千兆串行/解串器：PON 谜题的关键部分(英)
The recent barrage of such consumer and business-oriented electronics as high definition television, personal video players, network gaming, IP telephony, and video e-mail consoles are all being eyed by the consumer as must-have items. The key enabler for using all of these devices is greater network bandwidth. Consumers worldwide are now quickly filling their homes and workspaces with bandwidth-hogging electronics that need content in order to utilize them. Service providers and content owners want to provide the demanded services especially as these services represent the true growth component of their respective industries.
The main issue blocking service providers and content owners from fulfilling the demands of the bandwidth-hungry consumer is the antiquated copper communication links that connect the majority of today’s consumers to the communication grid. The existing copper infrastructure that connects most consumers and business users to the Internet, and communication grids in general, has reached its capacity in terms of the number of users it can service given all of the new bandwidth-intensive applications that consumers want to use.
Technologies such as xDSL and cable were able to provide copper networks with a much needed bandwidth boost at the start of the Internet era. Now, however, as consumers demand even more bandwidth for applications such as IP-TV and IP-telephony, copper networks simply do not have the bandwidth to meet these demands. The bandwidth situation is exacerbated by the fact that internet usage is becoming ubiquitous. Internet usage penetration rates, in terms of general population usage, are expected to rival those of the telephone and television. This is especially true as computers, televisions and telephones become interconnected.
The end result is that service providers and content owners cannot provide revenue-generating services that their customers demand. On the consumer side, consumers are hesitant to buy more bandwidth-hungry electronics without an outlet to fully utilize their investment. As you can see, the bandwidth issue has repercussions throughout the consumer electronics, computer systems, service provider and content (entertainment) industry’s.
A potential solution
One potential solution to this bandwidth problem that has come to the forefront is Passive Optical Networking technology (PON). PON is a high bandwidth optical point-to-multipoint data access technology that enables data communication using passive optical components such as splitters and Wave Division Multiplexers (WDM).
PON systems typically consist of an Optical Line Termination unit (OLT) which is connected to multiple Optical Networking Terminal units (ONT) at the subscriber (consumer) site. Typically, one OLT can service up to 32-64 ONTs.
PON technology has been available for some time, but only in the past few years have underlying technologies that make up PON become sufficiently cost-effective for widespread implementation. PON, from the service provider’s perspective, enables efficient use of fiber since one link from the central office can service between 32 and 64 subscribers units, depending on the flavor of PON implemented. This results in a lower cost per subscriber in terms of equipment and fiber installation costs.
