What is the optical edge?

The growing demand of high-bandwidth traffic from end users is encouraging telecom operators to increase the transport capacity of their existing network infrastructure. The so-called “last mile” is the part of the network that reaches end-users’ premises and interconnects them with the first aggregation node. At the aggregation node, end users’ traffic is multiplexed into a higher speed service that will be transmitted up to the core network over DWDM network infrastructure. That portion of the network between the last mile and the core is the “optical edge.” Different broadband access technologies are used in the last mile, such as FTTH, mobile fronthaul or IP. Each of them requires specialized aggregation equipment, such as optical line terminals (OLTs), distributed units (DUs) and routers. But it’s at the optical edge where it all converges. This is where end users’ data is efficiently aggregated before being fed back to the core via optical fiber.

The various devices at the optical edge that aggregate data generated by residential properties, businesses and mobile access have, until recently, required just 10Gbit/s aggregation capability. But, due to the explosion in data demand at the last mile, all of this is changing. Now, because of the huge volume of data traffic that applications such as cloud computing and premium video services are generating, operators are being forced to upgrade last-mile architectures to increase data speeds from 1Gbit/s to 10Gbit/s. This means aggregation speeds at optical edge aggregation nodes must also increase by a factor of ten to 100Gbit/s. It also means every router, every OLT and every single node at the optical edge must now be upgraded. What operators need is a solution that offers a cost-efficient migration path while also boosting scalability and operational simplicity.

The ability to scale the optical edge is vital as more and more data-hungry devices come online and connect to the global digital ecosystem. But with so much legacy equipment to replace, such a move would be cost-prohibitive over the short term. However, coherent, small form-factor pluggable (SFP) transceiver technology offers an affordable way to increase bandwidth over fiber networks while also reducing operational complexity. ADVA’s Coherent 100ZR is the market’s first QSFP28 pluggable device for 100Gbit/s dense wavelength division multiplexing (DWDM) coherent transmission. The solution plugs straight into any QSFP28-based host device, enabling existing network elements to transmit 100Gbit/s signals over long distances. With our Coherent 100ZR, operators can easily expand or upgrade 10Gbit/s optical edge links to 100Gbit/s without the hassle or expense of radically altering existing network infrastructure.