ZyXEL Communications PLA-470 V2 - V3.0.5 Guia de Instalação descarregar pdf (Página 144)

CHAPTER 7

Equipment

Since the emergence of the HomePlug 1.0 specification in 2003, the PLC network

equipment market has continued to grow. Originally focused on small networks

with a low bit rate and few computers, it then turned to private individuals very

keen on a technology enabling Internet connection sharing while eliminating wiring

constraints and remaining relatively easy to use with the support of Internet access

providers.

This chapter will cover all the PLC products currently available on the market

for connecting terminals to the local area network, to build or to optimize the PLC

network (filters, repeaters, injectors, and so forth).

PLC Technologies

Since the appearance of the first high speed PLC devices, several technologies have

been developed, but no international standard has appeared for the time being.

In the technologies offered to the public, several approaches have been imple-

mented, in particular the following ones:

•

choice of the network mode;

•

modulation techniques;

•

number of sub-bands;

•

MAC layer implementation.

With over 90% of the PLC equipment market, HomePlug technology is so

widespread that it’s becoming the standard product.

The various PLC technologies are summarized in Table 7.1 depending on the

network mode chosen.

The various network modes (master-slave, peer-to-peer, and centralized) are

used by the PLC technologies according to the constraints of each application.

Ascom and Itran were among the first to develop Ethernet interface-based PLC

equipment. They first gave preference to the master-slave mode for its centralized

administration capacities.

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ZyXEL Communications PLA-470 V2 - V3.0.5 Guia de Instalação Página 144