PLC Introduction

Ever since late 1990’s, when NOWEB from England proved that line could transmit data at high rate, in-depth researches on PLC application technology have been carried out worldwide. In recent years, there have emerged many IC development and product manufacturing companies: US Intellon specialized in 14Mbps and 85Mbps chips, Spanish DS2 specialized in 45Mbps and 200Mbps chips, Taiwan Afa offering 50Mbps chips, and French Spidcom offering 224Mbps chips, etc. The 14Mbps chip of US Intellon is mainly designed for more internet application. Due to early rollout and competitive price, it is now most widely used in china and the US.DS2’s chip is mainly designed for broadband access and mediun-voltage(MV)PLC long distance transmission. Its distinctive feature is its network function and network management capability that facilitate operator’s network operation and maintenance. The 50Mbps chip of Afa and 224Mbps chip of Spidcom were rolled out not long ago, and are yet to be tested and improved, and so market share is small.

As for PLC in china, under the guidance of MII, a series of tests and operation trials have been carried out. At present, the PLC broadband access trial operation in Beijing undertook by State Power Telecommunication Center(SPTC) has made satisfactory results, by November 2005, access users in Beijing reached 56524 with a coverage of 600,000 users, forming the largest PLC trial network have extended to over 40 countries and areas in Europe, Asia, North America, South America, Africa and Oceania.

Breakthrough is made in Medium Voltage (MV) PLC Test

When LV Plc test stable development stage, MV PLC technology draws increasing attention worldwide because it enables data transmission between residential user and power converting station by adding coupling devices and communication equipment in American style transformer (380V to 10KV), power switching station and transformers substation (10KV to 35KV/110KV).

Since 2005, thanks to the support of SG, SPTC organized residential test in Beijing and built China’s first MV PLC broadband communication line between power switching station and transformer station. It supports 19Mbps downlink speed, 17Mbps uplink speed and 1Km transmission distance. In Hebei village, call test was made over 10KV line. Within 5Km transmission length, transmission speed reached 1-2Mbps. The combination of MV PLC made it possible to make call through electrical plug in farmer’s house.

MV PLC chip application has wider prospects. In the mean time, MV PLC chip rates mainly include 45Mbps, 200Mbps and 224Mbps. The following are three main applications.

1 Another effective transmission means for constructing power informatization     management platform.

2 To provide high-speed channel from LV PLC broadband access network to local optic ring network.

3 To provide economical and reliable communication means for rural information construction.