Carriers Choose Packet-Optical

Joining an array of carriers that are moving toward converged packet-optical network archietectures, SK Telecom, South Korea’s largest mobile operator, said it has chosen a packet-optical transport solution from Alcatel-Lucent to upgrade its nationwide mobile data networks. SKT aims to expand its network capacity for existing services, such as WiFi, WiBro (the Korean equivalent of WiMax) and 3G, and to put in place the infrastructure for its upcoming LTE deployments.

That announcement follows the decision of Bouygues Telecom. France’s No. 3 mobile operator, to go with the CN 4200 from Ciena as the packet-optical transport infrastructure for its network upgrade. The Bouygues Telecom deal is of particular interest, said Vincent Morin senior director for Ciena’s transport products, because it includes both wireless and fixed DSL services.

“The combination of wireless and DSL traffic is quite interesting for us because Bouygues went for a significant forklift upgade of their network," said Morin. “They chose the most recent technology for access to much higher capacity and flexibility in the network -- not just in the long-haul, core network but in the metro parts of the network as well."

Those deployments and others based on Optical Transport Network (OTN) technology underline the shift to combined packet-optical transport architectures as carriers – particularly what Morin calls “young, aggressive carriers" – prepare for the upcoming flood of data traffic on mobile networks. Research firm Infonetics released a report earlier this month that found that, while overall network investment has stagnated in the global economic downturn, investment in next-generation converged gear has accelerated.

The ‘Exaflood’ Challenge

"Packet-optical transport systems will be the bedrock of future optical networks," said Andrew Schmitt, Infonetics research director, in a statement.

In the optical network hardware sector and in edge routers, spending on high-speed 40G ports has zoomed upward, added Infonetics principal analyst Michael Howard: “This is the clearest indication yet that service providers are turning to higher-speed options for their next-generation networks to handle skyrocketing traffic."

The packet-optical space received a technological boost earlier this year with the release of Alcatel-Lucent’s new 1870 Transport Tera Switch (TTS). easily the highest-capacity optical switch released to date, the 1870 TTS can switch any mix of OTN, SONET-SDH and Carrier Ethernet traffic on a single platform.

“Faced with an explosion of traffic often called ‘the exaflood challenge,’ the industry has acknowledged the need for additional capacity for bandwidth management and optical switching," pointed out Alberto Valsecchi, VP of marketing for ALU's optical division.

Alcatel-Lucent thus heads a group of network infrastructure makers who in the last year have given operators facing rapidly increasing video and mobile data traffic a powerful set of options for upgrading their networks. According to Infonetics, Fujitsu and Cisco have posted the largest market share gains in the rapidly growing packet-optical sector. These converged boxes allow operators to employ OTN, a set of ITU standards for encapsulating, switching and transporting multiple data types over an optical signal, in order to offload traffic from expensive core routers to less costly optical switches. “OTN adds a new network layer," wrote Ovum research director Ron Kline in a note on the 1870 TTS, “but improves the network’s ability to efficiently handle packet traffic."

Often that means shifting network intelligence from the core of the network further out, closer to the edge.

“These very large aggregator rings now have a significent number of optical channels," explained Morin, “not only at sub-gig bit rates but also at 10G and 40g. The degree of connectivity and complexity is transferring from core to metro, and we have to solve the same set of problems there."

That’s especially true for emerging carriers in densely populated areas, who typically offer hybrid wireless-plus-wireline, residential-plus-enterprise networks. “Most of these young providers have very combined offers," added Morin. With packet-optical systems, “a single network fits all their requirements."