ice upstream. Current standards provide the option of symmetric services directly to business customers as well as the option to virtualize PON gear in CORD-equipped central offices. See Table 4-1 for ITU-T (International Telecommunications Union Terminals for Telematic Services) PON standards. Table 4-1 PON Standards PON Type Description Supports a bandwidth of up to 2.5Gbps Enables providers to program individual wavelengths for 10Gbps downstream and 2.5Gbps upstream. www.TechnicalPDF.com Supports 10 Gigabit capacity on both the upstream (from the customer to the central office) and the downstream (from the central office to the customer) signals. Equipment is programmable via software and supports symmetric streams. Providers can program each wavelength individually on a fiber strand, and dedicate it to a large customer. (A wavelength represents a stream of signals on a particular frequency within a fiber strand.) Wavelengths can also be bonded together. Bonding refers to two paths of a communication circuit operating as a single path. This enables the provider to send extra capacity to high-usage enterprises or commercial sites. In the newest PON standard, Next Generation Passive Optical Network 2 (NG PON2), wavelengths can be turned on remotely and the lasers connected to the fiber can be modified SO that the provider is not required to pay for a "truck roll" to send out a technician to make a change at the splitter. According to PON provider Adtran, the ability to add capacity by programming future-proofs NG PON2 against expected increases in traffic, particularly video streaming and cloud computing. As residents' and businesses' broadband use increases, new hardware is not required. Additional capacity for individual wavelengths can be added via software. www.TechnicalPDF.com PON service was initially introduced in North America in 2002. Currently, Adtran, Nokia (through its purchase of Alcatel Lucent), Tellabs, and the Chinese company Huawei manufacture PON components available in North America. Older PON