Sunday 7 October 2007

The GPON Standard

Towards the end of 2008, HSDPA+ will offer up to 28mbps download and 5,8mbps upload speeds, and in the second half of 2009, HSDPA++ will offer 42 mbps download and 12 mbps upload speeds. In the same year long-tern evolution (LTE) technology will push mobile data throughput to 100 mbps download and 50 mbps upload speeds and take the networks from 3G to 4G technology.
Another broadband technology in the pipeline is Gigabit Passive Optical Networks (GPON), which will provide high-speed fibre cable to the home at 100 mbps over distances up to 20km, and will be available in two to three years time. Unfortunately with so many technologies in evolution it is difficult to kep track of all the new things happening in Telecom world but here is my attempt to explore these new technologies.
In April Freescale made the following press release:
The delivery of rich digital content to the home and small office via fiber takes a major step toward reality today with the introduction of the MSC7120 from Freescale Semiconductor – the industry’s first voice-enabled Gigabit Passive Optical Networking (GPON) SoC.

The multi-core MSC7120 integrates a Power Architecture™ CPU, a StarCore™ DSP and a data path engine to deliver a complete PON sub-system in a single device. It addresses the high data forwarding throughput requirements of several applications including the delivery of “triple play” (voice, video and data) broadband services to the home or small business.
GPON technology supports the convergence of IP over optical networks, offering connection speeds much higher than today’s DSL- or DOCSIS-based networks. It is a key enabler for bandwidth-hungry “triple play” applications such as HDTV and Video on Demand.

Analyst firm IDC forecasts that worldwide consumer and small business broadband subscriptions will grow to approximately 400M subscriptions by 2010.

As the number of broadband subscribers worldwide expands, GPON is recognized as an emerging solution to challenges that threaten to constrict delivery of rich content to end consumers over “last mile” infrastructure.

“Over the next few years, GPON technology will become a viable solution for increasing bandwidth in today's access networks, especially as carriers address the increasing demand for video as a key element of their ‘triple play’ services,” said Aileen Arcilla, senior research analyst at IDC.
Wikipedia has good introduction on PON standards:
Early work on efficient fiber to the home architectures was done in the 1990s by the Full Service Access Network (FSAN) working group, formed by major telecommunications service providers and system vendors. The International Telecommunications Union (ITU) did further work, and has since standardized on two generations of PON. The older ITU-T G.983 standard is based on asynchronous transfer mode (ATM), and has therefore been referred to as APON (ATM PON). Further improvements to the original APON standard – as well as the gradual falling out of favor of ATM as a protocol – led to the full, final version of ITU-T G.983 being referred to more often as broadband PON, or BPON. A typical APON/BPON provides 622 megabits per second (Mbit/s) of downstream bandwidth and 155 Mbit/s of upstream traffic, although the standard accommodates higher rates.

The ITU-T G.984 (GPON) standard represents a boost in both the total bandwidth and bandwidth efficiency through the use of larger, variable-length packets. Again, the standards permit several choices of bit rate, but the industry has converged on 2,488 Mbits per second (Mbit/s) of downstream bandwidth, and 1,244 Mbit/s of upstream bandwidth. GPON Encapsulation Method (GEM) allows very efficient packaging of user traffic, with frame segmentation to allow for higher Quality of Service (QoS) for delay-sensitive traffic such as voice and video communications.
Some Applications of GPON can be found here.

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