Verizon is the first telecommunications company in the world to successfully field-test a passive optical network system known as XG-PON that can transmit data at 10 gigabits per second (Gbps) downstream and 2.4 Gbps upstream, four times as fast as the current top transmission speeds supporting the company's all-fiber FiOS network.
The test, conducted recently in southern Massachusetts, sets the stage for Verizon to meet the emerging customer demand for a wide variety of devices and applications that require a network capable of transmitting large amounts of data at very high speeds. The devices and applications could include unicast HD video streaming, ultra-high-definition video, 3D video, user-generated content distribution, video conferencing, and new high-speed data services for medium- and large-business customers.
The XG-PON signal was tested independently on a dedicated passive optical network (PON) as well as overlaid on a fiber providing FiOS service to a customer. The overlay test verified there was no interference between the XG-PON signal and the regular FiOS signal using gigabit passive optical network (GPON) technology and running at 2.5 Gbps downstream and 1.24 Gbps upstream.
Previously, Verizon tested the XG-PON signal in the company's Waltham laboratory.
Until now, ITU standards-based XG-PON technology has been tried only in demonstrations and lab trials. Final technical standards for global design and deployment aren't expected until mid 2010. Verizon, however, is working to test and validate the next generation of fiber-to-the-premises (FTTP) technologies from various vendors to help accelerate standards activities, and to ensure that Verizon maintains its leadership in FTTP development and deployment to meet customers' ever-growing bandwidth and service-quality needs.
"From the earliest stages of the FiOS design, we knew we could repeatedly and progressively leverage the immense capacity of fiber to carry more and more data in support of customer applications," said Mark Wegleitner, senior vice president of technology for Verizon. "Now we're already working on the best way to take the next leap forward in capacity."
Wegleitner noted that in 2004 Verizon launched FiOS service using the broadband passive optical network (BPON) technology, which provided downstream speeds of 622 Mbps per second. Less than three years later, the company successfully introduced the gigabit passive optical network, or GPON technology, at speeds that are four times faster than the broadband passive optical network's downstream rate and eight times faster than its upstream rate.
The XG-PON trial, according to Dr. Vincent O'Byrne, director of technology for Verizon, consisted of a new optical line terminal (OLT) installed in the Verizon central office, generating a 10 Gbps XG-PON signal transmitted over a wavelength, or color of light. Two tests were conducted: One test transmitted the XG-PON signal by itself on a separate PON fiber between the central office and a new optical network terminal (ONT) device at a customer's home. In the other test, the XG-PON stream was merged as a separate wavelength onto an already-operating live fiber running FiOS with GPON at 2.5 Gbps to provide a total downstream flow of 12.5 Gbps. At the customer's house, the XG-PON and GPON signals were received by ONT devices, showing that the network can simultaneously deliver the GPON and XG-PON signals on the same fiber at the two speeds, without any degradation in service.
A "test cart" prepared by technical staff from Verizon's FTTP Architecture and Design Group in Waltham was installed at the FiOS customer's house, and was used to exercise the XG-PON information channel. It transmitted and received data service at the XG-PON rate. On the test cart, the signal was demodulated and the performance of the new technology was measured.
O'Byrne said the test is a technology validation, rather than a product trial, affirming the present XG-PON specification and confirming what has been achieved in Verizon's lab.
"This trial is a first for the industry and sets the stage for Verizon to offer increased speeds on the same network currently being used by our GPON customers," said Brian Whitton, executive director of access and video technologies. "This further validates our strategic choice of fiber-to-the-premises as the best way to build a future-proof network."
The trial was conducted with XG-PON equipment from Huawei, a leader in providing next generation telecommunications networks. Future trials with other suppliers' advanced systems are expected over the coming months.