BBWF spotlight surprisingly on transmission media

Technical advances at Broadband World Forum (BBWF), held September 27–29 in Paris, surprisingly highlighted copper and non-traditional positioning for wireless and optical fiber (PON). More bandwidth is being squeezed out of copper through introduction of crosstalk cancellation techniques. LTE gateway advances will help vendors position wireless to compete directly with fixed broadband. And the few PON announcements at the event position WDM-PON as a second-mile solution.

Vectoring advances copper, but it’s not a cure-all

The focus on copper is a result of service providers seeking cost-effective ways to support continued subscriber and bandwidth growth. Copper is the largest installed fixed broadband medium, so performance improvements provide an attractive solution.

New life has been breathed into broadband copper solutions by vectoring, which enhances the performance of the copper network by canceling crosstalk, the noise interference that limits bandwidth. The technology requires software and hardware at both the node (DSLAM) and customer premise equipment (CPE). Each line is monitored and analyzed, and a tone is generated to cancel the crosstalk.  

Belgacom already plans to use Alcatel-Lucent’s implementation of this technology (see “Alcatel-Lucent’s VDSL2 vectoring comes of age,” OT00065-003, September 2011). Vectoring can increase VDSL2′s bandwidth to 100Mbps and distances to hundreds of meters. It can also be combined with bonding to provide an additional 70–80% bandwidth increase.

Management of all the copper lines in a bundle or “binder” is required for vectoring to be effective, thereby placing a limitation on its implementation. We saw ASSIA/Ikanos demonstrate enhanced performance of vectored lines when all the copper lines were managed. Cables with unbundled lines represent an area where agreement is needed to benefit from vectoring.

Fixed broadband goes wireless with LTE gateways

The residential LTE gateway, a device that enables Internet access to home networks, untethers users from the conventional broadband wireline connection. The gateway connects to the WAN through the radio access network, which connects to a wired transport network. But the residence fixed broadband no longer means wireline. LTE gateways provide high bandwidth (tens to hundreds of Mbps) to support video, telephony, and data. Transwitch introduced a gateway reference design, and Lantiq (network processor) in collaboration with Altair (LTE chipset) also announced LTE gateway advancement.

Transwitch argues that LTE gateways offer a simpler customer/service provider relationship and significantly reduce operator costs. Previously a truck roll was needed to set up broadband service, but the long-term goal is for consumers to purchase LTE gateways from retail outlets. Service provider costs are further decreased for those who lease lines, since wireless connectivity eliminates the need for such lines.

We also saw numerous home-networking solutions but were particularly impressed with those that use wireless to stream videos in the home. See Qualcomm Atheros’s BBWF announcement of a video-over-wireless (VoW) bridge as an example. Having to run cables for high-bandwidth connectivity is extremely unattractive, but high-performance wireless transmission is challenging. We believe these multi-feature customer premise devices and home gateways are emerging as a new opportunity for vendors.

And fiber for access and the future

WDM-PON is being positioned as a second-mile (access/metro) solution. This is not surprising, as WDM-PON is a cost-effective way to address what may be the next network bandwidth bottleneck.

Transmode’s new WDM-PON product is an OLT transmitter with a schematic that looks remarkably similar to that used by Ericsson. Transmode, Ericsson, and NSN all position WDM-PON as a way to address the new service provider pain-point, congestion in metro/access networks, and not necessarily for residential access. The unifying theme is that more cost-effective solutions are needed in the second mile.