL services. At Telstra's investor day briefing last November Telstra's chief technology officer, Hugh Bradlow, raised the prospect of Telstra being able to deliver up to 100Mbps using DSL technologies over its existing copper pair network using DSM. "We're already working on the next two generations of copper based technology, VDSL2 and dynamic spectrum management, both of which will increase the speeds by doubling, so that the copper technology has the potential to get up to 100Mbps," Bradlow said.