• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Chapter 1. Introduction > Available Means of Transmission

1.2. Available Means of Transmission

Ethernet [2] can be a good choice for home networking if home-run Category 5 or structured wiring is available. Ethernet can also be installed within a room with twisted pair patch cables. Bob Metcalfe and his Xerox PARC (Palo Alto Research Center) colleagues developed Ethernet in late 1972 to interconnect personal workstations. The IEEE standards for the first version of twisted pair–based Ethernet, 10BaseT, was released during 1990. 10BaseT has a transmission data rate of 10 megabits per second (Mbps) over two pairs of Category 3 or Category 5 twisted pair cable. The first 100-Mbps version of twisted pair–based Ethernet, 100BaseTX, was standardized during 1995. Network Interface Card (NIC), adaptors, and hubs capable of 10BaseT and 100BaseTX (also known as 10/100) Ethernet are available at very affordable costs. The transmission throughput between NICs, adaptors, and a hub is automatically negotiated. 10/100 Ethernet utilizes only two pairs of a Category 5 twisted pair cable. Category 5 wiring is usually terminated with an RJ-45 wall outlet connecting all four pairs or eight wires. The RJ-11 plug of a telephone set can also be plugged into an RJ-45 wall outlet connecting only the four middle pins. The middle two pins of an RJ-11 plug are commonly used by a one-line telephone set. On the other hand, the middle two pins of an RJ-45 plug are not used by 10/100 Ethernet. Therefore, home-run or structured wiring can accommodate both the telephone and the data networking needs of a typical home.

Transmission techniques specified by HomePNA (Home Phoneline Networking Alliance) [3] can be used to connect PCs in homes with many telephone wall outlets. Tut Systems [4] and Epigram, now a home network division of Broadcom, found the existing phone wires in a home a very attractive transmission medium to apply advanced transceiver technologies to. The industrial consortium known as HomePNA was formed in June 1998 to promote the in-home telephone wiring–based transmission technologies. Tut Systems' Pulse Position Modulation (PPM) system was selected in early 1999 as the HomePNA 1.0 line code for a transmission throughput of about 1 Mbps. Epigram's QAM line code was selected later in 1999 as the standard for HomePNA 2.0 with a transmission throughput of up to 10 Mbps. By duplicating the HomePNA 1.0 mechanism, HomePNA 2.0 is also backwards compatible. HomePNA NICs and adaptors were available in stores during 2000 and 2001. They can still be ordered from a few Web sites. Most recently, HomePNA 3.0 with a transmission throughput of up to 100 Mbps has been specified based on technical proposals from Broadcom [5] and CopperGate Communications [6].


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint