Gazettabyte

Vodafone is conducting what is claimed to be the first European field trial of a multi-wavelength passive optical networking system using access equipment from Alcatel-Lucent.

Source: Alcatel-Lucent

The time- and wavelength-division multiplexed passive optical network (TWDM-PON) technology being used is a next-generation access scheme that follows on from 10 gigabit GPON (XG-PON1) and 10 gigabit EPON.

“There appears to be much more 'real' interest in TWDM-PON than in 10G GPON,” says Julie Kunstler, principal analyst, components at Ovum.

The TWDM-PON standard is close to completion in the Full Service Access Network (FSAN) Group and ITU and supports up to eight wavelengths, each capable of 10 gigabit symmetrical or 10/ 2.5 gigabit asymmetrical speeds.

“You can start building hardware solutions that are fully [standard] compliant,” says Stefaan Vanhastel, director of fixed access marketing at Alcatel-Lucent.

TWDM-PON’s support for additional functionality such as dynamic wavelength management, whereby subscribers could be moved between wavelengths, is still being standardised.

The combination of time and wavelength division multiplexing, allows TWDM-PON to support multiple PONs, each sharing its capacity among 16, 32, 64 or even 128 end points depending on the operator’s chosen split ratio.

There appears to be much more 'real' interest in TWDM PON than in 10G GPON

Alcatel-Lucent first detailed its TWDM-PON technology last year. The system vendor introduced a four-wavelength TWDM-PON based on a 4-port line-card, each port supporting a 10 gigabit PON. The line card is used with Alcatel-Lucent’s 7360 Intelligent Services Access Manager FX platform, and supports fixed and tunable SFP optical modules.

“Several vendors also offer the possibility to use fixed wavelength - XG-PON1 or 10G EPON optics," says Vanhastel. "This reduces the initial cost of a TWDM-PON deployment while allowing you to add tunable optics later."

Operators can thus start with a 10 gigabit PON using fixed-wavelength optics and move to TWDM-PON and tunable modules as their capacity needs grow. “You won’t have to swap out legacy XG-PON1 hardware two years from now,” says Vanhastel.

Alcatel-Lucent has been involved in 16 customer TWDM-PON trials overall, half in Asia Pacific and the rest split between North America and EMEA. Besides Vodafone, Alcatel-Lucent has named two other TWDM-PON triallists: Telefonica and Energia, an energy utility in Japan.

You won’t have to swap out legacy XG-PON1 hardware two years from now

Vanhastel says the company has been surprised that operators are also eyeing the technology for residential access. The high capacity and relative expense of tunable optics made the vendor think that early demand would be for business services and mobile backhaul only.

Source: Gazettabyte

There are several reasons for the operator interest in TWDM-PON, says Vanhastel. One is its ample bandwidth - 40 gigabit symmetrical in a four-wavelength implementation - and that wavelengths can be assigned to different aggregation tasks such as backhaul, business and residential. Operators can also pay for wavelengths as needed.

TWDM-PON also allows wavelengths to be shared between operators as part of wholesale agreements. Operators deploying TWDM-PON can lease a wavelength to each other in their respective regions.

Vodafone, for example, is building its own fibre network but is also expanding its overall fixed broadband coverage by developing wholesale agreements across Europe. Vodafone's European broadband network covers 62 million households: 26 million premises covered with its own network and 36 million through wholesale agreements.

First operator TWDM-PON pilot deployments will occur in 2016, says Alcatel-Lucent.